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 | //===- Attributor.cpp - Module-wide attribute 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 | // This file implements an interprocedural pass that deduces and/or propagates | ||||||||
10 | // attributes. This is done in an abstract interpretation style fixpoint | ||||||||
11 | // iteration. See the Attributor.h file comment and the class descriptions in | ||||||||
12 | // that file for more information. | ||||||||
13 | // | ||||||||
14 | //===----------------------------------------------------------------------===// | ||||||||
15 | |||||||||
16 | #include "llvm/Transforms/IPO/Attributor.h" | ||||||||
17 | |||||||||
18 | #include "llvm/ADT/GraphTraits.h" | ||||||||
19 | #include "llvm/ADT/PointerIntPair.h" | ||||||||
20 | #include "llvm/ADT/STLExtras.h" | ||||||||
21 | #include "llvm/ADT/Statistic.h" | ||||||||
22 | #include "llvm/ADT/TinyPtrVector.h" | ||||||||
23 | #include "llvm/Analysis/InlineCost.h" | ||||||||
24 | #include "llvm/Analysis/LazyValueInfo.h" | ||||||||
25 | #include "llvm/Analysis/MemorySSAUpdater.h" | ||||||||
26 | #include "llvm/Analysis/MustExecute.h" | ||||||||
27 | #include "llvm/Analysis/ValueTracking.h" | ||||||||
28 | #include "llvm/IR/Attributes.h" | ||||||||
29 | #include "llvm/IR/Constant.h" | ||||||||
30 | #include "llvm/IR/Constants.h" | ||||||||
31 | #include "llvm/IR/GlobalValue.h" | ||||||||
32 | #include "llvm/IR/GlobalVariable.h" | ||||||||
33 | #include "llvm/IR/IRBuilder.h" | ||||||||
34 | #include "llvm/IR/Instruction.h" | ||||||||
35 | #include "llvm/IR/Instructions.h" | ||||||||
36 | #include "llvm/IR/IntrinsicInst.h" | ||||||||
37 | #include "llvm/IR/NoFolder.h" | ||||||||
38 | #include "llvm/IR/ValueHandle.h" | ||||||||
39 | #include "llvm/IR/Verifier.h" | ||||||||
40 | #include "llvm/InitializePasses.h" | ||||||||
41 | #include "llvm/Support/Casting.h" | ||||||||
42 | #include "llvm/Support/CommandLine.h" | ||||||||
43 | #include "llvm/Support/Debug.h" | ||||||||
44 | #include "llvm/Support/DebugCounter.h" | ||||||||
45 | #include "llvm/Support/FileSystem.h" | ||||||||
46 | #include "llvm/Support/GraphWriter.h" | ||||||||
47 | #include "llvm/Support/raw_ostream.h" | ||||||||
48 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | ||||||||
49 | #include "llvm/Transforms/Utils/Cloning.h" | ||||||||
50 | #include "llvm/Transforms/Utils/Local.h" | ||||||||
51 | |||||||||
52 | #include <cassert> | ||||||||
53 | #include <string> | ||||||||
54 | |||||||||
55 | using namespace llvm; | ||||||||
56 | |||||||||
57 | #define DEBUG_TYPE"attributor" "attributor" | ||||||||
58 | |||||||||
59 | DEBUG_COUNTER(ManifestDBGCounter, "attributor-manifest",static const unsigned ManifestDBGCounter = DebugCounter::registerCounter ("attributor-manifest", "Determine what attributes are manifested in the IR" ) | ||||||||
60 | "Determine what attributes are manifested in the IR")static const unsigned ManifestDBGCounter = DebugCounter::registerCounter ("attributor-manifest", "Determine what attributes are manifested in the IR" ); | ||||||||
61 | |||||||||
62 | STATISTIC(NumFnDeleted, "Number of function deleted")static llvm::Statistic NumFnDeleted = {"attributor", "NumFnDeleted" , "Number of function deleted"}; | ||||||||
63 | STATISTIC(NumFnWithExactDefinition,static llvm::Statistic NumFnWithExactDefinition = {"attributor" , "NumFnWithExactDefinition", "Number of functions with exact definitions" } | ||||||||
64 | "Number of functions with exact definitions")static llvm::Statistic NumFnWithExactDefinition = {"attributor" , "NumFnWithExactDefinition", "Number of functions with exact definitions" }; | ||||||||
65 | STATISTIC(NumFnWithoutExactDefinition,static llvm::Statistic NumFnWithoutExactDefinition = {"attributor" , "NumFnWithoutExactDefinition", "Number of functions without exact definitions" } | ||||||||
66 | "Number of functions without exact definitions")static llvm::Statistic NumFnWithoutExactDefinition = {"attributor" , "NumFnWithoutExactDefinition", "Number of functions without exact definitions" }; | ||||||||
67 | STATISTIC(NumFnShallowWrappersCreated, "Number of shallow wrappers created")static llvm::Statistic NumFnShallowWrappersCreated = {"attributor" , "NumFnShallowWrappersCreated", "Number of shallow wrappers created" }; | ||||||||
68 | STATISTIC(NumAttributesTimedOut,static llvm::Statistic NumAttributesTimedOut = {"attributor", "NumAttributesTimedOut", "Number of abstract attributes timed out before fixpoint" } | ||||||||
69 | "Number of abstract attributes timed out before fixpoint")static llvm::Statistic NumAttributesTimedOut = {"attributor", "NumAttributesTimedOut", "Number of abstract attributes timed out before fixpoint" }; | ||||||||
70 | STATISTIC(NumAttributesValidFixpoint,static llvm::Statistic NumAttributesValidFixpoint = {"attributor" , "NumAttributesValidFixpoint", "Number of abstract attributes in a valid fixpoint state" } | ||||||||
71 | "Number of abstract attributes in a valid fixpoint state")static llvm::Statistic NumAttributesValidFixpoint = {"attributor" , "NumAttributesValidFixpoint", "Number of abstract attributes in a valid fixpoint state" }; | ||||||||
72 | STATISTIC(NumAttributesManifested,static llvm::Statistic NumAttributesManifested = {"attributor" , "NumAttributesManifested", "Number of abstract attributes manifested in IR" } | ||||||||
73 | "Number of abstract attributes manifested in IR")static llvm::Statistic NumAttributesManifested = {"attributor" , "NumAttributesManifested", "Number of abstract attributes manifested in IR" }; | ||||||||
74 | |||||||||
75 | // TODO: Determine a good default value. | ||||||||
76 | // | ||||||||
77 | // In the LLVM-TS and SPEC2006, 32 seems to not induce compile time overheads | ||||||||
78 | // (when run with the first 5 abstract attributes). The results also indicate | ||||||||
79 | // that we never reach 32 iterations but always find a fixpoint sooner. | ||||||||
80 | // | ||||||||
81 | // This will become more evolved once we perform two interleaved fixpoint | ||||||||
82 | // iterations: bottom-up and top-down. | ||||||||
83 | static cl::opt<unsigned> | ||||||||
84 | SetFixpointIterations("attributor-max-iterations", cl::Hidden, | ||||||||
85 | cl::desc("Maximal number of fixpoint iterations."), | ||||||||
86 | cl::init(32)); | ||||||||
87 | |||||||||
88 | static cl::opt<unsigned, true> MaxInitializationChainLengthX( | ||||||||
89 | "attributor-max-initialization-chain-length", cl::Hidden, | ||||||||
90 | cl::desc( | ||||||||
91 | "Maximal number of chained initializations (to avoid stack overflows)"), | ||||||||
92 | cl::location(MaxInitializationChainLength), cl::init(1024)); | ||||||||
93 | unsigned llvm::MaxInitializationChainLength; | ||||||||
94 | |||||||||
95 | static cl::opt<bool> VerifyMaxFixpointIterations( | ||||||||
96 | "attributor-max-iterations-verify", cl::Hidden, | ||||||||
97 | cl::desc("Verify that max-iterations is a tight bound for a fixpoint"), | ||||||||
98 | cl::init(false)); | ||||||||
99 | |||||||||
100 | static cl::opt<bool> AnnotateDeclarationCallSites( | ||||||||
101 | "attributor-annotate-decl-cs", cl::Hidden, | ||||||||
102 | cl::desc("Annotate call sites of function declarations."), cl::init(false)); | ||||||||
103 | |||||||||
104 | static cl::opt<bool> EnableHeapToStack("enable-heap-to-stack-conversion", | ||||||||
105 | cl::init(true), cl::Hidden); | ||||||||
106 | |||||||||
107 | static cl::opt<bool> | ||||||||
108 | AllowShallowWrappers("attributor-allow-shallow-wrappers", cl::Hidden, | ||||||||
109 | cl::desc("Allow the Attributor to create shallow " | ||||||||
110 | "wrappers for non-exact definitions."), | ||||||||
111 | cl::init(false)); | ||||||||
112 | |||||||||
113 | static cl::opt<bool> | ||||||||
114 | AllowDeepWrapper("attributor-allow-deep-wrappers", cl::Hidden, | ||||||||
115 | cl::desc("Allow the Attributor to use IP information " | ||||||||
116 | "derived from non-exact functions via cloning"), | ||||||||
117 | cl::init(false)); | ||||||||
118 | |||||||||
119 | // These options can only used for debug builds. | ||||||||
120 | #ifndef NDEBUG1 | ||||||||
121 | static cl::list<std::string> | ||||||||
122 | SeedAllowList("attributor-seed-allow-list", cl::Hidden, | ||||||||
123 | cl::desc("Comma seperated list of attribute names that are " | ||||||||
124 | "allowed to be seeded."), | ||||||||
125 | cl::ZeroOrMore, cl::CommaSeparated); | ||||||||
126 | |||||||||
127 | static cl::list<std::string> FunctionSeedAllowList( | ||||||||
128 | "attributor-function-seed-allow-list", cl::Hidden, | ||||||||
129 | cl::desc("Comma seperated list of function names that are " | ||||||||
130 | "allowed to be seeded."), | ||||||||
131 | cl::ZeroOrMore, cl::CommaSeparated); | ||||||||
132 | #endif | ||||||||
133 | |||||||||
134 | static cl::opt<bool> | ||||||||
135 | DumpDepGraph("attributor-dump-dep-graph", cl::Hidden, | ||||||||
136 | cl::desc("Dump the dependency graph to dot files."), | ||||||||
137 | cl::init(false)); | ||||||||
138 | |||||||||
139 | static cl::opt<std::string> DepGraphDotFileNamePrefix( | ||||||||
140 | "attributor-depgraph-dot-filename-prefix", cl::Hidden, | ||||||||
141 | cl::desc("The prefix used for the CallGraph dot file names.")); | ||||||||
142 | |||||||||
143 | static cl::opt<bool> ViewDepGraph("attributor-view-dep-graph", cl::Hidden, | ||||||||
144 | cl::desc("View the dependency graph."), | ||||||||
145 | cl::init(false)); | ||||||||
146 | |||||||||
147 | static cl::opt<bool> PrintDependencies("attributor-print-dep", cl::Hidden, | ||||||||
148 | cl::desc("Print attribute dependencies"), | ||||||||
149 | cl::init(false)); | ||||||||
150 | |||||||||
151 | static cl::opt<bool> EnableCallSiteSpecific( | ||||||||
152 | "attributor-enable-call-site-specific-deduction", cl::Hidden, | ||||||||
153 | cl::desc("Allow the Attributor to do call site specific analysis"), | ||||||||
154 | cl::init(false)); | ||||||||
155 | |||||||||
156 | static cl::opt<bool> | ||||||||
157 | PrintCallGraph("attributor-print-call-graph", cl::Hidden, | ||||||||
158 | cl::desc("Print Attributor's internal call graph"), | ||||||||
159 | cl::init(false)); | ||||||||
160 | |||||||||
161 | static cl::opt<bool> SimplifyAllLoads("attributor-simplify-all-loads", | ||||||||
162 | cl::Hidden, | ||||||||
163 | cl::desc("Try to simplify all loads."), | ||||||||
164 | cl::init(true)); | ||||||||
165 | |||||||||
166 | /// Logic operators for the change status enum class. | ||||||||
167 | /// | ||||||||
168 | ///{ | ||||||||
169 | ChangeStatus llvm::operator|(ChangeStatus L, ChangeStatus R) { | ||||||||
170 | return L == ChangeStatus::CHANGED ? L : R; | ||||||||
171 | } | ||||||||
172 | ChangeStatus &llvm::operator|=(ChangeStatus &L, ChangeStatus R) { | ||||||||
173 | L = L | R; | ||||||||
174 | return L; | ||||||||
175 | } | ||||||||
176 | ChangeStatus llvm::operator&(ChangeStatus L, ChangeStatus R) { | ||||||||
177 | return L == ChangeStatus::UNCHANGED ? L : R; | ||||||||
178 | } | ||||||||
179 | ChangeStatus &llvm::operator&=(ChangeStatus &L, ChangeStatus R) { | ||||||||
180 | L = L & R; | ||||||||
181 | return L; | ||||||||
182 | } | ||||||||
183 | ///} | ||||||||
184 | |||||||||
185 | bool AA::isDynamicallyUnique(Attributor &A, const AbstractAttribute &QueryingAA, | ||||||||
186 | const Value &V) { | ||||||||
187 | if (auto *C = dyn_cast<Constant>(&V)) | ||||||||
188 | return !C->isThreadDependent(); | ||||||||
189 | // TODO: Inspect and cache more complex instructions. | ||||||||
190 | if (auto *CB = dyn_cast<CallBase>(&V)) | ||||||||
191 | return CB->getNumOperands() == 0 && !CB->mayHaveSideEffects() && | ||||||||
192 | !CB->mayReadFromMemory(); | ||||||||
193 | const Function *Scope = nullptr; | ||||||||
194 | if (auto *I = dyn_cast<Instruction>(&V)) | ||||||||
195 | Scope = I->getFunction(); | ||||||||
196 | if (auto *A = dyn_cast<Argument>(&V)) | ||||||||
197 | Scope = A->getParent(); | ||||||||
198 | if (!Scope) | ||||||||
199 | return false; | ||||||||
200 | auto &NoRecurseAA = A.getAAFor<AANoRecurse>( | ||||||||
201 | QueryingAA, IRPosition::function(*Scope), DepClassTy::OPTIONAL); | ||||||||
