File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/Alignment.h |
Warning: | line 85, column 47 The result of the left shift is undefined due to shifting by '255', which is greater or equal to the width of type 'uint64_t' |
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1 | //===- AttributorAttributes.cpp - Attributes for Attributor deduction -----===// | |||
2 | // | |||
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |||
4 | // See https://llvm.org/LICENSE.txt for license information. | |||
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |||
6 | // | |||
7 | //===----------------------------------------------------------------------===// | |||
8 | // | |||
9 | // See the Attributor.h file comment and the class descriptions in that file for | |||
10 | // more information. | |||
11 | // | |||
12 | //===----------------------------------------------------------------------===// | |||
13 | ||||
14 | #include "llvm/Transforms/IPO/Attributor.h" | |||
15 | ||||
16 | #include "llvm/ADT/APInt.h" | |||
17 | #include "llvm/ADT/SCCIterator.h" | |||
18 | #include "llvm/ADT/SmallPtrSet.h" | |||
19 | #include "llvm/ADT/Statistic.h" | |||
20 | #include "llvm/Analysis/AliasAnalysis.h" | |||
21 | #include "llvm/Analysis/AssumeBundleQueries.h" | |||
22 | #include "llvm/Analysis/AssumptionCache.h" | |||
23 | #include "llvm/Analysis/CaptureTracking.h" | |||
24 | #include "llvm/Analysis/InstructionSimplify.h" | |||
25 | #include "llvm/Analysis/LazyValueInfo.h" | |||
26 | #include "llvm/Analysis/MemoryBuiltins.h" | |||
27 | #include "llvm/Analysis/OptimizationRemarkEmitter.h" | |||
28 | #include "llvm/Analysis/ScalarEvolution.h" | |||
29 | #include "llvm/Analysis/TargetTransformInfo.h" | |||
30 | #include "llvm/Analysis/ValueTracking.h" | |||
31 | #include "llvm/IR/Constants.h" | |||
32 | #include "llvm/IR/IRBuilder.h" | |||
33 | #include "llvm/IR/Instruction.h" | |||
34 | #include "llvm/IR/Instructions.h" | |||
35 | #include "llvm/IR/IntrinsicInst.h" | |||
36 | #include "llvm/IR/NoFolder.h" | |||
37 | #include "llvm/Support/Alignment.h" | |||
38 | #include "llvm/Support/Casting.h" | |||
39 | #include "llvm/Support/CommandLine.h" | |||
40 | #include "llvm/Support/ErrorHandling.h" | |||
41 | #include "llvm/Support/FileSystem.h" | |||
42 | #include "llvm/Support/raw_ostream.h" | |||
43 | #include "llvm/Transforms/IPO/ArgumentPromotion.h" | |||
44 | #include "llvm/Transforms/Utils/Local.h" | |||
45 | #include <cassert> | |||
46 | ||||
47 | using namespace llvm; | |||
48 | ||||
49 | #define DEBUG_TYPE"attributor" "attributor" | |||
50 | ||||
51 | static cl::opt<bool> ManifestInternal( | |||
52 | "attributor-manifest-internal", cl::Hidden, | |||
53 | cl::desc("Manifest Attributor internal string attributes."), | |||
54 | cl::init(false)); | |||
55 | ||||
56 | static cl::opt<int> MaxHeapToStackSize("max-heap-to-stack-size", cl::init(128), | |||
57 | cl::Hidden); | |||
58 | ||||
59 | template <> | |||
60 | unsigned llvm::PotentialConstantIntValuesState::MaxPotentialValues = 0; | |||
61 | ||||
62 | static cl::opt<unsigned, true> MaxPotentialValues( | |||
63 | "attributor-max-potential-values", cl::Hidden, | |||
64 | cl::desc("Maximum number of potential values to be " | |||
65 | "tracked for each position."), | |||
66 | cl::location(llvm::PotentialConstantIntValuesState::MaxPotentialValues), | |||
67 | cl::init(7)); | |||
68 | ||||
69 | STATISTIC(NumAAs, "Number of abstract attributes created")static llvm::Statistic NumAAs = {"attributor", "NumAAs", "Number of abstract attributes created" }; | |||
70 | ||||
71 | // Some helper macros to deal with statistics tracking. | |||
72 | // | |||
73 | // Usage: | |||
74 | // For simple IR attribute tracking overload trackStatistics in the abstract | |||
75 | // attribute and choose the right STATS_DECLTRACK_********* macro, | |||
76 | // e.g.,: | |||
77 | // void trackStatistics() const override { | |||
78 | // STATS_DECLTRACK_ARG_ATTR(returned) | |||
79 | // } | |||
80 | // If there is a single "increment" side one can use the macro | |||
81 | // STATS_DECLTRACK with a custom message. If there are multiple increment | |||
82 | // sides, STATS_DECL and STATS_TRACK can also be used separately. | |||
83 | // | |||
84 | #define BUILD_STAT_MSG_IR_ATTR(TYPE, NAME)("Number of " "TYPE" " marked '" "NAME" "'") \ | |||
85 | ("Number of " #TYPE " marked '" #NAME "'") | |||
86 | #define BUILD_STAT_NAME(NAME, TYPE)NumIRTYPE_NAME NumIR##TYPE##_##NAME | |||
87 | #define STATS_DECL_(NAME, MSG)static llvm::Statistic NAME = {"attributor", "NAME", MSG}; STATISTIC(NAME, MSG)static llvm::Statistic NAME = {"attributor", "NAME", MSG}; | |||
88 | #define STATS_DECL(NAME, TYPE, MSG)static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; \ | |||
89 | STATS_DECL_(BUILD_STAT_NAME(NAME, TYPE), MSG)static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; | |||
90 | #define STATS_TRACK(NAME, TYPE)++(NumIRTYPE_NAME); ++(BUILD_STAT_NAME(NAME, TYPE)NumIRTYPE_NAME); | |||
91 | #define STATS_DECLTRACK(NAME, TYPE, MSG){ static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; ++(NumIRTYPE_NAME); } \ | |||
92 | { \ | |||
93 | STATS_DECL(NAME, TYPE, MSG)static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; \ | |||
94 | STATS_TRACK(NAME, TYPE)++(NumIRTYPE_NAME); \ | |||
95 | } | |||
96 | #define STATS_DECLTRACK_ARG_ATTR(NAME){ static llvm::Statistic NumIRArguments_NAME = {"attributor", "NumIRArguments_NAME", ("Number of " "arguments" " marked '" "NAME" "'")};; ++(NumIRArguments_NAME); } \ | |||
97 | STATS_DECLTRACK(NAME, Arguments, BUILD_STAT_MSG_IR_ATTR(arguments, NAME)){ static llvm::Statistic NumIRArguments_NAME = {"attributor", "NumIRArguments_NAME", ("Number of " "arguments" " marked '" "NAME" "'")};; ++(NumIRArguments_NAME); } | |||
98 | #define STATS_DECLTRACK_CSARG_ATTR(NAME){ static llvm::Statistic NumIRCSArguments_NAME = {"attributor" , "NumIRCSArguments_NAME", ("Number of " "call site arguments" " marked '" "NAME" "'")};; ++(NumIRCSArguments_NAME); } \ | |||
99 | STATS_DECLTRACK(NAME, CSArguments, \{ static llvm::Statistic NumIRCSArguments_NAME = {"attributor" , "NumIRCSArguments_NAME", ("Number of " "call site arguments" " marked '" "NAME" "'")};; ++(NumIRCSArguments_NAME); } | |||
100 | BUILD_STAT_MSG_IR_ATTR(call site arguments, NAME)){ static llvm::Statistic NumIRCSArguments_NAME = {"attributor" , "NumIRCSArguments_NAME", ("Number of " "call site arguments" " marked '" "NAME" "'")};; ++(NumIRCSArguments_NAME); } | |||
101 | #define STATS_DECLTRACK_FN_ATTR(NAME){ static llvm::Statistic NumIRFunction_NAME = {"attributor", "NumIRFunction_NAME" , ("Number of " "functions" " marked '" "NAME" "'")};; ++(NumIRFunction_NAME ); } \ | |||
102 | STATS_DECLTRACK(NAME, Function, BUILD_STAT_MSG_IR_ATTR(functions, NAME)){ static llvm::Statistic NumIRFunction_NAME = {"attributor", "NumIRFunction_NAME" , ("Number of " "functions" " marked '" "NAME" "'")};; ++(NumIRFunction_NAME ); } | |||
103 | #define STATS_DECLTRACK_CS_ATTR(NAME){ static llvm::Statistic NumIRCS_NAME = {"attributor", "NumIRCS_NAME" , ("Number of " "call site" " marked '" "NAME" "'")};; ++(NumIRCS_NAME ); } \ | |||
104 | STATS_DECLTRACK(NAME, CS, BUILD_STAT_MSG_IR_ATTR(call site, NAME)){ static llvm::Statistic NumIRCS_NAME = {"attributor", "NumIRCS_NAME" , ("Number of " "call site" " marked '" "NAME" "'")};; ++(NumIRCS_NAME ); } | |||
105 | #define STATS_DECLTRACK_FNRET_ATTR(NAME){ static llvm::Statistic NumIRFunctionReturn_NAME = {"attributor" , "NumIRFunctionReturn_NAME", ("Number of " "function returns" " marked '" "NAME" "'")};; ++(NumIRFunctionReturn_NAME); } \ | |||
106 | STATS_DECLTRACK(NAME, FunctionReturn, \{ static llvm::Statistic NumIRFunctionReturn_NAME = {"attributor" , "NumIRFunctionReturn_NAME", ("Number of " "function returns" " marked '" "NAME" "'")};; ++(NumIRFunctionReturn_NAME); } | |||
107 | BUILD_STAT_MSG_IR_ATTR(function returns, NAME)){ static llvm::Statistic NumIRFunctionReturn_NAME = {"attributor" , "NumIRFunctionReturn_NAME", ("Number of " "function returns" " marked '" "NAME" "'")};; ++(NumIRFunctionReturn_NAME); } | |||
108 | #define STATS_DECLTRACK_CSRET_ATTR(NAME){ static llvm::Statistic NumIRCSReturn_NAME = {"attributor", "NumIRCSReturn_NAME" , ("Number of " "call site returns" " marked '" "NAME" "'")}; ; ++(NumIRCSReturn_NAME); } \ | |||
109 | STATS_DECLTRACK(NAME, CSReturn, \{ static llvm::Statistic NumIRCSReturn_NAME = {"attributor", "NumIRCSReturn_NAME" , ("Number of " "call site returns" " marked '" "NAME" "'")}; ; ++(NumIRCSReturn_NAME); } | |||
110 | BUILD_STAT_MSG_IR_ATTR(call site returns, NAME)){ static llvm::Statistic NumIRCSReturn_NAME = {"attributor", "NumIRCSReturn_NAME" , ("Number of " "call site returns" " marked '" "NAME" "'")}; ; ++(NumIRCSReturn_NAME); } | |||
111 | #define STATS_DECLTRACK_FLOATING_ATTR(NAME){ static llvm::Statistic NumIRFloating_NAME = {"attributor", "NumIRFloating_NAME" , ("Number of floating values known to be '" "NAME" "'")};; ++ (NumIRFloating_NAME); } \ | |||
112 | STATS_DECLTRACK(NAME, Floating, \{ static llvm::Statistic NumIRFloating_NAME = {"attributor", "NumIRFloating_NAME" , ("Number of floating values known to be '" #NAME "'")};; ++ (NumIRFloating_NAME); } | |||
113 | ("Number of floating values known to be '" #NAME "'")){ static llvm::Statistic NumIRFloating_NAME = {"attributor", "NumIRFloating_NAME" , ("Number of floating values known to be '" #NAME "'")};; ++ (NumIRFloating_NAME); } | |||
114 | ||||
115 | // Specialization of the operator<< for abstract attributes subclasses. This | |||
116 | // disambiguates situations where multiple operators are applicable. | |||
117 | namespace llvm { | |||
118 | #define PIPE_OPERATOR(CLASS) \ | |||
119 | raw_ostream &operator<<(raw_ostream &OS, const CLASS &AA) { \ | |||
120 | return OS << static_cast<const AbstractAttribute &>(AA); \ | |||
121 | } | |||
122 | ||||
123 | PIPE_OPERATOR(AAIsDead) | |||
124 | PIPE_OPERATOR(AANoUnwind) | |||
125 | PIPE_OPERATOR(AANoSync) | |||
126 | PIPE_OPERATOR(AANoRecurse) | |||
127 | PIPE_OPERATOR(AAWillReturn) | |||
128 | PIPE_OPERATOR(AANoReturn) | |||
129 | PIPE_OPERATOR(AAReturnedValues) | |||
130 | PIPE_OPERATOR(AANonNull) | |||
131 | PIPE_OPERATOR(AANoAlias) | |||
132 | PIPE_OPERATOR(AADereferenceable) | |||
133 | PIPE_OPERATOR(AAAlign) | |||
134 | PIPE_OPERATOR(AANoCapture) | |||
135 | PIPE_OPERATOR(AAValueSimplify) | |||
136 | PIPE_OPERATOR(AANoFree) | |||
137 | PIPE_OPERATOR(AAHeapToStack) | |||
138 | PIPE_OPERATOR(AAReachability) | |||
139 | PIPE_OPERATOR(AAMemoryBehavior) | |||
140 | PIPE_OPERATOR(AAMemoryLocation) | |||
141 | PIPE_OPERATOR(AAValueConstantRange) | |||
142 | PIPE_OPERATOR(AAPrivatizablePtr) | |||
143 | PIPE_OPERATOR(AAUndefinedBehavior) | |||
144 | PIPE_OPERATOR(AAPotentialValues) | |||
145 | PIPE_OPERATOR(AANoUndef) | |||
146 | PIPE_OPERATOR(AACallEdges) | |||
147 | PIPE_OPERATOR(AAFunctionReachability) | |||
148 | PIPE_OPERATOR(AAPointerInfo) | |||
149 | ||||
150 | #undef PIPE_OPERATOR | |||
151 | ||||
152 | template <> | |||
153 | ChangeStatus clampStateAndIndicateChange<DerefState>(DerefState &S, | |||
154 | const DerefState &R) { | |||
155 | ChangeStatus CS0 = | |||
156 | clampStateAndIndicateChange(S.DerefBytesState, R.DerefBytesState); | |||
157 | ChangeStatus CS1 = clampStateAndIndicateChange(S.GlobalState, R.GlobalState); | |||
158 | return CS0 | CS1; | |||
159 | } | |||
160 | ||||
161 | } // namespace llvm | |||
162 | ||||
163 | /// Get pointer operand of memory accessing instruction. If \p I is | |||
164 | /// not a memory accessing instruction, return nullptr. If \p AllowVolatile, | |||
165 | /// is set to false and the instruction is volatile, return nullptr. | |||
166 | static const Value *getPointerOperand(const Instruction *I, | |||
167 | bool AllowVolatile) { | |||
168 | if (!AllowVolatile && I->isVolatile()) | |||
169 | return nullptr; | |||
170 | ||||
171 | if (auto *LI = dyn_cast<LoadInst>(I)) { | |||
172 | return LI->getPointerOperand(); | |||
173 | } | |||
174 | ||||
175 | if (auto *SI = dyn_cast<StoreInst>(I)) { | |||
176 | return SI->getPointerOperand(); | |||
177 | } | |||
178 | ||||
179 | if (auto *CXI = dyn_cast<AtomicCmpXchgInst>(I)) { | |||
180 | return CXI->getPointerOperand(); | |||
181 | } | |||
182 | ||||
183 | if (auto *RMWI = dyn_cast<AtomicRMWInst>(I)) { | |||
184 | return RMWI->getPointerOperand(); | |||
185 | } | |||
186 | ||||
187 | return nullptr; | |||
188 | } | |||
189 | ||||
190 | /// Helper function to create a pointer of type \p ResTy, based on \p Ptr, and | |||
191 | /// advanced by \p Offset bytes. To aid later analysis the method tries to build | |||
192 | /// getelement pointer instructions that traverse the natural type of \p Ptr if | |||
193 | /// possible. If that fails, the remaining offset is adjusted byte-wise, hence | |||
194 | /// through a cast to i8*. | |||
195 | /// | |||
196 | /// TODO: This could probably live somewhere more prominantly if it doesn't | |||
197 | /// already exist. | |||
198 | static Value *constructPointer(Type *ResTy, Type *PtrElemTy, Value *Ptr, | |||
199 | int64_t Offset, IRBuilder<NoFolder> &IRB, | |||
200 | const DataLayout &DL) { | |||
201 | assert(Offset >= 0 && "Negative offset not supported yet!")((void)0); | |||
202 | LLVM_DEBUG(dbgs() << "Construct pointer: " << *Ptr << " + " << Offsetdo { } while (false) | |||
203 | << "-bytes as " << *ResTy << "\n")do { } while (false); | |||
204 | ||||
205 | if (Offset) { | |||
206 | SmallVector<Value *, 4> Indices; | |||
207 | std::string GEPName = Ptr->getName().str() + ".0"; | |||
208 | ||||
209 | // Add 0 index to look through the pointer. | |||
210 | assert((uint64_t)Offset < DL.getTypeAllocSize(PtrElemTy) &&((void)0) | |||
211 | "Offset out of bounds")((void)0); | |||
212 | Indices.push_back(Constant::getNullValue(IRB.getInt32Ty())); | |||
213 | ||||
214 | Type *Ty = PtrElemTy; | |||
215 | do { | |||
216 | auto *STy = dyn_cast<StructType>(Ty); | |||
217 | if (!STy) | |||
218 | // Non-aggregate type, we cast and make byte-wise progress now. | |||
219 | break; | |||
220 | ||||
221 | const StructLayout *SL = DL.getStructLayout(STy); | |||
222 | if (int64_t(SL->getSizeInBytes()) < Offset) | |||
223 | break; | |||
224 | ||||
225 | uint64_t Idx = SL->getElementContainingOffset(Offset); | |||
226 | assert(Idx < STy->getNumElements() && "Offset calculation error!")((void)0); | |||
227 | uint64_t Rem = Offset - SL->getElementOffset(Idx); | |||
228 | Ty = STy->getElementType(Idx); | |||
229 | ||||
230 | LLVM_DEBUG(errs() << "Ty: " << *Ty << " Offset: " << Offsetdo { } while (false) | |||
231 | << " Idx: " << Idx << " Rem: " << Rem << "\n")do { } while (false); | |||
232 | ||||
233 | GEPName += "." + std::to_string(Idx); | |||
234 | Indices.push_back(ConstantInt::get(IRB.getInt32Ty(), Idx)); | |||
235 | Offset = Rem; | |||
236 | } while (Offset); | |||
237 | ||||
238 | // Create a GEP for the indices collected above. | |||
239 | Ptr = IRB.CreateGEP(PtrElemTy, Ptr, Indices, GEPName); | |||
240 | ||||
241 | // If an offset is left we use byte-wise adjustment. | |||
242 | if (Offset) { | |||
243 | Ptr = IRB.CreateBitCast(Ptr, IRB.getInt8PtrTy()); | |||
244 | Ptr = IRB.CreateGEP(IRB.getInt8Ty(), Ptr, IRB.getInt32(Offset), | |||
245 | GEPName + ".b" + Twine(Offset)); | |||
246 | } | |||
247 | } | |||
248 | ||||
249 | // Ensure the result has the requested type. | |||
250 | Ptr = IRB.CreateBitOrPointerCast(Ptr, ResTy, Ptr->getName() + ".cast"); | |||
251 | ||||
252 | LLVM_DEBUG(dbgs() << "Constructed pointer: " << *Ptr << "\n")do { } while (false); | |||
253 | return Ptr; | |||
254 | } | |||
255 | ||||
256 | /// Recursively visit all values that might become \p IRP at some point. This | |||
257 | /// will be done by looking through cast instructions, selects, phis, and calls | |||
258 | /// with the "returned" attribute. Once we cannot look through the value any | |||
259 | /// further, the callback \p VisitValueCB is invoked and passed the current | |||
260 | /// value, the \p State, and a flag to indicate if we stripped anything. | |||
261 | /// Stripped means that we unpacked the value associated with \p IRP at least | |||
262 | /// once. Note that the value used for the callback may still be the value | |||
263 | /// associated with \p IRP (due to PHIs). To limit how much effort is invested, | |||
264 | /// we will never visit more values than specified by \p MaxValues. | |||
265 | template <typename StateTy> | |||
266 | static bool genericValueTraversal( | |||
267 | Attributor &A, IRPosition IRP, const AbstractAttribute &QueryingAA, | |||
268 | StateTy &State, | |||
269 | function_ref<bool(Value &, const Instruction *, StateTy &, bool)> | |||
270 | VisitValueCB, | |||
271 | const Instruction *CtxI, bool UseValueSimplify = true, int MaxValues = 16, | |||
272 | function_ref<Value *(Value *)> StripCB = nullptr) { | |||
273 | ||||
274 | const AAIsDead *LivenessAA = nullptr; | |||
275 | if (IRP.getAnchorScope()) | |||
276 | LivenessAA = &A.getAAFor<AAIsDead>( | |||
277 | QueryingAA, | |||
278 | IRPosition::function(*IRP.getAnchorScope(), IRP.getCallBaseContext()), | |||
279 | DepClassTy::NONE); | |||
280 | bool AnyDead = false; | |||
281 | ||||
282 | Value *InitialV = &IRP.getAssociatedValue(); | |||
283 | using Item = std::pair<Value *, const Instruction *>; | |||
284 | SmallSet<Item, 16> Visited; | |||
285 | SmallVector<Item, 16> Worklist; | |||
286 | Worklist.push_back({InitialV, CtxI}); | |||
287 | ||||
288 | int Iteration = 0; | |||
289 | do { | |||
290 | Item I = Worklist.pop_back_val(); | |||
291 | Value *V = I.first; | |||
292 | CtxI = I.second; | |||
293 | if (StripCB) | |||
294 | V = StripCB(V); | |||
295 | ||||
296 | // Check if we should process the current value. To prevent endless | |||
297 | // recursion keep a record of the values we followed! | |||
298 | if (!Visited.insert(I).second) | |||
299 | continue; | |||
300 | ||||
301 | // Make sure we limit the compile time for complex expressions. | |||
302 | if (Iteration++ >= MaxValues) | |||
303 | return false; | |||
304 | ||||
305 | // Explicitly look through calls with a "returned" attribute if we do | |||
306 | // not have a pointer as stripPointerCasts only works on them. | |||
307 | Value *NewV = nullptr; | |||
308 | if (V->getType()->isPointerTy()) { | |||
309 | NewV = V->stripPointerCasts(); | |||
310 | } else { | |||
311 | auto *CB = dyn_cast<CallBase>(V); | |||
312 | if (CB && CB->getCalledFunction()) { | |||
313 | for (Argument &Arg : CB->getCalledFunction()->args()) | |||
314 | if (Arg.hasReturnedAttr()) { | |||
315 | NewV = CB->getArgOperand(Arg.getArgNo()); | |||
316 | break; | |||
317 | } | |||
318 | } | |||
319 | } | |||
320 | if (NewV && NewV != V) { | |||
321 | Worklist.push_back({NewV, CtxI}); | |||
322 | continue; | |||
323 | } | |||
324 | ||||
325 | // Look through select instructions, visit assumed potential values. | |||
326 | if (auto *SI = dyn_cast<SelectInst>(V)) { | |||
327 | bool UsedAssumedInformation = false; | |||
328 | Optional<Constant *> C = A.getAssumedConstant( | |||
329 | *SI->getCondition(), QueryingAA, UsedAssumedInformation); | |||
330 | bool NoValueYet = !C.hasValue(); | |||
331 | if (NoValueYet || isa_and_nonnull<UndefValue>(*C)) | |||
332 | continue; | |||
333 | if (auto *CI = dyn_cast_or_null<ConstantInt>(*C)) { | |||
334 | if (CI->isZero()) | |||
335 | Worklist.push_back({SI->getFalseValue(), CtxI}); | |||
336 | else | |||
337 | Worklist.push_back({SI->getTrueValue(), CtxI}); | |||
338 | continue; | |||
339 | } | |||
340 | // We could not simplify the condition, assume both values.( | |||
341 | Worklist.push_back({SI->getTrueValue(), CtxI}); | |||
342 | Worklist.push_back({SI->getFalseValue(), CtxI}); | |||
343 | continue; | |||
344 | } | |||
345 | ||||
346 | // Look through phi nodes, visit all live operands. | |||
347 | if (auto *PHI = dyn_cast<PHINode>(V)) { | |||
348 | assert(LivenessAA &&((void)0) | |||
349 | "Expected liveness in the presence of instructions!")((void)0); | |||
350 | for (unsigned u = 0, e = PHI->getNumIncomingValues(); u < e; u++) { | |||
351 | BasicBlock *IncomingBB = PHI->getIncomingBlock(u); | |||
352 | bool UsedAssumedInformation = false; | |||
353 | if (A.isAssumedDead(*IncomingBB->getTerminator(), &QueryingAA, | |||
354 | LivenessAA, UsedAssumedInformation, | |||
355 | /* CheckBBLivenessOnly */ true)) { | |||
356 | AnyDead = true; | |||
357 | continue; | |||
358 | } | |||
359 | Worklist.push_back( | |||
360 | {PHI->getIncomingValue(u), IncomingBB->getTerminator()}); | |||
361 | } | |||
362 | continue; | |||
363 | } | |||
364 | ||||
365 | if (UseValueSimplify && !isa<Constant>(V)) { | |||
366 | bool UsedAssumedInformation = false; | |||
367 | Optional<Value *> SimpleV = | |||
368 | A.getAssumedSimplified(*V, QueryingAA, UsedAssumedInformation); | |||
369 | if (!SimpleV.hasValue()) | |||
370 | continue; | |||
371 | if (!SimpleV.getValue()) | |||
372 | return false; | |||
373 | Value *NewV = SimpleV.getValue(); | |||
374 | if (NewV != V) { | |||
375 | Worklist.push_back({NewV, CtxI}); | |||
376 | continue; | |||
377 | } | |||
378 | } | |||
379 | ||||
380 | // Once a leaf is reached we inform the user through the callback. | |||
381 | if (!VisitValueCB(*V, CtxI, State, Iteration > 1)) | |||
382 | return false; | |||
383 | } while (!Worklist.empty()); | |||
384 | ||||
385 | // If we actually used liveness information so we have to record a dependence. | |||
386 | if (AnyDead) | |||
387 | A.recordDependence(*LivenessAA, QueryingAA, DepClassTy::OPTIONAL); | |||
388 | ||||
389 | // All values have been visited. | |||
390 | return true; | |||
391 | } | |||
392 | ||||
393 | bool AA::getAssumedUnderlyingObjects(Attributor &A, const Value &Ptr, | |||
394 | SmallVectorImpl<Value *> &Objects, | |||
395 | const AbstractAttribute &QueryingAA, | |||
396 | const Instruction *CtxI) { | |||
397 | auto StripCB = [&](Value *V) { return getUnderlyingObject(V); }; | |||
398 | SmallPtrSet<Value *, 8> SeenObjects; | |||
399 | auto VisitValueCB = [&SeenObjects](Value &Val, const Instruction *, | |||
400 | SmallVectorImpl<Value *> &Objects, | |||
401 | bool) -> bool { | |||
402 | if (SeenObjects.insert(&Val).second) | |||
403 | Objects.push_back(&Val); | |||
404 | return true; | |||
405 | }; | |||
406 | if (!genericValueTraversal<decltype(Objects)>( | |||
407 | A, IRPosition::value(Ptr), QueryingAA, Objects, VisitValueCB, CtxI, | |||
408 | true, 32, StripCB)) | |||
409 | return false; | |||
410 | return true; | |||
411 | } | |||
412 | ||||
413 | const Value *stripAndAccumulateMinimalOffsets( | |||
414 | Attributor &A, const AbstractAttribute &QueryingAA, const Value *Val, | |||
415 | const DataLayout &DL, APInt &Offset, bool AllowNonInbounds, | |||
416 | bool UseAssumed = false) { | |||
417 | ||||
418 | auto AttributorAnalysis = [&](Value &V, APInt &ROffset) -> bool { | |||
419 | const IRPosition &Pos = IRPosition::value(V); | |||
420 | // Only track dependence if we are going to use the assumed info. | |||
421 | const AAValueConstantRange &ValueConstantRangeAA = | |||
422 | A.getAAFor<AAValueConstantRange>(QueryingAA, Pos, | |||
423 | UseAssumed ? DepClassTy::OPTIONAL | |||
424 | : DepClassTy::NONE); | |||
425 | ConstantRange Range = UseAssumed ? ValueConstantRangeAA.getAssumed() | |||
426 | : ValueConstantRangeAA.getKnown(); | |||
427 | // We can only use the lower part of the range because the upper part can | |||
428 | // be higher than what the value can really be. | |||
429 | ROffset = Range.getSignedMin(); | |||
430 | return true; | |||
431 | }; | |||
432 | ||||
433 | return Val->stripAndAccumulateConstantOffsets(DL, Offset, AllowNonInbounds, | |||
434 | AttributorAnalysis); | |||
435 | } | |||
436 | ||||
437 | static const Value *getMinimalBaseOfAccsesPointerOperand( | |||
438 | Attributor &A, const AbstractAttribute &QueryingAA, const Instruction *I, | |||
439 | int64_t &BytesOffset, const DataLayout &DL, bool AllowNonInbounds = false) { | |||
440 | const Value *Ptr = getPointerOperand(I, /* AllowVolatile */ false); | |||
441 | if (!Ptr) | |||
442 | return nullptr; | |||
443 | APInt OffsetAPInt(DL.getIndexTypeSizeInBits(Ptr->getType()), 0); | |||
444 | const Value *Base = stripAndAccumulateMinimalOffsets( | |||
445 | A, QueryingAA, Ptr, DL, OffsetAPInt, AllowNonInbounds); | |||
446 | ||||
447 | BytesOffset = OffsetAPInt.getSExtValue(); | |||
448 | return Base; | |||
449 | } | |||
450 | ||||
451 | static const Value * | |||
452 | getBasePointerOfAccessPointerOperand(const Instruction *I, int64_t &BytesOffset, | |||
453 | const DataLayout &DL, | |||
454 | bool AllowNonInbounds = false) { | |||
455 | const Value *Ptr = getPointerOperand(I, /* AllowVolatile */ false); | |||
456 | if (!Ptr) | |||
457 | return nullptr; | |||
458 | ||||
459 | return GetPointerBaseWithConstantOffset(Ptr, BytesOffset, DL, | |||
460 | AllowNonInbounds); | |||
461 | } | |||
462 | ||||
463 | /// Clamp the information known for all returned values of a function | |||
464 | /// (identified by \p QueryingAA) into \p S. | |||
465 | template <typename AAType, typename StateType = typename AAType::StateType> | |||
466 | static void clampReturnedValueStates( | |||
467 | Attributor &A, const AAType &QueryingAA, StateType &S, | |||
468 | const IRPosition::CallBaseContext *CBContext = nullptr) { | |||
469 | LLVM_DEBUG(dbgs() << "[Attributor] Clamp return value states for "do { } while (false) | |||
470 | << QueryingAA << " into " << S << "\n")do { } while (false); | |||
471 | ||||
472 | assert((QueryingAA.getIRPosition().getPositionKind() ==((void)0) | |||
473 | IRPosition::IRP_RETURNED ||((void)0) | |||
474 | QueryingAA.getIRPosition().getPositionKind() ==((void)0) | |||
475 | IRPosition::IRP_CALL_SITE_RETURNED) &&((void)0) | |||
476 | "Can only clamp returned value states for a function returned or call "((void)0) | |||
477 | "site returned position!")((void)0); | |||
478 | ||||
479 | // Use an optional state as there might not be any return values and we want | |||
480 | // to join (IntegerState::operator&) the state of all there are. | |||
481 | Optional<StateType> T; | |||
482 | ||||
483 | // Callback for each possibly returned value. | |||
484 | auto CheckReturnValue = [&](Value &RV) -> bool { | |||
485 | const IRPosition &RVPos = IRPosition::value(RV, CBContext); | |||
486 | const AAType &AA = | |||
487 | A.getAAFor<AAType>(QueryingAA, RVPos, DepClassTy::REQUIRED); | |||
488 | LLVM_DEBUG(dbgs() << "[Attributor] RV: " << RV << " AA: " << AA.getAsStr()do { } while (false) | |||
489 | << " @ " << RVPos << "\n")do { } while (false); | |||
490 | const StateType &AAS = AA.getState(); | |||
491 | if (T.hasValue()) | |||
492 | *T &= AAS; | |||
493 | else | |||
494 | T = AAS; | |||
495 | LLVM_DEBUG(dbgs() << "[Attributor] AA State: " << AAS << " RV State: " << Tdo { } while (false) | |||
496 | << "\n")do { } while (false); | |||
497 | return T->isValidState(); | |||
498 | }; | |||
499 | ||||
500 | if (!A.checkForAllReturnedValues(CheckReturnValue, QueryingAA)) | |||
501 | S.indicatePessimisticFixpoint(); | |||
502 | else if (T.hasValue()) | |||
503 | S ^= *T; | |||
504 | } | |||
505 | ||||
506 | /// Helper class for generic deduction: return value -> returned position. | |||
507 | template <typename AAType, typename BaseType, | |||
508 | typename StateType = typename BaseType::StateType, | |||
509 | bool PropagateCallBaseContext = false> | |||
510 | struct AAReturnedFromReturnedValues : public BaseType { | |||
511 | AAReturnedFromReturnedValues(const IRPosition &IRP, Attributor &A) | |||
512 | : BaseType(IRP, A) {} | |||
513 | ||||
514 | /// See AbstractAttribute::updateImpl(...). | |||
515 | ChangeStatus updateImpl(Attributor &A) override { | |||
516 | StateType S(StateType::getBestState(this->getState())); | |||
517 | clampReturnedValueStates<AAType, StateType>( | |||
518 | A, *this, S, | |||
519 | PropagateCallBaseContext ? this->getCallBaseContext() : nullptr); | |||
520 | // TODO: If we know we visited all returned values, thus no are assumed | |||
521 | // dead, we can take the known information from the state T. | |||
522 | return clampStateAndIndicateChange<StateType>(this->getState(), S); | |||
523 | } | |||
524 | }; | |||
525 | ||||
526 | /// Clamp the information known at all call sites for a given argument | |||
527 | /// (identified by \p QueryingAA) into \p S. | |||
528 | template <typename AAType, typename StateType = typename AAType::StateType> | |||
529 | static void clampCallSiteArgumentStates(Attributor &A, const AAType &QueryingAA, | |||
530 | StateType &S) { | |||
531 | LLVM_DEBUG(dbgs() << "[Attributor] Clamp call site argument states for "do { } while (false) | |||
532 | << QueryingAA << " into " << S << "\n")do { } while (false); | |||
533 | ||||
534 | assert(QueryingAA.getIRPosition().getPositionKind() ==((void)0) | |||
535 | IRPosition::IRP_ARGUMENT &&((void)0) | |||
536 | "Can only clamp call site argument states for an argument position!")((void)0); | |||
537 | ||||
538 | // Use an optional state as there might not be any return values and we want | |||
539 | // to join (IntegerState::operator&) the state of all there are. | |||
540 | Optional<StateType> T; | |||
541 | ||||
542 | // The argument number which is also the call site argument number. | |||
543 | unsigned ArgNo = QueryingAA.getIRPosition().getCallSiteArgNo(); | |||
544 | ||||
545 | auto CallSiteCheck = [&](AbstractCallSite ACS) { | |||
546 | const IRPosition &ACSArgPos = IRPosition::callsite_argument(ACS, ArgNo); | |||
547 | // Check if a coresponding argument was found or if it is on not associated | |||
548 | // (which can happen for callback calls). | |||
549 | if (ACSArgPos.getPositionKind() == IRPosition::IRP_INVALID) | |||
550 | return false; | |||
551 | ||||
552 | const AAType &AA = | |||
553 | A.getAAFor<AAType>(QueryingAA, ACSArgPos, DepClassTy::REQUIRED); | |||
554 | LLVM_DEBUG(dbgs() << "[Attributor] ACS: " << *ACS.getInstruction()do { } while (false) | |||
555 | << " AA: " << AA.getAsStr() << " @" << ACSArgPos << "\n")do { } while (false); | |||
556 | const StateType &AAS = AA.getState(); | |||
557 | if (T.hasValue()) | |||
558 | *T &= AAS; | |||
559 | else | |||
560 | T = AAS; | |||
561 | LLVM_DEBUG(dbgs() << "[Attributor] AA State: " << AAS << " CSA State: " << Tdo { } while (false) | |||
562 | << "\n")do { } while (false); | |||
563 | return T->isValidState(); | |||
564 | }; | |||
565 | ||||
566 | bool AllCallSitesKnown; | |||
567 | if (!A.checkForAllCallSites(CallSiteCheck, QueryingAA, true, | |||
568 | AllCallSitesKnown)) | |||
569 | S.indicatePessimisticFixpoint(); | |||
570 | else if (T.hasValue()) | |||
571 | S ^= *T; | |||
572 | } | |||
573 | ||||
574 | /// This function is the bridge between argument position and the call base | |||
575 | /// context. | |||
576 | template <typename AAType, typename BaseType, | |||
577 | typename StateType = typename AAType::StateType> | |||
578 | bool getArgumentStateFromCallBaseContext(Attributor &A, | |||
579 | BaseType &QueryingAttribute, | |||
580 | IRPosition &Pos, StateType &State) { | |||
581 | assert((Pos.getPositionKind() == IRPosition::IRP_ARGUMENT) &&((void)0) | |||
582 | "Expected an 'argument' position !")((void)0); | |||
583 | const CallBase *CBContext = Pos.getCallBaseContext(); | |||
584 | if (!CBContext) | |||
585 | return false; | |||
586 | ||||
587 | int ArgNo = Pos.getCallSiteArgNo(); | |||
588 | assert(ArgNo >= 0 && "Invalid Arg No!")((void)0); | |||
589 | ||||
590 | const auto &AA = A.getAAFor<AAType>( | |||
591 | QueryingAttribute, IRPosition::callsite_argument(*CBContext, ArgNo), | |||
592 | DepClassTy::REQUIRED); | |||
593 | const StateType &CBArgumentState = | |||
594 | static_cast<const StateType &>(AA.getState()); | |||
595 | ||||
596 | LLVM_DEBUG(dbgs() << "[Attributor] Briding Call site context to argument"do { } while (false) | |||
597 | << "Position:" << Pos << "CB Arg state:" << CBArgumentStatedo { } while (false) | |||
598 | << "\n")do { } while (false); | |||
599 | ||||
600 | // NOTE: If we want to do call site grouping it should happen here. | |||
601 | State ^= CBArgumentState; | |||
602 | return true; | |||
603 | } | |||
604 | ||||
605 | /// Helper class for generic deduction: call site argument -> argument position. | |||
606 | template <typename AAType, typename BaseType, | |||
607 | typename StateType = typename AAType::StateType, | |||
608 | bool BridgeCallBaseContext = false> | |||
609 | struct AAArgumentFromCallSiteArguments : public BaseType { | |||
610 | AAArgumentFromCallSiteArguments(const IRPosition &IRP, Attributor &A) | |||
611 | : BaseType(IRP, A) {} | |||
612 | ||||
613 | /// See AbstractAttribute::updateImpl(...). | |||
614 | ChangeStatus updateImpl(Attributor &A) override { | |||
615 | StateType S = StateType::getBestState(this->getState()); | |||
616 | ||||
617 | if (BridgeCallBaseContext) { | |||
618 | bool Success = | |||
619 | getArgumentStateFromCallBaseContext<AAType, BaseType, StateType>( | |||
620 | A, *this, this->getIRPosition(), S); | |||
621 | if (Success) | |||
622 | return clampStateAndIndicateChange<StateType>(this->getState(), S); | |||
623 | } | |||
624 | clampCallSiteArgumentStates<AAType, StateType>(A, *this, S); | |||
625 | ||||
626 | // TODO: If we know we visited all incoming values, thus no are assumed | |||
627 | // dead, we can take the known information from the state T. | |||
628 | return clampStateAndIndicateChange<StateType>(this->getState(), S); | |||
629 | } | |||
630 | }; | |||
631 | ||||
632 | /// Helper class for generic replication: function returned -> cs returned. | |||
633 | template <typename AAType, typename BaseType, | |||
634 | typename StateType = typename BaseType::StateType, | |||
635 | bool IntroduceCallBaseContext = false> | |||
636 | struct AACallSiteReturnedFromReturned : public BaseType { | |||
637 | AACallSiteReturnedFromReturned(const IRPosition &IRP, Attributor &A) | |||
638 | : BaseType(IRP, A) {} | |||
639 | ||||
640 | /// See AbstractAttribute::updateImpl(...). | |||
641 | ChangeStatus updateImpl(Attributor &A) override { | |||
642 | assert(this->getIRPosition().getPositionKind() ==((void)0) | |||
643 | IRPosition::IRP_CALL_SITE_RETURNED &&((void)0) | |||
644 | "Can only wrap function returned positions for call site returned "((void)0) | |||
645 | "positions!")((void)0); | |||
646 | auto &S = this->getState(); | |||
647 | ||||
648 | const Function *AssociatedFunction = | |||
649 | this->getIRPosition().getAssociatedFunction(); | |||
650 | if (!AssociatedFunction) | |||
651 | return S.indicatePessimisticFixpoint(); | |||
652 | ||||
653 | CallBase &CBContext = static_cast<CallBase &>(this->getAnchorValue()); | |||
654 | if (IntroduceCallBaseContext) | |||
655 | LLVM_DEBUG(dbgs() << "[Attributor] Introducing call base context:"do { } while (false) | |||
656 | << CBContext << "\n")do { } while (false); | |||
657 | ||||
658 | IRPosition FnPos = IRPosition::returned( | |||
659 | *AssociatedFunction, IntroduceCallBaseContext ? &CBContext : nullptr); | |||
660 | const AAType &AA = A.getAAFor<AAType>(*this, FnPos, DepClassTy::REQUIRED); | |||
661 | return clampStateAndIndicateChange(S, AA.getState()); | |||
662 | } | |||
663 | }; | |||
664 | ||||
665 | /// Helper function to accumulate uses. | |||
666 | template <class AAType, typename StateType = typename AAType::StateType> | |||
667 | static void followUsesInContext(AAType &AA, Attributor &A, | |||
668 | MustBeExecutedContextExplorer &Explorer, | |||
669 | const Instruction *CtxI, | |||
670 | SetVector<const Use *> &Uses, | |||
671 | StateType &State) { | |||
672 | auto EIt = Explorer.begin(CtxI), EEnd = Explorer.end(CtxI); | |||
673 | for (unsigned u = 0; u < Uses.size(); ++u) { | |||
674 | const Use *U = Uses[u]; | |||
675 | if (const Instruction *UserI = dyn_cast<Instruction>(U->getUser())) { | |||
676 | bool Found = Explorer.findInContextOf(UserI, EIt, EEnd); | |||
677 | if (Found && AA.followUseInMBEC(A, U, UserI, State)) | |||
678 | for (const Use &Us : UserI->uses()) | |||
679 | Uses.insert(&Us); | |||
680 | } | |||
681 | } | |||
682 | } | |||
683 | ||||
684 | /// Use the must-be-executed-context around \p I to add information into \p S. | |||
685 | /// The AAType class is required to have `followUseInMBEC` method with the | |||
686 | /// following signature and behaviour: | |||
687 | /// | |||
688 | /// bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I) | |||
689 | /// U - Underlying use. | |||
690 | /// I - The user of the \p U. | |||
691 | /// Returns true if the value should be tracked transitively. | |||
692 | /// | |||
693 | template <class AAType, typename StateType = typename AAType::StateType> | |||
694 | static void followUsesInMBEC(AAType &AA, Attributor &A, StateType &S, | |||
695 | Instruction &CtxI) { | |||
696 | ||||
697 | // Container for (transitive) uses of the associated value. | |||
698 | SetVector<const Use *> Uses; | |||
699 | for (const Use &U : AA.getIRPosition().getAssociatedValue().uses()) | |||
700 | Uses.insert(&U); | |||
701 | ||||
702 | MustBeExecutedContextExplorer &Explorer = | |||
703 | A.getInfoCache().getMustBeExecutedContextExplorer(); | |||
704 | ||||
705 | followUsesInContext<AAType>(AA, A, Explorer, &CtxI, Uses, S); | |||
706 | ||||
707 | if (S.isAtFixpoint()) | |||
708 | return; | |||
709 | ||||
710 | SmallVector<const BranchInst *, 4> BrInsts; | |||
711 | auto Pred = [&](const Instruction *I) { | |||
712 | if (const BranchInst *Br = dyn_cast<BranchInst>(I)) | |||
713 | if (Br->isConditional()) | |||
714 | BrInsts.push_back(Br); | |||
715 | return true; | |||
716 | }; | |||
717 | ||||
718 | // Here, accumulate conditional branch instructions in the context. We | |||
719 | // explore the child paths and collect the known states. The disjunction of | |||
720 | // those states can be merged to its own state. Let ParentState_i be a state | |||
721 | // to indicate the known information for an i-th branch instruction in the | |||
722 | // context. ChildStates are created for its successors respectively. | |||
723 | // | |||
724 | // ParentS_1 = ChildS_{1, 1} /\ ChildS_{1, 2} /\ ... /\ ChildS_{1, n_1} | |||
725 | // ParentS_2 = ChildS_{2, 1} /\ ChildS_{2, 2} /\ ... /\ ChildS_{2, n_2} | |||
726 | // ... | |||
727 | // ParentS_m = ChildS_{m, 1} /\ ChildS_{m, 2} /\ ... /\ ChildS_{m, n_m} | |||
728 | // | |||
729 | // Known State |= ParentS_1 \/ ParentS_2 \/... \/ ParentS_m | |||
730 | // | |||
731 | // FIXME: Currently, recursive branches are not handled. For example, we | |||
732 | // can't deduce that ptr must be dereferenced in below function. | |||
733 | // | |||
734 | // void f(int a, int c, int *ptr) { | |||
735 | // if(a) | |||
736 | // if (b) { | |||
737 | // *ptr = 0; | |||
738 | // } else { | |||
739 | // *ptr = 1; | |||
740 | // } | |||
741 | // else { | |||
742 | // if (b) { | |||
743 | // *ptr = 0; | |||
744 | // } else { | |||
745 | // *ptr = 1; | |||
746 | // } | |||
747 | // } | |||
748 | // } | |||
749 | ||||
750 | Explorer.checkForAllContext(&CtxI, Pred); | |||
751 | for (const BranchInst *Br : BrInsts) { | |||
752 | StateType ParentState; | |||
753 | ||||
754 | // The known state of the parent state is a conjunction of children's | |||
755 | // known states so it is initialized with a best state. | |||
756 | ParentState.indicateOptimisticFixpoint(); | |||
757 | ||||
758 | for (const BasicBlock *BB : Br->successors()) { | |||
759 | StateType ChildState; | |||
760 | ||||
761 | size_t BeforeSize = Uses.size(); | |||
762 | followUsesInContext(AA, A, Explorer, &BB->front(), Uses, ChildState); | |||
763 | ||||
764 | // Erase uses which only appear in the child. | |||
765 | for (auto It = Uses.begin() + BeforeSize; It != Uses.end();) | |||
766 | It = Uses.erase(It); | |||
767 | ||||
768 | ParentState &= ChildState; | |||
769 | } | |||
770 | ||||
771 | // Use only known state. | |||
772 | S += ParentState; | |||
773 | } | |||
774 | } | |||
775 | ||||
776 | /// ------------------------ PointerInfo --------------------------------------- | |||
777 | ||||
778 | namespace llvm { | |||
779 | namespace AA { | |||
780 | namespace PointerInfo { | |||
781 | ||||
782 | /// An access kind description as used by AAPointerInfo. | |||
783 | struct OffsetAndSize; | |||
784 | ||||
785 | struct State; | |||
786 | ||||
787 | } // namespace PointerInfo | |||
788 | } // namespace AA | |||
789 | ||||
790 | /// Helper for AA::PointerInfo::Acccess DenseMap/Set usage. | |||
791 | template <> | |||
792 | struct DenseMapInfo<AAPointerInfo::Access> : DenseMapInfo<Instruction *> { | |||
793 | using Access = AAPointerInfo::Access; | |||
794 | static inline Access getEmptyKey(); | |||
795 | static inline Access getTombstoneKey(); | |||
796 | static unsigned getHashValue(const Access &A); | |||
797 | static bool isEqual(const Access &LHS, const Access &RHS); | |||
798 | }; | |||
799 | ||||
800 | /// Helper that allows OffsetAndSize as a key in a DenseMap. | |||
801 | template <> | |||
802 | struct DenseMapInfo<AA::PointerInfo ::OffsetAndSize> | |||
803 | : DenseMapInfo<std::pair<int64_t, int64_t>> {}; | |||
804 | ||||
805 | /// Helper for AA::PointerInfo::Acccess DenseMap/Set usage ignoring everythign | |||
806 | /// but the instruction | |||
807 | struct AccessAsInstructionInfo : DenseMapInfo<Instruction *> { | |||
808 | using Base = DenseMapInfo<Instruction *>; | |||
809 | using Access = AAPointerInfo::Access; | |||
810 | static inline Access getEmptyKey(); | |||
811 | static inline Access getTombstoneKey(); | |||
812 | static unsigned getHashValue(const Access &A); | |||
813 | static bool isEqual(const Access &LHS, const Access &RHS); | |||
814 | }; | |||
815 | ||||
816 | } // namespace llvm | |||
817 | ||||
818 | /// Helper to represent an access offset and size, with logic to deal with | |||
819 | /// uncertainty and check for overlapping accesses. | |||
820 | struct AA::PointerInfo::OffsetAndSize : public std::pair<int64_t, int64_t> { | |||
821 | using BaseTy = std::pair<int64_t, int64_t>; | |||
822 | OffsetAndSize(int64_t Offset, int64_t Size) : BaseTy(Offset, Size) {} | |||
823 | OffsetAndSize(const BaseTy &P) : BaseTy(P) {} | |||
824 | int64_t getOffset() const { return first; } | |||
825 | int64_t getSize() const { return second; } | |||
826 | static OffsetAndSize getUnknown() { return OffsetAndSize(Unknown, Unknown); } | |||
827 | ||||
828 | /// Return true if this offset and size pair might describe an address that | |||
829 | /// overlaps with \p OAS. | |||
830 | bool mayOverlap(const OffsetAndSize &OAS) const { | |||
831 | // Any unknown value and we are giving up -> overlap. | |||
832 | if (OAS.getOffset() == OffsetAndSize::Unknown || | |||
833 | OAS.getSize() == OffsetAndSize::Unknown || | |||
834 | getOffset() == OffsetAndSize::Unknown || | |||
835 | getSize() == OffsetAndSize::Unknown) | |||
836 | return true; | |||
837 | ||||
838 | // Check if one offset point is in the other interval [offset, offset+size]. | |||
839 | return OAS.getOffset() + OAS.getSize() > getOffset() && | |||
840 | OAS.getOffset() < getOffset() + getSize(); | |||
841 | } | |||
842 | ||||
843 | /// Constant used to represent unknown offset or sizes. | |||
844 | static constexpr int64_t Unknown = 1 << 31; | |||
845 | }; | |||
846 | ||||
847 | /// Implementation of the DenseMapInfo. | |||
848 | /// | |||
849 | ///{ | |||
850 | inline llvm::AccessAsInstructionInfo::Access | |||
851 | llvm::AccessAsInstructionInfo::getEmptyKey() { | |||
852 | return Access(Base::getEmptyKey(), nullptr, AAPointerInfo::AK_READ, nullptr); | |||
853 | } | |||
854 | inline llvm::AccessAsInstructionInfo::Access | |||
855 | llvm::AccessAsInstructionInfo::getTombstoneKey() { | |||
856 | return Access(Base::getTombstoneKey(), nullptr, AAPointerInfo::AK_READ, | |||
857 | nullptr); | |||
858 | } | |||
859 | unsigned llvm::AccessAsInstructionInfo::getHashValue( | |||
860 | const llvm::AccessAsInstructionInfo::Access &A) { | |||
861 | return Base::getHashValue(A.getRemoteInst()); | |||
862 | } | |||
863 | bool llvm::AccessAsInstructionInfo::isEqual( | |||
864 | const llvm::AccessAsInstructionInfo::Access &LHS, | |||
865 | const llvm::AccessAsInstructionInfo::Access &RHS) { | |||
866 | return LHS.getRemoteInst() == RHS.getRemoteInst(); | |||
867 | } | |||
868 | inline llvm::DenseMapInfo<AAPointerInfo::Access>::Access | |||
869 | llvm::DenseMapInfo<AAPointerInfo::Access>::getEmptyKey() { | |||
870 | return AAPointerInfo::Access(nullptr, nullptr, AAPointerInfo::AK_READ, | |||
871 | nullptr); | |||
872 | } | |||
873 | inline llvm::DenseMapInfo<AAPointerInfo::Access>::Access | |||
874 | llvm::DenseMapInfo<AAPointerInfo::Access>::getTombstoneKey() { | |||
875 | return AAPointerInfo::Access(nullptr, nullptr, AAPointerInfo::AK_WRITE, | |||
876 | nullptr); | |||
877 | } | |||
878 | ||||
879 | unsigned llvm::DenseMapInfo<AAPointerInfo::Access>::getHashValue( | |||
880 | const llvm::DenseMapInfo<AAPointerInfo::Access>::Access &A) { | |||
881 | return detail::combineHashValue( | |||
882 | DenseMapInfo<Instruction *>::getHashValue(A.getRemoteInst()), | |||
883 | (A.isWrittenValueYetUndetermined() | |||
884 | ? ~0 | |||
885 | : DenseMapInfo<Value *>::getHashValue(A.getWrittenValue()))) + | |||
886 | A.getKind(); | |||
887 | } | |||
888 | ||||
889 | bool llvm::DenseMapInfo<AAPointerInfo::Access>::isEqual( | |||
890 | const llvm::DenseMapInfo<AAPointerInfo::Access>::Access &LHS, | |||
891 | const llvm::DenseMapInfo<AAPointerInfo::Access>::Access &RHS) { | |||
892 | return LHS == RHS; | |||
893 | } | |||
894 | ///} | |||
895 | ||||
896 | /// A type to track pointer/struct usage and accesses for AAPointerInfo. | |||
897 | struct AA::PointerInfo::State : public AbstractState { | |||
898 | ||||
899 | /// Return the best possible representable state. | |||
900 | static State getBestState(const State &SIS) { return State(); } | |||
901 | ||||
902 | /// Return the worst possible representable state. | |||
903 | static State getWorstState(const State &SIS) { | |||
904 | State R; | |||
905 | R.indicatePessimisticFixpoint(); | |||
906 | return R; | |||
907 | } | |||
908 | ||||
909 | State() {} | |||
910 | State(const State &SIS) : AccessBins(SIS.AccessBins) {} | |||
911 | State(State &&SIS) : AccessBins(std::move(SIS.AccessBins)) {} | |||
912 | ||||
913 | const State &getAssumed() const { return *this; } | |||
914 | ||||
915 | /// See AbstractState::isValidState(). | |||
916 | bool isValidState() const override { return BS.isValidState(); } | |||
917 | ||||
918 | /// See AbstractState::isAtFixpoint(). | |||
919 | bool isAtFixpoint() const override { return BS.isAtFixpoint(); } | |||
920 | ||||
921 | /// See AbstractState::indicateOptimisticFixpoint(). | |||
922 | ChangeStatus indicateOptimisticFixpoint() override { | |||
923 | BS.indicateOptimisticFixpoint(); | |||
924 | return ChangeStatus::UNCHANGED; | |||
925 | } | |||
926 | ||||
927 | /// See AbstractState::indicatePessimisticFixpoint(). | |||
928 | ChangeStatus indicatePessimisticFixpoint() override { | |||
929 | BS.indicatePessimisticFixpoint(); | |||
930 | return ChangeStatus::CHANGED; | |||
931 | } | |||
932 | ||||
933 | State &operator=(const State &R) { | |||
934 | if (this == &R) | |||
935 | return *this; | |||
936 | BS = R.BS; | |||
937 | AccessBins = R.AccessBins; | |||
938 | return *this; | |||
939 | } | |||
940 | ||||
941 | State &operator=(State &&R) { | |||
942 | if (this == &R) | |||
943 | return *this; | |||
944 | std::swap(BS, R.BS); | |||
945 | std::swap(AccessBins, R.AccessBins); | |||
946 | return *this; | |||
947 | } | |||
948 | ||||
949 | bool operator==(const State &R) const { | |||
950 | if (BS != R.BS) | |||
951 | return false; | |||
952 | if (AccessBins.size() != R.AccessBins.size()) | |||
953 | return false; | |||
954 | auto It = begin(), RIt = R.begin(), E = end(); | |||
955 | while (It != E) { | |||
956 | if (It->getFirst() != RIt->getFirst()) | |||
957 | return false; | |||
958 | auto &Accs = It->getSecond(); | |||
959 | auto &RAccs = RIt->getSecond(); | |||
960 | if (Accs.size() != RAccs.size()) | |||
961 | return false; | |||
962 | auto AccIt = Accs.begin(), RAccIt = RAccs.begin(), AccE = Accs.end(); | |||
963 | while (AccIt != AccE) { | |||
964 | if (*AccIt != *RAccIt) | |||
965 | return false; | |||
966 | ++AccIt; | |||
967 | ++RAccIt; | |||
968 | } | |||
969 | ++It; | |||
970 | ++RIt; | |||
971 | } | |||
972 | return true; | |||
973 | } | |||
974 | bool operator!=(const State &R) const { return !(*this == R); } | |||
975 | ||||
976 | /// We store accesses in a set with the instruction as key. | |||
977 | using Accesses = DenseSet<AAPointerInfo::Access, AccessAsInstructionInfo>; | |||
978 | ||||
979 | /// We store all accesses in bins denoted by their offset and size. | |||
980 | using AccessBinsTy = DenseMap<OffsetAndSize, Accesses>; | |||
981 | ||||
982 | AccessBinsTy::const_iterator begin() const { return AccessBins.begin(); } | |||
983 | AccessBinsTy::const_iterator end() const { return AccessBins.end(); } | |||
984 | ||||
985 | protected: | |||
986 | /// The bins with all the accesses for the associated pointer. | |||
987 | DenseMap<OffsetAndSize, Accesses> AccessBins; | |||
988 | ||||
989 | /// Add a new access to the state at offset \p Offset and with size \p Size. | |||
990 | /// The access is associated with \p I, writes \p Content (if anything), and | |||
991 | /// is of kind \p Kind. | |||
992 | /// \Returns CHANGED, if the state changed, UNCHANGED otherwise. | |||
993 | ChangeStatus addAccess(int64_t Offset, int64_t Size, Instruction &I, | |||
994 | Optional<Value *> Content, | |||
995 | AAPointerInfo::AccessKind Kind, Type *Ty, | |||
996 | Instruction *RemoteI = nullptr, | |||
997 | Accesses *BinPtr = nullptr) { | |||
998 | OffsetAndSize Key{Offset, Size}; | |||
999 | Accesses &Bin = BinPtr ? *BinPtr : AccessBins[Key]; | |||
1000 | AAPointerInfo::Access Acc(&I, RemoteI ? RemoteI : &I, Content, Kind, Ty); | |||
1001 | // Check if we have an access for this instruction in this bin, if not, | |||
1002 | // simply add it. | |||
1003 | auto It = Bin.find(Acc); | |||
1004 | if (It == Bin.end()) { | |||
1005 | Bin.insert(Acc); | |||
1006 | return ChangeStatus::CHANGED; | |||
1007 | } | |||
1008 | // If the existing access is the same as then new one, nothing changed. | |||
1009 | AAPointerInfo::Access Before = *It; | |||
1010 | // The new one will be combined with the existing one. | |||
1011 | *It &= Acc; | |||
1012 | return *It == Before ? ChangeStatus::UNCHANGED : ChangeStatus::CHANGED; | |||
1013 | } | |||
1014 | ||||
1015 | /// See AAPointerInfo::forallInterferingAccesses. | |||
1016 | bool forallInterferingAccesses( | |||
1017 | Instruction &I, | |||
1018 | function_ref<bool(const AAPointerInfo::Access &, bool)> CB) const { | |||
1019 | if (!isValidState()) | |||
1020 | return false; | |||
1021 | // First find the offset and size of I. | |||
1022 | OffsetAndSize OAS(-1, -1); | |||
1023 | for (auto &It : AccessBins) { | |||
1024 | for (auto &Access : It.getSecond()) { | |||
1025 | if (Access.getRemoteInst() == &I) { | |||
1026 | OAS = It.getFirst(); | |||
1027 | break; | |||
1028 | } | |||
1029 | } | |||
1030 | if (OAS.getSize() != -1) | |||
1031 | break; | |||
1032 | } | |||
1033 | if (OAS.getSize() == -1) | |||
1034 | return true; | |||
1035 | ||||
1036 | // Now that we have an offset and size, find all overlapping ones and use | |||
1037 | // the callback on the accesses. | |||
1038 | for (auto &It : AccessBins) { | |||
1039 | OffsetAndSize ItOAS = It.getFirst(); | |||
1040 | if (!OAS.mayOverlap(ItOAS)) | |||
1041 | continue; | |||
1042 | for (auto &Access : It.getSecond()) | |||
1043 | if (!CB(Access, OAS == ItOAS)) | |||
1044 | return false; | |||
1045 | } | |||
1046 | return true; | |||
1047 | } | |||
1048 | ||||
1049 | private: | |||
1050 | /// State to track fixpoint and validity. | |||
1051 | BooleanState BS; | |||
1052 | }; | |||
1053 | ||||
1054 | struct AAPointerInfoImpl | |||
1055 | : public StateWrapper<AA::PointerInfo::State, AAPointerInfo> { | |||
1056 | using BaseTy = StateWrapper<AA::PointerInfo::State, AAPointerInfo>; | |||
1057 | AAPointerInfoImpl(const IRPosition &IRP, Attributor &A) : BaseTy(IRP) {} | |||
1058 | ||||
1059 | /// See AbstractAttribute::initialize(...). | |||
1060 | void initialize(Attributor &A) override { AAPointerInfo::initialize(A); } | |||
1061 | ||||
1062 | /// See AbstractAttribute::getAsStr(). | |||
1063 | const std::string getAsStr() const override { | |||
1064 | return std::string("PointerInfo ") + | |||
1065 | (isValidState() ? (std::string("#") + | |||
1066 | std::to_string(AccessBins.size()) + " bins") | |||
1067 | : "<invalid>"); | |||
1068 | } | |||
1069 | ||||
1070 | /// See AbstractAttribute::manifest(...). | |||
1071 | ChangeStatus manifest(Attributor &A) override { | |||
1072 | return AAPointerInfo::manifest(A); | |||
1073 | } | |||
1074 | ||||
1075 | bool forallInterferingAccesses( | |||
1076 | LoadInst &LI, function_ref<bool(const AAPointerInfo::Access &, bool)> CB) | |||
1077 | const override { | |||
1078 | return State::forallInterferingAccesses(LI, CB); | |||
1079 | } | |||
1080 | bool forallInterferingAccesses( | |||
1081 | StoreInst &SI, function_ref<bool(const AAPointerInfo::Access &, bool)> CB) | |||
1082 | const override { | |||
1083 | return State::forallInterferingAccesses(SI, CB); | |||
1084 | } | |||
1085 | ||||
1086 | ChangeStatus translateAndAddCalleeState(Attributor &A, | |||
1087 | const AAPointerInfo &CalleeAA, | |||
1088 | int64_t CallArgOffset, CallBase &CB) { | |||
1089 | using namespace AA::PointerInfo; | |||
1090 | if (!CalleeAA.getState().isValidState() || !isValidState()) | |||
1091 | return indicatePessimisticFixpoint(); | |||
1092 | ||||
1093 | const auto &CalleeImplAA = static_cast<const AAPointerInfoImpl &>(CalleeAA); | |||
1094 | bool IsByval = CalleeImplAA.getAssociatedArgument()->hasByValAttr(); | |||
1095 | ||||
1096 | // Combine the accesses bin by bin. | |||
1097 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
1098 | for (auto &It : CalleeImplAA.getState()) { | |||
1099 | OffsetAndSize OAS = OffsetAndSize::getUnknown(); | |||
1100 | if (CallArgOffset != OffsetAndSize::Unknown) | |||
1101 | OAS = OffsetAndSize(It.first.getOffset() + CallArgOffset, | |||
1102 | It.first.getSize()); | |||
1103 | Accesses &Bin = AccessBins[OAS]; | |||
1104 | for (const AAPointerInfo::Access &RAcc : It.second) { | |||
1105 | if (IsByval && !RAcc.isRead()) | |||
1106 | continue; | |||
1107 | bool UsedAssumedInformation = false; | |||
1108 | Optional<Value *> Content = A.translateArgumentToCallSiteContent( | |||
1109 | RAcc.getContent(), CB, *this, UsedAssumedInformation); | |||
1110 | AccessKind AK = | |||
1111 | AccessKind(RAcc.getKind() & (IsByval ? AccessKind::AK_READ | |||
1112 | : AccessKind::AK_READ_WRITE)); | |||
1113 | Changed = | |||
1114 | Changed | addAccess(OAS.getOffset(), OAS.getSize(), CB, Content, AK, | |||
1115 | RAcc.getType(), RAcc.getRemoteInst(), &Bin); | |||
1116 | } | |||
1117 | } | |||
1118 | return Changed; | |||
1119 | } | |||
1120 | ||||
1121 | /// Statistic tracking for all AAPointerInfo implementations. | |||
1122 | /// See AbstractAttribute::trackStatistics(). | |||
1123 | void trackPointerInfoStatistics(const IRPosition &IRP) const {} | |||
1124 | }; | |||
1125 | ||||
1126 | struct AAPointerInfoFloating : public AAPointerInfoImpl { | |||
1127 | using AccessKind = AAPointerInfo::AccessKind; | |||
1128 | AAPointerInfoFloating(const IRPosition &IRP, Attributor &A) | |||
1129 | : AAPointerInfoImpl(IRP, A) {} | |||
1130 | ||||
1131 | /// See AbstractAttribute::initialize(...). | |||
1132 | void initialize(Attributor &A) override { AAPointerInfoImpl::initialize(A); } | |||
1133 | ||||
1134 | /// Deal with an access and signal if it was handled successfully. | |||
1135 | bool handleAccess(Attributor &A, Instruction &I, Value &Ptr, | |||
1136 | Optional<Value *> Content, AccessKind Kind, int64_t Offset, | |||
1137 | ChangeStatus &Changed, Type *Ty, | |||
1138 | int64_t Size = AA::PointerInfo::OffsetAndSize::Unknown) { | |||
1139 | using namespace AA::PointerInfo; | |||
1140 | // No need to find a size if one is given or the offset is unknown. | |||
1141 | if (Offset != OffsetAndSize::Unknown && Size == OffsetAndSize::Unknown && | |||
1142 | Ty) { | |||
1143 | const DataLayout &DL = A.getDataLayout(); | |||
1144 | TypeSize AccessSize = DL.getTypeStoreSize(Ty); | |||
1145 | if (!AccessSize.isScalable()) | |||
1146 | Size = AccessSize.getFixedSize(); | |||
1147 | } | |||
1148 | Changed = Changed | addAccess(Offset, Size, I, Content, Kind, Ty); | |||
1149 | return true; | |||
1150 | }; | |||
1151 | ||||
1152 | /// Helper struct, will support ranges eventually. | |||
1153 | struct OffsetInfo { | |||
1154 | int64_t Offset = AA::PointerInfo::OffsetAndSize::Unknown; | |||
1155 | ||||
1156 | bool operator==(const OffsetInfo &OI) const { return Offset == OI.Offset; } | |||
1157 | }; | |||
1158 | ||||
1159 | /// See AbstractAttribute::updateImpl(...). | |||
1160 | ChangeStatus updateImpl(Attributor &A) override { | |||
1161 | using namespace AA::PointerInfo; | |||
1162 | State S = getState(); | |||
1163 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
1164 | Value &AssociatedValue = getAssociatedValue(); | |||
1165 | ||||
1166 | const DataLayout &DL = A.getDataLayout(); | |||
1167 | DenseMap<Value *, OffsetInfo> OffsetInfoMap; | |||
1168 | OffsetInfoMap[&AssociatedValue] = OffsetInfo{0}; | |||
1169 | ||||
1170 | auto HandlePassthroughUser = [&](Value *Usr, OffsetInfo &PtrOI, | |||
1171 | bool &Follow) { | |||
1172 | OffsetInfo &UsrOI = OffsetInfoMap[Usr]; | |||
1173 | UsrOI = PtrOI; | |||
1174 | Follow = true; | |||
1175 | return true; | |||
1176 | }; | |||
1177 | ||||
1178 | auto UsePred = [&](const Use &U, bool &Follow) -> bool { | |||
1179 | Value *CurPtr = U.get(); | |||
1180 | User *Usr = U.getUser(); | |||
1181 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Analyze " << *CurPtr << " in "do { } while (false) | |||
1182 | << *Usr << "\n")do { } while (false); | |||
1183 | ||||
1184 | OffsetInfo &PtrOI = OffsetInfoMap[CurPtr]; | |||
1185 | ||||
1186 | if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Usr)) { | |||
1187 | if (CE->isCast()) | |||
1188 | return HandlePassthroughUser(Usr, PtrOI, Follow); | |||
1189 | if (CE->isCompare()) | |||
1190 | return true; | |||
1191 | if (!CE->isGEPWithNoNotionalOverIndexing()) { | |||
1192 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Unhandled constant user " << *CEdo { } while (false) | |||
1193 | << "\n")do { } while (false); | |||
1194 | return false; | |||
1195 | } | |||
1196 | } | |||
1197 | if (auto *GEP = dyn_cast<GEPOperator>(Usr)) { | |||
1198 | OffsetInfo &UsrOI = OffsetInfoMap[Usr]; | |||
1199 | UsrOI = PtrOI; | |||
1200 | ||||
1201 | // TODO: Use range information. | |||
1202 | if (PtrOI.Offset == OffsetAndSize::Unknown || | |||
1203 | !GEP->hasAllConstantIndices()) { | |||
1204 | UsrOI.Offset = OffsetAndSize::Unknown; | |||
1205 | Follow = true; | |||
1206 | return true; | |||
1207 | } | |||
1208 | ||||
1209 | SmallVector<Value *, 8> Indices; | |||
1210 | for (Use &Idx : llvm::make_range(GEP->idx_begin(), GEP->idx_end())) { | |||
1211 | if (auto *CIdx = dyn_cast<ConstantInt>(Idx)) { | |||
1212 | Indices.push_back(CIdx); | |||
1213 | continue; | |||
1214 | } | |||
1215 | ||||
1216 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Non constant GEP index " << *GEPdo { } while (false) | |||
1217 | << " : " << *Idx << "\n")do { } while (false); | |||
1218 | return false; | |||
1219 | } | |||
1220 | UsrOI.Offset = PtrOI.Offset + | |||
1221 | DL.getIndexedOffsetInType( | |||
1222 | CurPtr->getType()->getPointerElementType(), Indices); | |||
1223 | Follow = true; | |||
1224 | return true; | |||
1225 | } | |||
1226 | if (isa<CastInst>(Usr) || isa<SelectInst>(Usr)) | |||
1227 | return HandlePassthroughUser(Usr, PtrOI, Follow); | |||
1228 | ||||
1229 | // For PHIs we need to take care of the recurrence explicitly as the value | |||
1230 | // might change while we iterate through a loop. For now, we give up if | |||
1231 | // the PHI is not invariant. | |||
1232 | if (isa<PHINode>(Usr)) { | |||
1233 | // Check if the PHI is invariant (so far). | |||
1234 | OffsetInfo &UsrOI = OffsetInfoMap[Usr]; | |||
1235 | if (UsrOI == PtrOI) | |||
1236 | return true; | |||
1237 | ||||
1238 | // Check if the PHI operand has already an unknown offset as we can't | |||
1239 | // improve on that anymore. | |||
1240 | if (PtrOI.Offset == OffsetAndSize::Unknown) { | |||
1241 | UsrOI = PtrOI; | |||
1242 | Follow = true; | |||
1243 | return true; | |||
1244 | } | |||
1245 | ||||
1246 | // Check if the PHI operand is not dependent on the PHI itself. | |||
1247 | APInt Offset(DL.getIndexTypeSizeInBits(AssociatedValue.getType()), 0); | |||
1248 | if (&AssociatedValue == CurPtr->stripAndAccumulateConstantOffsets( | |||
1249 | DL, Offset, /* AllowNonInbounds */ true)) { | |||
1250 | if (Offset != PtrOI.Offset) { | |||
1251 | LLVM_DEBUG(dbgs()do { } while (false) | |||
1252 | << "[AAPointerInfo] PHI operand pointer offset mismatch "do { } while (false) | |||
1253 | << *CurPtr << " in " << *Usr << "\n")do { } while (false); | |||
1254 | return false; | |||
1255 | } | |||
1256 | return HandlePassthroughUser(Usr, PtrOI, Follow); | |||
1257 | } | |||
1258 | ||||
1259 | // TODO: Approximate in case we know the direction of the recurrence. | |||
1260 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] PHI operand is too complex "do { } while (false) | |||
1261 | << *CurPtr << " in " << *Usr << "\n")do { } while (false); | |||
1262 | UsrOI = PtrOI; | |||
1263 | UsrOI.Offset = OffsetAndSize::Unknown; | |||
1264 | Follow = true; | |||
1265 | return true; | |||
1266 | } | |||
1267 | ||||
1268 | if (auto *LoadI = dyn_cast<LoadInst>(Usr)) | |||
1269 | return handleAccess(A, *LoadI, *CurPtr, /* Content */ nullptr, | |||
1270 | AccessKind::AK_READ, PtrOI.Offset, Changed, | |||
1271 | LoadI->getType()); | |||
1272 | if (auto *StoreI = dyn_cast<StoreInst>(Usr)) { | |||
1273 | if (StoreI->getValueOperand() == CurPtr) { | |||
1274 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Escaping use in store "do { } while (false) | |||
1275 | << *StoreI << "\n")do { } while (false); | |||
1276 | return false; | |||
1277 | } | |||
1278 | bool UsedAssumedInformation = false; | |||
1279 | Optional<Value *> Content = A.getAssumedSimplified( | |||
1280 | *StoreI->getValueOperand(), *this, UsedAssumedInformation); | |||
1281 | return handleAccess(A, *StoreI, *CurPtr, Content, AccessKind::AK_WRITE, | |||
1282 | PtrOI.Offset, Changed, | |||
1283 | StoreI->getValueOperand()->getType()); | |||
1284 | } | |||
1285 | if (auto *CB = dyn_cast<CallBase>(Usr)) { | |||
1286 | if (CB->isLifetimeStartOrEnd()) | |||
1287 | return true; | |||
1288 | if (CB->isArgOperand(&U)) { | |||
1289 | unsigned ArgNo = CB->getArgOperandNo(&U); | |||
1290 | const auto &CSArgPI = A.getAAFor<AAPointerInfo>( | |||
1291 | *this, IRPosition::callsite_argument(*CB, ArgNo), | |||
1292 | DepClassTy::REQUIRED); | |||
1293 | Changed = translateAndAddCalleeState(A, CSArgPI, PtrOI.Offset, *CB) | | |||
1294 | Changed; | |||
1295 | return true; | |||
1296 | } | |||
1297 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Call user not handled " << *CBdo { } while (false) | |||
1298 | << "\n")do { } while (false); | |||
1299 | // TODO: Allow some call uses | |||
1300 | return false; | |||
1301 | } | |||
1302 | ||||