202 | return NoRecurseAA.isAssumedNoRecurse(); | ||||||||
203 | } | ||||||||
204 | |||||||||
205 | Constant *AA::getInitialValueForObj(Value &Obj, Type &Ty) { | ||||||||
206 | if (isa<AllocaInst>(Obj)) | ||||||||
207 | return UndefValue::get(&Ty); | ||||||||
208 | auto *GV = dyn_cast<GlobalVariable>(&Obj); | ||||||||
209 | if (!GV || !GV->hasLocalLinkage()) | ||||||||
210 | return nullptr; | ||||||||
211 | if (!GV->hasInitializer()) | ||||||||
212 | return UndefValue::get(&Ty); | ||||||||
213 | return dyn_cast_or_null<Constant>(getWithType(*GV->getInitializer(), Ty)); | ||||||||
214 | } | ||||||||
215 | |||||||||
216 | bool AA::isValidInScope(const Value &V, const Function *Scope) { | ||||||||
217 | if (isa<Constant>(V)) | ||||||||
218 | return true; | ||||||||
219 | if (auto *I = dyn_cast<Instruction>(&V)) | ||||||||
220 | return I->getFunction() == Scope; | ||||||||
221 | if (auto *A = dyn_cast<Argument>(&V)) | ||||||||
222 | return A->getParent() == Scope; | ||||||||
223 | return false; | ||||||||
224 | } | ||||||||
225 | |||||||||
226 | bool AA::isValidAtPosition(const Value &V, const Instruction &CtxI, | ||||||||
227 | InformationCache &InfoCache) { | ||||||||
228 | if (isa<Constant>(V)) | ||||||||
229 | return true; | ||||||||
230 | const Function *Scope = CtxI.getFunction(); | ||||||||
231 | if (auto *A = dyn_cast<Argument>(&V)) | ||||||||
232 | return A->getParent() == Scope; | ||||||||
233 | if (auto *I = dyn_cast<Instruction>(&V)) | ||||||||
234 | if (I->getFunction() == Scope) { | ||||||||
235 | const DominatorTree *DT = | ||||||||
236 | InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>(*Scope); | ||||||||
237 | return DT && DT->dominates(I, &CtxI); | ||||||||
238 | } | ||||||||
239 | return false; | ||||||||
240 | } | ||||||||
241 | |||||||||
242 | Value *AA::getWithType(Value &V, Type &Ty) { | ||||||||
243 | if (V.getType() == &Ty) | ||||||||
244 | return &V; | ||||||||
245 | if (isa<PoisonValue>(V)) | ||||||||
246 | return PoisonValue::get(&Ty); | ||||||||
247 | if (isa<UndefValue>(V)) | ||||||||
248 | return UndefValue::get(&Ty); | ||||||||
249 | if (auto *C = dyn_cast<Constant>(&V)) { | ||||||||
250 | if (C->isNullValue()) | ||||||||
251 | return Constant::getNullValue(&Ty); | ||||||||
252 | if (C->getType()->isPointerTy() && Ty.isPointerTy()) | ||||||||
253 | return ConstantExpr::getPointerCast(C, &Ty); | ||||||||
254 | if (C->getType()->getPrimitiveSizeInBits() >= Ty.getPrimitiveSizeInBits()) { | ||||||||
255 | if (C->getType()->isIntegerTy() && Ty.isIntegerTy()) | ||||||||
256 | return ConstantExpr::getTrunc(C, &Ty, /* OnlyIfReduced */ true); | ||||||||
257 | if (C->getType()->isFloatingPointTy() && Ty.isFloatingPointTy()) | ||||||||
258 | return ConstantExpr::getFPTrunc(C, &Ty, /* OnlyIfReduced */ true); | ||||||||
259 | } | ||||||||
260 | } | ||||||||
261 | return nullptr; | ||||||||
262 | } | ||||||||
263 | |||||||||
264 | Optional<Value *> | ||||||||
265 | AA::combineOptionalValuesInAAValueLatice(const Optional<Value *> &A, | ||||||||
266 | const Optional<Value *> &B, Type *Ty) { | ||||||||
267 | if (A == B) | ||||||||
268 | return A; | ||||||||
269 | if (!B.hasValue()) | ||||||||
270 | return A; | ||||||||
271 | if (*B == nullptr) | ||||||||
272 | return nullptr; | ||||||||
273 | if (!A.hasValue()) | ||||||||
274 | return Ty ? getWithType(**B, *Ty) : nullptr; | ||||||||
275 | if (*A == nullptr) | ||||||||
276 | return nullptr; | ||||||||
277 | if (!Ty) | ||||||||
278 | Ty = (*A)->getType(); | ||||||||
279 | if (isa_and_nonnull<UndefValue>(*A)) | ||||||||
280 | return getWithType(**B, *Ty); | ||||||||
281 | if (isa<UndefValue>(*B)) | ||||||||
282 | return A; | ||||||||
283 | if (*A && *B && *A == getWithType(**B, *Ty)) | ||||||||
284 | return A; | ||||||||
285 | return nullptr; | ||||||||
286 | } | ||||||||
287 | |||||||||
288 | bool AA::getPotentialCopiesOfStoredValue( | ||||||||
289 | Attributor &A, StoreInst &SI, SmallSetVector<Value *, 4> &PotentialCopies, | ||||||||
290 | const AbstractAttribute &QueryingAA, bool &UsedAssumedInformation) { | ||||||||
291 | |||||||||
292 | Value &Ptr = *SI.getPointerOperand(); | ||||||||
293 | SmallVector<Value *, 8> Objects; | ||||||||
294 | if (!AA::getAssumedUnderlyingObjects(A, Ptr, Objects, QueryingAA, &SI)) { | ||||||||
295 | LLVM_DEBUG(do { } while (false) | ||||||||
296 | dbgs() << "Underlying objects stored into could not be determined\n";)do { } while (false); | ||||||||
297 | return false; | ||||||||
298 | } | ||||||||
299 | |||||||||
300 | SmallVector<const AAPointerInfo *> PIs; | ||||||||
301 | SmallVector<Value *> NewCopies; | ||||||||
302 | |||||||||
303 | for (Value *Obj : Objects) { | ||||||||
304 | LLVM_DEBUG(dbgs() << "Visit underlying object " << *Obj << "\n")do { } while (false); | ||||||||
305 | if (isa<UndefValue>(Obj)) | ||||||||
306 | continue; | ||||||||
307 | if (isa<ConstantPointerNull>(Obj)) { | ||||||||
308 | // A null pointer access can be undefined but any offset from null may | ||||||||
309 | // be OK. We do not try to optimize the latter. | ||||||||
310 | if (!NullPointerIsDefined(SI.getFunction(), | ||||||||
311 | Ptr.getType()->getPointerAddressSpace()) && | ||||||||
312 | A.getAssumedSimplified(Ptr, QueryingAA, UsedAssumedInformation) == | ||||||||
313 | Obj) | ||||||||
314 | continue; | ||||||||
315 | LLVM_DEBUG(do { } while (false) | ||||||||
316 | dbgs() << "Underlying object is a valid nullptr, giving up.\n";)do { } while (false); | ||||||||
317 | return false; | ||||||||
318 | } | ||||||||
319 | if (!isa<AllocaInst>(Obj) && !isa<GlobalVariable>(Obj)) { | ||||||||
320 | LLVM_DEBUG(dbgs() << "Underlying object is not supported yet: " << *Objdo { } while (false) | ||||||||
321 | << "\n";)do { } while (false); | ||||||||
322 | return false; | ||||||||
323 | } | ||||||||
324 | if (auto *GV = dyn_cast<GlobalVariable>(Obj)) | ||||||||
325 | if (!GV->hasLocalLinkage()) { | ||||||||
326 | LLVM_DEBUG(dbgs() << "Underlying object is global with external "do { } while (false) | ||||||||
327 | "linkage, not supported yet: "do { } while (false) | ||||||||
328 | << *Obj << "\n";)do { } while (false); | ||||||||
329 | return false; | ||||||||
330 | } | ||||||||
331 | |||||||||
332 | auto CheckAccess = [&](const AAPointerInfo::Access &Acc, bool IsExact) { | ||||||||
333 | if (!Acc.isRead()) | ||||||||
334 | return true; | ||||||||
335 | auto *LI = dyn_cast<LoadInst>(Acc.getRemoteInst()); | ||||||||
336 | if (!LI) { | ||||||||
337 | LLVM_DEBUG(dbgs() << "Underlying object read through a non-load "do { } while (false) | ||||||||
338 | "instruction not supported yet: "do { } while (false) | ||||||||
339 | << *Acc.getRemoteInst() << "\n";)do { } while (false); | ||||||||
340 | return false; | ||||||||
341 | } | ||||||||
342 | NewCopies.push_back(LI); | ||||||||
343 | return true; | ||||||||
344 | }; | ||||||||
345 | |||||||||
346 | auto &PI = A.getAAFor<AAPointerInfo>(QueryingAA, IRPosition::value(*Obj), | ||||||||
347 | DepClassTy::NONE); | ||||||||
348 | if (!PI.forallInterferingAccesses(SI, CheckAccess)) { | ||||||||
349 | LLVM_DEBUG(do { } while (false) | ||||||||
350 | dbgs()do { } while (false) | ||||||||
351 | << "Failed to verify all interfering accesses for underlying object: "do { } while (false) | ||||||||
352 | << *Obj << "\n")do { } while (false); | ||||||||
353 | return false; | ||||||||
354 | } | ||||||||
355 | PIs.push_back(&PI); | ||||||||
356 | } | ||||||||
357 | |||||||||
358 | for (auto *PI : PIs) { | ||||||||
359 | if (!PI->getState().isAtFixpoint()) | ||||||||
360 | UsedAssumedInformation = true; | ||||||||
361 | A.recordDependence(*PI, QueryingAA, DepClassTy::OPTIONAL); | ||||||||
362 | } | ||||||||
363 | PotentialCopies.insert(NewCopies.begin(), NewCopies.end()); | ||||||||
364 | |||||||||
365 | return true; | ||||||||
366 | } | ||||||||
367 | |||||||||
368 | /// Return true if \p New is equal or worse than \p Old. | ||||||||
369 | static bool isEqualOrWorse(const Attribute &New, const Attribute &Old) { | ||||||||
370 | if (!Old.isIntAttribute()) | ||||||||
371 | return true; | ||||||||
372 | |||||||||
373 | return Old.getValueAsInt() >= New.getValueAsInt(); | ||||||||
374 | } | ||||||||
375 | |||||||||
376 | /// Return true if the information provided by \p Attr was added to the | ||||||||
377 | /// attribute list \p Attrs. This is only the case if it was not already present | ||||||||
378 | /// in \p Attrs at the position describe by \p PK and \p AttrIdx. | ||||||||
379 | static bool addIfNotExistent(LLVMContext &Ctx, const Attribute &Attr, | ||||||||
380 | AttributeList &Attrs, int AttrIdx, | ||||||||
381 | bool ForceReplace = false) { | ||||||||
382 | |||||||||
383 | if (Attr.isEnumAttribute()) { | ||||||||
384 | Attribute::AttrKind Kind = Attr.getKindAsEnum(); | ||||||||
385 | if (Attrs.hasAttribute(AttrIdx, Kind)) | ||||||||
386 | if (!ForceReplace && | ||||||||
387 | isEqualOrWorse(Attr, Attrs.getAttribute(AttrIdx, Kind))) | ||||||||
388 | return false; | ||||||||
389 | Attrs = Attrs.addAttribute(Ctx, AttrIdx, Attr); | ||||||||
390 | return true; | ||||||||
391 | } | ||||||||
392 | if (Attr.isStringAttribute()) { | ||||||||
393 | StringRef Kind = Attr.getKindAsString(); | ||||||||
394 | if (Attrs.hasAttribute(AttrIdx, Kind)) | ||||||||
395 | if (!ForceReplace && | ||||||||
396 | isEqualOrWorse(Attr, Attrs.getAttribute(AttrIdx, Kind))) | ||||||||
397 | return false; | ||||||||
398 | Attrs = Attrs.addAttribute(Ctx, AttrIdx, Attr); | ||||||||
399 | return true; | ||||||||
400 | } | ||||||||
401 | if (Attr.isIntAttribute()) { | ||||||||
402 | Attribute::AttrKind Kind = Attr.getKindAsEnum(); | ||||||||
403 | if (Attrs.hasAttribute(AttrIdx, Kind)) | ||||||||
404 | if (!ForceReplace && | ||||||||
405 | isEqualOrWorse(Attr, Attrs.getAttribute(AttrIdx, Kind))) | ||||||||
406 | return false; | ||||||||
407 | Attrs = Attrs.removeAttribute(Ctx, AttrIdx, Kind); | ||||||||
408 | Attrs = Attrs.addAttribute(Ctx, AttrIdx, Attr); | ||||||||
409 | return true; | ||||||||
410 | } | ||||||||
411 | |||||||||
412 | llvm_unreachable("Expected enum or string attribute!")__builtin_unreachable(); | ||||||||
413 | } | ||||||||
414 | |||||||||
415 | Argument *IRPosition::getAssociatedArgument() const { | ||||||||
416 | if (getPositionKind() == IRP_ARGUMENT) | ||||||||
417 | return cast<Argument>(&getAnchorValue()); | ||||||||
418 | |||||||||
419 | // Not an Argument and no argument number means this is not a call site | ||||||||
420 | // argument, thus we cannot find a callback argument to return. | ||||||||
421 | int ArgNo = getCallSiteArgNo(); | ||||||||
422 | if (ArgNo < 0) | ||||||||
423 | return nullptr; | ||||||||
424 | |||||||||
425 | // Use abstract call sites to make the connection between the call site | ||||||||
426 | // values and the ones in callbacks. If a callback was found that makes use | ||||||||
427 | // of the underlying call site operand, we want the corresponding callback | ||||||||
428 | // callee argument and not the direct callee argument. | ||||||||
429 | Optional<Argument *> CBCandidateArg; | ||||||||
430 | SmallVector<const Use *, 4> CallbackUses; | ||||||||
431 | const auto &CB = cast<CallBase>(getAnchorValue()); | ||||||||
432 | AbstractCallSite::getCallbackUses(CB, CallbackUses); | ||||||||
433 | for (const Use *U : CallbackUses) { | ||||||||
434 | AbstractCallSite ACS(U); | ||||||||
435 | assert(ACS && ACS.isCallbackCall())((void)0); | ||||||||
436 | if (!ACS.getCalledFunction()) | ||||||||
437 | continue; | ||||||||
438 | |||||||||
439 | for (unsigned u = 0, e = ACS.getNumArgOperands(); u < e; u++) { | ||||||||
440 | |||||||||
441 | // Test if the underlying call site operand is argument number u of the | ||||||||
442 | // callback callee. | ||||||||
443 | if (ACS.getCallArgOperandNo(u) != ArgNo) | ||||||||
444 | continue; | ||||||||
445 | |||||||||
446 | assert(ACS.getCalledFunction()->arg_size() > u &&((void)0) | ||||||||
447 | "ACS mapped into var-args arguments!")((void)0); | ||||||||
448 | if (CBCandidateArg.hasValue()) { | ||||||||
449 | CBCandidateArg = nullptr; | ||||||||
450 | break; | ||||||||
451 | } | ||||||||
452 | CBCandidateArg = ACS.getCalledFunction()->getArg(u); | ||||||||
453 | } | ||||||||
454 | } | ||||||||
455 | |||||||||
456 | // If we found a unique callback candidate argument, return it. | ||||||||
457 | if (CBCandidateArg.hasValue() && CBCandidateArg.getValue()) | ||||||||
458 | return CBCandidateArg.getValue(); | ||||||||
459 | |||||||||
460 | // If no callbacks were found, or none used the underlying call site operand | ||||||||
461 | // exclusively, use the direct callee argument if available. | ||||||||
462 | const Function *Callee = CB.getCalledFunction(); | ||||||||
463 | if (Callee && Callee->arg_size() > unsigned(ArgNo)) | ||||||||
464 | return Callee->getArg(ArgNo); | ||||||||
465 | |||||||||
466 | return nullptr; | ||||||||
467 | } | ||||||||
468 | |||||||||
469 | ChangeStatus AbstractAttribute::update(Attributor &A) { | ||||||||
470 | ChangeStatus HasChanged = ChangeStatus::UNCHANGED; | ||||||||
471 | if (getState().isAtFixpoint()) | ||||||||
472 | return HasChanged; | ||||||||
473 | |||||||||
474 | LLVM_DEBUG(dbgs() << "[Attributor] Update: " << *this << "\n")do { } while (false); | ||||||||
475 | |||||||||
476 | HasChanged = updateImpl(A); | ||||||||
477 | |||||||||
478 | LLVM_DEBUG(dbgs() << "[Attributor] Update " << HasChanged << " " << *thisdo { } while (false) | ||||||||
479 | << "\n")do { } while (false); | ||||||||
480 | |||||||||
481 | return HasChanged; | ||||||||
482 | } | ||||||||
483 | |||||||||
484 | ChangeStatus | ||||||||
485 | IRAttributeManifest::manifestAttrs(Attributor &A, const IRPosition &IRP, | ||||||||
486 | const ArrayRef<Attribute> &DeducedAttrs, | ||||||||
487 | bool ForceReplace) { | ||||||||
488 | Function *ScopeFn = IRP.getAnchorScope(); | ||||||||
489 | IRPosition::Kind PK = IRP.getPositionKind(); | ||||||||
490 | |||||||||
491 | // In the following some generic code that will manifest attributes in | ||||||||
492 | // DeducedAttrs if they improve the current IR. Due to the different | ||||||||
493 | // annotation positions we use the underlying AttributeList interface. | ||||||||
494 | |||||||||
495 | AttributeList Attrs; | ||||||||
496 | switch (PK) { | ||||||||
497 | case IRPosition::IRP_INVALID: | ||||||||
498 | case IRPosition::IRP_FLOAT: | ||||||||
499 | return ChangeStatus::UNCHANGED; | ||||||||
500 | case IRPosition::IRP_ARGUMENT: | ||||||||
501 | case IRPosition::IRP_FUNCTION: | ||||||||
502 | case IRPosition::IRP_RETURNED: | ||||||||
503 | Attrs = ScopeFn->getAttributes(); | ||||||||
504 | break; | ||||||||
505 | case IRPosition::IRP_CALL_SITE: | ||||||||
506 | case IRPosition::IRP_CALL_SITE_RETURNED: | ||||||||
507 | case IRPosition::IRP_CALL_SITE_ARGUMENT: | ||||||||
508 | Attrs = cast<CallBase>(IRP.getAnchorValue()).getAttributes(); | ||||||||
509 | break; | ||||||||
510 | } | ||||||||
511 | |||||||||
512 | ChangeStatus HasChanged = ChangeStatus::UNCHANGED; | ||||||||
513 | LLVMContext &Ctx = IRP.getAnchorValue().getContext(); | ||||||||
514 | for (const Attribute &Attr : DeducedAttrs) { | ||||||||
515 | if (!addIfNotExistent(Ctx, Attr, Attrs, IRP.getAttrIdx(), ForceReplace)) | ||||||||
516 | continue; | ||||||||
517 | |||||||||
518 | HasChanged = ChangeStatus::CHANGED; | ||||||||
519 | } | ||||||||
520 | |||||||||
521 | if (HasChanged == ChangeStatus::UNCHANGED) | ||||||||
522 | return HasChanged; | ||||||||
523 | |||||||||
524 | switch (PK) { | ||||||||
525 | case IRPosition::IRP_ARGUMENT: | ||||||||
526 | case IRPosition::IRP_FUNCTION: | ||||||||
527 | case IRPosition::IRP_RETURNED: | ||||||||
528 | ScopeFn->setAttributes(Attrs); | ||||||||
529 | break; | ||||||||
530 | case IRPosition::IRP_CALL_SITE: | ||||||||
531 | case IRPosition::IRP_CALL_SITE_RETURNED: | ||||||||
532 | case IRPosition::IRP_CALL_SITE_ARGUMENT: | ||||||||
533 | cast<CallBase>(IRP.getAnchorValue()).setAttributes(Attrs); | ||||||||
534 | break; | ||||||||
535 | case IRPosition::IRP_INVALID: | ||||||||
536 | case IRPosition::IRP_FLOAT: | ||||||||
537 | break; | ||||||||
538 | } | ||||||||
539 | |||||||||
540 | return HasChanged; | ||||||||
541 | } | ||||||||
542 | |||||||||
543 | const IRPosition IRPosition::EmptyKey(DenseMapInfo<void *>::getEmptyKey()); | ||||||||
544 | const IRPosition | ||||||||
545 | IRPosition::TombstoneKey(DenseMapInfo<void *>::getTombstoneKey()); | ||||||||
546 | |||||||||
547 | SubsumingPositionIterator::SubsumingPositionIterator(const IRPosition &IRP) { | ||||||||
548 | IRPositions.emplace_back(IRP); | ||||||||
549 | |||||||||
550 | // Helper to determine if operand bundles on a call site are benin or | ||||||||
551 | // potentially problematic. We handle only llvm.assume for now. | ||||||||
552 | auto CanIgnoreOperandBundles = [](const CallBase &CB) { | ||||||||
553 | return (isa<IntrinsicInst>(CB) && | ||||||||
554 | cast<IntrinsicInst>(CB).getIntrinsicID() == Intrinsic ::assume); | ||||||||
555 | }; | ||||||||
556 | |||||||||
557 | const auto *CB = dyn_cast<CallBase>(&IRP.getAnchorValue()); | ||||||||
558 | switch (IRP.getPositionKind()) { | ||||||||
559 | case IRPosition::IRP_INVALID: | ||||||||
560 | case IRPosition::IRP_FLOAT: | ||||||||
561 | case IRPosition::IRP_FUNCTION: | ||||||||
562 | return; | ||||||||
563 | case IRPosition::IRP_ARGUMENT: | ||||||||
564 | case IRPosition::IRP_RETURNED: | ||||||||
565 | IRPositions.emplace_back(IRPosition::function(*IRP.getAnchorScope())); | ||||||||
566 | return; | ||||||||
567 | case IRPosition::IRP_CALL_SITE: | ||||||||
568 | assert(CB && "Expected call site!")((void)0); | ||||||||
569 | // TODO: We need to look at the operand bundles similar to the redirection | ||||||||
570 | // in CallBase. | ||||||||
571 | if (!CB->hasOperandBundles() || CanIgnoreOperandBundles(*CB)) | ||||||||
572 | if (const Function *Callee = CB->getCalledFunction()) | ||||||||
573 | IRPositions.emplace_back(IRPosition::function(*Callee)); | ||||||||
574 | return; | ||||||||
575 | case IRPosition::IRP_CALL_SITE_RETURNED: | ||||||||
576 | assert(CB && "Expected call site!")((void)0); | ||||||||
577 | // TODO: We need to look at the operand bundles similar to the redirection | ||||||||
578 | // in CallBase. | ||||||||
579 | if (!CB->hasOperandBundles() || CanIgnoreOperandBundles(*CB)) { | ||||||||
580 | if (const Function *Callee = CB->getCalledFunction()) { | ||||||||
581 | IRPositions.emplace_back(IRPosition::returned(*Callee)); | ||||||||
582 | IRPositions.emplace_back(IRPosition::function(*Callee)); | ||||||||
583 | for (const Argument &Arg : Callee->args()) | ||||||||
584 | if (Arg.hasReturnedAttr()) { | ||||||||
585 | IRPositions.emplace_back( | ||||||||
586 | IRPosition::callsite_argument(*CB, Arg.getArgNo())); | ||||||||
587 | IRPositions.emplace_back( | ||||||||
588 | IRPosition::value(*CB->getArgOperand(Arg.getArgNo()))); | ||||||||
589 | IRPositions.emplace_back(IRPosition::argument(Arg)); | ||||||||
590 | } | ||||||||
591 | } | ||||||||
592 | } | ||||||||
593 | IRPositions.emplace_back(IRPosition::callsite_function(*CB)); | ||||||||
594 | return; | ||||||||
595 | case IRPosition::IRP_CALL_SITE_ARGUMENT: { | ||||||||
596 | assert(CB && "Expected call site!")((void)0); | ||||||||
597 | // TODO: We need to look at the operand bundles similar to the redirection | ||||||||
598 | // in CallBase. | ||||||||
599 | if (!CB->hasOperandBundles() || CanIgnoreOperandBundles(*CB)) { | ||||||||
600 | const Function *Callee = CB->getCalledFunction(); | ||||||||
601 | if (Callee) { | ||||||||
602 | if (Argument *Arg = IRP.getAssociatedArgument()) | ||||||||
603 | IRPositions.emplace_back(IRPosition::argument(*Arg)); | ||||||||
604 | IRPositions.emplace_back(IRPosition::function(*Callee)); | ||||||||
605 | } | ||||||||
606 | } | ||||||||
607 | IRPositions.emplace_back(IRPosition::value(IRP.getAssociatedValue())); | ||||||||
608 | return; | ||||||||
609 | } | ||||||||
610 | } | ||||||||
611 | } | ||||||||
612 | |||||||||
613 | bool IRPosition::hasAttr(ArrayRef<Attribute::AttrKind> AKs, | ||||||||
614 | bool IgnoreSubsumingPositions, Attributor *A) const { | ||||||||
615 | SmallVector<Attribute, 4> Attrs; | ||||||||
616 | for (const IRPosition &EquivIRP : SubsumingPositionIterator(*this)) { | ||||||||
617 | for (Attribute::AttrKind AK : AKs) | ||||||||
618 | if (EquivIRP.getAttrsFromIRAttr(AK, Attrs)) | ||||||||
619 | return true; | ||||||||
620 | // The first position returned by the SubsumingPositionIterator is | ||||||||
621 | // always the position itself. If we ignore subsuming positions we | ||||||||
622 | // are done after the first iteration. | ||||||||
623 | if (IgnoreSubsumingPositions) | ||||||||
624 | break; | ||||||||
625 | } | ||||||||
626 | if (A) | ||||||||
627 | for (Attribute::AttrKind AK : AKs) | ||||||||
628 | if (getAttrsFromAssumes(AK, Attrs, *A)) | ||||||||
629 | return true; | ||||||||
630 | return false; | ||||||||
631 | } | ||||||||
632 | |||||||||
633 | void IRPosition::getAttrs(ArrayRef<Attribute::AttrKind> AKs, | ||||||||
634 | SmallVectorImpl<Attribute> &Attrs, | ||||||||
635 | bool IgnoreSubsumingPositions, Attributor *A) const { | ||||||||
636 | for (const IRPosition &EquivIRP : SubsumingPositionIterator(*this)) { | ||||||||
637 | for (Attribute::AttrKind AK : AKs) | ||||||||
638 | EquivIRP.getAttrsFromIRAttr(AK, Attrs); | ||||||||
639 | // The first position returned by the SubsumingPositionIterator is | ||||||||
640 | // always the position itself. If we ignore subsuming positions we | ||||||||
641 | // are done after the first iteration. | ||||||||
642 | if (IgnoreSubsumingPositions) | ||||||||
643 | break; | ||||||||
644 | } | ||||||||
645 | if (A) | ||||||||
646 | for (Attribute::AttrKind AK : AKs) | ||||||||
647 | getAttrsFromAssumes(AK, Attrs, *A); | ||||||||
648 | } | ||||||||
649 | |||||||||
650 | bool IRPosition::getAttrsFromIRAttr(Attribute::AttrKind AK, | ||||||||
651 | SmallVectorImpl<Attribute> &Attrs) const { | ||||||||
652 | if (getPositionKind() == IRP_INVALID || getPositionKind() == IRP_FLOAT) | ||||||||
653 | return false; | ||||||||
654 | |||||||||
655 | AttributeList AttrList; | ||||||||
656 | if (const auto *CB = dyn_cast<CallBase>(&getAnchorValue())) | ||||||||
657 | AttrList = CB->getAttributes(); | ||||||||
658 | else | ||||||||
659 | AttrList = getAssociatedFunction()->getAttributes(); | ||||||||
660 | |||||||||
661 | bool HasAttr = AttrList.hasAttribute(getAttrIdx(), AK); | ||||||||
662 | if (HasAttr) | ||||||||
663 | Attrs.push_back(AttrList.getAttribute(getAttrIdx(), AK)); | ||||||||
664 | return HasAttr; | ||||||||
665 | } | ||||||||
666 | |||||||||
667 | bool IRPosition::getAttrsFromAssumes(Attribute::AttrKind AK, | ||||||||
668 | SmallVectorImpl<Attribute> &Attrs, | ||||||||
669 | Attributor &A) const { | ||||||||
670 | assert(getPositionKind() != IRP_INVALID && "Did expect a valid position!")((void)0); | ||||||||
671 | Value &AssociatedValue = getAssociatedValue(); | ||||||||
672 | |||||||||
673 | const Assume2KnowledgeMap &A2K = | ||||||||
674 | A.getInfoCache().getKnowledgeMap().lookup({&AssociatedValue, AK}); | ||||||||
675 | |||||||||
676 | // Check if we found any potential assume use, if not we don't need to create | ||||||||
677 | // explorer iterators. | ||||||||
678 | if (A2K.empty()) | ||||||||
679 | return false; | ||||||||
680 | |||||||||
681 | LLVMContext &Ctx = AssociatedValue.getContext(); | ||||||||
682 | unsigned AttrsSize = Attrs.size(); | ||||||||
683 | MustBeExecutedContextExplorer &Explorer = | ||||||||
684 | A.getInfoCache().getMustBeExecutedContextExplorer(); | ||||||||
685 | auto EIt = Explorer.begin(getCtxI()), EEnd = Explorer.end(getCtxI()); | ||||||||
686 | for (auto &It : A2K) | ||||||||
687 | if (Explorer.findInContextOf(It.first, EIt, EEnd)) | ||||||||
688 | Attrs.push_back(Attribute::get(Ctx, AK, It.second.Max)); | ||||||||
689 | return AttrsSize != Attrs.size(); | ||||||||
690 | } | ||||||||
691 | |||||||||
692 | void IRPosition::verify() { | ||||||||
693 | #ifdef EXPENSIVE_CHECKS | ||||||||
694 | switch (getPositionKind()) { | ||||||||
695 | case IRP_INVALID: | ||||||||
696 | assert((CBContext == nullptr) &&((void)0) | ||||||||
697 | "Invalid position must not have CallBaseContext!")((void)0); | ||||||||
698 | assert(!Enc.getOpaqueValue() &&((void)0) | ||||||||