1303 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] User not handled " << *Usr << "\n")do { } while (false); | |||
1304 | return false; | |||
1305 | }; | |||
1306 | if (!A.checkForAllUses(UsePred, *this, AssociatedValue, | |||
1307 | /* CheckBBLivenessOnly */ true)) | |||
1308 | return indicatePessimisticFixpoint(); | |||
1309 | ||||
1310 | LLVM_DEBUG({do { } while (false) | |||
1311 | dbgs() << "Accesses by bin after update:\n";do { } while (false) | |||
1312 | for (auto &It : AccessBins) {do { } while (false) | |||
1313 | dbgs() << "[" << It.first.getOffset() << "-"do { } while (false) | |||
1314 | << It.first.getOffset() + It.first.getSize()do { } while (false) | |||
1315 | << "] : " << It.getSecond().size() << "\n";do { } while (false) | |||
1316 | for (auto &Acc : It.getSecond()) {do { } while (false) | |||
1317 | dbgs() << " - " << Acc.getKind() << " - " << *Acc.getLocalInst()do { } while (false) | |||
1318 | << "\n";do { } while (false) | |||
1319 | if (Acc.getLocalInst() != Acc.getRemoteInst())do { } while (false) | |||
1320 | dbgs() << " --> "do { } while (false) | |||
1321 | << *Acc.getRemoteInst() << "\n";do { } while (false) | |||
1322 | if (!Acc.isWrittenValueYetUndetermined())do { } while (false) | |||
1323 | dbgs() << " - " << Acc.getWrittenValue() << "\n";do { } while (false) | |||
1324 | }do { } while (false) | |||
1325 | }do { } while (false) | |||
1326 | })do { } while (false); | |||
1327 | ||||
1328 | return Changed; | |||
1329 | } | |||
1330 | ||||
1331 | /// See AbstractAttribute::trackStatistics() | |||
1332 | void trackStatistics() const override { | |||
1333 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); | |||
1334 | } | |||
1335 | }; | |||
1336 | ||||
1337 | struct AAPointerInfoReturned final : AAPointerInfoImpl { | |||
1338 | AAPointerInfoReturned(const IRPosition &IRP, Attributor &A) | |||
1339 | : AAPointerInfoImpl(IRP, A) {} | |||
1340 | ||||
1341 | /// See AbstractAttribute::updateImpl(...). | |||
1342 | ChangeStatus updateImpl(Attributor &A) override { | |||
1343 | return indicatePessimisticFixpoint(); | |||
1344 | } | |||
1345 | ||||
1346 | /// See AbstractAttribute::trackStatistics() | |||
1347 | void trackStatistics() const override { | |||
1348 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); | |||
1349 | } | |||
1350 | }; | |||
1351 | ||||
1352 | struct AAPointerInfoArgument final : AAPointerInfoFloating { | |||
1353 | AAPointerInfoArgument(const IRPosition &IRP, Attributor &A) | |||
1354 | : AAPointerInfoFloating(IRP, A) {} | |||
1355 | ||||
1356 | /// See AbstractAttribute::initialize(...). | |||
1357 | void initialize(Attributor &A) override { | |||
1358 | AAPointerInfoFloating::initialize(A); | |||
1359 | if (getAnchorScope()->isDeclaration()) | |||
1360 | indicatePessimisticFixpoint(); | |||
1361 | } | |||
1362 | ||||
1363 | /// See AbstractAttribute::trackStatistics() | |||
1364 | void trackStatistics() const override { | |||
1365 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); | |||
1366 | } | |||
1367 | }; | |||
1368 | ||||
1369 | struct AAPointerInfoCallSiteArgument final : AAPointerInfoFloating { | |||
1370 | AAPointerInfoCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
1371 | : AAPointerInfoFloating(IRP, A) {} | |||
1372 | ||||
1373 | /// See AbstractAttribute::updateImpl(...). | |||
1374 | ChangeStatus updateImpl(Attributor &A) override { | |||
1375 | using namespace AA::PointerInfo; | |||
1376 | // We handle memory intrinsics explicitly, at least the first (= | |||
1377 | // destination) and second (=source) arguments as we know how they are | |||
1378 | // accessed. | |||
1379 | if (auto *MI = dyn_cast_or_null<MemIntrinsic>(getCtxI())) { | |||
1380 | ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); | |||
1381 | int64_t LengthVal = OffsetAndSize::Unknown; | |||
1382 | if (Length) | |||
1383 | LengthVal = Length->getSExtValue(); | |||
1384 | Value &Ptr = getAssociatedValue(); | |||
1385 | unsigned ArgNo = getIRPosition().getCallSiteArgNo(); | |||
1386 | ChangeStatus Changed; | |||
1387 | if (ArgNo == 0) { | |||
1388 | handleAccess(A, *MI, Ptr, nullptr, AccessKind::AK_WRITE, 0, Changed, | |||
1389 | nullptr, LengthVal); | |||
1390 | } else if (ArgNo == 1) { | |||
1391 | handleAccess(A, *MI, Ptr, nullptr, AccessKind::AK_READ, 0, Changed, | |||
1392 | nullptr, LengthVal); | |||
1393 | } else { | |||
1394 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Unhandled memory intrinsic "do { } while (false) | |||
1395 | << *MI << "\n")do { } while (false); | |||
1396 | return indicatePessimisticFixpoint(); | |||
1397 | } | |||
1398 | return Changed; | |||
1399 | } | |||
1400 | ||||
1401 | // TODO: Once we have call site specific value information we can provide | |||
1402 | // call site specific liveness information and then it makes | |||
1403 | // sense to specialize attributes for call sites arguments instead of | |||
1404 | // redirecting requests to the callee argument. | |||
1405 | Argument *Arg = getAssociatedArgument(); | |||
1406 | if (!Arg) | |||
1407 | return indicatePessimisticFixpoint(); | |||
1408 | const IRPosition &ArgPos = IRPosition::argument(*Arg); | |||
1409 | auto &ArgAA = | |||
1410 | A.getAAFor<AAPointerInfo>(*this, ArgPos, DepClassTy::REQUIRED); | |||
1411 | return translateAndAddCalleeState(A, ArgAA, 0, *cast<CallBase>(getCtxI())); | |||
1412 | } | |||
1413 | ||||
1414 | /// See AbstractAttribute::trackStatistics() | |||
1415 | void trackStatistics() const override { | |||
1416 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); | |||
1417 | } | |||
1418 | }; | |||
1419 | ||||
1420 | struct AAPointerInfoCallSiteReturned final : AAPointerInfoFloating { | |||
1421 | AAPointerInfoCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
1422 | : AAPointerInfoFloating(IRP, A) {} | |||
1423 | ||||
1424 | /// See AbstractAttribute::trackStatistics() | |||
1425 | void trackStatistics() const override { | |||
1426 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); | |||
1427 | } | |||
1428 | }; | |||
1429 | ||||
1430 | /// -----------------------NoUnwind Function Attribute-------------------------- | |||
1431 | ||||
1432 | struct AANoUnwindImpl : AANoUnwind { | |||
1433 | AANoUnwindImpl(const IRPosition &IRP, Attributor &A) : AANoUnwind(IRP, A) {} | |||
1434 | ||||
1435 | const std::string getAsStr() const override { | |||
1436 | return getAssumed() ? "nounwind" : "may-unwind"; | |||
1437 | } | |||
1438 | ||||
1439 | /// See AbstractAttribute::updateImpl(...). | |||
1440 | ChangeStatus updateImpl(Attributor &A) override { | |||
1441 | auto Opcodes = { | |||
1442 | (unsigned)Instruction::Invoke, (unsigned)Instruction::CallBr, | |||
1443 | (unsigned)Instruction::Call, (unsigned)Instruction::CleanupRet, | |||
1444 | (unsigned)Instruction::CatchSwitch, (unsigned)Instruction::Resume}; | |||
1445 | ||||
1446 | auto CheckForNoUnwind = [&](Instruction &I) { | |||
1447 | if (!I.mayThrow()) | |||
1448 | return true; | |||
1449 | ||||
1450 | if (const auto *CB = dyn_cast<CallBase>(&I)) { | |||
1451 | const auto &NoUnwindAA = A.getAAFor<AANoUnwind>( | |||
1452 | *this, IRPosition::callsite_function(*CB), DepClassTy::REQUIRED); | |||
1453 | return NoUnwindAA.isAssumedNoUnwind(); | |||
1454 | } | |||
1455 | return false; | |||
1456 | }; | |||
1457 | ||||
1458 | bool UsedAssumedInformation = false; | |||
1459 | if (!A.checkForAllInstructions(CheckForNoUnwind, *this, Opcodes, | |||
1460 | UsedAssumedInformation)) | |||
1461 | return indicatePessimisticFixpoint(); | |||
1462 | ||||
1463 | return ChangeStatus::UNCHANGED; | |||
1464 | } | |||
1465 | }; | |||
1466 | ||||
1467 | struct AANoUnwindFunction final : public AANoUnwindImpl { | |||
1468 | AANoUnwindFunction(const IRPosition &IRP, Attributor &A) | |||
1469 | : AANoUnwindImpl(IRP, A) {} | |||
1470 | ||||
1471 | /// See AbstractAttribute::trackStatistics() | |||
1472 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(nounwind){ static llvm::Statistic NumIRFunction_nounwind = {"attributor" , "NumIRFunction_nounwind", ("Number of " "functions" " marked '" "nounwind" "'")};; ++(NumIRFunction_nounwind); } } | |||
1473 | }; | |||
1474 | ||||
1475 | /// NoUnwind attribute deduction for a call sites. | |||
1476 | struct AANoUnwindCallSite final : AANoUnwindImpl { | |||
1477 | AANoUnwindCallSite(const IRPosition &IRP, Attributor &A) | |||
1478 | : AANoUnwindImpl(IRP, A) {} | |||
1479 | ||||
1480 | /// See AbstractAttribute::initialize(...). | |||
1481 | void initialize(Attributor &A) override { | |||
1482 | AANoUnwindImpl::initialize(A); | |||
1483 | Function *F = getAssociatedFunction(); | |||
1484 | if (!F || F->isDeclaration()) | |||
1485 | indicatePessimisticFixpoint(); | |||
1486 | } | |||
1487 | ||||
1488 | /// See AbstractAttribute::updateImpl(...). | |||
1489 | ChangeStatus updateImpl(Attributor &A) override { | |||
1490 | // TODO: Once we have call site specific value information we can provide | |||
1491 | // call site specific liveness information and then it makes | |||
1492 | // sense to specialize attributes for call sites arguments instead of | |||
1493 | // redirecting requests to the callee argument. | |||
1494 | Function *F = getAssociatedFunction(); | |||
1495 | const IRPosition &FnPos = IRPosition::function(*F); | |||
1496 | auto &FnAA = A.getAAFor<AANoUnwind>(*this, FnPos, DepClassTy::REQUIRED); | |||
1497 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
1498 | } | |||
1499 | ||||
1500 | /// See AbstractAttribute::trackStatistics() | |||
1501 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(nounwind){ static llvm::Statistic NumIRCS_nounwind = {"attributor", "NumIRCS_nounwind" , ("Number of " "call site" " marked '" "nounwind" "'")};; ++ (NumIRCS_nounwind); }; } | |||
1502 | }; | |||
1503 | ||||
1504 | /// --------------------- Function Return Values ------------------------------- | |||
1505 | ||||
1506 | /// "Attribute" that collects all potential returned values and the return | |||
1507 | /// instructions that they arise from. | |||
1508 | /// | |||
1509 | /// If there is a unique returned value R, the manifest method will: | |||
1510 | /// - mark R with the "returned" attribute, if R is an argument. | |||
1511 | class AAReturnedValuesImpl : public AAReturnedValues, public AbstractState { | |||
1512 | ||||
1513 | /// Mapping of values potentially returned by the associated function to the | |||
1514 | /// return instructions that might return them. | |||
1515 | MapVector<Value *, SmallSetVector<ReturnInst *, 4>> ReturnedValues; | |||
1516 | ||||
1517 | /// State flags | |||
1518 | /// | |||
1519 | ///{ | |||
1520 | bool IsFixed = false; | |||
1521 | bool IsValidState = true; | |||
1522 | ///} | |||
1523 | ||||
1524 | public: | |||
1525 | AAReturnedValuesImpl(const IRPosition &IRP, Attributor &A) | |||
1526 | : AAReturnedValues(IRP, A) {} | |||
1527 | ||||
1528 | /// See AbstractAttribute::initialize(...). | |||
1529 | void initialize(Attributor &A) override { | |||
1530 | // Reset the state. | |||
1531 | IsFixed = false; | |||
1532 | IsValidState = true; | |||
1533 | ReturnedValues.clear(); | |||
1534 | ||||
1535 | Function *F = getAssociatedFunction(); | |||
1536 | if (!F || F->isDeclaration()) { | |||
1537 | indicatePessimisticFixpoint(); | |||
1538 | return; | |||
1539 | } | |||
1540 | assert(!F->getReturnType()->isVoidTy() &&((void)0) | |||
1541 | "Did not expect a void return type!")((void)0); | |||
1542 | ||||
1543 | // The map from instruction opcodes to those instructions in the function. | |||
1544 | auto &OpcodeInstMap = A.getInfoCache().getOpcodeInstMapForFunction(*F); | |||
1545 | ||||
1546 | // Look through all arguments, if one is marked as returned we are done. | |||
1547 | for (Argument &Arg : F->args()) { | |||
1548 | if (Arg.hasReturnedAttr()) { | |||
1549 | auto &ReturnInstSet = ReturnedValues[&Arg]; | |||
1550 | if (auto *Insts = OpcodeInstMap.lookup(Instruction::Ret)) | |||
1551 | for (Instruction *RI : *Insts) | |||
1552 | ReturnInstSet.insert(cast<ReturnInst>(RI)); | |||
1553 | ||||
1554 | indicateOptimisticFixpoint(); | |||
1555 | return; | |||
1556 | } | |||
1557 | } | |||
1558 | ||||
1559 | if (!A.isFunctionIPOAmendable(*F)) | |||
1560 | indicatePessimisticFixpoint(); | |||
1561 | } | |||
1562 | ||||
1563 | /// See AbstractAttribute::manifest(...). | |||
1564 | ChangeStatus manifest(Attributor &A) override; | |||
1565 | ||||
1566 | /// See AbstractAttribute::getState(...). | |||
1567 | AbstractState &getState() override { return *this; } | |||
1568 | ||||
1569 | /// See AbstractAttribute::getState(...). | |||
1570 | const AbstractState &getState() const override { return *this; } | |||
1571 | ||||
1572 | /// See AbstractAttribute::updateImpl(Attributor &A). | |||
1573 | ChangeStatus updateImpl(Attributor &A) override; | |||
1574 | ||||
1575 | llvm::iterator_range<iterator> returned_values() override { | |||
1576 | return llvm::make_range(ReturnedValues.begin(), ReturnedValues.end()); | |||
1577 | } | |||
1578 | ||||
1579 | llvm::iterator_range<const_iterator> returned_values() const override { | |||
1580 | return llvm::make_range(ReturnedValues.begin(), ReturnedValues.end()); | |||
1581 | } | |||
1582 | ||||
1583 | /// Return the number of potential return values, -1 if unknown. | |||
1584 | size_t getNumReturnValues() const override { | |||
1585 | return isValidState() ? ReturnedValues.size() : -1; | |||
1586 | } | |||
1587 | ||||
1588 | /// Return an assumed unique return value if a single candidate is found. If | |||
1589 | /// there cannot be one, return a nullptr. If it is not clear yet, return the | |||
1590 | /// Optional::NoneType. | |||
1591 | Optional<Value *> getAssumedUniqueReturnValue(Attributor &A) const; | |||
1592 | ||||
1593 | /// See AbstractState::checkForAllReturnedValues(...). | |||
1594 | bool checkForAllReturnedValuesAndReturnInsts( | |||
1595 | function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred) | |||
1596 | const override; | |||
1597 | ||||
1598 | /// Pretty print the attribute similar to the IR representation. | |||
1599 | const std::string getAsStr() const override; | |||
1600 | ||||
1601 | /// See AbstractState::isAtFixpoint(). | |||
1602 | bool isAtFixpoint() const override { return IsFixed; } | |||
1603 | ||||
1604 | /// See AbstractState::isValidState(). | |||
1605 | bool isValidState() const override { return IsValidState; } | |||
1606 | ||||
1607 | /// See AbstractState::indicateOptimisticFixpoint(...). | |||
1608 | ChangeStatus indicateOptimisticFixpoint() override { | |||
1609 | IsFixed = true; | |||
1610 | return ChangeStatus::UNCHANGED; | |||
1611 | } | |||
1612 | ||||
1613 | ChangeStatus indicatePessimisticFixpoint() override { | |||
1614 | IsFixed = true; | |||
1615 | IsValidState = false; | |||
1616 | return ChangeStatus::CHANGED; | |||
1617 | } | |||
1618 | }; | |||
1619 | ||||
1620 | ChangeStatus AAReturnedValuesImpl::manifest(Attributor &A) { | |||
1621 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
1622 | ||||
1623 | // Bookkeeping. | |||
1624 | assert(isValidState())((void)0); | |||
1625 | STATS_DECLTRACK(KnownReturnValues, FunctionReturn,{ static llvm::Statistic NumIRFunctionReturn_KnownReturnValues = {"attributor", "NumIRFunctionReturn_KnownReturnValues", "Number of function with known return values" };; ++(NumIRFunctionReturn_KnownReturnValues); } | |||
1626 | "Number of function with known return values"){ static llvm::Statistic NumIRFunctionReturn_KnownReturnValues = {"attributor", "NumIRFunctionReturn_KnownReturnValues", "Number of function with known return values" };; ++(NumIRFunctionReturn_KnownReturnValues); }; | |||
1627 | ||||
1628 | // Check if we have an assumed unique return value that we could manifest. | |||
1629 | Optional<Value *> UniqueRV = getAssumedUniqueReturnValue(A); | |||
1630 | ||||
1631 | if (!UniqueRV.hasValue() || !UniqueRV.getValue()) | |||
1632 | return Changed; | |||
1633 | ||||
1634 | // Bookkeeping. | |||
1635 | STATS_DECLTRACK(UniqueReturnValue, FunctionReturn,{ static llvm::Statistic NumIRFunctionReturn_UniqueReturnValue = {"attributor", "NumIRFunctionReturn_UniqueReturnValue", "Number of function with unique return" };; ++(NumIRFunctionReturn_UniqueReturnValue); } | |||
1636 | "Number of function with unique return"){ static llvm::Statistic NumIRFunctionReturn_UniqueReturnValue = {"attributor", "NumIRFunctionReturn_UniqueReturnValue", "Number of function with unique return" };; ++(NumIRFunctionReturn_UniqueReturnValue); }; | |||
1637 | // If the assumed unique return value is an argument, annotate it. | |||
1638 | if (auto *UniqueRVArg = dyn_cast<Argument>(UniqueRV.getValue())) { | |||
1639 | if (UniqueRVArg->getType()->canLosslesslyBitCastTo( | |||
1640 | getAssociatedFunction()->getReturnType())) { | |||
1641 | getIRPosition() = IRPosition::argument(*UniqueRVArg); | |||
1642 | Changed = IRAttribute::manifest(A); | |||
1643 | } | |||
1644 | } | |||
1645 | return Changed; | |||
1646 | } | |||
1647 | ||||
1648 | const std::string AAReturnedValuesImpl::getAsStr() const { | |||
1649 | return (isAtFixpoint() ? "returns(#" : "may-return(#") + | |||
1650 | (isValidState() ? std::to_string(getNumReturnValues()) : "?") + ")"; | |||
1651 | } | |||
1652 | ||||
1653 | Optional<Value *> | |||
1654 | AAReturnedValuesImpl::getAssumedUniqueReturnValue(Attributor &A) const { | |||
1655 | // If checkForAllReturnedValues provides a unique value, ignoring potential | |||
1656 | // undef values that can also be present, it is assumed to be the actual | |||
1657 | // return value and forwarded to the caller of this method. If there are | |||
1658 | // multiple, a nullptr is returned indicating there cannot be a unique | |||
1659 | // returned value. | |||
1660 | Optional<Value *> UniqueRV; | |||
1661 | Type *Ty = getAssociatedFunction()->getReturnType(); | |||
1662 | ||||
1663 | auto Pred = [&](Value &RV) -> bool { | |||
1664 | UniqueRV = AA::combineOptionalValuesInAAValueLatice(UniqueRV, &RV, Ty); | |||
1665 | return UniqueRV != Optional<Value *>(nullptr); | |||
1666 | }; | |||
1667 | ||||
1668 | if (!A.checkForAllReturnedValues(Pred, *this)) | |||
1669 | UniqueRV = nullptr; | |||
1670 | ||||
1671 | return UniqueRV; | |||
1672 | } | |||
1673 | ||||
1674 | bool AAReturnedValuesImpl::checkForAllReturnedValuesAndReturnInsts( | |||
1675 | function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred) | |||
1676 | const { | |||
1677 | if (!isValidState()) | |||
1678 | return false; | |||
1679 | ||||
1680 | // Check all returned values but ignore call sites as long as we have not | |||
1681 | // encountered an overdefined one during an update. | |||
1682 | for (auto &It : ReturnedValues) { | |||
1683 | Value *RV = It.first; | |||
1684 | if (!Pred(*RV, It.second)) | |||
1685 | return false; | |||
1686 | } | |||
1687 | ||||
1688 | return true; | |||
1689 | } | |||
1690 | ||||
1691 | ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) { | |||
1692 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
1693 | ||||
1694 | auto ReturnValueCB = [&](Value &V, const Instruction *CtxI, ReturnInst &Ret, | |||
1695 | bool) -> bool { | |||
1696 | bool UsedAssumedInformation = false; | |||
1697 | Optional<Value *> SimpleRetVal = | |||
1698 | A.getAssumedSimplified(V, *this, UsedAssumedInformation); | |||
1699 | if (!SimpleRetVal.hasValue()) | |||
1700 | return true; | |||
1701 | if (!SimpleRetVal.getValue()) | |||
1702 | return false; | |||
1703 | Value *RetVal = *SimpleRetVal; | |||
1704 | assert(AA::isValidInScope(*RetVal, Ret.getFunction()) &&((void)0) | |||
1705 | "Assumed returned value should be valid in function scope!")((void)0); | |||
1706 | if (ReturnedValues[RetVal].insert(&Ret)) | |||
1707 | Changed = ChangeStatus::CHANGED; | |||
1708 | return true; | |||
1709 | }; | |||
1710 | ||||
1711 | auto ReturnInstCB = [&](Instruction &I) { | |||
1712 | ReturnInst &Ret = cast<ReturnInst>(I); | |||
1713 | return genericValueTraversal<ReturnInst>( | |||
1714 | A, IRPosition::value(*Ret.getReturnValue()), *this, Ret, ReturnValueCB, | |||
1715 | &I); | |||
1716 | }; | |||
1717 | ||||
1718 | // Discover returned values from all live returned instructions in the | |||
1719 | // associated function. | |||
1720 | bool UsedAssumedInformation = false; | |||
1721 | if (!A.checkForAllInstructions(ReturnInstCB, *this, {Instruction::Ret}, | |||
1722 | UsedAssumedInformation)) | |||
1723 | return indicatePessimisticFixpoint(); | |||
1724 | return Changed; | |||
1725 | } | |||
1726 | ||||
1727 | struct AAReturnedValuesFunction final : public AAReturnedValuesImpl { | |||
1728 | AAReturnedValuesFunction(const IRPosition &IRP, Attributor &A) | |||
1729 | : AAReturnedValuesImpl(IRP, A) {} | |||
1730 | ||||
1731 | /// See AbstractAttribute::trackStatistics() | |||
1732 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(returned){ static llvm::Statistic NumIRArguments_returned = {"attributor" , "NumIRArguments_returned", ("Number of " "arguments" " marked '" "returned" "'")};; ++(NumIRArguments_returned); } } | |||
1733 | }; | |||
1734 | ||||
1735 | /// Returned values information for a call sites. | |||
1736 | struct AAReturnedValuesCallSite final : AAReturnedValuesImpl { | |||
1737 | AAReturnedValuesCallSite(const IRPosition &IRP, Attributor &A) | |||
1738 | : AAReturnedValuesImpl(IRP, A) {} | |||
1739 | ||||
1740 | /// See AbstractAttribute::initialize(...). | |||
1741 | void initialize(Attributor &A) override { | |||
1742 | // TODO: Once we have call site specific value information we can provide | |||
1743 | // call site specific liveness information and then it makes | |||
1744 | // sense to specialize attributes for call sites instead of | |||
1745 | // redirecting requests to the callee. | |||
1746 | llvm_unreachable("Abstract attributes for returned values are not "__builtin_unreachable() | |||
1747 | "supported for call sites yet!")__builtin_unreachable(); | |||
1748 | } | |||
1749 | ||||
1750 | /// See AbstractAttribute::updateImpl(...). | |||
1751 | ChangeStatus updateImpl(Attributor &A) override { | |||
1752 | return indicatePessimisticFixpoint(); | |||
1753 | } | |||
1754 | ||||
1755 | /// See AbstractAttribute::trackStatistics() | |||
1756 | void trackStatistics() const override {} | |||
1757 | }; | |||
1758 | ||||
1759 | /// ------------------------ NoSync Function Attribute ------------------------- | |||
1760 | ||||
1761 | struct AANoSyncImpl : AANoSync { | |||
1762 | AANoSyncImpl(const IRPosition &IRP, Attributor &A) : AANoSync(IRP, A) {} | |||
1763 | ||||
1764 | const std::string getAsStr() const override { | |||
1765 | return getAssumed() ? "nosync" : "may-sync"; | |||
1766 | } | |||
1767 | ||||
1768 | /// See AbstractAttribute::updateImpl(...). | |||
1769 | ChangeStatus updateImpl(Attributor &A) override; | |||
1770 | ||||
1771 | /// Helper function used to determine whether an instruction is non-relaxed | |||
1772 | /// atomic. In other words, if an atomic instruction does not have unordered | |||
1773 | /// or monotonic ordering | |||
1774 | static bool isNonRelaxedAtomic(Instruction *I); | |||
1775 | ||||
1776 | /// Helper function specific for intrinsics which are potentially volatile | |||
1777 | static bool isNoSyncIntrinsic(Instruction *I); | |||
1778 | }; | |||
1779 | ||||
1780 | bool AANoSyncImpl::isNonRelaxedAtomic(Instruction *I) { | |||
1781 | if (!I->isAtomic()) | |||
1782 | return false; | |||
1783 | ||||
1784 | if (auto *FI = dyn_cast<FenceInst>(I)) | |||
1785 | // All legal orderings for fence are stronger than monotonic. | |||
1786 | return FI->getSyncScopeID() != SyncScope::SingleThread; | |||
1787 | else if (auto *AI = dyn_cast<AtomicCmpXchgInst>(I)) { | |||
1788 | // Unordered is not a legal ordering for cmpxchg. | |||
1789 | return (AI->getSuccessOrdering() != AtomicOrdering::Monotonic || | |||
1790 | AI->getFailureOrdering() != AtomicOrdering::Monotonic); | |||
1791 | } | |||
1792 | ||||
1793 | AtomicOrdering Ordering; | |||
1794 | switch (I->getOpcode()) { | |||
1795 | case Instruction::AtomicRMW: | |||
1796 | Ordering = cast<AtomicRMWInst>(I)->getOrdering(); | |||
1797 | break; | |||
1798 | case Instruction::Store: | |||
1799 | Ordering = cast<StoreInst>(I)->getOrdering(); | |||
1800 | break; | |||
1801 | case Instruction::Load: | |||
1802 | Ordering = cast<LoadInst>(I)->getOrdering(); | |||
1803 | break; | |||
1804 | default: | |||
1805 | llvm_unreachable(__builtin_unreachable() | |||
1806 | "New atomic operations need to be known in the attributor.")__builtin_unreachable(); | |||
1807 | } | |||
1808 | ||||
1809 | return (Ordering != AtomicOrdering::Unordered && | |||
1810 | Ordering != AtomicOrdering::Monotonic); | |||
1811 | } | |||
1812 | ||||
1813 | /// Return true if this intrinsic is nosync. This is only used for intrinsics | |||
1814 | /// which would be nosync except that they have a volatile flag. All other | |||
1815 | /// intrinsics are simply annotated with the nosync attribute in Intrinsics.td. | |||
1816 | bool AANoSyncImpl::isNoSyncIntrinsic(Instruction *I) { | |||
1817 | if (auto *MI = dyn_cast<MemIntrinsic>(I)) | |||
1818 | return !MI->isVolatile(); | |||
1819 | return false; | |||
1820 | } | |||
1821 | ||||
1822 | ChangeStatus AANoSyncImpl::updateImpl(Attributor &A) { | |||
1823 | ||||
1824 | auto CheckRWInstForNoSync = [&](Instruction &I) { | |||
1825 | /// We are looking for volatile instructions or Non-Relaxed atomics. | |||
1826 | ||||
1827 | if (const auto *CB = dyn_cast<CallBase>(&I)) { | |||
1828 | if (CB->hasFnAttr(Attribute::NoSync)) | |||
1829 | return true; | |||
1830 | ||||
1831 | if (isNoSyncIntrinsic(&I)) | |||
1832 | return true; | |||
1833 | ||||
1834 | const auto &NoSyncAA = A.getAAFor<AANoSync>( | |||
1835 | *this, IRPosition::callsite_function(*CB), DepClassTy::REQUIRED); | |||
1836 | return NoSyncAA.isAssumedNoSync(); | |||
1837 | } | |||
1838 | ||||
1839 | if (!I.isVolatile() && !isNonRelaxedAtomic(&I)) | |||
1840 | return true; | |||
1841 | ||||
1842 | return false; | |||
1843 | }; | |||
1844 | ||||
1845 | auto CheckForNoSync = [&](Instruction &I) { | |||
1846 | // At this point we handled all read/write effects and they are all | |||
1847 | // nosync, so they can be skipped. | |||
1848 | if (I.mayReadOrWriteMemory()) | |||
1849 | return true; | |||
1850 | ||||
1851 | // non-convergent and readnone imply nosync. | |||
1852 | return !cast<CallBase>(I).isConvergent(); | |||
1853 | }; | |||
1854 | ||||
1855 | bool UsedAssumedInformation = false; | |||
1856 | if (!A.checkForAllReadWriteInstructions(CheckRWInstForNoSync, *this, | |||
1857 | UsedAssumedInformation) || | |||
1858 | !A.checkForAllCallLikeInstructions(CheckForNoSync, *this, | |||
1859 | UsedAssumedInformation)) | |||
1860 | return indicatePessimisticFixpoint(); | |||
1861 | ||||
1862 | return ChangeStatus::UNCHANGED; | |||
1863 | } | |||
1864 | ||||
1865 | struct AANoSyncFunction final : public AANoSyncImpl { | |||
1866 | AANoSyncFunction(const IRPosition &IRP, Attributor &A) | |||
1867 | : AANoSyncImpl(IRP, A) {} | |||
1868 | ||||
1869 | /// See AbstractAttribute::trackStatistics() | |||
1870 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(nosync){ static llvm::Statistic NumIRFunction_nosync = {"attributor" , "NumIRFunction_nosync", ("Number of " "functions" " marked '" "nosync" "'")};; ++(NumIRFunction_nosync); } } | |||
1871 | }; | |||
1872 | ||||
1873 | /// NoSync attribute deduction for a call sites. | |||
1874 | struct AANoSyncCallSite final : AANoSyncImpl { | |||
1875 | AANoSyncCallSite(const IRPosition &IRP, Attributor &A) | |||
1876 | : AANoSyncImpl(IRP, A) {} | |||
1877 | ||||
1878 | /// See AbstractAttribute::initialize(...). | |||
1879 | void initialize(Attributor &A) override { | |||
1880 | AANoSyncImpl::initialize(A); | |||
1881 | Function *F = getAssociatedFunction(); | |||
1882 | if (!F || F->isDeclaration()) | |||
1883 | indicatePessimisticFixpoint(); | |||
1884 | } | |||
1885 | ||||
1886 | /// See AbstractAttribute::updateImpl(...). | |||
1887 | ChangeStatus updateImpl(Attributor &A) override { | |||
1888 | // TODO: Once we have call site specific value information we can provide | |||
1889 | // call site specific liveness information and then it makes | |||
1890 | // sense to specialize attributes for call sites arguments instead of | |||
1891 | // redirecting requests to the callee argument. | |||
1892 | Function *F = getAssociatedFunction(); | |||
1893 | const IRPosition &FnPos = IRPosition::function(*F); | |||
1894 | auto &FnAA = A.getAAFor<AANoSync>(*this, FnPos, DepClassTy::REQUIRED); | |||
1895 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
1896 | } | |||
1897 | ||||
1898 | /// See AbstractAttribute::trackStatistics() | |||
1899 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(nosync){ static llvm::Statistic NumIRCS_nosync = {"attributor", "NumIRCS_nosync" , ("Number of " "call site" " marked '" "nosync" "'")};; ++(NumIRCS_nosync ); }; } | |||
1900 | }; | |||
1901 | ||||
1902 | /// ------------------------ No-Free Attributes ---------------------------- | |||
1903 | ||||
1904 | struct AANoFreeImpl : public AANoFree { | |||
1905 | AANoFreeImpl(const IRPosition &IRP, Attributor &A) : AANoFree(IRP, A) {} | |||
1906 | ||||
1907 | /// See AbstractAttribute::updateImpl(...). | |||
1908 | ChangeStatus updateImpl(Attributor &A) override { | |||
1909 | auto CheckForNoFree = [&](Instruction &I) { | |||
1910 | const auto &CB = cast<CallBase>(I); | |||
1911 | if (CB.hasFnAttr(Attribute::NoFree)) | |||
1912 | return true; | |||
1913 | ||||
1914 | const auto &NoFreeAA = A.getAAFor<AANoFree>( | |||
1915 | *this, IRPosition::callsite_function(CB), DepClassTy::REQUIRED); | |||
1916 | return NoFreeAA.isAssumedNoFree(); | |||
1917 | }; | |||
1918 | ||||
1919 | bool UsedAssumedInformation = false; | |||
1920 | if (!A.checkForAllCallLikeInstructions(CheckForNoFree, *this, | |||
1921 | UsedAssumedInformation)) | |||
1922 | return indicatePessimisticFixpoint(); | |||
1923 | return ChangeStatus::UNCHANGED; | |||
1924 | } | |||
1925 | ||||
1926 | /// See AbstractAttribute::getAsStr(). | |||
1927 | const std::string getAsStr() const override { | |||
1928 | return getAssumed() ? "nofree" : "may-free"; | |||
1929 | } | |||
1930 | }; | |||
1931 | ||||
1932 | struct AANoFreeFunction final : public AANoFreeImpl { | |||
1933 | AANoFreeFunction(const IRPosition &IRP, Attributor &A) | |||
1934 | : AANoFreeImpl(IRP, A) {} | |||
1935 | ||||
1936 | /// See AbstractAttribute::trackStatistics() | |||
1937 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(nofree){ static llvm::Statistic NumIRFunction_nofree = {"attributor" , "NumIRFunction_nofree", ("Number of " "functions" " marked '" "nofree" "'")};; ++(NumIRFunction_nofree); } } | |||
1938 | }; | |||
1939 | ||||
1940 | /// NoFree attribute deduction for a call sites. | |||
1941 | struct AANoFreeCallSite final : AANoFreeImpl { | |||
1942 | AANoFreeCallSite(const IRPosition &IRP, Attributor &A) | |||
1943 | : AANoFreeImpl(IRP, A) {} | |||
1944 | ||||
1945 | /// See AbstractAttribute::initialize(...). | |||
1946 | void initialize(Attributor &A) override { | |||
1947 | AANoFreeImpl::initialize(A); | |||
1948 | Function *F = getAssociatedFunction(); | |||
1949 | if (!F || F->isDeclaration()) | |||
1950 | indicatePessimisticFixpoint(); | |||
1951 | } | |||
1952 | ||||
1953 | /// See AbstractAttribute::updateImpl(...). | |||
1954 | ChangeStatus updateImpl(Attributor &A) override { | |||
1955 | // TODO: Once we have call site specific value information we can provide | |||
1956 | // call site specific liveness information and then it makes | |||
1957 | // sense to specialize attributes for call sites arguments instead of | |||
1958 | // redirecting requests to the callee argument. | |||
1959 | Function *F = getAssociatedFunction(); | |||
1960 | const IRPosition &FnPos = IRPosition::function(*F); | |||
1961 | auto &FnAA = A.getAAFor<AANoFree>(*this, FnPos, DepClassTy::REQUIRED); | |||
1962 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
1963 | } | |||
1964 | ||||
1965 | /// See AbstractAttribute::trackStatistics() | |||
1966 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(nofree){ static llvm::Statistic NumIRCS_nofree = {"attributor", "NumIRCS_nofree" , ("Number of " "call site" " marked '" "nofree" "'")};; ++(NumIRCS_nofree ); }; } | |||
1967 | }; | |||
1968 | ||||
1969 | /// NoFree attribute for floating values. | |||
1970 | struct AANoFreeFloating : AANoFreeImpl { | |||
1971 | AANoFreeFloating(const IRPosition &IRP, Attributor &A) | |||
1972 | : AANoFreeImpl(IRP, A) {} | |||
1973 | ||||
1974 | /// See AbstractAttribute::trackStatistics() | |||
1975 | void trackStatistics() const override{STATS_DECLTRACK_FLOATING_ATTR(nofree){ static llvm::Statistic NumIRFloating_nofree = {"attributor" , "NumIRFloating_nofree", ("Number of floating values known to be '" "nofree" "'")};; ++(NumIRFloating_nofree); }} | |||
1976 | ||||
1977 | /// See Abstract Attribute::updateImpl(...). | |||
1978 | ChangeStatus updateImpl(Attributor &A) override { | |||
1979 | const IRPosition &IRP = getIRPosition(); | |||
1980 | ||||
1981 | const auto &NoFreeAA = A.getAAFor<AANoFree>( | |||
1982 | *this, IRPosition::function_scope(IRP), DepClassTy::OPTIONAL); | |||
1983 | if (NoFreeAA.isAssumedNoFree()) | |||
1984 | return ChangeStatus::UNCHANGED; | |||
1985 | ||||
1986 | Value &AssociatedValue = getIRPosition().getAssociatedValue(); | |||
1987 | auto Pred = [&](const Use &U, bool &Follow) -> bool { | |||
1988 | Instruction *UserI = cast<Instruction>(U.getUser()); | |||
1989 | if (auto *CB = dyn_cast<CallBase>(UserI)) { | |||
1990 | if (CB->isBundleOperand(&U)) | |||
1991 | return false; | |||
1992 | if (!CB->isArgOperand(&U)) | |||
1993 | return true; | |||
1994 | unsigned ArgNo = CB->getArgOperandNo(&U); | |||
1995 | ||||
1996 | const auto &NoFreeArg = A.getAAFor<AANoFree>( | |||
1997 | *this, IRPosition::callsite_argument(*CB, ArgNo), | |||
1998 | DepClassTy::REQUIRED); | |||
1999 | return NoFreeArg.isAssumedNoFree(); | |||
2000 | } | |||
2001 | ||||
2002 | if (isa<GetElementPtrInst>(UserI) || isa<BitCastInst>(UserI) || | |||
2003 | isa<PHINode>(UserI) || isa<SelectInst>(UserI)) { | |||
2004 | Follow = true; | |||
2005 | return true; | |||
2006 | } | |||
2007 | if (isa<StoreInst>(UserI) || isa<LoadInst>(UserI) || | |||
2008 | isa<ReturnInst>(UserI)) | |||
2009 | return true; | |||
2010 | ||||
2011 | // Unknown user. | |||
2012 | return false; | |||
2013 | }; | |||
2014 | if (!A.checkForAllUses(Pred, *this, AssociatedValue)) | |||
2015 | return indicatePessimisticFixpoint(); | |||
2016 | ||||
2017 | return ChangeStatus::UNCHANGED; | |||
2018 | } | |||
2019 | }; | |||
2020 | ||||
2021 | /// NoFree attribute for a call site argument. | |||
2022 | struct AANoFreeArgument final : AANoFreeFloating { | |||
2023 | AANoFreeArgument(const IRPosition &IRP, Attributor &A) | |||
2024 | : AANoFreeFloating(IRP, A) {} | |||
2025 | ||||
2026 | /// See AbstractAttribute::trackStatistics() | |||
2027 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(nofree){ static llvm::Statistic NumIRArguments_nofree = {"attributor" , "NumIRArguments_nofree", ("Number of " "arguments" " marked '" "nofree" "'")};; ++(NumIRArguments_nofree); } } | |||
2028 | }; | |||
2029 | ||||
2030 | /// NoFree attribute for call site arguments. | |||
2031 | struct AANoFreeCallSiteArgument final : AANoFreeFloating { | |||
2032 | AANoFreeCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
2033 | : AANoFreeFloating(IRP, A) {} | |||
2034 | ||||
2035 | /// See AbstractAttribute::updateImpl(...). | |||
2036 | ChangeStatus updateImpl(Attributor &A) override { | |||
2037 | // TODO: Once we have call site specific value information we can provide | |||
2038 | // call site specific liveness information and then it makes | |||
2039 | // sense to specialize attributes for call sites arguments instead of | |||
2040 | // redirecting requests to the callee argument. | |||
2041 | Argument *Arg = getAssociatedArgument(); | |||
2042 | if (!Arg) | |||
2043 | return indicatePessimisticFixpoint(); | |||
2044 | const IRPosition &ArgPos = IRPosition::argument(*Arg); | |||
2045 | auto &ArgAA = A.getAAFor<AANoFree>(*this, ArgPos, DepClassTy::REQUIRED); | |||
2046 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); | |||
2047 | } | |||
2048 | ||||
2049 | /// See AbstractAttribute::trackStatistics() | |||
2050 | void trackStatistics() const override{STATS_DECLTRACK_CSARG_ATTR(nofree){ static llvm::Statistic NumIRCSArguments_nofree = {"attributor" , "NumIRCSArguments_nofree", ("Number of " "call site arguments" " marked '" "nofree" "'")};; ++(NumIRCSArguments_nofree); }}; | |||
2051 | }; | |||
2052 | ||||
2053 | /// NoFree attribute for function return value. | |||
2054 | struct AANoFreeReturned final : AANoFreeFloating { | |||
2055 | AANoFreeReturned(const IRPosition &IRP, Attributor &A) | |||
2056 | : AANoFreeFloating(IRP, A) { | |||
2057 | llvm_unreachable("NoFree is not applicable to function returns!")__builtin_unreachable(); | |||
2058 | } | |||
2059 | ||||
2060 | /// See AbstractAttribute::initialize(...). | |||
2061 | void initialize(Attributor &A) override { | |||
2062 | llvm_unreachable("NoFree is not applicable to function returns!")__builtin_unreachable(); | |||
2063 | } | |||
2064 | ||||
2065 | /// See AbstractAttribute::updateImpl(...). | |||
2066 | ChangeStatus updateImpl(Attributor &A) override { | |||
2067 | llvm_unreachable("NoFree is not applicable to function returns!")__builtin_unreachable(); | |||
2068 | } | |||
2069 | ||||
2070 | /// See AbstractAttribute::trackStatistics() | |||
2071 | void trackStatistics() const override {} | |||
2072 | }; | |||
2073 | ||||
2074 | /// NoFree attribute deduction for a call site return value. | |||
2075 | struct AANoFreeCallSiteReturned final : AANoFreeFloating { | |||
2076 | AANoFreeCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
2077 | : AANoFreeFloating(IRP, A) {} | |||
2078 | ||||
2079 | ChangeStatus manifest(Attributor &A) override { | |||
2080 | return ChangeStatus::UNCHANGED; | |||
2081 | } | |||
2082 | /// See AbstractAttribute::trackStatistics() | |||
2083 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(nofree){ static llvm::Statistic NumIRCSReturn_nofree = {"attributor" , "NumIRCSReturn_nofree", ("Number of " "call site returns" " marked '" "nofree" "'")};; ++(NumIRCSReturn_nofree); } } | |||
2084 | }; | |||
2085 | ||||
2086 | /// ------------------------ NonNull Argument Attribute ------------------------ | |||
2087 | static int64_t getKnownNonNullAndDerefBytesForUse( | |||
2088 | Attributor &A, const AbstractAttribute &QueryingAA, Value &AssociatedValue, | |||
2089 | const Use *U, const Instruction *I, bool &IsNonNull, bool &TrackUse) { | |||
2090 | TrackUse = false; | |||
2091 | ||||
2092 | const Value *UseV = U->get(); | |||
2093 | if (!UseV->getType()->isPointerTy()) | |||
2094 | return 0; | |||
2095 | ||||
2096 | // We need to follow common pointer manipulation uses to the accesses they | |||
2097 | // feed into. We can try to be smart to avoid looking through things we do not | |||
2098 | // like for now, e.g., non-inbounds GEPs. | |||
2099 | if (isa<CastInst>(I)) { | |||
2100 | TrackUse = true; | |||
2101 | return 0; | |||
2102 | } | |||
2103 | ||||
2104 | if (isa<GetElementPtrInst>(I)) { | |||
2105 | TrackUse = true; | |||
2106 | return 0; | |||
2107 | } | |||
2108 | ||||
2109 | Type *PtrTy = UseV->getType(); | |||
2110 | const Function *F = I->getFunction(); | |||
2111 | bool NullPointerIsDefined = | |||
2112 | F ? llvm::NullPointerIsDefined(F, PtrTy->getPointerAddressSpace()) : true; | |||
2113 | const DataLayout &DL = A.getInfoCache().getDL(); | |||
2114 | if (const auto *CB = dyn_cast<CallBase>(I)) { | |||
2115 | if (CB->isBundleOperand(U)) { | |||
2116 | if (RetainedKnowledge RK = getKnowledgeFromUse( | |||
2117 | U, {Attribute::NonNull, Attribute::Dereferenceable})) { | |||
2118 | IsNonNull |= | |||
2119 | (RK.AttrKind == Attribute::NonNull || !NullPointerIsDefined); | |||
2120 | return RK.ArgValue; | |||
2121 | } | |||
2122 | return 0; | |||
2123 | } | |||
2124 | ||||
2125 | if (CB->isCallee(U)) { | |||
2126 | IsNonNull |= !NullPointerIsDefined; | |||
2127 | return 0; | |||
2128 | } | |||
2129 | ||||
2130 | unsigned ArgNo = CB->getArgOperandNo(U); | |||
2131 | IRPosition IRP = IRPosition::callsite_argument(*CB, ArgNo); | |||
2132 | // As long as we only use known information there is no need to track | |||
2133 | // dependences here. | |||
2134 | auto &DerefAA = | |||
2135 | A.getAAFor<AADereferenceable>(QueryingAA, IRP, DepClassTy::NONE); | |||
2136 | IsNonNull |= DerefAA.isKnownNonNull(); | |||
2137 | return DerefAA.getKnownDereferenceableBytes(); | |||
2138 | } | |||
2139 | ||||
2140 | int64_t Offset; | |||
2141 | const Value *Base = | |||
2142 | getMinimalBaseOfAccsesPointerOperand(A, QueryingAA, I, Offset, DL); | |||
2143 | if (Base) { | |||
2144 | if (Base == &AssociatedValue && | |||
2145 | getPointerOperand(I, /* AllowVolatile */ false) == UseV) { | |||
2146 | int64_t DerefBytes = | |||
2147 | (int64_t)DL.getTypeStoreSize(PtrTy->getPointerElementType()) + Offset; | |||
2148 | ||||
2149 | IsNonNull |= !NullPointerIsDefined; | |||
2150 | return std::max(int64_t(0), DerefBytes); | |||
2151 | } | |||
2152 | } | |||
2153 | ||||
2154 | /// Corner case when an offset is 0. | |||
2155 | Base = getBasePointerOfAccessPointerOperand(I, Offset, DL, | |||
2156 | /*AllowNonInbounds*/ true); | |||
2157 | if (Base) { | |||
2158 | if (Offset == 0 && Base == &AssociatedValue && | |||
2159 | getPointerOperand(I, /* AllowVolatile */ false) == UseV) { | |||
2160 | int64_t DerefBytes = | |||
2161 | (int64_t)DL.getTypeStoreSize(PtrTy->getPointerElementType()); | |||
2162 | IsNonNull |= !NullPointerIsDefined; | |||
2163 | return std::max(int64_t(0), DerefBytes); | |||
2164 | } | |||
2165 | } | |||
2166 | ||||
2167 | return 0; | |||
2168 | } | |||
2169 | ||||
2170 | struct AANonNullImpl : AANonNull { | |||
2171 | AANonNullImpl(const IRPosition &IRP, Attributor &A) | |||
2172 | : AANonNull(IRP, A), | |||
2173 | NullIsDefined(NullPointerIsDefined( | |||
2174 | getAnchorScope(), | |||
2175 | getAssociatedValue().getType()->getPointerAddressSpace())) {} | |||
2176 | ||||
2177 | /// See AbstractAttribute::initialize(...). | |||
2178 | void initialize(Attributor &A) override { | |||
2179 | Value &V = getAssociatedValue(); | |||
2180 | if (!NullIsDefined && | |||
2181 | hasAttr({Attribute::NonNull, Attribute::Dereferenceable}, | |||
2182 | /* IgnoreSubsumingPositions */ false, &A)) { | |||
2183 | indicateOptimisticFixpoint(); | |||
2184 | return; | |||
2185 | } | |||
2186 | ||||
2187 | if (isa<ConstantPointerNull>(V)) { | |||
2188 | indicatePessimisticFixpoint(); | |||
2189 | return; | |||
2190 | } | |||
2191 | ||||
2192 | AANonNull::initialize(A); | |||
2193 | ||||
2194 | bool CanBeNull, CanBeFreed; | |||
2195 | if (V.getPointerDereferenceableBytes(A.getDataLayout(), CanBeNull, | |||
2196 | CanBeFreed)) { | |||
2197 | if (!CanBeNull) { | |||
2198 | indicateOptimisticFixpoint(); | |||
2199 | return; | |||
2200 | } | |||
2201 | } | |||
2202 | ||||
2203 | if (isa<GlobalValue>(&getAssociatedValue())) { | |||
2204 | indicatePessimisticFixpoint(); | |||
2205 | return; | |||
2206 | } | |||
2207 | ||||
2208 | if (Instruction *CtxI = getCtxI()) | |||
2209 | followUsesInMBEC(*this, A, getState(), *CtxI); | |||
2210 | } | |||
2211 | ||||
2212 | /// See followUsesInMBEC | |||
2213 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, | |||
2214 | AANonNull::StateType &State) { | |||
2215 | bool IsNonNull = false; | |||
2216 | bool TrackUse = false; | |||
2217 | getKnownNonNullAndDerefBytesForUse(A, *this, getAssociatedValue(), U, I, | |||
2218 | IsNonNull, TrackUse); | |||
2219 | State.setKnown(IsNonNull); | |||
2220 | return TrackUse; | |||
2221 | } | |||
2222 | ||||
2223 | /// See AbstractAttribute::getAsStr(). | |||
2224 | const std::string getAsStr() const override { | |||
2225 | return getAssumed() ? "nonnull" : "may-null"; | |||
2226 | } | |||
2227 | ||||
2228 | /// Flag to determine if the underlying value can be null and still allow | |||
2229 | /// valid accesses. | |||
2230 | const bool NullIsDefined; | |||
2231 | }; | |||
2232 | ||||
2233 | /// NonNull attribute for a floating value. | |||
2234 | struct AANonNullFloating : public AANonNullImpl { | |||
2235 | AANonNullFloating(const IRPosition &IRP, Attributor &A) | |||
2236 | : AANonNullImpl(IRP, A) {} | |||
2237 | ||||
2238 | /// See AbstractAttribute::updateImpl(...). | |||
2239 | ChangeStatus updateImpl(Attributor &A) override { | |||
2240 | const DataLayout &DL = A.getDataLayout(); | |||
2241 | ||||
2242 | DominatorTree *DT = nullptr; | |||
2243 | AssumptionCache *AC = nullptr; | |||
2244 | InformationCache &InfoCache = A.getInfoCache(); | |||
2245 | if (const Function *Fn = getAnchorScope()) { | |||
2246 | DT = InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>(*Fn); | |||
2247 | AC = InfoCache.getAnalysisResultForFunction<AssumptionAnalysis>(*Fn); | |||
2248 | } | |||
2249 | ||||
2250 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, | |||
2251 | AANonNull::StateType &T, bool Stripped) -> bool { | |||
2252 | const auto &AA = A.getAAFor<AANonNull>(*this, IRPosition::value(V), | |||
2253 | DepClassTy::REQUIRED); | |||
2254 | if (!Stripped && this == &AA) { | |||
2255 | if (!isKnownNonZero(&V, DL, 0, AC, CtxI, DT)) | |||
2256 | T.indicatePessimisticFixpoint(); | |||
2257 | } else { | |||
2258 | // Use abstract attribute information. | |||
2259 | const AANonNull::StateType &NS = AA.getState(); | |||
2260 | T ^= NS; | |||
2261 | } | |||
2262 | return T.isValidState(); | |||
2263 | }; | |||
2264 | ||||
2265 | StateType T; | |||
2266 | if (!genericValueTraversal<StateType>(A, getIRPosition(), *this, T, | |||
2267 | VisitValueCB, getCtxI())) | |||
2268 | return indicatePessimisticFixpoint(); | |||
2269 | ||||
2270 | return clampStateAndIndicateChange(getState(), T); | |||
2271 | } | |||
2272 | ||||
2273 | /// See AbstractAttribute::trackStatistics() | |||
2274 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(nonnull){ static llvm::Statistic NumIRFunctionReturn_nonnull = {"attributor" , "NumIRFunctionReturn_nonnull", ("Number of " "function returns" " marked '" "nonnull" "'")};; ++(NumIRFunctionReturn_nonnull ); } } | |||
2275 | }; | |||
2276 | ||||
2277 | /// NonNull attribute for function return value. | |||
2278 | struct AANonNullReturned final | |||
2279 | : AAReturnedFromReturnedValues<AANonNull, AANonNull> { | |||
2280 | AANonNullReturned(const IRPosition &IRP, Attributor &A) | |||
2281 | : AAReturnedFromReturnedValues<AANonNull, AANonNull>(IRP, A) {} | |||
2282 | ||||
2283 | /// See AbstractAttribute::getAsStr(). | |||
2284 | const std::string getAsStr() const override { | |||
2285 | return getAssumed() ? "nonnull" : "may-null"; | |||
2286 | } | |||
2287 | ||||
2288 | /// See AbstractAttribute::trackStatistics() | |||
2289 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(nonnull){ static llvm::Statistic NumIRFunctionReturn_nonnull = {"attributor" , "NumIRFunctionReturn_nonnull", ("Number of " "function returns" " marked '" "nonnull" "'")};; ++(NumIRFunctionReturn_nonnull ); } } | |||
2290 | }; | |||
2291 | ||||
2292 | /// NonNull attribute for function argument. | |||
2293 | struct AANonNullArgument final | |||
2294 | : AAArgumentFromCallSiteArguments<AANonNull, AANonNullImpl> { | |||
2295 | AANonNullArgument(const IRPosition &IRP, Attributor &A) | |||
2296 | : AAArgumentFromCallSiteArguments<AANonNull, AANonNullImpl>(IRP, A) {} | |||
2297 | ||||
2298 | /// See AbstractAttribute::trackStatistics() | |||
2299 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(nonnull){ static llvm::Statistic NumIRArguments_nonnull = {"attributor" , "NumIRArguments_nonnull", ("Number of " "arguments" " marked '" "nonnull" "'")};; ++(NumIRArguments_nonnull); } } | |||
2300 | }; | |||
2301 | ||||
2302 | struct AANonNullCallSiteArgument final : AANonNullFloating { | |||
2303 | AANonNullCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
2304 | : AANonNullFloating(IRP, A) {} | |||
2305 | ||||
2306 | /// See AbstractAttribute::trackStatistics() | |||
2307 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(nonnull){ static llvm::Statistic NumIRCSArguments_nonnull = {"attributor" , "NumIRCSArguments_nonnull", ("Number of " "call site arguments" " marked '" "nonnull" "'")};; ++(NumIRCSArguments_nonnull); } } | |||
2308 | }; | |||
2309 | ||||
2310 | /// NonNull attribute for a call site return position. | |||
2311 | struct AANonNullCallSiteReturned final | |||
2312 | : AACallSiteReturnedFromReturned<AANonNull, AANonNullImpl> { | |||
2313 | AANonNullCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
2314 | : AACallSiteReturnedFromReturned<AANonNull, AANonNullImpl>(IRP, A) {} | |||
2315 | ||||
2316 | /// See AbstractAttribute::trackStatistics() | |||
2317 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(nonnull){ static llvm::Statistic NumIRCSReturn_nonnull = {"attributor" , "NumIRCSReturn_nonnull", ("Number of " "call site returns" " marked '" "nonnull" "'")};; ++(NumIRCSReturn_nonnull); } } | |||
2318 | }; | |||
2319 | ||||
2320 | /// ------------------------ No-Recurse Attributes ---------------------------- | |||
2321 | ||||
2322 | struct AANoRecurseImpl : public AANoRecurse { | |||
2323 | AANoRecurseImpl(const IRPosition &IRP, Attributor &A) : AANoRecurse(IRP, A) {} | |||
2324 | ||||
2325 | /// See AbstractAttribute::getAsStr() | |||
2326 | const std::string getAsStr() const override { | |||
2327 | return getAssumed() ? "norecurse" : "may-recurse"; | |||
2328 | } | |||
2329 | }; | |||
2330 | ||||
2331 | struct AANoRecurseFunction final : AANoRecurseImpl { | |||
2332 | AANoRecurseFunction(const IRPosition &IRP, Attributor &A) | |||
2333 | : AANoRecurseImpl(IRP, A) {} | |||
2334 | ||||
2335 | /// See AbstractAttribute::initialize(...). | |||
2336 | void initialize(Attributor &A) override { | |||
2337 | AANoRecurseImpl::initialize(A); | |||
2338 | if (const Function *F = getAnchorScope()) | |||
2339 | if (A.getInfoCache().getSccSize(*F) != 1) | |||
2340 | indicatePessimisticFixpoint(); | |||
2341 | } | |||
2342 | ||||
2343 | /// See AbstractAttribute::updateImpl(...). | |||
2344 | ChangeStatus updateImpl(Attributor &A) override { | |||
2345 | ||||
2346 | // If all live call sites are known to be no-recurse, we are as well. | |||
2347 | auto CallSitePred = [&](AbstractCallSite ACS) { | |||
2348 | const auto &NoRecurseAA = A.getAAFor<AANoRecurse>( | |||
2349 | *this, IRPosition::function(*ACS.getInstruction()->getFunction()), | |||
2350 | DepClassTy::NONE); | |||
2351 | return NoRecurseAA.isKnownNoRecurse(); | |||
2352 | }; | |||
2353 | bool AllCallSitesKnown; | |||
2354 | if (A.checkForAllCallSites(CallSitePred, *this, true, AllCallSitesKnown)) { | |||
2355 | // If we know all call sites and all are known no-recurse, we are done. | |||
2356 | // If all known call sites, which might not be all that exist, are known | |||
2357 | // to be no-recurse, we are not done but we can continue to assume | |||
2358 | // no-recurse. If one of the call sites we have not visited will become | |||
2359 | // live, another update is triggered. | |||
2360 | if (AllCallSitesKnown) | |||
2361 | indicateOptimisticFixpoint(); | |||
2362 | return ChangeStatus::UNCHANGED; | |||
2363 | } | |||
2364 | ||||
2365 | // If the above check does not hold anymore we look at the calls. | |||
2366 | auto CheckForNoRecurse = [&](Instruction &I) { | |||
2367 | const auto &CB = cast<CallBase>(I); | |||
2368 | if (CB.hasFnAttr(Attribute::NoRecurse)) | |||
2369 | return true; | |||
2370 | ||||
2371 | const auto &NoRecurseAA = A.getAAFor<AANoRecurse>( | |||
2372 | *this, IRPosition::callsite_function(CB), DepClassTy::REQUIRED); | |||
2373 | if (!NoRecurseAA.isAssumedNoRecurse()) | |||
2374 | return false; | |||
2375 | ||||
2376 | // Recursion to the same function | |||
2377 | if (CB.getCalledFunction() == getAnchorScope()) | |||
2378 | return false; | |||
2379 | ||||
2380 | return true; | |||
2381 | }; | |||
2382 | ||||
2383 | bool UsedAssumedInformation = false; | |||
2384 | if (!A.checkForAllCallLikeInstructions(CheckForNoRecurse, *this, | |||
2385 | UsedAssumedInformation)) | |||
2386 | return indicatePessimisticFixpoint(); | |||
2387 | return ChangeStatus::UNCHANGED; | |||
2388 | } | |||
2389 | ||||
2390 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(norecurse){ static llvm::Statistic NumIRFunction_norecurse = {"attributor" , "NumIRFunction_norecurse", ("Number of " "functions" " marked '" "norecurse" "'")};; ++(NumIRFunction_norecurse); } } | |||
2391 | }; | |||
2392 | ||||
2393 | /// NoRecurse attribute deduction for a call sites. | |||
2394 | struct AANoRecurseCallSite final : AANoRecurseImpl { | |||
2395 | AANoRecurseCallSite(const IRPosition &IRP, Attributor &A) | |||
2396 | : AANoRecurseImpl(IRP, A) {} | |||
2397 | ||||
2398 | /// See AbstractAttribute::initialize(...). | |||
2399 | void initialize(Attributor &A) override { | |||
2400 | AANoRecurseImpl::initialize(A); | |||
2401 | Function *F = getAssociatedFunction(); | |||
2402 | if (!F || F->isDeclaration()) | |||
2403 | indicatePessimisticFixpoint(); | |||
2404 | } | |||
2405 | ||||
2406 | /// See AbstractAttribute::updateImpl(...). | |||
2407 | ChangeStatus updateImpl(Attributor &A) override { | |||
2408 | // TODO: Once we have call site specific value information we can provide | |||
2409 | // call site specific liveness information and then it makes | |||
2410 | // sense to specialize attributes for call sites arguments instead of | |||
2411 | // redirecting requests to the callee argument. | |||
2412 | Function *F = getAssociatedFunction(); | |||
2413 | const IRPosition &FnPos = IRPosition::function(*F); | |||
2414 | auto &FnAA = A.getAAFor<AANoRecurse>(*this, FnPos, DepClassTy::REQUIRED); | |||
2415 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
2416 | } | |||
2417 | ||||
2418 | /// See AbstractAttribute::trackStatistics() | |||
2419 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(norecurse){ static llvm::Statistic NumIRCS_norecurse = {"attributor", "NumIRCS_norecurse" , ("Number of " "call site" " marked '" "norecurse" "'")};; ++ (NumIRCS_norecurse); }; } | |||
2420 | }; | |||
2421 | ||||
2422 | /// -------------------- Undefined-Behavior Attributes ------------------------ | |||
2423 | ||||
2424 | struct AAUndefinedBehaviorImpl : public AAUndefinedBehavior { | |||
2425 | AAUndefinedBehaviorImpl(const IRPosition &IRP, Attributor &A) | |||
2426 | : AAUndefinedBehavior(IRP, A) {} | |||
2427 | ||||
2428 | /// See AbstractAttribute::updateImpl(...). | |||
2429 | // through a pointer (i.e. also branches etc.) | |||
2430 | ChangeStatus updateImpl(Attributor &A) override { | |||
2431 | const size_t UBPrevSize = KnownUBInsts.size(); | |||
2432 | const size_t NoUBPrevSize = AssumedNoUBInsts.size(); | |||
2433 | ||||
2434 | auto InspectMemAccessInstForUB = [&](Instruction &I) { | |||
2435 | // Skip instructions that are already saved. | |||
2436 | if (AssumedNoUBInsts.count(&I) || KnownUBInsts.count(&I)) | |||
2437 | return true; | |||
2438 | ||||
2439 | // If we reach here, we know we have an instruction | |||
2440 | // that accesses memory through a pointer operand, | |||
2441 | // for which getPointerOperand() should give it to us. | |||
2442 | Value *PtrOp = | |||
2443 | const_cast<Value *>(getPointerOperand(&I, /* AllowVolatile */ true)); | |||
2444 | assert(PtrOp &&((void)0) | |||
2445 | "Expected pointer operand of memory accessing instruction")((void)0); | |||
2446 | ||||
2447 | // Either we stopped and the appropriate action was taken, | |||
2448 | // or we got back a simplified value to continue. | |||
2449 | Optional<Value *> SimplifiedPtrOp = stopOnUndefOrAssumed(A, PtrOp, &I); | |||
2450 | if (!SimplifiedPtrOp.hasValue() || !SimplifiedPtrOp.getValue()) | |||
2451 | return true; | |||
2452 | const Value *PtrOpVal = SimplifiedPtrOp.getValue(); | |||
2453 | ||||
2454 | // A memory access through a pointer is considered UB | |||
2455 | // only if the pointer has constant null value. | |||
2456 | // TODO: Expand it to not only check constant values. | |||
2457 | if (!isa<ConstantPointerNull>(PtrOpVal)) { | |||
2458 | AssumedNoUBInsts.insert(&I); | |||
2459 | return true; | |||
2460 | } | |||
2461 | const Type *PtrTy = PtrOpVal->getType(); | |||
2462 | ||||
2463 | // Because we only consider instructions inside functions, | |||
2464 | // assume that a parent function exists. | |||
2465 | const Function *F = I.getFunction(); | |||
2466 | ||||
2467 | // A memory access using constant null pointer is only considered UB | |||
2468 | // if null pointer is _not_ defined for the target platform. | |||
2469 | if (llvm::NullPointerIsDefined(F, PtrTy->getPointerAddressSpace())) | |||
2470 | AssumedNoUBInsts.insert(&I); | |||
2471 | else | |||
2472 | KnownUBInsts.insert(&I); | |||
2473 | return true; | |||
2474 | }; | |||
2475 | ||||
2476 | auto InspectBrInstForUB = [&](Instruction &I) { | |||
2477 | // A conditional branch instruction is considered UB if it has `undef` | |||
2478 | // condition. | |||
2479 | ||||
2480 | // Skip instructions that are already saved. | |||
2481 | if (AssumedNoUBInsts.count(&I) || KnownUBInsts.count(&I)) | |||
2482 | return true; | |||
2483 | ||||
2484 | // We know we have a branch instruction. | |||
2485 | auto *BrInst = cast<BranchInst>(&I); | |||
2486 | ||||
2487 | // Unconditional branches are never considered UB. | |||
2488 | if (BrInst->isUnconditional()) | |||
2489 | return true; | |||
2490 | ||||
2491 | // Either we stopped and the appropriate action was taken, | |||
2492 | // or we got back a simplified value to continue. | |||
2493 | Optional<Value *> SimplifiedCond = | |||
2494 | stopOnUndefOrAssumed(A, BrInst->getCondition(), BrInst); | |||
2495 | if (!SimplifiedCond.hasValue() || !SimplifiedCond.getValue()) | |||
2496 | return true; | |||
2497 | AssumedNoUBInsts.insert(&I); | |||
2498 | return true; | |||
2499 | }; | |||
2500 | ||||
2501 | auto InspectCallSiteForUB = [&](Instruction &I) { | |||
2502 | // Check whether a callsite always cause UB or not | |||
2503 | ||||
2504 | // Skip instructions that are already saved. | |||
2505 | if (AssumedNoUBInsts.count(&I) || KnownUBInsts.count(&I)) | |||
2506 | return true; | |||
2507 | ||||
2508 | // Check nonnull and noundef argument attribute violation for each | |||
2509 | // callsite. | |||
2510 | CallBase &CB = cast<CallBase>(I); | |||
2511 | Function *Callee = CB.getCalledFunction(); | |||
2512 | if (!Callee) | |||
2513 | return true; | |||
2514 | for (unsigned idx = 0; idx < CB.getNumArgOperands(); idx++) { | |||
2515 | // If current argument is known to be simplified to null pointer and the | |||
2516 | // corresponding argument position is known to have nonnull attribute, | |||
2517 | // the argument is poison. Furthermore, if the argument is poison and | |||
2518 | // the position is known to have noundef attriubte, this callsite is | |||
2519 | // considered UB. | |||
2520 | if (idx >= Callee->arg_size()) | |||
2521 | break; | |||
2522 | Value *ArgVal = CB.getArgOperand(idx); | |||
2523 | if (!ArgVal) | |||
2524 | continue; | |||
2525 | // Here, we handle three cases. | |||
2526 | // (1) Not having a value means it is dead. (we can replace the value | |||
2527 | // with undef) | |||
2528 | // (2) Simplified to undef. The argument violate noundef attriubte. | |||
2529 | // (3) Simplified to null pointer where known to be nonnull. | |||
2530 | // The argument is a poison value and violate noundef attribute. | |||
2531 | IRPosition CalleeArgumentIRP = IRPosition::callsite_argument(CB, idx); | |||
2532 | auto &NoUndefAA = | |||
2533 | A.getAAFor<AANoUndef>(*this, CalleeArgumentIRP, DepClassTy::NONE); | |||
2534 | if (!NoUndefAA.isKnownNoUndef()) | |||
2535 | continue; | |||
2536 | bool UsedAssumedInformation = false; | |||
2537 | Optional<Value *> SimplifiedVal = A.getAssumedSimplified( | |||
2538 | IRPosition::value(*ArgVal), *this, UsedAssumedInformation); | |||
2539 | if (UsedAssumedInformation) | |||
2540 | continue; | |||
2541 | if (SimplifiedVal.hasValue() && !SimplifiedVal.getValue()) | |||
2542 | return true; | |||
2543 | if (!SimplifiedVal.hasValue() || | |||
2544 | isa<UndefValue>(*SimplifiedVal.getValue())) { | |||
2545 | KnownUBInsts.insert(&I); | |||
2546 | continue; | |||
2547 | } | |||
2548 | if (!ArgVal->getType()->isPointerTy() || | |||
2549 | !isa<ConstantPointerNull>(*SimplifiedVal.getValue())) | |||
2550 | continue; | |||
2551 | auto &NonNullAA = | |||
2552 | A.getAAFor<AANonNull>(*this, CalleeArgumentIRP, DepClassTy::NONE); | |||
2553 | if (NonNullAA.isKnownNonNull()) | |||
2554 | KnownUBInsts.insert(&I); | |||
2555 | } | |||
2556 | return true; | |||
2557 | }; | |||
2558 | ||||
2559 | auto InspectReturnInstForUB = | |||
2560 | [&](Value &V, const SmallSetVector<ReturnInst *, 4> RetInsts) { | |||
2561 | // Check if a return instruction always cause UB or not | |||
2562 | // Note: It is guaranteed that the returned position of the anchor | |||
2563 | // scope has noundef attribute when this is called. | |||
2564 | // We also ensure the return position is not "assumed dead" | |||
2565 | // because the returned value was then potentially simplified to | |||
2566 | // `undef` in AAReturnedValues without removing the `noundef` | |||
2567 | // attribute yet. | |||
2568 | ||||
2569 | // When the returned position has noundef attriubte, UB occur in the | |||
2570 | // following cases. | |||
2571 | // (1) Returned value is known to be undef. | |||
2572 | // (2) The value is known to be a null pointer and the returned | |||
2573 | // position has nonnull attribute (because the returned value is | |||
2574 | // poison). | |||
2575 | bool FoundUB = false; | |||
2576 | if (isa<UndefValue>(V)) { | |||
2577 | FoundUB = true; | |||
2578 | } else { | |||
2579 | if (isa<ConstantPointerNull>(V)) { | |||
2580 | auto &NonNullAA = A.getAAFor<AANonNull>( | |||
2581 | *this, IRPosition::returned(*getAnchorScope()), | |||
2582 | DepClassTy::NONE); | |||
2583 | if (NonNullAA.isKnownNonNull()) | |||
2584 | FoundUB = true; | |||
2585 | } | |||
2586 | } | |||
2587 | ||||
2588 | if (FoundUB) | |||
2589 | for (ReturnInst *RI : RetInsts) | |||
2590 | KnownUBInsts.insert(RI); | |||
2591 | return true; | |||
2592 | }; | |||
2593 | ||||
2594 | bool UsedAssumedInformation = false; | |||
2595 | A.checkForAllInstructions(InspectMemAccessInstForUB, *this, | |||
2596 | {Instruction::Load, Instruction::Store, | |||
2597 | Instruction::AtomicCmpXchg, | |||
2598 | Instruction::AtomicRMW}, | |||
2599 | UsedAssumedInformation, | |||
2600 | /* CheckBBLivenessOnly */ true); | |||
2601 | A.checkForAllInstructions(InspectBrInstForUB, *this, {Instruction::Br}, | |||
2602 | UsedAssumedInformation, | |||
2603 | /* CheckBBLivenessOnly */ true); | |||
2604 | A.checkForAllCallLikeInstructions(InspectCallSiteForUB, *this, | |||
2605 | UsedAssumedInformation); | |||
2606 | ||||
2607 | // If the returned position of the anchor scope has noundef attriubte, check | |||
2608 | // all returned instructions. | |||
2609 | if (!getAnchorScope()->getReturnType()->isVoidTy()) { | |||
2610 | const IRPosition &ReturnIRP = IRPosition::returned(*getAnchorScope()); | |||
2611 | if (!A.isAssumedDead(ReturnIRP, this, nullptr, UsedAssumedInformation)) { | |||
2612 | auto &RetPosNoUndefAA = | |||
2613 | A.getAAFor<AANoUndef>(*this, ReturnIRP, DepClassTy::NONE); | |||
2614 | if (RetPosNoUndefAA.isKnownNoUndef()) | |||
2615 | A.checkForAllReturnedValuesAndReturnInsts(InspectReturnInstForUB, | |||
2616 | *this); | |||
2617 | } | |||
2618 | } | |||
2619 | ||||
2620 | if (NoUBPrevSize != AssumedNoUBInsts.size() || | |||
2621 | UBPrevSize != KnownUBInsts.size()) | |||
2622 | return ChangeStatus::CHANGED; | |||
2623 | return ChangeStatus::UNCHANGED; | |||
2624 | } | |||
2625 | ||||
2626 | bool isKnownToCauseUB(Instruction *I) const override { | |||
2627 | return KnownUBInsts.count(I); | |||
2628 | } | |||
2629 | ||||
2630 | bool isAssumedToCauseUB(Instruction *I) const override { | |||
2631 | // In simple words, if an instruction is not in the assumed to _not_ | |||
2632 | // cause UB, then it is assumed UB (that includes those | |||
2633 | // in the KnownUBInsts set). The rest is boilerplate | |||
2634 | // is to ensure that it is one of the instructions we test | |||
2635 | // for UB. | |||
2636 | ||||
2637 | switch (I->getOpcode()) { | |||
2638 | case Instruction::Load: | |||
2639 | case Instruction::Store: | |||
2640 | case Instruction::AtomicCmpXchg: | |||
2641 | case Instruction::AtomicRMW: | |||
2642 | return !AssumedNoUBInsts.count(I); | |||
2643 | case Instruction::Br: { | |||
2644 | auto BrInst = cast<BranchInst>(I); | |||
2645 | if (BrInst->isUnconditional()) | |||
2646 | return false; | |||
2647 | return !AssumedNoUBInsts.count(I); | |||
2648 | } break; | |||
2649 | default: | |||
2650 | return false; | |||
2651 | } | |||
2652 | return false; | |||
2653 | } | |||
2654 | ||||
2655 | ChangeStatus manifest(Attributor &A) override { | |||
2656 | if (KnownUBInsts.empty()) | |||
2657 | return ChangeStatus::UNCHANGED; | |||
2658 | for (Instruction *I : KnownUBInsts) | |||
2659 | A.changeToUnreachableAfterManifest(I); | |||
2660 | return ChangeStatus::CHANGED; | |||
2661 | } | |||
2662 | ||||
2663 | /// See AbstractAttribute::getAsStr() | |||
2664 | const std::string getAsStr() const override { | |||
2665 | return getAssumed() ? "undefined-behavior" : "no-ub"; | |||
2666 | } | |||
2667 | ||||
2668 | /// Note: The correctness of this analysis depends on the fact that the | |||
2669 | /// following 2 sets will stop changing after some point. | |||
2670 | /// "Change" here means that their size changes. | |||
2671 | /// The size of each set is monotonically increasing | |||
2672 | /// (we only add items to them) and it is upper bounded by the number of | |||
2673 | /// instructions in the processed function (we can never save more | |||
2674 | /// elements in either set than this number). Hence, at some point, | |||
2675 | /// they will stop increasing. | |||
2676 | /// Consequently, at some point, both sets will have stopped | |||
2677 | /// changing, effectively making the analysis reach a fixpoint. | |||
2678 | ||||
2679 | /// Note: These 2 sets are disjoint and an instruction can be considered | |||
2680 | /// one of 3 things: | |||
2681 | /// 1) Known to cause UB (AAUndefinedBehavior could prove it) and put it in | |||
2682 | /// the KnownUBInsts set. | |||
2683 | /// 2) Assumed to cause UB (in every updateImpl, AAUndefinedBehavior | |||
2684 | /// has a reason to assume it). | |||
2685 | /// 3) Assumed to not cause UB. very other instruction - AAUndefinedBehavior | |||
2686 | /// could not find a reason to assume or prove that it can cause UB, | |||
2687 | /// hence it assumes it doesn't. We have a set for these instructions | |||
2688 | /// so that we don't reprocess them in every update. | |||
2689 | /// Note however that instructions in this set may cause UB. | |||
2690 | ||||
2691 | protected: | |||
2692 | /// A set of all live instructions _known_ to cause UB. | |||
2693 | SmallPtrSet<Instruction *, 8> KnownUBInsts; | |||
2694 | ||||
2695 | private: | |||
2696 | /// A set of all the (live) instructions that are assumed to _not_ cause UB. | |||
2697 | SmallPtrSet<Instruction *, 8> AssumedNoUBInsts; | |||
2698 | ||||
2699 | // Should be called on updates in which if we're processing an instruction | |||
2700 | // \p I that depends on a value \p V, one of the following has to happen: | |||
2701 | // - If the value is assumed, then stop. | |||
2702 | // - If the value is known but undef, then consider it UB. | |||
2703 | // - Otherwise, do specific processing with the simplified value. | |||
2704 | // We return None in the first 2 cases to signify that an appropriate | |||
2705 | // action was taken and the caller should stop. | |||
2706 | // Otherwise, we return the simplified value that the caller should | |||
2707 | // use for specific processing. | |||
2708 | Optional<Value *> stopOnUndefOrAssumed(Attributor &A, Value *V, | |||
2709 | Instruction *I) { | |||
2710 | bool UsedAssumedInformation = false; | |||
2711 | Optional<Value *> SimplifiedV = A.getAssumedSimplified( | |||
2712 | IRPosition::value(*V), *this, UsedAssumedInformation); | |||
2713 | if (!UsedAssumedInformation) { | |||
2714 | // Don't depend on assumed values. | |||
2715 | if (!SimplifiedV.hasValue()) { | |||
2716 | // If it is known (which we tested above) but it doesn't have a value, | |||
2717 | // then we can assume `undef` and hence the instruction is UB. | |||
2718 | KnownUBInsts.insert(I); | |||
2719 | return llvm::None; | |||
2720 | } | |||
2721 | if (!SimplifiedV.getValue()) | |||
2722 | return nullptr; | |||
2723 | V = *SimplifiedV; | |||
2724 | } | |||
2725 | if (isa<UndefValue>(V)) { | |||
2726 | KnownUBInsts.insert(I); | |||
2727 | return llvm::None; | |||
2728 | } | |||
2729 | return V; | |||
2730 | } | |||
2731 | }; | |||
2732 | ||||
2733 | struct AAUndefinedBehaviorFunction final : AAUndefinedBehaviorImpl { | |||
2734 | AAUndefinedBehaviorFunction(const IRPosition &IRP, Attributor &A) | |||
2735 | : AAUndefinedBehaviorImpl(IRP, A) {} | |||
2736 | ||||
2737 | /// See AbstractAttribute::trackStatistics() | |||
2738 | void trackStatistics() const override { | |||
2739 | STATS_DECL(UndefinedBehaviorInstruction, Instruction,static llvm::Statistic NumIRInstruction_UndefinedBehaviorInstruction = {"attributor", "NumIRInstruction_UndefinedBehaviorInstruction" , "Number of instructions known to have UB"};; | |||
2740 | "Number of instructions known to have UB")static llvm::Statistic NumIRInstruction_UndefinedBehaviorInstruction = {"attributor", "NumIRInstruction_UndefinedBehaviorInstruction" , "Number of instructions known to have UB"};;; | |||
2741 | BUILD_STAT_NAME(UndefinedBehaviorInstruction, Instruction)NumIRInstruction_UndefinedBehaviorInstruction += | |||
2742 | KnownUBInsts.size(); | |||
2743 | } | |||
2744 | }; | |||
2745 | ||||
2746 | /// ------------------------ Will-Return Attributes ---------------------------- | |||
2747 | ||||
2748 | // Helper function that checks whether a function has any cycle which we don't | |||
2749 | // know if it is bounded or not. | |||
2750 | // Loops with maximum trip count are considered bounded, any other cycle not. | |||
2751 | static bool mayContainUnboundedCycle(Function &F, Attributor &A) { | |||
2752 | ScalarEvolution *SE = | |||
2753 | A.getInfoCache().getAnalysisResultForFunction<ScalarEvolutionAnalysis>(F); | |||
2754 | LoopInfo *LI = A.getInfoCache().getAnalysisResultForFunction<LoopAnalysis>(F); | |||
2755 | // If either SCEV or LoopInfo is not available for the function then we assume | |||
2756 | // any cycle to be unbounded cycle. | |||
2757 | // We use scc_iterator which uses Tarjan algorithm to find all the maximal | |||
2758 | // SCCs.To detect if there's a cycle, we only need to find the maximal ones. | |||
2759 | if (!SE || !LI) { | |||
2760 | for (scc_iterator<Function *> SCCI = scc_begin(&F); !SCCI.isAtEnd(); ++SCCI) | |||
2761 | if (SCCI.hasCycle()) | |||
2762 | return true; | |||
2763 | return false; | |||
2764 | } | |||
2765 | ||||
2766 | // If there's irreducible control, the function may contain non-loop cycles. | |||
2767 | if (mayContainIrreducibleControl(F, LI)) | |||
2768 | return true; | |||
2769 | ||||
2770 | // Any loop that does not have a max trip count is considered unbounded cycle. | |||
2771 | for (auto *L : LI->getLoopsInPreorder()) { | |||
2772 | if (!SE->getSmallConstantMaxTripCount(L)) | |||
2773 | return true; | |||
2774 | } | |||
2775 | return false; | |||
2776 | } | |||
2777 | ||||
2778 | struct AAWillReturnImpl : public AAWillReturn { | |||
2779 | AAWillReturnImpl(const IRPosition &IRP, Attributor &A) | |||
2780 | : AAWillReturn(IRP, A) {} | |||
2781 | ||||
2782 | /// See AbstractAttribute::initialize(...). | |||
2783 | void initialize(Attributor &A) override { | |||
2784 | AAWillReturn::initialize(A); | |||
2785 | ||||
2786 | if (isImpliedByMustprogressAndReadonly(A, /* KnownOnly */ true)) { | |||
2787 | indicateOptimisticFixpoint(); | |||
2788 | return; | |||
2789 | } | |||
2790 | } | |||
2791 | ||||
2792 | /// Check for `mustprogress` and `readonly` as they imply `willreturn`. | |||
2793 | bool isImpliedByMustprogressAndReadonly(Attributor &A, bool KnownOnly) { | |||
2794 | // Check for `mustprogress` in the scope and the associated function which | |||
2795 | // might be different if this is a call site. | |||
2796 | if ((!getAnchorScope() || !getAnchorScope()->mustProgress()) && | |||
2797 | (!getAssociatedFunction() || !getAssociatedFunction()->mustProgress())) | |||
2798 | return false; | |||
2799 | ||||
2800 | const auto &MemAA = | |||
2801 | A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), DepClassTy::NONE); | |||
2802 | if (!MemAA.isAssumedReadOnly()) | |||
2803 | return false; | |||
2804 | if (KnownOnly && !MemAA.isKnownReadOnly()) | |||
2805 | return false; | |||
2806 | if (!MemAA.isKnownReadOnly()) | |||
2807 | A.recordDependence(MemAA, *this, DepClassTy::OPTIONAL); | |||
2808 | ||||
2809 | return true; | |||
2810 | } | |||
2811 | ||||
2812 | /// See AbstractAttribute::updateImpl(...). | |||
2813 | ChangeStatus updateImpl(Attributor &A) override { | |||
2814 | if (isImpliedByMustprogressAndReadonly(A, /* KnownOnly */ false)) | |||
2815 | return ChangeStatus::UNCHANGED; | |||
2816 | ||||
2817 | auto CheckForWillReturn = [&](Instruction &I) { | |||
2818 | IRPosition IPos = IRPosition::callsite_function(cast<CallBase>(I)); | |||
2819 | const auto &WillReturnAA = | |||
2820 | A.getAAFor<AAWillReturn>(*this, IPos, DepClassTy::REQUIRED); | |||
2821 | if (WillReturnAA.isKnownWillReturn()) | |||
2822 | return true; | |||
2823 | if (!WillReturnAA.isAssumedWillReturn()) | |||
2824 | return false; | |||
2825 | const auto &NoRecurseAA = | |||
2826 | A.getAAFor<AANoRecurse>(*this, IPos, DepClassTy::REQUIRED); | |||
2827 | return NoRecurseAA.isAssumedNoRecurse(); | |||
2828 | }; | |||
2829 | ||||
2830 | bool UsedAssumedInformation = false; | |||
2831 | if (!A.checkForAllCallLikeInstructions(CheckForWillReturn, *this, | |||
2832 | UsedAssumedInformation)) | |||
2833 | return indicatePessimisticFixpoint(); | |||
2834 | ||||
2835 | return ChangeStatus::UNCHANGED; | |||
2836 | } | |||
2837 | ||||
2838 | /// See AbstractAttribute::getAsStr() | |||
2839 | const std::string getAsStr() const override { | |||
2840 | return getAssumed() ? "willreturn" : "may-noreturn"; | |||
2841 | } | |||
2842 | }; | |||
2843 | ||||
2844 | struct AAWillReturnFunction final : AAWillReturnImpl { | |||
2845 | AAWillReturnFunction(const IRPosition &IRP, Attributor &A) | |||
2846 | : AAWillReturnImpl(IRP, A) {} | |||
2847 | ||||
2848 | /// See AbstractAttribute::initialize(...). | |||
2849 | void initialize(Attributor &A) override { | |||
2850 | AAWillReturnImpl::initialize(A); | |||
2851 | ||||
2852 | Function *F = getAnchorScope(); | |||
2853 | if (!F || F->isDeclaration() || mayContainUnboundedCycle(*F, A)) | |||
2854 | indicatePessimisticFixpoint(); | |||
2855 | } | |||
2856 | ||||
2857 | /// See AbstractAttribute::trackStatistics() | |||
2858 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(willreturn){ static llvm::Statistic NumIRFunction_willreturn = {"attributor" , "NumIRFunction_willreturn", ("Number of " "functions" " marked '" "willreturn" "'")};; ++(NumIRFunction_willreturn); } } | |||
2859 | }; | |||
2860 | ||||
2861 | /// WillReturn attribute deduction for a call sites. | |||
2862 | struct AAWillReturnCallSite final : AAWillReturnImpl { | |||
2863 | AAWillReturnCallSite(const IRPosition &IRP, Attributor &A) | |||
2864 | : AAWillReturnImpl(IRP, A) {} | |||
2865 | ||||
2866 | /// See AbstractAttribute::initialize(...). | |||
2867 | void initialize(Attributor &A) override { | |||
2868 | AAWillReturnImpl::initialize(A); | |||
2869 | Function *F = getAssociatedFunction(); | |||
2870 | if (!F || !A.isFunctionIPOAmendable(*F)) | |||
2871 | indicatePessimisticFixpoint(); | |||
2872 | } | |||
2873 | ||||
2874 | /// See AbstractAttribute::updateImpl(...). | |||
2875 | ChangeStatus updateImpl(Attributor &A) override { | |||
2876 | if (isImpliedByMustprogressAndReadonly(A, /* KnownOnly */ false)) | |||
2877 | return ChangeStatus::UNCHANGED; | |||
2878 | ||||
2879 | // TODO: Once we have call site specific value information we can provide | |||
2880 | // call site specific liveness information and then it makes | |||
2881 | // sense to specialize attributes for call sites arguments instead of | |||
2882 | // redirecting requests to the callee argument. | |||
2883 | Function *F = getAssociatedFunction(); | |||
2884 | const IRPosition &FnPos = IRPosition::function(*F); | |||
2885 | auto &FnAA = A.getAAFor<AAWillReturn>(*this, FnPos, DepClassTy::REQUIRED); | |||
2886 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
2887 | } | |||
2888 | ||||
2889 | /// See AbstractAttribute::trackStatistics() | |||
2890 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(willreturn){ static llvm::Statistic NumIRCS_willreturn = {"attributor", "NumIRCS_willreturn" , ("Number of " "call site" " marked '" "willreturn" "'")};; ++ (NumIRCS_willreturn); }; } | |||
2891 | }; | |||
2892 | ||||
2893 | /// -------------------AAReachability Attribute-------------------------- | |||
2894 | ||||
2895 | struct AAReachabilityImpl : AAReachability { | |||
2896 | AAReachabilityImpl(const IRPosition &IRP, Attributor &A) | |||
2897 | : AAReachability(IRP, A) {} | |||
2898 | ||||
2899 | const std::string getAsStr() const override { | |||
2900 | // TODO: Return the number of reachable queries. | |||
2901 | return "reachable"; | |||
2902 | } | |||
2903 | ||||
2904 | /// See AbstractAttribute::updateImpl(...). | |||
2905 | ChangeStatus updateImpl(Attributor &A) override { | |||
2906 | return ChangeStatus::UNCHANGED; | |||
2907 | } | |||
2908 | }; | |||
2909 | ||||
2910 | struct AAReachabilityFunction final : public AAReachabilityImpl { | |||
2911 | AAReachabilityFunction(const IRPosition &IRP, Attributor &A) | |||
2912 | : AAReachabilityImpl(IRP, A) {} | |||
2913 | ||||
2914 | /// See AbstractAttribute::trackStatistics() | |||
2915 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(reachable){ static llvm::Statistic NumIRFunction_reachable = {"attributor" , "NumIRFunction_reachable", ("Number of " "functions" " marked '" "reachable" "'")};; ++(NumIRFunction_reachable); }; } | |||
2916 | }; | |||
2917 | ||||
2918 | /// ------------------------ NoAlias Argument Attribute ------------------------ | |||
2919 | ||||
2920 | struct AANoAliasImpl : AANoAlias { | |||
2921 | AANoAliasImpl(const IRPosition &IRP, Attributor &A) : AANoAlias(IRP, A) { | |||
2922 | assert(getAssociatedType()->isPointerTy() &&((void)0) | |||
2923 | "Noalias is a pointer attribute")((void)0); | |||
2924 | } | |||
2925 | ||||
2926 | const std::string getAsStr() const override { | |||
2927 | return getAssumed() ? "noalias" : "may-alias"; | |||
2928 | } | |||
2929 | }; | |||
2930 | ||||
2931 | /// NoAlias attribute for a floating value. | |||
2932 | struct AANoAliasFloating final : AANoAliasImpl { | |||
2933 | AANoAliasFloating(const IRPosition &IRP, Attributor &A) | |||
2934 | : AANoAliasImpl(IRP, A) {} | |||
2935 | ||||
2936 | /// See AbstractAttribute::initialize(...). | |||
2937 | void initialize(Attributor &A) override { | |||
2938 | AANoAliasImpl::initialize(A); | |||
2939 | Value *Val = &getAssociatedValue(); | |||
2940 | do { | |||
2941 | CastInst *CI = dyn_cast<CastInst>(Val); | |||
2942 | if (!CI) | |||
2943 | break; | |||
2944 | Value *Base = CI->getOperand(0); | |||
2945 | if (!Base->hasOneUse()) | |||
2946 | break; | |||
2947 | Val = Base; | |||
2948 | } while (true); | |||
2949 | ||||
2950 | if (!Val->getType()->isPointerTy()) { | |||
2951 | indicatePessimisticFixpoint(); | |||
2952 | return; | |||
2953 | } | |||
2954 | ||||
2955 | if (isa<AllocaInst>(Val)) | |||
2956 | indicateOptimisticFixpoint(); | |||
2957 | else if (isa<ConstantPointerNull>(Val) && | |||
2958 | !NullPointerIsDefined(getAnchorScope(), | |||
2959 | Val->getType()->getPointerAddressSpace())) | |||
2960 | indicateOptimisticFixpoint(); | |||
2961 | else if (Val != &getAssociatedValue()) { | |||
2962 | const auto &ValNoAliasAA = A.getAAFor<AANoAlias>( | |||
2963 | *this, IRPosition::value(*Val), DepClassTy::OPTIONAL); | |||
2964 | if (ValNoAliasAA.isKnownNoAlias()) | |||
2965 | indicateOptimisticFixpoint(); | |||
2966 | } | |||
2967 | } | |||
2968 | ||||
2969 | /// See AbstractAttribute::updateImpl(...). | |||
2970 | ChangeStatus updateImpl(Attributor &A) override { | |||
2971 | // TODO: Implement this. | |||
2972 | return indicatePessimisticFixpoint(); | |||
2973 | } | |||
2974 | ||||
2975 | /// See AbstractAttribute::trackStatistics() | |||
2976 | void trackStatistics() const override { | |||
2977 | STATS_DECLTRACK_FLOATING_ATTR(noalias){ static llvm::Statistic NumIRFloating_noalias = {"attributor" , "NumIRFloating_noalias", ("Number of floating values known to be '" "noalias" "'")};; ++(NumIRFloating_noalias); } | |||
2978 | } | |||
2979 | }; | |||
2980 | ||||
2981 | /// NoAlias attribute for an argument. | |||
2982 | struct AANoAliasArgument final | |||
2983 | : AAArgumentFromCallSiteArguments<AANoAlias, AANoAliasImpl> { | |||
2984 | using Base = AAArgumentFromCallSiteArguments<AANoAlias, AANoAliasImpl>; | |||
2985 | AANoAliasArgument(const IRPosition &IRP, Attributor &A) : Base(IRP, A) {} | |||
2986 | ||||
2987 | /// See AbstractAttribute::initialize(...). | |||
2988 | void initialize(Attributor &A) override { | |||
2989 | Base::initialize(A); | |||
2990 | // See callsite argument attribute and callee argument attribute. | |||
2991 | if (hasAttr({Attribute::ByVal})) | |||
2992 | indicateOptimisticFixpoint(); | |||
2993 | } | |||
2994 | ||||
2995 | /// See AbstractAttribute::update(...). | |||
2996 | ChangeStatus updateImpl(Attributor &A) override { | |||
2997 | // We have to make sure no-alias on the argument does not break | |||
2998 | // synchronization when this is a callback argument, see also [1] below. | |||
2999 | // If synchronization cannot be affected, we delegate to the base updateImpl | |||
3000 | // function, otherwise we give up for now. | |||
3001 | ||||
3002 | // If the function is no-sync, no-alias cannot break synchronization. | |||
3003 | const auto &NoSyncAA = | |||
3004 | A.getAAFor<AANoSync>(*this, IRPosition::function_scope(getIRPosition()), | |||
3005 | DepClassTy::OPTIONAL); | |||
3006 | if (NoSyncAA.isAssumedNoSync()) | |||
3007 | return Base::updateImpl(A); | |||
3008 | ||||
3009 | // If the argument is read-only, no-alias cannot break synchronization. | |||
3010 | const auto &MemBehaviorAA = A.getAAFor<AAMemoryBehavior>( | |||
3011 | *this, getIRPosition(), DepClassTy::OPTIONAL); | |||
3012 | if (MemBehaviorAA.isAssumedReadOnly()) | |||
3013 | return Base::updateImpl(A); | |||
3014 | ||||
3015 | // If the argument is never passed through callbacks, no-alias cannot break | |||
3016 | // synchronization. | |||
3017 | bool AllCallSitesKnown; | |||
3018 | if (A.checkForAllCallSites( | |||
3019 | [](AbstractCallSite ACS) { return !ACS.isCallbackCall(); }, *this, | |||
3020 | true, AllCallSitesKnown)) | |||
3021 | return Base::updateImpl(A); | |||
3022 | ||||
3023 | // TODO: add no-alias but make sure it doesn't break synchronization by | |||
3024 | // introducing fake uses. See: | |||
3025 | // [1] Compiler Optimizations for OpenMP, J. Doerfert and H. Finkel, | |||
3026 | // International Workshop on OpenMP 2018, | |||
3027 | // http://compilers.cs.uni-saarland.de/people/doerfert/par_opt18.pdf | |||
3028 | ||||
3029 | return indicatePessimisticFixpoint(); | |||
3030 | } | |||
3031 | ||||
3032 | /// See AbstractAttribute::trackStatistics() | |||
3033 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(noalias){ static llvm::Statistic NumIRArguments_noalias = {"attributor" , "NumIRArguments_noalias", ("Number of " "arguments" " marked '" "noalias" "'")};; ++(NumIRArguments_noalias); } } | |||
3034 | }; | |||
3035 | ||||
3036 | struct AANoAliasCallSiteArgument final : AANoAliasImpl { | |||
3037 | AANoAliasCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
3038 | : AANoAliasImpl(IRP, A) {} | |||
3039 | ||||
3040 | /// See AbstractAttribute::initialize(...). | |||
3041 | void initialize(Attributor &A) override { | |||
3042 | // See callsite argument attribute and callee argument attribute. | |||
3043 | const auto &CB = cast<CallBase>(getAnchorValue()); | |||
3044 | if (CB.paramHasAttr(getCallSiteArgNo(), Attribute::NoAlias)) | |||
3045 | indicateOptimisticFixpoint(); | |||
3046 | Value &Val = getAssociatedValue(); | |||
3047 | if (isa<ConstantPointerNull>(Val) && | |||
3048 | !NullPointerIsDefined(getAnchorScope(), | |||
3049 | Val.getType()->getPointerAddressSpace())) | |||
3050 | indicateOptimisticFixpoint(); | |||
3051 | } | |||
3052 | ||||
3053 | /// Determine if the underlying value may alias with the call site argument | |||
3054 | /// \p OtherArgNo of \p ICS (= the underlying call site). | |||
3055 | bool mayAliasWithArgument(Attributor &A, AAResults *&AAR, | |||
3056 | const AAMemoryBehavior &MemBehaviorAA, | |||
3057 | const CallBase &CB, unsigned OtherArgNo) { | |||
3058 | // We do not need to worry about aliasing with the underlying IRP. | |||
3059 | if (this->getCalleeArgNo() == (int)OtherArgNo) | |||
3060 | return false; | |||
3061 | ||||
3062 | // If it is not a pointer or pointer vector we do not alias. | |||
3063 | const Value *ArgOp = CB.getArgOperand(OtherArgNo); | |||
3064 | if (!ArgOp->getType()->isPtrOrPtrVectorTy()) | |||
3065 | return false; | |||
3066 | ||||
3067 | auto &CBArgMemBehaviorAA = A.getAAFor<AAMemoryBehavior>( | |||
3068 | *this, IRPosition::callsite_argument(CB, OtherArgNo), DepClassTy::NONE); | |||
3069 | ||||
3070 | // If the argument is readnone, there is no read-write aliasing. | |||
3071 | if (CBArgMemBehaviorAA.isAssumedReadNone()) { | |||
3072 | A.recordDependence(CBArgMemBehaviorAA, *this, DepClassTy::OPTIONAL); | |||
3073 | return false; | |||
3074 | } | |||
3075 | ||||
3076 | // If the argument is readonly and the underlying value is readonly, there | |||
3077 | // is no read-write aliasing. | |||
3078 | bool IsReadOnly = MemBehaviorAA.isAssumedReadOnly(); | |||
3079 | if (CBArgMemBehaviorAA.isAssumedReadOnly() && IsReadOnly) { | |||
3080 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); | |||
3081 | A.recordDependence(CBArgMemBehaviorAA, *this, DepClassTy::OPTIONAL); | |||
3082 | return false; | |||
3083 | } | |||
3084 | ||||
3085 | // We have to utilize actual alias analysis queries so we need the object. | |||
3086 | if (!AAR) | |||
3087 | AAR = A.getInfoCache().getAAResultsForFunction(*getAnchorScope()); | |||
3088 | ||||
3089 | // Try to rule it out at the call site. | |||
3090 | bool IsAliasing = !AAR || !AAR->isNoAlias(&getAssociatedValue(), ArgOp); | |||
3091 | LLVM_DEBUG(dbgs() << "[NoAliasCSArg] Check alias between "do { } while (false) | |||
3092 | "callsite arguments: "do { } while (false) | |||
3093 | << getAssociatedValue() << " " << *ArgOp << " => "do { } while (false) | |||
3094 | << (IsAliasing ? "" : "no-") << "alias \n")do { } while (false); | |||
3095 | ||||
3096 | return IsAliasing; | |||
3097 | } | |||
3098 | ||||
3099 | bool | |||
3100 | isKnownNoAliasDueToNoAliasPreservation(Attributor &A, AAResults *&AAR, | |||
3101 | const AAMemoryBehavior &MemBehaviorAA, | |||
3102 | const AANoAlias &NoAliasAA) { | |||
3103 | // We can deduce "noalias" if the following conditions hold. | |||
3104 | // (i) Associated value is assumed to be noalias in the definition. | |||
3105 | // (ii) Associated value is assumed to be no-capture in all the uses | |||
3106 | // possibly executed before this callsite. | |||
3107 | // (iii) There is no other pointer argument which could alias with the | |||
3108 | // value. | |||
3109 | ||||
3110 | bool AssociatedValueIsNoAliasAtDef = NoAliasAA.isAssumedNoAlias(); | |||
3111 | if (!AssociatedValueIsNoAliasAtDef) { | |||
3112 | LLVM_DEBUG(dbgs() << "[AANoAlias] " << getAssociatedValue()do { } while (false) | |||
3113 | << " is not no-alias at the definition\n")do { } while (false); | |||
3114 | return false; | |||
3115 | } | |||
3116 | ||||
3117 | A.recordDependence(NoAliasAA, *this, DepClassTy::OPTIONAL); | |||
3118 | ||||
3119 | const IRPosition &VIRP = IRPosition::value(getAssociatedValue()); | |||
3120 | const Function *ScopeFn = VIRP.getAnchorScope(); | |||
3121 | auto &NoCaptureAA = A.getAAFor<AANoCapture>(*this, VIRP, DepClassTy::NONE); | |||
3122 | // Check whether the value is captured in the scope using AANoCapture. | |||
3123 | // Look at CFG and check only uses possibly executed before this | |||
3124 | // callsite. | |||
3125 | auto UsePred = [&](const Use &U, bool &Follow) -> bool { | |||
3126 | Instruction *UserI = cast<Instruction>(U.getUser()); | |||
3127 | ||||
3128 | // If UserI is the curr instruction and there is a single potential use of | |||
3129 | // the value in UserI we allow the use. | |||
3130 | // TODO: We should inspect the operands and allow those that cannot alias | |||
3131 | // with the value. | |||
3132 | if (UserI == getCtxI() && UserI->getNumOperands() == 1) | |||
3133 | return true; | |||
3134 | ||||
3135 | if (ScopeFn) { | |||
3136 | const auto &ReachabilityAA = A.getAAFor<AAReachability>( | |||
3137 | *this, IRPosition::function(*ScopeFn), DepClassTy::OPTIONAL); | |||
3138 | ||||
3139 | if (!ReachabilityAA.isAssumedReachable(A, *UserI, *getCtxI())) | |||
3140 | return true; | |||
3141 | ||||
3142 | if (auto *CB = dyn_cast<CallBase>(UserI)) { | |||
3143 | if (CB->isArgOperand(&U)) { | |||
3144 | ||||
3145 | unsigned ArgNo = CB->getArgOperandNo(&U); | |||
3146 | ||||
3147 | const auto &NoCaptureAA = A.getAAFor<AANoCapture>( | |||
3148 | *this, IRPosition::callsite_argument(*CB, ArgNo), | |||
3149 | DepClassTy::OPTIONAL); | |||
3150 | ||||
3151 | if (NoCaptureAA.isAssumedNoCapture()) | |||
3152 | return true; | |||
3153 | } | |||
3154 | } | |||
3155 | } | |||
3156 | ||||
3157 | // For cases which can potentially have more users | |||
3158 | if (isa<GetElementPtrInst>(U) || isa<BitCastInst>(U) || isa<PHINode>(U) || | |||
3159 | isa<SelectInst>(U)) { | |||
3160 | Follow = true; | |||
3161 | return true; | |||
3162 | } | |||
3163 | ||||
3164 | LLVM_DEBUG(dbgs() << "[AANoAliasCSArg] Unknown user: " << *U << "\n")do { } while (false); | |||
3165 | return false; | |||
3166 | }; | |||
3167 | ||||
3168 | if (!NoCaptureAA.isAssumedNoCaptureMaybeReturned()) { | |||
3169 | if (!A.checkForAllUses(UsePred, *this, getAssociatedValue())) { | |||
3170 | LLVM_DEBUG(do { } while (false) | |||
3171 | dbgs() << "[AANoAliasCSArg] " << getAssociatedValue()do { } while (false) | |||
3172 | << " cannot be noalias as it is potentially captured\n")do { } while (false); | |||
3173 | return false; | |||
3174 | } | |||
3175 | } | |||
3176 | A.recordDependence(NoCaptureAA, *this, DepClassTy::OPTIONAL); | |||
3177 | ||||
3178 | // Check there is no other pointer argument which could alias with the | |||
3179 | // value passed at this call site. | |||
3180 | // TODO: AbstractCallSite | |||
3181 | const auto &CB = cast<CallBase>(getAnchorValue()); | |||
3182 | for (unsigned OtherArgNo = 0; OtherArgNo < CB.getNumArgOperands(); | |||
3183 | OtherArgNo++) | |||
3184 | if (mayAliasWithArgument(A, AAR, MemBehaviorAA, CB, OtherArgNo)) | |||
3185 | return false; | |||
3186 | ||||
3187 | return true; | |||
3188 | } | |||
3189 | ||||
3190 | /// See AbstractAttribute::updateImpl(...). | |||
3191 | ChangeStatus updateImpl(Attributor &A) override { | |||
3192 | // If the argument is readnone we are done as there are no accesses via the | |||
3193 | // argument. | |||
3194 | auto &MemBehaviorAA = | |||
3195 | A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), DepClassTy::NONE); | |||
3196 | if (MemBehaviorAA.isAssumedReadNone()) { | |||
3197 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); | |||
3198 | return ChangeStatus::UNCHANGED; | |||
3199 | } | |||
3200 | ||||
3201 | const IRPosition &VIRP = IRPosition::value(getAssociatedValue()); | |||
3202 | const auto &NoAliasAA = | |||
3203 | A.getAAFor<AANoAlias>(*this, VIRP, DepClassTy::NONE); | |||
3204 | ||||
3205 | AAResults *AAR = nullptr; | |||
3206 | if (isKnownNoAliasDueToNoAliasPreservation(A, AAR, MemBehaviorAA, | |||
3207 | NoAliasAA)) { | |||
3208 | LLVM_DEBUG(do { } while (false) | |||
3209 | dbgs() << "[AANoAlias] No-Alias deduced via no-alias preservation\n")do { } while (false); | |||
3210 | return ChangeStatus::UNCHANGED; | |||
3211 | } | |||
3212 | ||||
3213 | return indicatePessimisticFixpoint(); | |||
3214 | } | |||
3215 | ||||
3216 | /// See AbstractAttribute::trackStatistics() | |||
3217 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(noalias){ static llvm::Statistic NumIRCSArguments_noalias = {"attributor" , "NumIRCSArguments_noalias", ("Number of " "call site arguments" " marked '" "noalias" "'")};; ++(NumIRCSArguments_noalias); } } | |||
3218 | }; | |||
3219 | ||||
3220 | /// NoAlias attribute for function return value. | |||
3221 | struct AANoAliasReturned final : AANoAliasImpl { | |||
3222 | AANoAliasReturned(const IRPosition &IRP, Attributor &A) | |||
3223 | : AANoAliasImpl(IRP, A) {} | |||
3224 | ||||
3225 | /// See AbstractAttribute::initialize(...). | |||
3226 | void initialize(Attributor &A) override { | |||
3227 | AANoAliasImpl::initialize(A); | |||
3228 | Function *F = getAssociatedFunction(); | |||
3229 | if (!F || F->isDeclaration()) | |||
3230 | indicatePessimisticFixpoint(); | |||
3231 | } | |||
3232 | ||||
3233 | /// See AbstractAttribute::updateImpl(...). | |||
3234 | virtual ChangeStatus updateImpl(Attributor &A) override { | |||
3235 | ||||
3236 | auto CheckReturnValue = [&](Value &RV) -> bool { | |||
3237 | if (Constant *C = dyn_cast<Constant>(&RV)) | |||
3238 | if (C->isNullValue() || isa<UndefValue>(C)) | |||
3239 | return true; | |||
3240 | ||||
3241 | /// For now, we can only deduce noalias if we have call sites. | |||
3242 | /// FIXME: add more support. | |||
3243 | if (!isa<CallBase>(&RV)) | |||
3244 | return false; | |||
3245 | ||||
3246 | const IRPosition &RVPos = IRPosition::value(RV); | |||
3247 | const auto &NoAliasAA = | |||
3248 | A.getAAFor<AANoAlias>(*this, RVPos, DepClassTy::REQUIRED); | |||
3249 | if (!NoAliasAA.isAssumedNoAlias()) | |||
3250 | return false; | |||
3251 | ||||
3252 | const auto &NoCaptureAA = | |||
3253 | A.getAAFor<AANoCapture>(*this, RVPos, DepClassTy::REQUIRED); | |||
3254 | return NoCaptureAA.isAssumedNoCaptureMaybeReturned(); | |||
3255 | }; | |||
3256 | ||||
3257 | if (!A.checkForAllReturnedValues(CheckReturnValue, *this)) | |||
3258 | return indicatePessimisticFixpoint(); | |||
3259 | ||||
3260 | return ChangeStatus::UNCHANGED; | |||
3261 | } | |||
3262 | ||||
3263 | /// See AbstractAttribute::trackStatistics() | |||
3264 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(noalias){ static llvm::Statistic NumIRFunctionReturn_noalias = {"attributor" , "NumIRFunctionReturn_noalias", ("Number of " "function returns" " marked '" "noalias" "'")};; ++(NumIRFunctionReturn_noalias ); } } | |||
3265 | }; | |||
3266 | ||||
3267 | /// NoAlias attribute deduction for a call site return value. | |||
3268 | struct AANoAliasCallSiteReturned final : AANoAliasImpl { | |||
3269 | AANoAliasCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
3270 | : AANoAliasImpl(IRP, A) {} | |||
3271 | ||||
3272 | /// See AbstractAttribute::initialize(...). | |||
3273 | void initialize(Attributor &A) override { | |||
3274 | AANoAliasImpl::initialize(A); | |||
3275 | Function *F = getAssociatedFunction(); | |||
3276 | if (!F || F->isDeclaration()) | |||
3277 | indicatePessimisticFixpoint(); | |||
3278 | } | |||
3279 | ||||
3280 | /// See AbstractAttribute::updateImpl(...). | |||
3281 | ChangeStatus updateImpl(Attributor &A) override { | |||
3282 | // TODO: Once we have call site specific value information we can provide | |||
3283 | // call site specific liveness information and then it makes | |||
3284 | // sense to specialize attributes for call sites arguments instead of | |||
3285 | // redirecting requests to the callee argument. | |||
3286 | Function *F = getAssociatedFunction(); | |||
3287 | const IRPosition &FnPos = IRPosition::returned(*F); | |||
3288 | auto &FnAA = A.getAAFor<AANoAlias>(*this, FnPos, DepClassTy::REQUIRED); | |||
3289 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
3290 | } | |||
3291 | ||||
3292 | /// See AbstractAttribute::trackStatistics() | |||
3293 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(noalias){ static llvm::Statistic NumIRCSReturn_noalias = {"attributor" , "NumIRCSReturn_noalias", ("Number of " "call site returns" " marked '" "noalias" "'")};; ++(NumIRCSReturn_noalias); }; } | |||
3294 | }; | |||
3295 | ||||
3296 | /// -------------------AAIsDead Function Attribute----------------------- | |||
3297 | ||||
3298 | struct AAIsDeadValueImpl : public AAIsDead { | |||
3299 | AAIsDeadValueImpl(const IRPosition &IRP, Attributor &A) : AAIsDead(IRP, A) {} | |||
3300 | ||||
3301 | /// See AAIsDead::isAssumedDead(). | |||
3302 | bool isAssumedDead() const override { return isAssumed(IS_DEAD); } | |||
3303 | ||||
3304 | /// See AAIsDead::isKnownDead(). | |||
3305 | bool isKnownDead() const override { return isKnown(IS_DEAD); } | |||
3306 | ||||
3307 | /// See AAIsDead::isAssumedDead(BasicBlock *). | |||
3308 | bool isAssumedDead(const BasicBlock *BB) const override { return false; } | |||
3309 | ||||
3310 | /// See AAIsDead::isKnownDead(BasicBlock *). | |||
3311 | bool isKnownDead(const BasicBlock *BB) const override { return false; } | |||
3312 | ||||
3313 | /// See AAIsDead::isAssumedDead(Instruction *I). | |||
3314 | bool isAssumedDead(const Instruction *I) const override { | |||
3315 | return I == getCtxI() && isAssumedDead(); | |||
3316 | } | |||
3317 | ||||
3318 | /// See AAIsDead::isKnownDead(Instruction *I). | |||
3319 | bool isKnownDead(const Instruction *I) const override { | |||
3320 | return isAssumedDead(I) && isKnownDead(); | |||
3321 | } | |||
3322 | ||||
3323 | /// See AbstractAttribute::getAsStr(). | |||
3324 | const std::string getAsStr() const override { | |||
3325 | return isAssumedDead() ? "assumed-dead" : "assumed-live"; | |||
3326 | } | |||
3327 | ||||
3328 | /// Check if all uses are assumed dead. | |||
3329 | bool areAllUsesAssumedDead(Attributor &A, Value &V) { | |||
3330 | // Callers might not check the type, void has no uses. | |||
3331 | if (V.getType()->isVoidTy()) | |||
3332 | return true; | |||
3333 | ||||
3334 | // If we replace a value with a constant there are no uses left afterwards. | |||
3335 | if (!isa<Constant>(V)) { | |||
3336 | bool UsedAssumedInformation = false; | |||
3337 | Optional<Constant *> C = | |||
3338 | A.getAssumedConstant(V, *this, UsedAssumedInformation); | |||
3339 | if (!C.hasValue() || *C) | |||
3340 | return true; | |||
3341 | } | |||
3342 | ||||
3343 | auto UsePred = [&](const Use &U, bool &Follow) { return false; }; | |||
3344 | // Explicitly set the dependence class to required because we want a long | |||
3345 | // chain of N dependent instructions to be considered live as soon as one is | |||
3346 | // without going through N update cycles. This is not required for | |||
3347 | // correctness. | |||
3348 | return A.checkForAllUses(UsePred, *this, V, /* CheckBBLivenessOnly */ false, | |||
3349 | DepClassTy::REQUIRED); | |||
3350 | } | |||
3351 | ||||
3352 | /// Determine if \p I is assumed to be side-effect free. | |||
3353 | bool isAssumedSideEffectFree(Attributor &A, Instruction *I) { | |||
3354 | if (!I || wouldInstructionBeTriviallyDead(I)) | |||
3355 | return true; | |||
3356 | ||||
3357 | auto *CB = dyn_cast<CallBase>(I); | |||
3358 | if (!CB || isa<IntrinsicInst>(CB)) | |||
3359 | return false; | |||
3360 | ||||
3361 | const IRPosition &CallIRP = IRPosition::callsite_function(*CB); | |||
3362 | const auto &NoUnwindAA = | |||
3363 | A.getAndUpdateAAFor<AANoUnwind>(*this, CallIRP, DepClassTy::NONE); | |||
3364 | if (!NoUnwindAA.isAssumedNoUnwind()) | |||
3365 | return false; | |||
3366 | if (!NoUnwindAA.isKnownNoUnwind()) | |||
3367 | A.recordDependence(NoUnwindAA, *this, DepClassTy::OPTIONAL); | |||
3368 | ||||
3369 | const auto &MemBehaviorAA = | |||
3370 | A.getAndUpdateAAFor<AAMemoryBehavior>(*this, CallIRP, DepClassTy::NONE); | |||
3371 | if (MemBehaviorAA.isAssumedReadOnly()) { | |||
3372 | if (!MemBehaviorAA.isKnownReadOnly()) | |||
3373 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); | |||
3374 | return true; | |||
3375 | } | |||
3376 | return false; | |||
3377 | } | |||
3378 | }; | |||
3379 | ||||
3380 | struct AAIsDeadFloating : public AAIsDeadValueImpl { | |||
3381 | AAIsDeadFloating(const IRPosition &IRP, Attributor &A) | |||
3382 | : AAIsDeadValueImpl(IRP, A) {} | |||
3383 | ||||
3384 | /// See AbstractAttribute::initialize(...). | |||
3385 | void initialize(Attributor &A) override { | |||
3386 | if (isa<UndefValue>(getAssociatedValue())) { | |||
3387 | indicatePessimisticFixpoint(); | |||
3388 | return; | |||
3389 | } | |||
3390 | ||||
3391 | Instruction *I = dyn_cast<Instruction>(&getAssociatedValue()); | |||
3392 | if (!isAssumedSideEffectFree(A, I)) { | |||
3393 | if (!isa_and_nonnull<StoreInst>(I)) | |||
3394 | indicatePessimisticFixpoint(); | |||
3395 | else | |||
3396 | removeAssumedBits(HAS_NO_EFFECT); | |||
3397 | } | |||
3398 | } | |||
3399 | ||||
3400 | bool isDeadStore(Attributor &A, StoreInst &SI) { | |||
3401 | bool UsedAssumedInformation = false; | |||
3402 | SmallSetVector<Value *, 4> PotentialCopies; | |||
3403 | if (!AA::getPotentialCopiesOfStoredValue(A, SI, PotentialCopies, *this, | |||
3404 | UsedAssumedInformation)) | |||
3405 | return false; | |||
3406 | return llvm::all_of(PotentialCopies, [&](Value *V) { | |||
3407 | return A.isAssumedDead(IRPosition::value(*V), this, nullptr, | |||
3408 | UsedAssumedInformation); | |||
3409 | }); | |||
3410 | } | |||
3411 | ||||
3412 | /// See AbstractAttribute::updateImpl(...). | |||
3413 | ChangeStatus updateImpl(Attributor &A) override { | |||
3414 | Instruction *I = dyn_cast<Instruction>(&getAssociatedValue()); | |||
3415 | if (auto *SI = dyn_cast_or_null<StoreInst>(I)) { | |||
3416 | if (!isDeadStore(A, *SI)) | |||
3417 | return indicatePessimisticFixpoint(); | |||
3418 | } else { | |||
3419 | if (!isAssumedSideEffectFree(A, I)) | |||
3420 | return indicatePessimisticFixpoint(); | |||
3421 | if (!areAllUsesAssumedDead(A, getAssociatedValue())) | |||
3422 | return indicatePessimisticFixpoint(); | |||
3423 | } | |||
3424 | return ChangeStatus::UNCHANGED; | |||
3425 | } | |||
3426 | ||||
3427 | /// See AbstractAttribute::manifest(...). | |||
3428 | ChangeStatus manifest(Attributor &A) override { | |||
3429 | Value &V = getAssociatedValue(); | |||
3430 | if (auto *I = dyn_cast<Instruction>(&V)) { | |||
3431 | // If we get here we basically know the users are all dead. We check if | |||
3432 | // isAssumedSideEffectFree returns true here again because it might not be | |||
3433 | // the case and only the users are dead but the instruction (=call) is | |||
3434 | // still needed. | |||
3435 | if (isa<StoreInst>(I) || | |||
3436 | (isAssumedSideEffectFree(A, I) && !isa<InvokeInst>(I))) { | |||
3437 | A.deleteAfterManifest(*I); | |||
3438 | return ChangeStatus::CHANGED; | |||
3439 | } | |||
3440 | } | |||
3441 | if (V.use_empty()) | |||
3442 | return ChangeStatus::UNCHANGED; | |||
3443 | ||||
3444 | bool UsedAssumedInformation = false; | |||
3445 | Optional<Constant *> C = | |||
3446 | A.getAssumedConstant(V, *this, UsedAssumedInformation); | |||
3447 | if (C.hasValue() && C.getValue()) | |||
3448 | return ChangeStatus::UNCHANGED; | |||
3449 | ||||
3450 | // Replace the value with undef as it is dead but keep droppable uses around | |||
3451 | // as they provide information we don't want to give up on just yet. | |||
3452 | UndefValue &UV = *UndefValue::get(V.getType()); | |||
3453 | bool AnyChange = | |||
3454 | A.changeValueAfterManifest(V, UV, /* ChangeDropppable */ false); | |||
3455 | return AnyChange ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; | |||
3456 | } | |||
3457 | ||||
3458 | /// See AbstractAttribute::trackStatistics() | |||
3459 | void trackStatistics() const override { | |||
3460 | STATS_DECLTRACK_FLOATING_ATTR(IsDead){ static llvm::Statistic NumIRFloating_IsDead = {"attributor" , "NumIRFloating_IsDead", ("Number of floating values known to be '" "IsDead" "'")};; ++(NumIRFloating_IsDead); } | |||
3461 | } | |||
3462 | }; | |||
3463 | ||||
3464 | struct AAIsDeadArgument : public AAIsDeadFloating { | |||
3465 | AAIsDeadArgument(const IRPosition &IRP, Attributor &A) | |||
3466 | : AAIsDeadFloating(IRP, A) {} | |||
3467 | ||||
3468 | /// See AbstractAttribute::initialize(...). | |||
3469 | void initialize(Attributor &A) override { | |||
3470 | if (!A.isFunctionIPOAmendable(*getAnchorScope())) | |||
3471 | indicatePessimisticFixpoint(); | |||
3472 | } | |||
3473 | ||||
3474 | /// See AbstractAttribute::manifest(...). | |||
3475 | ChangeStatus manifest(Attributor &A) override { | |||
3476 | ChangeStatus Changed = AAIsDeadFloating::manifest(A); | |||
3477 | Argument &Arg = *getAssociatedArgument(); | |||
3478 | if (A.isValidFunctionSignatureRewrite(Arg, /* ReplacementTypes */ {})) | |||
3479 | if (A.registerFunctionSignatureRewrite( | |||
3480 | Arg, /* ReplacementTypes */ {}, | |||
3481 | Attributor::ArgumentReplacementInfo::CalleeRepairCBTy{}, | |||
3482 | Attributor::ArgumentReplacementInfo::ACSRepairCBTy{})) { | |||
3483 | Arg.dropDroppableUses(); | |||
3484 | return ChangeStatus::CHANGED; | |||
3485 | } | |||
3486 | return Changed; | |||
3487 | } | |||
3488 | ||||
3489 | /// See AbstractAttribute::trackStatistics() | |||
3490 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(IsDead){ static llvm::Statistic NumIRArguments_IsDead = {"attributor" , "NumIRArguments_IsDead", ("Number of " "arguments" " marked '" "IsDead" "'")};; ++(NumIRArguments_IsDead); } } | |||
3491 | }; | |||
3492 | ||||
3493 | struct AAIsDeadCallSiteArgument : public AAIsDeadValueImpl { | |||
3494 | AAIsDeadCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
3495 | : AAIsDeadValueImpl(IRP, A) {} | |||
3496 | ||||
3497 | /// See AbstractAttribute::initialize(...). | |||
3498 | void initialize(Attributor &A) override { | |||
3499 | if (isa<UndefValue>(getAssociatedValue())) | |||
3500 | indicatePessimisticFixpoint(); | |||
3501 | } | |||
3502 | ||||
3503 | /// See AbstractAttribute::updateImpl(...). | |||
3504 | ChangeStatus updateImpl(Attributor &A) override { | |||
3505 | // TODO: Once we have call site specific value information we can provide | |||
3506 | // call site specific liveness information and then it makes | |||
3507 | // sense to specialize attributes for call sites arguments instead of | |||
3508 | // redirecting requests to the callee argument. | |||
3509 | Argument *Arg = getAssociatedArgument(); | |||
3510 | if (!Arg) | |||
3511 | return indicatePessimisticFixpoint(); | |||
3512 | const IRPosition &ArgPos = IRPosition::argument(*Arg); | |||
3513 | auto &ArgAA = A.getAAFor<AAIsDead>(*this, ArgPos, DepClassTy::REQUIRED); | |||
3514 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); | |||
3515 | } | |||
3516 | ||||
3517 | /// See AbstractAttribute::manifest(...). | |||
3518 | ChangeStatus manifest(Attributor &A) override { | |||
3519 | CallBase &CB = cast<CallBase>(getAnchorValue()); | |||
3520 | Use &U = CB.getArgOperandUse(getCallSiteArgNo()); | |||
3521 | assert(!isa<UndefValue>(U.get()) &&((void)0) | |||
3522 | "Expected undef values to be filtered out!")((void)0); | |||
3523 | UndefValue &UV = *UndefValue::get(U->getType()); | |||
3524 | if (A.changeUseAfterManifest(U, UV)) | |||
3525 | return ChangeStatus::CHANGED; | |||
3526 | return ChangeStatus::UNCHANGED; | |||
3527 | } | |||
3528 | ||||
3529 | /// See AbstractAttribute::trackStatistics() | |||
3530 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(IsDead){ static llvm::Statistic NumIRCSArguments_IsDead = {"attributor" , "NumIRCSArguments_IsDead", ("Number of " "call site arguments" " marked '" "IsDead" "'")};; ++(NumIRCSArguments_IsDead); } } | |||
3531 | }; | |||
3532 | ||||
3533 | struct AAIsDeadCallSiteReturned : public AAIsDeadFloating { | |||
3534 | AAIsDeadCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
3535 | : AAIsDeadFloating(IRP, A), IsAssumedSideEffectFree(true) {} | |||
3536 | ||||
3537 | /// See AAIsDead::isAssumedDead(). | |||
3538 | bool isAssumedDead() const override { | |||
3539 | return AAIsDeadFloating::isAssumedDead() && IsAssumedSideEffectFree; | |||
3540 | } | |||
3541 | ||||
3542 | /// See AbstractAttribute::initialize(...). | |||
3543 | void initialize(Attributor &A) override { | |||
3544 | if (isa<UndefValue>(getAssociatedValue())) { | |||
3545 | indicatePessimisticFixpoint(); | |||
3546 | return; | |||
3547 | } | |||
3548 | ||||
3549 | // We track this separately as a secondary state. | |||
3550 | IsAssumedSideEffectFree = isAssumedSideEffectFree(A, getCtxI()); | |||
3551 | } | |||
3552 | ||||
3553 | /// See AbstractAttribute::updateImpl(...). | |||
3554 | ChangeStatus updateImpl(Attributor &A) override { | |||
3555 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
3556 | if (IsAssumedSideEffectFree && !isAssumedSideEffectFree(A, getCtxI())) { | |||
3557 | IsAssumedSideEffectFree = false; | |||
3558 | Changed = ChangeStatus::CHANGED; | |||
3559 | } | |||
3560 | if (!areAllUsesAssumedDead(A, getAssociatedValue())) | |||
3561 | return indicatePessimisticFixpoint(); | |||
3562 | return Changed; | |||
3563 | } | |||
3564 | ||||
3565 | /// See AbstractAttribute::trackStatistics() | |||
3566 | void trackStatistics() const override { | |||
3567 | if (IsAssumedSideEffectFree) | |||
3568 | STATS_DECLTRACK_CSRET_ATTR(IsDead){ static llvm::Statistic NumIRCSReturn_IsDead = {"attributor" , "NumIRCSReturn_IsDead", ("Number of " "call site returns" " marked '" "IsDead" "'")};; ++(NumIRCSReturn_IsDead); } | |||
3569 | else | |||
3570 | STATS_DECLTRACK_CSRET_ATTR(UnusedResult){ static llvm::Statistic NumIRCSReturn_UnusedResult = {"attributor" , "NumIRCSReturn_UnusedResult", ("Number of " "call site returns" " marked '" "UnusedResult" "'")};; ++(NumIRCSReturn_UnusedResult ); } | |||
3571 | } | |||
3572 | ||||
3573 | /// See AbstractAttribute::getAsStr(). | |||
3574 | const std::string getAsStr() const override { | |||
3575 | return isAssumedDead() | |||
3576 | ? "assumed-dead" | |||
3577 | : (getAssumed() ? "assumed-dead-users" : "assumed-live"); | |||
3578 | } | |||
3579 | ||||
3580 | private: | |||
3581 | bool IsAssumedSideEffectFree; | |||
3582 | }; | |||
3583 | ||||
3584 | struct AAIsDeadReturned : public AAIsDeadValueImpl { | |||
3585 | AAIsDeadReturned(const IRPosition &IRP, Attributor &A) | |||
3586 | : AAIsDeadValueImpl(IRP, A) {} | |||
3587 | ||||
3588 | /// See AbstractAttribute::updateImpl(...). | |||
3589 | ChangeStatus updateImpl(Attributor &A) override { | |||
3590 | ||||
3591 | bool UsedAssumedInformation = false; | |||
3592 | A.checkForAllInstructions([](Instruction &) { return true; }, *this, | |||
3593 | {Instruction::Ret}, UsedAssumedInformation); | |||
3594 | ||||
3595 | auto PredForCallSite = [&](AbstractCallSite ACS) { | |||
3596 | if (ACS.isCallbackCall() || !ACS.getInstruction()) | |||
3597 | return false; | |||
3598 | return areAllUsesAssumedDead(A, *ACS.getInstruction()); | |||
3599 | }; | |||
3600 | ||||
3601 | bool AllCallSitesKnown; | |||
3602 | if (!A.checkForAllCallSites(PredForCallSite, *this, true, | |||
3603 | AllCallSitesKnown)) | |||
3604 | return indicatePessimisticFixpoint(); | |||
3605 | ||||
3606 | return ChangeStatus::UNCHANGED; | |||
3607 | } | |||
3608 | ||||
3609 | /// See AbstractAttribute::manifest(...). | |||
3610 | ChangeStatus manifest(Attributor &A) override { | |||
3611 | // TODO: Rewrite the signature to return void? | |||
3612 | bool AnyChange = false; | |||
3613 | UndefValue &UV = *UndefValue::get(getAssociatedFunction()->getReturnType()); | |||
3614 | auto RetInstPred = [&](Instruction &I) { | |||
3615 | ReturnInst &RI = cast<ReturnInst>(I); | |||
3616 | if (!isa<UndefValue>(RI.getReturnValue())) | |||
3617 | AnyChange |= A.changeUseAfterManifest(RI.getOperandUse(0), UV); | |||
3618 | return true; | |||
3619 | }; | |||
3620 | bool UsedAssumedInformation = false; | |||
3621 | A.checkForAllInstructions(RetInstPred, *this, {Instruction::Ret}, | |||
3622 | UsedAssumedInformation); | |||
3623 | return AnyChange ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; | |||
3624 | } | |||
3625 | ||||
3626 | /// See AbstractAttribute::trackStatistics() | |||
3627 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(IsDead){ static llvm::Statistic NumIRFunctionReturn_IsDead = {"attributor" , "NumIRFunctionReturn_IsDead", ("Number of " "function returns" " marked '" "IsDead" "'")};; ++(NumIRFunctionReturn_IsDead); } } | |||
3628 | }; | |||
3629 | ||||
3630 | struct AAIsDeadFunction : public AAIsDead { | |||
3631 | AAIsDeadFunction(const IRPosition &IRP, Attributor &A) : AAIsDead(IRP, A) {} | |||
3632 | ||||
3633 | /// See AbstractAttribute::initialize(...). | |||
3634 | void initialize(Attributor &A) override { | |||
3635 | const Function *F = getAnchorScope(); | |||
3636 | if (F && !F->isDeclaration()) { | |||
3637 | // We only want to compute liveness once. If the function is not part of | |||
3638 | // the SCC, skip it. | |||
3639 | if (A.isRunOn(*const_cast<Function *>(F))) { | |||
3640 | ToBeExploredFrom.insert(&F->getEntryBlock().front()); | |||
3641 | assumeLive(A, F->getEntryBlock()); | |||
3642 | } else { | |||
3643 | indicatePessimisticFixpoint(); | |||
3644 | } | |||
3645 | } | |||
3646 | } | |||
3647 | ||||
3648 | /// See AbstractAttribute::getAsStr(). | |||
3649 | const std::string getAsStr() const override { | |||
3650 | return "Live[#BB " + std::to_string(AssumedLiveBlocks.size()) + "/" + | |||
3651 | std::to_string(getAnchorScope()->size()) + "][#TBEP " + | |||
3652 | std::to_string(ToBeExploredFrom.size()) + "][#KDE " + | |||
3653 | std::to_string(KnownDeadEnds.size()) + "]"; | |||
3654 | } | |||
3655 | ||||
3656 | /// See AbstractAttribute::manifest(...). | |||
3657 | ChangeStatus manifest(Attributor &A) override { | |||
3658 | assert(getState().isValidState() &&((void)0) | |||
3659 | "Attempted to manifest an invalid state!")((void)0); | |||
3660 | ||||
3661 | ChangeStatus HasChanged = ChangeStatus::UNCHANGED; | |||
3662 | Function &F = *getAnchorScope(); | |||
3663 | ||||
3664 | if (AssumedLiveBlocks.empty()) { | |||
3665 | A.deleteAfterManifest(F); | |||
3666 | return ChangeStatus::CHANGED; | |||
3667 | } | |||
3668 | ||||
3669 | // Flag to determine if we can change an invoke to a call assuming the | |||
3670 | // callee is nounwind. This is not possible if the personality of the | |||
3671 | // function allows to catch asynchronous exceptions. | |||
3672 | bool Invoke2CallAllowed = !mayCatchAsynchronousExceptions(F); | |||
3673 | ||||
3674 | KnownDeadEnds.set_union(ToBeExploredFrom); | |||
3675 | for (const Instruction *DeadEndI : KnownDeadEnds) { | |||
3676 | auto *CB = dyn_cast<CallBase>(DeadEndI); | |||
3677 | if (!CB) | |||
3678 | continue; | |||
3679 | const auto &NoReturnAA = A.getAndUpdateAAFor<AANoReturn>( | |||
3680 | *this, IRPosition::callsite_function(*CB), DepClassTy::OPTIONAL); | |||
3681 | bool MayReturn = !NoReturnAA.isAssumedNoReturn(); | |||
3682 | if (MayReturn && (!Invoke2CallAllowed || !isa<InvokeInst>(CB))) | |||
3683 | continue; | |||
3684 | ||||
3685 | if (auto *II = dyn_cast<InvokeInst>(DeadEndI)) | |||
3686 | A.registerInvokeWithDeadSuccessor(const_cast<InvokeInst &>(*II)); | |||
3687 | else | |||
3688 | A.changeToUnreachableAfterManifest( | |||
3689 | const_cast<Instruction *>(DeadEndI->getNextNode())); | |||
3690 | HasChanged = ChangeStatus::CHANGED; | |||
3691 | } | |||
3692 | ||||
3693 | STATS_DECL(AAIsDead, BasicBlock, "Number of dead basic blocks deleted.")static llvm::Statistic NumIRBasicBlock_AAIsDead = {"attributor" , "NumIRBasicBlock_AAIsDead", "Number of dead basic blocks deleted." };;; | |||
3694 | for (BasicBlock &BB : F) | |||
3695 | if (!AssumedLiveBlocks.count(&BB)) { | |||
3696 | A.deleteAfterManifest(BB); | |||
3697 | ++BUILD_STAT_NAME(AAIsDead, BasicBlock)NumIRBasicBlock_AAIsDead; | |||
3698 | } | |||
3699 | ||||
3700 | return HasChanged; | |||
3701 | } | |||
3702 | ||||
3703 | /// See AbstractAttribute::updateImpl(...). | |||
3704 | ChangeStatus updateImpl(Attributor &A) override; | |||
3705 | ||||
3706 | bool isEdgeDead(const BasicBlock *From, const BasicBlock *To) const override { | |||
3707 | return !AssumedLiveEdges.count(std::make_pair(From, To)); | |||
3708 | } | |||
3709 | ||||
3710 | /// See AbstractAttribute::trackStatistics() | |||
3711 | void trackStatistics() const override {} | |||
3712 | ||||
3713 | /// Returns true if the function is assumed dead. | |||
3714 | bool isAssumedDead() const override { return false; } | |||
3715 | ||||
3716 | /// See AAIsDead::isKnownDead(). | |||
3717 | bool isKnownDead() const override { return false; } | |||
3718 | ||||
3719 | /// See AAIsDead::isAssumedDead(BasicBlock *). | |||
3720 | bool isAssumedDead(const BasicBlock *BB) const override { | |||
3721 | assert(BB->getParent() == getAnchorScope() &&((void)0) | |||
3722 | "BB must be in the same anchor scope function.")((void)0); | |||
3723 | ||||
3724 | if (!getAssumed()) | |||
3725 | return false; | |||
3726 | return !AssumedLiveBlocks.count(BB); | |||
3727 | } | |||
3728 | ||||
3729 | /// See AAIsDead::isKnownDead(BasicBlock *). | |||
3730 | bool isKnownDead(const BasicBlock *BB) const override { | |||
3731 | return getKnown() && isAssumedDead(BB); | |||
3732 | } | |||
3733 | ||||
3734 | /// See AAIsDead::isAssumed(Instruction *I). | |||
3735 | bool isAssumedDead(const Instruction *I) const override { | |||
3736 | assert(I->getParent()->getParent() == getAnchorScope() &&((void)0) | |||
3737 | "Instruction must be in the same anchor scope function.")((void)0); | |||
3738 | ||||
3739 | if (!getAssumed()) | |||
3740 | return false; | |||
3741 | ||||
3742 | // If it is not in AssumedLiveBlocks then it for sure dead. | |||
3743 | // Otherwise, it can still be after noreturn call in a live block. | |||
3744 | if (!AssumedLiveBlocks.count(I->getParent())) | |||
3745 | return true; | |||
3746 | ||||
3747 | // If it is not after a liveness barrier it is live. | |||
3748 | const Instruction *PrevI = I->getPrevNode(); | |||
3749 | while (PrevI) { | |||
3750 | if (KnownDeadEnds.count(PrevI) || ToBeExploredFrom.count(PrevI)) | |||
3751 | return true; | |||
3752 | PrevI = PrevI->getPrevNode(); | |||
3753 | } | |||
3754 | return false; | |||
3755 | } | |||
3756 | ||||
3757 | /// See AAIsDead::isKnownDead(Instruction *I). | |||
3758 | bool isKnownDead(const Instruction *I) const override { | |||
3759 | return getKnown() && isAssumedDead(I); | |||
3760 | } | |||
3761 | ||||
3762 | /// Assume \p BB is (partially) live now and indicate to the Attributor \p A | |||
3763 | /// that internal function called from \p BB should now be looked at. | |||
3764 | bool assumeLive(Attributor &A, const BasicBlock &BB) { | |||
3765 | if (!AssumedLiveBlocks.insert(&BB).second) | |||
3766 | return false; | |||
3767 | ||||
3768 | // We assume that all of BB is (probably) live now and if there are calls to | |||
3769 | // internal functions we will assume that those are now live as well. This | |||
3770 | // is a performance optimization for blocks with calls to a lot of internal | |||
3771 | // functions. It can however cause dead functions to be treated as live. | |||
3772 | for (const Instruction &I : BB) | |||
3773 | if (const auto *CB = dyn_cast<CallBase>(&I)) | |||
3774 | if (const Function *F = CB->getCalledFunction()) | |||
3775 | if (F->hasLocalLinkage()) | |||
3776 | A.markLiveInternalFunction(*F); | |||
3777 | return true; | |||
3778 | } | |||
3779 | ||||
3780 | /// Collection of instructions that need to be explored again, e.g., we | |||
3781 | /// did assume they do not transfer control to (one of their) successors. | |||
3782 | SmallSetVector<const Instruction *, 8> ToBeExploredFrom; | |||
3783 | ||||
3784 | /// Collection of instructions that are known to not transfer control. | |||
3785 | SmallSetVector<const Instruction *, 8> KnownDeadEnds; | |||
3786 | ||||
3787 | /// Collection of all assumed live edges | |||
3788 | DenseSet<std::pair<const BasicBlock *, const BasicBlock *>> AssumedLiveEdges; | |||
3789 | ||||
3790 | /// Collection of all assumed live BasicBlocks. | |||
3791 | DenseSet<const BasicBlock *> AssumedLiveBlocks; | |||
3792 | }; | |||
3793 | ||||
3794 | static bool | |||
3795 | identifyAliveSuccessors(Attributor &A, const CallBase &CB, | |||
3796 | AbstractAttribute &AA, | |||
3797 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { | |||
3798 | const IRPosition &IPos = IRPosition::callsite_function(CB); | |||
3799 | ||||
3800 | const auto &NoReturnAA = | |||
3801 | A.getAndUpdateAAFor<AANoReturn>(AA, IPos, DepClassTy::OPTIONAL); | |||
3802 | if (NoReturnAA.isAssumedNoReturn()) | |||
3803 | return !NoReturnAA.isKnownNoReturn(); | |||
3804 | if (CB.isTerminator()) | |||
3805 | AliveSuccessors.push_back(&CB.getSuccessor(0)->front()); | |||
3806 | else | |||
3807 | AliveSuccessors.push_back(CB.getNextNode()); | |||
3808 | return false; | |||
3809 | } | |||
3810 | ||||
3811 | static bool | |||
3812 | identifyAliveSuccessors(Attributor &A, const InvokeInst &II, | |||
3813 | AbstractAttribute &AA, | |||
3814 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { | |||
3815 | bool UsedAssumedInformation = | |||
3816 | identifyAliveSuccessors(A, cast<CallBase>(II), AA, AliveSuccessors); | |||
3817 | ||||
3818 | // First, determine if we can change an invoke to a call assuming the | |||
3819 | // callee is nounwind. This is not possible if the personality of the | |||
3820 | // function allows to catch asynchronous exceptions. | |||
3821 | if (AAIsDeadFunction::mayCatchAsynchronousExceptions(*II.getFunction())) { | |||
3822 | AliveSuccessors.push_back(&II.getUnwindDest()->front()); | |||
3823 | } else { | |||
3824 | const IRPosition &IPos = IRPosition::callsite_function(II); | |||
3825 | const auto &AANoUnw = | |||
3826 | A.getAndUpdateAAFor<AANoUnwind>(AA, IPos, DepClassTy::OPTIONAL); | |||
3827 | if (AANoUnw.isAssumedNoUnwind()) { | |||
3828 | UsedAssumedInformation |= !AANoUnw.isKnownNoUnwind(); | |||
3829 | } else { | |||
3830 | AliveSuccessors.push_back(&II.getUnwindDest()->front()); | |||
3831 | } | |||
3832 | } | |||
3833 | return UsedAssumedInformation; | |||
3834 | } | |||
3835 | ||||
3836 | static bool | |||
3837 | identifyAliveSuccessors(Attributor &A, const BranchInst &BI, | |||
3838 | AbstractAttribute &AA, | |||
3839 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { | |||
3840 | bool UsedAssumedInformation = false; | |||
3841 | if (BI.getNumSuccessors() == 1) { | |||
3842 | AliveSuccessors.push_back(&BI.getSuccessor(0)->front()); | |||
3843 | } else { | |||
3844 | Optional<Constant *> C = | |||
3845 | A.getAssumedConstant(*BI.getCondition(), AA, UsedAssumedInformation); | |||
3846 | if (!C.hasValue() || isa_and_nonnull<UndefValue>(C.getValue())) { | |||
3847 | // No value yet, assume both edges are dead. | |||
3848 | } else if (isa_and_nonnull<ConstantInt>(*C)) { | |||
3849 | const BasicBlock *SuccBB = | |||
3850 | BI.getSuccessor(1 - cast<ConstantInt>(*C)->getValue().getZExtValue()); | |||
3851 | AliveSuccessors.push_back(&SuccBB->front()); | |||
3852 | } else { | |||
3853 | AliveSuccessors.push_back(&BI.getSuccessor(0)->front()); | |||
3854 | AliveSuccessors.push_back(&BI.getSuccessor(1)->front()); | |||
3855 | UsedAssumedInformation = false; | |||
3856 | } | |||
3857 | } | |||
3858 | return UsedAssumedInformation; | |||
3859 | } | |||
3860 | ||||
3861 | static bool | |||
3862 | identifyAliveSuccessors(Attributor &A, const SwitchInst &SI, | |||
3863 | AbstractAttribute &AA, | |||
3864 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { | |||
3865 | bool UsedAssumedInformation = false; | |||
3866 | Optional<Constant *> C = | |||
3867 | A.getAssumedConstant(*SI.getCondition(), AA, UsedAssumedInformation); | |||
3868 | if (!C.hasValue() || isa_and_nonnull<UndefValue>(C.getValue())) { | |||
3869 | // No value yet, assume all edges are dead. | |||
3870 | } else if (isa_and_nonnull<ConstantInt>(C.getValue())) { | |||
3871 | for (auto &CaseIt : SI.cases()) { | |||
3872 | if (CaseIt.getCaseValue() == C.getValue()) { | |||
3873 | AliveSuccessors.push_back(&CaseIt.getCaseSuccessor()->front()); | |||
3874 | return UsedAssumedInformation; | |||
3875 | } | |||
3876 | } | |||
3877 | AliveSuccessors.push_back(&SI.getDefaultDest()->front()); | |||
3878 | return UsedAssumedInformation; | |||
3879 | } else { | |||
3880 | for (const BasicBlock *SuccBB : successors(SI.getParent())) | |||
3881 | AliveSuccessors.push_back(&SuccBB->front()); | |||
3882 | } | |||
3883 | return UsedAssumedInformation; | |||
3884 | } | |||
3885 | ||||
3886 | ChangeStatus AAIsDeadFunction::updateImpl(Attributor &A) { | |||
3887 | ChangeStatus Change = ChangeStatus::UNCHANGED; | |||
3888 | ||||
3889 | LLVM_DEBUG(dbgs() << "[AAIsDead] Live [" << AssumedLiveBlocks.size() << "/"do { } while (false) | |||
3890 | << getAnchorScope()->size() << "] BBs and "do { } while (false) | |||
3891 | << ToBeExploredFrom.size() << " exploration points and "do { } while (false) | |||
3892 | << KnownDeadEnds.size() << " known dead ends\n")do { } while (false); | |||
3893 | ||||
3894 | // Copy and clear the list of instructions we need to explore from. It is | |||
3895 | // refilled with instructions the next update has to look at. | |||
3896 | SmallVector<const Instruction *, 8> Worklist(ToBeExploredFrom.begin(), | |||
3897 | ToBeExploredFrom.end()); | |||
3898 | decltype(ToBeExploredFrom) NewToBeExploredFrom; | |||
3899 | ||||
3900 | SmallVector<const Instruction *, 8> AliveSuccessors; | |||
3901 | while (!Worklist.empty()) { | |||
3902 | const Instruction *I = Worklist.pop_back_val(); | |||
3903 | LLVM_DEBUG(dbgs() << "[AAIsDead] Exploration inst: " << *I << "\n")do { } while (false); | |||
3904 | ||||
3905 | // Fast forward for uninteresting instructions. We could look for UB here | |||
3906 | // though. | |||
3907 | while (!I->isTerminator() && !isa<CallBase>(I)) | |||
3908 | I = I->getNextNode(); | |||
3909 | ||||
3910 | AliveSuccessors.clear(); | |||
3911 | ||||
3912 | bool UsedAssumedInformation = false; | |||
3913 | switch (I->getOpcode()) { | |||
3914 | // TODO: look for (assumed) UB to backwards propagate "deadness". | |||
3915 | default: | |||