699 | "Expected a nullptr for an invalid position!")((void)0); | ||||||||
700 | return; | ||||||||
701 | case IRP_FLOAT: | ||||||||
702 | assert((!isa<CallBase>(&getAssociatedValue()) &&((void)0) | ||||||||
703 | !isa<Argument>(&getAssociatedValue())) &&((void)0) | ||||||||
704 | "Expected specialized kind for call base and argument values!")((void)0); | ||||||||
705 | return; | ||||||||
706 | case IRP_RETURNED: | ||||||||
707 | assert(isa<Function>(getAsValuePtr()) &&((void)0) | ||||||||
708 | "Expected function for a 'returned' position!")((void)0); | ||||||||
709 | assert(getAsValuePtr() == &getAssociatedValue() &&((void)0) | ||||||||
710 | "Associated value mismatch!")((void)0); | ||||||||
711 | return; | ||||||||
712 | case IRP_CALL_SITE_RETURNED: | ||||||||
713 | assert((CBContext == nullptr) &&((void)0) | ||||||||
714 | "'call site returned' position must not have CallBaseContext!")((void)0); | ||||||||
715 | assert((isa<CallBase>(getAsValuePtr())) &&((void)0) | ||||||||
716 | "Expected call base for 'call site returned' position!")((void)0); | ||||||||
717 | assert(getAsValuePtr() == &getAssociatedValue() &&((void)0) | ||||||||
718 | "Associated value mismatch!")((void)0); | ||||||||
719 | return; | ||||||||
720 | case IRP_CALL_SITE: | ||||||||
721 | assert((CBContext == nullptr) &&((void)0) | ||||||||
722 | "'call site function' position must not have CallBaseContext!")((void)0); | ||||||||
723 | assert((isa<CallBase>(getAsValuePtr())) &&((void)0) | ||||||||
724 | "Expected call base for 'call site function' position!")((void)0); | ||||||||
725 | assert(getAsValuePtr() == &getAssociatedValue() &&((void)0) | ||||||||
726 | "Associated value mismatch!")((void)0); | ||||||||
727 | return; | ||||||||
728 | case IRP_FUNCTION: | ||||||||
729 | assert(isa<Function>(getAsValuePtr()) &&((void)0) | ||||||||
730 | "Expected function for a 'function' position!")((void)0); | ||||||||
731 | assert(getAsValuePtr() == &getAssociatedValue() &&((void)0) | ||||||||
732 | "Associated value mismatch!")((void)0); | ||||||||
733 | return; | ||||||||
734 | case IRP_ARGUMENT: | ||||||||
735 | assert(isa<Argument>(getAsValuePtr()) &&((void)0) | ||||||||
736 | "Expected argument for a 'argument' position!")((void)0); | ||||||||
737 | assert(getAsValuePtr() == &getAssociatedValue() &&((void)0) | ||||||||
738 | "Associated value mismatch!")((void)0); | ||||||||
739 | return; | ||||||||
740 | case IRP_CALL_SITE_ARGUMENT: { | ||||||||
741 | assert((CBContext == nullptr) &&((void)0) | ||||||||
742 | "'call site argument' position must not have CallBaseContext!")((void)0); | ||||||||
743 | Use *U = getAsUsePtr(); | ||||||||
744 | assert(U && "Expected use for a 'call site argument' position!")((void)0); | ||||||||
745 | assert(isa<CallBase>(U->getUser()) &&((void)0) | ||||||||
746 | "Expected call base user for a 'call site argument' position!")((void)0); | ||||||||
747 | assert(cast<CallBase>(U->getUser())->isArgOperand(U) &&((void)0) | ||||||||
748 | "Expected call base argument operand for a 'call site argument' "((void)0) | ||||||||
749 | "position")((void)0); | ||||||||
750 | assert(cast<CallBase>(U->getUser())->getArgOperandNo(U) ==((void)0) | ||||||||
751 | unsigned(getCallSiteArgNo()) &&((void)0) | ||||||||
752 | "Argument number mismatch!")((void)0); | ||||||||
753 | assert(U->get() == &getAssociatedValue() && "Associated value mismatch!")((void)0); | ||||||||
754 | return; | ||||||||
755 | } | ||||||||
756 | } | ||||||||
757 | #endif | ||||||||
758 | } | ||||||||
759 | |||||||||
760 | Optional<Constant *> | ||||||||
761 | Attributor::getAssumedConstant(const IRPosition &IRP, | ||||||||
762 | const AbstractAttribute &AA, | ||||||||
763 | bool &UsedAssumedInformation) { | ||||||||
764 | // First check all callbacks provided by outside AAs. If any of them returns | ||||||||
765 | // a non-null value that is different from the associated value, or None, we | ||||||||
766 | // assume it's simpliied. | ||||||||
767 | for (auto &CB : SimplificationCallbacks.lookup(IRP)) { | ||||||||
768 | Optional<Value *> SimplifiedV = CB(IRP, &AA, UsedAssumedInformation); | ||||||||
769 | if (!SimplifiedV.hasValue()) | ||||||||
770 | return llvm::None; | ||||||||
771 | if (isa_and_nonnull<Constant>(*SimplifiedV)) | ||||||||
772 | return cast<Constant>(*SimplifiedV); | ||||||||
773 | return nullptr; | ||||||||
774 | } | ||||||||
775 | const auto &ValueSimplifyAA = | ||||||||
776 | getAAFor<AAValueSimplify>(AA, IRP, DepClassTy::NONE); | ||||||||
777 | Optional<Value *> SimplifiedV = | ||||||||
778 | ValueSimplifyAA.getAssumedSimplifiedValue(*this); | ||||||||
779 | bool IsKnown = ValueSimplifyAA.isAtFixpoint(); | ||||||||
780 | UsedAssumedInformation |= !IsKnown; | ||||||||
781 | if (!SimplifiedV.hasValue()) { | ||||||||
782 | recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL); | ||||||||
783 | return llvm::None; | ||||||||
784 | } | ||||||||
785 | if (isa_and_nonnull<UndefValue>(SimplifiedV.getValue())) { | ||||||||
786 | recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL); | ||||||||
787 | return UndefValue::get(IRP.getAssociatedType()); | ||||||||
788 | } | ||||||||
789 | Constant *CI = dyn_cast_or_null<Constant>(SimplifiedV.getValue()); | ||||||||
790 | if (CI) | ||||||||
791 | CI = dyn_cast_or_null<Constant>( | ||||||||
792 | AA::getWithType(*CI, *IRP.getAssociatedType())); | ||||||||
793 | if (CI) | ||||||||
794 | recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL); | ||||||||
795 | return CI; | ||||||||
796 | } | ||||||||
797 | |||||||||
798 | Optional<Value *> | ||||||||
799 | Attributor::getAssumedSimplified(const IRPosition &IRP, | ||||||||
800 | const AbstractAttribute *AA, | ||||||||
801 | bool &UsedAssumedInformation) { | ||||||||
802 | // First check all callbacks provided by outside AAs. If any of them returns | ||||||||
803 | // a non-null value that is different from the associated value, or None, we | ||||||||
804 | // assume it's simpliied. | ||||||||
805 | for (auto &CB : SimplificationCallbacks.lookup(IRP)) | ||||||||
806 | return CB(IRP, AA, UsedAssumedInformation); | ||||||||
807 | |||||||||
808 | // If no high-level/outside simplification occured, use AAValueSimplify. | ||||||||
809 | const auto &ValueSimplifyAA = | ||||||||
810 | getOrCreateAAFor<AAValueSimplify>(IRP, AA, DepClassTy::NONE); | ||||||||
811 | Optional<Value *> SimplifiedV = | ||||||||
812 | ValueSimplifyAA.getAssumedSimplifiedValue(*this); | ||||||||
813 | bool IsKnown = ValueSimplifyAA.isAtFixpoint(); | ||||||||
814 | UsedAssumedInformation |= !IsKnown; | ||||||||
815 | if (!SimplifiedV.hasValue()) { | ||||||||
816 | if (AA) | ||||||||
817 | recordDependence(ValueSimplifyAA, *AA, DepClassTy::OPTIONAL); | ||||||||
818 | return llvm::None; | ||||||||
819 | } | ||||||||
820 | if (*SimplifiedV == nullptr) | ||||||||
821 | return const_cast<Value *>(&IRP.getAssociatedValue()); | ||||||||
822 | if (Value *SimpleV = | ||||||||
823 | AA::getWithType(**SimplifiedV, *IRP.getAssociatedType())) { | ||||||||
824 | if (AA) | ||||||||
825 | recordDependence(ValueSimplifyAA, *AA, DepClassTy::OPTIONAL); | ||||||||
826 | return SimpleV; | ||||||||
827 | } | ||||||||
828 | return const_cast<Value *>(&IRP.getAssociatedValue()); | ||||||||
829 | } | ||||||||
830 | |||||||||
831 | Optional<Value *> Attributor::translateArgumentToCallSiteContent( | ||||||||
832 | Optional<Value *> V, CallBase &CB, const AbstractAttribute &AA, | ||||||||
833 | bool &UsedAssumedInformation) { | ||||||||
834 | if (!V.hasValue()) | ||||||||
835 | return V; | ||||||||
836 | if (*V == nullptr || isa<Constant>(*V)) | ||||||||
837 | return V; | ||||||||
838 | if (auto *Arg = dyn_cast<Argument>(*V)) | ||||||||
839 | if (CB.getCalledFunction() == Arg->getParent()) | ||||||||
840 | if (!Arg->hasPointeeInMemoryValueAttr()) | ||||||||
841 | return getAssumedSimplified( | ||||||||
842 | IRPosition::callsite_argument(CB, Arg->getArgNo()), AA, | ||||||||
843 | UsedAssumedInformation); | ||||||||
844 | return nullptr; | ||||||||
845 | } | ||||||||
846 | |||||||||
847 | Attributor::~Attributor() { | ||||||||
848 | // The abstract attributes are allocated via the BumpPtrAllocator Allocator, | ||||||||
849 | // thus we cannot delete them. We can, and want to, destruct them though. | ||||||||
850 | for (auto &DepAA : DG.SyntheticRoot.Deps) { | ||||||||
851 | AbstractAttribute *AA = cast<AbstractAttribute>(DepAA.getPointer()); | ||||||||
852 | AA->~AbstractAttribute(); | ||||||||
853 | } | ||||||||
854 | } | ||||||||
855 | |||||||||
856 | bool Attributor::isAssumedDead(const AbstractAttribute &AA, | ||||||||
857 | const AAIsDead *FnLivenessAA, | ||||||||
858 | bool &UsedAssumedInformation, | ||||||||
859 | bool CheckBBLivenessOnly, DepClassTy DepClass) { | ||||||||
860 | const IRPosition &IRP = AA.getIRPosition(); | ||||||||
861 | if (!Functions.count(IRP.getAnchorScope())) | ||||||||
862 | return false; | ||||||||
863 | return isAssumedDead(IRP, &AA, FnLivenessAA, UsedAssumedInformation, | ||||||||
864 | CheckBBLivenessOnly, DepClass); | ||||||||
865 | } | ||||||||
866 | |||||||||
867 | bool Attributor::isAssumedDead(const Use &U, | ||||||||
868 | const AbstractAttribute *QueryingAA, | ||||||||
869 | const AAIsDead *FnLivenessAA, | ||||||||
870 | bool &UsedAssumedInformation, | ||||||||
871 | bool CheckBBLivenessOnly, DepClassTy DepClass) { | ||||||||
872 | Instruction *UserI = dyn_cast<Instruction>(U.getUser()); | ||||||||
873 | if (!UserI) | ||||||||
874 | return isAssumedDead(IRPosition::value(*U.get()), QueryingAA, FnLivenessAA, | ||||||||
875 | UsedAssumedInformation, CheckBBLivenessOnly, DepClass); | ||||||||
876 | |||||||||
877 | if (auto *CB = dyn_cast<CallBase>(UserI)) { | ||||||||
878 | // For call site argument uses we can check if the argument is | ||||||||
879 | // unused/dead. | ||||||||
880 | if (CB->isArgOperand(&U)) { | ||||||||
881 | const IRPosition &CSArgPos = | ||||||||
882 | IRPosition::callsite_argument(*CB, CB->getArgOperandNo(&U)); | ||||||||
883 | return isAssumedDead(CSArgPos, QueryingAA, FnLivenessAA, | ||||||||
884 | UsedAssumedInformation, CheckBBLivenessOnly, | ||||||||
885 | DepClass); | ||||||||
886 | } | ||||||||
887 | } else if (ReturnInst *RI = dyn_cast<ReturnInst>(UserI)) { | ||||||||
888 | const IRPosition &RetPos = IRPosition::returned(*RI->getFunction()); | ||||||||
889 | return isAssumedDead(RetPos, QueryingAA, FnLivenessAA, | ||||||||
890 | UsedAssumedInformation, CheckBBLivenessOnly, DepClass); | ||||||||
891 | } else if (PHINode *PHI = dyn_cast<PHINode>(UserI)) { | ||||||||
892 | BasicBlock *IncomingBB = PHI->getIncomingBlock(U); | ||||||||
893 | return isAssumedDead(*IncomingBB->getTerminator(), QueryingAA, FnLivenessAA, | ||||||||
894 | UsedAssumedInformation, CheckBBLivenessOnly, DepClass); | ||||||||
895 | } | ||||||||
896 | |||||||||
897 | return isAssumedDead(IRPosition::value(*UserI), QueryingAA, FnLivenessAA, | ||||||||
898 | UsedAssumedInformation, CheckBBLivenessOnly, DepClass); | ||||||||
899 | } | ||||||||
900 | |||||||||
901 | bool Attributor::isAssumedDead(const Instruction &I, | ||||||||
902 | const AbstractAttribute *QueryingAA, | ||||||||
903 | const AAIsDead *FnLivenessAA, | ||||||||
904 | bool &UsedAssumedInformation, | ||||||||
905 | bool CheckBBLivenessOnly, DepClassTy DepClass) { | ||||||||
906 | const IRPosition::CallBaseContext *CBCtx = | ||||||||
907 | QueryingAA ? QueryingAA->getCallBaseContext() : nullptr; | ||||||||
908 | |||||||||
909 | if (ManifestAddedBlocks.contains(I.getParent())) | ||||||||
910 | return false; | ||||||||
911 | |||||||||
912 | if (!FnLivenessAA) | ||||||||
913 | FnLivenessAA = | ||||||||
914 | lookupAAFor<AAIsDead>(IRPosition::function(*I.getFunction(), CBCtx), | ||||||||
915 | QueryingAA, DepClassTy::NONE); | ||||||||
916 | |||||||||
917 | // If we have a context instruction and a liveness AA we use it. | ||||||||
918 | if (FnLivenessAA && | ||||||||
919 | FnLivenessAA->getIRPosition().getAnchorScope() == I.getFunction() && | ||||||||
920 | FnLivenessAA->isAssumedDead(&I)) { | ||||||||
921 | if (QueryingAA) | ||||||||
922 | recordDependence(*FnLivenessAA, *QueryingAA, DepClass); | ||||||||
923 | if (!FnLivenessAA->isKnownDead(&I)) | ||||||||
924 | UsedAssumedInformation = true; | ||||||||
925 | return true; | ||||||||
926 | } | ||||||||
927 | |||||||||
928 | if (CheckBBLivenessOnly) | ||||||||
929 | return false; | ||||||||
930 | |||||||||
931 | const AAIsDead &IsDeadAA = getOrCreateAAFor<AAIsDead>( | ||||||||
932 | IRPosition::value(I, CBCtx), QueryingAA, DepClassTy::NONE); | ||||||||
933 | // Don't check liveness for AAIsDead. | ||||||||
934 | if (QueryingAA == &IsDeadAA) | ||||||||
935 | return false; | ||||||||
936 | |||||||||
937 | if (IsDeadAA.isAssumedDead()) { | ||||||||
938 | if (QueryingAA) | ||||||||
939 | recordDependence(IsDeadAA, *QueryingAA, DepClass); | ||||||||
940 | if (!IsDeadAA.isKnownDead()) | ||||||||
941 | UsedAssumedInformation = true; | ||||||||
942 | return true; | ||||||||
943 | } | ||||||||
944 | |||||||||
945 | return false; | ||||||||
946 | } | ||||||||
947 | |||||||||
948 | bool Attributor::isAssumedDead(const IRPosition &IRP, | ||||||||
949 | const AbstractAttribute *QueryingAA, | ||||||||
950 | const AAIsDead *FnLivenessAA, | ||||||||
951 | bool &UsedAssumedInformation, | ||||||||
952 | bool CheckBBLivenessOnly, DepClassTy DepClass) { | ||||||||
953 | Instruction *CtxI = IRP.getCtxI(); | ||||||||
954 | if (CtxI && | ||||||||
955 | isAssumedDead(*CtxI, QueryingAA, FnLivenessAA, UsedAssumedInformation, | ||||||||
956 | /* CheckBBLivenessOnly */ true, | ||||||||
957 | CheckBBLivenessOnly ? DepClass : DepClassTy::OPTIONAL)) | ||||||||
958 | return true; | ||||||||
959 | |||||||||
960 | if (CheckBBLivenessOnly) | ||||||||
961 | return false; | ||||||||
962 | |||||||||
963 | // If we haven't succeeded we query the specific liveness info for the IRP. | ||||||||
964 | const AAIsDead *IsDeadAA; | ||||||||
965 | if (IRP.getPositionKind() == IRPosition::IRP_CALL_SITE) | ||||||||
966 | IsDeadAA = &getOrCreateAAFor<AAIsDead>( | ||||||||
967 | IRPosition::callsite_returned(cast<CallBase>(IRP.getAssociatedValue())), | ||||||||
968 | QueryingAA, DepClassTy::NONE); | ||||||||
969 | else | ||||||||
970 | IsDeadAA = &getOrCreateAAFor<AAIsDead>(IRP, QueryingAA, DepClassTy::NONE); | ||||||||
971 | // Don't check liveness for AAIsDead. | ||||||||
972 | if (QueryingAA == IsDeadAA) | ||||||||
973 | return false; | ||||||||
974 | |||||||||
975 | if (IsDeadAA->isAssumedDead()) { | ||||||||
976 | if (QueryingAA) | ||||||||
977 | recordDependence(*IsDeadAA, *QueryingAA, DepClass); | ||||||||
978 | if (!IsDeadAA->isKnownDead()) | ||||||||
979 | UsedAssumedInformation = true; | ||||||||
980 | return true; | ||||||||
981 | } | ||||||||
982 | |||||||||
983 | return false; | ||||||||
984 | } | ||||||||
985 | |||||||||
986 | bool Attributor::isAssumedDead(const BasicBlock &BB, | ||||||||
987 | const AbstractAttribute *QueryingAA, | ||||||||
988 | const AAIsDead *FnLivenessAA, | ||||||||
989 | DepClassTy DepClass) { | ||||||||
990 | if (!FnLivenessAA) | ||||||||
991 | FnLivenessAA = lookupAAFor<AAIsDead>(IRPosition::function(*BB.getParent()), | ||||||||
992 | QueryingAA, DepClassTy::NONE); | ||||||||
993 | if (FnLivenessAA->isAssumedDead(&BB)) { | ||||||||
994 | if (QueryingAA) | ||||||||
995 | recordDependence(*FnLivenessAA, *QueryingAA, DepClass); | ||||||||
996 | return true; | ||||||||
997 | } | ||||||||
998 | |||||||||
999 | return false; | ||||||||
1000 | } | ||||||||
1001 | |||||||||
1002 | bool Attributor::checkForAllUses(function_ref<bool(const Use &, bool &)> Pred, | ||||||||
1003 | const AbstractAttribute &QueryingAA, | ||||||||
1004 | const Value &V, bool CheckBBLivenessOnly, | ||||||||
1005 | DepClassTy LivenessDepClass) { | ||||||||
1006 | |||||||||
1007 | // Check the trivial case first as it catches void values. | ||||||||
1008 | if (V.use_empty()) | ||||||||
1009 | return true; | ||||||||
1010 | |||||||||
1011 | const IRPosition &IRP = QueryingAA.getIRPosition(); | ||||||||
1012 | SmallVector<const Use *, 16> Worklist; | ||||||||
1013 | SmallPtrSet<const Use *, 16> Visited; | ||||||||
1014 | |||||||||
1015 | for (const Use &U : V.uses()) | ||||||||
1016 | Worklist.push_back(&U); | ||||||||
1017 | |||||||||
1018 | LLVM_DEBUG(dbgs() << "[Attributor] Got " << Worklist.size()do { } while (false) | ||||||||
1019 | << " initial uses to check\n")do { } while (false); | ||||||||
1020 | |||||||||
1021 | const Function *ScopeFn = IRP.getAnchorScope(); | ||||||||
1022 | const auto *LivenessAA = | ||||||||
1023 | ScopeFn ? &getAAFor<AAIsDead>(QueryingAA, IRPosition::function(*ScopeFn), | ||||||||
1024 | DepClassTy::NONE) | ||||||||
1025 | : nullptr; | ||||||||
1026 | |||||||||
1027 | while (!Worklist.empty()) { | ||||||||
1028 | const Use *U = Worklist.pop_back_val(); | ||||||||
1029 | if (isa<PHINode>(U->getUser()) && !Visited.insert(U).second) | ||||||||
1030 | continue; | ||||||||
1031 | LLVM_DEBUG(dbgs() << "[Attributor] Check use: " << **U << " in "do { } while (false) | ||||||||
1032 | << *U->getUser() << "\n")do { } while (false); | ||||||||
1033 | bool UsedAssumedInformation = false; | ||||||||
1034 | if (isAssumedDead(*U, &QueryingAA, LivenessAA, UsedAssumedInformation, | ||||||||
1035 | CheckBBLivenessOnly, LivenessDepClass)) { | ||||||||
1036 | LLVM_DEBUG(dbgs() << "[Attributor] Dead use, skip!\n")do { } while (false); | ||||||||
1037 | continue; | ||||||||
1038 | } | ||||||||
1039 | if (U->getUser()->isDroppable()) { | ||||||||
1040 | LLVM_DEBUG(dbgs() << "[Attributor] Droppable user, skip!\n")do { } while (false); | ||||||||
1041 | continue; | ||||||||
1042 | } | ||||||||
1043 | |||||||||
1044 | if (auto *SI = dyn_cast<StoreInst>(U->getUser())) { | ||||||||
1045 | if (&SI->getOperandUse(0) == U) { | ||||||||
1046 | SmallSetVector<Value *, 4> PotentialCopies; | ||||||||
1047 | if (AA::getPotentialCopiesOfStoredValue(*this, *SI, PotentialCopies, | ||||||||
1048 | QueryingAA, | ||||||||
1049 | UsedAssumedInformation)) { | ||||||||
1050 | LLVM_DEBUG(dbgs() << "[Attributor] Value is stored, continue with "do { } while (false) | ||||||||
1051 | << PotentialCopies.size()do { } while (false) | ||||||||
1052 | << " potential copies instead!\n")do { } while (false); | ||||||||
1053 | for (Value *PotentialCopy : PotentialCopies) | ||||||||
1054 | for (const Use &U : PotentialCopy->uses()) | ||||||||
1055 | Worklist.push_back(&U); | ||||||||
1056 | continue; | ||||||||
1057 | } | ||||||||
1058 | } | ||||||||
1059 | } | ||||||||
1060 | |||||||||
1061 | bool Follow = false; | ||||||||
1062 | if (!Pred(*U, Follow)) | ||||||||
1063 | return false; | ||||||||
1064 | if (!Follow) | ||||||||
1065 | continue; | ||||||||
1066 | for (const Use &UU : U->getUser()->uses()) | ||||||||
1067 | Worklist.push_back(&UU); | ||||||||
1068 | } | ||||||||
1069 | |||||||||
1070 | return true; | ||||||||
1071 | } | ||||||||
1072 | |||||||||
1073 | bool Attributor::checkForAllCallSites(function_ref<bool(AbstractCallSite)> Pred, | ||||||||
1074 | const AbstractAttribute &QueryingAA, | ||||||||
1075 | bool RequireAllCallSites, | ||||||||
1076 | bool &AllCallSitesKnown) { | ||||||||
1077 | // We can try to determine information from | ||||||||
1078 | // the call sites. However, this is only possible all call sites are known, | ||||||||
1079 | // hence the function has internal linkage. | ||||||||
1080 | const IRPosition &IRP = QueryingAA.getIRPosition(); | ||||||||
1081 | const Function *AssociatedFunction = IRP.getAssociatedFunction(); | ||||||||
1082 | if (!AssociatedFunction) { | ||||||||
1083 | LLVM_DEBUG(dbgs() << "[Attributor] No function associated with " << IRPdo { } while (false) | ||||||||
1084 | << "\n")do { } while (false); | ||||||||
1085 | AllCallSitesKnown = false; | ||||||||
1086 | return false; | ||||||||
1087 | } | ||||||||
1088 | |||||||||
1089 | return checkForAllCallSites(Pred, *AssociatedFunction, RequireAllCallSites, | ||||||||
1090 | &QueryingAA, AllCallSitesKnown); | ||||||||
1091 | } | ||||||||
1092 | |||||||||
1093 | bool Attributor::checkForAllCallSites(function_ref<bool(AbstractCallSite)> Pred, | ||||||||
1094 | const Function &Fn, | ||||||||
1095 | bool RequireAllCallSites, | ||||||||
1096 | const AbstractAttribute *QueryingAA, | ||||||||
1097 | bool &AllCallSitesKnown) { | ||||||||
1098 | if (RequireAllCallSites && !Fn.hasLocalLinkage()) { | ||||||||
1099 | LLVM_DEBUG(do { } while (false) | ||||||||
1100 | dbgs()do { } while (false) | ||||||||
1101 | << "[Attributor] Function " << Fn.getName()do { } while (false) | ||||||||
1102 | << " has no internal linkage, hence not all call sites are known\n")do { } while (false); | ||||||||
1103 | AllCallSitesKnown = false; | ||||||||
1104 | return false; | ||||||||
1105 | } | ||||||||
1106 | |||||||||
1107 | // If we do not require all call sites we might not see all. | ||||||||
1108 | AllCallSitesKnown = RequireAllCallSites; | ||||||||
1109 | |||||||||
1110 | SmallVector<const Use *, 8> Uses(make_pointer_range(Fn.uses())); | ||||||||
1111 | for (unsigned u = 0; u < Uses.size(); ++u) { | ||||||||
1112 | const Use &U = *Uses[u]; | ||||||||
1113 | LLVM_DEBUG(dbgs() << "[Attributor] Check use: " << *U << " in "do { } while (false) | ||||||||
1114 | << *U.getUser() << "\n")do { } while (false); | ||||||||
1115 | bool UsedAssumedInformation = false; | ||||||||
1116 | if (isAssumedDead(U, QueryingAA, nullptr, UsedAssumedInformation, | ||||||||
1117 | /* CheckBBLivenessOnly */ true)) { | ||||||||
1118 | LLVM_DEBUG(dbgs() << "[Attributor] Dead use, skip!\n")do { } while (false); | ||||||||
1119 | continue; | ||||||||
1120 | } | ||||||||
1121 | if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U.getUser())) { | ||||||||
1122 | if (CE->isCast() && CE->getType()->isPointerTy() && | ||||||||
1123 | CE->getType()->getPointerElementType()->isFunctionTy()) { | ||||||||
1124 | for (const Use &CEU : CE->uses()) | ||||||||
1125 | Uses.push_back(&CEU); | ||||||||
1126 | continue; | ||||||||
1127 | } | ||||||||
1128 | } | ||||||||
1129 | |||||||||
1130 | AbstractCallSite ACS(&U); | ||||||||
1131 | if (!ACS) { | ||||||||
1132 | LLVM_DEBUG(dbgs() << "[Attributor] Function " << Fn.getName()do { } while (false) | ||||||||
1133 | << " has non call site use " << *U.get() << " in "do { } while (false) | ||||||||
1134 | << *U.getUser() << "\n")do { } while (false); | ||||||||
1135 | // BlockAddress users are allowed. | ||||||||
1136 | if (isa<BlockAddress>(U.getUser())) | ||||||||
1137 | continue; | ||||||||
1138 | return false; | ||||||||
1139 | } | ||||||||
1140 | |||||||||
1141 | const Use *EffectiveUse = | ||||||||
1142 | ACS.isCallbackCall() ? &ACS.getCalleeUseForCallback() : &U; | ||||||||
1143 | if (!ACS.isCallee(EffectiveUse)) { | ||||||||
1144 | if (!RequireAllCallSites) | ||||||||
1145 | continue; | ||||||||
1146 | LLVM_DEBUG(dbgs() << "[Attributor] User " << EffectiveUse->getUser()do { } while (false) | ||||||||
1147 | << " is an invalid use of " << Fn.getName() << "\n")do { } while (false); | ||||||||
1148 | return false; | ||||||||
1149 | } | ||||||||
1150 | |||||||||
1151 | // Make sure the arguments that can be matched between the call site and the | ||||||||
1152 | // callee argee on their type. It is unlikely they do not and it doesn't | ||||||||
1153 | // make sense for all attributes to know/care about this. | ||||||||
1154 | assert(&Fn == ACS.getCalledFunction() && "Expected known callee")((void)0); | ||||||||
1155 | unsigned MinArgsParams = | ||||||||
1156 | std::min(size_t(ACS.getNumArgOperands()), Fn.arg_size()); | ||||||||
1157 | for (unsigned u = 0; u < MinArgsParams; ++u) { | ||||||||
1158 | Value *CSArgOp = ACS.getCallArgOperand(u); | ||||||||
1159 | if (CSArgOp && Fn.getArg(u)->getType() != CSArgOp->getType()) { | ||||||||
1160 | LLVM_DEBUG(do { } while (false) | ||||||||
1161 | dbgs() << "[Attributor] Call site / callee argument type mismatch ["do { } while (false) | ||||||||
1162 | << u << "@" << Fn.getName() << ": "do { } while (false) | ||||||||
1163 | << *Fn.getArg(u)->getType() << " vs. "do { } while (false) | ||||||||
1164 | << *ACS.getCallArgOperand(u)->getType() << "\n")do { } while (false); | ||||||||
1165 | return false; | ||||||||
1166 | } | ||||||||