3916 | assert(I->isTerminator() &&((void)0) | |||
3917 | "Expected non-terminators to be handled already!")((void)0); | |||
3918 | for (const BasicBlock *SuccBB : successors(I->getParent())) | |||
3919 | AliveSuccessors.push_back(&SuccBB->front()); | |||
3920 | break; | |||
3921 | case Instruction::Call: | |||
3922 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<CallInst>(*I), | |||
3923 | *this, AliveSuccessors); | |||
3924 | break; | |||
3925 | case Instruction::Invoke: | |||
3926 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<InvokeInst>(*I), | |||
3927 | *this, AliveSuccessors); | |||
3928 | break; | |||
3929 | case Instruction::Br: | |||
3930 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<BranchInst>(*I), | |||
3931 | *this, AliveSuccessors); | |||
3932 | break; | |||
3933 | case Instruction::Switch: | |||
3934 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<SwitchInst>(*I), | |||
3935 | *this, AliveSuccessors); | |||
3936 | break; | |||
3937 | } | |||
3938 | ||||
3939 | if (UsedAssumedInformation) { | |||
3940 | NewToBeExploredFrom.insert(I); | |||
3941 | } else if (AliveSuccessors.empty() || | |||
3942 | (I->isTerminator() && | |||
3943 | AliveSuccessors.size() < I->getNumSuccessors())) { | |||
3944 | if (KnownDeadEnds.insert(I)) | |||
3945 | Change = ChangeStatus::CHANGED; | |||
3946 | } | |||
3947 | ||||
3948 | LLVM_DEBUG(dbgs() << "[AAIsDead] #AliveSuccessors: "do { } while (false) | |||
3949 | << AliveSuccessors.size() << " UsedAssumedInformation: "do { } while (false) | |||
3950 | << UsedAssumedInformation << "\n")do { } while (false); | |||
3951 | ||||
3952 | for (const Instruction *AliveSuccessor : AliveSuccessors) { | |||
3953 | if (!I->isTerminator()) { | |||
3954 | assert(AliveSuccessors.size() == 1 &&((void)0) | |||
3955 | "Non-terminator expected to have a single successor!")((void)0); | |||
3956 | Worklist.push_back(AliveSuccessor); | |||
3957 | } else { | |||
3958 | // record the assumed live edge | |||
3959 | auto Edge = std::make_pair(I->getParent(), AliveSuccessor->getParent()); | |||
3960 | if (AssumedLiveEdges.insert(Edge).second) | |||
3961 | Change = ChangeStatus::CHANGED; | |||
3962 | if (assumeLive(A, *AliveSuccessor->getParent())) | |||
3963 | Worklist.push_back(AliveSuccessor); | |||
3964 | } | |||
3965 | } | |||
3966 | } | |||
3967 | ||||
3968 | // Check if the content of ToBeExploredFrom changed, ignore the order. | |||
3969 | if (NewToBeExploredFrom.size() != ToBeExploredFrom.size() || | |||
3970 | llvm::any_of(NewToBeExploredFrom, [&](const Instruction *I) { | |||
3971 | return !ToBeExploredFrom.count(I); | |||
3972 | })) { | |||
3973 | Change = ChangeStatus::CHANGED; | |||
3974 | ToBeExploredFrom = std::move(NewToBeExploredFrom); | |||
3975 | } | |||
3976 | ||||
3977 | // If we know everything is live there is no need to query for liveness. | |||
3978 | // Instead, indicating a pessimistic fixpoint will cause the state to be | |||
3979 | // "invalid" and all queries to be answered conservatively without lookups. | |||
3980 | // To be in this state we have to (1) finished the exploration and (3) not | |||
3981 | // discovered any non-trivial dead end and (2) not ruled unreachable code | |||
3982 | // dead. | |||
3983 | if (ToBeExploredFrom.empty() && | |||
3984 | getAnchorScope()->size() == AssumedLiveBlocks.size() && | |||
3985 | llvm::all_of(KnownDeadEnds, [](const Instruction *DeadEndI) { | |||
3986 | return DeadEndI->isTerminator() && DeadEndI->getNumSuccessors() == 0; | |||
3987 | })) | |||
3988 | return indicatePessimisticFixpoint(); | |||
3989 | return Change; | |||
3990 | } | |||
3991 | ||||
3992 | /// Liveness information for a call sites. | |||
3993 | struct AAIsDeadCallSite final : AAIsDeadFunction { | |||
3994 | AAIsDeadCallSite(const IRPosition &IRP, Attributor &A) | |||
3995 | : AAIsDeadFunction(IRP, A) {} | |||
3996 | ||||
3997 | /// See AbstractAttribute::initialize(...). | |||
3998 | void initialize(Attributor &A) override { | |||
3999 | // TODO: Once we have call site specific value information we can provide | |||
4000 | // call site specific liveness information and then it makes | |||
4001 | // sense to specialize attributes for call sites instead of | |||
4002 | // redirecting requests to the callee. | |||
4003 | llvm_unreachable("Abstract attributes for liveness are not "__builtin_unreachable() | |||
4004 | "supported for call sites yet!")__builtin_unreachable(); | |||
4005 | } | |||
4006 | ||||
4007 | /// See AbstractAttribute::updateImpl(...). | |||
4008 | ChangeStatus updateImpl(Attributor &A) override { | |||
4009 | return indicatePessimisticFixpoint(); | |||
4010 | } | |||
4011 | ||||
4012 | /// See AbstractAttribute::trackStatistics() | |||
4013 | void trackStatistics() const override {} | |||
4014 | }; | |||
4015 | ||||
4016 | /// -------------------- Dereferenceable Argument Attribute -------------------- | |||
4017 | ||||
4018 | struct AADereferenceableImpl : AADereferenceable { | |||
4019 | AADereferenceableImpl(const IRPosition &IRP, Attributor &A) | |||
4020 | : AADereferenceable(IRP, A) {} | |||
4021 | using StateType = DerefState; | |||
4022 | ||||
4023 | /// See AbstractAttribute::initialize(...). | |||
4024 | void initialize(Attributor &A) override { | |||
4025 | SmallVector<Attribute, 4> Attrs; | |||
4026 | getAttrs({Attribute::Dereferenceable, Attribute::DereferenceableOrNull}, | |||
4027 | Attrs, /* IgnoreSubsumingPositions */ false, &A); | |||
4028 | for (const Attribute &Attr : Attrs) | |||
4029 | takeKnownDerefBytesMaximum(Attr.getValueAsInt()); | |||
4030 | ||||
4031 | const IRPosition &IRP = this->getIRPosition(); | |||
4032 | NonNullAA = &A.getAAFor<AANonNull>(*this, IRP, DepClassTy::NONE); | |||
4033 | ||||
4034 | bool CanBeNull, CanBeFreed; | |||
4035 | takeKnownDerefBytesMaximum( | |||
4036 | IRP.getAssociatedValue().getPointerDereferenceableBytes( | |||
4037 | A.getDataLayout(), CanBeNull, CanBeFreed)); | |||
4038 | ||||
4039 | bool IsFnInterface = IRP.isFnInterfaceKind(); | |||
4040 | Function *FnScope = IRP.getAnchorScope(); | |||
4041 | if (IsFnInterface && (!FnScope || !A.isFunctionIPOAmendable(*FnScope))) { | |||
4042 | indicatePessimisticFixpoint(); | |||
4043 | return; | |||
4044 | } | |||
4045 | ||||
4046 | if (Instruction *CtxI = getCtxI()) | |||
4047 | followUsesInMBEC(*this, A, getState(), *CtxI); | |||
4048 | } | |||
4049 | ||||
4050 | /// See AbstractAttribute::getState() | |||
4051 | /// { | |||
4052 | StateType &getState() override { return *this; } | |||
4053 | const StateType &getState() const override { return *this; } | |||
4054 | /// } | |||
4055 | ||||
4056 | /// Helper function for collecting accessed bytes in must-be-executed-context | |||
4057 | void addAccessedBytesForUse(Attributor &A, const Use *U, const Instruction *I, | |||
4058 | DerefState &State) { | |||
4059 | const Value *UseV = U->get(); | |||
4060 | if (!UseV->getType()->isPointerTy()) | |||
4061 | return; | |||
4062 | ||||
4063 | Type *PtrTy = UseV->getType(); | |||
4064 | const DataLayout &DL = A.getDataLayout(); | |||
4065 | int64_t Offset; | |||
4066 | if (const Value *Base = getBasePointerOfAccessPointerOperand( | |||
4067 | I, Offset, DL, /*AllowNonInbounds*/ true)) { | |||
4068 | if (Base == &getAssociatedValue() && | |||
4069 | getPointerOperand(I, /* AllowVolatile */ false) == UseV) { | |||
4070 | uint64_t Size = DL.getTypeStoreSize(PtrTy->getPointerElementType()); | |||
4071 | State.addAccessedBytes(Offset, Size); | |||
4072 | } | |||
4073 | } | |||
4074 | } | |||
4075 | ||||
4076 | /// See followUsesInMBEC | |||
4077 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, | |||
4078 | AADereferenceable::StateType &State) { | |||
4079 | bool IsNonNull = false; | |||
4080 | bool TrackUse = false; | |||
4081 | int64_t DerefBytes = getKnownNonNullAndDerefBytesForUse( | |||
4082 | A, *this, getAssociatedValue(), U, I, IsNonNull, TrackUse); | |||
4083 | LLVM_DEBUG(dbgs() << "[AADereferenceable] Deref bytes: " << DerefBytesdo { } while (false) | |||
4084 | << " for instruction " << *I << "\n")do { } while (false); | |||
4085 | ||||
4086 | addAccessedBytesForUse(A, U, I, State); | |||
4087 | State.takeKnownDerefBytesMaximum(DerefBytes); | |||
4088 | return TrackUse; | |||
4089 | } | |||
4090 | ||||
4091 | /// See AbstractAttribute::manifest(...). | |||
4092 | ChangeStatus manifest(Attributor &A) override { | |||
4093 | ChangeStatus Change = AADereferenceable::manifest(A); | |||
4094 | if (isAssumedNonNull() && hasAttr(Attribute::DereferenceableOrNull)) { | |||
4095 | removeAttrs({Attribute::DereferenceableOrNull}); | |||
4096 | return ChangeStatus::CHANGED; | |||
4097 | } | |||
4098 | return Change; | |||
4099 | } | |||
4100 | ||||
4101 | void getDeducedAttributes(LLVMContext &Ctx, | |||
4102 | SmallVectorImpl<Attribute> &Attrs) const override { | |||
4103 | // TODO: Add *_globally support | |||
4104 | if (isAssumedNonNull()) | |||
4105 | Attrs.emplace_back(Attribute::getWithDereferenceableBytes( | |||
4106 | Ctx, getAssumedDereferenceableBytes())); | |||
4107 | else | |||
4108 | Attrs.emplace_back(Attribute::getWithDereferenceableOrNullBytes( | |||
4109 | Ctx, getAssumedDereferenceableBytes())); | |||
4110 | } | |||
4111 | ||||
4112 | /// See AbstractAttribute::getAsStr(). | |||
4113 | const std::string getAsStr() const override { | |||
4114 | if (!getAssumedDereferenceableBytes()) | |||
4115 | return "unknown-dereferenceable"; | |||
4116 | return std::string("dereferenceable") + | |||
4117 | (isAssumedNonNull() ? "" : "_or_null") + | |||
4118 | (isAssumedGlobal() ? "_globally" : "") + "<" + | |||
4119 | std::to_string(getKnownDereferenceableBytes()) + "-" + | |||
4120 | std::to_string(getAssumedDereferenceableBytes()) + ">"; | |||
4121 | } | |||
4122 | }; | |||
4123 | ||||
4124 | /// Dereferenceable attribute for a floating value. | |||
4125 | struct AADereferenceableFloating : AADereferenceableImpl { | |||
4126 | AADereferenceableFloating(const IRPosition &IRP, Attributor &A) | |||
4127 | : AADereferenceableImpl(IRP, A) {} | |||
4128 | ||||
4129 | /// See AbstractAttribute::updateImpl(...). | |||
4130 | ChangeStatus updateImpl(Attributor &A) override { | |||
4131 | const DataLayout &DL = A.getDataLayout(); | |||
4132 | ||||
4133 | auto VisitValueCB = [&](const Value &V, const Instruction *, DerefState &T, | |||
4134 | bool Stripped) -> bool { | |||
4135 | unsigned IdxWidth = | |||
4136 | DL.getIndexSizeInBits(V.getType()->getPointerAddressSpace()); | |||
4137 | APInt Offset(IdxWidth, 0); | |||
4138 | const Value *Base = | |||
4139 | stripAndAccumulateMinimalOffsets(A, *this, &V, DL, Offset, false); | |||
4140 | ||||
4141 | const auto &AA = A.getAAFor<AADereferenceable>( | |||
4142 | *this, IRPosition::value(*Base), DepClassTy::REQUIRED); | |||
4143 | int64_t DerefBytes = 0; | |||
4144 | if (!Stripped && this == &AA) { | |||
4145 | // Use IR information if we did not strip anything. | |||
4146 | // TODO: track globally. | |||
4147 | bool CanBeNull, CanBeFreed; | |||
4148 | DerefBytes = | |||
4149 | Base->getPointerDereferenceableBytes(DL, CanBeNull, CanBeFreed); | |||
4150 | T.GlobalState.indicatePessimisticFixpoint(); | |||
4151 | } else { | |||
4152 | const DerefState &DS = AA.getState(); | |||
4153 | DerefBytes = DS.DerefBytesState.getAssumed(); | |||
4154 | T.GlobalState &= DS.GlobalState; | |||
4155 | } | |||
4156 | ||||
4157 | // For now we do not try to "increase" dereferenceability due to negative | |||
4158 | // indices as we first have to come up with code to deal with loops and | |||
4159 | // for overflows of the dereferenceable bytes. | |||
4160 | int64_t OffsetSExt = Offset.getSExtValue(); | |||
4161 | if (OffsetSExt < 0) | |||
4162 | OffsetSExt = 0; | |||
4163 | ||||
4164 | T.takeAssumedDerefBytesMinimum( | |||
4165 | std::max(int64_t(0), DerefBytes - OffsetSExt)); | |||
4166 | ||||
4167 | if (this == &AA) { | |||
4168 | if (!Stripped) { | |||
4169 | // If nothing was stripped IR information is all we got. | |||
4170 | T.takeKnownDerefBytesMaximum( | |||
4171 | std::max(int64_t(0), DerefBytes - OffsetSExt)); | |||
4172 | T.indicatePessimisticFixpoint(); | |||
4173 | } else if (OffsetSExt > 0) { | |||
4174 | // If something was stripped but there is circular reasoning we look | |||
4175 | // for the offset. If it is positive we basically decrease the | |||
4176 | // dereferenceable bytes in a circluar loop now, which will simply | |||
4177 | // drive them down to the known value in a very slow way which we | |||
4178 | // can accelerate. | |||
4179 | T.indicatePessimisticFixpoint(); | |||
4180 | } | |||
4181 | } | |||
4182 | ||||
4183 | return T.isValidState(); | |||
4184 | }; | |||
4185 | ||||
4186 | DerefState T; | |||
4187 | if (!genericValueTraversal<DerefState>(A, getIRPosition(), *this, T, | |||
4188 | VisitValueCB, getCtxI())) | |||
4189 | return indicatePessimisticFixpoint(); | |||
4190 | ||||
4191 | return clampStateAndIndicateChange(getState(), T); | |||
4192 | } | |||
4193 | ||||
4194 | /// See AbstractAttribute::trackStatistics() | |||
4195 | void trackStatistics() const override { | |||
4196 | STATS_DECLTRACK_FLOATING_ATTR(dereferenceable){ static llvm::Statistic NumIRFloating_dereferenceable = {"attributor" , "NumIRFloating_dereferenceable", ("Number of floating values known to be '" "dereferenceable" "'")};; ++(NumIRFloating_dereferenceable); } | |||
4197 | } | |||
4198 | }; | |||
4199 | ||||
4200 | /// Dereferenceable attribute for a return value. | |||
4201 | struct AADereferenceableReturned final | |||
4202 | : AAReturnedFromReturnedValues<AADereferenceable, AADereferenceableImpl> { | |||
4203 | AADereferenceableReturned(const IRPosition &IRP, Attributor &A) | |||
4204 | : AAReturnedFromReturnedValues<AADereferenceable, AADereferenceableImpl>( | |||
4205 | IRP, A) {} | |||
4206 | ||||
4207 | /// See AbstractAttribute::trackStatistics() | |||
4208 | void trackStatistics() const override { | |||
4209 | STATS_DECLTRACK_FNRET_ATTR(dereferenceable){ static llvm::Statistic NumIRFunctionReturn_dereferenceable = {"attributor", "NumIRFunctionReturn_dereferenceable", ("Number of " "function returns" " marked '" "dereferenceable" "'")};; ++( NumIRFunctionReturn_dereferenceable); } | |||
4210 | } | |||
4211 | }; | |||
4212 | ||||
4213 | /// Dereferenceable attribute for an argument | |||
4214 | struct AADereferenceableArgument final | |||
4215 | : AAArgumentFromCallSiteArguments<AADereferenceable, | |||
4216 | AADereferenceableImpl> { | |||
4217 | using Base = | |||
4218 | AAArgumentFromCallSiteArguments<AADereferenceable, AADereferenceableImpl>; | |||
4219 | AADereferenceableArgument(const IRPosition &IRP, Attributor &A) | |||
4220 | : Base(IRP, A) {} | |||
4221 | ||||
4222 | /// See AbstractAttribute::trackStatistics() | |||
4223 | void trackStatistics() const override { | |||
4224 | STATS_DECLTRACK_ARG_ATTR(dereferenceable){ static llvm::Statistic NumIRArguments_dereferenceable = {"attributor" , "NumIRArguments_dereferenceable", ("Number of " "arguments" " marked '" "dereferenceable" "'")};; ++(NumIRArguments_dereferenceable ); } | |||
4225 | } | |||
4226 | }; | |||
4227 | ||||
4228 | /// Dereferenceable attribute for a call site argument. | |||
4229 | struct AADereferenceableCallSiteArgument final : AADereferenceableFloating { | |||
4230 | AADereferenceableCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
4231 | : AADereferenceableFloating(IRP, A) {} | |||
4232 | ||||
4233 | /// See AbstractAttribute::trackStatistics() | |||
4234 | void trackStatistics() const override { | |||
4235 | STATS_DECLTRACK_CSARG_ATTR(dereferenceable){ static llvm::Statistic NumIRCSArguments_dereferenceable = { "attributor", "NumIRCSArguments_dereferenceable", ("Number of " "call site arguments" " marked '" "dereferenceable" "'")};; ++ (NumIRCSArguments_dereferenceable); } | |||
4236 | } | |||
4237 | }; | |||
4238 | ||||
4239 | /// Dereferenceable attribute deduction for a call site return value. | |||
4240 | struct AADereferenceableCallSiteReturned final | |||
4241 | : AACallSiteReturnedFromReturned<AADereferenceable, AADereferenceableImpl> { | |||
4242 | using Base = | |||
4243 | AACallSiteReturnedFromReturned<AADereferenceable, AADereferenceableImpl>; | |||
4244 | AADereferenceableCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
4245 | : Base(IRP, A) {} | |||
4246 | ||||
4247 | /// See AbstractAttribute::trackStatistics() | |||
4248 | void trackStatistics() const override { | |||
4249 | STATS_DECLTRACK_CS_ATTR(dereferenceable){ static llvm::Statistic NumIRCS_dereferenceable = {"attributor" , "NumIRCS_dereferenceable", ("Number of " "call site" " marked '" "dereferenceable" "'")};; ++(NumIRCS_dereferenceable); }; | |||
4250 | } | |||
4251 | }; | |||
4252 | ||||
4253 | // ------------------------ Align Argument Attribute ------------------------ | |||
4254 | ||||
4255 | static unsigned getKnownAlignForUse(Attributor &A, AAAlign &QueryingAA, | |||
4256 | Value &AssociatedValue, const Use *U, | |||
4257 | const Instruction *I, bool &TrackUse) { | |||
4258 | // We need to follow common pointer manipulation uses to the accesses they | |||
4259 | // feed into. | |||
4260 | if (isa<CastInst>(I)) { | |||
4261 | // Follow all but ptr2int casts. | |||
4262 | TrackUse = !isa<PtrToIntInst>(I); | |||
4263 | return 0; | |||
4264 | } | |||
4265 | if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) { | |||
4266 | if (GEP->hasAllConstantIndices()) | |||
4267 | TrackUse = true; | |||
4268 | return 0; | |||
4269 | } | |||
4270 | ||||
4271 | MaybeAlign MA; | |||
4272 | if (const auto *CB = dyn_cast<CallBase>(I)) { | |||
4273 | if (CB->isBundleOperand(U) || CB->isCallee(U)) | |||
4274 | return 0; | |||
4275 | ||||
4276 | unsigned ArgNo = CB->getArgOperandNo(U); | |||
4277 | IRPosition IRP = IRPosition::callsite_argument(*CB, ArgNo); | |||
4278 | // As long as we only use known information there is no need to track | |||
4279 | // dependences here. | |||
4280 | auto &AlignAA = A.getAAFor<AAAlign>(QueryingAA, IRP, DepClassTy::NONE); | |||
4281 | MA = MaybeAlign(AlignAA.getKnownAlign()); | |||
4282 | } | |||
4283 | ||||
4284 | const DataLayout &DL = A.getDataLayout(); | |||
4285 | const Value *UseV = U->get(); | |||
4286 | if (auto *SI = dyn_cast<StoreInst>(I)) { | |||
4287 | if (SI->getPointerOperand() == UseV) | |||
4288 | MA = SI->getAlign(); | |||
4289 | } else if (auto *LI = dyn_cast<LoadInst>(I)) { | |||
4290 | if (LI->getPointerOperand() == UseV) | |||
4291 | MA = LI->getAlign(); | |||
4292 | } | |||
4293 | ||||
4294 | if (!MA || *MA <= QueryingAA.getKnownAlign()) | |||
4295 | return 0; | |||
4296 | ||||
4297 | unsigned Alignment = MA->value(); | |||
4298 | int64_t Offset; | |||
4299 | ||||
4300 | if (const Value *Base = GetPointerBaseWithConstantOffset(UseV, Offset, DL)) { | |||
4301 | if (Base == &AssociatedValue) { | |||
4302 | // BasePointerAddr + Offset = Alignment * Q for some integer Q. | |||
4303 | // So we can say that the maximum power of two which is a divisor of | |||
4304 | // gcd(Offset, Alignment) is an alignment. | |||
4305 | ||||
4306 | uint32_t gcd = | |||
4307 | greatestCommonDivisor(uint32_t(abs((int32_t)Offset)), Alignment); | |||
4308 | Alignment = llvm::PowerOf2Floor(gcd); | |||
4309 | } | |||
4310 | } | |||
4311 | ||||
4312 | return Alignment; | |||
4313 | } | |||
4314 | ||||
4315 | struct AAAlignImpl : AAAlign { | |||
4316 | AAAlignImpl(const IRPosition &IRP, Attributor &A) : AAAlign(IRP, A) {} | |||
4317 | ||||
4318 | /// See AbstractAttribute::initialize(...). | |||
4319 | void initialize(Attributor &A) override { | |||
4320 | SmallVector<Attribute, 4> Attrs; | |||
4321 | getAttrs({Attribute::Alignment}, Attrs); | |||
4322 | for (const Attribute &Attr : Attrs) | |||
4323 | takeKnownMaximum(Attr.getValueAsInt()); | |||
4324 | ||||
4325 | Value &V = getAssociatedValue(); | |||
4326 | // TODO: This is a HACK to avoid getPointerAlignment to introduce a ptr2int | |||
4327 | // use of the function pointer. This was caused by D73131. We want to | |||
4328 | // avoid this for function pointers especially because we iterate | |||
4329 | // their uses and int2ptr is not handled. It is not a correctness | |||
4330 | // problem though! | |||
4331 | if (!V.getType()->getPointerElementType()->isFunctionTy()) | |||
4332 | takeKnownMaximum(V.getPointerAlignment(A.getDataLayout()).value()); | |||
4333 | ||||
4334 | if (getIRPosition().isFnInterfaceKind() && | |||
4335 | (!getAnchorScope() || | |||
4336 | !A.isFunctionIPOAmendable(*getAssociatedFunction()))) { | |||
4337 | indicatePessimisticFixpoint(); | |||
4338 | return; | |||
4339 | } | |||
4340 | ||||
4341 | if (Instruction *CtxI = getCtxI()) | |||
4342 | followUsesInMBEC(*this, A, getState(), *CtxI); | |||
4343 | } | |||
4344 | ||||
4345 | /// See AbstractAttribute::manifest(...). | |||
4346 | ChangeStatus manifest(Attributor &A) override { | |||
4347 | ChangeStatus LoadStoreChanged = ChangeStatus::UNCHANGED; | |||
4348 | ||||
4349 | // Check for users that allow alignment annotations. | |||
4350 | Value &AssociatedValue = getAssociatedValue(); | |||
4351 | for (const Use &U : AssociatedValue.uses()) { | |||
4352 | if (auto *SI = dyn_cast<StoreInst>(U.getUser())) { | |||
4353 | if (SI->getPointerOperand() == &AssociatedValue) | |||
4354 | if (SI->getAlignment() < getAssumedAlign()) { | |||
4355 | STATS_DECLTRACK(AAAlign, Store,{ static llvm::Statistic NumIRStore_AAAlign = {"attributor", "NumIRStore_AAAlign" , "Number of times alignment added to a store"};; ++(NumIRStore_AAAlign ); } | |||
4356 | "Number of times alignment added to a store"){ static llvm::Statistic NumIRStore_AAAlign = {"attributor", "NumIRStore_AAAlign" , "Number of times alignment added to a store"};; ++(NumIRStore_AAAlign ); }; | |||
4357 | SI->setAlignment(Align(getAssumedAlign())); | |||
4358 | LoadStoreChanged = ChangeStatus::CHANGED; | |||
4359 | } | |||
4360 | } else if (auto *LI = dyn_cast<LoadInst>(U.getUser())) { | |||
4361 | if (LI->getPointerOperand() == &AssociatedValue) | |||
4362 | if (LI->getAlignment() < getAssumedAlign()) { | |||
4363 | LI->setAlignment(Align(getAssumedAlign())); | |||
4364 | STATS_DECLTRACK(AAAlign, Load,{ static llvm::Statistic NumIRLoad_AAAlign = {"attributor", "NumIRLoad_AAAlign" , "Number of times alignment added to a load"};; ++(NumIRLoad_AAAlign ); } | |||
4365 | "Number of times alignment added to a load"){ static llvm::Statistic NumIRLoad_AAAlign = {"attributor", "NumIRLoad_AAAlign" , "Number of times alignment added to a load"};; ++(NumIRLoad_AAAlign ); }; | |||
4366 | LoadStoreChanged = ChangeStatus::CHANGED; | |||
4367 | } | |||
4368 | } | |||
4369 | } | |||
4370 | ||||
4371 | ChangeStatus Changed = AAAlign::manifest(A); | |||
4372 | ||||
4373 | Align InheritAlign = | |||
4374 | getAssociatedValue().getPointerAlignment(A.getDataLayout()); | |||
4375 | if (InheritAlign >= getAssumedAlign()) | |||
4376 | return LoadStoreChanged; | |||
4377 | return Changed | LoadStoreChanged; | |||
4378 | } | |||
4379 | ||||
4380 | // TODO: Provide a helper to determine the implied ABI alignment and check in | |||
4381 | // the existing manifest method and a new one for AAAlignImpl that value | |||
4382 | // to avoid making the alignment explicit if it did not improve. | |||
4383 | ||||
4384 | /// See AbstractAttribute::getDeducedAttributes | |||
4385 | virtual void | |||
4386 | getDeducedAttributes(LLVMContext &Ctx, | |||
4387 | SmallVectorImpl<Attribute> &Attrs) const override { | |||
4388 | if (getAssumedAlign() > 1) | |||
4389 | Attrs.emplace_back( | |||
4390 | Attribute::getWithAlignment(Ctx, Align(getAssumedAlign()))); | |||
4391 | } | |||
4392 | ||||
4393 | /// See followUsesInMBEC | |||
4394 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, | |||
4395 | AAAlign::StateType &State) { | |||
4396 | bool TrackUse = false; | |||
4397 | ||||
4398 | unsigned int KnownAlign = | |||
4399 | getKnownAlignForUse(A, *this, getAssociatedValue(), U, I, TrackUse); | |||
4400 | State.takeKnownMaximum(KnownAlign); | |||
4401 | ||||
4402 | return TrackUse; | |||
4403 | } | |||
4404 | ||||
4405 | /// See AbstractAttribute::getAsStr(). | |||
4406 | const std::string getAsStr() const override { | |||
4407 | return getAssumedAlign() ? ("align<" + std::to_string(getKnownAlign()) + | |||
4408 | "-" + std::to_string(getAssumedAlign()) + ">") | |||
4409 | : "unknown-align"; | |||
4410 | } | |||
4411 | }; | |||
4412 | ||||
4413 | /// Align attribute for a floating value. | |||
4414 | struct AAAlignFloating : AAAlignImpl { | |||
4415 | AAAlignFloating(const IRPosition &IRP, Attributor &A) : AAAlignImpl(IRP, A) {} | |||
4416 | ||||
4417 | /// See AbstractAttribute::updateImpl(...). | |||
4418 | ChangeStatus updateImpl(Attributor &A) override { | |||
4419 | const DataLayout &DL = A.getDataLayout(); | |||
4420 | ||||
4421 | auto VisitValueCB = [&](Value &V, const Instruction *, | |||
4422 | AAAlign::StateType &T, bool Stripped) -> bool { | |||
4423 | const auto &AA = A.getAAFor<AAAlign>(*this, IRPosition::value(V), | |||
4424 | DepClassTy::REQUIRED); | |||
4425 | if (!Stripped && this == &AA) { | |||
4426 | int64_t Offset; | |||
4427 | unsigned Alignment = 1; | |||
4428 | if (const Value *Base = | |||
4429 | GetPointerBaseWithConstantOffset(&V, Offset, DL)) { | |||
4430 | Align PA = Base->getPointerAlignment(DL); | |||
4431 | // BasePointerAddr + Offset = Alignment * Q for some integer Q. | |||
4432 | // So we can say that the maximum power of two which is a divisor of | |||
4433 | // gcd(Offset, Alignment) is an alignment. | |||
4434 | ||||
4435 | uint32_t gcd = greatestCommonDivisor(uint32_t(abs((int32_t)Offset)), | |||
4436 | uint32_t(PA.value())); | |||
4437 | Alignment = llvm::PowerOf2Floor(gcd); | |||
4438 | } else { | |||
4439 | Alignment = V.getPointerAlignment(DL).value(); | |||
4440 | } | |||
4441 | // Use only IR information if we did not strip anything. | |||
4442 | T.takeKnownMaximum(Alignment); | |||
4443 | T.indicatePessimisticFixpoint(); | |||
4444 | } else { | |||
4445 | // Use abstract attribute information. | |||
4446 | const AAAlign::StateType &DS = AA.getState(); | |||
4447 | T ^= DS; | |||
4448 | } | |||
4449 | return T.isValidState(); | |||
4450 | }; | |||
4451 | ||||
4452 | StateType T; | |||
4453 | if (!genericValueTraversal<StateType>(A, getIRPosition(), *this, T, | |||
4454 | VisitValueCB, getCtxI())) | |||
4455 | return indicatePessimisticFixpoint(); | |||
4456 | ||||
4457 | // TODO: If we know we visited all incoming values, thus no are assumed | |||
4458 | // dead, we can take the known information from the state T. | |||
4459 | return clampStateAndIndicateChange(getState(), T); | |||
4460 | } | |||
4461 | ||||
4462 | /// See AbstractAttribute::trackStatistics() | |||
4463 | void trackStatistics() const override { STATS_DECLTRACK_FLOATING_ATTR(align){ static llvm::Statistic NumIRFloating_align = {"attributor", "NumIRFloating_align", ("Number of floating values known to be '" "align" "'")};; ++(NumIRFloating_align); } } | |||
4464 | }; | |||
4465 | ||||
4466 | /// Align attribute for function return value. | |||
4467 | struct AAAlignReturned final | |||
4468 | : AAReturnedFromReturnedValues<AAAlign, AAAlignImpl> { | |||
4469 | using Base = AAReturnedFromReturnedValues<AAAlign, AAAlignImpl>; | |||
4470 | AAAlignReturned(const IRPosition &IRP, Attributor &A) : Base(IRP, A) {} | |||
4471 | ||||
4472 | /// See AbstractAttribute::initialize(...). | |||
4473 | void initialize(Attributor &A) override { | |||
4474 | Base::initialize(A); | |||
4475 | Function *F = getAssociatedFunction(); | |||
4476 | if (!F || F->isDeclaration()) | |||
4477 | indicatePessimisticFixpoint(); | |||
4478 | } | |||
4479 | ||||
4480 | /// See AbstractAttribute::trackStatistics() | |||
4481 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(aligned){ static llvm::Statistic NumIRFunctionReturn_aligned = {"attributor" , "NumIRFunctionReturn_aligned", ("Number of " "function returns" " marked '" "aligned" "'")};; ++(NumIRFunctionReturn_aligned ); } } | |||
4482 | }; | |||
4483 | ||||
4484 | /// Align attribute for function argument. | |||
4485 | struct AAAlignArgument final | |||
4486 | : AAArgumentFromCallSiteArguments<AAAlign, AAAlignImpl> { | |||
4487 | using Base = AAArgumentFromCallSiteArguments<AAAlign, AAAlignImpl>; | |||
4488 | AAAlignArgument(const IRPosition &IRP, Attributor &A) : Base(IRP, A) {} | |||
4489 | ||||
4490 | /// See AbstractAttribute::manifest(...). | |||
4491 | ChangeStatus manifest(Attributor &A) override { | |||
4492 | // If the associated argument is involved in a must-tail call we give up | |||
4493 | // because we would need to keep the argument alignments of caller and | |||
4494 | // callee in-sync. Just does not seem worth the trouble right now. | |||
4495 | if (A.getInfoCache().isInvolvedInMustTailCall(*getAssociatedArgument())) | |||
4496 | return ChangeStatus::UNCHANGED; | |||
4497 | return Base::manifest(A); | |||
4498 | } | |||
4499 | ||||
4500 | /// See AbstractAttribute::trackStatistics() | |||
4501 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(aligned){ static llvm::Statistic NumIRArguments_aligned = {"attributor" , "NumIRArguments_aligned", ("Number of " "arguments" " marked '" "aligned" "'")};; ++(NumIRArguments_aligned); } } | |||
4502 | }; | |||
4503 | ||||
4504 | struct AAAlignCallSiteArgument final : AAAlignFloating { | |||
4505 | AAAlignCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
4506 | : AAAlignFloating(IRP, A) {} | |||
4507 | ||||
4508 | /// See AbstractAttribute::manifest(...). | |||
4509 | ChangeStatus manifest(Attributor &A) override { | |||
4510 | // If the associated argument is involved in a must-tail call we give up | |||
4511 | // because we would need to keep the argument alignments of caller and | |||
4512 | // callee in-sync. Just does not seem worth the trouble right now. | |||
4513 | if (Argument *Arg = getAssociatedArgument()) | |||
4514 | if (A.getInfoCache().isInvolvedInMustTailCall(*Arg)) | |||
4515 | return ChangeStatus::UNCHANGED; | |||
4516 | ChangeStatus Changed = AAAlignImpl::manifest(A); | |||
4517 | Align InheritAlign = | |||
4518 | getAssociatedValue().getPointerAlignment(A.getDataLayout()); | |||
4519 | if (InheritAlign >= getAssumedAlign()) | |||
4520 | Changed = ChangeStatus::UNCHANGED; | |||
4521 | return Changed; | |||
4522 | } | |||
4523 | ||||
4524 | /// See AbstractAttribute::updateImpl(Attributor &A). | |||
4525 | ChangeStatus updateImpl(Attributor &A) override { | |||
4526 | ChangeStatus Changed = AAAlignFloating::updateImpl(A); | |||
4527 | if (Argument *Arg = getAssociatedArgument()) { | |||
4528 | // We only take known information from the argument | |||
4529 | // so we do not need to track a dependence. | |||
4530 | const auto &ArgAlignAA = A.getAAFor<AAAlign>( | |||
4531 | *this, IRPosition::argument(*Arg), DepClassTy::NONE); | |||
4532 | takeKnownMaximum(ArgAlignAA.getKnownAlign()); | |||
4533 | } | |||
4534 | return Changed; | |||
4535 | } | |||
4536 | ||||
4537 | /// See AbstractAttribute::trackStatistics() | |||
4538 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(aligned){ static llvm::Statistic NumIRCSArguments_aligned = {"attributor" , "NumIRCSArguments_aligned", ("Number of " "call site arguments" " marked '" "aligned" "'")};; ++(NumIRCSArguments_aligned); } } | |||
4539 | }; | |||
4540 | ||||
4541 | /// Align attribute deduction for a call site return value. | |||
4542 | struct AAAlignCallSiteReturned final | |||
4543 | : AACallSiteReturnedFromReturned<AAAlign, AAAlignImpl> { | |||
4544 | using Base = AACallSiteReturnedFromReturned<AAAlign, AAAlignImpl>; | |||
4545 | AAAlignCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
4546 | : Base(IRP, A) {} | |||
4547 | ||||
4548 | /// See AbstractAttribute::initialize(...). | |||
4549 | void initialize(Attributor &A) override { | |||
4550 | Base::initialize(A); | |||
4551 | Function *F = getAssociatedFunction(); | |||
4552 | if (!F || F->isDeclaration()) | |||
4553 | indicatePessimisticFixpoint(); | |||
4554 | } | |||
4555 | ||||
4556 | /// See AbstractAttribute::trackStatistics() | |||
4557 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(align){ static llvm::Statistic NumIRCS_align = {"attributor", "NumIRCS_align" , ("Number of " "call site" " marked '" "align" "'")};; ++(NumIRCS_align ); }; } | |||
4558 | }; | |||
4559 | ||||
4560 | /// ------------------ Function No-Return Attribute ---------------------------- | |||
4561 | struct AANoReturnImpl : public AANoReturn { | |||
4562 | AANoReturnImpl(const IRPosition &IRP, Attributor &A) : AANoReturn(IRP, A) {} | |||
4563 | ||||
4564 | /// See AbstractAttribute::initialize(...). | |||
4565 | void initialize(Attributor &A) override { | |||
4566 | AANoReturn::initialize(A); | |||
4567 | Function *F = getAssociatedFunction(); | |||
4568 | if (!F || F->isDeclaration()) | |||
4569 | indicatePessimisticFixpoint(); | |||
4570 | } | |||
4571 | ||||
4572 | /// See AbstractAttribute::getAsStr(). | |||
4573 | const std::string getAsStr() const override { | |||
4574 | return getAssumed() ? "noreturn" : "may-return"; | |||
4575 | } | |||
4576 | ||||
4577 | /// See AbstractAttribute::updateImpl(Attributor &A). | |||
4578 | virtual ChangeStatus updateImpl(Attributor &A) override { | |||
4579 | auto CheckForNoReturn = [](Instruction &) { return false; }; | |||
4580 | bool UsedAssumedInformation = false; | |||
4581 | if (!A.checkForAllInstructions(CheckForNoReturn, *this, | |||
4582 | {(unsigned)Instruction::Ret}, | |||
4583 | UsedAssumedInformation)) | |||
4584 | return indicatePessimisticFixpoint(); | |||
4585 | return ChangeStatus::UNCHANGED; | |||
4586 | } | |||
4587 | }; | |||
4588 | ||||
4589 | struct AANoReturnFunction final : AANoReturnImpl { | |||
4590 | AANoReturnFunction(const IRPosition &IRP, Attributor &A) | |||
4591 | : AANoReturnImpl(IRP, A) {} | |||
4592 | ||||
4593 | /// See AbstractAttribute::trackStatistics() | |||
4594 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(noreturn){ static llvm::Statistic NumIRFunction_noreturn = {"attributor" , "NumIRFunction_noreturn", ("Number of " "functions" " marked '" "noreturn" "'")};; ++(NumIRFunction_noreturn); } } | |||
4595 | }; | |||
4596 | ||||
4597 | /// NoReturn attribute deduction for a call sites. | |||
4598 | struct AANoReturnCallSite final : AANoReturnImpl { | |||
4599 | AANoReturnCallSite(const IRPosition &IRP, Attributor &A) | |||
4600 | : AANoReturnImpl(IRP, A) {} | |||
4601 | ||||
4602 | /// See AbstractAttribute::initialize(...). | |||
4603 | void initialize(Attributor &A) override { | |||
4604 | AANoReturnImpl::initialize(A); | |||
4605 | if (Function *F = getAssociatedFunction()) { | |||
4606 | const IRPosition &FnPos = IRPosition::function(*F); | |||
4607 | auto &FnAA = A.getAAFor<AANoReturn>(*this, FnPos, DepClassTy::REQUIRED); | |||
4608 | if (!FnAA.isAssumedNoReturn()) | |||
4609 | indicatePessimisticFixpoint(); | |||
4610 | } | |||
4611 | } | |||
4612 | ||||
4613 | /// See AbstractAttribute::updateImpl(...). | |||
4614 | ChangeStatus updateImpl(Attributor &A) override { | |||
4615 | // TODO: Once we have call site specific value information we can provide | |||
4616 | // call site specific liveness information and then it makes | |||
4617 | // sense to specialize attributes for call sites arguments instead of | |||
4618 | // redirecting requests to the callee argument. | |||
4619 | Function *F = getAssociatedFunction(); | |||
4620 | const IRPosition &FnPos = IRPosition::function(*F); | |||
4621 | auto &FnAA = A.getAAFor<AANoReturn>(*this, FnPos, DepClassTy::REQUIRED); | |||
4622 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
4623 | } | |||
4624 | ||||
4625 | /// See AbstractAttribute::trackStatistics() | |||
4626 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(noreturn){ static llvm::Statistic NumIRCS_noreturn = {"attributor", "NumIRCS_noreturn" , ("Number of " "call site" " marked '" "noreturn" "'")};; ++ (NumIRCS_noreturn); }; } | |||
4627 | }; | |||
4628 | ||||
4629 | /// ----------------------- Variable Capturing --------------------------------- | |||
4630 | ||||
4631 | /// A class to hold the state of for no-capture attributes. | |||
4632 | struct AANoCaptureImpl : public AANoCapture { | |||
4633 | AANoCaptureImpl(const IRPosition &IRP, Attributor &A) : AANoCapture(IRP, A) {} | |||
4634 | ||||
4635 | /// See AbstractAttribute::initialize(...). | |||
4636 | void initialize(Attributor &A) override { | |||
4637 | if (hasAttr(getAttrKind(), /* IgnoreSubsumingPositions */ true)) { | |||
4638 | indicateOptimisticFixpoint(); | |||
4639 | return; | |||
4640 | } | |||
4641 | Function *AnchorScope = getAnchorScope(); | |||
4642 | if (isFnInterfaceKind() && | |||
4643 | (!AnchorScope || !A.isFunctionIPOAmendable(*AnchorScope))) { | |||
4644 | indicatePessimisticFixpoint(); | |||
4645 | return; | |||
4646 | } | |||
4647 | ||||
4648 | // You cannot "capture" null in the default address space. | |||
4649 | if (isa<ConstantPointerNull>(getAssociatedValue()) && | |||
4650 | getAssociatedValue().getType()->getPointerAddressSpace() == 0) { | |||
4651 | indicateOptimisticFixpoint(); | |||
4652 | return; | |||
4653 | } | |||
4654 | ||||
4655 | const Function *F = | |||
4656 | isArgumentPosition() ? getAssociatedFunction() : AnchorScope; | |||
4657 | ||||
4658 | // Check what state the associated function can actually capture. | |||
4659 | if (F) | |||
4660 | determineFunctionCaptureCapabilities(getIRPosition(), *F, *this); | |||
4661 | else | |||
4662 | indicatePessimisticFixpoint(); | |||
4663 | } | |||
4664 | ||||
4665 | /// See AbstractAttribute::updateImpl(...). | |||
4666 | ChangeStatus updateImpl(Attributor &A) override; | |||
4667 | ||||
4668 | /// see AbstractAttribute::isAssumedNoCaptureMaybeReturned(...). | |||
4669 | virtual void | |||
4670 | getDeducedAttributes(LLVMContext &Ctx, | |||
4671 | SmallVectorImpl<Attribute> &Attrs) const override { | |||
4672 | if (!isAssumedNoCaptureMaybeReturned()) | |||
4673 | return; | |||
4674 | ||||
4675 | if (isArgumentPosition()) { | |||
4676 | if (isAssumedNoCapture()) | |||
4677 | Attrs.emplace_back(Attribute::get(Ctx, Attribute::NoCapture)); | |||
4678 | else if (ManifestInternal) | |||
4679 | Attrs.emplace_back(Attribute::get(Ctx, "no-capture-maybe-returned")); | |||
4680 | } | |||
4681 | } | |||
4682 | ||||
4683 | /// Set the NOT_CAPTURED_IN_MEM and NOT_CAPTURED_IN_RET bits in \p Known | |||
4684 | /// depending on the ability of the function associated with \p IRP to capture | |||
4685 | /// state in memory and through "returning/throwing", respectively. | |||
4686 | static void determineFunctionCaptureCapabilities(const IRPosition &IRP, | |||
4687 | const Function &F, | |||
4688 | BitIntegerState &State) { | |||
4689 | // TODO: Once we have memory behavior attributes we should use them here. | |||
4690 | ||||
4691 | // If we know we cannot communicate or write to memory, we do not care about | |||
4692 | // ptr2int anymore. | |||
4693 | if (F.onlyReadsMemory() && F.doesNotThrow() && | |||
4694 | F.getReturnType()->isVoidTy()) { | |||
4695 | State.addKnownBits(NO_CAPTURE); | |||
4696 | return; | |||
4697 | } | |||
4698 | ||||
4699 | // A function cannot capture state in memory if it only reads memory, it can | |||
4700 | // however return/throw state and the state might be influenced by the | |||
4701 | // pointer value, e.g., loading from a returned pointer might reveal a bit. | |||
4702 | if (F.onlyReadsMemory()) | |||
4703 | State.addKnownBits(NOT_CAPTURED_IN_MEM); | |||
4704 | ||||
4705 | // A function cannot communicate state back if it does not through | |||
4706 | // exceptions and doesn not return values. | |||
4707 | if (F.doesNotThrow() && F.getReturnType()->isVoidTy()) | |||
4708 | State.addKnownBits(NOT_CAPTURED_IN_RET); | |||
4709 | ||||
4710 | // Check existing "returned" attributes. | |||
4711 | int ArgNo = IRP.getCalleeArgNo(); | |||
4712 | if (F.doesNotThrow() && ArgNo >= 0) { | |||
4713 | for (unsigned u = 0, e = F.arg_size(); u < e; ++u) | |||
4714 | if (F.hasParamAttribute(u, Attribute::Returned)) { | |||
4715 | if (u == unsigned(ArgNo)) | |||
4716 | State.removeAssumedBits(NOT_CAPTURED_IN_RET); | |||
4717 | else if (F.onlyReadsMemory()) | |||
4718 | State.addKnownBits(NO_CAPTURE); | |||
4719 | else | |||
4720 | State.addKnownBits(NOT_CAPTURED_IN_RET); | |||
4721 | break; | |||
4722 | } | |||
4723 | } | |||
4724 | } | |||
4725 | ||||
4726 | /// See AbstractState::getAsStr(). | |||
4727 | const std::string getAsStr() const override { | |||
4728 | if (isKnownNoCapture()) | |||
4729 | return "known not-captured"; | |||
4730 | if (isAssumedNoCapture()) | |||
4731 | return "assumed not-captured"; | |||
4732 | if (isKnownNoCaptureMaybeReturned()) | |||
4733 | return "known not-captured-maybe-returned"; | |||
4734 | if (isAssumedNoCaptureMaybeReturned()) | |||
4735 | return "assumed not-captured-maybe-returned"; | |||
4736 | return "assumed-captured"; | |||
4737 | } | |||
4738 | }; | |||
4739 | ||||
4740 | /// Attributor-aware capture tracker. | |||
4741 | struct AACaptureUseTracker final : public CaptureTracker { | |||
4742 | ||||
4743 | /// Create a capture tracker that can lookup in-flight abstract attributes | |||
4744 | /// through the Attributor \p A. | |||
4745 | /// | |||
4746 | /// If a use leads to a potential capture, \p CapturedInMemory is set and the | |||
4747 | /// search is stopped. If a use leads to a return instruction, | |||
4748 | /// \p CommunicatedBack is set to true and \p CapturedInMemory is not changed. | |||
4749 | /// If a use leads to a ptr2int which may capture the value, | |||
4750 | /// \p CapturedInInteger is set. If a use is found that is currently assumed | |||
4751 | /// "no-capture-maybe-returned", the user is added to the \p PotentialCopies | |||
4752 | /// set. All values in \p PotentialCopies are later tracked as well. For every | |||
4753 | /// explored use we decrement \p RemainingUsesToExplore. Once it reaches 0, | |||
4754 | /// the search is stopped with \p CapturedInMemory and \p CapturedInInteger | |||
4755 | /// conservatively set to true. | |||
4756 | AACaptureUseTracker(Attributor &A, AANoCapture &NoCaptureAA, | |||
4757 | const AAIsDead &IsDeadAA, AANoCapture::StateType &State, | |||
4758 | SmallSetVector<Value *, 4> &PotentialCopies, | |||
4759 | unsigned &RemainingUsesToExplore) | |||
4760 | : A(A), NoCaptureAA(NoCaptureAA), IsDeadAA(IsDeadAA), State(State), | |||
4761 | PotentialCopies(PotentialCopies), | |||
4762 | RemainingUsesToExplore(RemainingUsesToExplore) {} | |||
4763 | ||||
4764 | /// Determine if \p V maybe captured. *Also updates the state!* | |||
4765 | bool valueMayBeCaptured(const Value *V) { | |||
4766 | if (V->getType()->isPointerTy()) { | |||
4767 | PointerMayBeCaptured(V, this); | |||
4768 | } else { | |||
4769 | State.indicatePessimisticFixpoint(); | |||
4770 | } | |||
4771 | return State.isAssumed(AANoCapture::NO_CAPTURE_MAYBE_RETURNED); | |||
4772 | } | |||
4773 | ||||
4774 | /// See CaptureTracker::tooManyUses(). | |||
4775 | void tooManyUses() override { | |||
4776 | State.removeAssumedBits(AANoCapture::NO_CAPTURE); | |||
4777 | } | |||
4778 | ||||
4779 | bool isDereferenceableOrNull(Value *O, const DataLayout &DL) override { | |||
4780 | if (CaptureTracker::isDereferenceableOrNull(O, DL)) | |||
4781 | return true; | |||
4782 | const auto &DerefAA = A.getAAFor<AADereferenceable>( | |||
4783 | NoCaptureAA, IRPosition::value(*O), DepClassTy::OPTIONAL); | |||
4784 | return DerefAA.getAssumedDereferenceableBytes(); | |||
4785 | } | |||
4786 | ||||
4787 | /// See CaptureTracker::captured(...). | |||
4788 | bool captured(const Use *U) override { | |||
4789 | Instruction *UInst = cast<Instruction>(U->getUser()); | |||
4790 | LLVM_DEBUG(dbgs() << "Check use: " << *U->get() << " in " << *UInstdo { } while (false) | |||
4791 | << "\n")do { } while (false); | |||
4792 | ||||
4793 | // Because we may reuse the tracker multiple times we keep track of the | |||
4794 | // number of explored uses ourselves as well. | |||
4795 | if (RemainingUsesToExplore-- == 0) { | |||
4796 | LLVM_DEBUG(dbgs() << " - too many uses to explore!\n")do { } while (false); | |||
4797 | return isCapturedIn(/* Memory */ true, /* Integer */ true, | |||
4798 | /* Return */ true); | |||
4799 | } | |||
4800 | ||||
4801 | // Deal with ptr2int by following uses. | |||
4802 | if (isa<PtrToIntInst>(UInst)) { | |||
4803 | LLVM_DEBUG(dbgs() << " - ptr2int assume the worst!\n")do { } while (false); | |||
4804 | return valueMayBeCaptured(UInst); | |||
4805 | } | |||
4806 | ||||
4807 | // For stores we check if we can follow the value through memory or not. | |||
4808 | if (auto *SI = dyn_cast<StoreInst>(UInst)) { | |||
4809 | if (SI->isVolatile()) | |||
4810 | return isCapturedIn(/* Memory */ true, /* Integer */ false, | |||
4811 | /* Return */ false); | |||
4812 | bool UsedAssumedInformation = false; | |||
4813 | if (!AA::getPotentialCopiesOfStoredValue( | |||
4814 | A, *SI, PotentialCopies, NoCaptureAA, UsedAssumedInformation)) | |||
4815 | return isCapturedIn(/* Memory */ true, /* Integer */ false, | |||
4816 | /* Return */ false); | |||
4817 | // Not captured directly, potential copies will be checked. | |||
4818 | return isCapturedIn(/* Memory */ false, /* Integer */ false, | |||
4819 | /* Return */ false); | |||
4820 | } | |||
4821 | ||||
4822 | // Explicitly catch return instructions. | |||
4823 | if (isa<ReturnInst>(UInst)) { | |||
4824 | if (UInst->getFunction() == NoCaptureAA.getAnchorScope()) | |||
4825 | return isCapturedIn(/* Memory */ false, /* Integer */ false, | |||
4826 | /* Return */ true); | |||
4827 | return isCapturedIn(/* Memory */ true, /* Integer */ true, | |||
4828 | /* Return */ true); | |||
4829 | } | |||
4830 | ||||
4831 | // For now we only use special logic for call sites. However, the tracker | |||
4832 | // itself knows about a lot of other non-capturing cases already. | |||
4833 | auto *CB = dyn_cast<CallBase>(UInst); | |||
4834 | if (!CB || !CB->isArgOperand(U)) | |||
4835 | return isCapturedIn(/* Memory */ true, /* Integer */ true, | |||
4836 | /* Return */ true); | |||
4837 | ||||
4838 | unsigned ArgNo = CB->getArgOperandNo(U); | |||
4839 | const IRPosition &CSArgPos = IRPosition::callsite_argument(*CB, ArgNo); | |||
4840 | // If we have a abstract no-capture attribute for the argument we can use | |||
4841 | // it to justify a non-capture attribute here. This allows recursion! | |||
4842 | auto &ArgNoCaptureAA = | |||
4843 | A.getAAFor<AANoCapture>(NoCaptureAA, CSArgPos, DepClassTy::REQUIRED); | |||
4844 | if (ArgNoCaptureAA.isAssumedNoCapture()) | |||
4845 | return isCapturedIn(/* Memory */ false, /* Integer */ false, | |||
4846 | /* Return */ false); | |||
4847 | if (ArgNoCaptureAA.isAssumedNoCaptureMaybeReturned()) { | |||
4848 | addPotentialCopy(*CB); | |||
4849 | return isCapturedIn(/* Memory */ false, /* Integer */ false, | |||
4850 | /* Return */ false); | |||
4851 | } | |||
4852 | ||||
4853 | // Lastly, we could not find a reason no-capture can be assumed so we don't. | |||
4854 | return isCapturedIn(/* Memory */ true, /* Integer */ true, | |||
4855 | /* Return */ true); | |||
4856 | } | |||
4857 | ||||
4858 | /// Register \p CS as potential copy of the value we are checking. | |||
4859 | void addPotentialCopy(CallBase &CB) { PotentialCopies.insert(&CB); } | |||
4860 | ||||
4861 | /// See CaptureTracker::shouldExplore(...). | |||
4862 | bool shouldExplore(const Use *U) override { | |||
4863 | // Check liveness and ignore droppable users. | |||
4864 | bool UsedAssumedInformation = false; | |||
4865 | return !U->getUser()->isDroppable() && | |||
4866 | !A.isAssumedDead(*U, &NoCaptureAA, &IsDeadAA, | |||
4867 | UsedAssumedInformation); | |||
4868 | } | |||
4869 | ||||
4870 | /// Update the state according to \p CapturedInMem, \p CapturedInInt, and | |||
4871 | /// \p CapturedInRet, then return the appropriate value for use in the | |||
4872 | /// CaptureTracker::captured() interface. | |||
4873 | bool isCapturedIn(bool CapturedInMem, bool CapturedInInt, | |||
4874 | bool CapturedInRet) { | |||
4875 | LLVM_DEBUG(dbgs() << " - captures [Mem " << CapturedInMem << "|Int "do { } while (false) | |||
4876 | << CapturedInInt << "|Ret " << CapturedInRet << "]\n")do { } while (false); | |||
4877 | if (CapturedInMem) | |||
4878 | State.removeAssumedBits(AANoCapture::NOT_CAPTURED_IN_MEM); | |||
4879 | if (CapturedInInt) | |||
4880 | State.removeAssumedBits(AANoCapture::NOT_CAPTURED_IN_INT); | |||
4881 | if (CapturedInRet) | |||
4882 | State.removeAssumedBits(AANoCapture::NOT_CAPTURED_IN_RET); | |||
4883 | return !State.isAssumed(AANoCapture::NO_CAPTURE_MAYBE_RETURNED); | |||
4884 | } | |||
4885 | ||||
4886 | private: | |||
4887 | /// The attributor providing in-flight abstract attributes. | |||
4888 | Attributor &A; | |||
4889 | ||||
4890 | /// The abstract attribute currently updated. | |||
4891 | AANoCapture &NoCaptureAA; | |||
4892 | ||||
4893 | /// The abstract liveness state. | |||
4894 | const AAIsDead &IsDeadAA; | |||
4895 | ||||
4896 | /// The state currently updated. | |||
4897 | AANoCapture::StateType &State; | |||
4898 | ||||
4899 | /// Set of potential copies of the tracked value. | |||
4900 | SmallSetVector<Value *, 4> &PotentialCopies; | |||
4901 | ||||
4902 | /// Global counter to limit the number of explored uses. | |||
4903 | unsigned &RemainingUsesToExplore; | |||
4904 | }; | |||
4905 | ||||
4906 | ChangeStatus AANoCaptureImpl::updateImpl(Attributor &A) { | |||
4907 | const IRPosition &IRP = getIRPosition(); | |||
4908 | Value *V = isArgumentPosition() ? IRP.getAssociatedArgument() | |||
4909 | : &IRP.getAssociatedValue(); | |||
4910 | if (!V) | |||
4911 | return indicatePessimisticFixpoint(); | |||
4912 | ||||
4913 | const Function *F = | |||
4914 | isArgumentPosition() ? IRP.getAssociatedFunction() : IRP.getAnchorScope(); | |||
4915 | assert(F && "Expected a function!")((void)0); | |||
4916 | const IRPosition &FnPos = IRPosition::function(*F); | |||
4917 | const auto &IsDeadAA = A.getAAFor<AAIsDead>(*this, FnPos, DepClassTy::NONE); | |||
4918 | ||||
4919 | AANoCapture::StateType T; | |||
4920 | ||||
4921 | // Readonly means we cannot capture through memory. | |||
4922 | const auto &FnMemAA = | |||
4923 | A.getAAFor<AAMemoryBehavior>(*this, FnPos, DepClassTy::NONE); | |||
4924 | if (FnMemAA.isAssumedReadOnly()) { | |||
4925 | T.addKnownBits(NOT_CAPTURED_IN_MEM); | |||
4926 | if (FnMemAA.isKnownReadOnly()) | |||
4927 | addKnownBits(NOT_CAPTURED_IN_MEM); | |||
4928 | else | |||
4929 | A.recordDependence(FnMemAA, *this, DepClassTy::OPTIONAL); | |||
4930 | } | |||
4931 | ||||
4932 | // Make sure all returned values are different than the underlying value. | |||
4933 | // TODO: we could do this in a more sophisticated way inside | |||
4934 | // AAReturnedValues, e.g., track all values that escape through returns | |||
4935 | // directly somehow. | |||
4936 | auto CheckReturnedArgs = [&](const AAReturnedValues &RVAA) { | |||
4937 | bool SeenConstant = false; | |||
4938 | for (auto &It : RVAA.returned_values()) { | |||
4939 | if (isa<Constant>(It.first)) { | |||
4940 | if (SeenConstant) | |||
4941 | return false; | |||
4942 | SeenConstant = true; | |||
4943 | } else if (!isa<Argument>(It.first) || | |||
4944 | It.first == getAssociatedArgument()) | |||
4945 | return false; | |||
4946 | } | |||
4947 | return true; | |||
4948 | }; | |||
4949 | ||||
4950 | const auto &NoUnwindAA = | |||
4951 | A.getAAFor<AANoUnwind>(*this, FnPos, DepClassTy::OPTIONAL); | |||
4952 | if (NoUnwindAA.isAssumedNoUnwind()) { | |||
4953 | bool IsVoidTy = F->getReturnType()->isVoidTy(); | |||
4954 | const AAReturnedValues *RVAA = | |||
4955 | IsVoidTy ? nullptr | |||
4956 | : &A.getAAFor<AAReturnedValues>(*this, FnPos, | |||
4957 | ||||
4958 | DepClassTy::OPTIONAL); | |||
4959 | if (IsVoidTy || CheckReturnedArgs(*RVAA)) { | |||
4960 | T.addKnownBits(NOT_CAPTURED_IN_RET); | |||
4961 | if (T.isKnown(NOT_CAPTURED_IN_MEM)) | |||
4962 | return ChangeStatus::UNCHANGED; | |||
4963 | if (NoUnwindAA.isKnownNoUnwind() && | |||
4964 | (IsVoidTy || RVAA->getState().isAtFixpoint())) { | |||
4965 | addKnownBits(NOT_CAPTURED_IN_RET); | |||
4966 | if (isKnown(NOT_CAPTURED_IN_MEM)) | |||
4967 | return indicateOptimisticFixpoint(); | |||
4968 | } | |||
4969 | } | |||
4970 | } | |||
4971 | ||||
4972 | // Use the CaptureTracker interface and logic with the specialized tracker, | |||
4973 | // defined in AACaptureUseTracker, that can look at in-flight abstract | |||
4974 | // attributes and directly updates the assumed state. | |||
4975 | SmallSetVector<Value *, 4> PotentialCopies; | |||
4976 | unsigned RemainingUsesToExplore = | |||
4977 | getDefaultMaxUsesToExploreForCaptureTracking(); | |||
4978 | AACaptureUseTracker Tracker(A, *this, IsDeadAA, T, PotentialCopies, | |||
4979 | RemainingUsesToExplore); | |||
4980 | ||||
4981 | // Check all potential copies of the associated value until we can assume | |||
4982 | // none will be captured or we have to assume at least one might be. | |||
4983 | unsigned Idx = 0; | |||
4984 | PotentialCopies.insert(V); | |||
4985 | while (T.isAssumed(NO_CAPTURE_MAYBE_RETURNED) && Idx < PotentialCopies.size()) | |||
4986 | Tracker.valueMayBeCaptured(PotentialCopies[Idx++]); | |||
4987 | ||||
4988 | AANoCapture::StateType &S = getState(); | |||
4989 | auto Assumed = S.getAssumed(); | |||
4990 | S.intersectAssumedBits(T.getAssumed()); | |||
4991 | if (!isAssumedNoCaptureMaybeReturned()) | |||
4992 | return indicatePessimisticFixpoint(); | |||
4993 | return Assumed == S.getAssumed() ? ChangeStatus::UNCHANGED | |||
4994 | : ChangeStatus::CHANGED; | |||
4995 | } | |||
4996 | ||||
4997 | /// NoCapture attribute for function arguments. | |||
4998 | struct AANoCaptureArgument final : AANoCaptureImpl { | |||
4999 | AANoCaptureArgument(const IRPosition &IRP, Attributor &A) | |||
5000 | : AANoCaptureImpl(IRP, A) {} | |||
5001 | ||||
5002 | /// See AbstractAttribute::trackStatistics() | |||
5003 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(nocapture){ static llvm::Statistic NumIRArguments_nocapture = {"attributor" , "NumIRArguments_nocapture", ("Number of " "arguments" " marked '" "nocapture" "'")};; ++(NumIRArguments_nocapture); } } | |||
5004 | }; | |||
5005 | ||||
5006 | /// NoCapture attribute for call site arguments. | |||
5007 | struct AANoCaptureCallSiteArgument final : AANoCaptureImpl { | |||
5008 | AANoCaptureCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
5009 | : AANoCaptureImpl(IRP, A) {} | |||
5010 | ||||
5011 | /// See AbstractAttribute::initialize(...). | |||
5012 | void initialize(Attributor &A) override { | |||
5013 | if (Argument *Arg = getAssociatedArgument()) | |||
5014 | if (Arg->hasByValAttr()) | |||
5015 | indicateOptimisticFixpoint(); | |||
5016 | AANoCaptureImpl::initialize(A); | |||
5017 | } | |||
5018 | ||||
5019 | /// See AbstractAttribute::updateImpl(...). | |||
5020 | ChangeStatus updateImpl(Attributor &A) override { | |||
5021 | // TODO: Once we have call site specific value information we can provide | |||
5022 | // call site specific liveness information and then it makes | |||
5023 | // sense to specialize attributes for call sites arguments instead of | |||
5024 | // redirecting requests to the callee argument. | |||
5025 | Argument *Arg = getAssociatedArgument(); | |||
5026 | if (!Arg) | |||
5027 | return indicatePessimisticFixpoint(); | |||
5028 | const IRPosition &ArgPos = IRPosition::argument(*Arg); | |||
5029 | auto &ArgAA = A.getAAFor<AANoCapture>(*this, ArgPos, DepClassTy::REQUIRED); | |||
5030 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); | |||
5031 | } | |||
5032 | ||||
5033 | /// See AbstractAttribute::trackStatistics() | |||
5034 | void trackStatistics() const override{STATS_DECLTRACK_CSARG_ATTR(nocapture){ static llvm::Statistic NumIRCSArguments_nocapture = {"attributor" , "NumIRCSArguments_nocapture", ("Number of " "call site arguments" " marked '" "nocapture" "'")};; ++(NumIRCSArguments_nocapture ); }}; | |||
5035 | }; | |||
5036 | ||||
5037 | /// NoCapture attribute for floating values. | |||
5038 | struct AANoCaptureFloating final : AANoCaptureImpl { | |||
5039 | AANoCaptureFloating(const IRPosition &IRP, Attributor &A) | |||
5040 | : AANoCaptureImpl(IRP, A) {} | |||
5041 | ||||
5042 | /// See AbstractAttribute::trackStatistics() | |||
5043 | void trackStatistics() const override { | |||
5044 | STATS_DECLTRACK_FLOATING_ATTR(nocapture){ static llvm::Statistic NumIRFloating_nocapture = {"attributor" , "NumIRFloating_nocapture", ("Number of floating values known to be '" "nocapture" "'")};; ++(NumIRFloating_nocapture); } | |||
5045 | } | |||
5046 | }; | |||
5047 | ||||
5048 | /// NoCapture attribute for function return value. | |||
5049 | struct AANoCaptureReturned final : AANoCaptureImpl { | |||
5050 | AANoCaptureReturned(const IRPosition &IRP, Attributor &A) | |||
5051 | : AANoCaptureImpl(IRP, A) { | |||
5052 | llvm_unreachable("NoCapture is not applicable to function returns!")__builtin_unreachable(); | |||
5053 | } | |||
5054 | ||||
5055 | /// See AbstractAttribute::initialize(...). | |||
5056 | void initialize(Attributor &A) override { | |||
5057 | llvm_unreachable("NoCapture is not applicable to function returns!")__builtin_unreachable(); | |||
5058 | } | |||
5059 | ||||
5060 | /// See AbstractAttribute::updateImpl(...). | |||
5061 | ChangeStatus updateImpl(Attributor &A) override { | |||
5062 | llvm_unreachable("NoCapture is not applicable to function returns!")__builtin_unreachable(); | |||
5063 | } | |||
5064 | ||||
5065 | /// See AbstractAttribute::trackStatistics() | |||
5066 | void trackStatistics() const override {} | |||
5067 | }; | |||
5068 | ||||
5069 | /// NoCapture attribute deduction for a call site return value. | |||
5070 | struct AANoCaptureCallSiteReturned final : AANoCaptureImpl { | |||
5071 | AANoCaptureCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
5072 | : AANoCaptureImpl(IRP, A) {} | |||
5073 | ||||
5074 | /// See AbstractAttribute::initialize(...). | |||
5075 | void initialize(Attributor &A) override { | |||
5076 | const Function *F = getAnchorScope(); | |||
5077 | // Check what state the associated function can actually capture. | |||
5078 | determineFunctionCaptureCapabilities(getIRPosition(), *F, *this); | |||
5079 | } | |||
5080 | ||||
5081 | /// See AbstractAttribute::trackStatistics() | |||
5082 | void trackStatistics() const override { | |||
5083 | STATS_DECLTRACK_CSRET_ATTR(nocapture){ static llvm::Statistic NumIRCSReturn_nocapture = {"attributor" , "NumIRCSReturn_nocapture", ("Number of " "call site returns" " marked '" "nocapture" "'")};; ++(NumIRCSReturn_nocapture); } | |||
5084 | } | |||
5085 | }; | |||
5086 | ||||
5087 | /// ------------------ Value Simplify Attribute ---------------------------- | |||
5088 | ||||
5089 | bool ValueSimplifyStateType::unionAssumed(Optional<Value *> Other) { | |||
5090 | // FIXME: Add a typecast support. | |||
5091 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( | |||
5092 | SimplifiedAssociatedValue, Other, Ty); | |||
5093 | if (SimplifiedAssociatedValue == Optional<Value *>(nullptr)) | |||
5094 | return false; | |||
5095 | ||||
5096 | LLVM_DEBUG({do { } while (false) | |||
5097 | if (SimplifiedAssociatedValue.hasValue())do { } while (false) | |||
5098 | dbgs() << "[ValueSimplify] is assumed to be "do { } while (false) | |||
5099 | << **SimplifiedAssociatedValue << "\n";do { } while (false) | |||
5100 | elsedo { } while (false) | |||
5101 | dbgs() << "[ValueSimplify] is assumed to be <none>\n";do { } while (false) | |||
5102 | })do { } while (false); | |||
5103 | return true; | |||
5104 | } | |||
5105 | ||||
5106 | struct AAValueSimplifyImpl : AAValueSimplify { | |||
5107 | AAValueSimplifyImpl(const IRPosition &IRP, Attributor &A) | |||
5108 | : AAValueSimplify(IRP, A) {} | |||
5109 | ||||
5110 | /// See AbstractAttribute::initialize(...). | |||
5111 | void initialize(Attributor &A) override { | |||
5112 | if (getAssociatedValue().getType()->isVoidTy()) | |||
5113 | indicatePessimisticFixpoint(); | |||
5114 | if (A.hasSimplificationCallback(getIRPosition())) | |||
5115 | indicatePessimisticFixpoint(); | |||
5116 | } | |||
5117 | ||||
5118 | /// See AbstractAttribute::getAsStr(). | |||
5119 | const std::string getAsStr() const override { | |||
5120 | LLVM_DEBUG({do { } while (false) | |||
5121 | errs() << "SAV: " << SimplifiedAssociatedValue << " ";do { } while (false) | |||
5122 | if (SimplifiedAssociatedValue && *SimplifiedAssociatedValue)do { } while (false) | |||
5123 | errs() << "SAV: " << **SimplifiedAssociatedValue << " ";do { } while (false) | |||
5124 | })do { } while (false); | |||
5125 | return isValidState() ? (isAtFixpoint() ? "simplified" : "maybe-simple") | |||
5126 | : "not-simple"; | |||
5127 | } | |||
5128 | ||||
5129 | /// See AbstractAttribute::trackStatistics() | |||
5130 | void trackStatistics() const override {} | |||
5131 | ||||
5132 | /// See AAValueSimplify::getAssumedSimplifiedValue() | |||
5133 | Optional<Value *> getAssumedSimplifiedValue(Attributor &A) const override { | |||
5134 | return SimplifiedAssociatedValue; | |||
5135 | } | |||
5136 | ||||
5137 | /// Return a value we can use as replacement for the associated one, or | |||
5138 | /// nullptr if we don't have one that makes sense. | |||
5139 | Value *getReplacementValue(Attributor &A) const { | |||
5140 | Value *NewV; | |||
5141 | NewV = SimplifiedAssociatedValue.hasValue() | |||
5142 | ? SimplifiedAssociatedValue.getValue() | |||
5143 | : UndefValue::get(getAssociatedType()); | |||
5144 | if (!NewV) | |||
5145 | return nullptr; | |||
5146 | NewV = AA::getWithType(*NewV, *getAssociatedType()); | |||
5147 | if (!NewV || NewV == &getAssociatedValue()) | |||
5148 | return nullptr; | |||
5149 | const Instruction *CtxI = getCtxI(); | |||
5150 | if (CtxI && !AA::isValidAtPosition(*NewV, *CtxI, A.getInfoCache())) | |||
5151 | return nullptr; | |||
5152 | if (!CtxI && !AA::isValidInScope(*NewV, getAnchorScope())) | |||
5153 | return nullptr; | |||
5154 | return NewV; | |||
5155 | } | |||
5156 | ||||
5157 | /// Helper function for querying AAValueSimplify and updating candicate. | |||
5158 | /// \param IRP The value position we are trying to unify with SimplifiedValue | |||
5159 | bool checkAndUpdate(Attributor &A, const AbstractAttribute &QueryingAA, | |||
5160 | const IRPosition &IRP, bool Simplify = true) { | |||
5161 | bool UsedAssumedInformation = false; | |||
5162 | Optional<Value *> QueryingValueSimplified = &IRP.getAssociatedValue(); | |||
5163 | if (Simplify) | |||
5164 | QueryingValueSimplified = | |||
5165 | A.getAssumedSimplified(IRP, QueryingAA, UsedAssumedInformation); | |||
5166 | return unionAssumed(QueryingValueSimplified); | |||
5167 | } | |||
5168 | ||||
5169 | /// Returns a candidate is found or not | |||
5170 | template <typename AAType> bool askSimplifiedValueFor(Attributor &A) { | |||
5171 | if (!getAssociatedValue().getType()->isIntegerTy()) | |||
5172 | return false; | |||
5173 | ||||
5174 | // This will also pass the call base context. | |||
5175 | const auto &AA = | |||
5176 | A.getAAFor<AAType>(*this, getIRPosition(), DepClassTy::NONE); | |||
5177 | ||||
5178 | Optional<ConstantInt *> COpt = AA.getAssumedConstantInt(A); | |||
5179 | ||||
5180 | if (!COpt.hasValue()) { | |||
5181 | SimplifiedAssociatedValue = llvm::None; | |||
5182 | A.recordDependence(AA, *this, DepClassTy::OPTIONAL); | |||