1167 | } | ||||||||
1168 | |||||||||
1169 | if (Pred(ACS)) | ||||||||
1170 | continue; | ||||||||
1171 | |||||||||
1172 | LLVM_DEBUG(dbgs() << "[Attributor] Call site callback failed for "do { } while (false) | ||||||||
1173 | << *ACS.getInstruction() << "\n")do { } while (false); | ||||||||
1174 | return false; | ||||||||
1175 | } | ||||||||
1176 | |||||||||
1177 | return true; | ||||||||
1178 | } | ||||||||
1179 | |||||||||
1180 | bool Attributor::shouldPropagateCallBaseContext(const IRPosition &IRP) { | ||||||||
1181 | // TODO: Maintain a cache of Values that are | ||||||||
1182 | // on the pathway from a Argument to a Instruction that would effect the | ||||||||
1183 | // liveness/return state etc. | ||||||||
1184 | return EnableCallSiteSpecific; | ||||||||
1185 | } | ||||||||
1186 | |||||||||
1187 | bool Attributor::checkForAllReturnedValuesAndReturnInsts( | ||||||||
1188 | function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred, | ||||||||
1189 | const AbstractAttribute &QueryingAA) { | ||||||||
1190 | |||||||||
1191 | const IRPosition &IRP = QueryingAA.getIRPosition(); | ||||||||
1192 | // Since we need to provide return instructions we have to have an exact | ||||||||
1193 | // definition. | ||||||||
1194 | const Function *AssociatedFunction = IRP.getAssociatedFunction(); | ||||||||
1195 | if (!AssociatedFunction) | ||||||||
1196 | return false; | ||||||||
1197 | |||||||||
1198 | // If this is a call site query we use the call site specific return values | ||||||||
1199 | // and liveness information. | ||||||||
1200 | // TODO: use the function scope once we have call site AAReturnedValues. | ||||||||
1201 | const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction); | ||||||||
1202 | const auto &AARetVal = | ||||||||
1203 | getAAFor<AAReturnedValues>(QueryingAA, QueryIRP, DepClassTy::REQUIRED); | ||||||||
1204 | if (!AARetVal.getState().isValidState()) | ||||||||
1205 | return false; | ||||||||
1206 | |||||||||
1207 | return AARetVal.checkForAllReturnedValuesAndReturnInsts(Pred); | ||||||||
1208 | } | ||||||||
1209 | |||||||||
1210 | bool Attributor::checkForAllReturnedValues( | ||||||||
1211 | function_ref<bool(Value &)> Pred, const AbstractAttribute &QueryingAA) { | ||||||||
1212 | |||||||||
1213 | const IRPosition &IRP = QueryingAA.getIRPosition(); | ||||||||
1214 | const Function *AssociatedFunction = IRP.getAssociatedFunction(); | ||||||||
1215 | if (!AssociatedFunction) | ||||||||
1216 | return false; | ||||||||
1217 | |||||||||
1218 | // TODO: use the function scope once we have call site AAReturnedValues. | ||||||||
1219 | const IRPosition &QueryIRP = IRPosition::function( | ||||||||
1220 | *AssociatedFunction, QueryingAA.getCallBaseContext()); | ||||||||
1221 | const auto &AARetVal = | ||||||||
1222 | getAAFor<AAReturnedValues>(QueryingAA, QueryIRP, DepClassTy::REQUIRED); | ||||||||
1223 | if (!AARetVal.getState().isValidState()) | ||||||||
1224 | return false; | ||||||||
1225 | |||||||||
1226 | return AARetVal.checkForAllReturnedValuesAndReturnInsts( | ||||||||
1227 | [&](Value &RV, const SmallSetVector<ReturnInst *, 4> &) { | ||||||||
1228 | return Pred(RV); | ||||||||
1229 | }); | ||||||||
1230 | } | ||||||||
1231 | |||||||||
1232 | static bool checkForAllInstructionsImpl( | ||||||||
1233 | Attributor *A, InformationCache::OpcodeInstMapTy &OpcodeInstMap, | ||||||||
1234 | function_ref<bool(Instruction &)> Pred, const AbstractAttribute *QueryingAA, | ||||||||
1235 | const AAIsDead *LivenessAA, const ArrayRef<unsigned> &Opcodes, | ||||||||
1236 | bool &UsedAssumedInformation, bool CheckBBLivenessOnly = false, | ||||||||
1237 | bool CheckPotentiallyDead = false) { | ||||||||
1238 | for (unsigned Opcode : Opcodes) { | ||||||||
1239 | // Check if we have instructions with this opcode at all first. | ||||||||
1240 | auto *Insts = OpcodeInstMap.lookup(Opcode); | ||||||||
1241 | if (!Insts) | ||||||||
1242 | continue; | ||||||||
1243 | |||||||||
1244 | for (Instruction *I : *Insts) { | ||||||||
1245 | // Skip dead instructions. | ||||||||
1246 | if (A && !CheckPotentiallyDead && | ||||||||
1247 | A->isAssumedDead(IRPosition::value(*I), QueryingAA, LivenessAA, | ||||||||
1248 | UsedAssumedInformation, CheckBBLivenessOnly)) | ||||||||
1249 | continue; | ||||||||
1250 | |||||||||
1251 | if (!Pred(*I)) | ||||||||
1252 | return false; | ||||||||
1253 | } | ||||||||
1254 | } | ||||||||
1255 | return true; | ||||||||
1256 | } | ||||||||
1257 | |||||||||
1258 | bool Attributor::checkForAllInstructions(function_ref<bool(Instruction &)> Pred, | ||||||||
1259 | const AbstractAttribute &QueryingAA, | ||||||||
1260 | const ArrayRef<unsigned> &Opcodes, | ||||||||
1261 | bool &UsedAssumedInformation, | ||||||||
1262 | bool CheckBBLivenessOnly, | ||||||||
1263 | bool CheckPotentiallyDead) { | ||||||||
1264 | |||||||||
1265 | const IRPosition &IRP = QueryingAA.getIRPosition(); | ||||||||
1266 | // Since we need to provide instructions we have to have an exact definition. | ||||||||
1267 | const Function *AssociatedFunction = IRP.getAssociatedFunction(); | ||||||||
1268 | if (!AssociatedFunction) | ||||||||
1269 | return false; | ||||||||
1270 | |||||||||
1271 | if (AssociatedFunction->isDeclaration()) | ||||||||
1272 | return false; | ||||||||
1273 | |||||||||
1274 | // TODO: use the function scope once we have call site AAReturnedValues. | ||||||||
1275 | const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction); | ||||||||
1276 | const auto *LivenessAA = | ||||||||
1277 | (CheckBBLivenessOnly || CheckPotentiallyDead) | ||||||||
1278 | ? nullptr | ||||||||
1279 | : &(getAAFor<AAIsDead>(QueryingAA, QueryIRP, DepClassTy::NONE)); | ||||||||
1280 | |||||||||
1281 | auto &OpcodeInstMap = | ||||||||
1282 | InfoCache.getOpcodeInstMapForFunction(*AssociatedFunction); | ||||||||
1283 | if (!checkForAllInstructionsImpl(this, OpcodeInstMap, Pred, &QueryingAA, | ||||||||
1284 | LivenessAA, Opcodes, UsedAssumedInformation, | ||||||||
1285 | CheckBBLivenessOnly, CheckPotentiallyDead)) | ||||||||
1286 | return false; | ||||||||
1287 | |||||||||
1288 | return true; | ||||||||
1289 | } | ||||||||
1290 | |||||||||
1291 | bool Attributor::checkForAllReadWriteInstructions( | ||||||||
1292 | function_ref<bool(Instruction &)> Pred, AbstractAttribute &QueryingAA, | ||||||||
1293 | bool &UsedAssumedInformation) { | ||||||||
1294 | |||||||||
1295 | const Function *AssociatedFunction = | ||||||||
1296 | QueryingAA.getIRPosition().getAssociatedFunction(); | ||||||||
1297 | if (!AssociatedFunction
| ||||||||
| |||||||||
1298 | return false; | ||||||||
1299 | |||||||||
1300 | // TODO: use the function scope once we have call site AAReturnedValues. | ||||||||
1301 | const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction); | ||||||||
1302 | const auto &LivenessAA = | ||||||||
1303 | getAAFor<AAIsDead>(QueryingAA, QueryIRP, DepClassTy::NONE); | ||||||||
1304 | |||||||||
1305 | for (Instruction *I : | ||||||||
1306 | InfoCache.getReadOrWriteInstsForFunction(*AssociatedFunction)) { | ||||||||
1307 | // Skip dead instructions. | ||||||||
1308 | if (isAssumedDead(IRPosition::value(*I), &QueryingAA, &LivenessAA, | ||||||||
1309 | UsedAssumedInformation)) | ||||||||
1310 | continue; | ||||||||
1311 | |||||||||
1312 | if (!Pred(*I)) | ||||||||
1313 | return false; | ||||||||
1314 | } | ||||||||
1315 | |||||||||
1316 | return true; | ||||||||
1317 | } | ||||||||
1318 | |||||||||
1319 | void Attributor::runTillFixpoint() { | ||||||||
1320 | TimeTraceScope TimeScope("Attributor::runTillFixpoint"); | ||||||||
1321 | LLVM_DEBUG(dbgs() << "[Attributor] Identified and initialized "do { } while (false) | ||||||||
1322 | << DG.SyntheticRoot.Deps.size()do { } while (false) | ||||||||
1323 | << " abstract attributes.\n")do { } while (false); | ||||||||
1324 | |||||||||
1325 | // Now that all abstract attributes are collected and initialized we start | ||||||||
1326 | // the abstract analysis. | ||||||||
1327 | |||||||||
1328 | unsigned IterationCounter = 1; | ||||||||
1329 | unsigned MaxFixedPointIterations; | ||||||||
1330 | if (MaxFixpointIterations) | ||||||||
1331 | MaxFixedPointIterations = MaxFixpointIterations.getValue(); | ||||||||
1332 | else | ||||||||
1333 | MaxFixedPointIterations = SetFixpointIterations; | ||||||||
1334 | |||||||||
1335 | SmallVector<AbstractAttribute *, 32> ChangedAAs; | ||||||||
1336 | SetVector<AbstractAttribute *> Worklist, InvalidAAs; | ||||||||
1337 | Worklist.insert(DG.SyntheticRoot.begin(), DG.SyntheticRoot.end()); | ||||||||
1338 | |||||||||
1339 | do { | ||||||||
1340 | // Remember the size to determine new attributes. | ||||||||
1341 | size_t NumAAs = DG.SyntheticRoot.Deps.size(); | ||||||||
1342 | LLVM_DEBUG(dbgs() << "\n\n[Attributor] #Iteration: " << IterationCounterdo { } while (false) | ||||||||
1343 | << ", Worklist size: " << Worklist.size() << "\n")do { } while (false); | ||||||||
1344 | |||||||||
1345 | // For invalid AAs we can fix dependent AAs that have a required dependence, | ||||||||
1346 | // thereby folding long dependence chains in a single step without the need | ||||||||
1347 | // to run updates. | ||||||||
1348 | for (unsigned u = 0; u < InvalidAAs.size(); ++u) { | ||||||||
1349 | AbstractAttribute *InvalidAA = InvalidAAs[u]; | ||||||||
1350 | |||||||||
1351 | // Check the dependences to fast track invalidation. | ||||||||
1352 | LLVM_DEBUG(dbgs() << "[Attributor] InvalidAA: " << *InvalidAA << " has "do { } while (false) | ||||||||
1353 | << InvalidAA->Deps.size()do { } while (false) | ||||||||
1354 | << " required & optional dependences\n")do { } while (false); | ||||||||
1355 | while (!InvalidAA->Deps.empty()) { | ||||||||
1356 | const auto &Dep = InvalidAA->Deps.back(); | ||||||||
1357 | InvalidAA->Deps.pop_back(); | ||||||||
1358 | AbstractAttribute *DepAA = cast<AbstractAttribute>(Dep.getPointer()); | ||||||||
1359 | if (Dep.getInt() == unsigned(DepClassTy::OPTIONAL)) { | ||||||||
1360 | Worklist.insert(DepAA); | ||||||||
1361 | continue; | ||||||||
1362 | } | ||||||||
1363 | DepAA->getState().indicatePessimisticFixpoint(); | ||||||||
1364 | assert(DepAA->getState().isAtFixpoint() && "Expected fixpoint state!")((void)0); | ||||||||
1365 | if (!DepAA->getState().isValidState()) | ||||||||
1366 | InvalidAAs.insert(DepAA); | ||||||||
1367 | else | ||||||||
1368 | ChangedAAs.push_back(DepAA); | ||||||||
1369 | } | ||||||||
1370 | } | ||||||||
1371 | |||||||||
1372 | // Add all abstract attributes that are potentially dependent on one that | ||||||||
1373 | // changed to the work list. | ||||||||
1374 | for (AbstractAttribute *ChangedAA : ChangedAAs) | ||||||||
1375 | while (!ChangedAA->Deps.empty()) { | ||||||||
1376 | Worklist.insert( | ||||||||
1377 | cast<AbstractAttribute>(ChangedAA->Deps.back().getPointer())); | ||||||||
1378 | ChangedAA->Deps.pop_back(); | ||||||||
1379 | } | ||||||||
1380 | |||||||||
1381 | LLVM_DEBUG(dbgs() << "[Attributor] #Iteration: " << IterationCounterdo { } while (false) | ||||||||
1382 | << ", Worklist+Dependent size: " << Worklist.size()do { } while (false) | ||||||||
1383 | << "\n")do { } while (false); | ||||||||
1384 | |||||||||
1385 | // Reset the changed and invalid set. | ||||||||
1386 | ChangedAAs.clear(); | ||||||||
1387 | InvalidAAs.clear(); | ||||||||
1388 | |||||||||
1389 | // Update all abstract attribute in the work list and record the ones that | ||||||||
1390 | // changed. | ||||||||
1391 | for (AbstractAttribute *AA : Worklist) { | ||||||||
1392 | const auto &AAState = AA->getState(); | ||||||||
1393 | if (!AAState.isAtFixpoint()) | ||||||||
1394 | if (updateAA(*AA) == ChangeStatus::CHANGED) | ||||||||
1395 | ChangedAAs.push_back(AA); | ||||||||
1396 | |||||||||
1397 | // Use the InvalidAAs vector to propagate invalid states fast transitively | ||||||||
1398 | // without requiring updates. | ||||||||
1399 | if (!AAState.isValidState()) | ||||||||
1400 | InvalidAAs.insert(AA); | ||||||||
1401 | } | ||||||||
1402 | |||||||||
1403 | // Add attributes to the changed set if they have been created in the last | ||||||||
1404 | // iteration. | ||||||||
1405 | ChangedAAs.append(DG.SyntheticRoot.begin() + NumAAs, | ||||||||