5183 | return true; | |||
5184 | } | |||
5185 | if (auto *C = COpt.getValue()) { | |||
5186 | SimplifiedAssociatedValue = C; | |||
5187 | A.recordDependence(AA, *this, DepClassTy::OPTIONAL); | |||
5188 | return true; | |||
5189 | } | |||
5190 | return false; | |||
5191 | } | |||
5192 | ||||
5193 | bool askSimplifiedValueForOtherAAs(Attributor &A) { | |||
5194 | if (askSimplifiedValueFor<AAValueConstantRange>(A)) | |||
5195 | return true; | |||
5196 | if (askSimplifiedValueFor<AAPotentialValues>(A)) | |||
5197 | return true; | |||
5198 | return false; | |||
5199 | } | |||
5200 | ||||
5201 | /// See AbstractAttribute::manifest(...). | |||
5202 | ChangeStatus manifest(Attributor &A) override { | |||
5203 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
5204 | if (getAssociatedValue().user_empty()) | |||
5205 | return Changed; | |||
5206 | ||||
5207 | if (auto *NewV = getReplacementValue(A)) { | |||
5208 | LLVM_DEBUG(dbgs() << "[ValueSimplify] " << getAssociatedValue() << " -> "do { } while (false) | |||
5209 | << *NewV << " :: " << *this << "\n")do { } while (false); | |||
5210 | if (A.changeValueAfterManifest(getAssociatedValue(), *NewV)) | |||
5211 | Changed = ChangeStatus::CHANGED; | |||
5212 | } | |||
5213 | ||||
5214 | return Changed | AAValueSimplify::manifest(A); | |||
5215 | } | |||
5216 | ||||
5217 | /// See AbstractState::indicatePessimisticFixpoint(...). | |||
5218 | ChangeStatus indicatePessimisticFixpoint() override { | |||
5219 | SimplifiedAssociatedValue = &getAssociatedValue(); | |||
5220 | return AAValueSimplify::indicatePessimisticFixpoint(); | |||
5221 | } | |||
5222 | ||||
5223 | static bool handleLoad(Attributor &A, const AbstractAttribute &AA, | |||
5224 | LoadInst &L, function_ref<bool(Value &)> Union) { | |||
5225 | auto UnionWrapper = [&](Value &V, Value &Obj) { | |||
5226 | if (isa<AllocaInst>(Obj)) | |||
5227 | return Union(V); | |||
5228 | if (!AA::isDynamicallyUnique(A, AA, V)) | |||
5229 | return false; | |||
5230 | if (!AA::isValidAtPosition(V, L, A.getInfoCache())) | |||
5231 | return false; | |||
5232 | return Union(V); | |||
5233 | }; | |||
5234 | ||||
5235 | Value &Ptr = *L.getPointerOperand(); | |||
5236 | SmallVector<Value *, 8> Objects; | |||
5237 | if (!AA::getAssumedUnderlyingObjects(A, Ptr, Objects, AA, &L)) | |||
5238 | return false; | |||
5239 | ||||
5240 | for (Value *Obj : Objects) { | |||
5241 | LLVM_DEBUG(dbgs() << "Visit underlying object " << *Obj << "\n")do { } while (false); | |||
5242 | if (isa<UndefValue>(Obj)) | |||
5243 | continue; | |||
5244 | if (isa<ConstantPointerNull>(Obj)) { | |||
5245 | // A null pointer access can be undefined but any offset from null may | |||
5246 | // be OK. We do not try to optimize the latter. | |||
5247 | bool UsedAssumedInformation = false; | |||
5248 | if (!NullPointerIsDefined(L.getFunction(), | |||
5249 | Ptr.getType()->getPointerAddressSpace()) && | |||
5250 | A.getAssumedSimplified(Ptr, AA, UsedAssumedInformation) == Obj) | |||
5251 | continue; | |||
5252 | return false; | |||
5253 | } | |||
5254 | if (!isa<AllocaInst>(Obj) && !isa<GlobalVariable>(Obj)) | |||
5255 | return false; | |||
5256 | Constant *InitialVal = AA::getInitialValueForObj(*Obj, *L.getType()); | |||
5257 | if (!InitialVal || !Union(*InitialVal)) | |||
5258 | return false; | |||
5259 | ||||
5260 | LLVM_DEBUG(dbgs() << "Underlying object amenable to load-store "do { } while (false) | |||
5261 | "propagation, checking accesses next.\n")do { } while (false); | |||
5262 | ||||
5263 | auto CheckAccess = [&](const AAPointerInfo::Access &Acc, bool IsExact) { | |||
5264 | LLVM_DEBUG(dbgs() << " - visit access " << Acc << "\n")do { } while (false); | |||
5265 | if (!Acc.isWrite()) | |||
5266 | return true; | |||
5267 | if (Acc.isWrittenValueYetUndetermined()) | |||
5268 | return true; | |||
5269 | Value *Content = Acc.getWrittenValue(); | |||
5270 | if (!Content) | |||
5271 | return false; | |||
5272 | Value *CastedContent = | |||
5273 | AA::getWithType(*Content, *AA.getAssociatedType()); | |||
5274 | if (!CastedContent) | |||
5275 | return false; | |||
5276 | if (IsExact) | |||
5277 | return UnionWrapper(*CastedContent, *Obj); | |||
5278 | if (auto *C = dyn_cast<Constant>(CastedContent)) | |||
5279 | if (C->isNullValue() || C->isAllOnesValue() || isa<UndefValue>(C)) | |||
5280 | return UnionWrapper(*CastedContent, *Obj); | |||
5281 | return false; | |||
5282 | }; | |||
5283 | ||||
5284 | auto &PI = A.getAAFor<AAPointerInfo>(AA, IRPosition::value(*Obj), | |||
5285 | DepClassTy::REQUIRED); | |||
5286 | if (!PI.forallInterferingAccesses(L, CheckAccess)) | |||
5287 | return false; | |||
5288 | } | |||
5289 | return true; | |||
5290 | } | |||
5291 | }; | |||
5292 | ||||
5293 | struct AAValueSimplifyArgument final : AAValueSimplifyImpl { | |||
5294 | AAValueSimplifyArgument(const IRPosition &IRP, Attributor &A) | |||
5295 | : AAValueSimplifyImpl(IRP, A) {} | |||
5296 | ||||
5297 | void initialize(Attributor &A) override { | |||
5298 | AAValueSimplifyImpl::initialize(A); | |||
5299 | if (!getAnchorScope() || getAnchorScope()->isDeclaration()) | |||
5300 | indicatePessimisticFixpoint(); | |||
5301 | if (hasAttr({Attribute::InAlloca, Attribute::Preallocated, | |||
5302 | Attribute::StructRet, Attribute::Nest, Attribute::ByVal}, | |||
5303 | /* IgnoreSubsumingPositions */ true)) | |||
5304 | indicatePessimisticFixpoint(); | |||
5305 | ||||
5306 | // FIXME: This is a hack to prevent us from propagating function poiner in | |||
5307 | // the new pass manager CGSCC pass as it creates call edges the | |||
5308 | // CallGraphUpdater cannot handle yet. | |||
5309 | Value &V = getAssociatedValue(); | |||
5310 | if (V.getType()->isPointerTy() && | |||
5311 | V.getType()->getPointerElementType()->isFunctionTy() && | |||
5312 | !A.isModulePass()) | |||
5313 | indicatePessimisticFixpoint(); | |||
5314 | } | |||
5315 | ||||
5316 | /// See AbstractAttribute::updateImpl(...). | |||
5317 | ChangeStatus updateImpl(Attributor &A) override { | |||
5318 | // Byval is only replacable if it is readonly otherwise we would write into | |||
5319 | // the replaced value and not the copy that byval creates implicitly. | |||
5320 | Argument *Arg = getAssociatedArgument(); | |||
5321 | if (Arg->hasByValAttr()) { | |||
5322 | // TODO: We probably need to verify synchronization is not an issue, e.g., | |||
5323 | // there is no race by not copying a constant byval. | |||
5324 | const auto &MemAA = A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), | |||
5325 | DepClassTy::REQUIRED); | |||
5326 | if (!MemAA.isAssumedReadOnly()) | |||
5327 | return indicatePessimisticFixpoint(); | |||
5328 | } | |||
5329 | ||||
5330 | auto Before = SimplifiedAssociatedValue; | |||
5331 | ||||
5332 | auto PredForCallSite = [&](AbstractCallSite ACS) { | |||
5333 | const IRPosition &ACSArgPos = | |||
5334 | IRPosition::callsite_argument(ACS, getCallSiteArgNo()); | |||
5335 | // Check if a coresponding argument was found or if it is on not | |||
5336 | // associated (which can happen for callback calls). | |||
5337 | if (ACSArgPos.getPositionKind() == IRPosition::IRP_INVALID) | |||
5338 | return false; | |||
5339 | ||||
5340 | // Simplify the argument operand explicitly and check if the result is | |||
5341 | // valid in the current scope. This avoids refering to simplified values | |||
5342 | // in other functions, e.g., we don't want to say a an argument in a | |||
5343 | // static function is actually an argument in a different function. | |||
5344 | bool UsedAssumedInformation = false; | |||
5345 | Optional<Constant *> SimpleArgOp = | |||
5346 | A.getAssumedConstant(ACSArgPos, *this, UsedAssumedInformation); | |||
5347 | if (!SimpleArgOp.hasValue()) | |||
5348 | return true; | |||
5349 | if (!SimpleArgOp.getValue()) | |||
5350 | return false; | |||
5351 | if (!AA::isDynamicallyUnique(A, *this, **SimpleArgOp)) | |||
5352 | return false; | |||
5353 | return unionAssumed(*SimpleArgOp); | |||
5354 | }; | |||
5355 | ||||
5356 | // Generate a answer specific to a call site context. | |||
5357 | bool Success; | |||
5358 | bool AllCallSitesKnown; | |||
5359 | if (hasCallBaseContext() && | |||
5360 | getCallBaseContext()->getCalledFunction() == Arg->getParent()) | |||
5361 | Success = PredForCallSite( | |||
5362 | AbstractCallSite(&getCallBaseContext()->getCalledOperandUse())); | |||
5363 | else | |||
5364 | Success = A.checkForAllCallSites(PredForCallSite, *this, true, | |||
5365 | AllCallSitesKnown); | |||
5366 | ||||
5367 | if (!Success) | |||
5368 | if (!askSimplifiedValueForOtherAAs(A)) | |||
5369 | return indicatePessimisticFixpoint(); | |||
5370 | ||||
5371 | // If a candicate was found in this update, return CHANGED. | |||
5372 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED | |||
5373 | : ChangeStatus ::CHANGED; | |||
5374 | } | |||
5375 | ||||
5376 | /// See AbstractAttribute::trackStatistics() | |||
5377 | void trackStatistics() const override { | |||
5378 | STATS_DECLTRACK_ARG_ATTR(value_simplify){ static llvm::Statistic NumIRArguments_value_simplify = {"attributor" , "NumIRArguments_value_simplify", ("Number of " "arguments" " marked '" "value_simplify" "'")};; ++(NumIRArguments_value_simplify); } | |||
5379 | } | |||
5380 | }; | |||
5381 | ||||
5382 | struct AAValueSimplifyReturned : AAValueSimplifyImpl { | |||
5383 | AAValueSimplifyReturned(const IRPosition &IRP, Attributor &A) | |||
5384 | : AAValueSimplifyImpl(IRP, A) {} | |||
5385 | ||||
5386 | /// See AAValueSimplify::getAssumedSimplifiedValue() | |||
5387 | Optional<Value *> getAssumedSimplifiedValue(Attributor &A) const override { | |||
5388 | if (!isValidState()) | |||
5389 | return nullptr; | |||
5390 | return SimplifiedAssociatedValue; | |||
5391 | } | |||
5392 | ||||
5393 | /// See AbstractAttribute::updateImpl(...). | |||
5394 | ChangeStatus updateImpl(Attributor &A) override { | |||
5395 | auto Before = SimplifiedAssociatedValue; | |||
5396 | ||||
5397 | auto PredForReturned = [&](Value &V) { | |||
5398 | return checkAndUpdate(A, *this, | |||
5399 | IRPosition::value(V, getCallBaseContext())); | |||
5400 | }; | |||
5401 | ||||
5402 | if (!A.checkForAllReturnedValues(PredForReturned, *this)) | |||
5403 | if (!askSimplifiedValueForOtherAAs(A)) | |||
5404 | return indicatePessimisticFixpoint(); | |||
5405 | ||||
5406 | // If a candicate was found in this update, return CHANGED. | |||
5407 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED | |||
5408 | : ChangeStatus ::CHANGED; | |||
5409 | } | |||
5410 | ||||
5411 | ChangeStatus manifest(Attributor &A) override { | |||
5412 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
5413 | ||||
5414 | if (auto *NewV = getReplacementValue(A)) { | |||
5415 | auto PredForReturned = | |||
5416 | [&](Value &, const SmallSetVector<ReturnInst *, 4> &RetInsts) { | |||
5417 | for (ReturnInst *RI : RetInsts) { | |||
5418 | Value *ReturnedVal = RI->getReturnValue(); | |||
5419 | if (ReturnedVal == NewV || isa<UndefValue>(ReturnedVal)) | |||
5420 | return true; | |||
5421 | assert(RI->getFunction() == getAnchorScope() &&((void)0) | |||
5422 | "ReturnInst in wrong function!")((void)0); | |||
5423 | LLVM_DEBUG(dbgs()do { } while (false) | |||
5424 | << "[ValueSimplify] " << *ReturnedVal << " -> "do { } while (false) | |||
5425 | << *NewV << " in " << *RI << " :: " << *this << "\n")do { } while (false); | |||
5426 | if (A.changeUseAfterManifest(RI->getOperandUse(0), *NewV)) | |||
5427 | Changed = ChangeStatus::CHANGED; | |||
5428 | } | |||
5429 | return true; | |||
5430 | }; | |||
5431 | A.checkForAllReturnedValuesAndReturnInsts(PredForReturned, *this); | |||
5432 | } | |||
5433 | ||||
5434 | return Changed | AAValueSimplify::manifest(A); | |||
5435 | } | |||
5436 | ||||
5437 | /// See AbstractAttribute::trackStatistics() | |||
5438 | void trackStatistics() const override { | |||
5439 | STATS_DECLTRACK_FNRET_ATTR(value_simplify){ static llvm::Statistic NumIRFunctionReturn_value_simplify = {"attributor", "NumIRFunctionReturn_value_simplify", ("Number of " "function returns" " marked '" "value_simplify" "'")};; ++(NumIRFunctionReturn_value_simplify ); } | |||
5440 | } | |||
5441 | }; | |||
5442 | ||||
5443 | struct AAValueSimplifyFloating : AAValueSimplifyImpl { | |||
5444 | AAValueSimplifyFloating(const IRPosition &IRP, Attributor &A) | |||
5445 | : AAValueSimplifyImpl(IRP, A) {} | |||
5446 | ||||
5447 | /// See AbstractAttribute::initialize(...). | |||
5448 | void initialize(Attributor &A) override { | |||
5449 | AAValueSimplifyImpl::initialize(A); | |||
5450 | Value &V = getAnchorValue(); | |||
5451 | ||||
5452 | // TODO: add other stuffs | |||
5453 | if (isa<Constant>(V)) | |||
5454 | indicatePessimisticFixpoint(); | |||
5455 | } | |||
5456 | ||||
5457 | /// Check if \p Cmp is a comparison we can simplify. | |||
5458 | /// | |||
5459 | /// We handle multiple cases, one in which at least one operand is an | |||
5460 | /// (assumed) nullptr. If so, try to simplify it using AANonNull on the other | |||
5461 | /// operand. Return true if successful, in that case SimplifiedAssociatedValue | |||
5462 | /// will be updated. | |||
5463 | bool handleCmp(Attributor &A, CmpInst &Cmp) { | |||
5464 | auto Union = [&](Value &V) { | |||
5465 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( | |||
5466 | SimplifiedAssociatedValue, &V, V.getType()); | |||
5467 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); | |||
5468 | }; | |||
5469 | ||||
5470 | Value *LHS = Cmp.getOperand(0); | |||
5471 | Value *RHS = Cmp.getOperand(1); | |||
5472 | ||||
5473 | // Simplify the operands first. | |||
5474 | bool UsedAssumedInformation = false; | |||
5475 | const auto &SimplifiedLHS = | |||
5476 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), | |||
5477 | *this, UsedAssumedInformation); | |||
5478 | if (!SimplifiedLHS.hasValue()) | |||
5479 | return true; | |||
5480 | if (!SimplifiedLHS.getValue()) | |||
5481 | return false; | |||
5482 | LHS = *SimplifiedLHS; | |||
5483 | ||||
5484 | const auto &SimplifiedRHS = | |||
5485 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), | |||
5486 | *this, UsedAssumedInformation); | |||
5487 | if (!SimplifiedRHS.hasValue()) | |||
5488 | return true; | |||
5489 | if (!SimplifiedRHS.getValue()) | |||
5490 | return false; | |||
5491 | RHS = *SimplifiedRHS; | |||
5492 | ||||
5493 | LLVMContext &Ctx = Cmp.getContext(); | |||
5494 | // Handle the trivial case first in which we don't even need to think about | |||
5495 | // null or non-null. | |||
5496 | if (LHS == RHS && (Cmp.isTrueWhenEqual() || Cmp.isFalseWhenEqual())) { | |||
5497 | Constant *NewVal = | |||
5498 | ConstantInt::get(Type::getInt1Ty(Ctx), Cmp.isTrueWhenEqual()); | |||
5499 | if (!Union(*NewVal)) | |||
5500 | return false; | |||
5501 | if (!UsedAssumedInformation) | |||
5502 | indicateOptimisticFixpoint(); | |||
5503 | return true; | |||
5504 | } | |||
5505 | ||||
5506 | // From now on we only handle equalities (==, !=). | |||
5507 | ICmpInst *ICmp = dyn_cast<ICmpInst>(&Cmp); | |||
5508 | if (!ICmp || !ICmp->isEquality()) | |||
5509 | return false; | |||
5510 | ||||
5511 | bool LHSIsNull = isa<ConstantPointerNull>(LHS); | |||
5512 | bool RHSIsNull = isa<ConstantPointerNull>(RHS); | |||
5513 | if (!LHSIsNull && !RHSIsNull) | |||
5514 | return false; | |||
5515 | ||||
5516 | // Left is the nullptr ==/!= non-nullptr case. We'll use AANonNull on the | |||
5517 | // non-nullptr operand and if we assume it's non-null we can conclude the | |||
5518 | // result of the comparison. | |||
5519 | assert((LHSIsNull || RHSIsNull) &&((void)0) | |||
5520 | "Expected nullptr versus non-nullptr comparison at this point")((void)0); | |||
5521 | ||||
5522 | // The index is the operand that we assume is not null. | |||
5523 | unsigned PtrIdx = LHSIsNull; | |||
5524 | auto &PtrNonNullAA = A.getAAFor<AANonNull>( | |||
5525 | *this, IRPosition::value(*ICmp->getOperand(PtrIdx)), | |||
5526 | DepClassTy::REQUIRED); | |||
5527 | if (!PtrNonNullAA.isAssumedNonNull()) | |||
5528 | return false; | |||
5529 | UsedAssumedInformation |= !PtrNonNullAA.isKnownNonNull(); | |||
5530 | ||||
5531 | // The new value depends on the predicate, true for != and false for ==. | |||
5532 | Constant *NewVal = ConstantInt::get( | |||
5533 | Type::getInt1Ty(Ctx), ICmp->getPredicate() == CmpInst::ICMP_NE); | |||
5534 | if (!Union(*NewVal)) | |||
5535 | return false; | |||
5536 | ||||
5537 | if (!UsedAssumedInformation) | |||
5538 | indicateOptimisticFixpoint(); | |||
5539 | ||||
5540 | return true; | |||
5541 | } | |||
5542 | ||||
5543 | bool updateWithLoad(Attributor &A, LoadInst &L) { | |||
5544 | auto Union = [&](Value &V) { | |||
5545 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( | |||
5546 | SimplifiedAssociatedValue, &V, L.getType()); | |||
5547 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); | |||
5548 | }; | |||
5549 | return handleLoad(A, *this, L, Union); | |||
5550 | } | |||
5551 | ||||
5552 | /// Use the generic, non-optimistic InstSimplfy functionality if we managed to | |||
5553 | /// simplify any operand of the instruction \p I. Return true if successful, | |||
5554 | /// in that case SimplifiedAssociatedValue will be updated. | |||
5555 | bool handleGenericInst(Attributor &A, Instruction &I) { | |||
5556 | bool SomeSimplified = false; | |||
5557 | bool UsedAssumedInformation = false; | |||
5558 | ||||
5559 | SmallVector<Value *, 8> NewOps(I.getNumOperands()); | |||
5560 | int Idx = 0; | |||
5561 | for (Value *Op : I.operands()) { | |||
5562 | const auto &SimplifiedOp = | |||
5563 | A.getAssumedSimplified(IRPosition::value(*Op, getCallBaseContext()), | |||
5564 | *this, UsedAssumedInformation); | |||
5565 | // If we are not sure about any operand we are not sure about the entire | |||
5566 | // instruction, we'll wait. | |||
5567 | if (!SimplifiedOp.hasValue()) | |||
5568 | return true; | |||
5569 | ||||
5570 | if (SimplifiedOp.getValue()) | |||
5571 | NewOps[Idx] = SimplifiedOp.getValue(); | |||
5572 | else | |||
5573 | NewOps[Idx] = Op; | |||
5574 | ||||
5575 | SomeSimplified |= (NewOps[Idx] != Op); | |||
5576 | ++Idx; | |||
5577 | } | |||
5578 | ||||
5579 | // We won't bother with the InstSimplify interface if we didn't simplify any | |||
5580 | // operand ourselves. | |||
5581 | if (!SomeSimplified) | |||
5582 | return false; | |||
5583 | ||||
5584 | InformationCache &InfoCache = A.getInfoCache(); | |||
5585 | Function *F = I.getFunction(); | |||
5586 | const auto *DT = | |||
5587 | InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>(*F); | |||
5588 | const auto *TLI = A.getInfoCache().getTargetLibraryInfoForFunction(*F); | |||
5589 | auto *AC = InfoCache.getAnalysisResultForFunction<AssumptionAnalysis>(*F); | |||
5590 | OptimizationRemarkEmitter *ORE = nullptr; | |||
5591 | ||||
5592 | const DataLayout &DL = I.getModule()->getDataLayout(); | |||
5593 | SimplifyQuery Q(DL, TLI, DT, AC, &I); | |||
5594 | if (Value *SimplifiedI = | |||
5595 | SimplifyInstructionWithOperands(&I, NewOps, Q, ORE)) { | |||
5596 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( | |||
5597 | SimplifiedAssociatedValue, SimplifiedI, I.getType()); | |||
5598 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); | |||
5599 | } | |||
5600 | return false; | |||
5601 | } | |||
5602 | ||||
5603 | /// See AbstractAttribute::updateImpl(...). | |||
5604 | ChangeStatus updateImpl(Attributor &A) override { | |||
5605 | auto Before = SimplifiedAssociatedValue; | |||
5606 | ||||
5607 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, bool &, | |||
5608 | bool Stripped) -> bool { | |||
5609 | auto &AA = A.getAAFor<AAValueSimplify>( | |||
5610 | *this, IRPosition::value(V, getCallBaseContext()), | |||
5611 | DepClassTy::REQUIRED); | |||
5612 | if (!Stripped && this == &AA) { | |||
5613 | ||||
5614 | if (auto *I = dyn_cast<Instruction>(&V)) { | |||
5615 | if (auto *LI = dyn_cast<LoadInst>(&V)) | |||
5616 | if (updateWithLoad(A, *LI)) | |||
5617 | return true; | |||
5618 | if (auto *Cmp = dyn_cast<CmpInst>(&V)) | |||
5619 | if (handleCmp(A, *Cmp)) | |||
5620 | return true; | |||
5621 | if (handleGenericInst(A, *I)) | |||
5622 | return true; | |||
5623 | } | |||
5624 | // TODO: Look the instruction and check recursively. | |||
5625 | ||||
5626 | LLVM_DEBUG(dbgs() << "[ValueSimplify] Can't be stripped more : " << Vdo { } while (false) | |||
5627 | << "\n")do { } while (false); | |||
5628 | return false; | |||
5629 | } | |||
5630 | return checkAndUpdate(A, *this, | |||
5631 | IRPosition::value(V, getCallBaseContext())); | |||
5632 | }; | |||
5633 | ||||
5634 | bool Dummy = false; | |||
5635 | if (!genericValueTraversal<bool>(A, getIRPosition(), *this, Dummy, | |||
5636 | VisitValueCB, getCtxI(), | |||
5637 | /* UseValueSimplify */ false)) | |||
5638 | if (!askSimplifiedValueForOtherAAs(A)) | |||
5639 | return indicatePessimisticFixpoint(); | |||
5640 | ||||
5641 | // If a candicate was found in this update, return CHANGED. | |||
5642 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED | |||
5643 | : ChangeStatus ::CHANGED; | |||
5644 | } | |||
5645 | ||||
5646 | /// See AbstractAttribute::trackStatistics() | |||
5647 | void trackStatistics() const override { | |||
5648 | STATS_DECLTRACK_FLOATING_ATTR(value_simplify){ static llvm::Statistic NumIRFloating_value_simplify = {"attributor" , "NumIRFloating_value_simplify", ("Number of floating values known to be '" "value_simplify" "'")};; ++(NumIRFloating_value_simplify); } | |||
5649 | } | |||
5650 | }; | |||
5651 | ||||
5652 | struct AAValueSimplifyFunction : AAValueSimplifyImpl { | |||
5653 | AAValueSimplifyFunction(const IRPosition &IRP, Attributor &A) | |||
5654 | : AAValueSimplifyImpl(IRP, A) {} | |||
5655 | ||||
5656 | /// See AbstractAttribute::initialize(...). | |||
5657 | void initialize(Attributor &A) override { | |||
5658 | SimplifiedAssociatedValue = nullptr; | |||
5659 | indicateOptimisticFixpoint(); | |||
5660 | } | |||
5661 | /// See AbstractAttribute::initialize(...). | |||
5662 | ChangeStatus updateImpl(Attributor &A) override { | |||
5663 | llvm_unreachable(__builtin_unreachable() | |||
5664 | "AAValueSimplify(Function|CallSite)::updateImpl will not be called")__builtin_unreachable(); | |||
5665 | } | |||
5666 | /// See AbstractAttribute::trackStatistics() | |||
5667 | void trackStatistics() const override { | |||
5668 | STATS_DECLTRACK_FN_ATTR(value_simplify){ static llvm::Statistic NumIRFunction_value_simplify = {"attributor" , "NumIRFunction_value_simplify", ("Number of " "functions" " marked '" "value_simplify" "'")};; ++(NumIRFunction_value_simplify); } | |||
5669 | } | |||
5670 | }; | |||
5671 | ||||
5672 | struct AAValueSimplifyCallSite : AAValueSimplifyFunction { | |||
5673 | AAValueSimplifyCallSite(const IRPosition &IRP, Attributor &A) | |||
5674 | : AAValueSimplifyFunction(IRP, A) {} | |||
5675 | /// See AbstractAttribute::trackStatistics() | |||
5676 | void trackStatistics() const override { | |||
5677 | STATS_DECLTRACK_CS_ATTR(value_simplify){ static llvm::Statistic NumIRCS_value_simplify = {"attributor" , "NumIRCS_value_simplify", ("Number of " "call site" " marked '" "value_simplify" "'")};; ++(NumIRCS_value_simplify); } | |||
5678 | } | |||
5679 | }; | |||
5680 | ||||
5681 | struct AAValueSimplifyCallSiteReturned : AAValueSimplifyImpl { | |||
5682 | AAValueSimplifyCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
5683 | : AAValueSimplifyImpl(IRP, A) {} | |||
5684 | ||||
5685 | void initialize(Attributor &A) override { | |||
5686 | AAValueSimplifyImpl::initialize(A); | |||
5687 | if (!getAssociatedFunction()) | |||
5688 | indicatePessimisticFixpoint(); | |||
5689 | } | |||
5690 | ||||
5691 | /// See AbstractAttribute::updateImpl(...). | |||
5692 | ChangeStatus updateImpl(Attributor &A) override { | |||
5693 | auto Before = SimplifiedAssociatedValue; | |||
5694 | auto &RetAA = A.getAAFor<AAReturnedValues>( | |||
5695 | *this, IRPosition::function(*getAssociatedFunction()), | |||
5696 | DepClassTy::REQUIRED); | |||
5697 | auto PredForReturned = | |||
5698 | [&](Value &RetVal, const SmallSetVector<ReturnInst *, 4> &RetInsts) { | |||
5699 | bool UsedAssumedInformation = false; | |||
5700 | Optional<Value *> CSRetVal = A.translateArgumentToCallSiteContent( | |||
5701 | &RetVal, *cast<CallBase>(getCtxI()), *this, | |||
5702 | UsedAssumedInformation); | |||
5703 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( | |||
5704 | SimplifiedAssociatedValue, CSRetVal, getAssociatedType()); | |||
5705 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); | |||
5706 | }; | |||
5707 | if (!RetAA.checkForAllReturnedValuesAndReturnInsts(PredForReturned)) | |||
5708 | if (!askSimplifiedValueForOtherAAs(A)) | |||
5709 | return indicatePessimisticFixpoint(); | |||
5710 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED | |||
5711 | : ChangeStatus ::CHANGED; | |||
5712 | } | |||
5713 | ||||
5714 | void trackStatistics() const override { | |||
5715 | STATS_DECLTRACK_CSRET_ATTR(value_simplify){ static llvm::Statistic NumIRCSReturn_value_simplify = {"attributor" , "NumIRCSReturn_value_simplify", ("Number of " "call site returns" " marked '" "value_simplify" "'")};; ++(NumIRCSReturn_value_simplify ); } | |||
5716 | } | |||
5717 | }; | |||
5718 | ||||
5719 | struct AAValueSimplifyCallSiteArgument : AAValueSimplifyFloating { | |||
5720 | AAValueSimplifyCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
5721 | : AAValueSimplifyFloating(IRP, A) {} | |||
5722 | ||||
5723 | /// See AbstractAttribute::manifest(...). | |||
5724 | ChangeStatus manifest(Attributor &A) override { | |||
5725 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
5726 | ||||
5727 | if (auto *NewV = getReplacementValue(A)) { | |||
5728 | Use &U = cast<CallBase>(&getAnchorValue()) | |||
5729 | ->getArgOperandUse(getCallSiteArgNo()); | |||
5730 | if (A.changeUseAfterManifest(U, *NewV)) | |||
5731 | Changed = ChangeStatus::CHANGED; | |||
5732 | } | |||
5733 | ||||
5734 | return Changed | AAValueSimplify::manifest(A); | |||
5735 | } | |||
5736 | ||||
5737 | void trackStatistics() const override { | |||
5738 | STATS_DECLTRACK_CSARG_ATTR(value_simplify){ static llvm::Statistic NumIRCSArguments_value_simplify = {"attributor" , "NumIRCSArguments_value_simplify", ("Number of " "call site arguments" " marked '" "value_simplify" "'")};; ++(NumIRCSArguments_value_simplify ); } | |||
5739 | } | |||
5740 | }; | |||
5741 | ||||
5742 | /// ----------------------- Heap-To-Stack Conversion --------------------------- | |||
5743 | struct AAHeapToStackFunction final : public AAHeapToStack { | |||
5744 | ||||
5745 | struct AllocationInfo { | |||
5746 | /// The call that allocates the memory. | |||
5747 | CallBase *const CB; | |||
5748 | ||||
5749 | /// The kind of allocation. | |||
5750 | const enum class AllocationKind { | |||
5751 | MALLOC, | |||
5752 | CALLOC, | |||
5753 | ALIGNED_ALLOC, | |||
5754 | } Kind; | |||
5755 | ||||
5756 | /// The library function id for the allocation. | |||
5757 | LibFunc LibraryFunctionId = NotLibFunc; | |||
5758 | ||||
5759 | /// The status wrt. a rewrite. | |||
5760 | enum { | |||
5761 | STACK_DUE_TO_USE, | |||
5762 | STACK_DUE_TO_FREE, | |||
5763 | INVALID, | |||
5764 | } Status = STACK_DUE_TO_USE; | |||
5765 | ||||
5766 | /// Flag to indicate if we encountered a use that might free this allocation | |||
5767 | /// but which is not in the deallocation infos. | |||
5768 | bool HasPotentiallyFreeingUnknownUses = false; | |||
5769 | ||||
5770 | /// The set of free calls that use this allocation. | |||
5771 | SmallPtrSet<CallBase *, 1> PotentialFreeCalls{}; | |||
5772 | }; | |||
5773 | ||||
5774 | struct DeallocationInfo { | |||
5775 | /// The call that deallocates the memory. | |||
5776 | CallBase *const CB; | |||
5777 | ||||
5778 | /// Flag to indicate if we don't know all objects this deallocation might | |||
5779 | /// free. | |||
5780 | bool MightFreeUnknownObjects = false; | |||
5781 | ||||
5782 | /// The set of allocation calls that are potentially freed. | |||
5783 | SmallPtrSet<CallBase *, 1> PotentialAllocationCalls{}; | |||
5784 | }; | |||
5785 | ||||
5786 | AAHeapToStackFunction(const IRPosition &IRP, Attributor &A) | |||
5787 | : AAHeapToStack(IRP, A) {} | |||
5788 | ||||
5789 | ~AAHeapToStackFunction() { | |||
5790 | // Ensure we call the destructor so we release any memory allocated in the | |||
5791 | // sets. | |||
5792 | for (auto &It : AllocationInfos) | |||
5793 | It.getSecond()->~AllocationInfo(); | |||
5794 | for (auto &It : DeallocationInfos) | |||
5795 | It.getSecond()->~DeallocationInfo(); | |||
5796 | } | |||
5797 | ||||
5798 | void initialize(Attributor &A) override { | |||
5799 | AAHeapToStack::initialize(A); | |||
5800 | ||||
5801 | const Function *F = getAnchorScope(); | |||
5802 | const auto *TLI = A.getInfoCache().getTargetLibraryInfoForFunction(*F); | |||
5803 | ||||
5804 | auto AllocationIdentifierCB = [&](Instruction &I) { | |||
5805 | CallBase *CB = dyn_cast<CallBase>(&I); | |||
5806 | if (!CB) | |||
5807 | return true; | |||
5808 | if (isFreeCall(CB, TLI)) { | |||
5809 | DeallocationInfos[CB] = new (A.Allocator) DeallocationInfo{CB}; | |||
5810 | return true; | |||
5811 | } | |||
5812 | bool IsMalloc = isMallocLikeFn(CB, TLI); | |||
5813 | bool IsAlignedAllocLike = !IsMalloc && isAlignedAllocLikeFn(CB, TLI); | |||
5814 | bool IsCalloc = | |||
5815 | !IsMalloc && !IsAlignedAllocLike && isCallocLikeFn(CB, TLI); | |||
5816 | if (!IsMalloc && !IsAlignedAllocLike && !IsCalloc) | |||
5817 | return true; | |||
5818 | auto Kind = | |||
5819 | IsMalloc ? AllocationInfo::AllocationKind::MALLOC | |||
5820 | : (IsCalloc ? AllocationInfo::AllocationKind::CALLOC | |||
5821 | : AllocationInfo::AllocationKind::ALIGNED_ALLOC); | |||
5822 | ||||
5823 | AllocationInfo *AI = new (A.Allocator) AllocationInfo{CB, Kind}; | |||
5824 | AllocationInfos[CB] = AI; | |||
5825 | TLI->getLibFunc(*CB, AI->LibraryFunctionId); | |||
5826 | return true; | |||
5827 | }; | |||
5828 | ||||
5829 | bool UsedAssumedInformation = false; | |||
5830 | bool Success = A.checkForAllCallLikeInstructions( | |||
5831 | AllocationIdentifierCB, *this, UsedAssumedInformation, | |||
5832 | /* CheckBBLivenessOnly */ false, | |||
5833 | /* CheckPotentiallyDead */ true); | |||
5834 | (void)Success; | |||
5835 | assert(Success && "Did not expect the call base visit callback to fail!")((void)0); | |||
5836 | } | |||
5837 | ||||
5838 | const std::string getAsStr() const override { | |||
5839 | unsigned NumH2SMallocs = 0, NumInvalidMallocs = 0; | |||
5840 | for (const auto &It : AllocationInfos) { | |||
5841 | if (It.second->Status == AllocationInfo::INVALID) | |||
5842 | ++NumInvalidMallocs; | |||
5843 | else | |||
5844 | ++NumH2SMallocs; | |||
5845 | } | |||
5846 | return "[H2S] Mallocs Good/Bad: " + std::to_string(NumH2SMallocs) + "/" + | |||
5847 | std::to_string(NumInvalidMallocs); | |||
5848 | } | |||
5849 | ||||
5850 | /// See AbstractAttribute::trackStatistics(). | |||
5851 | void trackStatistics() const override { | |||
5852 | STATS_DECL(static llvm::Statistic NumIRFunction_MallocCalls = {"attributor" , "NumIRFunction_MallocCalls", "Number of malloc/calloc/aligned_alloc calls converted to allocas" };; | |||
5853 | MallocCalls, Function,static llvm::Statistic NumIRFunction_MallocCalls = {"attributor" , "NumIRFunction_MallocCalls", "Number of malloc/calloc/aligned_alloc calls converted to allocas" };; | |||
5854 | "Number of malloc/calloc/aligned_alloc calls converted to allocas")static llvm::Statistic NumIRFunction_MallocCalls = {"attributor" , "NumIRFunction_MallocCalls", "Number of malloc/calloc/aligned_alloc calls converted to allocas" };;; | |||
5855 | for (auto &It : AllocationInfos) | |||
5856 | if (It.second->Status != AllocationInfo::INVALID) | |||
5857 | ++BUILD_STAT_NAME(MallocCalls, Function)NumIRFunction_MallocCalls; | |||
5858 | } | |||
5859 | ||||
5860 | bool isAssumedHeapToStack(const CallBase &CB) const override { | |||
5861 | if (isValidState()) | |||
5862 | if (AllocationInfo *AI = AllocationInfos.lookup(&CB)) | |||
5863 | return AI->Status != AllocationInfo::INVALID; | |||
5864 | return false; | |||
5865 | } | |||
5866 | ||||
5867 | bool isAssumedHeapToStackRemovedFree(CallBase &CB) const override { | |||
5868 | if (!isValidState()) | |||
5869 | return false; | |||
5870 | ||||
5871 | for (auto &It : AllocationInfos) { | |||
5872 | AllocationInfo &AI = *It.second; | |||
5873 | if (AI.Status == AllocationInfo::INVALID) | |||
5874 | continue; | |||
5875 | ||||
5876 | if (AI.PotentialFreeCalls.count(&CB)) | |||
5877 | return true; | |||
5878 | } | |||
5879 | ||||
5880 | return false; | |||
5881 | } | |||
5882 | ||||
5883 | ChangeStatus manifest(Attributor &A) override { | |||
5884 | assert(getState().isValidState() &&((void)0) | |||
5885 | "Attempted to manifest an invalid state!")((void)0); | |||
5886 | ||||
5887 | ChangeStatus HasChanged = ChangeStatus::UNCHANGED; | |||
5888 | Function *F = getAnchorScope(); | |||
5889 | const auto *TLI = A.getInfoCache().getTargetLibraryInfoForFunction(*F); | |||
5890 | ||||
5891 | for (auto &It : AllocationInfos) { | |||
5892 | AllocationInfo &AI = *It.second; | |||
5893 | if (AI.Status == AllocationInfo::INVALID) | |||
5894 | continue; | |||
5895 | ||||
5896 | for (CallBase *FreeCall : AI.PotentialFreeCalls) { | |||
5897 | LLVM_DEBUG(dbgs() << "H2S: Removing free call: " << *FreeCall << "\n")do { } while (false); | |||
5898 | A.deleteAfterManifest(*FreeCall); | |||
5899 | HasChanged = ChangeStatus::CHANGED; | |||
5900 | } | |||
5901 | ||||
5902 | LLVM_DEBUG(dbgs() << "H2S: Removing malloc-like call: " << *AI.CBdo { } while (false) | |||
5903 | << "\n")do { } while (false); | |||
5904 | ||||
5905 | auto Remark = [&](OptimizationRemark OR) { | |||
5906 | LibFunc IsAllocShared; | |||
5907 | if (TLI->getLibFunc(*AI.CB, IsAllocShared)) | |||
5908 | if (IsAllocShared == LibFunc___kmpc_alloc_shared) | |||
5909 | return OR << "Moving globalized variable to the stack."; | |||
5910 | return OR << "Moving memory allocation from the heap to the stack."; | |||
5911 | }; | |||
5912 | if (AI.LibraryFunctionId == LibFunc___kmpc_alloc_shared) | |||
5913 | A.emitRemark<OptimizationRemark>(AI.CB, "OMP110", Remark); | |||
5914 | else | |||
5915 | A.emitRemark<OptimizationRemark>(AI.CB, "HeapToStack", Remark); | |||
5916 | ||||
5917 | Value *Size; | |||
5918 | Optional<APInt> SizeAPI = getSize(A, *this, AI); | |||
5919 | if (SizeAPI.hasValue()) { | |||
5920 | Size = ConstantInt::get(AI.CB->getContext(), *SizeAPI); | |||
5921 | } else if (AI.Kind == AllocationInfo::AllocationKind::CALLOC) { | |||
5922 | auto *Num = AI.CB->getOperand(0); | |||
5923 | auto *SizeT = AI.CB->getOperand(1); | |||
5924 | IRBuilder<> B(AI.CB); | |||
5925 | Size = B.CreateMul(Num, SizeT, "h2s.calloc.size"); | |||
5926 | } else if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) { | |||
5927 | Size = AI.CB->getOperand(1); | |||
5928 | } else { | |||
5929 | Size = AI.CB->getOperand(0); | |||
5930 | } | |||
5931 | ||||
5932 | Align Alignment(1); | |||
5933 | if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) { | |||
5934 | Optional<APInt> AlignmentAPI = | |||
5935 | getAPInt(A, *this, *AI.CB->getArgOperand(0)); | |||
5936 | assert(AlignmentAPI.hasValue() &&((void)0) | |||
5937 | "Expected an alignment during manifest!")((void)0); | |||
5938 | Alignment = | |||
5939 | max(Alignment, MaybeAlign(AlignmentAPI.getValue().getZExtValue())); | |||
5940 | } | |||
5941 | ||||
5942 | unsigned AS = cast<PointerType>(AI.CB->getType())->getAddressSpace(); | |||
5943 | Instruction *Alloca = | |||
5944 | new AllocaInst(Type::getInt8Ty(F->getContext()), AS, Size, Alignment, | |||
5945 | "", AI.CB->getNextNode()); | |||
5946 | ||||
5947 | if (Alloca->getType() != AI.CB->getType()) | |||
5948 | Alloca = new BitCastInst(Alloca, AI.CB->getType(), "malloc_bc", | |||
5949 | Alloca->getNextNode()); | |||
5950 | ||||
5951 | A.changeValueAfterManifest(*AI.CB, *Alloca); | |||
5952 | ||||
5953 | if (auto *II = dyn_cast<InvokeInst>(AI.CB)) { | |||
5954 | auto *NBB = II->getNormalDest(); | |||
5955 | BranchInst::Create(NBB, AI.CB->getParent()); | |||
5956 | A.deleteAfterManifest(*AI.CB); | |||
5957 | } else { | |||
5958 | A.deleteAfterManifest(*AI.CB); | |||
5959 | } | |||
5960 | ||||
5961 | // Zero out the allocated memory if it was a calloc. | |||
5962 | if (AI.Kind == AllocationInfo::AllocationKind::CALLOC) { | |||
5963 | auto *BI = new BitCastInst(Alloca, AI.CB->getType(), "calloc_bc", | |||
5964 | Alloca->getNextNode()); | |||
5965 | Value *Ops[] = { | |||
5966 | BI, ConstantInt::get(F->getContext(), APInt(8, 0, false)), Size, | |||
5967 | ConstantInt::get(Type::getInt1Ty(F->getContext()), false)}; | |||
5968 | ||||
5969 | Type *Tys[] = {BI->getType(), AI.CB->getOperand(0)->getType()}; | |||
5970 | Module *M = F->getParent(); | |||
5971 | Function *Fn = Intrinsic::getDeclaration(M, Intrinsic::memset, Tys); | |||
5972 | CallInst::Create(Fn, Ops, "", BI->getNextNode()); | |||
5973 | } | |||
5974 | HasChanged = ChangeStatus::CHANGED; | |||
5975 | } | |||
5976 | ||||
5977 | return HasChanged; | |||
5978 | } | |||
5979 | ||||
5980 | Optional<APInt> getAPInt(Attributor &A, const AbstractAttribute &AA, | |||
5981 | Value &V) { | |||
5982 | bool UsedAssumedInformation = false; | |||
5983 | Optional<Constant *> SimpleV = | |||
5984 | A.getAssumedConstant(V, AA, UsedAssumedInformation); | |||
5985 | if (!SimpleV.hasValue()) | |||
5986 | return APInt(64, 0); | |||
5987 | if (auto *CI = dyn_cast_or_null<ConstantInt>(SimpleV.getValue())) | |||
5988 | return CI->getValue(); | |||
5989 | return llvm::None; | |||
5990 | } | |||
5991 | ||||
5992 | Optional<APInt> getSize(Attributor &A, const AbstractAttribute &AA, | |||
5993 | AllocationInfo &AI) { | |||
5994 | ||||
5995 | if (AI.Kind == AllocationInfo::AllocationKind::MALLOC) | |||
5996 | return getAPInt(A, AA, *AI.CB->getArgOperand(0)); | |||
5997 | ||||
5998 | if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) | |||
5999 | // Only if the alignment is also constant we return a size. | |||
6000 | return getAPInt(A, AA, *AI.CB->getArgOperand(0)).hasValue() | |||
6001 | ? getAPInt(A, AA, *AI.CB->getArgOperand(1)) | |||
6002 | : llvm::None; | |||
6003 | ||||
6004 | assert(AI.Kind == AllocationInfo::AllocationKind::CALLOC &&((void)0) | |||
6005 | "Expected only callocs are left")((void)0); | |||
6006 | Optional<APInt> Num = getAPInt(A, AA, *AI.CB->getArgOperand(0)); | |||
6007 | Optional<APInt> Size = getAPInt(A, AA, *AI.CB->getArgOperand(1)); | |||
6008 | if (!Num.hasValue() || !Size.hasValue()) | |||
6009 | return llvm::None; | |||
6010 | bool Overflow = false; | |||
6011 | Size = Size.getValue().umul_ov(Num.getValue(), Overflow); | |||
6012 | return Overflow ? llvm::None : Size; | |||
6013 | } | |||
6014 | ||||
6015 | /// Collection of all malloc-like calls in a function with associated | |||
6016 | /// information. | |||
6017 | DenseMap<CallBase *, AllocationInfo *> AllocationInfos; | |||
6018 | ||||
6019 | /// Collection of all free-like calls in a function with associated | |||
6020 | /// information. | |||
6021 | DenseMap<CallBase *, DeallocationInfo *> DeallocationInfos; | |||
6022 | ||||
6023 | ChangeStatus updateImpl(Attributor &A) override; | |||
6024 | }; | |||
6025 | ||||
6026 | ChangeStatus AAHeapToStackFunction::updateImpl(Attributor &A) { | |||
6027 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
6028 | const Function *F = getAnchorScope(); | |||
6029 | ||||
6030 | const auto &LivenessAA = | |||
6031 | A.getAAFor<AAIsDead>(*this, IRPosition::function(*F), DepClassTy::NONE); | |||
6032 | ||||
6033 | MustBeExecutedContextExplorer &Explorer = | |||
6034 | A.getInfoCache().getMustBeExecutedContextExplorer(); | |||
6035 | ||||
6036 | bool StackIsAccessibleByOtherThreads = | |||
6037 | A.getInfoCache().stackIsAccessibleByOtherThreads(); | |||
6038 | ||||
6039 | // Flag to ensure we update our deallocation information at most once per | |||
6040 | // updateImpl call and only if we use the free check reasoning. | |||
6041 | bool HasUpdatedFrees = false; | |||
6042 | ||||
6043 | auto UpdateFrees = [&]() { | |||
6044 | HasUpdatedFrees = true; | |||
6045 | ||||
6046 | for (auto &It : DeallocationInfos) { | |||
6047 | DeallocationInfo &DI = *It.second; | |||
6048 | // For now we cannot use deallocations that have unknown inputs, skip | |||
6049 | // them. | |||
6050 | if (DI.MightFreeUnknownObjects) | |||
6051 | continue; | |||
6052 | ||||
6053 | // No need to analyze dead calls, ignore them instead. | |||
6054 | bool UsedAssumedInformation = false; | |||
6055 | if (A.isAssumedDead(*DI.CB, this, &LivenessAA, UsedAssumedInformation, | |||
6056 | /* CheckBBLivenessOnly */ true)) | |||
6057 | continue; | |||
6058 | ||||
6059 | // Use the optimistic version to get the freed objects, ignoring dead | |||
6060 | // branches etc. | |||
6061 | SmallVector<Value *, 8> Objects; | |||
6062 | if (!AA::getAssumedUnderlyingObjects(A, *DI.CB->getArgOperand(0), Objects, | |||
6063 | *this, DI.CB)) { | |||
6064 | LLVM_DEBUG(do { } while (false) | |||
6065 | dbgs()do { } while (false) | |||
6066 | << "[H2S] Unexpected failure in getAssumedUnderlyingObjects!\n")do { } while (false); | |||
6067 | DI.MightFreeUnknownObjects = true; | |||
6068 | continue; | |||
6069 | } | |||
6070 | ||||
6071 | // Check each object explicitly. | |||
6072 | for (auto *Obj : Objects) { | |||
6073 | // Free of null and undef can be ignored as no-ops (or UB in the latter | |||
6074 | // case). | |||
6075 | if (isa<ConstantPointerNull>(Obj) || isa<UndefValue>(Obj)) | |||
6076 | continue; | |||
6077 | ||||
6078 | CallBase *ObjCB = dyn_cast<CallBase>(Obj); | |||
6079 | if (!ObjCB) { | |||
6080 | LLVM_DEBUG(dbgs()do { } while (false) | |||
6081 | << "[H2S] Free of a non-call object: " << *Obj << "\n")do { } while (false); | |||
6082 | DI.MightFreeUnknownObjects = true; | |||
6083 | continue; | |||
6084 | } | |||
6085 | ||||
6086 | AllocationInfo *AI = AllocationInfos.lookup(ObjCB); | |||
6087 | if (!AI) { | |||
6088 | LLVM_DEBUG(dbgs() << "[H2S] Free of a non-allocation object: " << *Objdo { } while (false) | |||
6089 | << "\n")do { } while (false); | |||
6090 | DI.MightFreeUnknownObjects = true; | |||
6091 | continue; | |||
6092 | } | |||
6093 | ||||
6094 | DI.PotentialAllocationCalls.insert(ObjCB); | |||
6095 | } | |||
6096 | } | |||
6097 | }; | |||
6098 | ||||
6099 | auto FreeCheck = [&](AllocationInfo &AI) { | |||
6100 | // If the stack is not accessible by other threads, the "must-free" logic | |||
6101 | // doesn't apply as the pointer could be shared and needs to be places in | |||
6102 | // "shareable" memory. | |||
6103 | if (!StackIsAccessibleByOtherThreads) { | |||
6104 | auto &NoSyncAA = | |||
6105 | A.getAAFor<AANoSync>(*this, getIRPosition(), DepClassTy::OPTIONAL); | |||
6106 | if (!NoSyncAA.isAssumedNoSync()) { | |||
6107 | LLVM_DEBUG(do { } while (false) | |||
6108 | dbgs() << "[H2S] found an escaping use, stack is not accessible by "do { } while (false) | |||
6109 | "other threads and function is not nosync:\n")do { } while (false); | |||
6110 | return false; | |||
6111 | } | |||
6112 | } | |||
6113 | if (!HasUpdatedFrees) | |||
6114 | UpdateFrees(); | |||
6115 | ||||
6116 | // TODO: Allow multi exit functions that have different free calls. | |||
6117 | if (AI.PotentialFreeCalls.size() != 1) { | |||
6118 | LLVM_DEBUG(dbgs() << "[H2S] did not find one free call but "do { } while (false) | |||
6119 | << AI.PotentialFreeCalls.size() << "\n")do { } while (false); | |||
6120 | return false; | |||
6121 | } | |||
6122 | CallBase *UniqueFree = *AI.PotentialFreeCalls.begin(); | |||
6123 | DeallocationInfo *DI = DeallocationInfos.lookup(UniqueFree); | |||
6124 | if (!DI) { | |||
6125 | LLVM_DEBUG(do { } while (false) | |||
6126 | dbgs() << "[H2S] unique free call was not known as deallocation call "do { } while (false) | |||
6127 | << *UniqueFree << "\n")do { } while (false); | |||
6128 | return false; | |||
6129 | } | |||
6130 | if (DI->MightFreeUnknownObjects) { | |||
6131 | LLVM_DEBUG(do { } while (false) | |||
6132 | dbgs() << "[H2S] unique free call might free unknown allocations\n")do { } while (false); | |||
6133 | return false; | |||
6134 | } | |||
6135 | if (DI->PotentialAllocationCalls.size() > 1) { | |||
6136 | LLVM_DEBUG(dbgs() << "[H2S] unique free call might free "do { } while (false) | |||
6137 | << DI->PotentialAllocationCalls.size()do { } while (false) | |||
6138 | << " different allocations\n")do { } while (false); | |||
6139 | return false; | |||
6140 | } | |||
6141 | if (*DI->PotentialAllocationCalls.begin() != AI.CB) { | |||
6142 | LLVM_DEBUG(do { } while (false) | |||
6143 | dbgs()do { } while (false) | |||
6144 | << "[H2S] unique free call not known to free this allocation but "do { } while (false) | |||
6145 | << **DI->PotentialAllocationCalls.begin() << "\n")do { } while (false); | |||
6146 | return false; | |||
6147 | } | |||
6148 | Instruction *CtxI = isa<InvokeInst>(AI.CB) ? AI.CB : AI.CB->getNextNode(); | |||
6149 | if (!Explorer.findInContextOf(UniqueFree, CtxI)) { | |||
6150 | LLVM_DEBUG(do { } while (false) | |||
6151 | dbgs()do { } while (false) | |||
6152 | << "[H2S] unique free call might not be executed with the allocation "do { } while (false) | |||
6153 | << *UniqueFree << "\n")do { } while (false); | |||
6154 | return false; | |||
6155 | } | |||
6156 | return true; | |||
6157 | }; | |||
6158 | ||||
6159 | auto UsesCheck = [&](AllocationInfo &AI) { | |||
6160 | bool ValidUsesOnly = true; | |||
6161 | ||||
6162 | auto Pred = [&](const Use &U, bool &Follow) -> bool { | |||
6163 | Instruction *UserI = cast<Instruction>(U.getUser()); | |||
6164 | if (isa<LoadInst>(UserI)) | |||
6165 | return true; | |||
6166 | if (auto *SI = dyn_cast<StoreInst>(UserI)) { | |||
6167 | if (SI->getValueOperand() == U.get()) { | |||
6168 | LLVM_DEBUG(dbgs()do { } while (false) | |||
6169 | << "[H2S] escaping store to memory: " << *UserI << "\n")do { } while (false); | |||
6170 | ValidUsesOnly = false; | |||
6171 | } else { | |||
6172 | // A store into the malloc'ed memory is fine. | |||
6173 | } | |||
6174 | return true; | |||
6175 | } | |||
6176 | if (auto *CB = dyn_cast<CallBase>(UserI)) { | |||
6177 | if (!CB->isArgOperand(&U) || CB->isLifetimeStartOrEnd()) | |||
6178 | return true; | |||
6179 | if (DeallocationInfos.count(CB)) { | |||
6180 | AI.PotentialFreeCalls.insert(CB); | |||
6181 | return true; | |||
6182 | } | |||
6183 | ||||
6184 | unsigned ArgNo = CB->getArgOperandNo(&U); | |||
6185 | ||||
6186 | const auto &NoCaptureAA = A.getAAFor<AANoCapture>( | |||
6187 | *this, IRPosition::callsite_argument(*CB, ArgNo), | |||
6188 | DepClassTy::OPTIONAL); | |||
6189 | ||||
6190 | // If a call site argument use is nofree, we are fine. | |||
6191 | const auto &ArgNoFreeAA = A.getAAFor<AANoFree>( | |||
6192 | *this, IRPosition::callsite_argument(*CB, ArgNo), | |||
6193 | DepClassTy::OPTIONAL); | |||
6194 | ||||
6195 | bool MaybeCaptured = !NoCaptureAA.isAssumedNoCapture(); | |||
6196 | bool MaybeFreed = !ArgNoFreeAA.isAssumedNoFree(); | |||
6197 | if (MaybeCaptured || | |||
6198 | (AI.LibraryFunctionId != LibFunc___kmpc_alloc_shared && | |||
6199 | MaybeFreed)) { | |||
6200 | AI.HasPotentiallyFreeingUnknownUses |= MaybeFreed; | |||
6201 | ||||
6202 | // Emit a missed remark if this is missed OpenMP globalization. | |||
6203 | auto Remark = [&](OptimizationRemarkMissed ORM) { | |||
6204 | return ORM | |||
6205 | << "Could not move globalized variable to the stack. " | |||
6206 | "Variable is potentially captured in call. Mark " | |||
6207 | "parameter as `__attribute__((noescape))` to override."; | |||
6208 | }; | |||
6209 | ||||
6210 | if (ValidUsesOnly && | |||
6211 | AI.LibraryFunctionId == LibFunc___kmpc_alloc_shared) | |||
6212 | A.emitRemark<OptimizationRemarkMissed>(AI.CB, "OMP113", Remark); | |||
6213 | ||||
6214 | LLVM_DEBUG(dbgs() << "[H2S] Bad user: " << *UserI << "\n")do { } while (false); | |||
6215 | ValidUsesOnly = false; | |||
6216 | } | |||
6217 | return true; | |||
6218 | } | |||
6219 | ||||
6220 | if (isa<GetElementPtrInst>(UserI) || isa<BitCastInst>(UserI) || | |||
6221 | isa<PHINode>(UserI) || isa<SelectInst>(UserI)) { | |||
6222 | Follow = true; | |||
6223 | return true; | |||
6224 | } | |||
6225 | // Unknown user for which we can not track uses further (in a way that | |||
6226 | // makes sense). | |||
6227 | LLVM_DEBUG(dbgs() << "[H2S] Unknown user: " << *UserI << "\n")do { } while (false); | |||
6228 | ValidUsesOnly = false; | |||
6229 | return true; | |||
6230 | }; | |||
6231 | if (!A.checkForAllUses(Pred, *this, *AI.CB)) | |||
6232 | return false; | |||
6233 | return ValidUsesOnly; | |||
6234 | }; | |||
6235 | ||||
6236 | // The actual update starts here. We look at all allocations and depending on | |||
6237 | // their status perform the appropriate check(s). | |||
6238 | for (auto &It : AllocationInfos) { | |||
6239 | AllocationInfo &AI = *It.second; | |||
6240 | if (AI.Status == AllocationInfo::INVALID) | |||
6241 | continue; | |||
6242 | ||||
6243 | if (MaxHeapToStackSize == -1) { | |||
6244 | if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) | |||
6245 | if (!getAPInt(A, *this, *AI.CB->getArgOperand(0)).hasValue()) { | |||
6246 | LLVM_DEBUG(dbgs() << "[H2S] Unknown allocation alignment: " << *AI.CBdo { } while (false) | |||
6247 | << "\n")do { } while (false); | |||
6248 | AI.Status = AllocationInfo::INVALID; | |||
6249 | Changed = ChangeStatus::CHANGED; | |||
6250 | continue; | |||
6251 | } | |||
6252 | } else { | |||
6253 | Optional<APInt> Size = getSize(A, *this, AI); | |||
6254 | if (!Size.hasValue() || Size.getValue().ugt(MaxHeapToStackSize)) { | |||
6255 | LLVM_DEBUG({do { } while (false) | |||
6256 | if (!Size.hasValue())do { } while (false) | |||
6257 | dbgs() << "[H2S] Unknown allocation size (or alignment): " << *AI.CBdo { } while (false) | |||
6258 | << "\n";do { } while (false) | |||
6259 | elsedo { } while (false) | |||
6260 | dbgs() << "[H2S] Allocation size too large: " << *AI.CB << " vs. "do { } while (false) | |||
6261 | << MaxHeapToStackSize << "\n";do { } while (false) | |||
6262 | })do { } while (false); | |||
6263 | ||||
6264 | AI.Status = AllocationInfo::INVALID; | |||
6265 | Changed = ChangeStatus::CHANGED; | |||
6266 | continue; | |||
6267 | } | |||
6268 | } | |||
6269 | ||||
6270 | switch (AI.Status) { | |||
6271 | case AllocationInfo::STACK_DUE_TO_USE: | |||
6272 | if (UsesCheck(AI)) | |||
6273 | continue; | |||
6274 | AI.Status = AllocationInfo::STACK_DUE_TO_FREE; | |||
6275 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; | |||
6276 | case AllocationInfo::STACK_DUE_TO_FREE: | |||
6277 | if (FreeCheck(AI)) | |||
6278 | continue; | |||
6279 | AI.Status = AllocationInfo::INVALID; | |||
6280 | Changed = ChangeStatus::CHANGED; | |||
6281 | continue; | |||
6282 | case AllocationInfo::INVALID: | |||
6283 | llvm_unreachable("Invalid allocations should never reach this point!")__builtin_unreachable(); | |||
6284 | }; | |||
6285 | } | |||
6286 | ||||
6287 | return Changed; | |||
6288 | } | |||
6289 | ||||
6290 | /// ----------------------- Privatizable Pointers ------------------------------ | |||
6291 | struct AAPrivatizablePtrImpl : public AAPrivatizablePtr { | |||
6292 | AAPrivatizablePtrImpl(const IRPosition &IRP, Attributor &A) | |||
6293 | : AAPrivatizablePtr(IRP, A), PrivatizableType(llvm::None) {} | |||
6294 | ||||
6295 | ChangeStatus indicatePessimisticFixpoint() override { | |||
6296 | AAPrivatizablePtr::indicatePessimisticFixpoint(); | |||
6297 | PrivatizableType = nullptr; | |||
6298 | return ChangeStatus::CHANGED; | |||
6299 | } | |||
6300 | ||||
6301 | /// Identify the type we can chose for a private copy of the underlying | |||
6302 | /// argument. None means it is not clear yet, nullptr means there is none. | |||
6303 | virtual Optional<Type *> identifyPrivatizableType(Attributor &A) = 0; | |||
6304 | ||||
6305 | /// Return a privatizable type that encloses both T0 and T1. | |||
6306 | /// TODO: This is merely a stub for now as we should manage a mapping as well. | |||
6307 | Optional<Type *> combineTypes(Optional<Type *> T0, Optional<Type *> T1) { | |||
6308 | if (!T0.hasValue()) | |||
6309 | return T1; | |||
6310 | if (!T1.hasValue()) | |||
6311 | return T0; | |||
6312 | if (T0 == T1) | |||
6313 | return T0; | |||
6314 | return nullptr; | |||
6315 | } | |||
6316 | ||||
6317 | Optional<Type *> getPrivatizableType() const override { | |||
6318 | return PrivatizableType; | |||
6319 | } | |||
6320 | ||||
6321 | const std::string getAsStr() const override { | |||
6322 | return isAssumedPrivatizablePtr() ? "[priv]" : "[no-priv]"; | |||
6323 | } | |||
6324 | ||||
6325 | protected: | |||
6326 | Optional<Type *> PrivatizableType; | |||
6327 | }; | |||
6328 | ||||
6329 | // TODO: Do this for call site arguments (probably also other values) as well. | |||
6330 | ||||
6331 | struct AAPrivatizablePtrArgument final : public AAPrivatizablePtrImpl { | |||
6332 | AAPrivatizablePtrArgument(const IRPosition &IRP, Attributor &A) | |||
6333 | : AAPrivatizablePtrImpl(IRP, A) {} | |||
6334 | ||||
6335 | /// See AAPrivatizablePtrImpl::identifyPrivatizableType(...) | |||
6336 | Optional<Type *> identifyPrivatizableType(Attributor &A) override { | |||
6337 | // If this is a byval argument and we know all the call sites (so we can | |||
6338 | // rewrite them), there is no need to check them explicitly. | |||
6339 | bool AllCallSitesKnown; | |||
6340 | if (getIRPosition().hasAttr(Attribute::ByVal) && | |||
6341 | A.checkForAllCallSites([](AbstractCallSite ACS) { return true; }, *this, | |||
6342 | true, AllCallSitesKnown)) | |||
6343 | return getAssociatedValue().getType()->getPointerElementType(); | |||
6344 | ||||
6345 | Optional<Type *> Ty; | |||
6346 | unsigned ArgNo = getIRPosition().getCallSiteArgNo(); | |||
6347 | ||||
6348 | // Make sure the associated call site argument has the same type at all call | |||
6349 | // sites and it is an allocation we know is safe to privatize, for now that | |||
6350 | // means we only allow alloca instructions. | |||
6351 | // TODO: We can additionally analyze the accesses in the callee to create | |||
6352 | // the type from that information instead. That is a little more | |||
6353 | // involved and will be done in a follow up patch. | |||
6354 | auto CallSiteCheck = [&](AbstractCallSite ACS) { | |||
6355 | IRPosition ACSArgPos = IRPosition::callsite_argument(ACS, ArgNo); | |||
6356 | // Check if a coresponding argument was found or if it is one not | |||
6357 | // associated (which can happen for callback calls). | |||
6358 | if (ACSArgPos.getPositionKind() == IRPosition::IRP_INVALID) | |||
6359 | return false; | |||
6360 | ||||
6361 | // Check that all call sites agree on a type. | |||
6362 | auto &PrivCSArgAA = | |||
6363 | A.getAAFor<AAPrivatizablePtr>(*this, ACSArgPos, DepClassTy::REQUIRED); | |||
6364 | Optional<Type *> CSTy = PrivCSArgAA.getPrivatizableType(); | |||
6365 | ||||
6366 | LLVM_DEBUG({do { } while (false) | |||
6367 | dbgs() << "[AAPrivatizablePtr] ACSPos: " << ACSArgPos << ", CSTy: ";do { } while (false) | |||
6368 | if (CSTy.hasValue() && CSTy.getValue())do { } while (false) | |||
6369 | CSTy.getValue()->print(dbgs());do { } while (false) | |||
6370 | else if (CSTy.hasValue())do { } while (false) | |||
6371 | dbgs() << "<nullptr>";do { } while (false) | |||
6372 | elsedo { } while (false) | |||
6373 | dbgs() << "<none>";do { } while (false) | |||
6374 | })do { } while (false); | |||
6375 | ||||
6376 | Ty = combineTypes(Ty, CSTy); | |||
6377 | ||||
6378 | LLVM_DEBUG({do { } while (false) | |||
6379 | dbgs() << " : New Type: ";do { } while (false) | |||
6380 | if (Ty.hasValue() && Ty.getValue())do { } while (false) | |||
6381 | Ty.getValue()->print(dbgs());do { } while (false) | |||
6382 | else if (Ty.hasValue())do { } while (false) | |||
6383 | dbgs() << "<nullptr>";do { } while (false) | |||
6384 | elsedo { } while (false) | |||
6385 | dbgs() << "<none>";do { } while (false) | |||
6386 | dbgs() << "\n";do { } while (false) | |||
6387 | })do { } while (false); | |||
6388 | ||||
6389 | return !Ty.hasValue() || Ty.getValue(); | |||
6390 | }; | |||
6391 | ||||
6392 | if (!A.checkForAllCallSites(CallSiteCheck, *this, true, AllCallSitesKnown)) | |||
6393 | return nullptr; | |||
6394 | return Ty; | |||
6395 | } | |||
6396 | ||||
6397 | /// See AbstractAttribute::updateImpl(...). | |||
6398 | ChangeStatus updateImpl(Attributor &A) override { | |||
6399 | PrivatizableType = identifyPrivatizableType(A); | |||
6400 | if (!PrivatizableType.hasValue()) | |||
6401 | return ChangeStatus::UNCHANGED; | |||
6402 | if (!PrivatizableType.getValue()) | |||
6403 | return indicatePessimisticFixpoint(); | |||
6404 | ||||
6405 | // The dependence is optional so we don't give up once we give up on the | |||
6406 | // alignment. | |||
6407 | A.getAAFor<AAAlign>(*this, IRPosition::value(getAssociatedValue()), | |||
6408 | DepClassTy::OPTIONAL); | |||
6409 | ||||
6410 | // Avoid arguments with padding for now. | |||
6411 | if (!getIRPosition().hasAttr(Attribute::ByVal) && | |||
6412 | !ArgumentPromotionPass::isDenselyPacked(PrivatizableType.getValue(), | |||
6413 | A.getInfoCache().getDL())) { | |||
6414 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] Padding detected\n")do { } while (false); | |||
6415 | return indicatePessimisticFixpoint(); | |||
6416 | } | |||
6417 | ||||
6418 | // Verify callee and caller agree on how the promoted argument would be | |||
6419 | // passed. | |||
6420 | // TODO: The use of the ArgumentPromotion interface here is ugly, we need a | |||
6421 | // specialized form of TargetTransformInfo::areFunctionArgsABICompatible | |||
6422 | // which doesn't require the arguments ArgumentPromotion wanted to pass. | |||
6423 | Function &Fn = *getIRPosition().getAnchorScope(); | |||
6424 | SmallPtrSet<Argument *, 1> ArgsToPromote, Dummy; | |||
6425 | ArgsToPromote.insert(getAssociatedArgument()); | |||
6426 | const auto *TTI = | |||
6427 | A.getInfoCache().getAnalysisResultForFunction<TargetIRAnalysis>(Fn); | |||
6428 | if (!TTI || | |||
6429 | !ArgumentPromotionPass::areFunctionArgsABICompatible( | |||
6430 | Fn, *TTI, ArgsToPromote, Dummy) || | |||
6431 | ArgsToPromote.empty()) { | |||
6432 | LLVM_DEBUG(do { } while (false) | |||
6433 | dbgs() << "[AAPrivatizablePtr] ABI incompatibility detected for "do { } while (false) | |||
6434 | << Fn.getName() << "\n")do { } while (false); | |||
6435 | return indicatePessimisticFixpoint(); | |||
6436 | } | |||
6437 | ||||
6438 | // Collect the types that will replace the privatizable type in the function | |||
6439 | // signature. | |||
6440 | SmallVector<Type *, 16> ReplacementTypes; | |||
6441 | identifyReplacementTypes(PrivatizableType.getValue(), ReplacementTypes); | |||
6442 | ||||
6443 | // Register a rewrite of the argument. | |||
6444 | Argument *Arg = getAssociatedArgument(); | |||
6445 | if (!A.isValidFunctionSignatureRewrite(*Arg, ReplacementTypes)) { | |||
6446 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] Rewrite not valid\n")do { } while (false); | |||
6447 | return indicatePessimisticFixpoint(); | |||
6448 | } | |||
6449 | ||||
6450 | unsigned ArgNo = Arg->getArgNo(); | |||
6451 | ||||
6452 | // Helper to check if for the given call site the associated argument is | |||
6453 | // passed to a callback where the privatization would be different. | |||
6454 | auto IsCompatiblePrivArgOfCallback = [&](CallBase &CB) { | |||
6455 | SmallVector<const Use *, 4> CallbackUses; | |||
6456 | AbstractCallSite::getCallbackUses(CB, CallbackUses); | |||
6457 | for (const Use *U : CallbackUses) { | |||
6458 | AbstractCallSite CBACS(U); | |||
6459 | assert(CBACS && CBACS.isCallbackCall())((void)0); | |||
6460 | for (Argument &CBArg : CBACS.getCalledFunction()->args()) { | |||
6461 | int CBArgNo = CBACS.getCallArgOperandNo(CBArg); | |||
6462 | ||||
6463 | LLVM_DEBUG({do { } while (false) | |||
6464 | dbgs()do { } while (false) | |||
6465 | << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) | |||
6466 | << "check if can be privatized in the context of its parent ("do { } while (false) | |||
6467 | << Arg->getParent()->getName()do { } while (false) | |||
6468 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) | |||
6469 | "callback ("do { } while (false) | |||
6470 | << CBArgNo << "@" << CBACS.getCalledFunction()->getName()do { } while (false) | |||
6471 | << ")\n[AAPrivatizablePtr] " << CBArg << " : "do { } while (false) | |||
6472 | << CBACS.getCallArgOperand(CBArg) << " vs "do { } while (false) | |||
6473 | << CB.getArgOperand(ArgNo) << "\n"do { } while (false) | |||
6474 | << "[AAPrivatizablePtr] " << CBArg << " : "do { } while (false) | |||
6475 | << CBACS.getCallArgOperandNo(CBArg) << " vs " << ArgNo << "\n";do { } while (false) | |||
6476 | })do { } while (false); | |||
6477 | ||||
6478 | if (CBArgNo != int(ArgNo)) | |||
6479 | continue; | |||
6480 | const auto &CBArgPrivAA = A.getAAFor<AAPrivatizablePtr>( | |||
6481 | *this, IRPosition::argument(CBArg), DepClassTy::REQUIRED); | |||
6482 | if (CBArgPrivAA.isValidState()) { | |||
6483 | auto CBArgPrivTy = CBArgPrivAA.getPrivatizableType(); | |||
6484 | if (!CBArgPrivTy.hasValue()) | |||
6485 | continue; | |||
6486 | if (CBArgPrivTy.getValue() == PrivatizableType) | |||
6487 | continue; | |||
6488 | } | |||
6489 | ||||
6490 | LLVM_DEBUG({do { } while (false) | |||
6491 | dbgs() << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) | |||
6492 | << " cannot be privatized in the context of its parent ("do { } while (false) | |||
6493 | << Arg->getParent()->getName()do { } while (false) | |||
6494 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) | |||
6495 | "callback ("do { } while (false) | |||
6496 | << CBArgNo << "@" << CBACS.getCalledFunction()->getName()do { } while (false) | |||
6497 | << ").\n[AAPrivatizablePtr] for which the argument "do { } while (false) | |||
6498 | "privatization is not compatible.\n";do { } while (false) | |||
6499 | })do { } while (false); | |||
6500 | return false; | |||
6501 | } | |||
6502 | } | |||
6503 | return true; | |||
6504 | }; | |||
6505 | ||||
6506 | // Helper to check if for the given call site the associated argument is | |||
6507 | // passed to a direct call where the privatization would be different. | |||
6508 | auto IsCompatiblePrivArgOfDirectCS = [&](AbstractCallSite ACS) { | |||
6509 | CallBase *DC = cast<CallBase>(ACS.getInstruction()); | |||
6510 | int DCArgNo = ACS.getCallArgOperandNo(ArgNo); | |||
6511 | assert(DCArgNo >= 0 && unsigned(DCArgNo) < DC->getNumArgOperands() &&((void)0) | |||
6512 | "Expected a direct call operand for callback call operand")((void)0); | |||
6513 | ||||
6514 | LLVM_DEBUG({do { } while (false) | |||
6515 | dbgs() << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) | |||
6516 | << " check if be privatized in the context of its parent ("do { } while (false) | |||
6517 | << Arg->getParent()->getName()do { } while (false) | |||
6518 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) | |||
6519 | "direct call of ("do { } while (false) | |||
6520 | << DCArgNo << "@" << DC->getCalledFunction()->getName()do { } while (false) | |||
6521 | << ").\n";do { } while (false) | |||
6522 | })do { } while (false); | |||
6523 | ||||
6524 | Function *DCCallee = DC->getCalledFunction(); | |||
6525 | if (unsigned(DCArgNo) < DCCallee->arg_size()) { | |||
6526 | const auto &DCArgPrivAA = A.getAAFor<AAPrivatizablePtr>( | |||