1406 | DG.SyntheticRoot.end()); | ||||||||
1407 | |||||||||
1408 | // Reset the work list and repopulate with the changed abstract attributes. | ||||||||
1409 | // Note that dependent ones are added above. | ||||||||
1410 | Worklist.clear(); | ||||||||
1411 | Worklist.insert(ChangedAAs.begin(), ChangedAAs.end()); | ||||||||
1412 | |||||||||
1413 | } while (!Worklist.empty() && (IterationCounter++ < MaxFixedPointIterations || | ||||||||
1414 | VerifyMaxFixpointIterations)); | ||||||||
1415 | |||||||||
1416 | LLVM_DEBUG(dbgs() << "\n[Attributor] Fixpoint iteration done after: "do { } while (false) | ||||||||
1417 | << IterationCounter << "/" << MaxFixpointIterationsdo { } while (false) | ||||||||
1418 | << " iterations\n")do { } while (false); | ||||||||
1419 | |||||||||
1420 | // Reset abstract arguments not settled in a sound fixpoint by now. This | ||||||||
1421 | // happens when we stopped the fixpoint iteration early. Note that only the | ||||||||
1422 | // ones marked as "changed" *and* the ones transitively depending on them | ||||||||
1423 | // need to be reverted to a pessimistic state. Others might not be in a | ||||||||
1424 | // fixpoint state but we can use the optimistic results for them anyway. | ||||||||
1425 | SmallPtrSet<AbstractAttribute *, 32> Visited; | ||||||||
1426 | for (unsigned u = 0; u < ChangedAAs.size(); u++) { | ||||||||
1427 | AbstractAttribute *ChangedAA = ChangedAAs[u]; | ||||||||
1428 | if (!Visited.insert(ChangedAA).second) | ||||||||
1429 | continue; | ||||||||
1430 | |||||||||
1431 | AbstractState &State = ChangedAA->getState(); | ||||||||
1432 | if (!State.isAtFixpoint()) { | ||||||||
1433 | State.indicatePessimisticFixpoint(); | ||||||||
1434 | |||||||||
1435 | NumAttributesTimedOut++; | ||||||||
1436 | } | ||||||||
1437 | |||||||||
1438 | while (!ChangedAA->Deps.empty()) { | ||||||||
1439 | ChangedAAs.push_back( | ||||||||
1440 | cast<AbstractAttribute>(ChangedAA->Deps.back().getPointer())); | ||||||||
1441 | ChangedAA->Deps.pop_back(); | ||||||||
1442 | } | ||||||||
1443 | } | ||||||||
1444 | |||||||||
1445 | LLVM_DEBUG({do { } while (false) | ||||||||
1446 | if (!Visited.empty())do { } while (false) | ||||||||
1447 | dbgs() << "\n[Attributor] Finalized " << Visited.size()do { } while (false) | ||||||||
1448 | << " abstract attributes.\n";do { } while (false) | ||||||||
1449 | })do { } while (false); | ||||||||
1450 | |||||||||
1451 | if (VerifyMaxFixpointIterations && | ||||||||
1452 | IterationCounter != MaxFixedPointIterations) { | ||||||||
1453 | errs() << "\n[Attributor] Fixpoint iteration done after: " | ||||||||
1454 | << IterationCounter << "/" << MaxFixedPointIterations | ||||||||
1455 | << " iterations\n"; | ||||||||
1456 | llvm_unreachable("The fixpoint was not reached with exactly the number of "__builtin_unreachable() | ||||||||
1457 | "specified iterations!")__builtin_unreachable(); | ||||||||
1458 | } | ||||||||
1459 | } | ||||||||
1460 | |||||||||
1461 | ChangeStatus Attributor::manifestAttributes() { | ||||||||
1462 | TimeTraceScope TimeScope("Attributor::manifestAttributes"); | ||||||||
1463 | size_t NumFinalAAs = DG.SyntheticRoot.Deps.size(); | ||||||||
1464 | |||||||||
1465 | unsigned NumManifested = 0; | ||||||||
1466 | unsigned NumAtFixpoint = 0; | ||||||||
1467 | ChangeStatus ManifestChange = ChangeStatus::UNCHANGED; | ||||||||
1468 | for (auto &DepAA : DG.SyntheticRoot.Deps) { | ||||||||
1469 | AbstractAttribute *AA = cast<AbstractAttribute>(DepAA.getPointer()); | ||||||||
1470 | AbstractState &State = AA->getState(); | ||||||||
1471 | |||||||||
1472 | // If there is not already a fixpoint reached, we can now take the | ||||||||
1473 | // optimistic state. This is correct because we enforced a pessimistic one | ||||||||
1474 | // on abstract attributes that were transitively dependent on a changed one | ||||||||
1475 | // already above. | ||||||||
1476 | if (!State.isAtFixpoint()) | ||||||||
1477 | State.indicateOptimisticFixpoint(); | ||||||||
1478 | |||||||||
1479 | // We must not manifest Attributes that use Callbase info. | ||||||||
1480 | if (AA->hasCallBaseContext()) | ||||||||
1481 | continue; | ||||||||
1482 | // If the state is invalid, we do not try to manifest it. | ||||||||
1483 | if (!State.isValidState()) | ||||||||
1484 | continue; | ||||||||
1485 | |||||||||
1486 | // Skip dead code. | ||||||||
1487 | bool UsedAssumedInformation = false; | ||||||||
1488 | if (isAssumedDead(*AA, nullptr, UsedAssumedInformation, | ||||||||
1489 | /* CheckBBLivenessOnly */ true)) | ||||||||
1490 | continue; | ||||||||
1491 | // Check if the manifest debug counter that allows skipping manifestation of | ||||||||
1492 | // AAs | ||||||||
1493 | if (!DebugCounter::shouldExecute(ManifestDBGCounter)) | ||||||||
1494 | continue; | ||||||||
1495 | // Manifest the state and record if we changed the IR. | ||||||||
1496 | ChangeStatus LocalChange = AA->manifest(*this); | ||||||||
1497 | if (LocalChange == ChangeStatus::CHANGED && AreStatisticsEnabled()) | ||||||||
1498 | AA->trackStatistics(); | ||||||||
1499 | LLVM_DEBUG(dbgs() << "[Attributor] Manifest " << LocalChange << " : " << *AAdo { } while (false) | ||||||||
1500 | << "\n")do { } while (false); | ||||||||
1501 | |||||||||
1502 | ManifestChange = ManifestChange | LocalChange; | ||||||||
1503 | |||||||||
1504 | NumAtFixpoint++; | ||||||||
1505 | NumManifested += (LocalChange == ChangeStatus::CHANGED); | ||||||||
1506 | } | ||||||||
1507 | |||||||||
1508 | (void)NumManifested; | ||||||||
1509 | (void)NumAtFixpoint; | ||||||||
1510 | LLVM_DEBUG(dbgs() << "\n[Attributor] Manifested " << NumManifesteddo { } while (false) | ||||||||
1511 | << " arguments while " << NumAtFixpointdo { } while (false) | ||||||||
1512 | << " were in a valid fixpoint state\n")do { } while (false); | ||||||||
1513 | |||||||||
1514 | NumAttributesManifested += NumManifested; | ||||||||
1515 | NumAttributesValidFixpoint += NumAtFixpoint; | ||||||||
1516 | |||||||||
1517 | (void)NumFinalAAs; | ||||||||
1518 | if (NumFinalAAs != DG.SyntheticRoot.Deps.size()) { | ||||||||
1519 | for (unsigned u = NumFinalAAs; u < DG.SyntheticRoot.Deps.size(); ++u) | ||||||||
1520 | errs() << "Unexpected abstract attribute: " | ||||||||
1521 | << cast<AbstractAttribute>(DG.SyntheticRoot.Deps[u].getPointer()) | ||||||||
1522 | << " :: " | ||||||||
1523 | << cast<AbstractAttribute>(DG.SyntheticRoot.Deps[u].getPointer()) | ||||||||
1524 | ->getIRPosition() | ||||||||
1525 | .getAssociatedValue() | ||||||||
1526 | << "\n"; | ||||||||
1527 | llvm_unreachable("Expected the final number of abstract attributes to "__builtin_unreachable() | ||||||||
1528 | "remain unchanged!")__builtin_unreachable(); | ||||||||
1529 | } | ||||||||
1530 | return ManifestChange; | ||||||||
1531 | } | ||||||||
1532 | |||||||||
1533 | void Attributor::identifyDeadInternalFunctions() { | ||||||||
1534 | // Early exit if we don't intend to delete functions. | ||||||||
1535 | if (!DeleteFns) | ||||||||
1536 | return; | ||||||||
1537 | |||||||||
1538 | // Identify dead internal functions and delete them. This happens outside | ||||||||
1539 | // the other fixpoint analysis as we might treat potentially dead functions | ||||||||
1540 | // as live to lower the number of iterations. If they happen to be dead, the | ||||||||
1541 | // below fixpoint loop will identify and eliminate them. | ||||||||
1542 | SmallVector<Function *, 8> InternalFns; | ||||||||
1543 | for (Function *F : Functions) | ||||||||
1544 | if (F->hasLocalLinkage()) | ||||||||
1545 | InternalFns.push_back(F); | ||||||||
1546 | |||||||||
1547 | SmallPtrSet<Function *, 8> LiveInternalFns; | ||||||||
1548 | bool FoundLiveInternal = true; | ||||||||
1549 | while (FoundLiveInternal) { | ||||||||
1550 | FoundLiveInternal = false; | ||||||||
1551 | for (unsigned u = 0, e = InternalFns.size(); u < e; ++u) { | ||||||||
1552 | Function *F = InternalFns[u]; | ||||||||
1553 | if (!F) | ||||||||
1554 | continue; | ||||||||
1555 | |||||||||
1556 | bool AllCallSitesKnown; | ||||||||
1557 | if (checkForAllCallSites( | ||||||||
1558 | [&](AbstractCallSite ACS) { | ||||||||
1559 | Function *Callee = ACS.getInstruction()->getFunction(); | ||||||||
1560 | return ToBeDeletedFunctions.count(Callee) || | ||||||||
1561 | (Functions.count(Callee) && Callee->hasLocalLinkage() && | ||||||||
1562 | !LiveInternalFns.count(Callee)); | ||||||||
1563 | }, | ||||||||
1564 | *F, true, nullptr, AllCallSitesKnown)) { | ||||||||
1565 | continue; | ||||||||
1566 | } | ||||||||
1567 | |||||||||
1568 | LiveInternalFns.insert(F); | ||||||||
1569 | InternalFns[u] = nullptr; | ||||||||
1570 | FoundLiveInternal = true; | ||||||||
1571 | } | ||||||||
1572 | } | ||||||||
1573 | |||||||||
1574 | for (unsigned u = 0, e = InternalFns.size(); u < e; ++u) | ||||||||
1575 | if (Function *F = InternalFns[u]) | ||||||||
1576 | ToBeDeletedFunctions.insert(F); | ||||||||
1577 | } | ||||||||
1578 | |||||||||
1579 | ChangeStatus Attributor::cleanupIR() { | ||||||||
1580 | TimeTraceScope TimeScope("Attributor::cleanupIR"); | ||||||||
1581 | // Delete stuff at the end to avoid invalid references and a nice order. | ||||||||
1582 | LLVM_DEBUG(dbgs() << "\n[Attributor] Delete/replace at least "do { } while (false) | ||||||||
1583 | << ToBeDeletedFunctions.size() << " functions and "do { } while (false) | ||||||||
1584 | << ToBeDeletedBlocks.size() << " blocks and "do { } while (false) | ||||||||
1585 | << ToBeDeletedInsts.size() << " instructions and "do { } while (false) | ||||||||
1586 | << ToBeChangedValues.size() << " values and "do { } while (false) | ||||||||
1587 | << ToBeChangedUses.size() << " uses. "do { } while (false) | ||||||||
1588 | << "Preserve manifest added " << ManifestAddedBlocks.size()do { } while (false) | ||||||||
1589 | << " blocks\n")do { } while (false); | ||||||||
1590 | |||||||||
1591 | SmallVector<WeakTrackingVH, 32> DeadInsts; | ||||||||
1592 | SmallVector<Instruction *, 32> TerminatorsToFold; | ||||||||
1593 | |||||||||
1594 | auto ReplaceUse = [&](Use *U, Value *NewV) { | ||||||||
1595 | Value *OldV = U->get(); | ||||||||
1596 | |||||||||
1597 | // If we plan to replace NewV we need to update it at this point. | ||||||||
1598 | do { | ||||||||
1599 | const auto &Entry = ToBeChangedValues.lookup(NewV); | ||||||||
1600 | if (!Entry.first) | ||||||||
1601 | break; | ||||||||
1602 | NewV = Entry.first; | ||||||||
1603 | } while (true); | ||||||||
1604 | |||||||||
1605 | // Do not replace uses in returns if the value is a must-tail call we will | ||||||||
1606 | // not delete. | ||||||||
1607 | if (auto *RI = dyn_cast<ReturnInst>(U->getUser())) { | ||||||||
1608 | if (auto *CI = dyn_cast<CallInst>(OldV->stripPointerCasts())) | ||||||||
1609 | if (CI->isMustTailCall() && | ||||||||
1610 | (!ToBeDeletedInsts.count(CI) || !isRunOn(*CI->getCaller()))) | ||||||||
1611 | return; | ||||||||
1612 | // If we rewrite a return and the new value is not an argument, strip the | ||||||||
1613 | // `returned` attribute as it is wrong now. | ||||||||
1614 | if (!isa<Argument>(NewV)) | ||||||||
1615 | for (auto &Arg : RI->getFunction()->args()) | ||||||||
1616 | Arg.removeAttr(Attribute::Returned); | ||||||||
1617 | } | ||||||||
1618 | |||||||||
1619 | // Do not perform call graph altering changes outside the SCC. | ||||||||
1620 | if (auto *CB = dyn_cast<CallBase>(U->getUser())) | ||||||||
1621 | if (CB->isCallee(U) && !isRunOn(*CB->getCaller())) | ||||||||
1622 | return; | ||||||||
1623 | |||||||||
1624 | LLVM_DEBUG(dbgs() << "Use " << *NewV << " in " << *U->getUser()do { } while (false) | ||||||||
1625 | << " instead of " << *OldV << "\n")do { } while (false); | ||||||||
1626 | U->set(NewV); | ||||||||
1627 | |||||||||
1628 | if (Instruction *I = dyn_cast<Instruction>(OldV)) { | ||||||||
1629 | CGModifiedFunctions.insert(I->getFunction()); | ||||||||
1630 | if (!isa<PHINode>(I) && !ToBeDeletedInsts.count(I) && | ||||||||
1631 | isInstructionTriviallyDead(I)) | ||||||||
1632 | DeadInsts.push_back(I); | ||||||||
1633 | } | ||||||||
1634 | if (isa<UndefValue>(NewV) && isa<CallBase>(U->getUser())) { | ||||||||