6527 | *this, IRPosition::argument(*DCCallee->getArg(DCArgNo)), | |||
6528 | DepClassTy::REQUIRED); | |||
6529 | if (DCArgPrivAA.isValidState()) { | |||
6530 | auto DCArgPrivTy = DCArgPrivAA.getPrivatizableType(); | |||
6531 | if (!DCArgPrivTy.hasValue()) | |||
6532 | return true; | |||
6533 | if (DCArgPrivTy.getValue() == PrivatizableType) | |||
6534 | return true; | |||
6535 | } | |||
6536 | } | |||
6537 | ||||
6538 | LLVM_DEBUG({do { } while (false) | |||
6539 | dbgs() << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) | |||
6540 | << " cannot be privatized in the context of its parent ("do { } while (false) | |||
6541 | << Arg->getParent()->getName()do { } while (false) | |||
6542 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) | |||
6543 | "direct call of ("do { } while (false) | |||
6544 | << ACS.getInstruction()->getCalledFunction()->getName()do { } while (false) | |||
6545 | << ").\n[AAPrivatizablePtr] for which the argument "do { } while (false) | |||
6546 | "privatization is not compatible.\n";do { } while (false) | |||
6547 | })do { } while (false); | |||
6548 | return false; | |||
6549 | }; | |||
6550 | ||||
6551 | // Helper to check if the associated argument is used at the given abstract | |||
6552 | // call site in a way that is incompatible with the privatization assumed | |||
6553 | // here. | |||
6554 | auto IsCompatiblePrivArgOfOtherCallSite = [&](AbstractCallSite ACS) { | |||
6555 | if (ACS.isDirectCall()) | |||
6556 | return IsCompatiblePrivArgOfCallback(*ACS.getInstruction()); | |||
6557 | if (ACS.isCallbackCall()) | |||
6558 | return IsCompatiblePrivArgOfDirectCS(ACS); | |||
6559 | return false; | |||
6560 | }; | |||
6561 | ||||
6562 | bool AllCallSitesKnown; | |||
6563 | if (!A.checkForAllCallSites(IsCompatiblePrivArgOfOtherCallSite, *this, true, | |||
6564 | AllCallSitesKnown)) | |||
6565 | return indicatePessimisticFixpoint(); | |||
6566 | ||||
6567 | return ChangeStatus::UNCHANGED; | |||
6568 | } | |||
6569 | ||||
6570 | /// Given a type to private \p PrivType, collect the constituates (which are | |||
6571 | /// used) in \p ReplacementTypes. | |||
6572 | static void | |||
6573 | identifyReplacementTypes(Type *PrivType, | |||
6574 | SmallVectorImpl<Type *> &ReplacementTypes) { | |||
6575 | // TODO: For now we expand the privatization type to the fullest which can | |||
6576 | // lead to dead arguments that need to be removed later. | |||
6577 | assert(PrivType && "Expected privatizable type!")((void)0); | |||
6578 | ||||
6579 | // Traverse the type, extract constituate types on the outermost level. | |||
6580 | if (auto *PrivStructType = dyn_cast<StructType>(PrivType)) { | |||
6581 | for (unsigned u = 0, e = PrivStructType->getNumElements(); u < e; u++) | |||
6582 | ReplacementTypes.push_back(PrivStructType->getElementType(u)); | |||
6583 | } else if (auto *PrivArrayType = dyn_cast<ArrayType>(PrivType)) { | |||
6584 | ReplacementTypes.append(PrivArrayType->getNumElements(), | |||
6585 | PrivArrayType->getElementType()); | |||
6586 | } else { | |||
6587 | ReplacementTypes.push_back(PrivType); | |||
6588 | } | |||
6589 | } | |||
6590 | ||||
6591 | /// Initialize \p Base according to the type \p PrivType at position \p IP. | |||
6592 | /// The values needed are taken from the arguments of \p F starting at | |||
6593 | /// position \p ArgNo. | |||
6594 | static void createInitialization(Type *PrivType, Value &Base, Function &F, | |||
6595 | unsigned ArgNo, Instruction &IP) { | |||
6596 | assert(PrivType && "Expected privatizable type!")((void)0); | |||
6597 | ||||
6598 | IRBuilder<NoFolder> IRB(&IP); | |||
6599 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
6600 | ||||
6601 | // Traverse the type, build GEPs and stores. | |||
6602 | if (auto *PrivStructType = dyn_cast<StructType>(PrivType)) { | |||
6603 | const StructLayout *PrivStructLayout = DL.getStructLayout(PrivStructType); | |||
6604 | for (unsigned u = 0, e = PrivStructType->getNumElements(); u < e; u++) { | |||
6605 | Type *PointeeTy = PrivStructType->getElementType(u)->getPointerTo(); | |||
6606 | Value *Ptr = | |||
6607 | constructPointer(PointeeTy, PrivType, &Base, | |||
6608 | PrivStructLayout->getElementOffset(u), IRB, DL); | |||
6609 | new StoreInst(F.getArg(ArgNo + u), Ptr, &IP); | |||
6610 | } | |||
6611 | } else if (auto *PrivArrayType = dyn_cast<ArrayType>(PrivType)) { | |||
6612 | Type *PointeeTy = PrivArrayType->getElementType(); | |||
6613 | Type *PointeePtrTy = PointeeTy->getPointerTo(); | |||
6614 | uint64_t PointeeTySize = DL.getTypeStoreSize(PointeeTy); | |||
6615 | for (unsigned u = 0, e = PrivArrayType->getNumElements(); u < e; u++) { | |||
6616 | Value *Ptr = constructPointer(PointeePtrTy, PrivType, &Base, | |||
6617 | u * PointeeTySize, IRB, DL); | |||
6618 | new StoreInst(F.getArg(ArgNo + u), Ptr, &IP); | |||
6619 | } | |||
6620 | } else { | |||
6621 | new StoreInst(F.getArg(ArgNo), &Base, &IP); | |||
6622 | } | |||
6623 | } | |||
6624 | ||||
6625 | /// Extract values from \p Base according to the type \p PrivType at the | |||
6626 | /// call position \p ACS. The values are appended to \p ReplacementValues. | |||
6627 | void createReplacementValues(Align Alignment, Type *PrivType, | |||
6628 | AbstractCallSite ACS, Value *Base, | |||
6629 | SmallVectorImpl<Value *> &ReplacementValues) { | |||
6630 | assert(Base && "Expected base value!")((void)0); | |||
6631 | assert(PrivType && "Expected privatizable type!")((void)0); | |||
6632 | Instruction *IP = ACS.getInstruction(); | |||
6633 | ||||
6634 | IRBuilder<NoFolder> IRB(IP); | |||
6635 | const DataLayout &DL = IP->getModule()->getDataLayout(); | |||
6636 | ||||
6637 | if (Base->getType()->getPointerElementType() != PrivType) | |||
6638 | Base = BitCastInst::CreateBitOrPointerCast(Base, PrivType->getPointerTo(), | |||
6639 | "", ACS.getInstruction()); | |||
6640 | ||||
6641 | // Traverse the type, build GEPs and loads. | |||
6642 | if (auto *PrivStructType = dyn_cast<StructType>(PrivType)) { | |||
6643 | const StructLayout *PrivStructLayout = DL.getStructLayout(PrivStructType); | |||
6644 | for (unsigned u = 0, e = PrivStructType->getNumElements(); u < e; u++) { | |||
6645 | Type *PointeeTy = PrivStructType->getElementType(u); | |||
6646 | Value *Ptr = | |||
6647 | constructPointer(PointeeTy->getPointerTo(), PrivType, Base, | |||
6648 | PrivStructLayout->getElementOffset(u), IRB, DL); | |||
6649 | LoadInst *L = new LoadInst(PointeeTy, Ptr, "", IP); | |||
6650 | L->setAlignment(Alignment); | |||
6651 | ReplacementValues.push_back(L); | |||
6652 | } | |||
6653 | } else if (auto *PrivArrayType = dyn_cast<ArrayType>(PrivType)) { | |||
6654 | Type *PointeeTy = PrivArrayType->getElementType(); | |||
6655 | uint64_t PointeeTySize = DL.getTypeStoreSize(PointeeTy); | |||
6656 | Type *PointeePtrTy = PointeeTy->getPointerTo(); | |||
6657 | for (unsigned u = 0, e = PrivArrayType->getNumElements(); u < e; u++) { | |||
6658 | Value *Ptr = constructPointer(PointeePtrTy, PrivType, Base, | |||
6659 | u * PointeeTySize, IRB, DL); | |||
6660 | LoadInst *L = new LoadInst(PointeeTy, Ptr, "", IP); | |||
6661 | L->setAlignment(Alignment); | |||
6662 | ReplacementValues.push_back(L); | |||
6663 | } | |||
6664 | } else { | |||
6665 | LoadInst *L = new LoadInst(PrivType, Base, "", IP); | |||
6666 | L->setAlignment(Alignment); | |||
6667 | ReplacementValues.push_back(L); | |||
6668 | } | |||
6669 | } | |||
6670 | ||||
6671 | /// See AbstractAttribute::manifest(...) | |||
6672 | ChangeStatus manifest(Attributor &A) override { | |||
6673 | if (!PrivatizableType.hasValue()) | |||
6674 | return ChangeStatus::UNCHANGED; | |||
6675 | assert(PrivatizableType.getValue() && "Expected privatizable type!")((void)0); | |||
6676 | ||||
6677 | // Collect all tail calls in the function as we cannot allow new allocas to | |||
6678 | // escape into tail recursion. | |||
6679 | // TODO: Be smarter about new allocas escaping into tail calls. | |||
6680 | SmallVector<CallInst *, 16> TailCalls; | |||
6681 | bool UsedAssumedInformation = false; | |||
6682 | if (!A.checkForAllInstructions( | |||
6683 | [&](Instruction &I) { | |||
6684 | CallInst &CI = cast<CallInst>(I); | |||
6685 | if (CI.isTailCall()) | |||
6686 | TailCalls.push_back(&CI); | |||
6687 | return true; | |||
6688 | }, | |||
6689 | *this, {Instruction::Call}, UsedAssumedInformation)) | |||
6690 | return ChangeStatus::UNCHANGED; | |||
6691 | ||||
6692 | Argument *Arg = getAssociatedArgument(); | |||
6693 | // Query AAAlign attribute for alignment of associated argument to | |||
6694 | // determine the best alignment of loads. | |||
6695 | const auto &AlignAA = | |||
6696 | A.getAAFor<AAAlign>(*this, IRPosition::value(*Arg), DepClassTy::NONE); | |||
6697 | ||||
6698 | // Callback to repair the associated function. A new alloca is placed at the | |||
6699 | // beginning and initialized with the values passed through arguments. The | |||
6700 | // new alloca replaces the use of the old pointer argument. | |||
6701 | Attributor::ArgumentReplacementInfo::CalleeRepairCBTy FnRepairCB = | |||
6702 | [=](const Attributor::ArgumentReplacementInfo &ARI, | |||
6703 | Function &ReplacementFn, Function::arg_iterator ArgIt) { | |||
6704 | BasicBlock &EntryBB = ReplacementFn.getEntryBlock(); | |||
6705 | Instruction *IP = &*EntryBB.getFirstInsertionPt(); | |||
6706 | Instruction *AI = new AllocaInst(PrivatizableType.getValue(), 0, | |||
6707 | Arg->getName() + ".priv", IP); | |||
6708 | createInitialization(PrivatizableType.getValue(), *AI, ReplacementFn, | |||
6709 | ArgIt->getArgNo(), *IP); | |||
6710 | ||||
6711 | if (AI->getType() != Arg->getType()) | |||
6712 | AI = | |||
6713 | BitCastInst::CreateBitOrPointerCast(AI, Arg->getType(), "", IP); | |||
6714 | Arg->replaceAllUsesWith(AI); | |||
6715 | ||||
6716 | for (CallInst *CI : TailCalls) | |||
6717 | CI->setTailCall(false); | |||
6718 | }; | |||
6719 | ||||
6720 | // Callback to repair a call site of the associated function. The elements | |||
6721 | // of the privatizable type are loaded prior to the call and passed to the | |||
6722 | // new function version. | |||
6723 | Attributor::ArgumentReplacementInfo::ACSRepairCBTy ACSRepairCB = | |||
6724 | [=, &AlignAA](const Attributor::ArgumentReplacementInfo &ARI, | |||
6725 | AbstractCallSite ACS, | |||
6726 | SmallVectorImpl<Value *> &NewArgOperands) { | |||
6727 | // When no alignment is specified for the load instruction, | |||
6728 | // natural alignment is assumed. | |||
6729 | createReplacementValues( | |||
6730 | assumeAligned(AlignAA.getAssumedAlign()), | |||
6731 | PrivatizableType.getValue(), ACS, | |||
6732 | ACS.getCallArgOperand(ARI.getReplacedArg().getArgNo()), | |||
6733 | NewArgOperands); | |||
6734 | }; | |||
6735 | ||||
6736 | // Collect the types that will replace the privatizable type in the function | |||
6737 | // signature. | |||
6738 | SmallVector<Type *, 16> ReplacementTypes; | |||
6739 | identifyReplacementTypes(PrivatizableType.getValue(), ReplacementTypes); | |||
6740 | ||||
6741 | // Register a rewrite of the argument. | |||
6742 | if (A.registerFunctionSignatureRewrite(*Arg, ReplacementTypes, | |||
6743 | std::move(FnRepairCB), | |||
6744 | std::move(ACSRepairCB))) | |||
6745 | return ChangeStatus::CHANGED; | |||
6746 | return ChangeStatus::UNCHANGED; | |||
6747 | } | |||
6748 | ||||
6749 | /// See AbstractAttribute::trackStatistics() | |||
6750 | void trackStatistics() const override { | |||
6751 | STATS_DECLTRACK_ARG_ATTR(privatizable_ptr){ static llvm::Statistic NumIRArguments_privatizable_ptr = {"attributor" , "NumIRArguments_privatizable_ptr", ("Number of " "arguments" " marked '" "privatizable_ptr" "'")};; ++(NumIRArguments_privatizable_ptr ); }; | |||
6752 | } | |||
6753 | }; | |||
6754 | ||||
6755 | struct AAPrivatizablePtrFloating : public AAPrivatizablePtrImpl { | |||
6756 | AAPrivatizablePtrFloating(const IRPosition &IRP, Attributor &A) | |||
6757 | : AAPrivatizablePtrImpl(IRP, A) {} | |||
6758 | ||||
6759 | /// See AbstractAttribute::initialize(...). | |||
6760 | virtual void initialize(Attributor &A) override { | |||
6761 | // TODO: We can privatize more than arguments. | |||
6762 | indicatePessimisticFixpoint(); | |||
6763 | } | |||
6764 | ||||
6765 | ChangeStatus updateImpl(Attributor &A) override { | |||
6766 | llvm_unreachable("AAPrivatizablePtr(Floating|Returned|CallSiteReturned)::"__builtin_unreachable() | |||
6767 | "updateImpl will not be called")__builtin_unreachable(); | |||
6768 | } | |||
6769 | ||||
6770 | /// See AAPrivatizablePtrImpl::identifyPrivatizableType(...) | |||
6771 | Optional<Type *> identifyPrivatizableType(Attributor &A) override { | |||
6772 | Value *Obj = getUnderlyingObject(&getAssociatedValue()); | |||
6773 | if (!Obj) { | |||
6774 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] No underlying object found!\n")do { } while (false); | |||
6775 | return nullptr; | |||
6776 | } | |||
6777 | ||||
6778 | if (auto *AI = dyn_cast<AllocaInst>(Obj)) | |||
6779 | if (auto *CI = dyn_cast<ConstantInt>(AI->getArraySize())) | |||
6780 | if (CI->isOne()) | |||
6781 | return Obj->getType()->getPointerElementType(); | |||
6782 | if (auto *Arg = dyn_cast<Argument>(Obj)) { | |||
6783 | auto &PrivArgAA = A.getAAFor<AAPrivatizablePtr>( | |||
6784 | *this, IRPosition::argument(*Arg), DepClassTy::REQUIRED); | |||
6785 | if (PrivArgAA.isAssumedPrivatizablePtr()) | |||
6786 | return Obj->getType()->getPointerElementType(); | |||
6787 | } | |||
6788 | ||||
6789 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] Underlying object neither valid "do { } while (false) | |||
6790 | "alloca nor privatizable argument: "do { } while (false) | |||
6791 | << *Obj << "!\n")do { } while (false); | |||
6792 | return nullptr; | |||
6793 | } | |||
6794 | ||||
6795 | /// See AbstractAttribute::trackStatistics() | |||
6796 | void trackStatistics() const override { | |||
6797 | STATS_DECLTRACK_FLOATING_ATTR(privatizable_ptr){ static llvm::Statistic NumIRFloating_privatizable_ptr = {"attributor" , "NumIRFloating_privatizable_ptr", ("Number of floating values known to be '" "privatizable_ptr" "'")};; ++(NumIRFloating_privatizable_ptr ); }; | |||
6798 | } | |||
6799 | }; | |||
6800 | ||||
6801 | struct AAPrivatizablePtrCallSiteArgument final | |||
6802 | : public AAPrivatizablePtrFloating { | |||
6803 | AAPrivatizablePtrCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
6804 | : AAPrivatizablePtrFloating(IRP, A) {} | |||
6805 | ||||
6806 | /// See AbstractAttribute::initialize(...). | |||
6807 | void initialize(Attributor &A) override { | |||
6808 | if (getIRPosition().hasAttr(Attribute::ByVal)) | |||
6809 | indicateOptimisticFixpoint(); | |||
6810 | } | |||
6811 | ||||
6812 | /// See AbstractAttribute::updateImpl(...). | |||
6813 | ChangeStatus updateImpl(Attributor &A) override { | |||
6814 | PrivatizableType = identifyPrivatizableType(A); | |||
6815 | if (!PrivatizableType.hasValue()) | |||
6816 | return ChangeStatus::UNCHANGED; | |||
6817 | if (!PrivatizableType.getValue()) | |||
6818 | return indicatePessimisticFixpoint(); | |||
6819 | ||||
6820 | const IRPosition &IRP = getIRPosition(); | |||
6821 | auto &NoCaptureAA = | |||
6822 | A.getAAFor<AANoCapture>(*this, IRP, DepClassTy::REQUIRED); | |||
6823 | if (!NoCaptureAA.isAssumedNoCapture()) { | |||
6824 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] pointer might be captured!\n")do { } while (false); | |||
6825 | return indicatePessimisticFixpoint(); | |||
6826 | } | |||
6827 | ||||
6828 | auto &NoAliasAA = A.getAAFor<AANoAlias>(*this, IRP, DepClassTy::REQUIRED); | |||
6829 | if (!NoAliasAA.isAssumedNoAlias()) { | |||
6830 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] pointer might alias!\n")do { } while (false); | |||
6831 | return indicatePessimisticFixpoint(); | |||
6832 | } | |||
6833 | ||||
6834 | const auto &MemBehaviorAA = | |||
6835 | A.getAAFor<AAMemoryBehavior>(*this, IRP, DepClassTy::REQUIRED); | |||
6836 | if (!MemBehaviorAA.isAssumedReadOnly()) { | |||
6837 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] pointer is written!\n")do { } while (false); | |||
6838 | return indicatePessimisticFixpoint(); | |||
6839 | } | |||
6840 | ||||
6841 | return ChangeStatus::UNCHANGED; | |||
6842 | } | |||
6843 | ||||
6844 | /// See AbstractAttribute::trackStatistics() | |||
6845 | void trackStatistics() const override { | |||
6846 | STATS_DECLTRACK_CSARG_ATTR(privatizable_ptr){ static llvm::Statistic NumIRCSArguments_privatizable_ptr = { "attributor", "NumIRCSArguments_privatizable_ptr", ("Number of " "call site arguments" " marked '" "privatizable_ptr" "'")};; ++(NumIRCSArguments_privatizable_ptr); }; | |||
6847 | } | |||
6848 | }; | |||
6849 | ||||
6850 | struct AAPrivatizablePtrCallSiteReturned final | |||
6851 | : public AAPrivatizablePtrFloating { | |||
6852 | AAPrivatizablePtrCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
6853 | : AAPrivatizablePtrFloating(IRP, A) {} | |||
6854 | ||||
6855 | /// See AbstractAttribute::initialize(...). | |||
6856 | void initialize(Attributor &A) override { | |||
6857 | // TODO: We can privatize more than arguments. | |||
6858 | indicatePessimisticFixpoint(); | |||
6859 | } | |||
6860 | ||||
6861 | /// See AbstractAttribute::trackStatistics() | |||
6862 | void trackStatistics() const override { | |||
6863 | STATS_DECLTRACK_CSRET_ATTR(privatizable_ptr){ static llvm::Statistic NumIRCSReturn_privatizable_ptr = {"attributor" , "NumIRCSReturn_privatizable_ptr", ("Number of " "call site returns" " marked '" "privatizable_ptr" "'")};; ++(NumIRCSReturn_privatizable_ptr ); }; | |||
6864 | } | |||
6865 | }; | |||
6866 | ||||
6867 | struct AAPrivatizablePtrReturned final : public AAPrivatizablePtrFloating { | |||
6868 | AAPrivatizablePtrReturned(const IRPosition &IRP, Attributor &A) | |||
6869 | : AAPrivatizablePtrFloating(IRP, A) {} | |||
6870 | ||||
6871 | /// See AbstractAttribute::initialize(...). | |||
6872 | void initialize(Attributor &A) override { | |||
6873 | // TODO: We can privatize more than arguments. | |||
6874 | indicatePessimisticFixpoint(); | |||
6875 | } | |||
6876 | ||||
6877 | /// See AbstractAttribute::trackStatistics() | |||
6878 | void trackStatistics() const override { | |||
6879 | STATS_DECLTRACK_FNRET_ATTR(privatizable_ptr){ static llvm::Statistic NumIRFunctionReturn_privatizable_ptr = {"attributor", "NumIRFunctionReturn_privatizable_ptr", ("Number of " "function returns" " marked '" "privatizable_ptr" "'")};; ++ (NumIRFunctionReturn_privatizable_ptr); }; | |||
6880 | } | |||
6881 | }; | |||
6882 | ||||
6883 | /// -------------------- Memory Behavior Attributes ---------------------------- | |||
6884 | /// Includes read-none, read-only, and write-only. | |||
6885 | /// ---------------------------------------------------------------------------- | |||
6886 | struct AAMemoryBehaviorImpl : public AAMemoryBehavior { | |||
6887 | AAMemoryBehaviorImpl(const IRPosition &IRP, Attributor &A) | |||
6888 | : AAMemoryBehavior(IRP, A) {} | |||
6889 | ||||
6890 | /// See AbstractAttribute::initialize(...). | |||
6891 | void initialize(Attributor &A) override { | |||
6892 | intersectAssumedBits(BEST_STATE); | |||
6893 | getKnownStateFromValue(getIRPosition(), getState()); | |||
6894 | AAMemoryBehavior::initialize(A); | |||
6895 | } | |||
6896 | ||||
6897 | /// Return the memory behavior information encoded in the IR for \p IRP. | |||
6898 | static void getKnownStateFromValue(const IRPosition &IRP, | |||
6899 | BitIntegerState &State, | |||
6900 | bool IgnoreSubsumingPositions = false) { | |||
6901 | SmallVector<Attribute, 2> Attrs; | |||
6902 | IRP.getAttrs(AttrKinds, Attrs, IgnoreSubsumingPositions); | |||
6903 | for (const Attribute &Attr : Attrs) { | |||
6904 | switch (Attr.getKindAsEnum()) { | |||
6905 | case Attribute::ReadNone: | |||
6906 | State.addKnownBits(NO_ACCESSES); | |||
6907 | break; | |||
6908 | case Attribute::ReadOnly: | |||
6909 | State.addKnownBits(NO_WRITES); | |||
6910 | break; | |||
6911 | case Attribute::WriteOnly: | |||
6912 | State.addKnownBits(NO_READS); | |||
6913 | break; | |||
6914 | default: | |||
6915 | llvm_unreachable("Unexpected attribute!")__builtin_unreachable(); | |||
6916 | } | |||
6917 | } | |||
6918 | ||||
6919 | if (auto *I = dyn_cast<Instruction>(&IRP.getAnchorValue())) { | |||
6920 | if (!I->mayReadFromMemory()) | |||
6921 | State.addKnownBits(NO_READS); | |||
6922 | if (!I->mayWriteToMemory()) | |||
6923 | State.addKnownBits(NO_WRITES); | |||
6924 | } | |||
6925 | } | |||
6926 | ||||
6927 | /// See AbstractAttribute::getDeducedAttributes(...). | |||
6928 | void getDeducedAttributes(LLVMContext &Ctx, | |||
6929 | SmallVectorImpl<Attribute> &Attrs) const override { | |||
6930 | assert(Attrs.size() == 0)((void)0); | |||
6931 | if (isAssumedReadNone()) | |||
6932 | Attrs.push_back(Attribute::get(Ctx, Attribute::ReadNone)); | |||
6933 | else if (isAssumedReadOnly()) | |||
6934 | Attrs.push_back(Attribute::get(Ctx, Attribute::ReadOnly)); | |||
6935 | else if (isAssumedWriteOnly()) | |||
6936 | Attrs.push_back(Attribute::get(Ctx, Attribute::WriteOnly)); | |||
6937 | assert(Attrs.size() <= 1)((void)0); | |||
6938 | } | |||
6939 | ||||
6940 | /// See AbstractAttribute::manifest(...). | |||
6941 | ChangeStatus manifest(Attributor &A) override { | |||
6942 | if (hasAttr(Attribute::ReadNone, /* IgnoreSubsumingPositions */ true)) | |||
6943 | return ChangeStatus::UNCHANGED; | |||
6944 | ||||
6945 | const IRPosition &IRP = getIRPosition(); | |||
6946 | ||||
6947 | // Check if we would improve the existing attributes first. | |||
6948 | SmallVector<Attribute, 4> DeducedAttrs; | |||
6949 | getDeducedAttributes(IRP.getAnchorValue().getContext(), DeducedAttrs); | |||
6950 | if (llvm::all_of(DeducedAttrs, [&](const Attribute &Attr) { | |||
6951 | return IRP.hasAttr(Attr.getKindAsEnum(), | |||
6952 | /* IgnoreSubsumingPositions */ true); | |||
6953 | })) | |||
6954 | return ChangeStatus::UNCHANGED; | |||
6955 | ||||
6956 | // Clear existing attributes. | |||
6957 | IRP.removeAttrs(AttrKinds); | |||
6958 | ||||
6959 | // Use the generic manifest method. | |||
6960 | return IRAttribute::manifest(A); | |||
6961 | } | |||
6962 | ||||
6963 | /// See AbstractState::getAsStr(). | |||
6964 | const std::string getAsStr() const override { | |||
6965 | if (isAssumedReadNone()) | |||
6966 | return "readnone"; | |||
6967 | if (isAssumedReadOnly()) | |||
6968 | return "readonly"; | |||
6969 | if (isAssumedWriteOnly()) | |||
6970 | return "writeonly"; | |||
6971 | return "may-read/write"; | |||
6972 | } | |||
6973 | ||||
6974 | /// The set of IR attributes AAMemoryBehavior deals with. | |||
6975 | static const Attribute::AttrKind AttrKinds[3]; | |||
6976 | }; | |||
6977 | ||||
6978 | const Attribute::AttrKind AAMemoryBehaviorImpl::AttrKinds[] = { | |||
6979 | Attribute::ReadNone, Attribute::ReadOnly, Attribute::WriteOnly}; | |||
6980 | ||||
6981 | /// Memory behavior attribute for a floating value. | |||
6982 | struct AAMemoryBehaviorFloating : AAMemoryBehaviorImpl { | |||
6983 | AAMemoryBehaviorFloating(const IRPosition &IRP, Attributor &A) | |||
6984 | : AAMemoryBehaviorImpl(IRP, A) {} | |||
6985 | ||||
6986 | /// See AbstractAttribute::updateImpl(...). | |||
6987 | ChangeStatus updateImpl(Attributor &A) override; | |||
6988 | ||||
6989 | /// See AbstractAttribute::trackStatistics() | |||
6990 | void trackStatistics() const override { | |||
6991 | if (isAssumedReadNone()) | |||
6992 | STATS_DECLTRACK_FLOATING_ATTR(readnone){ static llvm::Statistic NumIRFloating_readnone = {"attributor" , "NumIRFloating_readnone", ("Number of floating values known to be '" "readnone" "'")};; ++(NumIRFloating_readnone); } | |||
6993 | else if (isAssumedReadOnly()) | |||
6994 | STATS_DECLTRACK_FLOATING_ATTR(readonly){ static llvm::Statistic NumIRFloating_readonly = {"attributor" , "NumIRFloating_readonly", ("Number of floating values known to be '" "readonly" "'")};; ++(NumIRFloating_readonly); } | |||
6995 | else if (isAssumedWriteOnly()) | |||
6996 | STATS_DECLTRACK_FLOATING_ATTR(writeonly){ static llvm::Statistic NumIRFloating_writeonly = {"attributor" , "NumIRFloating_writeonly", ("Number of floating values known to be '" "writeonly" "'")};; ++(NumIRFloating_writeonly); } | |||
6997 | } | |||
6998 | ||||
6999 | private: | |||
7000 | /// Return true if users of \p UserI might access the underlying | |||
7001 | /// variable/location described by \p U and should therefore be analyzed. | |||
7002 | bool followUsersOfUseIn(Attributor &A, const Use &U, | |||
7003 | const Instruction *UserI); | |||
7004 | ||||
7005 | /// Update the state according to the effect of use \p U in \p UserI. | |||
7006 | void analyzeUseIn(Attributor &A, const Use &U, const Instruction *UserI); | |||
7007 | }; | |||
7008 | ||||
7009 | /// Memory behavior attribute for function argument. | |||
7010 | struct AAMemoryBehaviorArgument : AAMemoryBehaviorFloating { | |||
7011 | AAMemoryBehaviorArgument(const IRPosition &IRP, Attributor &A) | |||
7012 | : AAMemoryBehaviorFloating(IRP, A) {} | |||
7013 | ||||
7014 | /// See AbstractAttribute::initialize(...). | |||
7015 | void initialize(Attributor &A) override { | |||
7016 | intersectAssumedBits(BEST_STATE); | |||
7017 | const IRPosition &IRP = getIRPosition(); | |||
7018 | // TODO: Make IgnoreSubsumingPositions a property of an IRAttribute so we | |||
7019 | // can query it when we use has/getAttr. That would allow us to reuse the | |||
7020 | // initialize of the base class here. | |||
7021 | bool HasByVal = | |||
7022 | IRP.hasAttr({Attribute::ByVal}, /* IgnoreSubsumingPositions */ true); | |||
7023 | getKnownStateFromValue(IRP, getState(), | |||
7024 | /* IgnoreSubsumingPositions */ HasByVal); | |||
7025 | ||||
7026 | // Initialize the use vector with all direct uses of the associated value. | |||
7027 | Argument *Arg = getAssociatedArgument(); | |||
7028 | if (!Arg || !A.isFunctionIPOAmendable(*(Arg->getParent()))) | |||
7029 | indicatePessimisticFixpoint(); | |||
7030 | } | |||
7031 | ||||
7032 | ChangeStatus manifest(Attributor &A) override { | |||
7033 | // TODO: Pointer arguments are not supported on vectors of pointers yet. | |||
7034 | if (!getAssociatedValue().getType()->isPointerTy()) | |||
7035 | return ChangeStatus::UNCHANGED; | |||
7036 | ||||
7037 | // TODO: From readattrs.ll: "inalloca parameters are always | |||
7038 | // considered written" | |||
7039 | if (hasAttr({Attribute::InAlloca, Attribute::Preallocated})) { | |||
7040 | removeKnownBits(NO_WRITES); | |||
7041 | removeAssumedBits(NO_WRITES); | |||
7042 | } | |||
7043 | return AAMemoryBehaviorFloating::manifest(A); | |||
7044 | } | |||
7045 | ||||
7046 | /// See AbstractAttribute::trackStatistics() | |||
7047 | void trackStatistics() const override { | |||
7048 | if (isAssumedReadNone()) | |||
7049 | STATS_DECLTRACK_ARG_ATTR(readnone){ static llvm::Statistic NumIRArguments_readnone = {"attributor" , "NumIRArguments_readnone", ("Number of " "arguments" " marked '" "readnone" "'")};; ++(NumIRArguments_readnone); } | |||
7050 | else if (isAssumedReadOnly()) | |||
7051 | STATS_DECLTRACK_ARG_ATTR(readonly){ static llvm::Statistic NumIRArguments_readonly = {"attributor" , "NumIRArguments_readonly", ("Number of " "arguments" " marked '" "readonly" "'")};; ++(NumIRArguments_readonly); } | |||
7052 | else if (isAssumedWriteOnly()) | |||
7053 | STATS_DECLTRACK_ARG_ATTR(writeonly){ static llvm::Statistic NumIRArguments_writeonly = {"attributor" , "NumIRArguments_writeonly", ("Number of " "arguments" " marked '" "writeonly" "'")};; ++(NumIRArguments_writeonly); } | |||
7054 | } | |||
7055 | }; | |||
7056 | ||||
7057 | struct AAMemoryBehaviorCallSiteArgument final : AAMemoryBehaviorArgument { | |||
7058 | AAMemoryBehaviorCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
7059 | : AAMemoryBehaviorArgument(IRP, A) {} | |||
7060 | ||||
7061 | /// See AbstractAttribute::initialize(...). | |||
7062 | void initialize(Attributor &A) override { | |||
7063 | // If we don't have an associated attribute this is either a variadic call | |||
7064 | // or an indirect call, either way, nothing to do here. | |||
7065 | Argument *Arg = getAssociatedArgument(); | |||
7066 | if (!Arg) { | |||
7067 | indicatePessimisticFixpoint(); | |||
7068 | return; | |||
7069 | } | |||
7070 | if (Arg->hasByValAttr()) { | |||
7071 | addKnownBits(NO_WRITES); | |||
7072 | removeKnownBits(NO_READS); | |||
7073 | removeAssumedBits(NO_READS); | |||
7074 | } | |||
7075 | AAMemoryBehaviorArgument::initialize(A); | |||
7076 | if (getAssociatedFunction()->isDeclaration()) | |||
7077 | indicatePessimisticFixpoint(); | |||
7078 | } | |||
7079 | ||||
7080 | /// See AbstractAttribute::updateImpl(...). | |||
7081 | ChangeStatus updateImpl(Attributor &A) override { | |||
7082 | // TODO: Once we have call site specific value information we can provide | |||
7083 | // call site specific liveness liveness information and then it makes | |||
7084 | // sense to specialize attributes for call sites arguments instead of | |||
7085 | // redirecting requests to the callee argument. | |||
7086 | Argument *Arg = getAssociatedArgument(); | |||
7087 | const IRPosition &ArgPos = IRPosition::argument(*Arg); | |||
7088 | auto &ArgAA = | |||
7089 | A.getAAFor<AAMemoryBehavior>(*this, ArgPos, DepClassTy::REQUIRED); | |||
7090 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); | |||
7091 | } | |||
7092 | ||||
7093 | /// See AbstractAttribute::trackStatistics() | |||
7094 | void trackStatistics() const override { | |||
7095 | if (isAssumedReadNone()) | |||
7096 | STATS_DECLTRACK_CSARG_ATTR(readnone){ static llvm::Statistic NumIRCSArguments_readnone = {"attributor" , "NumIRCSArguments_readnone", ("Number of " "call site arguments" " marked '" "readnone" "'")};; ++(NumIRCSArguments_readnone) ; } | |||
7097 | else if (isAssumedReadOnly()) | |||
7098 | STATS_DECLTRACK_CSARG_ATTR(readonly){ static llvm::Statistic NumIRCSArguments_readonly = {"attributor" , "NumIRCSArguments_readonly", ("Number of " "call site arguments" " marked '" "readonly" "'")};; ++(NumIRCSArguments_readonly) ; } | |||
7099 | else if (isAssumedWriteOnly()) | |||
7100 | STATS_DECLTRACK_CSARG_ATTR(writeonly){ static llvm::Statistic NumIRCSArguments_writeonly = {"attributor" , "NumIRCSArguments_writeonly", ("Number of " "call site arguments" " marked '" "writeonly" "'")};; ++(NumIRCSArguments_writeonly ); } | |||
7101 | } | |||
7102 | }; | |||
7103 | ||||
7104 | /// Memory behavior attribute for a call site return position. | |||
7105 | struct AAMemoryBehaviorCallSiteReturned final : AAMemoryBehaviorFloating { | |||
7106 | AAMemoryBehaviorCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
7107 | : AAMemoryBehaviorFloating(IRP, A) {} | |||
7108 | ||||
7109 | /// See AbstractAttribute::initialize(...). | |||
7110 | void initialize(Attributor &A) override { | |||
7111 | AAMemoryBehaviorImpl::initialize(A); | |||
7112 | Function *F = getAssociatedFunction(); | |||
7113 | if (!F || F->isDeclaration()) | |||
7114 | indicatePessimisticFixpoint(); | |||
7115 | } | |||
7116 | ||||
7117 | /// See AbstractAttribute::manifest(...). | |||
7118 | ChangeStatus manifest(Attributor &A) override { | |||
7119 | // We do not annotate returned values. | |||
7120 | return ChangeStatus::UNCHANGED; | |||
7121 | } | |||
7122 | ||||
7123 | /// See AbstractAttribute::trackStatistics() | |||
7124 | void trackStatistics() const override {} | |||
7125 | }; | |||
7126 | ||||
7127 | /// An AA to represent the memory behavior function attributes. | |||
7128 | struct AAMemoryBehaviorFunction final : public AAMemoryBehaviorImpl { | |||
7129 | AAMemoryBehaviorFunction(const IRPosition &IRP, Attributor &A) | |||
7130 | : AAMemoryBehaviorImpl(IRP, A) {} | |||
7131 | ||||
7132 | /// See AbstractAttribute::updateImpl(Attributor &A). | |||
7133 | virtual ChangeStatus updateImpl(Attributor &A) override; | |||
7134 | ||||
7135 | /// See AbstractAttribute::manifest(...). | |||
7136 | ChangeStatus manifest(Attributor &A) override { | |||
7137 | Function &F = cast<Function>(getAnchorValue()); | |||
7138 | if (isAssumedReadNone()) { | |||
7139 | F.removeFnAttr(Attribute::ArgMemOnly); | |||
7140 | F.removeFnAttr(Attribute::InaccessibleMemOnly); | |||
7141 | F.removeFnAttr(Attribute::InaccessibleMemOrArgMemOnly); | |||
7142 | } | |||
7143 | return AAMemoryBehaviorImpl::manifest(A); | |||
7144 | } | |||
7145 | ||||
7146 | /// See AbstractAttribute::trackStatistics() | |||
7147 | void trackStatistics() const override { | |||
7148 | if (isAssumedReadNone()) | |||
7149 | STATS_DECLTRACK_FN_ATTR(readnone){ static llvm::Statistic NumIRFunction_readnone = {"attributor" , "NumIRFunction_readnone", ("Number of " "functions" " marked '" "readnone" "'")};; ++(NumIRFunction_readnone); } | |||
7150 | else if (isAssumedReadOnly()) | |||
7151 | STATS_DECLTRACK_FN_ATTR(readonly){ static llvm::Statistic NumIRFunction_readonly = {"attributor" , "NumIRFunction_readonly", ("Number of " "functions" " marked '" "readonly" "'")};; ++(NumIRFunction_readonly); } | |||
7152 | else if (isAssumedWriteOnly()) | |||
7153 | STATS_DECLTRACK_FN_ATTR(writeonly){ static llvm::Statistic NumIRFunction_writeonly = {"attributor" , "NumIRFunction_writeonly", ("Number of " "functions" " marked '" "writeonly" "'")};; ++(NumIRFunction_writeonly); } | |||
7154 | } | |||
7155 | }; | |||
7156 | ||||
7157 | /// AAMemoryBehavior attribute for call sites. | |||
7158 | struct AAMemoryBehaviorCallSite final : AAMemoryBehaviorImpl { | |||
7159 | AAMemoryBehaviorCallSite(const IRPosition &IRP, Attributor &A) | |||
7160 | : AAMemoryBehaviorImpl(IRP, A) {} | |||
7161 | ||||
7162 | /// See AbstractAttribute::initialize(...). | |||
7163 | void initialize(Attributor &A) override { | |||
7164 | AAMemoryBehaviorImpl::initialize(A); | |||
7165 | Function *F = getAssociatedFunction(); | |||
7166 | if (!F || F->isDeclaration()) | |||
7167 | indicatePessimisticFixpoint(); | |||
7168 | } | |||
7169 | ||||
7170 | /// See AbstractAttribute::updateImpl(...). | |||
7171 | ChangeStatus updateImpl(Attributor &A) override { | |||
7172 | // TODO: Once we have call site specific value information we can provide | |||
7173 | // call site specific liveness liveness information and then it makes | |||
7174 | // sense to specialize attributes for call sites arguments instead of | |||
7175 | // redirecting requests to the callee argument. | |||
7176 | Function *F = getAssociatedFunction(); | |||
7177 | const IRPosition &FnPos = IRPosition::function(*F); | |||
7178 | auto &FnAA = | |||
7179 | A.getAAFor<AAMemoryBehavior>(*this, FnPos, DepClassTy::REQUIRED); | |||
7180 | return clampStateAndIndicateChange(getState(), FnAA.getState()); | |||
7181 | } | |||
7182 | ||||
7183 | /// See AbstractAttribute::trackStatistics() | |||
7184 | void trackStatistics() const override { | |||
7185 | if (isAssumedReadNone()) | |||
7186 | STATS_DECLTRACK_CS_ATTR(readnone){ static llvm::Statistic NumIRCS_readnone = {"attributor", "NumIRCS_readnone" , ("Number of " "call site" " marked '" "readnone" "'")};; ++ (NumIRCS_readnone); } | |||
7187 | else if (isAssumedReadOnly()) | |||
7188 | STATS_DECLTRACK_CS_ATTR(readonly){ static llvm::Statistic NumIRCS_readonly = {"attributor", "NumIRCS_readonly" , ("Number of " "call site" " marked '" "readonly" "'")};; ++ (NumIRCS_readonly); } | |||
7189 | else if (isAssumedWriteOnly()) | |||
7190 | STATS_DECLTRACK_CS_ATTR(writeonly){ static llvm::Statistic NumIRCS_writeonly = {"attributor", "NumIRCS_writeonly" , ("Number of " "call site" " marked '" "writeonly" "'")};; ++ (NumIRCS_writeonly); } | |||
7191 | } | |||
7192 | }; | |||
7193 | ||||
7194 | ChangeStatus AAMemoryBehaviorFunction::updateImpl(Attributor &A) { | |||
7195 | ||||
7196 | // The current assumed state used to determine a change. | |||
7197 | auto AssumedState = getAssumed(); | |||
7198 | ||||
7199 | auto CheckRWInst = [&](Instruction &I) { | |||
7200 | // If the instruction has an own memory behavior state, use it to restrict | |||
7201 | // the local state. No further analysis is required as the other memory | |||
7202 | // state is as optimistic as it gets. | |||
7203 | if (const auto *CB = dyn_cast<CallBase>(&I)) { | |||
7204 | const auto &MemBehaviorAA = A.getAAFor<AAMemoryBehavior>( | |||
7205 | *this, IRPosition::callsite_function(*CB), DepClassTy::REQUIRED); | |||
7206 | intersectAssumedBits(MemBehaviorAA.getAssumed()); | |||
7207 | return !isAtFixpoint(); | |||
7208 | } | |||
7209 | ||||
7210 | // Remove access kind modifiers if necessary. | |||
7211 | if (I.mayReadFromMemory()) | |||
7212 | removeAssumedBits(NO_READS); | |||
7213 | if (I.mayWriteToMemory()) | |||
7214 | removeAssumedBits(NO_WRITES); | |||
7215 | return !isAtFixpoint(); | |||
7216 | }; | |||
7217 | ||||
7218 | bool UsedAssumedInformation = false; | |||
7219 | if (!A.checkForAllReadWriteInstructions(CheckRWInst, *this, | |||
7220 | UsedAssumedInformation)) | |||
7221 | return indicatePessimisticFixpoint(); | |||
7222 | ||||
7223 | return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED | |||
7224 | : ChangeStatus::UNCHANGED; | |||
7225 | } | |||
7226 | ||||
7227 | ChangeStatus AAMemoryBehaviorFloating::updateImpl(Attributor &A) { | |||
7228 | ||||
7229 | const IRPosition &IRP = getIRPosition(); | |||
7230 | const IRPosition &FnPos = IRPosition::function_scope(IRP); | |||
7231 | AAMemoryBehavior::StateType &S = getState(); | |||
7232 | ||||
7233 | // First, check the function scope. We take the known information and we avoid | |||
7234 | // work if the assumed information implies the current assumed information for | |||
7235 | // this attribute. This is a valid for all but byval arguments. | |||
7236 | Argument *Arg = IRP.getAssociatedArgument(); | |||
7237 | AAMemoryBehavior::base_t FnMemAssumedState = | |||
7238 | AAMemoryBehavior::StateType::getWorstState(); | |||
7239 | if (!Arg || !Arg->hasByValAttr()) { | |||
7240 | const auto &FnMemAA = | |||
7241 | A.getAAFor<AAMemoryBehavior>(*this, FnPos, DepClassTy::OPTIONAL); | |||
7242 | FnMemAssumedState = FnMemAA.getAssumed(); | |||
7243 | S.addKnownBits(FnMemAA.getKnown()); | |||
7244 | if ((S.getAssumed() & FnMemAA.getAssumed()) == S.getAssumed()) | |||
7245 | return ChangeStatus::UNCHANGED; | |||
7246 | } | |||
7247 | ||||
7248 | // The current assumed state used to determine a change. | |||
7249 | auto AssumedState = S.getAssumed(); | |||
7250 | ||||
7251 | // Make sure the value is not captured (except through "return"), if | |||
7252 | // it is, any information derived would be irrelevant anyway as we cannot | |||
7253 | // check the potential aliases introduced by the capture. However, no need | |||
7254 | // to fall back to anythign less optimistic than the function state. | |||
7255 | const auto &ArgNoCaptureAA = | |||
7256 | A.getAAFor<AANoCapture>(*this, IRP, DepClassTy::OPTIONAL); | |||
7257 | if (!ArgNoCaptureAA.isAssumedNoCaptureMaybeReturned()) { | |||
7258 | S.intersectAssumedBits(FnMemAssumedState); | |||
7259 | return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED | |||
7260 | : ChangeStatus::UNCHANGED; | |||
7261 | } | |||
7262 | ||||
7263 | // Visit and expand uses until all are analyzed or a fixpoint is reached. | |||
7264 | auto UsePred = [&](const Use &U, bool &Follow) -> bool { | |||
7265 | Instruction *UserI = cast<Instruction>(U.getUser()); | |||
7266 | LLVM_DEBUG(dbgs() << "[AAMemoryBehavior] Use: " << *U << " in " << *UserIdo { } while (false) | |||
7267 | << " \n")do { } while (false); | |||
7268 | ||||
7269 | // Droppable users, e.g., llvm::assume does not actually perform any action. | |||
7270 | if (UserI->isDroppable()) | |||
7271 | return true; | |||
7272 | ||||
7273 | // Check if the users of UserI should also be visited. | |||
7274 | Follow = followUsersOfUseIn(A, U, UserI); | |||
7275 | ||||
7276 | // If UserI might touch memory we analyze the use in detail. | |||
7277 | if (UserI->mayReadOrWriteMemory()) | |||
7278 | analyzeUseIn(A, U, UserI); | |||
7279 | ||||
7280 | return !isAtFixpoint(); | |||
7281 | }; | |||
7282 | ||||
7283 | if (!A.checkForAllUses(UsePred, *this, getAssociatedValue())) | |||
7284 | return indicatePessimisticFixpoint(); | |||
7285 | ||||
7286 | return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED | |||
7287 | : ChangeStatus::UNCHANGED; | |||
7288 | } | |||
7289 | ||||
7290 | bool AAMemoryBehaviorFloating::followUsersOfUseIn(Attributor &A, const Use &U, | |||
7291 | const Instruction *UserI) { | |||
7292 | // The loaded value is unrelated to the pointer argument, no need to | |||
7293 | // follow the users of the load. | |||
7294 | if (isa<LoadInst>(UserI)) | |||
7295 | return false; | |||
7296 | ||||
7297 | // By default we follow all uses assuming UserI might leak information on U, | |||
7298 | // we have special handling for call sites operands though. | |||
7299 | const auto *CB = dyn_cast<CallBase>(UserI); | |||
7300 | if (!CB || !CB->isArgOperand(&U)) | |||
7301 | return true; | |||
7302 | ||||
7303 | // If the use is a call argument known not to be captured, the users of | |||
7304 | // the call do not need to be visited because they have to be unrelated to | |||
7305 | // the input. Note that this check is not trivial even though we disallow | |||
7306 | // general capturing of the underlying argument. The reason is that the | |||
7307 | // call might the argument "through return", which we allow and for which we | |||
7308 | // need to check call users. | |||
7309 | if (U.get()->getType()->isPointerTy()) { | |||
7310 | unsigned ArgNo = CB->getArgOperandNo(&U); | |||
7311 | const auto &ArgNoCaptureAA = A.getAAFor<AANoCapture>( | |||
7312 | *this, IRPosition::callsite_argument(*CB, ArgNo), DepClassTy::OPTIONAL); | |||
7313 | return !ArgNoCaptureAA.isAssumedNoCapture(); | |||
7314 | } | |||
7315 | ||||
7316 | return true; | |||
7317 | } | |||
7318 | ||||
7319 | void AAMemoryBehaviorFloating::analyzeUseIn(Attributor &A, const Use &U, | |||
7320 | const Instruction *UserI) { | |||
7321 | assert(UserI->mayReadOrWriteMemory())((void)0); | |||
7322 | ||||
7323 | switch (UserI->getOpcode()) { | |||
7324 | default: | |||
7325 | // TODO: Handle all atomics and other side-effect operations we know of. | |||
7326 | break; | |||
7327 | case Instruction::Load: | |||
7328 | // Loads cause the NO_READS property to disappear. | |||
7329 | removeAssumedBits(NO_READS); | |||
7330 | return; | |||
7331 | ||||
7332 | case Instruction::Store: | |||
7333 | // Stores cause the NO_WRITES property to disappear if the use is the | |||
7334 | // pointer operand. Note that we do assume that capturing was taken care of | |||
7335 | // somewhere else. | |||
7336 | if (cast<StoreInst>(UserI)->getPointerOperand() == U.get()) | |||
7337 | removeAssumedBits(NO_WRITES); | |||
7338 | return; | |||
7339 | ||||
7340 | case Instruction::Call: | |||
7341 | case Instruction::CallBr: | |||
7342 | case Instruction::Invoke: { | |||
7343 | // For call sites we look at the argument memory behavior attribute (this | |||
7344 | // could be recursive!) in order to restrict our own state. | |||
7345 | const auto *CB = cast<CallBase>(UserI); | |||
7346 | ||||
7347 | // Give up on operand bundles. | |||
7348 | if (CB->isBundleOperand(&U)) { | |||
7349 | indicatePessimisticFixpoint(); | |||
7350 | return; | |||
7351 | } | |||
7352 | ||||
7353 | // Calling a function does read the function pointer, maybe write it if the | |||
7354 | // function is self-modifying. | |||
7355 | if (CB->isCallee(&U)) { | |||
7356 | removeAssumedBits(NO_READS); | |||
7357 | break; | |||
7358 | } | |||
7359 | ||||
7360 | // Adjust the possible access behavior based on the information on the | |||
7361 | // argument. | |||
7362 | IRPosition Pos; | |||
7363 | if (U.get()->getType()->isPointerTy()) | |||
7364 | Pos = IRPosition::callsite_argument(*CB, CB->getArgOperandNo(&U)); | |||
7365 | else | |||
7366 | Pos = IRPosition::callsite_function(*CB); | |||
7367 | const auto &MemBehaviorAA = | |||
7368 | A.getAAFor<AAMemoryBehavior>(*this, Pos, DepClassTy::OPTIONAL); | |||
7369 | // "assumed" has at most the same bits as the MemBehaviorAA assumed | |||
7370 | // and at least "known". | |||
7371 | intersectAssumedBits(MemBehaviorAA.getAssumed()); | |||
7372 | return; | |||
7373 | } | |||
7374 | }; | |||
7375 | ||||
7376 | // Generally, look at the "may-properties" and adjust the assumed state if we | |||
7377 | // did not trigger special handling before. | |||
7378 | if (UserI->mayReadFromMemory()) | |||
7379 | removeAssumedBits(NO_READS); | |||
7380 | if (UserI->mayWriteToMemory()) | |||
7381 | removeAssumedBits(NO_WRITES); | |||
7382 | } | |||
7383 | ||||
7384 | /// -------------------- Memory Locations Attributes --------------------------- | |||
7385 | /// Includes read-none, argmemonly, inaccessiblememonly, | |||
7386 | /// inaccessiblememorargmemonly | |||
7387 | /// ---------------------------------------------------------------------------- | |||
7388 | ||||
7389 | std::string AAMemoryLocation::getMemoryLocationsAsStr( | |||
7390 | AAMemoryLocation::MemoryLocationsKind MLK) { | |||
7391 | if (0 == (MLK & AAMemoryLocation::NO_LOCATIONS)) | |||
7392 | return "all memory"; | |||
7393 | if (MLK == AAMemoryLocation::NO_LOCATIONS) | |||
7394 | return "no memory"; | |||
7395 | std::string S = "memory:"; | |||
7396 | if (0 == (MLK & AAMemoryLocation::NO_LOCAL_MEM)) | |||
7397 | S += "stack,"; | |||
7398 | if (0 == (MLK & AAMemoryLocation::NO_CONST_MEM)) | |||
7399 | S += "constant,"; | |||
7400 | if (0 == (MLK & AAMemoryLocation::NO_GLOBAL_INTERNAL_MEM)) | |||
7401 | S += "internal global,"; | |||
7402 | if (0 == (MLK & AAMemoryLocation::NO_GLOBAL_EXTERNAL_MEM)) | |||
7403 | S += "external global,"; | |||
7404 | if (0 == (MLK & AAMemoryLocation::NO_ARGUMENT_MEM)) | |||
7405 | S += "argument,"; | |||
7406 | if (0 == (MLK & AAMemoryLocation::NO_INACCESSIBLE_MEM)) | |||
7407 | S += "inaccessible,"; | |||
7408 | if (0 == (MLK & AAMemoryLocation::NO_MALLOCED_MEM)) | |||
7409 | S += "malloced,"; | |||
7410 | if (0 == (MLK & AAMemoryLocation::NO_UNKOWN_MEM)) | |||
7411 | S += "unknown,"; | |||
7412 | S.pop_back(); | |||
7413 | return S; | |||
7414 | } | |||
7415 | ||||
7416 | namespace { | |||
7417 | struct AAMemoryLocationImpl : public AAMemoryLocation { | |||
7418 | ||||
7419 | AAMemoryLocationImpl(const IRPosition &IRP, Attributor &A) | |||
7420 | : AAMemoryLocation(IRP, A), Allocator(A.Allocator) { | |||
7421 | for (unsigned u = 0; u < llvm::CTLog2<VALID_STATE>(); ++u) | |||
7422 | AccessKind2Accesses[u] = nullptr; | |||
7423 | } | |||
7424 | ||||
7425 | ~AAMemoryLocationImpl() { | |||
7426 | // The AccessSets are allocated via a BumpPtrAllocator, we call | |||
7427 | // the destructor manually. | |||
7428 | for (unsigned u = 0; u < llvm::CTLog2<VALID_STATE>(); ++u) | |||
7429 | if (AccessKind2Accesses[u]) | |||
7430 | AccessKind2Accesses[u]->~AccessSet(); | |||
7431 | } | |||
7432 | ||||
7433 | /// See AbstractAttribute::initialize(...). | |||
7434 | void initialize(Attributor &A) override { | |||
7435 | intersectAssumedBits(BEST_STATE); | |||
7436 | getKnownStateFromValue(A, getIRPosition(), getState()); | |||
7437 | AAMemoryLocation::initialize(A); | |||
7438 | } | |||
7439 | ||||
7440 | /// Return the memory behavior information encoded in the IR for \p IRP. | |||
7441 | static void getKnownStateFromValue(Attributor &A, const IRPosition &IRP, | |||
7442 | BitIntegerState &State, | |||
7443 | bool IgnoreSubsumingPositions = false) { | |||
7444 | // For internal functions we ignore `argmemonly` and | |||
7445 | // `inaccessiblememorargmemonly` as we might break it via interprocedural | |||
7446 | // constant propagation. It is unclear if this is the best way but it is | |||
7447 | // unlikely this will cause real performance problems. If we are deriving | |||
7448 | // attributes for the anchor function we even remove the attribute in | |||
7449 | // addition to ignoring it. | |||
7450 | bool UseArgMemOnly = true; | |||
7451 | Function *AnchorFn = IRP.getAnchorScope(); | |||
7452 | if (AnchorFn && A.isRunOn(*AnchorFn)) | |||
7453 | UseArgMemOnly = !AnchorFn->hasLocalLinkage(); | |||
7454 | ||||
7455 | SmallVector<Attribute, 2> Attrs; | |||
7456 | IRP.getAttrs(AttrKinds, Attrs, IgnoreSubsumingPositions); | |||
7457 | for (const Attribute &Attr : Attrs) { | |||
7458 | switch (Attr.getKindAsEnum()) { | |||
7459 | case Attribute::ReadNone: | |||
7460 | State.addKnownBits(NO_LOCAL_MEM | NO_CONST_MEM); | |||
7461 | break; | |||
7462 | case Attribute::InaccessibleMemOnly: | |||
7463 | State.addKnownBits(inverseLocation(NO_INACCESSIBLE_MEM, true, true)); | |||
7464 | break; | |||
7465 | case Attribute::ArgMemOnly: | |||
7466 | if (UseArgMemOnly) | |||
7467 | State.addKnownBits(inverseLocation(NO_ARGUMENT_MEM, true, true)); | |||
7468 | else | |||
7469 | IRP.removeAttrs({Attribute::ArgMemOnly}); | |||
7470 | break; | |||
7471 | case Attribute::InaccessibleMemOrArgMemOnly: | |||
7472 | if (UseArgMemOnly) | |||
7473 | State.addKnownBits(inverseLocation( | |||
7474 | NO_INACCESSIBLE_MEM | NO_ARGUMENT_MEM, true, true)); | |||
7475 | else | |||
7476 | IRP.removeAttrs({Attribute::InaccessibleMemOrArgMemOnly}); | |||
7477 | break; | |||
7478 | default: | |||
7479 | llvm_unreachable("Unexpected attribute!")__builtin_unreachable(); | |||
7480 | } | |||
7481 | } | |||
7482 | } | |||
7483 | ||||
7484 | /// See AbstractAttribute::getDeducedAttributes(...). | |||
7485 | void getDeducedAttributes(LLVMContext &Ctx, | |||
7486 | SmallVectorImpl<Attribute> &Attrs) const override { | |||
7487 | assert(Attrs.size() == 0)((void)0); | |||
7488 | if (isAssumedReadNone()) { | |||
7489 | Attrs.push_back(Attribute::get(Ctx, Attribute::ReadNone)); | |||
7490 | } else if (getIRPosition().getPositionKind() == IRPosition::IRP_FUNCTION) { | |||
7491 | if (isAssumedInaccessibleMemOnly()) | |||
7492 | Attrs.push_back(Attribute::get(Ctx, Attribute::InaccessibleMemOnly)); | |||
7493 | else if (isAssumedArgMemOnly()) | |||
7494 | Attrs.push_back(Attribute::get(Ctx, Attribute::ArgMemOnly)); | |||
7495 | else if (isAssumedInaccessibleOrArgMemOnly()) | |||
7496 | Attrs.push_back( | |||
7497 | Attribute::get(Ctx, Attribute::InaccessibleMemOrArgMemOnly)); | |||
7498 | } | |||
7499 | assert(Attrs.size() <= 1)((void)0); | |||
7500 | } | |||
7501 | ||||
7502 | /// See AbstractAttribute::manifest(...). | |||
7503 | ChangeStatus manifest(Attributor &A) override { | |||
7504 | const IRPosition &IRP = getIRPosition(); | |||
7505 | ||||
7506 | // Check if we would improve the existing attributes first. | |||
7507 | SmallVector<Attribute, 4> DeducedAttrs; | |||
7508 | getDeducedAttributes(IRP.getAnchorValue().getContext(), DeducedAttrs); | |||
7509 | if (llvm::all_of(DeducedAttrs, [&](const Attribute &Attr) { | |||
7510 | return IRP.hasAttr(Attr.getKindAsEnum(), | |||
7511 | /* IgnoreSubsumingPositions */ true); | |||
7512 | })) | |||
7513 | return ChangeStatus::UNCHANGED; | |||
7514 | ||||
7515 | // Clear existing attributes. | |||
7516 | IRP.removeAttrs(AttrKinds); | |||
7517 | if (isAssumedReadNone()) | |||
7518 | IRP.removeAttrs(AAMemoryBehaviorImpl::AttrKinds); | |||
7519 | ||||
7520 | // Use the generic manifest method. | |||
7521 | return IRAttribute::manifest(A); | |||
7522 | } | |||
7523 | ||||
7524 | /// See AAMemoryLocation::checkForAllAccessesToMemoryKind(...). | |||
7525 | bool checkForAllAccessesToMemoryKind( | |||
7526 | function_ref<bool(const Instruction *, const Value *, AccessKind, | |||
7527 | MemoryLocationsKind)> | |||
7528 | Pred, | |||
7529 | MemoryLocationsKind RequestedMLK) const override { | |||
7530 | if (!isValidState()) | |||
7531 | return false; | |||
7532 | ||||
7533 | MemoryLocationsKind AssumedMLK = getAssumedNotAccessedLocation(); | |||
7534 | if (AssumedMLK == NO_LOCATIONS) | |||
7535 | return true; | |||
7536 | ||||
7537 | unsigned Idx = 0; | |||
7538 | for (MemoryLocationsKind CurMLK = 1; CurMLK < NO_LOCATIONS; | |||
7539 | CurMLK *= 2, ++Idx) { | |||
7540 | if (CurMLK & RequestedMLK) | |||
7541 | continue; | |||
7542 | ||||
7543 | if (const AccessSet *Accesses = AccessKind2Accesses[Idx]) | |||
7544 | for (const AccessInfo &AI : *Accesses) | |||
7545 | if (!Pred(AI.I, AI.Ptr, AI.Kind, CurMLK)) | |||
7546 | return false; | |||
7547 | } | |||
7548 | ||||
7549 | return true; | |||
7550 | } | |||
7551 | ||||
7552 | ChangeStatus indicatePessimisticFixpoint() override { | |||
7553 | // If we give up and indicate a pessimistic fixpoint this instruction will | |||
7554 | // become an access for all potential access kinds: | |||
7555 | // TODO: Add pointers for argmemonly and globals to improve the results of | |||
7556 | // checkForAllAccessesToMemoryKind. | |||
7557 | bool Changed = false; | |||
7558 | MemoryLocationsKind KnownMLK = getKnown(); | |||
7559 | Instruction *I = dyn_cast<Instruction>(&getAssociatedValue()); | |||
7560 | for (MemoryLocationsKind CurMLK = 1; CurMLK < NO_LOCATIONS; CurMLK *= 2) | |||
7561 | if (!(CurMLK & KnownMLK)) | |||
7562 | updateStateAndAccessesMap(getState(), CurMLK, I, nullptr, Changed, | |||
7563 | getAccessKindFromInst(I)); | |||
7564 | return AAMemoryLocation::indicatePessimisticFixpoint(); | |||
7565 | } | |||
7566 | ||||
7567 | protected: | |||
7568 | /// Helper struct to tie together an instruction that has a read or write | |||
7569 | /// effect with the pointer it accesses (if any). | |||
7570 | struct AccessInfo { | |||
7571 | ||||
7572 | /// The instruction that caused the access. | |||
7573 | const Instruction *I; | |||
7574 | ||||
7575 | /// The base pointer that is accessed, or null if unknown. | |||
7576 | const Value *Ptr; | |||
7577 | ||||
7578 | /// The kind of access (read/write/read+write). | |||
7579 | AccessKind Kind; | |||
7580 | ||||
7581 | bool operator==(const AccessInfo &RHS) const { | |||
7582 | return I == RHS.I && Ptr == RHS.Ptr && Kind == RHS.Kind; | |||
7583 | } | |||
7584 | bool operator()(const AccessInfo &LHS, const AccessInfo &RHS) const { | |||
7585 | if (LHS.I != RHS.I) | |||
7586 | return LHS.I < RHS.I; | |||
7587 | if (LHS.Ptr != RHS.Ptr) | |||
7588 | return LHS.Ptr < RHS.Ptr; | |||
7589 | if (LHS.Kind != RHS.Kind) | |||
7590 | return LHS.Kind < RHS.Kind; | |||
7591 | return false; | |||
7592 | } | |||
7593 | }; | |||
7594 | ||||
7595 | /// Mapping from *single* memory location kinds, e.g., LOCAL_MEM with the | |||
7596 | /// value of NO_LOCAL_MEM, to the accesses encountered for this memory kind. | |||
7597 | using AccessSet = SmallSet<AccessInfo, 2, AccessInfo>; | |||
7598 | AccessSet *AccessKind2Accesses[llvm::CTLog2<VALID_STATE>()]; | |||
7599 | ||||
7600 | /// Categorize the pointer arguments of CB that might access memory in | |||
7601 | /// AccessedLoc and update the state and access map accordingly. | |||
7602 | void | |||
7603 | categorizeArgumentPointerLocations(Attributor &A, CallBase &CB, | |||
7604 | AAMemoryLocation::StateType &AccessedLocs, | |||
7605 | bool &Changed); | |||
7606 | ||||
7607 | /// Return the kind(s) of location that may be accessed by \p V. | |||
7608 | AAMemoryLocation::MemoryLocationsKind | |||
7609 | categorizeAccessedLocations(Attributor &A, Instruction &I, bool &Changed); | |||
7610 | ||||
7611 | /// Return the access kind as determined by \p I. | |||
7612 | AccessKind getAccessKindFromInst(const Instruction *I) { | |||
7613 | AccessKind AK = READ_WRITE; | |||
7614 | if (I) { | |||
7615 | AK = I->mayReadFromMemory() ? READ : NONE; | |||
7616 | AK = AccessKind(AK | (I->mayWriteToMemory() ? WRITE : NONE)); | |||
7617 | } | |||
7618 | return AK; | |||
7619 | } | |||
7620 | ||||
7621 | /// Update the state \p State and the AccessKind2Accesses given that \p I is | |||
7622 | /// an access of kind \p AK to a \p MLK memory location with the access | |||
7623 | /// pointer \p Ptr. | |||
7624 | void updateStateAndAccessesMap(AAMemoryLocation::StateType &State, | |||
7625 | MemoryLocationsKind MLK, const Instruction *I, | |||
7626 | const Value *Ptr, bool &Changed, | |||
7627 | AccessKind AK = READ_WRITE) { | |||
7628 | ||||
7629 | assert(isPowerOf2_32(MLK) && "Expected a single location set!")((void)0); | |||
7630 | auto *&Accesses = AccessKind2Accesses[llvm::Log2_32(MLK)]; | |||
7631 | if (!Accesses) | |||
7632 | Accesses = new (Allocator) AccessSet(); | |||
7633 | Changed |= Accesses->insert(AccessInfo{I, Ptr, AK}).second; | |||
7634 | State.removeAssumedBits(MLK); | |||
7635 | } | |||
7636 | ||||
7637 | /// Determine the underlying locations kinds for \p Ptr, e.g., globals or | |||
7638 | /// arguments, and update the state and access map accordingly. | |||
7639 | void categorizePtrValue(Attributor &A, const Instruction &I, const Value &Ptr, | |||
7640 | AAMemoryLocation::StateType &State, bool &Changed); | |||
7641 | ||||
7642 | /// Used to allocate access sets. | |||
7643 | BumpPtrAllocator &Allocator; | |||
7644 | ||||
7645 | /// The set of IR attributes AAMemoryLocation deals with. | |||
7646 | static const Attribute::AttrKind AttrKinds[4]; | |||
7647 | }; | |||
7648 | ||||
7649 | const Attribute::AttrKind AAMemoryLocationImpl::AttrKinds[] = { | |||
7650 | Attribute::ReadNone, Attribute::InaccessibleMemOnly, Attribute::ArgMemOnly, | |||
7651 | Attribute::InaccessibleMemOrArgMemOnly}; | |||
7652 | ||||
7653 | void AAMemoryLocationImpl::categorizePtrValue( | |||
7654 | Attributor &A, const Instruction &I, const Value &Ptr, | |||
7655 | AAMemoryLocation::StateType &State, bool &Changed) { | |||
7656 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Categorize pointer locations for "do { } while (false) | |||
7657 | << Ptr << " ["do { } while (false) | |||
7658 | << getMemoryLocationsAsStr(State.getAssumed()) << "]\n")do { } while (false); | |||
7659 | ||||
7660 | SmallVector<Value *, 8> Objects; | |||
7661 | if (!AA::getAssumedUnderlyingObjects(A, Ptr, Objects, *this, &I)) { | |||
7662 | LLVM_DEBUG(do { } while (false) | |||
7663 | dbgs() << "[AAMemoryLocation] Pointer locations not categorized\n")do { } while (false); | |||
7664 | updateStateAndAccessesMap(State, NO_UNKOWN_MEM, &I, nullptr, Changed, | |||
7665 | getAccessKindFromInst(&I)); | |||
7666 | return; | |||
7667 | } | |||
7668 | ||||
7669 | for (Value *Obj : Objects) { | |||
7670 | // TODO: recognize the TBAA used for constant accesses. | |||
7671 | MemoryLocationsKind MLK = NO_LOCATIONS; | |||
7672 | assert(!isa<GEPOperator>(Obj) && "GEPs should have been stripped.")((void)0); | |||
7673 | if (isa<UndefValue>(Obj)) | |||
7674 | continue; | |||
7675 | if (auto *Arg = dyn_cast<Argument>(Obj)) { | |||
7676 | if (Arg->hasByValAttr()) | |||
7677 | MLK = NO_LOCAL_MEM; | |||
7678 | else | |||
7679 | MLK = NO_ARGUMENT_MEM; | |||
7680 | } else if (auto *GV = dyn_cast<GlobalValue>(Obj)) { | |||
7681 | // Reading constant memory is not treated as a read "effect" by the | |||
7682 | // function attr pass so we won't neither. Constants defined by TBAA are | |||
7683 | // similar. (We know we do not write it because it is constant.) | |||
7684 | if (auto *GVar = dyn_cast<GlobalVariable>(GV)) | |||
7685 | if (GVar->isConstant()) | |||
7686 | continue; | |||
7687 | ||||
7688 | if (GV->hasLocalLinkage()) | |||
7689 | MLK = NO_GLOBAL_INTERNAL_MEM; | |||
7690 | else | |||
7691 | MLK = NO_GLOBAL_EXTERNAL_MEM; | |||
7692 | } else if (isa<ConstantPointerNull>(Obj) && | |||
7693 | !NullPointerIsDefined(getAssociatedFunction(), | |||
7694 | Ptr.getType()->getPointerAddressSpace())) { | |||
7695 | continue; | |||
7696 | } else if (isa<AllocaInst>(Obj)) { | |||
7697 | MLK = NO_LOCAL_MEM; | |||
7698 | } else if (const auto *CB = dyn_cast<CallBase>(Obj)) { | |||
7699 | const auto &NoAliasAA = A.getAAFor<AANoAlias>( | |||
7700 | *this, IRPosition::callsite_returned(*CB), DepClassTy::OPTIONAL); | |||
7701 | if (NoAliasAA.isAssumedNoAlias()) | |||
7702 | MLK = NO_MALLOCED_MEM; | |||
7703 | else | |||
7704 | MLK = NO_UNKOWN_MEM; | |||
7705 | } else { | |||
7706 | MLK = NO_UNKOWN_MEM; | |||
7707 | } | |||
7708 | ||||
7709 | assert(MLK != NO_LOCATIONS && "No location specified!")((void)0); | |||
7710 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Ptr value can be categorized: "do { } while (false) | |||
7711 | << *Obj << " -> " << getMemoryLocationsAsStr(MLK)do { } while (false) | |||
7712 | << "\n")do { } while (false); | |||
7713 | updateStateAndAccessesMap(getState(), MLK, &I, Obj, Changed, | |||
7714 | getAccessKindFromInst(&I)); | |||
7715 | } | |||
7716 | ||||
7717 | LLVM_DEBUG(do { } while (false) | |||
7718 | dbgs() << "[AAMemoryLocation] Accessed locations with pointer locations: "do { } while (false) | |||
7719 | << getMemoryLocationsAsStr(State.getAssumed()) << "\n")do { } while (false); | |||
7720 | } | |||
7721 | ||||
7722 | void AAMemoryLocationImpl::categorizeArgumentPointerLocations( | |||
7723 | Attributor &A, CallBase &CB, AAMemoryLocation::StateType &AccessedLocs, | |||
7724 | bool &Changed) { | |||
7725 | for (unsigned ArgNo = 0, E = CB.getNumArgOperands(); ArgNo < E; ++ArgNo) { | |||
7726 | ||||
7727 | // Skip non-pointer arguments. | |||
7728 | const Value *ArgOp = CB.getArgOperand(ArgNo); | |||
7729 | if (!ArgOp->getType()->isPtrOrPtrVectorTy()) | |||
7730 | continue; | |||
7731 | ||||
7732 | // Skip readnone arguments. | |||
7733 | const IRPosition &ArgOpIRP = IRPosition::callsite_argument(CB, ArgNo); | |||
7734 | const auto &ArgOpMemLocationAA = | |||
7735 | A.getAAFor<AAMemoryBehavior>(*this, ArgOpIRP, DepClassTy::OPTIONAL); | |||
7736 | ||||
7737 | if (ArgOpMemLocationAA.isAssumedReadNone()) | |||
7738 | continue; | |||
7739 | ||||
7740 | // Categorize potentially accessed pointer arguments as if there was an | |||
7741 | // access instruction with them as pointer. | |||
7742 | categorizePtrValue(A, CB, *ArgOp, AccessedLocs, Changed); | |||
7743 | } | |||
7744 | } | |||
7745 | ||||
7746 | AAMemoryLocation::MemoryLocationsKind | |||
7747 | AAMemoryLocationImpl::categorizeAccessedLocations(Attributor &A, Instruction &I, | |||
7748 | bool &Changed) { | |||
7749 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Categorize accessed locations for "do { } while (false) | |||
7750 | << I << "\n")do { } while (false); | |||
7751 | ||||
7752 | AAMemoryLocation::StateType AccessedLocs; | |||
7753 | AccessedLocs.intersectAssumedBits(NO_LOCATIONS); | |||
7754 | ||||
7755 | if (auto *CB = dyn_cast<CallBase>(&I)) { | |||
7756 | ||||
7757 | // First check if we assume any memory is access is visible. | |||
7758 | const auto &CBMemLocationAA = A.getAAFor<AAMemoryLocation>( | |||
7759 | *this, IRPosition::callsite_function(*CB), DepClassTy::OPTIONAL); | |||
7760 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Categorize call site: " << Ido { } while (false) | |||
7761 | << " [" << CBMemLocationAA << "]\n")do { } while (false); | |||
7762 | ||||
7763 | if (CBMemLocationAA.isAssumedReadNone()) | |||
7764 | return NO_LOCATIONS; | |||
7765 | ||||
7766 | if (CBMemLocationAA.isAssumedInaccessibleMemOnly()) { | |||
7767 | updateStateAndAccessesMap(AccessedLocs, NO_INACCESSIBLE_MEM, &I, nullptr, | |||
7768 | Changed, getAccessKindFromInst(&I)); | |||
7769 | return AccessedLocs.getAssumed(); | |||
7770 | } | |||
7771 | ||||
7772 | uint32_t CBAssumedNotAccessedLocs = | |||
7773 | CBMemLocationAA.getAssumedNotAccessedLocation(); | |||
7774 | ||||
7775 | // Set the argmemonly and global bit as we handle them separately below. | |||
7776 | uint32_t CBAssumedNotAccessedLocsNoArgMem = | |||
7777 | CBAssumedNotAccessedLocs | NO_ARGUMENT_MEM | NO_GLOBAL_MEM; | |||
7778 | ||||
7779 | for (MemoryLocationsKind CurMLK = 1; CurMLK < NO_LOCATIONS; CurMLK *= 2) { | |||
7780 | if (CBAssumedNotAccessedLocsNoArgMem & CurMLK) | |||
7781 | continue; | |||
7782 | updateStateAndAccessesMap(AccessedLocs, CurMLK, &I, nullptr, Changed, | |||
7783 | getAccessKindFromInst(&I)); | |||
7784 | } | |||
7785 | ||||
7786 | // Now handle global memory if it might be accessed. This is slightly tricky | |||
7787 | // as NO_GLOBAL_MEM has multiple bits set. | |||
7788 | bool HasGlobalAccesses = ((~CBAssumedNotAccessedLocs) & NO_GLOBAL_MEM); | |||
7789 | if (HasGlobalAccesses) { | |||
7790 | auto AccessPred = [&](const Instruction *, const Value *Ptr, | |||
7791 | AccessKind Kind, MemoryLocationsKind MLK) { | |||
7792 | updateStateAndAccessesMap(AccessedLocs, MLK, &I, Ptr, Changed, | |||
7793 | getAccessKindFromInst(&I)); | |||
7794 | return true; | |||
7795 | }; | |||
7796 | if (!CBMemLocationAA.checkForAllAccessesToMemoryKind( | |||
7797 | AccessPred, inverseLocation(NO_GLOBAL_MEM, false, false))) | |||
7798 | return AccessedLocs.getWorstState(); | |||
7799 | } | |||
7800 | ||||
7801 | LLVM_DEBUG(do { } while (false) | |||
7802 | dbgs() << "[AAMemoryLocation] Accessed state before argument handling: "do { } while (false) | |||
7803 | << getMemoryLocationsAsStr(AccessedLocs.getAssumed()) << "\n")do { } while (false); | |||
7804 | ||||
7805 | // Now handle argument memory if it might be accessed. | |||
7806 | bool HasArgAccesses = ((~CBAssumedNotAccessedLocs) & NO_ARGUMENT_MEM); | |||
7807 | if (HasArgAccesses) | |||
7808 | categorizeArgumentPointerLocations(A, *CB, AccessedLocs, Changed); | |||
7809 | ||||
7810 | LLVM_DEBUG(do { } while (false) | |||
7811 | dbgs() << "[AAMemoryLocation] Accessed state after argument handling: "do { } while (false) | |||
7812 | << getMemoryLocationsAsStr(AccessedLocs.getAssumed()) << "\n")do { } while (false); | |||
7813 | ||||
7814 | return AccessedLocs.getAssumed(); | |||
7815 | } | |||
7816 | ||||
7817 | if (const Value *Ptr = getPointerOperand(&I, /* AllowVolatile */ true)) { | |||
7818 | LLVM_DEBUG(do { } while (false) | |||
7819 | dbgs() << "[AAMemoryLocation] Categorize memory access with pointer: "do { } while (false) | |||
7820 | << I << " [" << *Ptr << "]\n")do { } while (false); | |||
7821 | categorizePtrValue(A, I, *Ptr, AccessedLocs, Changed); | |||
7822 | return AccessedLocs.getAssumed(); | |||
7823 | } | |||
7824 | ||||
7825 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Failed to categorize instruction: "do { } while (false) | |||
7826 | << I << "\n")do { } while (false); | |||
7827 | updateStateAndAccessesMap(AccessedLocs, NO_UNKOWN_MEM, &I, nullptr, Changed, | |||
7828 | getAccessKindFromInst(&I)); | |||
7829 | return AccessedLocs.getAssumed(); | |||
7830 | } | |||
7831 | ||||
7832 | /// An AA to represent the memory behavior function attributes. | |||
7833 | struct AAMemoryLocationFunction final : public AAMemoryLocationImpl { | |||
7834 | AAMemoryLocationFunction(const IRPosition &IRP, Attributor &A) | |||
7835 | : AAMemoryLocationImpl(IRP, A) {} | |||
7836 | ||||
7837 | /// See AbstractAttribute::updateImpl(Attributor &A). | |||
7838 | virtual ChangeStatus updateImpl(Attributor &A) override { | |||
7839 | ||||
7840 | const auto &MemBehaviorAA = | |||
7841 | A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), DepClassTy::NONE); | |||
7842 | if (MemBehaviorAA.isAssumedReadNone()) { | |||
7843 | if (MemBehaviorAA.isKnownReadNone()) | |||
7844 | return indicateOptimisticFixpoint(); | |||
7845 | assert(isAssumedReadNone() &&((void)0) | |||
7846 | "AAMemoryLocation was not read-none but AAMemoryBehavior was!")((void)0); | |||
7847 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); | |||
7848 | return ChangeStatus::UNCHANGED; | |||
7849 | } | |||
7850 | ||||
7851 | // The current assumed state used to determine a change. | |||
7852 | auto AssumedState = getAssumed(); | |||
7853 | bool Changed = false; | |||
7854 | ||||
7855 | auto CheckRWInst = [&](Instruction &I) { | |||
7856 | MemoryLocationsKind MLK = categorizeAccessedLocations(A, I, Changed); | |||
7857 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Accessed locations for " << Ido { } while (false) | |||
7858 | << ": " << getMemoryLocationsAsStr(MLK) << "\n")do { } while (false); | |||
7859 | removeAssumedBits(inverseLocation(MLK, false, false)); | |||
7860 | // Stop once only the valid bit set in the *not assumed location*, thus | |||
7861 | // once we don't actually exclude any memory locations in the state. | |||
7862 | return getAssumedNotAccessedLocation() != VALID_STATE; | |||
7863 | }; | |||
7864 | ||||
7865 | bool UsedAssumedInformation = false; | |||
7866 | if (!A.checkForAllReadWriteInstructions(CheckRWInst, *this, | |||
7867 | UsedAssumedInformation)) | |||
7868 | return indicatePessimisticFixpoint(); | |||
7869 | ||||
7870 | Changed |= AssumedState != getAssumed(); | |||
7871 | return Changed ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; | |||
7872 | } | |||
7873 | ||||
7874 | /// See AbstractAttribute::trackStatistics() | |||
7875 | void trackStatistics() const override { | |||
7876 | if (isAssumedReadNone()) | |||
7877 | STATS_DECLTRACK_FN_ATTR(readnone){ static llvm::Statistic NumIRFunction_readnone = {"attributor" , "NumIRFunction_readnone", ("Number of " "functions" " marked '" "readnone" "'")};; ++(NumIRFunction_readnone); } | |||
7878 | else if (isAssumedArgMemOnly()) | |||
7879 | STATS_DECLTRACK_FN_ATTR(argmemonly){ static llvm::Statistic NumIRFunction_argmemonly = {"attributor" , "NumIRFunction_argmemonly", ("Number of " "functions" " marked '" "argmemonly" "'")};; ++(NumIRFunction_argmemonly); } | |||
7880 | else if (isAssumedInaccessibleMemOnly()) | |||
7881 | STATS_DECLTRACK_FN_ATTR(inaccessiblememonly){ static llvm::Statistic NumIRFunction_inaccessiblememonly = { "attributor", "NumIRFunction_inaccessiblememonly", ("Number of " "functions" " marked '" "inaccessiblememonly" "'")};; ++(NumIRFunction_inaccessiblememonly ); } | |||
7882 | else if (isAssumedInaccessibleOrArgMemOnly()) | |||
7883 | STATS_DECLTRACK_FN_ATTR(inaccessiblememorargmemonly){ static llvm::Statistic NumIRFunction_inaccessiblememorargmemonly = {"attributor", "NumIRFunction_inaccessiblememorargmemonly" , ("Number of " "functions" " marked '" "inaccessiblememorargmemonly" "'")};; ++(NumIRFunction_inaccessiblememorargmemonly); } | |||
7884 | } | |||
7885 | }; | |||
7886 | ||||
7887 | /// AAMemoryLocation attribute for call sites. | |||
7888 | struct AAMemoryLocationCallSite final : AAMemoryLocationImpl { | |||
7889 | AAMemoryLocationCallSite(const IRPosition &IRP, Attributor &A) | |||
7890 | : AAMemoryLocationImpl(IRP, A) {} | |||
7891 | ||||
7892 | /// See AbstractAttribute::initialize(...). | |||
7893 | void initialize(Attributor &A) override { | |||
7894 | AAMemoryLocationImpl::initialize(A); | |||
7895 | Function *F = getAssociatedFunction(); | |||
7896 | if (!F || F->isDeclaration()) | |||
7897 | indicatePessimisticFixpoint(); | |||
7898 | } | |||
7899 | ||||
7900 | /// See AbstractAttribute::updateImpl(...). | |||
7901 | ChangeStatus updateImpl(Attributor &A) override { | |||
7902 | // TODO: Once we have call site specific value information we can provide | |||
7903 | // call site specific liveness liveness information and then it makes | |||
7904 | // sense to specialize attributes for call sites arguments instead of | |||
7905 | // redirecting requests to the callee argument. | |||
7906 | Function *F = getAssociatedFunction(); | |||
7907 | const IRPosition &FnPos = IRPosition::function(*F); | |||
7908 | auto &FnAA = | |||
7909 | A.getAAFor<AAMemoryLocation>(*this, FnPos, DepClassTy::REQUIRED); | |||
7910 | bool Changed = false; | |||
7911 | auto AccessPred = [&](const Instruction *I, const Value *Ptr, | |||
7912 | AccessKind Kind, MemoryLocationsKind MLK) { | |||
7913 | updateStateAndAccessesMap(getState(), MLK, I, Ptr, Changed, | |||
7914 | getAccessKindFromInst(I)); | |||
7915 | return true; | |||
7916 | }; | |||
7917 | if (!FnAA.checkForAllAccessesToMemoryKind(AccessPred, ALL_LOCATIONS)) | |||
7918 | return indicatePessimisticFixpoint(); | |||
7919 | return Changed ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; | |||
7920 | } | |||
7921 | ||||
7922 | /// See AbstractAttribute::trackStatistics() | |||
7923 | void trackStatistics() const override { | |||
7924 | if (isAssumedReadNone()) | |||
7925 | STATS_DECLTRACK_CS_ATTR(readnone){ static llvm::Statistic NumIRCS_readnone = {"attributor", "NumIRCS_readnone" , ("Number of " "call site" " marked '" "readnone" "'")};; ++ (NumIRCS_readnone); } | |||
7926 | } | |||
7927 | }; | |||
7928 | ||||
7929 | /// ------------------ Value Constant Range Attribute ------------------------- | |||
7930 | ||||
7931 | struct AAValueConstantRangeImpl : AAValueConstantRange { | |||
7932 | using StateType = IntegerRangeState; | |||
7933 | AAValueConstantRangeImpl(const IRPosition &IRP, Attributor &A) | |||
7934 | : AAValueConstantRange(IRP, A) {} | |||
7935 | ||||
7936 | /// See AbstractAttribute::initialize(..). | |||
7937 | void initialize(Attributor &A) override { | |||
7938 | if (A.hasSimplificationCallback(getIRPosition())) { | |||
7939 | indicatePessimisticFixpoint(); | |||
7940 | return; | |||
7941 | } | |||
7942 | ||||
7943 | // Intersect a range given by SCEV. | |||
7944 | intersectKnown(getConstantRangeFromSCEV(A, getCtxI())); | |||
7945 | ||||
7946 | // Intersect a range given by LVI. | |||
7947 | intersectKnown(getConstantRangeFromLVI(A, getCtxI())); | |||
7948 | } | |||
7949 | ||||
7950 | /// See AbstractAttribute::getAsStr(). | |||
7951 | const std::string getAsStr() const override { | |||
7952 | std::string Str; | |||
7953 | llvm::raw_string_ostream OS(Str); | |||
7954 | OS << "range(" << getBitWidth() << ")<"; | |||
7955 | getKnown().print(OS); | |||
7956 | OS << " / "; | |||
7957 | getAssumed().print(OS); | |||
7958 | OS << ">"; | |||
7959 | return OS.str(); | |||
7960 | } | |||
7961 | ||||
7962 | /// Helper function to get a SCEV expr for the associated value at program | |||
7963 | /// point \p I. | |||
7964 | const SCEV *getSCEV(Attributor &A, const Instruction *I = nullptr) const { | |||
7965 | if (!getAnchorScope()) | |||
7966 | return nullptr; | |||
7967 | ||||
7968 | ScalarEvolution *SE = | |||
7969 | A.getInfoCache().getAnalysisResultForFunction<ScalarEvolutionAnalysis>( | |||
7970 | *getAnchorScope()); | |||
7971 | ||||
7972 | LoopInfo *LI = A.getInfoCache().getAnalysisResultForFunction<LoopAnalysis>( | |||
7973 | *getAnchorScope()); | |||
7974 | ||||
7975 | if (!SE || !LI) | |||
7976 | return nullptr; | |||
7977 | ||||
7978 | const SCEV *S = SE->getSCEV(&getAssociatedValue()); | |||
7979 | if (!I) | |||
7980 | return S; | |||
7981 | ||||
7982 | return SE->getSCEVAtScope(S, LI->getLoopFor(I->getParent())); | |||
7983 | } | |||
7984 | ||||
7985 | /// Helper function to get a range from SCEV for the associated value at | |||
7986 | /// program point \p I. | |||
7987 | ConstantRange getConstantRangeFromSCEV(Attributor &A, | |||
7988 | const Instruction *I = nullptr) const { | |||
7989 | if (!getAnchorScope()) | |||
7990 | return getWorstState(getBitWidth()); | |||
7991 | ||||
7992 | ScalarEvolution *SE = | |||
7993 | A.getInfoCache().getAnalysisResultForFunction<ScalarEvolutionAnalysis>( | |||
7994 | *getAnchorScope()); | |||
7995 | ||||
7996 | const SCEV *S = getSCEV(A, I); | |||
7997 | if (!SE || !S) | |||
7998 | return getWorstState(getBitWidth()); | |||
7999 | ||||
8000 | return SE->getUnsignedRange(S); | |||
8001 | } | |||
8002 | ||||
8003 | /// Helper function to get a range from LVI for the associated value at | |||
8004 | /// program point \p I. | |||
8005 | ConstantRange | |||
8006 | getConstantRangeFromLVI(Attributor &A, | |||
8007 | const Instruction *CtxI = nullptr) const { | |||
8008 | if (!getAnchorScope()) | |||
8009 | return getWorstState(getBitWidth()); | |||
8010 | ||||
8011 | LazyValueInfo *LVI = | |||
8012 | A.getInfoCache().getAnalysisResultForFunction<LazyValueAnalysis>( | |||
8013 | *getAnchorScope()); | |||
8014 | ||||
8015 | if (!LVI || !CtxI) | |||
8016 | return getWorstState(getBitWidth()); | |||
8017 | return LVI->getConstantRange(&getAssociatedValue(), | |||
8018 | const_cast<Instruction *>(CtxI)); | |||
8019 | } | |||
8020 | ||||
8021 | /// Return true if \p CtxI is valid for querying outside analyses. | |||
8022 | /// This basically makes sure we do not ask intra-procedural analysis | |||
8023 | /// about a context in the wrong function or a context that violates | |||
8024 | /// dominance assumptions they might have. The \p AllowAACtxI flag indicates | |||
8025 | /// if the original context of this AA is OK or should be considered invalid. | |||
8026 | bool isValidCtxInstructionForOutsideAnalysis(Attributor &A, | |||
8027 | const Instruction *CtxI, | |||
8028 | bool AllowAACtxI) const { | |||
8029 | if (!CtxI || (!AllowAACtxI && CtxI == getCtxI())) | |||
8030 | return false; | |||
8031 | ||||
8032 | // Our context might be in a different function, neither intra-procedural | |||
8033 | // analysis (ScalarEvolution nor LazyValueInfo) can handle that. | |||
8034 | if (!AA::isValidInScope(getAssociatedValue(), CtxI->getFunction())) | |||
8035 | return false; | |||
8036 | ||||
8037 | // If the context is not dominated by the value there are paths to the | |||
8038 | // context that do not define the value. This cannot be handled by | |||
8039 | // LazyValueInfo so we need to bail. | |||
8040 | if (auto *I = dyn_cast<Instruction>(&getAssociatedValue())) { | |||
8041 | InformationCache &InfoCache = A.getInfoCache(); | |||
8042 | const DominatorTree *DT = | |||
8043 | InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>( | |||
8044 | *I->getFunction()); | |||
8045 | return DT && DT->dominates(I, CtxI); | |||
8046 | } | |||
8047 | ||||
8048 | return true; | |||
8049 | } | |||
8050 | ||||
8051 | /// See AAValueConstantRange::getKnownConstantRange(..). | |||
8052 | ConstantRange | |||
8053 | getKnownConstantRange(Attributor &A, | |||
8054 | const Instruction *CtxI = nullptr) const override { | |||
8055 | if (!isValidCtxInstructionForOutsideAnalysis(A, CtxI, | |||
8056 | /* AllowAACtxI */ false)) | |||
8057 | return getKnown(); | |||
8058 | ||||
8059 | ConstantRange LVIR = getConstantRangeFromLVI(A, CtxI); | |||
8060 | ConstantRange SCEVR = getConstantRangeFromSCEV(A, CtxI); | |||
8061 | return getKnown().intersectWith(SCEVR).intersectWith(LVIR); | |||
8062 | } | |||
8063 | ||||
8064 | /// See AAValueConstantRange::getAssumedConstantRange(..). | |||
8065 | ConstantRange | |||
8066 | getAssumedConstantRange(Attributor &A, | |||
8067 | const Instruction *CtxI = nullptr) const override { | |||
8068 | // TODO: Make SCEV use Attributor assumption. | |||
8069 | // We may be able to bound a variable range via assumptions in | |||
8070 | // Attributor. ex.) If x is assumed to be in [1, 3] and y is known to | |||
8071 | // evolve to x^2 + x, then we can say that y is in [2, 12]. | |||
8072 | if (!isValidCtxInstructionForOutsideAnalysis(A, CtxI, | |||
8073 | /* AllowAACtxI */ false)) | |||
8074 | return getAssumed(); | |||
8075 | ||||
8076 | ConstantRange LVIR = getConstantRangeFromLVI(A, CtxI); | |||
8077 | ConstantRange SCEVR = getConstantRangeFromSCEV(A, CtxI); | |||
8078 | return getAssumed().intersectWith(SCEVR).intersectWith(LVIR); | |||
8079 | } | |||
8080 | ||||
8081 | /// Helper function to create MDNode for range metadata. | |||
8082 | static MDNode * | |||
8083 | getMDNodeForConstantRange(Type *Ty, LLVMContext &Ctx, | |||
8084 | const ConstantRange &AssumedConstantRange) { | |||
8085 | Metadata *LowAndHigh[] = {ConstantAsMetadata::get(ConstantInt::get( | |||
8086 | Ty, AssumedConstantRange.getLower())), | |||
8087 | ConstantAsMetadata::get(ConstantInt::get( | |||
8088 | Ty, AssumedConstantRange.getUpper()))}; | |||
8089 | return MDNode::get(Ctx, LowAndHigh); | |||
8090 | } | |||
8091 | ||||
8092 | /// Return true if \p Assumed is included in \p KnownRanges. | |||
8093 | static bool isBetterRange(const ConstantRange &Assumed, MDNode *KnownRanges) { | |||
8094 | ||||
8095 | if (Assumed.isFullSet()) | |||
8096 | return false; | |||
8097 | ||||
8098 | if (!KnownRanges) | |||
8099 | return true; | |||
8100 | ||||
8101 | // If multiple ranges are annotated in IR, we give up to annotate assumed | |||
8102 | // range for now. | |||
8103 | ||||
8104 | // TODO: If there exists a known range which containts assumed range, we | |||
8105 | // can say assumed range is better. | |||
8106 | if (KnownRanges->getNumOperands() > 2) | |||
8107 | return false; | |||
8108 | ||||
8109 | ConstantInt *Lower = | |||
8110 | mdconst::extract<ConstantInt>(KnownRanges->getOperand(0)); | |||
8111 | ConstantInt *Upper = | |||
8112 | mdconst::extract<ConstantInt>(KnownRanges->getOperand(1)); | |||
8113 | ||||
8114 | ConstantRange Known(Lower->getValue(), Upper->getValue()); | |||
8115 | return Known.contains(Assumed) && Known != Assumed; | |||
8116 | } | |||
8117 | ||||
8118 | /// Helper function to set range metadata. | |||
8119 | static bool | |||
8120 | setRangeMetadataIfisBetterRange(Instruction *I, | |||
8121 | const ConstantRange &AssumedConstantRange) { | |||
8122 | auto *OldRangeMD = I->getMetadata(LLVMContext::MD_range); | |||
8123 | if (isBetterRange(AssumedConstantRange, OldRangeMD)) { | |||
8124 | if (!AssumedConstantRange.isEmptySet()) { | |||
8125 | I->setMetadata(LLVMContext::MD_range, | |||
8126 | getMDNodeForConstantRange(I->getType(), I->getContext(), | |||
8127 | AssumedConstantRange)); | |||
8128 | return true; | |||
8129 | } | |||
8130 | } | |||
8131 | return false; | |||
8132 | } | |||
8133 | ||||
8134 | /// See AbstractAttribute::manifest() | |||
8135 | ChangeStatus manifest(Attributor &A) override { | |||
8136 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | |||
8137 | ConstantRange AssumedConstantRange = getAssumedConstantRange(A); | |||
8138 | assert(!AssumedConstantRange.isFullSet() && "Invalid state")((void)0); | |||
8139 | ||||
8140 | auto &V = getAssociatedValue(); | |||
8141 | if (!AssumedConstantRange.isEmptySet() && | |||
8142 | !AssumedConstantRange.isSingleElement()) { | |||
8143 | if (Instruction *I = dyn_cast<Instruction>(&V)) { | |||
8144 | assert(I == getCtxI() && "Should not annotate an instruction which is "((void)0) | |||
8145 | "not the context instruction")((void)0); | |||
8146 | if (isa<CallInst>(I) || isa<LoadInst>(I)) | |||
8147 | if (setRangeMetadataIfisBetterRange(I, AssumedConstantRange)) | |||
8148 | Changed = ChangeStatus::CHANGED; | |||
8149 | } | |||
8150 | } | |||
8151 | ||||
8152 | return Changed; | |||
8153 | } | |||
8154 | }; | |||
8155 | ||||
8156 | struct AAValueConstantRangeArgument final | |||
8157 | : AAArgumentFromCallSiteArguments< | |||
8158 | AAValueConstantRange, AAValueConstantRangeImpl, IntegerRangeState, | |||
8159 | true /* BridgeCallBaseContext */> { | |||
8160 | using Base = AAArgumentFromCallSiteArguments< | |||
8161 | AAValueConstantRange, AAValueConstantRangeImpl, IntegerRangeState, | |||
8162 | true /* BridgeCallBaseContext */>; | |||
8163 | AAValueConstantRangeArgument(const IRPosition &IRP, Attributor &A) | |||
8164 | : Base(IRP, A) {} | |||
8165 | ||||
8166 | /// See AbstractAttribute::initialize(..). | |||
8167 | void initialize(Attributor &A) override { | |||
8168 | if (!getAnchorScope() || getAnchorScope()->isDeclaration()) { | |||
8169 | indicatePessimisticFixpoint(); | |||
8170 | } else { | |||
8171 | Base::initialize(A); | |||
8172 | } | |||
8173 | } | |||
8174 | ||||
8175 | /// See AbstractAttribute::trackStatistics() | |||
8176 | void trackStatistics() const override { | |||
8177 | STATS_DECLTRACK_ARG_ATTR(value_range){ static llvm::Statistic NumIRArguments_value_range = {"attributor" , "NumIRArguments_value_range", ("Number of " "arguments" " marked '" "value_range" "'")};; ++(NumIRArguments_value_range); } | |||
8178 | } | |||
8179 | }; | |||
8180 | ||||
8181 | struct AAValueConstantRangeReturned | |||
8182 | : AAReturnedFromReturnedValues<AAValueConstantRange, | |||
8183 | AAValueConstantRangeImpl, | |||
8184 | AAValueConstantRangeImpl::StateType, | |||
8185 | /* PropogateCallBaseContext */ true> { | |||
8186 | using Base = | |||
8187 | AAReturnedFromReturnedValues<AAValueConstantRange, | |||
8188 | AAValueConstantRangeImpl, | |||
8189 | AAValueConstantRangeImpl::StateType, | |||
8190 | /* PropogateCallBaseContext */ true>; | |||
8191 | AAValueConstantRangeReturned(const IRPosition &IRP, Attributor &A) | |||
8192 | : Base(IRP, A) {} | |||
8193 | ||||
8194 | /// See AbstractAttribute::initialize(...). | |||
8195 | void initialize(Attributor &A) override {} | |||
8196 | ||||
8197 | /// See AbstractAttribute::trackStatistics() | |||
8198 | void trackStatistics() const override { | |||
8199 | STATS_DECLTRACK_FNRET_ATTR(value_range){ static llvm::Statistic NumIRFunctionReturn_value_range = {"attributor" , "NumIRFunctionReturn_value_range", ("Number of " "function returns" " marked '" "value_range" "'")};; ++(NumIRFunctionReturn_value_range ); } | |||
8200 | } | |||
8201 | }; | |||
8202 | ||||
8203 | struct AAValueConstantRangeFloating : AAValueConstantRangeImpl { | |||
8204 | AAValueConstantRangeFloating(const IRPosition &IRP, Attributor &A) | |||
8205 | : AAValueConstantRangeImpl(IRP, A) {} | |||
8206 | ||||
8207 | /// See AbstractAttribute::initialize(...). | |||
8208 | void initialize(Attributor &A) override { | |||
8209 | AAValueConstantRangeImpl::initialize(A); | |||
8210 | if (isAtFixpoint()) | |||
8211 | return; | |||
8212 | ||||
8213 | Value &V = getAssociatedValue(); | |||
8214 | ||||
8215 | if (auto *C = dyn_cast<ConstantInt>(&V)) { | |||
8216 | unionAssumed(ConstantRange(C->getValue())); | |||
8217 | indicateOptimisticFixpoint(); | |||
8218 | return; | |||
8219 | } | |||
8220 | ||||
8221 | if (isa<UndefValue>(&V)) { | |||
8222 | // Collapse the undef state to 0. | |||
8223 | unionAssumed(ConstantRange(APInt(getBitWidth(), 0))); | |||
8224 | indicateOptimisticFixpoint(); | |||
8225 | return; | |||
8226 | } | |||
8227 | ||||
8228 | if (isa<CallBase>(&V)) | |||
8229 | return; | |||
8230 | ||||
8231 | if (isa<BinaryOperator>(&V) || isa<CmpInst>(&V) || isa<CastInst>(&V)) | |||
8232 | return; | |||
8233 | ||||
8234 | // If it is a load instruction with range metadata, use it. | |||
8235 | if (LoadInst *LI = dyn_cast<LoadInst>(&V)) | |||
8236 | if (auto *RangeMD = LI->getMetadata(LLVMContext::MD_range)) { | |||
8237 | intersectKnown(getConstantRangeFromMetadata(*RangeMD)); | |||
8238 | return; | |||
8239 | } | |||
8240 | ||||
8241 | // We can work with PHI and select instruction as we traverse their operands | |||
8242 | // during update. | |||
8243 | if (isa<SelectInst>(V) || isa<PHINode>(V)) | |||
8244 | return; | |||
8245 | ||||
8246 | // Otherwise we give up. | |||
8247 | indicatePessimisticFixpoint(); | |||
8248 | ||||
8249 | LLVM_DEBUG(dbgs() << "[AAValueConstantRange] We give up: "do { } while (false) | |||
8250 | << getAssociatedValue() << "\n")do { } while (false); | |||
8251 | } | |||
8252 | ||||
8253 | bool calculateBinaryOperator( | |||
8254 | Attributor &A, BinaryOperator *BinOp, IntegerRangeState &T, | |||
8255 | const Instruction *CtxI, | |||
8256 | SmallVectorImpl<const AAValueConstantRange *> &QuerriedAAs) { | |||
8257 | Value *LHS = BinOp->getOperand(0); | |||
8258 | Value *RHS = BinOp->getOperand(1); | |||
8259 | ||||
8260 | // Simplify the operands first. | |||
8261 | bool UsedAssumedInformation = false; | |||
8262 | const auto &SimplifiedLHS = | |||
8263 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), | |||
8264 | *this, UsedAssumedInformation); | |||
8265 | if (!SimplifiedLHS.hasValue()) | |||
8266 | return true; | |||
8267 | if (!SimplifiedLHS.getValue()) | |||
8268 | return false; | |||
8269 | LHS = *SimplifiedLHS; | |||
8270 | ||||
8271 | const auto &SimplifiedRHS = | |||
8272 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), | |||
8273 | *this, UsedAssumedInformation); | |||
8274 | if (!SimplifiedRHS.hasValue()) | |||
8275 | return true; | |||
8276 | if (!SimplifiedRHS.getValue()) | |||
8277 | return false; | |||
8278 | RHS = *SimplifiedRHS; | |||
8279 | ||||
8280 | // TODO: Allow non integers as well. | |||
8281 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) | |||
8282 | return false; | |||
8283 | ||||
8284 | auto &LHSAA = A.getAAFor<AAValueConstantRange>( | |||
8285 | *this, IRPosition::value(*LHS, getCallBaseContext()), | |||
8286 | DepClassTy::REQUIRED); | |||
8287 | QuerriedAAs.push_back(&LHSAA); | |||
8288 | auto LHSAARange = LHSAA.getAssumedConstantRange(A, CtxI); | |||
8289 | ||||
8290 | auto &RHSAA = A.getAAFor<AAValueConstantRange>( | |||
8291 | *this, IRPosition::value(*RHS, getCallBaseContext()), | |||
8292 | DepClassTy::REQUIRED); | |||
8293 | QuerriedAAs.push_back(&RHSAA); | |||
8294 | auto RHSAARange = RHSAA.getAssumedConstantRange(A, CtxI); | |||
8295 | ||||
8296 | auto AssumedRange = LHSAARange.binaryOp(BinOp->getOpcode(), RHSAARange); | |||
8297 | ||||
8298 | T.unionAssumed(AssumedRange); | |||
8299 | ||||
8300 | // TODO: Track a known state too. | |||
8301 | ||||
8302 | return T.isValidState(); | |||
8303 | } | |||
8304 | ||||
8305 | bool calculateCastInst( | |||
8306 | Attributor &A, CastInst *CastI, IntegerRangeState &T, | |||
8307 | const Instruction *CtxI, | |||
8308 | SmallVectorImpl<const AAValueConstantRange *> &QuerriedAAs) { | |||
8309 | assert(CastI->getNumOperands() == 1 && "Expected cast to be unary!")((void)0); | |||
8310 | // TODO: Allow non integers as well. | |||
8311 | Value *OpV = CastI->getOperand(0); | |||
8312 | ||||
8313 | // Simplify the operand first. | |||
8314 | bool UsedAssumedInformation = false; | |||
8315 | const auto &SimplifiedOpV = | |||
8316 | A.getAssumedSimplified(IRPosition::value(*OpV, getCallBaseContext()), | |||
8317 | *this, UsedAssumedInformation); | |||
8318 | if (!SimplifiedOpV.hasValue()) | |||
8319 | return true; | |||
8320 | if (!SimplifiedOpV.getValue()) | |||
8321 | return false; | |||
8322 | OpV = *SimplifiedOpV; | |||
8323 | ||||
8324 | if (!OpV->getType()->isIntegerTy()) | |||
8325 | return false; | |||
8326 | ||||
8327 | auto &OpAA = A.getAAFor<AAValueConstantRange>( | |||
8328 | *this, IRPosition::value(*OpV, getCallBaseContext()), | |||
8329 | DepClassTy::REQUIRED); | |||
8330 | QuerriedAAs.push_back(&OpAA); | |||
8331 | T.unionAssumed( | |||
8332 | OpAA.getAssumed().castOp(CastI->getOpcode(), getState().getBitWidth())); | |||
8333 | return T.isValidState(); | |||
8334 | } | |||
8335 | ||||
8336 | bool | |||
8337 | calculateCmpInst(Attributor &A, CmpInst *CmpI, IntegerRangeState &T, | |||
8338 | const Instruction *CtxI, | |||
8339 | SmallVectorImpl<const AAValueConstantRange *> &QuerriedAAs) { | |||
8340 | Value *LHS = CmpI->getOperand(0); | |||
8341 | Value *RHS = CmpI->getOperand(1); | |||
8342 | ||||
8343 | // Simplify the operands first. | |||
8344 | bool UsedAssumedInformation = false; | |||
8345 | const auto &SimplifiedLHS = | |||
8346 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), | |||
8347 | *this, UsedAssumedInformation); | |||
8348 | if (!SimplifiedLHS.hasValue()) | |||
8349 | return true; | |||
8350 | if (!SimplifiedLHS.getValue()) | |||
8351 | return false; | |||
8352 | LHS = *SimplifiedLHS; | |||
8353 | ||||
8354 | const auto &SimplifiedRHS = | |||
8355 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), | |||
8356 | *this, UsedAssumedInformation); | |||
8357 | if (!SimplifiedRHS.hasValue()) | |||
8358 | return true; | |||
8359 | if (!SimplifiedRHS.getValue()) | |||
8360 | return false; | |||
8361 | RHS = *SimplifiedRHS; | |||
8362 | ||||
8363 | // TODO: Allow non integers as well. | |||
8364 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) | |||
8365 | return false; | |||
8366 | ||||
8367 | auto &LHSAA = A.getAAFor<AAValueConstantRange>( | |||
8368 | *this, IRPosition::value(*LHS, getCallBaseContext()), | |||
8369 | DepClassTy::REQUIRED); | |||
8370 | QuerriedAAs.push_back(&LHSAA); | |||
8371 | auto &RHSAA = A.getAAFor<AAValueConstantRange>( | |||
8372 | *this, IRPosition::value(*RHS, getCallBaseContext()), | |||
8373 | DepClassTy::REQUIRED); | |||
8374 | QuerriedAAs.push_back(&RHSAA); | |||
8375 | auto LHSAARange = LHSAA.getAssumedConstantRange(A, CtxI); | |||
8376 | auto RHSAARange = RHSAA.getAssumedConstantRange(A, CtxI); | |||
8377 | ||||
8378 | // If one of them is empty set, we can't decide. | |||
8379 | if (LHSAARange.isEmptySet() || RHSAARange.isEmptySet()) | |||
8380 | return true; | |||
8381 | ||||
8382 | bool MustTrue = false, MustFalse = false; | |||
8383 | ||||
8384 | auto AllowedRegion = | |||
8385 | ConstantRange::makeAllowedICmpRegion(CmpI->getPredicate(), RHSAARange); | |||
8386 | ||||
8387 | if (AllowedRegion.intersectWith(LHSAARange).isEmptySet()) | |||
8388 | MustFalse = true; | |||
8389 | ||||
8390 | if (LHSAARange.icmp(CmpI->getPredicate(), RHSAARange)) | |||
8391 | MustTrue = true; | |||
8392 | ||||
8393 | assert((!MustTrue || !MustFalse) &&((void)0) | |||
8394 | "Either MustTrue or MustFalse should be false!")((void)0); | |||
8395 | ||||
8396 | if (MustTrue) | |||
8397 | T.unionAssumed(ConstantRange(APInt(/* numBits */ 1, /* val */ 1))); | |||
8398 | else if (MustFalse) | |||
8399 | T.unionAssumed(ConstantRange(APInt(/* numBits */ 1, /* val */ 0))); | |||
8400 | else | |||
8401 | T.unionAssumed(ConstantRange(/* BitWidth */ 1, /* isFullSet */ true)); | |||
8402 | ||||
8403 | LLVM_DEBUG(dbgs() << "[AAValueConstantRange] " << *CmpI << " " << LHSAAdo { } while (false) | |||
8404 | << " " << RHSAA << "\n")do { } while (false); | |||
8405 | ||||
8406 | // TODO: Track a known state too. | |||
8407 | return T.isValidState(); | |||
8408 | } | |||
8409 | ||||
8410 | /// See AbstractAttribute::updateImpl(...). | |||
8411 | ChangeStatus updateImpl(Attributor &A) override { | |||
8412 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, | |||
8413 | IntegerRangeState &T, bool Stripped) -> bool { | |||
8414 | Instruction *I = dyn_cast<Instruction>(&V); | |||
8415 | if (!I || isa<CallBase>(I)) { | |||
8416 | ||||
8417 | // Simplify the operand first. | |||
8418 | bool UsedAssumedInformation = false; | |||
8419 | const auto &SimplifiedOpV = | |||
8420 | A.getAssumedSimplified(IRPosition::value(V, getCallBaseContext()), | |||
8421 | *this, UsedAssumedInformation); | |||
8422 | if (!SimplifiedOpV.hasValue()) | |||
8423 | return true; | |||
8424 | if (!SimplifiedOpV.getValue()) | |||
8425 | return false; | |||
8426 | Value *VPtr = *SimplifiedOpV; | |||
8427 | ||||
8428 | // If the value is not instruction, we query AA to Attributor. | |||
8429 | const auto &AA = A.getAAFor<AAValueConstantRange>( | |||
8430 | *this, IRPosition::value(*VPtr, getCallBaseContext()), | |||
8431 | DepClassTy::REQUIRED); | |||
8432 | ||||
8433 | // Clamp operator is not used to utilize a program point CtxI. | |||
8434 | T.unionAssumed(AA.getAssumedConstantRange(A, CtxI)); | |||
8435 | ||||
8436 | return T.isValidState(); | |||
8437 | } | |||
8438 | ||||
8439 | SmallVector<const AAValueConstantRange *, 4> QuerriedAAs; | |||
8440 | if (auto *BinOp = dyn_cast<BinaryOperator>(I)) { | |||
8441 | if (!calculateBinaryOperator(A, BinOp, T, CtxI, QuerriedAAs)) | |||
8442 | return false; | |||
8443 | } else if (auto *CmpI = dyn_cast<CmpInst>(I)) { | |||
8444 | if (!calculateCmpInst(A, CmpI, T, CtxI, QuerriedAAs)) | |||
8445 | return false; | |||
8446 | } else if (auto *CastI = dyn_cast<CastInst>(I)) { | |||
8447 | if (!calculateCastInst(A, CastI, T, CtxI, QuerriedAAs)) | |||
8448 | return false; | |||
8449 | } else { | |||
8450 | // Give up with other instructions. | |||
8451 | // TODO: Add other instructions | |||
8452 | ||||
8453 | T.indicatePessimisticFixpoint(); | |||
8454 | return false; | |||
8455 | } | |||
8456 | ||||
8457 | // Catch circular reasoning in a pessimistic way for now. | |||
8458 | // TODO: Check how the range evolves and if we stripped anything, see also | |||
8459 | // AADereferenceable or AAAlign for similar situations. | |||
8460 | for (const AAValueConstantRange *QueriedAA : QuerriedAAs) { | |||
8461 | if (QueriedAA != this) | |||
8462 | continue; | |||
8463 | // If we are in a stady state we do not need to worry. | |||
8464 | if (T.getAssumed() == getState().getAssumed()) | |||
8465 | continue; | |||
8466 | T.indicatePessimisticFixpoint(); | |||
8467 | } | |||
8468 | ||||
8469 | return T.isValidState(); | |||
8470 | }; | |||
8471 | ||||
8472 | IntegerRangeState T(getBitWidth()); | |||
8473 | ||||
8474 | if (!genericValueTraversal<IntegerRangeState>(A, getIRPosition(), *this, T, | |||
8475 | VisitValueCB, getCtxI(), | |||
8476 | /* UseValueSimplify */ false)) | |||
8477 | return indicatePessimisticFixpoint(); | |||
8478 | ||||
8479 | return clampStateAndIndicateChange(getState(), T); | |||
8480 | } | |||
8481 | ||||
8482 | /// See AbstractAttribute::trackStatistics() | |||
8483 | void trackStatistics() const override { | |||
8484 | STATS_DECLTRACK_FLOATING_ATTR(value_range){ static llvm::Statistic NumIRFloating_value_range = {"attributor" , "NumIRFloating_value_range", ("Number of floating values known to be '" "value_range" "'")};; ++(NumIRFloating_value_range); } | |||
8485 | } | |||
8486 | }; | |||
8487 | ||||
8488 | struct AAValueConstantRangeFunction : AAValueConstantRangeImpl { | |||
8489 | AAValueConstantRangeFunction(const IRPosition &IRP, Attributor &A) | |||
8490 | : AAValueConstantRangeImpl(IRP, A) {} | |||
8491 | ||||
8492 | /// See AbstractAttribute::initialize(...). | |||
8493 | ChangeStatus updateImpl(Attributor &A) override { | |||
8494 | llvm_unreachable("AAValueConstantRange(Function|CallSite)::updateImpl will "__builtin_unreachable() | |||
8495 | "not be called")__builtin_unreachable(); | |||
8496 | } | |||
8497 | ||||
8498 | /// See AbstractAttribute::trackStatistics() | |||
8499 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(value_range){ static llvm::Statistic NumIRFunction_value_range = {"attributor" , "NumIRFunction_value_range", ("Number of " "functions" " marked '" "value_range" "'")};; ++(NumIRFunction_value_range); } } | |||
8500 | }; | |||
8501 | ||||
8502 | struct AAValueConstantRangeCallSite : AAValueConstantRangeFunction { | |||
8503 | AAValueConstantRangeCallSite(const IRPosition &IRP, Attributor &A) | |||
8504 | : AAValueConstantRangeFunction(IRP, A) {} | |||
8505 | ||||
8506 | /// See AbstractAttribute::trackStatistics() | |||
8507 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(value_range){ static llvm::Statistic NumIRCS_value_range = {"attributor", "NumIRCS_value_range", ("Number of " "call site" " marked '" "value_range" "'")};; ++(NumIRCS_value_range); } } | |||
8508 | }; | |||
8509 | ||||
8510 | struct AAValueConstantRangeCallSiteReturned | |||
8511 | : AACallSiteReturnedFromReturned<AAValueConstantRange, | |||
8512 | AAValueConstantRangeImpl, | |||
8513 | AAValueConstantRangeImpl::StateType, | |||
8514 | /* IntroduceCallBaseContext */ true> { | |||
8515 | AAValueConstantRangeCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
8516 | : AACallSiteReturnedFromReturned<AAValueConstantRange, | |||
8517 | AAValueConstantRangeImpl, | |||
8518 | AAValueConstantRangeImpl::StateType, | |||
8519 | /* IntroduceCallBaseContext */ true>(IRP, | |||
8520 | A) { | |||
8521 | } | |||
8522 | ||||
8523 | /// See AbstractAttribute::initialize(...). | |||
8524 | void initialize(Attributor &A) override { | |||
8525 | // If it is a load instruction with range metadata, use the metadata. | |||
8526 | if (CallInst *CI = dyn_cast<CallInst>(&getAssociatedValue())) | |||
8527 | if (auto *RangeMD = CI->getMetadata(LLVMContext::MD_range)) | |||
8528 | intersectKnown(getConstantRangeFromMetadata(*RangeMD)); | |||
8529 | ||||
8530 | AAValueConstantRangeImpl::initialize(A); | |||
8531 | } | |||
8532 | ||||
8533 | /// See AbstractAttribute::trackStatistics() | |||
8534 | void trackStatistics() const override { | |||
8535 | STATS_DECLTRACK_CSRET_ATTR(value_range){ static llvm::Statistic NumIRCSReturn_value_range = {"attributor" , "NumIRCSReturn_value_range", ("Number of " "call site returns" " marked '" "value_range" "'")};; ++(NumIRCSReturn_value_range ); } | |||
8536 | } | |||
8537 | }; | |||
8538 | struct AAValueConstantRangeCallSiteArgument : AAValueConstantRangeFloating { | |||
8539 | AAValueConstantRangeCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
8540 | : AAValueConstantRangeFloating(IRP, A) {} | |||
8541 | ||||
8542 | /// See AbstractAttribute::manifest() | |||
8543 | ChangeStatus manifest(Attributor &A) override { | |||
8544 | return ChangeStatus::UNCHANGED; | |||
8545 | } | |||
8546 | ||||
8547 | /// See AbstractAttribute::trackStatistics() | |||
8548 | void trackStatistics() const override { | |||
8549 | STATS_DECLTRACK_CSARG_ATTR(value_range){ static llvm::Statistic NumIRCSArguments_value_range = {"attributor" , "NumIRCSArguments_value_range", ("Number of " "call site arguments" " marked '" "value_range" "'")};; ++(NumIRCSArguments_value_range ); } | |||
8550 | } | |||
8551 | }; | |||
8552 | ||||
8553 | /// ------------------ Potential Values Attribute ------------------------- | |||
8554 | ||||
8555 | struct AAPotentialValuesImpl : AAPotentialValues { | |||
8556 | using StateType = PotentialConstantIntValuesState; | |||
8557 | ||||
8558 | AAPotentialValuesImpl(const IRPosition &IRP, Attributor &A) | |||
8559 | : AAPotentialValues(IRP, A) {} | |||
8560 | ||||
8561 | /// See AbstractAttribute::initialize(..). | |||
8562 | void initialize(Attributor &A) override { | |||
8563 | if (A.hasSimplificationCallback(getIRPosition())) | |||
8564 | indicatePessimisticFixpoint(); | |||
8565 | else | |||
8566 | AAPotentialValues::initialize(A); | |||
8567 | } | |||
8568 | ||||
8569 | /// See AbstractAttribute::getAsStr(). | |||
8570 | const std::string getAsStr() const override { | |||
8571 | std::string Str; | |||
8572 | llvm::raw_string_ostream OS(Str); | |||
8573 | OS << getState(); | |||
8574 | return OS.str(); | |||
8575 | } | |||
8576 | ||||
8577 | /// See AbstractAttribute::updateImpl(...). | |||
8578 | ChangeStatus updateImpl(Attributor &A) override { | |||
8579 | return indicatePessimisticFixpoint(); | |||
8580 | } | |||
8581 | }; | |||
8582 | ||||
8583 | struct AAPotentialValuesArgument final | |||
8584 | : AAArgumentFromCallSiteArguments<AAPotentialValues, AAPotentialValuesImpl, | |||
8585 | PotentialConstantIntValuesState> { | |||
8586 | using Base = | |||
8587 | AAArgumentFromCallSiteArguments<AAPotentialValues, AAPotentialValuesImpl, | |||
8588 | PotentialConstantIntValuesState>; | |||
8589 | AAPotentialValuesArgument(const IRPosition &IRP, Attributor &A) | |||
8590 | : Base(IRP, A) {} | |||
8591 | ||||
8592 | /// See AbstractAttribute::initialize(..). | |||
8593 | void initialize(Attributor &A) override { | |||
8594 | if (!getAnchorScope() || getAnchorScope()->isDeclaration()) { | |||
8595 | indicatePessimisticFixpoint(); | |||
8596 | } else { | |||
8597 | Base::initialize(A); | |||
8598 | } | |||
8599 | } | |||
8600 | ||||
8601 | /// See AbstractAttribute::trackStatistics() | |||
8602 | void trackStatistics() const override { | |||
8603 | STATS_DECLTRACK_ARG_ATTR(potential_values){ static llvm::Statistic NumIRArguments_potential_values = {"attributor" , "NumIRArguments_potential_values", ("Number of " "arguments" " marked '" "potential_values" "'")};; ++(NumIRArguments_potential_values ); } | |||
8604 | } | |||
8605 | }; | |||
8606 | ||||
8607 | struct AAPotentialValuesReturned | |||
8608 | : AAReturnedFromReturnedValues<AAPotentialValues, AAPotentialValuesImpl> { | |||
8609 | using Base = | |||
8610 | AAReturnedFromReturnedValues<AAPotentialValues, AAPotentialValuesImpl>; | |||
8611 | AAPotentialValuesReturned(const IRPosition &IRP, Attributor &A) | |||
8612 | : Base(IRP, A) {} | |||
8613 | ||||
8614 | /// See AbstractAttribute::trackStatistics() | |||
8615 | void trackStatistics() const override { | |||
8616 | STATS_DECLTRACK_FNRET_ATTR(potential_values){ static llvm::Statistic NumIRFunctionReturn_potential_values = {"attributor", "NumIRFunctionReturn_potential_values", ("Number of " "function returns" " marked '" "potential_values" "'")};; ++ (NumIRFunctionReturn_potential_values); } | |||
8617 | } | |||
8618 | }; | |||
8619 | ||||
8620 | struct AAPotentialValuesFloating : AAPotentialValuesImpl { | |||
8621 | AAPotentialValuesFloating(const IRPosition &IRP, Attributor &A) | |||
8622 | : AAPotentialValuesImpl(IRP, A) {} | |||
8623 | ||||
8624 | /// See AbstractAttribute::initialize(..). | |||
8625 | void initialize(Attributor &A) override { | |||
8626 | AAPotentialValuesImpl::initialize(A); | |||
8627 | if (isAtFixpoint()) | |||
8628 | return; | |||
8629 | ||||
8630 | Value &V = getAssociatedValue(); | |||
8631 | ||||
8632 | if (auto *C = dyn_cast<ConstantInt>(&V)) { | |||
8633 | unionAssumed(C->getValue()); | |||
8634 | indicateOptimisticFixpoint(); | |||
8635 | return; | |||
8636 | } | |||
8637 | ||||
8638 | if (isa<UndefValue>(&V)) { | |||
8639 | unionAssumedWithUndef(); | |||
8640 | indicateOptimisticFixpoint(); | |||
8641 | return; | |||
8642 | } | |||
8643 | ||||
8644 | if (isa<BinaryOperator>(&V) || isa<ICmpInst>(&V) || isa<CastInst>(&V)) | |||
8645 | return; | |||
8646 | ||||
8647 | if (isa<SelectInst>(V) || isa<PHINode>(V) || isa<LoadInst>(V)) | |||
8648 | return; | |||
8649 | ||||
8650 | indicatePessimisticFixpoint(); | |||
8651 | ||||
8652 | LLVM_DEBUG(dbgs() << "[AAPotentialValues] We give up: "do { } while (false) | |||
8653 | << getAssociatedValue() << "\n")do { } while (false); | |||
8654 | } | |||
8655 | ||||
8656 | static bool calculateICmpInst(const ICmpInst *ICI, const APInt &LHS, | |||
8657 | const APInt &RHS) { | |||
8658 | ICmpInst::Predicate Pred = ICI->getPredicate(); | |||
8659 | switch (Pred) { | |||
8660 | case ICmpInst::ICMP_UGT: | |||
8661 | return LHS.ugt(RHS); | |||
8662 | case ICmpInst::ICMP_SGT: | |||
8663 | return LHS.sgt(RHS); | |||
8664 | case ICmpInst::ICMP_EQ: | |||
8665 | return LHS.eq(RHS); | |||
8666 | case ICmpInst::ICMP_UGE: | |||
8667 | return LHS.uge(RHS); | |||
8668 | case ICmpInst::ICMP_SGE: | |||
8669 | return LHS.sge(RHS); | |||
8670 | case ICmpInst::ICMP_ULT: | |||
8671 | return LHS.ult(RHS); | |||
8672 | case ICmpInst::ICMP_SLT: | |||
8673 | return LHS.slt(RHS); | |||
8674 | case ICmpInst::ICMP_NE: | |||
8675 | return LHS.ne(RHS); | |||
8676 | case ICmpInst::ICMP_ULE: | |||
8677 | return LHS.ule(RHS); | |||
8678 | case ICmpInst::ICMP_SLE: | |||
8679 | return LHS.sle(RHS); | |||
8680 | default: | |||
8681 | llvm_unreachable("Invalid ICmp predicate!")__builtin_unreachable(); | |||
8682 | } | |||
8683 | } | |||
8684 | ||||
8685 | static APInt calculateCastInst(const CastInst *CI, const APInt &Src, | |||
8686 | uint32_t ResultBitWidth) { | |||
8687 | Instruction::CastOps CastOp = CI->getOpcode(); | |||
8688 | switch (CastOp) { | |||
8689 | default: | |||
8690 | llvm_unreachable("unsupported or not integer cast")__builtin_unreachable(); | |||
8691 | case Instruction::Trunc: | |||
8692 | return Src.trunc(ResultBitWidth); | |||
8693 | case Instruction::SExt: | |||
8694 | return Src.sext(ResultBitWidth); | |||
8695 | case Instruction::ZExt: | |||
8696 | return Src.zext(ResultBitWidth); | |||
8697 | case Instruction::BitCast: | |||
8698 | return Src; | |||
8699 | } | |||
8700 | } | |||
8701 | ||||
8702 | static APInt calculateBinaryOperator(const BinaryOperator *BinOp, | |||
8703 | const APInt &LHS, const APInt &RHS, | |||
8704 | bool &SkipOperation, bool &Unsupported) { | |||
8705 | Instruction::BinaryOps BinOpcode = BinOp->getOpcode(); | |||
8706 | // Unsupported is set to true when the binary operator is not supported. | |||
8707 | // SkipOperation is set to true when UB occur with the given operand pair | |||
8708 | // (LHS, RHS). | |||
8709 | // TODO: we should look at nsw and nuw keywords to handle operations | |||
8710 | // that create poison or undef value. | |||
8711 | switch (BinOpcode) { | |||
8712 | default: | |||
8713 | Unsupported = true; | |||
8714 | return LHS; | |||
8715 | case Instruction::Add: | |||
8716 | return LHS + RHS; | |||
8717 | case Instruction::Sub: | |||
8718 | return LHS - RHS; | |||
8719 | case Instruction::Mul: | |||
8720 | return LHS * RHS; | |||
8721 | case Instruction::UDiv: | |||
8722 | if (RHS.isNullValue()) { | |||
8723 | SkipOperation = true; | |||
8724 | return LHS; | |||
8725 | } | |||
8726 | return LHS.udiv(RHS); | |||
8727 | case Instruction::SDiv: | |||
8728 | if (RHS.isNullValue()) { | |||
8729 | SkipOperation = true; | |||
8730 | return LHS; | |||
8731 | } | |||
8732 | return LHS.sdiv(RHS); | |||
8733 | case Instruction::URem: | |||
8734 | if (RHS.isNullValue()) { | |||
8735 | SkipOperation = true; | |||
8736 | return LHS; | |||
8737 | } | |||
8738 | return LHS.urem(RHS); | |||
8739 | case Instruction::SRem: | |||
8740 | if (RHS.isNullValue()) { | |||
8741 | SkipOperation = true; | |||
8742 | return LHS; | |||
8743 | } | |||
8744 | return LHS.srem(RHS); | |||
8745 | case Instruction::Shl: | |||
8746 | return LHS.shl(RHS); | |||
8747 | case Instruction::LShr: | |||
8748 | return LHS.lshr(RHS); | |||
8749 | case Instruction::AShr: | |||
8750 | return LHS.ashr(RHS); | |||
8751 | case Instruction::And: | |||
8752 | return LHS & RHS; | |||
8753 | case Instruction::Or: | |||
8754 | return LHS | RHS; | |||
8755 | case Instruction::Xor: | |||
8756 | return LHS ^ RHS; | |||
8757 | } | |||
8758 | } | |||
8759 | ||||
8760 | bool calculateBinaryOperatorAndTakeUnion(const BinaryOperator *BinOp, | |||
8761 | const APInt &LHS, const APInt &RHS) { | |||
8762 | bool SkipOperation = false; | |||
8763 | bool Unsupported = false; | |||
8764 | APInt Result = | |||
8765 | calculateBinaryOperator(BinOp, LHS, RHS, SkipOperation, Unsupported); | |||
8766 | if (Unsupported) | |||
8767 | return false; | |||
8768 | // If SkipOperation is true, we can ignore this operand pair (L, R). | |||
8769 | if (!SkipOperation) | |||
8770 | unionAssumed(Result); | |||
8771 | return isValidState(); | |||
8772 | } | |||
8773 | ||||
8774 | ChangeStatus updateWithICmpInst(Attributor &A, ICmpInst *ICI) { | |||
8775 | auto AssumedBefore = getAssumed(); | |||
8776 | Value *LHS = ICI->getOperand(0); | |||
8777 | Value *RHS = ICI->getOperand(1); | |||
8778 | ||||
8779 | // Simplify the operands first. | |||
8780 | bool UsedAssumedInformation = false; | |||
8781 | const auto &SimplifiedLHS = | |||
8782 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), | |||
8783 | *this, UsedAssumedInformation); | |||
8784 | if (!SimplifiedLHS.hasValue()) | |||
8785 | return ChangeStatus::UNCHANGED; | |||
8786 | if (!SimplifiedLHS.getValue()) | |||
8787 | return indicatePessimisticFixpoint(); | |||
8788 | LHS = *SimplifiedLHS; | |||
8789 | ||||
8790 | const auto &SimplifiedRHS = | |||
8791 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), | |||
8792 | *this, UsedAssumedInformation); | |||
8793 | if (!SimplifiedRHS.hasValue()) | |||
8794 | return ChangeStatus::UNCHANGED; | |||
8795 | if (!SimplifiedRHS.getValue()) | |||
8796 | return indicatePessimisticFixpoint(); | |||
8797 | RHS = *SimplifiedRHS; | |||
8798 | ||||
8799 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) | |||
8800 | return indicatePessimisticFixpoint(); | |||
8801 | ||||
8802 | auto &LHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*LHS), | |||
8803 | DepClassTy::REQUIRED); | |||
8804 | if (!LHSAA.isValidState()) | |||
8805 | return indicatePessimisticFixpoint(); | |||
8806 | ||||
8807 | auto &RHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*RHS), | |||
8808 | DepClassTy::REQUIRED); | |||
8809 | if (!RHSAA.isValidState()) | |||
8810 | return indicatePessimisticFixpoint(); | |||
8811 | ||||
8812 | const DenseSet<APInt> &LHSAAPVS = LHSAA.getAssumedSet(); | |||
8813 | const DenseSet<APInt> &RHSAAPVS = RHSAA.getAssumedSet(); | |||
8814 | ||||
8815 | // TODO: make use of undef flag to limit potential values aggressively. | |||
8816 | bool MaybeTrue = false, MaybeFalse = false; | |||
8817 | const APInt Zero(RHS->getType()->getIntegerBitWidth(), 0); | |||
8818 | if (LHSAA.undefIsContained() && RHSAA.undefIsContained()) { | |||
8819 | // The result of any comparison between undefs can be soundly replaced | |||
8820 | // with undef. | |||
8821 | unionAssumedWithUndef(); | |||
8822 | } else if (LHSAA.undefIsContained()) { | |||
8823 | for (const APInt &R : RHSAAPVS) { | |||
8824 | bool CmpResult = calculateICmpInst(ICI, Zero, R); | |||
8825 | MaybeTrue |= CmpResult; | |||
8826 | MaybeFalse |= !CmpResult; | |||
8827 | if (MaybeTrue & MaybeFalse) | |||
8828 | return indicatePessimisticFixpoint(); | |||
8829 | } | |||
8830 | } else if (RHSAA.undefIsContained()) { | |||
8831 | for (const APInt &L : LHSAAPVS) { | |||
8832 | bool CmpResult = calculateICmpInst(ICI, L, Zero); | |||
8833 | MaybeTrue |= CmpResult; | |||
8834 | MaybeFalse |= !CmpResult; | |||
8835 | if (MaybeTrue & MaybeFalse) | |||
8836 | return indicatePessimisticFixpoint(); | |||
8837 | } | |||
8838 | } else { | |||
8839 | for (const APInt &L : LHSAAPVS) { | |||
8840 | for (const APInt &R : RHSAAPVS) { | |||
8841 | bool CmpResult = calculateICmpInst(ICI, L, R); | |||
8842 | MaybeTrue |= CmpResult; | |||
8843 | MaybeFalse |= !CmpResult; | |||
8844 | if (MaybeTrue & MaybeFalse) | |||
8845 | return indicatePessimisticFixpoint(); | |||
8846 | } | |||
8847 | } | |||
8848 | } | |||
8849 | if (MaybeTrue) | |||
8850 | unionAssumed(APInt(/* numBits */ 1, /* val */ 1)); | |||
8851 | if (MaybeFalse) | |||
8852 | unionAssumed(APInt(/* numBits */ 1, /* val */ 0)); | |||
8853 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED | |||
8854 | : ChangeStatus::CHANGED; | |||
8855 | } | |||
8856 | ||||
8857 | ChangeStatus updateWithSelectInst(Attributor &A, SelectInst *SI) { | |||
8858 | auto AssumedBefore = getAssumed(); | |||
8859 | Value *LHS = SI->getTrueValue(); | |||
8860 | Value *RHS = SI->getFalseValue(); | |||
8861 | ||||
8862 | // Simplify the operands first. | |||
8863 | bool UsedAssumedInformation = false; | |||
8864 | const auto &SimplifiedLHS = | |||
8865 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), | |||
8866 | *this, UsedAssumedInformation); | |||
8867 | if (!SimplifiedLHS.hasValue()) | |||
8868 | return ChangeStatus::UNCHANGED; | |||
8869 | if (!SimplifiedLHS.getValue()) | |||
8870 | return indicatePessimisticFixpoint(); | |||
8871 | LHS = *SimplifiedLHS; | |||
8872 | ||||
8873 | const auto &SimplifiedRHS = | |||
8874 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), | |||
8875 | *this, UsedAssumedInformation); | |||
8876 | if (!SimplifiedRHS.hasValue()) | |||
8877 | return ChangeStatus::UNCHANGED; | |||
8878 | if (!SimplifiedRHS.getValue()) | |||
8879 | return indicatePessimisticFixpoint(); | |||
8880 | RHS = *SimplifiedRHS; | |||
8881 | ||||
8882 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) | |||
8883 | return indicatePessimisticFixpoint(); | |||
8884 | ||||
8885 | Optional<Constant *> C = A.getAssumedConstant(*SI->getCondition(), *this, | |||
8886 | UsedAssumedInformation); | |||
8887 | ||||
8888 | // Check if we only need one operand. | |||
8889 | bool OnlyLeft = false, OnlyRight = false; | |||
8890 | if (C.hasValue() && *C && (*C)->isOneValue()) | |||
8891 | OnlyLeft = true; | |||
8892 | else if (C.hasValue() && *C && (*C)->isZeroValue()) | |||
8893 | OnlyRight = true; | |||
8894 | ||||
8895 | const AAPotentialValues *LHSAA = nullptr, *RHSAA = nullptr; | |||
8896 | if (!OnlyRight) { | |||
8897 | LHSAA = &A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*LHS), | |||
8898 | DepClassTy::REQUIRED); | |||
8899 | if (!LHSAA->isValidState()) | |||
8900 | return indicatePessimisticFixpoint(); | |||
8901 | } | |||
8902 | if (!OnlyLeft) { | |||
8903 | RHSAA = &A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*RHS), | |||
8904 | DepClassTy::REQUIRED); | |||
8905 | if (!RHSAA->isValidState()) | |||
8906 | return indicatePessimisticFixpoint(); | |||
8907 | } | |||
8908 | ||||
8909 | if (!LHSAA || !RHSAA) { | |||
8910 | // select (true/false), lhs, rhs | |||
8911 | auto *OpAA = LHSAA ? LHSAA : RHSAA; | |||
8912 | ||||
8913 | if (OpAA->undefIsContained()) | |||
8914 | unionAssumedWithUndef(); | |||
8915 | else | |||
8916 | unionAssumed(*OpAA); | |||
8917 | ||||
8918 | } else if (LHSAA->undefIsContained() && RHSAA->undefIsContained()) { | |||
8919 | // select i1 *, undef , undef => undef | |||
8920 | unionAssumedWithUndef(); | |||
8921 | } else { | |||
8922 | unionAssumed(*LHSAA); | |||
8923 | unionAssumed(*RHSAA); | |||
8924 | } | |||
8925 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED | |||
8926 | : ChangeStatus::CHANGED; | |||
8927 | } | |||
8928 | ||||
8929 | ChangeStatus updateWithCastInst(Attributor &A, CastInst *CI) { | |||
8930 | auto AssumedBefore = getAssumed(); | |||
8931 | if (!CI->isIntegerCast()) | |||
8932 | return indicatePessimisticFixpoint(); | |||
8933 | assert(CI->getNumOperands() == 1 && "Expected cast to be unary!")((void)0); | |||
8934 | uint32_t ResultBitWidth = CI->getDestTy()->getIntegerBitWidth(); | |||
8935 | Value *Src = CI->getOperand(0); | |||
8936 | ||||
8937 | // Simplify the operand first. | |||
8938 | bool UsedAssumedInformation = false; | |||
8939 | const auto &SimplifiedSrc = | |||
8940 | A.getAssumedSimplified(IRPosition::value(*Src, getCallBaseContext()), | |||
8941 | *this, UsedAssumedInformation); | |||
8942 | if (!SimplifiedSrc.hasValue()) | |||
8943 | return ChangeStatus::UNCHANGED; | |||
8944 | if (!SimplifiedSrc.getValue()) | |||
8945 | return indicatePessimisticFixpoint(); | |||
8946 | Src = *SimplifiedSrc; | |||
8947 | ||||
8948 | auto &SrcAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*Src), | |||
8949 | DepClassTy::REQUIRED); | |||
8950 | if (!SrcAA.isValidState()) | |||
8951 | return indicatePessimisticFixpoint(); | |||
8952 | const DenseSet<APInt> &SrcAAPVS = SrcAA.getAssumedSet(); | |||
8953 | if (SrcAA.undefIsContained()) | |||
8954 | unionAssumedWithUndef(); | |||
8955 | else { | |||
8956 | for (const APInt &S : SrcAAPVS) { | |||
8957 | APInt T = calculateCastInst(CI, S, ResultBitWidth); | |||
8958 | unionAssumed(T); | |||
8959 | } | |||
8960 | } | |||
8961 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED | |||
8962 | : ChangeStatus::CHANGED; | |||
8963 | } | |||
8964 | ||||
8965 | ChangeStatus updateWithBinaryOperator(Attributor &A, BinaryOperator *BinOp) { | |||
8966 | auto AssumedBefore = getAssumed(); | |||
8967 | Value *LHS = BinOp->getOperand(0); | |||
8968 | Value *RHS = BinOp->getOperand(1); | |||
8969 | ||||
8970 | // Simplify the operands first. | |||
8971 | bool UsedAssumedInformation = false; | |||
8972 | const auto &SimplifiedLHS = | |||
8973 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), | |||
8974 | *this, UsedAssumedInformation); | |||
8975 | if (!SimplifiedLHS.hasValue()) | |||
8976 | return ChangeStatus::UNCHANGED; | |||
8977 | if (!SimplifiedLHS.getValue()) | |||
8978 | return indicatePessimisticFixpoint(); | |||
8979 | LHS = *SimplifiedLHS; | |||
8980 | ||||
8981 | const auto &SimplifiedRHS = | |||
8982 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), | |||
8983 | *this, UsedAssumedInformation); | |||
8984 | if (!SimplifiedRHS.hasValue()) | |||
8985 | return ChangeStatus::UNCHANGED; | |||
8986 | if (!SimplifiedRHS.getValue()) | |||
8987 | return indicatePessimisticFixpoint(); | |||
8988 | RHS = *SimplifiedRHS; | |||
8989 | ||||
8990 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) | |||
8991 | return indicatePessimisticFixpoint(); | |||
8992 | ||||
8993 | auto &LHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*LHS), | |||
8994 | DepClassTy::REQUIRED); | |||
8995 | if (!LHSAA.isValidState()) | |||
8996 | return indicatePessimisticFixpoint(); | |||
8997 | ||||
8998 | auto &RHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*RHS), | |||
8999 | DepClassTy::REQUIRED); | |||
9000 | if (!RHSAA.isValidState()) | |||
9001 | return indicatePessimisticFixpoint(); | |||
9002 | ||||
9003 | const DenseSet<APInt> &LHSAAPVS = LHSAA.getAssumedSet(); | |||
9004 | const DenseSet<APInt> &RHSAAPVS = RHSAA.getAssumedSet(); | |||
9005 | const APInt Zero = APInt(LHS->getType()->getIntegerBitWidth(), 0); | |||
9006 | ||||
9007 | // TODO: make use of undef flag to limit potential values aggressively. | |||
9008 | if (LHSAA.undefIsContained() && RHSAA.undefIsContained()) { | |||
9009 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, Zero, Zero)) | |||
9010 | return indicatePessimisticFixpoint(); | |||
9011 | } else if (LHSAA.undefIsContained()) { | |||
9012 | for (const APInt &R : RHSAAPVS) { | |||
9013 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, Zero, R)) | |||
9014 | return indicatePessimisticFixpoint(); | |||
9015 | } | |||
9016 | } else if (RHSAA.undefIsContained()) { | |||
9017 | for (const APInt &L : LHSAAPVS) { | |||
9018 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, L, Zero)) | |||
9019 | return indicatePessimisticFixpoint(); | |||
9020 | } | |||
9021 | } else { | |||
9022 | for (const APInt &L : LHSAAPVS) { | |||
9023 | for (const APInt &R : RHSAAPVS) { | |||
9024 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, L, R)) | |||
9025 | return indicatePessimisticFixpoint(); | |||
9026 | } | |||
9027 | } | |||
9028 | } | |||
9029 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED | |||
9030 | : ChangeStatus::CHANGED; | |||
9031 | } | |||
9032 | ||||
9033 | ChangeStatus updateWithPHINode(Attributor &A, PHINode *PHI) { | |||
9034 | auto AssumedBefore = getAssumed(); | |||
9035 | for (unsigned u = 0, e = PHI->getNumIncomingValues(); u < e; u++) { | |||
9036 | Value *IncomingValue = PHI->getIncomingValue(u); | |||
9037 | ||||
9038 | // Simplify the operand first. | |||
9039 | bool UsedAssumedInformation = false; | |||
9040 | const auto &SimplifiedIncomingValue = A.getAssumedSimplified( | |||
9041 | IRPosition::value(*IncomingValue, getCallBaseContext()), *this, | |||
9042 | UsedAssumedInformation); | |||
9043 | if (!SimplifiedIncomingValue.hasValue()) | |||
9044 | continue; | |||
9045 | if (!SimplifiedIncomingValue.getValue()) | |||
9046 | return indicatePessimisticFixpoint(); | |||
9047 | IncomingValue = *SimplifiedIncomingValue; | |||
9048 | ||||
9049 | auto &PotentialValuesAA = A.getAAFor<AAPotentialValues>( | |||
9050 | *this, IRPosition::value(*IncomingValue), DepClassTy::REQUIRED); | |||
9051 | if (!PotentialValuesAA.isValidState()) | |||
9052 | return indicatePessimisticFixpoint(); | |||
9053 | if (PotentialValuesAA.undefIsContained()) | |||
9054 | unionAssumedWithUndef(); | |||
9055 | else | |||
9056 | unionAssumed(PotentialValuesAA.getAssumed()); | |||
9057 | } | |||
9058 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED | |||
9059 | : ChangeStatus::CHANGED; | |||
9060 | } | |||
9061 | ||||
9062 | ChangeStatus updateWithLoad(Attributor &A, LoadInst &L) { | |||
9063 | if (!L.getType()->isIntegerTy()) | |||
9064 | return indicatePessimisticFixpoint(); | |||
9065 | ||||
9066 | auto Union = [&](Value &V) { | |||
9067 | if (isa<UndefValue>(V)) { | |||
9068 | unionAssumedWithUndef(); | |||
9069 | return true; | |||
9070 | } | |||
9071 | if (ConstantInt *CI = dyn_cast<ConstantInt>(&V)) { | |||
9072 | unionAssumed(CI->getValue()); | |||
9073 | return true; | |||
9074 | } | |||
9075 | return false; | |||
9076 | }; | |||
9077 | auto AssumedBefore = getAssumed(); | |||
9078 | ||||
9079 | if (!AAValueSimplifyImpl::handleLoad(A, *this, L, Union)) | |||
9080 | return indicatePessimisticFixpoint(); | |||
9081 | ||||
9082 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED | |||
9083 | : ChangeStatus::CHANGED; | |||
9084 | } | |||
9085 | ||||
9086 | /// See AbstractAttribute::updateImpl(...). | |||
9087 | ChangeStatus updateImpl(Attributor &A) override { | |||
9088 | Value &V = getAssociatedValue(); | |||
9089 | Instruction *I = dyn_cast<Instruction>(&V); | |||
9090 | ||||
9091 | if (auto *ICI = dyn_cast<ICmpInst>(I)) | |||
9092 | return updateWithICmpInst(A, ICI); | |||
9093 | ||||
9094 | if (auto *SI = dyn_cast<SelectInst>(I)) | |||
9095 | return updateWithSelectInst(A, SI); | |||
9096 | ||||
9097 | if (auto *CI = dyn_cast<CastInst>(I)) | |||
9098 | return updateWithCastInst(A, CI); | |||
9099 | ||||
9100 | if (auto *BinOp = dyn_cast<BinaryOperator>(I)) | |||
9101 | return updateWithBinaryOperator(A, BinOp); | |||
9102 | ||||
9103 | if (auto *PHI = dyn_cast<PHINode>(I)) | |||
9104 | return updateWithPHINode(A, PHI); | |||
9105 | ||||
9106 | if (auto *L = dyn_cast<LoadInst>(I)) | |||
9107 | return updateWithLoad(A, *L); | |||
9108 | ||||
9109 | return indicatePessimisticFixpoint(); | |||
9110 | } | |||
9111 | ||||
9112 | /// See AbstractAttribute::trackStatistics() | |||
9113 | void trackStatistics() const override { | |||
9114 | STATS_DECLTRACK_FLOATING_ATTR(potential_values){ static llvm::Statistic NumIRFloating_potential_values = {"attributor" , "NumIRFloating_potential_values", ("Number of floating values known to be '" "potential_values" "'")};; ++(NumIRFloating_potential_values ); } | |||
9115 | } | |||
9116 | }; | |||
9117 | ||||
9118 | struct AAPotentialValuesFunction : AAPotentialValuesImpl { | |||
9119 | AAPotentialValuesFunction(const IRPosition &IRP, Attributor &A) | |||
9120 | : AAPotentialValuesImpl(IRP, A) {} | |||
9121 | ||||
9122 | /// See AbstractAttribute::initialize(...). | |||
9123 | ChangeStatus updateImpl(Attributor &A) override { | |||
9124 | llvm_unreachable("AAPotentialValues(Function|CallSite)::updateImpl will "__builtin_unreachable() | |||
9125 | "not be called")__builtin_unreachable(); | |||
9126 | } | |||
9127 | ||||
9128 | /// See AbstractAttribute::trackStatistics() | |||
9129 | void trackStatistics() const override { | |||
9130 | STATS_DECLTRACK_FN_ATTR(potential_values){ static llvm::Statistic NumIRFunction_potential_values = {"attributor" , "NumIRFunction_potential_values", ("Number of " "functions" " marked '" "potential_values" "'")};; ++(NumIRFunction_potential_values ); } | |||
9131 | } | |||
9132 | }; | |||
9133 | ||||
9134 | struct AAPotentialValuesCallSite : AAPotentialValuesFunction { | |||
9135 | AAPotentialValuesCallSite(const IRPosition &IRP, Attributor &A) | |||
9136 | : AAPotentialValuesFunction(IRP, A) {} | |||
9137 | ||||
9138 | /// See AbstractAttribute::trackStatistics() | |||
9139 | void trackStatistics() const override { | |||
9140 | STATS_DECLTRACK_CS_ATTR(potential_values){ static llvm::Statistic NumIRCS_potential_values = {"attributor" , "NumIRCS_potential_values", ("Number of " "call site" " marked '" "potential_values" "'")};; ++(NumIRCS_potential_values); } | |||
9141 | } | |||
9142 | }; | |||
9143 | ||||
9144 | struct AAPotentialValuesCallSiteReturned | |||
9145 | : AACallSiteReturnedFromReturned<AAPotentialValues, AAPotentialValuesImpl> { | |||
9146 | AAPotentialValuesCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
9147 | : AACallSiteReturnedFromReturned<AAPotentialValues, | |||
9148 | AAPotentialValuesImpl>(IRP, A) {} | |||
9149 | ||||
9150 | /// See AbstractAttribute::trackStatistics() | |||
9151 | void trackStatistics() const override { | |||
9152 | STATS_DECLTRACK_CSRET_ATTR(potential_values){ static llvm::Statistic NumIRCSReturn_potential_values = {"attributor" , "NumIRCSReturn_potential_values", ("Number of " "call site returns" " marked '" "potential_values" "'")};; ++(NumIRCSReturn_potential_values ); } | |||
9153 | } | |||
9154 | }; | |||
9155 | ||||
9156 | struct AAPotentialValuesCallSiteArgument : AAPotentialValuesFloating { | |||
9157 | AAPotentialValuesCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
9158 | : AAPotentialValuesFloating(IRP, A) {} | |||
9159 | ||||
9160 | /// See AbstractAttribute::initialize(..). | |||
9161 | void initialize(Attributor &A) override { | |||
9162 | AAPotentialValuesImpl::initialize(A); | |||
9163 | if (isAtFixpoint()) | |||
9164 | return; | |||
9165 | ||||
9166 | Value &V = getAssociatedValue(); | |||
9167 | ||||
9168 | if (auto *C = dyn_cast<ConstantInt>(&V)) { | |||
9169 | unionAssumed(C->getValue()); | |||
9170 | indicateOptimisticFixpoint(); | |||
9171 | return; | |||
9172 | } | |||
9173 | ||||
9174 | if (isa<UndefValue>(&V)) { | |||
9175 | unionAssumedWithUndef(); | |||
9176 | indicateOptimisticFixpoint(); | |||
9177 | return; | |||
9178 | } | |||
9179 | } | |||
9180 | ||||
9181 | /// See AbstractAttribute::updateImpl(...). | |||
9182 | ChangeStatus updateImpl(Attributor &A) override { | |||
9183 | Value &V = getAssociatedValue(); | |||
9184 | auto AssumedBefore = getAssumed(); | |||
9185 | auto &AA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(V), | |||
9186 | DepClassTy::REQUIRED); | |||
9187 | const auto &S = AA.getAssumed(); | |||
9188 | unionAssumed(S); | |||
9189 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED | |||
9190 | : ChangeStatus::CHANGED; | |||
9191 | } | |||
9192 | ||||
9193 | /// See AbstractAttribute::trackStatistics() | |||
9194 | void trackStatistics() const override { | |||
9195 | STATS_DECLTRACK_CSARG_ATTR(potential_values){ static llvm::Statistic NumIRCSArguments_potential_values = { "attributor", "NumIRCSArguments_potential_values", ("Number of " "call site arguments" " marked '" "potential_values" "'")};; ++(NumIRCSArguments_potential_values); } | |||
9196 | } | |||
9197 | }; | |||
9198 | ||||
9199 | /// ------------------------ NoUndef Attribute --------------------------------- | |||
9200 | struct AANoUndefImpl : AANoUndef { | |||
9201 | AANoUndefImpl(const IRPosition &IRP, Attributor &A) : AANoUndef(IRP, A) {} | |||
9202 | ||||
9203 | /// See AbstractAttribute::initialize(...). | |||
9204 | void initialize(Attributor &A) override { | |||
9205 | if (getIRPosition().hasAttr({Attribute::NoUndef})) { | |||
9206 | indicateOptimisticFixpoint(); | |||
9207 | return; | |||
9208 | } | |||
9209 | Value &V = getAssociatedValue(); | |||
9210 | if (isa<UndefValue>(V)) | |||
9211 | indicatePessimisticFixpoint(); | |||
9212 | else if (isa<FreezeInst>(V)) | |||
9213 | indicateOptimisticFixpoint(); | |||
9214 | else if (getPositionKind() != IRPosition::IRP_RETURNED && | |||
9215 | isGuaranteedNotToBeUndefOrPoison(&V)) | |||
9216 | indicateOptimisticFixpoint(); | |||
9217 | else | |||
9218 | AANoUndef::initialize(A); | |||
9219 | } | |||
9220 | ||||
9221 | /// See followUsesInMBEC | |||
9222 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, | |||
9223 | AANoUndef::StateType &State) { | |||
9224 | const Value *UseV = U->get(); | |||
9225 | const DominatorTree *DT = nullptr; | |||
9226 | AssumptionCache *AC = nullptr; | |||
9227 | InformationCache &InfoCache = A.getInfoCache(); | |||
9228 | if (Function *F = getAnchorScope()) { | |||
9229 | DT = InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>(*F); | |||
9230 | AC = InfoCache.getAnalysisResultForFunction<AssumptionAnalysis>(*F); | |||
9231 | } | |||
9232 | State.setKnown(isGuaranteedNotToBeUndefOrPoison(UseV, AC, I, DT)); | |||
9233 | bool TrackUse = false; | |||
9234 | // Track use for instructions which must produce undef or poison bits when | |||
9235 | // at least one operand contains such bits. | |||
9236 | if (isa<CastInst>(*I) || isa<GetElementPtrInst>(*I)) | |||
9237 | TrackUse = true; | |||
9238 | return TrackUse; | |||
9239 | } | |||
9240 | ||||
9241 | /// See AbstractAttribute::getAsStr(). | |||
9242 | const std::string getAsStr() const override { | |||
9243 | return getAssumed() ? "noundef" : "may-undef-or-poison"; | |||
9244 | } | |||
9245 | ||||
9246 | ChangeStatus manifest(Attributor &A) override { | |||
9247 | // We don't manifest noundef attribute for dead positions because the | |||
9248 | // associated values with dead positions would be replaced with undef | |||
9249 | // values. | |||
9250 | bool UsedAssumedInformation = false; | |||
9251 | if (A.isAssumedDead(getIRPosition(), nullptr, nullptr, | |||
9252 | UsedAssumedInformation)) | |||
9253 | return ChangeStatus::UNCHANGED; | |||
9254 | // A position whose simplified value does not have any value is | |||
9255 | // considered to be dead. We don't manifest noundef in such positions for | |||
9256 | // the same reason above. | |||
9257 | if (!A.getAssumedSimplified(getIRPosition(), *this, UsedAssumedInformation) | |||
9258 | .hasValue()) | |||
9259 | return ChangeStatus::UNCHANGED; | |||
9260 | return AANoUndef::manifest(A); | |||
9261 | } | |||
9262 | }; | |||
9263 | ||||
9264 | struct AANoUndefFloating : public AANoUndefImpl { | |||
9265 | AANoUndefFloating(const IRPosition &IRP, Attributor &A) | |||
9266 | : AANoUndefImpl(IRP, A) {} | |||
9267 | ||||
9268 | /// See AbstractAttribute::initialize(...). | |||
9269 | void initialize(Attributor &A) override { | |||
9270 | AANoUndefImpl::initialize(A); | |||
9271 | if (!getState().isAtFixpoint()) | |||
9272 | if (Instruction *CtxI = getCtxI()) | |||
9273 | followUsesInMBEC(*this, A, getState(), *CtxI); | |||
9274 | } | |||
9275 | ||||
9276 | /// See AbstractAttribute::updateImpl(...). | |||
9277 | ChangeStatus updateImpl(Attributor &A) override { | |||
9278 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, | |||
9279 | AANoUndef::StateType &T, bool Stripped) -> bool { | |||
9280 | const auto &AA = A.getAAFor<AANoUndef>(*this, IRPosition::value(V), | |||
9281 | DepClassTy::REQUIRED); | |||
9282 | if (!Stripped && this == &AA) { | |||
9283 | T.indicatePessimisticFixpoint(); | |||
9284 | } else { | |||
9285 | const AANoUndef::StateType &S = | |||
9286 | static_cast<const AANoUndef::StateType &>(AA.getState()); | |||
9287 | T ^= S; | |||
9288 | } | |||
9289 | return T.isValidState(); | |||
9290 | }; | |||
9291 | ||||
9292 | StateType T; | |||
9293 | if (!genericValueTraversal<StateType>(A, getIRPosition(), *this, T, | |||
9294 | VisitValueCB, getCtxI())) | |||
9295 | return indicatePessimisticFixpoint(); | |||
9296 | ||||
9297 | return clampStateAndIndicateChange(getState(), T); | |||
9298 | } | |||
9299 | ||||
9300 | /// See AbstractAttribute::trackStatistics() | |||
9301 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(noundef){ static llvm::Statistic NumIRFunctionReturn_noundef = {"attributor" , "NumIRFunctionReturn_noundef", ("Number of " "function returns" " marked '" "noundef" "'")};; ++(NumIRFunctionReturn_noundef ); } } | |||
9302 | }; | |||
9303 | ||||
9304 | struct AANoUndefReturned final | |||
9305 | : AAReturnedFromReturnedValues<AANoUndef, AANoUndefImpl> { | |||
9306 | AANoUndefReturned(const IRPosition &IRP, Attributor &A) | |||
9307 | : AAReturnedFromReturnedValues<AANoUndef, AANoUndefImpl>(IRP, A) {} | |||
9308 | ||||
9309 | /// See AbstractAttribute::trackStatistics() | |||
9310 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(noundef){ static llvm::Statistic NumIRFunctionReturn_noundef = {"attributor" , "NumIRFunctionReturn_noundef", ("Number of " "function returns" " marked '" "noundef" "'")};; ++(NumIRFunctionReturn_noundef ); } } | |||
9311 | }; | |||
9312 | ||||
9313 | struct AANoUndefArgument final | |||
9314 | : AAArgumentFromCallSiteArguments<AANoUndef, AANoUndefImpl> { | |||
9315 | AANoUndefArgument(const IRPosition &IRP, Attributor &A) | |||
9316 | : AAArgumentFromCallSiteArguments<AANoUndef, AANoUndefImpl>(IRP, A) {} | |||
9317 | ||||
9318 | /// See AbstractAttribute::trackStatistics() | |||
9319 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(noundef){ static llvm::Statistic NumIRArguments_noundef = {"attributor" , "NumIRArguments_noundef", ("Number of " "arguments" " marked '" "noundef" "'")};; ++(NumIRArguments_noundef); } } | |||
9320 | }; | |||
9321 | ||||
9322 | struct AANoUndefCallSiteArgument final : AANoUndefFloating { | |||
9323 | AANoUndefCallSiteArgument(const IRPosition &IRP, Attributor &A) | |||
9324 | : AANoUndefFloating(IRP, A) {} | |||
9325 | ||||
9326 | /// See AbstractAttribute::trackStatistics() | |||
9327 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(noundef){ static llvm::Statistic NumIRCSArguments_noundef = {"attributor" , "NumIRCSArguments_noundef", ("Number of " "call site arguments" " marked '" "noundef" "'")};; ++(NumIRCSArguments_noundef); } } | |||
9328 | }; | |||
9329 | ||||
9330 | struct AANoUndefCallSiteReturned final | |||
9331 | : AACallSiteReturnedFromReturned<AANoUndef, AANoUndefImpl> { | |||
9332 | AANoUndefCallSiteReturned(const IRPosition &IRP, Attributor &A) | |||
9333 | : AACallSiteReturnedFromReturned<AANoUndef, AANoUndefImpl>(IRP, A) {} | |||
9334 | ||||
9335 | /// See AbstractAttribute::trackStatistics() | |||
9336 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(noundef){ static llvm::Statistic NumIRCSReturn_noundef = {"attributor" , "NumIRCSReturn_noundef", ("Number of " "call site returns" " marked '" "noundef" "'")};; ++(NumIRCSReturn_noundef); } } | |||
9337 | }; | |||
9338 | ||||
9339 | struct AACallEdgesFunction : public AACallEdges { | |||
9340 | AACallEdgesFunction(const IRPosition &IRP, Attributor &A) | |||
9341 | : AACallEdges(IRP, A) {} | |||
9342 | ||||
9343 | /// See AbstractAttribute::updateImpl(...). | |||
9344 | ChangeStatus updateImpl(Attributor &A) override { | |||
9345 | ChangeStatus Change = ChangeStatus::UNCHANGED; | |||
9346 | bool OldHasUnknownCallee = HasUnknownCallee; | |||
9347 | bool OldHasUnknownCalleeNonAsm = HasUnknownCalleeNonAsm; | |||
9348 | ||||
9349 | auto AddCalledFunction = [&](Function *Fn) { | |||
9350 | if (CalledFunctions.insert(Fn)) { | |||
9351 | Change = ChangeStatus::CHANGED; | |||
9352 | LLVM_DEBUG(dbgs() << "[AACallEdges] New call edge: " << Fn->getName()do { } while (false) | |||
9353 | << "\n")do { } while (false); | |||
9354 | } | |||
9355 | }; | |||
9356 | ||||
9357 | auto VisitValue = [&](Value &V, const Instruction *CtxI, bool &HasUnknown, | |||
9358 | bool Stripped) -> bool { | |||
9359 | if (Function *Fn = dyn_cast<Function>(&V)) { | |||
9360 | AddCalledFunction(Fn); | |||
9361 | } else { | |||
9362 | LLVM_DEBUG(dbgs() << "[AACallEdges] Unrecognized value: " << V << "\n")do { } while (false); | |||
9363 | HasUnknown = true; | |||
9364 | HasUnknownCalleeNonAsm = true; | |||
9365 | } | |||
9366 | ||||
9367 | // Explore all values. | |||
9368 | return true; | |||
9369 | }; | |||
9370 | ||||
9371 | // Process any value that we might call. | |||
9372 | auto ProcessCalledOperand = [&](Value *V, Instruction *Ctx) { | |||
9373 | if (!genericValueTraversal<bool>(A, IRPosition::value(*V), *this, | |||
9374 | HasUnknownCallee, VisitValue, nullptr, | |||
9375 | false)) { | |||
9376 | // If we haven't gone through all values, assume that there are unknown | |||
9377 | // callees. | |||
9378 | HasUnknownCallee = true; | |||
9379 | HasUnknownCalleeNonAsm = true; | |||
9380 | } | |||
9381 | }; | |||
9382 | ||||
9383 | auto ProcessCallInst = [&](Instruction &Inst) { | |||
9384 | CallBase &CB = static_cast<CallBase &>(Inst); | |||
9385 | if (CB.isInlineAsm()) { | |||
9386 | HasUnknownCallee = true; | |||
9387 | return true; | |||
9388 | } | |||
9389 | ||||
9390 | // Process callee metadata if available. | |||
9391 | if (auto *MD = Inst.getMetadata(LLVMContext::MD_callees)) { | |||
9392 | for (auto &Op : MD->operands()) { | |||
9393 | Function *Callee = mdconst::extract_or_null<Function>(Op); | |||
9394 | if (Callee) | |||
9395 | AddCalledFunction(Callee); | |||
9396 | } | |||
9397 | // Callees metadata grantees that the called function is one of its | |||
9398 | // operands, So we are done. | |||
9399 | return true; | |||
9400 | } | |||
9401 | ||||
9402 | // The most simple case. | |||
9403 | ProcessCalledOperand(CB.getCalledOperand(), &Inst); | |||
9404 | ||||
9405 | // Process callback functions. | |||
9406 | SmallVector<const Use *, 4u> CallbackUses; | |||
9407 | AbstractCallSite::getCallbackUses(CB, CallbackUses); | |||
9408 | for (const Use *U : CallbackUses) | |||
9409 | ProcessCalledOperand(U->get(), &Inst); | |||
9410 | ||||
9411 | return true; | |||
9412 | }; | |||
9413 | ||||
9414 | // Visit all callable instructions. | |||
9415 | bool UsedAssumedInformation = false; | |||
9416 | if (!A.checkForAllCallLikeInstructions(ProcessCallInst, *this, | |||
9417 | UsedAssumedInformation)) { | |||
9418 | // If we haven't looked at all call like instructions, assume that there | |||
9419 | // are unknown callees. | |||
9420 | HasUnknownCallee = true; | |||
9421 | HasUnknownCalleeNonAsm = true; | |||
9422 | } | |||
9423 | ||||
9424 | // Track changes. | |||
9425 | if (OldHasUnknownCallee != HasUnknownCallee || | |||
9426 | OldHasUnknownCalleeNonAsm != HasUnknownCalleeNonAsm) | |||
9427 | Change = ChangeStatus::CHANGED; | |||
9428 | ||||
9429 | return Change; | |||
9430 | } | |||
9431 | ||||
9432 | virtual const SetVector<Function *> &getOptimisticEdges() const override { | |||
9433 | return CalledFunctions; | |||
9434 | }; | |||
9435 | ||||
9436 | virtual bool hasUnknownCallee() const override { return HasUnknownCallee; } | |||
9437 | ||||
9438 | virtual bool hasNonAsmUnknownCallee() const override { | |||
9439 | return HasUnknownCalleeNonAsm; | |||
9440 | } | |||
9441 | ||||
9442 | const std::string getAsStr() const override { | |||
9443 | return "CallEdges[" + std::to_string(HasUnknownCallee) + "," + | |||
9444 | std::to_string(CalledFunctions.size()) + "]"; | |||
9445 | } | |||
9446 | ||||
9447 | void trackStatistics() const override {} | |||
9448 | ||||
9449 | /// Optimistic set of functions that might be called by this function. | |||
9450 | SetVector<Function *> CalledFunctions; | |||
9451 | ||||
9452 | /// Is there any call with a unknown callee. | |||
9453 | bool HasUnknownCallee = false; | |||
9454 | ||||
9455 | /// Is there any call with a unknown callee, excluding any inline asm. | |||
9456 | bool HasUnknownCalleeNonAsm = false; | |||
9457 | }; | |||
9458 | ||||
9459 | struct AAFunctionReachabilityFunction : public AAFunctionReachability { | |||
9460 | AAFunctionReachabilityFunction(const IRPosition &IRP, Attributor &A) | |||
9461 | : AAFunctionReachability(IRP, A) {} | |||
9462 | ||||
9463 | bool canReach(Attributor &A, Function *Fn) const override { | |||
9464 | // Assume that we can reach any function if we can reach a call with | |||
9465 | // unknown callee. | |||
9466 | if (CanReachUnknownCallee) | |||
9467 | return true; | |||
9468 | ||||
9469 | if (ReachableQueries.count(Fn)) | |||
9470 | return true; | |||
9471 | ||||
9472 | if (UnreachableQueries.count(Fn)) | |||
9473 | return false; | |||
9474 | ||||
9475 | const AACallEdges &AAEdges = | |||
9476 | A.getAAFor<AACallEdges>(*this, getIRPosition(), DepClassTy::REQUIRED); | |||
9477 | ||||
9478 | const SetVector<Function *> &Edges = AAEdges.getOptimisticEdges(); | |||
9479 | bool Result = checkIfReachable(A, Edges, Fn); | |||
9480 | ||||
9481 | // Attributor returns attributes as const, so this function has to be | |||
9482 | // const for users of this attribute to use it without having to do | |||
9483 | // a const_cast. | |||
9484 | // This is a hack for us to be able to cache queries. | |||
9485 | auto *NonConstThis = const_cast<AAFunctionReachabilityFunction *>(this); | |||
9486 | ||||
9487 | if (Result) | |||
9488 | NonConstThis->ReachableQueries.insert(Fn); | |||
9489 | else | |||
9490 | NonConstThis->UnreachableQueries.insert(Fn); | |||
9491 | ||||
9492 | return Result; | |||
9493 | } | |||
9494 | ||||
9495 | /// See AbstractAttribute::updateImpl(...). | |||
9496 | ChangeStatus updateImpl(Attributor &A) override { | |||
9497 | if (CanReachUnknownCallee) | |||
9498 | return ChangeStatus::UNCHANGED; | |||
9499 | ||||
9500 | const AACallEdges &AAEdges = | |||
9501 | A.getAAFor<AACallEdges>(*this, getIRPosition(), DepClassTy::REQUIRED); | |||
9502 | const SetVector<Function *> &Edges = AAEdges.getOptimisticEdges(); | |||
9503 | ChangeStatus Change = ChangeStatus::UNCHANGED; | |||
9504 | ||||
9505 | if (AAEdges.hasUnknownCallee()) { | |||
9506 | bool OldCanReachUnknown = CanReachUnknownCallee; | |||
9507 | CanReachUnknownCallee = true; | |||
9508 | return OldCanReachUnknown ? ChangeStatus::UNCHANGED | |||
9509 | : ChangeStatus::CHANGED; | |||
9510 | } | |||
9511 | ||||
9512 | // Check if any of the unreachable functions become reachable. | |||
9513 | for (auto Current = UnreachableQueries.begin(); | |||
9514 | Current != UnreachableQueries.end();) { | |||
9515 | if (!checkIfReachable(A, Edges, *Current)) { | |||
9516 | Current++; | |||
9517 | continue; | |||
9518 | } | |||
9519 | ReachableQueries.insert(*Current); | |||
9520 | UnreachableQueries.erase(*Current++); | |||
9521 | Change = ChangeStatus::CHANGED; | |||
9522 | } | |||
9523 | ||||
9524 | return Change; | |||
9525 | } | |||
9526 | ||||
9527 | const std::string getAsStr() const override { | |||
9528 | size_t QueryCount = ReachableQueries.size() + UnreachableQueries.size(); | |||
9529 | ||||
9530 | return "FunctionReachability [" + std::to_string(ReachableQueries.size()) + | |||
9531 | "," + std::to_string(QueryCount) + "]"; | |||
9532 | } | |||
9533 | ||||
9534 | void trackStatistics() const override {} | |||
9535 | ||||
9536 | private: | |||
9537 | bool canReachUnknownCallee() const override { return CanReachUnknownCallee; } | |||
9538 | ||||
9539 | bool checkIfReachable(Attributor &A, const SetVector<Function *> &Edges, | |||
9540 | Function *Fn) const { | |||
9541 | if (Edges.count(Fn)) | |||
9542 | return true; | |||
9543 | ||||
9544 | for (Function *Edge : Edges) { | |||
9545 | // We don't need a dependency if the result is reachable. | |||
9546 | const AAFunctionReachability &EdgeReachability = | |||
9547 | A.getAAFor<AAFunctionReachability>(*this, IRPosition::function(*Edge), | |||
9548 | DepClassTy::NONE); | |||
9549 | ||||
9550 | if (EdgeReachability.canReach(A, Fn)) | |||
9551 | return true; | |||
9552 | } | |||
9553 | for (Function *Fn : Edges) | |||
9554 | A.getAAFor<AAFunctionReachability>(*this, IRPosition::function(*Fn), | |||
9555 | DepClassTy::REQUIRED); | |||
9556 | ||||
9557 | return false; | |||
9558 | } | |||
9559 | ||||
9560 | /// Set of functions that we know for sure is reachable. | |||
9561 | SmallPtrSet<Function *, 8> ReachableQueries; | |||
9562 | ||||
9563 | /// Set of functions that are unreachable, but might become reachable. | |||
9564 | SmallPtrSet<Function *, 8> UnreachableQueries; | |||
9565 | ||||
9566 | /// If we can reach a function with a call to a unknown function we assume | |||
9567 | /// that we can reach any function. | |||
9568 | bool CanReachUnknownCallee = false; | |||
9569 | }; | |||
9570 | ||||
9571 | } // namespace | |||
9572 | ||||
9573 | AACallGraphNode *AACallEdgeIterator::operator*() const { | |||
9574 | return static_cast<AACallGraphNode *>(const_cast<AACallEdges *>( | |||
9575 | &A.getOrCreateAAFor<AACallEdges>(IRPosition::function(**I)))); | |||
9576 | } | |||
9577 | ||||
9578 | void AttributorCallGraph::print() { llvm::WriteGraph(outs(), this); } | |||
9579 | ||||
9580 | const char AAReturnedValues::ID = 0; | |||
9581 | const char AANoUnwind::ID = 0; | |||
9582 | const char AANoSync::ID = 0; | |||
9583 | const char AANoFree::ID = 0; | |||
9584 | const char AANonNull::ID = 0; | |||
9585 | const char AANoRecurse::ID = 0; | |||
9586 | const char AAWillReturn::ID = 0; | |||
9587 | const char AAUndefinedBehavior::ID = 0; | |||
9588 | const char AANoAlias::ID = 0; | |||
9589 | const char AAReachability::ID = 0; | |||
9590 | const char AANoReturn::ID = 0; | |||
9591 | const char AAIsDead::ID = 0; | |||
9592 | const char AADereferenceable::ID = 0; | |||
9593 | const char AAAlign::ID = 0; | |||
9594 | const char AANoCapture::ID = 0; | |||
9595 | const char AAValueSimplify::ID = 0; | |||
9596 | const char AAHeapToStack::ID = 0; | |||
9597 | const char AAPrivatizablePtr::ID = 0; | |||
9598 | const char AAMemoryBehavior::ID = 0; | |||
9599 | const char AAMemoryLocation::ID = 0; | |||
9600 | const char AAValueConstantRange::ID = 0; | |||
9601 | const char AAPotentialValues::ID = 0; | |||
9602 | const char AANoUndef::ID = 0; | |||
9603 | const char AACallEdges::ID = 0; | |||
9604 | const char AAFunctionReachability::ID = 0; | |||
9605 | const char AAPointerInfo::ID = 0; | |||
9606 | ||||
9607 | // Macro magic to create the static generator function for attributes that | |||
9608 | // follow the naming scheme. | |||
9609 | ||||
9610 | #define SWITCH_PK_INV(CLASS, PK, POS_NAME) \ | |||
9611 | case IRPosition::PK: \ | |||
9612 | llvm_unreachable("Cannot create " #CLASS " for a " POS_NAME " position!")__builtin_unreachable(); | |||
9613 | ||||
9614 | #define SWITCH_PK_CREATE(CLASS, IRP, PK, SUFFIX) \ | |||
9615 | case IRPosition::PK: \ | |||
9616 | AA = new (A.Allocator) CLASS##SUFFIX(IRP, A); \ | |||
9617 | ++NumAAs; \ | |||
9618 | break; | |||
9619 | ||||
9620 | #define CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ | |||
9621 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ | |||
9622 | CLASS *AA = nullptr; \ | |||
9623 | switch (IRP.getPositionKind()) { \ | |||
9624 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ | |||
9625 | SWITCH_PK_INV(CLASS, IRP_FLOAT, "floating") \ | |||
9626 | SWITCH_PK_INV(CLASS, IRP_ARGUMENT, "argument") \ | |||
9627 | SWITCH_PK_INV(CLASS, IRP_RETURNED, "returned") \ | |||
9628 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_RETURNED, "call site returned") \ | |||
9629 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_ARGUMENT, "call site argument") \ | |||
9630 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ | |||
9631 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE, CallSite) \ | |||
9632 | } \ | |||
9633 | return *AA; \ | |||
9634 | } | |||
9635 | ||||
9636 | #define CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ | |||
9637 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ | |||
9638 | CLASS *AA = nullptr; \ | |||
9639 | switch (IRP.getPositionKind()) { \ | |||
9640 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ | |||
9641 | SWITCH_PK_INV(CLASS, IRP_FUNCTION, "function") \ | |||
9642 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE, "call site") \ | |||
9643 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FLOAT, Floating) \ | |||
9644 | SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument) \ | |||
9645 | SWITCH_PK_CREATE(CLASS, IRP, IRP_RETURNED, Returned) \ | |||
9646 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned) \ | |||
9647 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument) \ | |||
9648 | } \ | |||
9649 | return *AA; \ | |||
9650 | } | |||
9651 | ||||
9652 | #define CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ | |||
9653 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ | |||
9654 | CLASS *AA = nullptr; \ | |||
9655 | switch (IRP.getPositionKind()) { \ | |||
9656 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ | |||
9657 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ | |||
9658 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE, CallSite) \ | |||
9659 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FLOAT, Floating) \ | |||
9660 | SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument) \ | |||
9661 | SWITCH_PK_CREATE(CLASS, IRP, IRP_RETURNED, Returned) \ | |||
9662 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned) \ | |||
9663 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument) \ | |||
9664 | } \ | |||
9665 | return *AA; \ | |||
9666 | } | |||
9667 | ||||
9668 | #define CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ | |||
9669 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ | |||
9670 | CLASS *AA = nullptr; \ | |||
9671 | switch (IRP.getPositionKind()) { \ | |||
9672 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ | |||
9673 | SWITCH_PK_INV(CLASS, IRP_ARGUMENT, "argument") \ | |||
9674 | SWITCH_PK_INV(CLASS, IRP_FLOAT, "floating") \ | |||
9675 | SWITCH_PK_INV(CLASS, IRP_RETURNED, "returned") \ | |||
9676 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_RETURNED, "call site returned") \ | |||
9677 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_ARGUMENT, "call site argument") \ | |||
9678 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE, "call site") \ | |||
9679 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ | |||
9680 | } \ | |||
9681 | return *AA; \ | |||
9682 | } | |||
9683 | ||||
9684 | #define CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ | |||
9685 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ | |||
9686 | CLASS *AA = nullptr; \ | |||
9687 | switch (IRP.getPositionKind()) { \ | |||
9688 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ | |||
9689 | SWITCH_PK_INV(CLASS, IRP_RETURNED, "returned") \ | |||
9690 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ | |||
9691 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE, CallSite) \ | |||
9692 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FLOAT, Floating) \ | |||
9693 | SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument) \ | |||
9694 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned) \ | |||
9695 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument) \ | |||
9696 | } \ | |||
9697 | return *AA; \ | |||
9698 | } | |||
9699 | ||||
9700 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoUnwind) | |||
9701 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoSync) | |||
9702 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoRecurse) | |||
9703 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAWillReturn) | |||
9704 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoReturn) | |||
9705 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAReturnedValues) | |||
9706 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAMemoryLocation) | |||
9707 | ||||
9708 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANonNull) | |||
9709 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoAlias) | |||
9710 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAPrivatizablePtr) | |||
9711 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AADereferenceable) | |||
9712 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAAlign) | |||
9713 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoCapture) | |||
9714 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAValueConstantRange) | |||
9715 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAPotentialValues) | |||
9716 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoUndef) | |||
9717 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAPointerInfo) | |||
9718 | ||||
9719 | CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAValueSimplify) | |||
9720 | CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAIsDead) | |||
9721 | CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoFree) | |||
9722 | ||||
9723 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAHeapToStack) | |||
9724 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAReachability) | |||
9725 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAUndefinedBehavior) | |||
| ||||
9726 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AACallEdges) | |||
9727 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAFunctionReachability) | |||
9728 | ||||
9729 | CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAMemoryBehavior) | |||
9730 | ||||
9731 | #undef CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION | |||
9732 | #undef CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION | |||
9733 | #undef CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION | |||
9734 | #undef CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION | |||
9735 | #undef CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION | |||
9736 | #undef SWITCH_PK_CREATE | |||
9737 | #undef SWITCH_PK_INV |
1 | //===- Allocator.h - Simple memory allocation abstraction -------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | /// \file |
9 | /// |
10 | /// This file defines the BumpPtrAllocator interface. BumpPtrAllocator conforms |
11 | /// to the LLVM "Allocator" concept and is similar to MallocAllocator, but |
12 | /// objects cannot be deallocated. Their lifetime is tied to the lifetime of the |
13 | /// allocator. |
14 | /// |
15 | //===----------------------------------------------------------------------===// |
16 | |
17 | #ifndef LLVM_SUPPORT_ALLOCATOR_H |
18 | #define LLVM_SUPPORT_ALLOCATOR_H |
19 | |
20 | #include "llvm/ADT/Optional.h" |
21 | #include "llvm/ADT/SmallVector.h" |
22 | #include "llvm/Support/Alignment.h" |
23 | #include "llvm/Support/AllocatorBase.h" |
24 | #include "llvm/Support/Compiler.h" |
25 | #include "llvm/Support/ErrorHandling.h" |
26 | #include "llvm/Support/MathExtras.h" |
27 | #include "llvm/Support/MemAlloc.h" |
28 | #include <algorithm> |
29 | #include <cassert> |
30 | #include <cstddef> |
31 | #include <cstdint> |
32 | #include <cstdlib> |
33 | #include <iterator> |
34 | #include <type_traits> |
35 | #include <utility> |
36 | |
37 | namespace llvm { |
38 | |
39 | namespace detail { |
40 | |
41 | // We call out to an external function to actually print the message as the |
42 | // printing code uses Allocator.h in its implementation. |
43 | void printBumpPtrAllocatorStats(unsigned NumSlabs, size_t BytesAllocated, |
44 | size_t TotalMemory); |
45 | |
46 | } // end namespace detail |
47 | |
48 | /// Allocate memory in an ever growing pool, as if by bump-pointer. |
49 | /// |
50 | /// This isn't strictly a bump-pointer allocator as it uses backing slabs of |
51 | /// memory rather than relying on a boundless contiguous heap. However, it has |
52 | /// bump-pointer semantics in that it is a monotonically growing pool of memory |
53 | /// where every allocation is found by merely allocating the next N bytes in |
54 | /// the slab, or the next N bytes in the next slab. |
55 | /// |
56 | /// Note that this also has a threshold for forcing allocations above a certain |
57 | /// size into their own slab. |
58 | /// |
59 | /// The BumpPtrAllocatorImpl template defaults to using a MallocAllocator |
60 | /// object, which wraps malloc, to allocate memory, but it can be changed to |
61 | /// use a custom allocator. |
62 | /// |
63 | /// The GrowthDelay specifies after how many allocated slabs the allocator |
64 | /// increases the size of the slabs. |
65 | template <typename AllocatorT = MallocAllocator, size_t SlabSize = 4096, |
66 | size_t SizeThreshold = SlabSize, size_t GrowthDelay = 128> |
67 | class BumpPtrAllocatorImpl |
68 | : public AllocatorBase<BumpPtrAllocatorImpl<AllocatorT, SlabSize, |
69 | SizeThreshold, GrowthDelay>>, |
70 | private AllocatorT { |
71 | public: |
72 | static_assert(SizeThreshold <= SlabSize, |
73 | "The SizeThreshold must be at most the SlabSize to ensure " |
74 | "that objects larger than a slab go into their own memory " |
75 | "allocation."); |
76 | static_assert(GrowthDelay > 0, |
77 | "GrowthDelay must be at least 1 which already increases the" |
78 | "slab size after each allocated slab."); |
79 | |
80 | BumpPtrAllocatorImpl() = default; |
81 | |
82 | template <typename T> |
83 | BumpPtrAllocatorImpl(T &&Allocator) |
84 | : AllocatorT(std::forward<T &&>(Allocator)) {} |
85 | |
86 | // Manually implement a move constructor as we must clear the old allocator's |
87 | // slabs as a matter of correctness. |
88 | BumpPtrAllocatorImpl(BumpPtrAllocatorImpl &&Old) |
89 | : AllocatorT(static_cast<AllocatorT &&>(Old)), CurPtr(Old.CurPtr), |
90 | End(Old.End), Slabs(std::move(Old.Slabs)), |
91 | CustomSizedSlabs(std::move(Old.CustomSizedSlabs)), |
92 | BytesAllocated(Old.BytesAllocated), RedZoneSize(Old.RedZoneSize) { |
93 | Old.CurPtr = Old.End = nullptr; |
94 | Old.BytesAllocated = 0; |
95 | Old.Slabs.clear(); |
96 | Old.CustomSizedSlabs.clear(); |
97 | } |
98 | |
99 | ~BumpPtrAllocatorImpl() { |
100 | DeallocateSlabs(Slabs.begin(), Slabs.end()); |
101 | DeallocateCustomSizedSlabs(); |
102 | } |
103 | |
104 | BumpPtrAllocatorImpl &operator=(BumpPtrAllocatorImpl &&RHS) { |
105 | DeallocateSlabs(Slabs.begin(), Slabs.end()); |
106 | DeallocateCustomSizedSlabs(); |
107 | |
108 | CurPtr = RHS.CurPtr; |
109 | End = RHS.End; |
110 | BytesAllocated = RHS.BytesAllocated; |
111 | RedZoneSize = RHS.RedZoneSize; |
112 | Slabs = std::move(RHS.Slabs); |
113 | CustomSizedSlabs = std::move(RHS.CustomSizedSlabs); |
114 | AllocatorT::operator=(static_cast<AllocatorT &&>(RHS)); |
115 | |
116 | RHS.CurPtr = RHS.End = nullptr; |
117 | RHS.BytesAllocated = 0; |
118 | RHS.Slabs.clear(); |
119 | RHS.CustomSizedSlabs.clear(); |
120 | return *this; |
121 | } |
122 | |
123 | /// Deallocate all but the current slab and reset the current pointer |
124 | /// to the beginning of it, freeing all memory allocated so far. |
125 | void Reset() { |
126 | // Deallocate all but the first slab, and deallocate all custom-sized slabs. |
127 | DeallocateCustomSizedSlabs(); |
128 | CustomSizedSlabs.clear(); |
129 | |
130 | if (Slabs.empty()) |
131 | return; |
132 | |
133 | // Reset the state. |
134 | BytesAllocated = 0; |
135 | CurPtr = (char *)Slabs.front(); |
136 | End = CurPtr + SlabSize; |
137 | |
138 | __asan_poison_memory_region(*Slabs.begin(), computeSlabSize(0)); |
139 | DeallocateSlabs(std::next(Slabs.begin()), Slabs.end()); |
140 | Slabs.erase(std::next(Slabs.begin()), Slabs.end()); |
141 | } |
142 | |
143 | /// Allocate space at the specified alignment. |
144 | LLVM_ATTRIBUTE_RETURNS_NONNULL__attribute__((returns_nonnull)) LLVM_ATTRIBUTE_RETURNS_NOALIAS__attribute__((__malloc__)) void * |
145 | Allocate(size_t Size, Align Alignment) { |
146 | // Keep track of how many bytes we've allocated. |
147 | BytesAllocated += Size; |
148 | |
149 | size_t Adjustment = offsetToAlignedAddr(CurPtr, Alignment); |
150 | assert(Adjustment + Size >= Size && "Adjustment + Size must not overflow")((void)0); |
151 | |
152 | size_t SizeToAllocate = Size; |
153 | #if LLVM_ADDRESS_SANITIZER_BUILD0 |
154 | // Add trailing bytes as a "red zone" under ASan. |
155 | SizeToAllocate += RedZoneSize; |
156 | #endif |
157 | |
158 | // Check if we have enough space. |
159 | if (Adjustment + SizeToAllocate <= size_t(End - CurPtr)) { |
160 | char *AlignedPtr = CurPtr + Adjustment; |
161 | CurPtr = AlignedPtr + SizeToAllocate; |
162 | // Update the allocation point of this memory block in MemorySanitizer. |
163 | // Without this, MemorySanitizer messages for values originated from here |
164 | // will point to the allocation of the entire slab. |
165 | __msan_allocated_memory(AlignedPtr, Size); |
166 | // Similarly, tell ASan about this space. |
167 | __asan_unpoison_memory_region(AlignedPtr, Size); |
168 | return AlignedPtr; |
169 | } |
170 | |
171 | // If Size is really big, allocate a separate slab for it. |
172 | size_t PaddedSize = SizeToAllocate + Alignment.value() - 1; |
173 | if (PaddedSize > SizeThreshold) { |
174 | void *NewSlab = |
175 | AllocatorT::Allocate(PaddedSize, alignof(std::max_align_t)); |
176 | // We own the new slab and don't want anyone reading anyting other than |
177 | // pieces returned from this method. So poison the whole slab. |
178 | __asan_poison_memory_region(NewSlab, PaddedSize); |
179 | CustomSizedSlabs.push_back(std::make_pair(NewSlab, PaddedSize)); |
180 | |
181 | uintptr_t AlignedAddr = alignAddr(NewSlab, Alignment); |
182 | assert(AlignedAddr + Size <= (uintptr_t)NewSlab + PaddedSize)((void)0); |
183 | char *AlignedPtr = (char*)AlignedAddr; |
184 | __msan_allocated_memory(AlignedPtr, Size); |
185 | __asan_unpoison_memory_region(AlignedPtr, Size); |
186 | return AlignedPtr; |
187 | } |
188 | |
189 | // Otherwise, start a new slab and try again. |
190 | StartNewSlab(); |
191 | uintptr_t AlignedAddr = alignAddr(CurPtr, Alignment); |
192 | assert(AlignedAddr + SizeToAllocate <= (uintptr_t)End &&((void)0) |
193 | "Unable to allocate memory!")((void)0); |
194 | char *AlignedPtr = (char*)AlignedAddr; |
195 | CurPtr = AlignedPtr + SizeToAllocate; |
196 | __msan_allocated_memory(AlignedPtr, Size); |
197 | __asan_unpoison_memory_region(AlignedPtr, Size); |
198 | return AlignedPtr; |
199 | } |
200 | |
201 | inline LLVM_ATTRIBUTE_RETURNS_NONNULL__attribute__((returns_nonnull)) LLVM_ATTRIBUTE_RETURNS_NOALIAS__attribute__((__malloc__)) void * |
202 | Allocate(size_t Size, size_t Alignment) { |
203 | assert(Alignment > 0 && "0-byte alignment is not allowed. Use 1 instead.")((void)0); |
204 | return Allocate(Size, Align(Alignment)); |
205 | } |
206 | |
207 | // Pull in base class overloads. |
208 | using AllocatorBase<BumpPtrAllocatorImpl>::Allocate; |
209 | |
210 | // Bump pointer allocators are expected to never free their storage; and |
211 | // clients expect pointers to remain valid for non-dereferencing uses even |
212 | // after deallocation. |
213 | void Deallocate(const void *Ptr, size_t Size, size_t /*Alignment*/) { |
214 | __asan_poison_memory_region(Ptr, Size); |
215 | } |
216 | |
217 | // Pull in base class overloads. |
218 | using AllocatorBase<BumpPtrAllocatorImpl>::Deallocate; |
219 | |
220 | size_t GetNumSlabs() const { return Slabs.size() + CustomSizedSlabs.size(); } |
221 | |
222 | /// \return An index uniquely and reproducibly identifying |
223 | /// an input pointer \p Ptr in the given allocator. |
224 | /// The returned value is negative iff the object is inside a custom-size |
225 | /// slab. |
226 | /// Returns an empty optional if the pointer is not found in the allocator. |
227 | llvm::Optional<int64_t> identifyObject(const void *Ptr) { |
228 | const char *P = static_cast<const char *>(Ptr); |
229 | int64_t InSlabIdx = 0; |
230 | for (size_t Idx = 0, E = Slabs.size(); Idx < E; Idx++) { |
231 | const char *S = static_cast<const char *>(Slabs[Idx]); |
232 | if (P >= S && P < S + computeSlabSize(Idx)) |
233 | return InSlabIdx + static_cast<int64_t>(P - S); |
234 | InSlabIdx += static_cast<int64_t>(computeSlabSize(Idx)); |
235 | } |
236 | |
237 | // Use negative index to denote custom sized slabs. |
238 | int64_t InCustomSizedSlabIdx = -1; |
239 | for (size_t Idx = 0, E = CustomSizedSlabs.size(); Idx < E; Idx++) { |
240 | const char *S = static_cast<const char *>(CustomSizedSlabs[Idx].first); |
241 | size_t Size = CustomSizedSlabs[Idx].second; |
242 | if (P >= S && P < S + Size) |
243 | return InCustomSizedSlabIdx - static_cast<int64_t>(P - S); |
244 | InCustomSizedSlabIdx -= static_cast<int64_t>(Size); |
245 | } |
246 | return None; |
247 | } |
248 | |
249 | /// A wrapper around identifyObject that additionally asserts that |
250 | /// the object is indeed within the allocator. |
251 | /// \return An index uniquely and reproducibly identifying |
252 | /// an input pointer \p Ptr in the given allocator. |
253 | int64_t identifyKnownObject(const void *Ptr) { |
254 | Optional<int64_t> Out = identifyObject(Ptr); |
255 | assert(Out && "Wrong allocator used")((void)0); |
256 | return *Out; |
257 | } |
258 | |
259 | /// A wrapper around identifyKnownObject. Accepts type information |
260 | /// about the object and produces a smaller identifier by relying on |
261 | /// the alignment information. Note that sub-classes may have different |
262 | /// alignment, so the most base class should be passed as template parameter |
263 | /// in order to obtain correct results. For that reason automatic template |
264 | /// parameter deduction is disabled. |
265 | /// \return An index uniquely and reproducibly identifying |
266 | /// an input pointer \p Ptr in the given allocator. This identifier is |
267 | /// different from the ones produced by identifyObject and |
268 | /// identifyAlignedObject. |
269 | template <typename T> |
270 | int64_t identifyKnownAlignedObject(const void *Ptr) { |
271 | int64_t Out = identifyKnownObject(Ptr); |
272 | assert(Out % alignof(T) == 0 && "Wrong alignment information")((void)0); |
273 | return Out / alignof(T); |
274 | } |
275 | |
276 | size_t getTotalMemory() const { |
277 | size_t TotalMemory = 0; |
278 | for (auto I = Slabs.begin(), E = Slabs.end(); I != E; ++I) |
279 | TotalMemory += computeSlabSize(std::distance(Slabs.begin(), I)); |
280 | for (auto &PtrAndSize : CustomSizedSlabs) |
281 | TotalMemory += PtrAndSize.second; |
282 | return TotalMemory; |
283 | } |
284 | |
285 | size_t getBytesAllocated() const { return BytesAllocated; } |
286 | |
287 | void setRedZoneSize(size_t NewSize) { |
288 | RedZoneSize = NewSize; |
289 | } |
290 | |
291 | void PrintStats() const { |
292 | detail::printBumpPtrAllocatorStats(Slabs.size(), BytesAllocated, |
293 | getTotalMemory()); |
294 | } |
295 | |
296 | private: |
297 | /// The current pointer into the current slab. |
298 | /// |
299 | /// This points to the next free byte in the slab. |
300 | char *CurPtr = nullptr; |
301 | |
302 | /// The end of the current slab. |
303 | char *End = nullptr; |
304 | |
305 | /// The slabs allocated so far. |
306 | SmallVector<void *, 4> Slabs; |
307 | |
308 | /// Custom-sized slabs allocated for too-large allocation requests. |
309 | SmallVector<std::pair<void *, size_t>, 0> CustomSizedSlabs; |
310 | |
311 | /// How many bytes we've allocated. |
312 | /// |
313 | /// Used so that we can compute how much space was wasted. |
314 | size_t BytesAllocated = 0; |
315 | |
316 | /// The number of bytes to put between allocations when running under |
317 | /// a sanitizer. |
318 | size_t RedZoneSize = 1; |
319 | |
320 | static size_t computeSlabSize(unsigned SlabIdx) { |
321 | // Scale the actual allocated slab size based on the number of slabs |
322 | // allocated. Every GrowthDelay slabs allocated, we double |
323 | // the allocated size to reduce allocation frequency, but saturate at |
324 | // multiplying the slab size by 2^30. |
325 | return SlabSize * |
326 | ((size_t)1 << std::min<size_t>(30, SlabIdx / GrowthDelay)); |
327 | } |
328 | |
329 | /// Allocate a new slab and move the bump pointers over into the new |
330 | /// slab, modifying CurPtr and End. |
331 | void StartNewSlab() { |
332 | size_t AllocatedSlabSize = computeSlabSize(Slabs.size()); |
333 | |
334 | void *NewSlab = |
335 | AllocatorT::Allocate(AllocatedSlabSize, alignof(std::max_align_t)); |
336 | // We own the new slab and don't want anyone reading anything other than |
337 | // pieces returned from this method. So poison the whole slab. |
338 | __asan_poison_memory_region(NewSlab, AllocatedSlabSize); |
339 | |
340 | Slabs.push_back(NewSlab); |
341 | CurPtr = (char *)(NewSlab); |
342 | End = ((char *)NewSlab) + AllocatedSlabSize; |
343 | } |
344 | |
345 | /// Deallocate a sequence of slabs. |
346 | void DeallocateSlabs(SmallVectorImpl<void *>::iterator I, |
347 | SmallVectorImpl<void *>::iterator E) { |
348 | for (; I != E; ++I) { |
349 | size_t AllocatedSlabSize = |
350 | computeSlabSize(std::distance(Slabs.begin(), I)); |
351 | AllocatorT::Deallocate(*I, AllocatedSlabSize, alignof(std::max_align_t)); |
352 | } |
353 | } |
354 | |
355 | /// Deallocate all memory for custom sized slabs. |
356 | void DeallocateCustomSizedSlabs() { |
357 | for (auto &PtrAndSize : CustomSizedSlabs) { |
358 | void *Ptr = PtrAndSize.first; |
359 | size_t Size = PtrAndSize.second; |
360 | AllocatorT::Deallocate(Ptr, Size, alignof(std::max_align_t)); |
361 | } |
362 | } |
363 | |
364 | template <typename T> friend class SpecificBumpPtrAllocator; |
365 | }; |
366 | |
367 | /// The standard BumpPtrAllocator which just uses the default template |
368 | /// parameters. |
369 | typedef BumpPtrAllocatorImpl<> BumpPtrAllocator; |
370 | |
371 | /// A BumpPtrAllocator that allows only elements of a specific type to be |
372 | /// allocated. |
373 | /// |
374 | /// This allows calling the destructor in DestroyAll() and when the allocator is |
375 | /// destroyed. |
376 | template <typename T> class SpecificBumpPtrAllocator { |
377 | BumpPtrAllocator Allocator; |
378 | |
379 | public: |
380 | SpecificBumpPtrAllocator() { |
381 | // Because SpecificBumpPtrAllocator walks the memory to call destructors, |
382 | // it can't have red zones between allocations. |
383 | Allocator.setRedZoneSize(0); |
384 | } |
385 | SpecificBumpPtrAllocator(SpecificBumpPtrAllocator &&Old) |
386 | : Allocator(std::move(Old.Allocator)) {} |
387 | ~SpecificBumpPtrAllocator() { DestroyAll(); } |
388 | |
389 | SpecificBumpPtrAllocator &operator=(SpecificBumpPtrAllocator &&RHS) { |
390 | Allocator = std::move(RHS.Allocator); |
391 | return *this; |
392 | } |
393 | |
394 | /// Call the destructor of each allocated object and deallocate all but the |
395 | /// current slab and reset the current pointer to the beginning of it, freeing |
396 | /// all memory allocated so far. |
397 | void DestroyAll() { |
398 | auto DestroyElements = [](char *Begin, char *End) { |
399 | assert(Begin == (char *)alignAddr(Begin, Align::Of<T>()))((void)0); |
400 | for (char *Ptr = Begin; Ptr + sizeof(T) <= End; Ptr += sizeof(T)) |
401 | reinterpret_cast<T *>(Ptr)->~T(); |
402 | }; |
403 | |
404 | for (auto I = Allocator.Slabs.begin(), E = Allocator.Slabs.end(); I != E; |
405 | ++I) { |
406 | size_t AllocatedSlabSize = BumpPtrAllocator::computeSlabSize( |
407 | std::distance(Allocator.Slabs.begin(), I)); |
408 | char *Begin = (char *)alignAddr(*I, Align::Of<T>()); |
409 | char *End = *I == Allocator.Slabs.back() ? Allocator.CurPtr |
410 | : (char *)*I + AllocatedSlabSize; |
411 | |
412 | DestroyElements(Begin, End); |
413 | } |
414 | |
415 | for (auto &PtrAndSize : Allocator.CustomSizedSlabs) { |
416 | void *Ptr = PtrAndSize.first; |
417 | size_t Size = PtrAndSize.second; |
418 | DestroyElements((char *)alignAddr(Ptr, Align::Of<T>()), |
419 | (char *)Ptr + Size); |
420 | } |
421 | |
422 | Allocator.Reset(); |
423 | } |
424 | |
425 | /// Allocate space for an array of objects without constructing them. |
426 | T *Allocate(size_t num = 1) { return Allocator.Allocate<T>(num); } |
427 | }; |
428 | |
429 | } // end namespace llvm |
430 | |
431 | template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold, |
432 | size_t GrowthDelay> |
433 | void * |
434 | operator new(size_t Size, |
435 | llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize, SizeThreshold, |
436 | GrowthDelay> &Allocator) { |
437 | return Allocator.Allocate(Size, std::min((size_t)llvm::NextPowerOf2(Size), |
438 | alignof(std::max_align_t))); |
439 | } |
440 | |
441 | template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold, |
442 | size_t GrowthDelay> |
443 | void operator delete(void *, |
444 | llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize, |
445 | SizeThreshold, GrowthDelay> &) { |
446 | } |
447 | |
448 | #endif // LLVM_SUPPORT_ALLOCATOR_H |
1 | //===-- llvm/Support/Alignment.h - Useful alignment functions ---*- C++ -*-===// | |||
2 | // | |||
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |||
4 | // See https://llvm.org/LICENSE.txt for license information. | |||
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |||
6 | // | |||
7 | //===----------------------------------------------------------------------===// | |||
8 | // | |||
9 | // This file contains types to represent alignments. | |||
10 | // They are instrumented to guarantee some invariants are preserved and prevent | |||
11 | // invalid manipulations. | |||
12 | // | |||
13 | // - Align represents an alignment in bytes, it is always set and always a valid | |||
14 | // power of two, its minimum value is 1 which means no alignment requirements. | |||
15 | // | |||
16 | // - MaybeAlign is an optional type, it may be undefined or set. When it's set | |||
17 | // you can get the underlying Align type by using the getValue() method. | |||
18 | // | |||
19 | //===----------------------------------------------------------------------===// | |||
20 | ||||
21 | #ifndef LLVM_SUPPORT_ALIGNMENT_H_ | |||
22 | #define LLVM_SUPPORT_ALIGNMENT_H_ | |||
23 | ||||
24 | #include "llvm/ADT/Optional.h" | |||
25 | #include "llvm/Support/MathExtras.h" | |||
26 | #include <cassert> | |||
27 | #ifndef NDEBUG1 | |||
28 | #include <string> | |||
29 | #endif // NDEBUG | |||
30 | ||||
31 | namespace llvm { | |||
32 | ||||
33 | #define ALIGN_CHECK_ISPOSITIVE(decl) \ | |||
34 | assert(decl > 0 && (#decl " should be defined"))((void)0) | |||
35 | ||||
36 | /// This struct is a compact representation of a valid (non-zero power of two) | |||
37 | /// alignment. | |||
38 | /// It is suitable for use as static global constants. | |||
39 | struct Align { | |||
40 | private: | |||
41 | uint8_t ShiftValue = 0; /// The log2 of the required alignment. | |||
42 | /// ShiftValue is less than 64 by construction. | |||
43 | ||||
44 | friend struct MaybeAlign; | |||
45 | friend unsigned Log2(Align); | |||
46 | friend bool operator==(Align Lhs, Align Rhs); | |||
47 | friend bool operator!=(Align Lhs, Align Rhs); | |||
48 | friend bool operator<=(Align Lhs, Align Rhs); | |||
49 | friend bool operator>=(Align Lhs, Align Rhs); | |||
50 | friend bool operator<(Align Lhs, Align Rhs); | |||
51 | friend bool operator>(Align Lhs, Align Rhs); | |||
52 | friend unsigned encode(struct MaybeAlign A); | |||
53 | friend struct MaybeAlign decodeMaybeAlign(unsigned Value); | |||
54 | ||||
55 | /// A trivial type to allow construction of constexpr Align. | |||
56 | /// This is currently needed to workaround a bug in GCC 5.3 which prevents | |||
57 | /// definition of constexpr assign operators. | |||
58 | /// https://stackoverflow.com/questions/46756288/explicitly-defaulted-function-cannot-be-declared-as-constexpr-because-the-implic | |||
59 | /// FIXME: Remove this, make all assign operators constexpr and introduce user | |||
60 | /// defined literals when we don't have to support GCC 5.3 anymore. | |||
61 | /// https://llvm.org/docs/GettingStarted.html#getting-a-modern-host-c-toolchain | |||
62 | struct LogValue { | |||
63 | uint8_t Log; | |||
64 | }; | |||
65 | ||||
66 | public: | |||
67 | /// Default is byte-aligned. | |||
68 | constexpr Align() = default; | |||
69 | /// Do not perform checks in case of copy/move construct/assign, because the | |||
70 | /// checks have been performed when building `Other`. | |||
71 | constexpr Align(const Align &Other) = default; | |||
72 | constexpr Align(Align &&Other) = default; | |||
73 | Align &operator=(const Align &Other) = default; | |||
74 | Align &operator=(Align &&Other) = default; | |||
75 | ||||
76 | explicit Align(uint64_t Value) { | |||
77 | assert(Value > 0 && "Value must not be 0")((void)0); | |||
78 | assert(llvm::isPowerOf2_64(Value) && "Alignment is not a power of 2")((void)0); | |||
79 | ShiftValue = Log2_64(Value); | |||
80 | assert(ShiftValue < 64 && "Broken invariant")((void)0); | |||
81 | } | |||
82 | ||||
83 | /// This is a hole in the type system and should not be abused. | |||
84 | /// Needed to interact with C for instance. | |||
85 | uint64_t value() const { return uint64_t(1) << ShiftValue; } | |||
| ||||
86 | ||||
87 | /// Allow constructions of constexpr Align. | |||
88 | template <size_t kValue> constexpr static LogValue Constant() { | |||
89 | return LogValue{static_cast<uint8_t>(CTLog2<kValue>())}; | |||
90 | } | |||
91 | ||||
92 | /// Allow constructions of constexpr Align from types. | |||
93 | /// Compile time equivalent to Align(alignof(T)). | |||
94 | template <typename T> constexpr static LogValue Of() { | |||
95 | return Constant<std::alignment_of<T>::value>(); | |||
96 | } | |||
97 | ||||
98 | /// Constexpr constructor from LogValue type. | |||
99 | constexpr Align(LogValue CA) : ShiftValue(CA.Log) {} | |||
100 | }; | |||
101 | ||||
102 | /// Treats the value 0 as a 1, so Align is always at least 1. | |||
103 | inline Align assumeAligned(uint64_t Value) { | |||
104 | return Value ? Align(Value) : Align(); | |||
105 | } | |||
106 | ||||
107 | /// This struct is a compact representation of a valid (power of two) or | |||
108 | /// undefined (0) alignment. | |||
109 | struct MaybeAlign : public llvm::Optional<Align> { | |||
110 | private: | |||
111 | using UP = llvm::Optional<Align>; | |||
112 | ||||
113 | public: | |||
114 | /// Default is undefined. | |||
115 | MaybeAlign() = default; | |||
116 | /// Do not perform checks in case of copy/move construct/assign, because the | |||
117 | /// checks have been performed when building `Other`. | |||
118 | MaybeAlign(const MaybeAlign &Other) = default; | |||
119 | MaybeAlign &operator=(const MaybeAlign &Other) = default; | |||
120 | MaybeAlign(MaybeAlign &&Other) = default; | |||
121 | MaybeAlign &operator=(MaybeAlign &&Other) = default; | |||
122 | ||||
123 | /// Use llvm::Optional<Align> constructor. | |||
124 | using UP::UP; | |||
125 | ||||
126 | explicit MaybeAlign(uint64_t Value) { | |||
127 | assert((Value == 0 || llvm::isPowerOf2_64(Value)) &&((void)0) | |||
128 | "Alignment is neither 0 nor a power of 2")((void)0); | |||
129 | if (Value) | |||
130 | emplace(Value); | |||
131 | } | |||
132 | ||||
133 | /// For convenience, returns a valid alignment or 1 if undefined. | |||
134 | Align valueOrOne() const { return hasValue() ? getValue() : Align(); } | |||
135 | }; | |||
136 | ||||
137 | /// Checks that SizeInBytes is a multiple of the alignment. | |||
138 | inline bool isAligned(Align Lhs, uint64_t SizeInBytes) { | |||
139 | return SizeInBytes % Lhs.value() == 0; | |||
140 | } | |||
141 | ||||
142 | /// Checks that Addr is a multiple of the alignment. | |||
143 | inline bool isAddrAligned(Align Lhs, const void *Addr) { | |||
144 | return isAligned(Lhs, reinterpret_cast<uintptr_t>(Addr)); | |||
145 | } | |||
146 | ||||
147 | /// Returns a multiple of A needed to store `Size` bytes. | |||
148 | inline uint64_t alignTo(uint64_t Size, Align A) { | |||
149 | const uint64_t Value = A.value(); | |||
150 | // The following line is equivalent to `(Size + Value - 1) / Value * Value`. | |||
151 | ||||
152 | // The division followed by a multiplication can be thought of as a right | |||
153 | // shift followed by a left shift which zeros out the extra bits produced in | |||
154 | // the bump; `~(Value - 1)` is a mask where all those bits being zeroed out | |||
155 | // are just zero. | |||
156 | ||||
157 | // Most compilers can generate this code but the pattern may be missed when | |||
158 | // multiple functions gets inlined. | |||
159 | return (Size + Value - 1) & ~(Value - 1U); | |||
160 | } | |||
161 | ||||
162 | /// If non-zero \p Skew is specified, the return value will be a minimal integer | |||
163 | /// that is greater than or equal to \p Size and equal to \p A * N + \p Skew for | |||
164 | /// some integer N. If \p Skew is larger than \p A, its value is adjusted to '\p | |||
165 | /// Skew mod \p A'. | |||
166 | /// | |||
167 | /// Examples: | |||
168 | /// \code | |||
169 | /// alignTo(5, Align(8), 7) = 7 | |||
170 | /// alignTo(17, Align(8), 1) = 17 | |||
171 | /// alignTo(~0LL, Align(8), 3) = 3 | |||
172 | /// \endcode | |||
173 | inline uint64_t alignTo(uint64_t Size, Align A, uint64_t Skew) { | |||
174 | const uint64_t Value = A.value(); | |||
175 | Skew %= Value; | |||
176 | return ((Size + Value - 1 - Skew) & ~(Value - 1U)) + Skew; | |||
177 | } | |||
178 | ||||
179 | /// Returns a multiple of A needed to store `Size` bytes. | |||
180 | /// Returns `Size` if current alignment is undefined. | |||
181 | inline uint64_t alignTo(uint64_t Size, MaybeAlign A) { | |||
182 | return A ? alignTo(Size, A.getValue()) : Size; | |||
183 | } | |||
184 | ||||
185 | /// Aligns `Addr` to `Alignment` bytes, rounding up. | |||
186 | inline uintptr_t alignAddr(const void *Addr, Align Alignment) { | |||
187 | uintptr_t ArithAddr = reinterpret_cast<uintptr_t>(Addr); | |||
188 | assert(static_cast<uintptr_t>(ArithAddr + Alignment.value() - 1) >=((void)0) | |||
189 | ArithAddr &&((void)0) | |||
190 | "Overflow")((void)0); | |||
191 | return alignTo(ArithAddr, Alignment); | |||
192 | } | |||
193 | ||||
194 | /// Returns the offset to the next integer (mod 2**64) that is greater than | |||
195 | /// or equal to \p Value and is a multiple of \p Align. | |||
196 | inline uint64_t offsetToAlignment(uint64_t Value, Align Alignment) { | |||
197 | return alignTo(Value, Alignment) - Value; | |||
198 | } | |||
199 | ||||
200 | /// Returns the necessary adjustment for aligning `Addr` to `Alignment` | |||
201 | /// bytes, rounding up. | |||
202 | inline uint64_t offsetToAlignedAddr(const void *Addr, Align Alignment) { | |||
203 | return offsetToAlignment(reinterpret_cast<uintptr_t>(Addr), Alignment); | |||
204 | } | |||
205 | ||||
206 | /// Returns the log2 of the alignment. | |||
207 | inline unsigned Log2(Align A) { return A.ShiftValue; } | |||
208 | ||||
209 | /// Returns the alignment that satisfies both alignments. | |||
210 | /// Same semantic as MinAlign. | |||
211 | inline Align commonAlignment(Align A, Align B) { return std::min(A, B); } | |||
212 | ||||
213 | /// Returns the alignment that satisfies both alignments. | |||
214 | /// Same semantic as MinAlign. | |||
215 | inline Align commonAlignment(Align A, uint64_t Offset) { | |||
216 | return Align(MinAlign(A.value(), Offset)); | |||
217 | } | |||
218 | ||||
219 | /// Returns the alignment that satisfies both alignments. | |||
220 | /// Same semantic as MinAlign. | |||
221 | inline MaybeAlign commonAlignment(MaybeAlign A, MaybeAlign B) { | |||
222 | return A && B ? commonAlignment(*A, *B) : A ? A : B; | |||
223 | } | |||
224 | ||||
225 | /// Returns the alignment that satisfies both alignments. | |||
226 | /// Same semantic as MinAlign. | |||
227 | inline MaybeAlign commonAlignment(MaybeAlign A, uint64_t Offset) { | |||
228 | return MaybeAlign(MinAlign((*A).value(), Offset)); | |||
229 | } | |||
230 | ||||
231 | /// Returns a representation of the alignment that encodes undefined as 0. | |||
232 | inline unsigned encode(MaybeAlign A) { return A ? A->ShiftValue + 1 : 0; } | |||
233 | ||||
234 | /// Dual operation of the encode function above. | |||
235 | inline MaybeAlign decodeMaybeAlign(unsigned Value) { | |||
236 | if (Value == 0) | |||
237 | return MaybeAlign(); | |||
238 | Align Out; | |||
239 | Out.ShiftValue = Value - 1; | |||
240 | return Out; | |||
241 | } | |||
242 | ||||
243 | /// Returns a representation of the alignment, the encoded value is positive by | |||
244 | /// definition. | |||
245 | inline unsigned encode(Align A) { return encode(MaybeAlign(A)); } | |||
246 | ||||
247 | /// Comparisons between Align and scalars. Rhs must be positive. | |||
248 | inline bool operator==(Align Lhs, uint64_t Rhs) { | |||
249 | ALIGN_CHECK_ISPOSITIVE(Rhs); | |||
250 | return Lhs.value() == Rhs; | |||
251 | } | |||
252 | inline bool operator!=(Align Lhs, uint64_t Rhs) { | |||
253 | ALIGN_CHECK_ISPOSITIVE(Rhs); | |||
254 | return Lhs.value() != Rhs; | |||
255 | } | |||
256 | inline bool operator<=(Align Lhs, uint64_t Rhs) { | |||
257 | ALIGN_CHECK_ISPOSITIVE(Rhs); | |||
258 | return Lhs.value() <= Rhs; | |||
259 | } | |||
260 | inline bool operator>=(Align Lhs, uint64_t Rhs) { | |||
261 | ALIGN_CHECK_ISPOSITIVE(Rhs); | |||
262 | return Lhs.value() >= Rhs; | |||
263 | } | |||
264 | inline bool operator<(Align Lhs, uint64_t Rhs) { | |||
265 | ALIGN_CHECK_ISPOSITIVE(Rhs); | |||
266 | return Lhs.value() < Rhs; | |||
267 | } | |||
268 | inline bool operator>(Align Lhs, uint64_t Rhs) { | |||
269 | ALIGN_CHECK_ISPOSITIVE(Rhs); | |||
270 | return Lhs.value() > Rhs; | |||
271 | } | |||
272 | ||||
273 | /// Comparisons between MaybeAlign and scalars. | |||
274 | inline bool operator==(MaybeAlign Lhs, uint64_t Rhs) { | |||
275 | return Lhs ? (*Lhs).value() == Rhs : Rhs == 0; | |||
276 | } | |||
277 | inline bool operator!=(MaybeAlign Lhs, uint64_t Rhs) { | |||
278 | return Lhs ? (*Lhs).value() != Rhs : Rhs != 0; | |||
279 | } | |||
280 | ||||
281 | /// Comparisons operators between Align. | |||
282 | inline bool operator==(Align Lhs, Align Rhs) { | |||
283 | return Lhs.ShiftValue == Rhs.ShiftValue; | |||
284 | } | |||
285 | inline bool operator!=(Align Lhs, Align Rhs) { | |||
286 | return Lhs.ShiftValue != Rhs.ShiftValue; | |||
287 | } | |||
288 | inline bool operator<=(Align Lhs, Align Rhs) { | |||
289 | return Lhs.ShiftValue <= Rhs.ShiftValue; | |||
290 | } | |||
291 | inline bool operator>=(Align Lhs, Align Rhs) { | |||
292 | return Lhs.ShiftValue >= Rhs.ShiftValue; | |||
293 | } | |||
294 | inline bool operator<(Align Lhs, Align Rhs) { | |||
295 | return Lhs.ShiftValue < Rhs.ShiftValue; | |||
296 | } | |||
297 | inline bool operator>(Align Lhs, Align Rhs) { | |||
298 | return Lhs.ShiftValue > Rhs.ShiftValue; | |||
299 | } | |||
300 | ||||
301 | // Don't allow relational comparisons with MaybeAlign. | |||
302 | bool operator<=(Align Lhs, MaybeAlign Rhs) = delete; | |||
303 | bool operator>=(Align Lhs, MaybeAlign Rhs) = delete; | |||
304 | bool operator<(Align Lhs, MaybeAlign Rhs) = delete; | |||
305 | bool operator>(Align Lhs, MaybeAlign Rhs) = delete; | |||
306 | ||||
307 | bool operator<=(MaybeAlign Lhs, Align Rhs) = delete; | |||
308 | bool operator>=(MaybeAlign Lhs, Align Rhs) = delete; | |||
309 | bool operator<(MaybeAlign Lhs, Align Rhs) = delete; | |||
310 | bool operator>(MaybeAlign Lhs, Align Rhs) = delete; | |||
311 | ||||
312 | bool operator<=(MaybeAlign Lhs, MaybeAlign Rhs) = delete; | |||
313 | bool operator>=(MaybeAlign Lhs, MaybeAlign Rhs) = delete; | |||
314 | bool operator<(MaybeAlign Lhs, MaybeAlign Rhs) = delete; | |||
315 | bool operator>(MaybeAlign Lhs, MaybeAlign Rhs) = delete; | |||
316 | ||||
317 | inline Align operator*(Align Lhs, uint64_t Rhs) { | |||
318 | assert(Rhs > 0 && "Rhs must be positive")((void)0); | |||
319 | return Align(Lhs.value() * Rhs); | |||
320 | } | |||
321 | ||||
322 | inline MaybeAlign operator*(MaybeAlign Lhs, uint64_t Rhs) { | |||
323 | assert(Rhs > 0 && "Rhs must be positive")((void)0); | |||
324 | return Lhs ? Lhs.getValue() * Rhs : MaybeAlign(); | |||
325 | } | |||
326 | ||||
327 | inline Align operator/(Align Lhs, uint64_t Divisor) { | |||
328 | assert(llvm::isPowerOf2_64(Divisor) &&((void)0) | |||
329 | "Divisor must be positive and a power of 2")((void)0); | |||
330 | assert(Lhs != 1 && "Can't halve byte alignment")((void)0); | |||
331 | return Align(Lhs.value() / Divisor); | |||
332 | } | |||
333 | ||||
334 | inline MaybeAlign operator/(MaybeAlign Lhs, uint64_t Divisor) { | |||
335 | assert(llvm::isPowerOf2_64(Divisor) &&((void)0) | |||
336 | "Divisor must be positive and a power of 2")((void)0); | |||
337 | return Lhs ? Lhs.getValue() / Divisor : MaybeAlign(); | |||
338 | } | |||
339 | ||||
340 | inline Align max(MaybeAlign Lhs, Align Rhs) { | |||
341 | return Lhs && *Lhs > Rhs ? *Lhs : Rhs; | |||
342 | } | |||
343 | ||||
344 | inline Align max(Align Lhs, MaybeAlign Rhs) { | |||
345 | return Rhs && *Rhs > Lhs ? *Rhs : Lhs; | |||
346 | } | |||
347 | ||||
348 | #ifndef NDEBUG1 | |||
349 | // For usage in LLVM_DEBUG macros. | |||
350 | inline std::string DebugStr(const Align &A) { | |||
351 | return std::to_string(A.value()); | |||
352 | } | |||
353 | // For usage in LLVM_DEBUG macros. | |||
354 | inline std::string DebugStr(const MaybeAlign &MA) { | |||
355 | if (MA) | |||
356 | return std::to_string(MA->value()); | |||
357 | return "None"; | |||
358 | } | |||
359 | #endif // NDEBUG | |||
360 | ||||
361 | #undef ALIGN_CHECK_ISPOSITIVE | |||
362 | ||||
363 | } // namespace llvm | |||
364 | ||||
365 | #endif // LLVM_SUPPORT_ALIGNMENT_H_ |