1635 | auto *CB = cast<CallBase>(U->getUser()); | ||||||||
1636 | if (CB->isArgOperand(U)) { | ||||||||
1637 | unsigned Idx = CB->getArgOperandNo(U); | ||||||||
1638 | CB->removeParamAttr(Idx, Attribute::NoUndef); | ||||||||
1639 | Function *Fn = CB->getCalledFunction(); | ||||||||
1640 | if (Fn && Fn->arg_size() > Idx) | ||||||||
1641 | Fn->removeParamAttr(Idx, Attribute::NoUndef); | ||||||||
1642 | } | ||||||||
1643 | } | ||||||||
1644 | if (isa<Constant>(NewV) && isa<BranchInst>(U->getUser())) { | ||||||||
1645 | Instruction *UserI = cast<Instruction>(U->getUser()); | ||||||||
1646 | if (isa<UndefValue>(NewV)) { | ||||||||
1647 | ToBeChangedToUnreachableInsts.insert(UserI); | ||||||||
1648 | } else { | ||||||||
1649 | TerminatorsToFold.push_back(UserI); | ||||||||
1650 | } | ||||||||
1651 | } | ||||||||
1652 | }; | ||||||||
1653 | |||||||||
1654 | for (auto &It : ToBeChangedUses) { | ||||||||
1655 | Use *U = It.first; | ||||||||
1656 | Value *NewV = It.second; | ||||||||
1657 | ReplaceUse(U, NewV); | ||||||||
1658 | } | ||||||||
1659 | |||||||||
1660 | SmallVector<Use *, 4> Uses; | ||||||||
1661 | for (auto &It : ToBeChangedValues) { | ||||||||
1662 | Value *OldV = It.first; | ||||||||
1663 | auto &Entry = It.second; | ||||||||
1664 | Value *NewV = Entry.first; | ||||||||
1665 | Uses.clear(); | ||||||||
1666 | for (auto &U : OldV->uses()) | ||||||||
1667 | if (Entry.second || !U.getUser()->isDroppable()) | ||||||||
1668 | Uses.push_back(&U); | ||||||||
1669 | for (Use *U : Uses) | ||||||||
1670 | ReplaceUse(U, NewV); | ||||||||
1671 | } | ||||||||
1672 | |||||||||
1673 | for (auto &V : InvokeWithDeadSuccessor) | ||||||||
1674 | if (InvokeInst *II = dyn_cast_or_null<InvokeInst>(V)) { | ||||||||
1675 | assert(isRunOn(*II->getFunction()) &&((void)0) | ||||||||
1676 | "Cannot replace an invoke outside the current SCC!")((void)0); | ||||||||
1677 | bool UnwindBBIsDead = II->hasFnAttr(Attribute::NoUnwind); | ||||||||
1678 | bool NormalBBIsDead = II->hasFnAttr(Attribute::NoReturn); | ||||||||
1679 | bool Invoke2CallAllowed = | ||||||||
1680 | !AAIsDead::mayCatchAsynchronousExceptions(*II->getFunction()); | ||||||||
1681 | assert((UnwindBBIsDead || NormalBBIsDead) &&((void)0) | ||||||||
1682 | "Invoke does not have dead successors!")((void)0); | ||||||||
1683 | BasicBlock *BB = II->getParent(); | ||||||||
1684 | BasicBlock *NormalDestBB = II->getNormalDest(); | ||||||||
1685 | if (UnwindBBIsDead) { | ||||||||
1686 | Instruction *NormalNextIP = &NormalDestBB->front(); | ||||||||
1687 | if (Invoke2CallAllowed) { | ||||||||
1688 | changeToCall(II); | ||||||||
1689 | NormalNextIP = BB->getTerminator(); | ||||||||
1690 | } | ||||||||
1691 | if (NormalBBIsDead) | ||||||||
1692 | ToBeChangedToUnreachableInsts.insert(NormalNextIP); | ||||||||
1693 | } else { | ||||||||
1694 | assert(NormalBBIsDead && "Broken invariant!")((void)0); | ||||||||
1695 | if (!NormalDestBB->getUniquePredecessor()) | ||||||||
1696 | NormalDestBB = SplitBlockPredecessors(NormalDestBB, {BB}, ".dead"); | ||||||||
1697 | ToBeChangedToUnreachableInsts.insert(&NormalDestBB->front()); | ||||||||
1698 | } | ||||||||
1699 | } | ||||||||
1700 | for (Instruction *I : TerminatorsToFold) { | ||||||||
1701 | if (!isRunOn(*I->getFunction())) | ||||||||
1702 | continue; | ||||||||
1703 | CGModifiedFunctions.insert(I->getFunction()); | ||||||||
1704 | ConstantFoldTerminator(I->getParent()); | ||||||||
1705 | } | ||||||||
1706 | for (auto &V : ToBeChangedToUnreachableInsts) | ||||||||
1707 | if (Instruction *I = dyn_cast_or_null<Instruction>(V)) { | ||||||||
1708 | if (!isRunOn(*I->getFunction())) | ||||||||
1709 | continue; | ||||||||
1710 | CGModifiedFunctions.insert(I->getFunction()); | ||||||||
1711 | changeToUnreachable(I); | ||||||||
1712 | } | ||||||||
1713 | |||||||||
1714 | for (auto &V : ToBeDeletedInsts) { | ||||||||
1715 | if (Instruction *I = dyn_cast_or_null<Instruction>(V)) { | ||||||||
1716 | if (auto *CB = dyn_cast<CallBase>(I)) { | ||||||||
1717 | if (!isRunOn(*I->getFunction())) | ||||||||
1718 | continue; | ||||||||
1719 | if (!isa<IntrinsicInst>(CB)) | ||||||||
1720 | CGUpdater.removeCallSite(*CB); | ||||||||
1721 | } | ||||||||
1722 | I->dropDroppableUses(); | ||||||||
1723 | CGModifiedFunctions.insert(I->getFunction()); | ||||||||
1724 | if (!I->getType()->isVoidTy()) | ||||||||
1725 | I->replaceAllUsesWith(UndefValue::get(I->getType())); | ||||||||
1726 | if (!isa<PHINode>(I) && isInstructionTriviallyDead(I)) | ||||||||
1727 | DeadInsts.push_back(I); | ||||||||
1728 | else | ||||||||
1729 | I->eraseFromParent(); | ||||||||
1730 | } | ||||||||
1731 | } | ||||||||
1732 | |||||||||
1733 | llvm::erase_if(DeadInsts, [&](WeakTrackingVH I) { | ||||||||
1734 | return !I || !isRunOn(*cast<Instruction>(I)->getFunction()); | ||||||||
1735 | }); | ||||||||
1736 | |||||||||
1737 | LLVM_DEBUG({do { } while (false) | ||||||||
1738 | dbgs() << "[Attributor] DeadInsts size: " << DeadInsts.size() << "\n";do { } while (false) | ||||||||
1739 | for (auto &I : DeadInsts)do { } while (false) | ||||||||
1740 | if (I)do { } while (false) | ||||||||
1741 | dbgs() << " - " << *I << "\n";do { } while (false) | ||||||||
1742 | })do { } while (false); | ||||||||
1743 | |||||||||
1744 | RecursivelyDeleteTriviallyDeadInstructions(DeadInsts); | ||||||||
1745 | |||||||||
1746 | if (unsigned NumDeadBlocks = ToBeDeletedBlocks.size()) { | ||||||||
1747 | SmallVector<BasicBlock *, 8> ToBeDeletedBBs; | ||||||||
1748 | ToBeDeletedBBs.reserve(NumDeadBlocks); | ||||||||
1749 | for (BasicBlock *BB : ToBeDeletedBlocks) { | ||||||||
1750 | assert(isRunOn(*BB->getParent()) &&((void)0) | ||||||||
1751 | "Cannot delete a block outside the current SCC!")((void)0); | ||||||||
1752 | CGModifiedFunctions.insert(BB->getParent()); | ||||||||
1753 | // Do not delete BBs added during manifests of AAs. | ||||||||
1754 | if (ManifestAddedBlocks.contains(BB)) | ||||||||
1755 | continue; | ||||||||
1756 | ToBeDeletedBBs.push_back(BB); | ||||||||
1757 | } | ||||||||
1758 | // Actually we do not delete the blocks but squash them into a single | ||||||||
1759 | // unreachable but untangling branches that jump here is something we need | ||||||||
1760 | // to do in a more generic way. | ||||||||
1761 | DetatchDeadBlocks(ToBeDeletedBBs, nullptr); | ||||||||
1762 | } | ||||||||
1763 | |||||||||
1764 | identifyDeadInternalFunctions(); | ||||||||
1765 | |||||||||
1766 | // Rewrite the functions as requested during manifest. | ||||||||
1767 | ChangeStatus ManifestChange = rewriteFunctionSignatures(CGModifiedFunctions); | ||||||||
1768 | |||||||||
1769 | for (Function *Fn : CGModifiedFunctions) | ||||||||
1770 | if (!ToBeDeletedFunctions.count(Fn) && Functions.count(Fn)) | ||||||||
1771 | CGUpdater.reanalyzeFunction(*Fn); | ||||||||
1772 | |||||||||
1773 | for (Function *Fn : ToBeDeletedFunctions) { | ||||||||
1774 | if (!Functions.count(Fn)) | ||||||||
1775 | continue; | ||||||||
1776 | CGUpdater.removeFunction(*Fn); | ||||||||
1777 | } | ||||||||
1778 | |||||||||
1779 | if (!ToBeChangedUses.empty()) | ||||||||
1780 | ManifestChange = ChangeStatus::CHANGED; | ||||||||
1781 | |||||||||
1782 | if (!ToBeChangedToUnreachableInsts.empty()) | ||||||||
1783 | ManifestChange = ChangeStatus::CHANGED; | ||||||||
1784 | |||||||||
1785 | if (!ToBeDeletedFunctions.empty()) | ||||||||
1786 | ManifestChange = ChangeStatus::CHANGED; | ||||||||
1787 | |||||||||
1788 | if (!ToBeDeletedBlocks.empty()) | ||||||||
1789 | ManifestChange = ChangeStatus::CHANGED; | ||||||||
1790 | |||||||||
1791 | if (!ToBeDeletedInsts.empty()) | ||||||||
1792 | ManifestChange = ChangeStatus::CHANGED; | ||||||||
1793 | |||||||||
1794 | if (!InvokeWithDeadSuccessor.empty()) | ||||||||
1795 | ManifestChange = ChangeStatus::CHANGED; | ||||||||
1796 | |||||||||
1797 | if (!DeadInsts.empty()) | ||||||||
1798 | ManifestChange = ChangeStatus::CHANGED; | ||||||||
1799 | |||||||||
1800 | NumFnDeleted += ToBeDeletedFunctions.size(); | ||||||||
1801 | |||||||||
1802 | LLVM_DEBUG(dbgs() << "[Attributor] Deleted " << ToBeDeletedFunctions.size()do { } while (false) | ||||||||
1803 | << " functions after manifest.\n")do { } while (false); | ||||||||
1804 | |||||||||
1805 | #ifdef EXPENSIVE_CHECKS | ||||||||
1806 | for (Function *F : Functions) { | ||||||||
1807 | if (ToBeDeletedFunctions.count(F)) | ||||||||
1808 | continue; | ||||||||
1809 | assert(!verifyFunction(*F, &errs()) && "Module verification failed!")((void)0); | ||||||||
1810 | } | ||||||||
1811 | #endif | ||||||||
1812 | |||||||||
1813 | return ManifestChange; | ||||||||
1814 | } | ||||||||
1815 | |||||||||
1816 | ChangeStatus Attributor::run() { | ||||||||
1817 | TimeTraceScope TimeScope("Attributor::run"); | ||||||||
1818 | AttributorCallGraph ACallGraph(*this); | ||||||||
1819 | |||||||||
1820 | if (PrintCallGraph) | ||||||||
1821 | ACallGraph.populateAll(); | ||||||||
1822 | |||||||||
1823 | Phase = AttributorPhase::UPDATE; | ||||||||
1824 | runTillFixpoint(); | ||||||||
1825 | |||||||||
1826 | // dump graphs on demand | ||||||||
1827 | if (DumpDepGraph) | ||||||||
1828 | DG.dumpGraph(); | ||||||||
1829 | |||||||||
1830 | if (ViewDepGraph) | ||||||||
1831 | DG.viewGraph(); | ||||||||
1832 | |||||||||
1833 | if (PrintDependencies) | ||||||||
1834 | DG.print(); | ||||||||
1835 | |||||||||
1836 | Phase = AttributorPhase::MANIFEST; | ||||||||
1837 | ChangeStatus ManifestChange = manifestAttributes(); | ||||||||
1838 | |||||||||
1839 | Phase = AttributorPhase::CLEANUP; | ||||||||
1840 | ChangeStatus CleanupChange = cleanupIR(); | ||||||||
1841 | |||||||||
1842 | if (PrintCallGraph) | ||||||||
1843 | ACallGraph.print(); | ||||||||
1844 | |||||||||
1845 | return ManifestChange | CleanupChange; | ||||||||
1846 | } | ||||||||
1847 | |||||||||
1848 | ChangeStatus Attributor::updateAA(AbstractAttribute &AA) { | ||||||||
1849 | TimeTraceScope TimeScope( | ||||||||
1850 | AA.getName() + std::to_string(AA.getIRPosition().getPositionKind()) + | ||||||||
1851 | "::updateAA"); | ||||||||
1852 | assert(Phase == AttributorPhase::UPDATE &&((void)0) | ||||||||
1853 | "We can update AA only in the update stage!")((void)0); | ||||||||
1854 | |||||||||
1855 | // Use a new dependence vector for this update. | ||||||||
1856 | DependenceVector DV; | ||||||||
1857 | DependenceStack.push_back(&DV); | ||||||||
1858 | |||||||||
1859 | auto &AAState = AA.getState(); | ||||||||
1860 | ChangeStatus CS = ChangeStatus::UNCHANGED; | ||||||||
1861 | bool UsedAssumedInformation = false; | ||||||||
1862 | if (!isAssumedDead(AA, nullptr, UsedAssumedInformation, | ||||||||
1863 | /* CheckBBLivenessOnly */ true)) | ||||||||
1864 | CS = AA.update(*this); | ||||||||
1865 | |||||||||
1866 | if (DV.empty()) { | ||||||||
1867 | // If the attribute did not query any non-fix information, the state | ||||||||
1868 | // will not change and we can indicate that right away. | ||||||||
1869 | AAState.indicateOptimisticFixpoint(); | ||||||||
1870 | } | ||||||||
1871 | |||||||||
1872 | if (!AAState.isAtFixpoint()) | ||||||||
1873 | rememberDependences(); | ||||||||
1874 | |||||||||
1875 | // Verify the stack was used properly, that is we pop the dependence vector we | ||||||||
1876 | // put there earlier. | ||||||||
1877 | DependenceVector *PoppedDV = DependenceStack.pop_back_val(); | ||||||||
1878 | (void)PoppedDV; | ||||||||
1879 | assert(PoppedDV == &DV && "Inconsistent usage of the dependence stack!")((void)0); | ||||||||
1880 | |||||||||
1881 | return CS; | ||||||||
1882 | } | ||||||||
1883 | |||||||||
1884 | void Attributor::createShallowWrapper(Function &F) { | ||||||||
1885 | assert(!F.isDeclaration() && "Cannot create a wrapper around a declaration!")((void)0); | ||||||||
1886 | |||||||||
1887 | Module &M = *F.getParent(); | ||||||||
1888 | LLVMContext &Ctx = M.getContext(); | ||||||||
1889 | FunctionType *FnTy = F.getFunctionType(); | ||||||||
1890 | |||||||||
1891 | Function *Wrapper = | ||||||||
1892 | Function::Create(FnTy, F.getLinkage(), F.getAddressSpace(), F.getName()); | ||||||||
1893 | F.setName(""); // set the inside function anonymous | ||||||||
1894 | M.getFunctionList().insert(F.getIterator(), Wrapper); | ||||||||
1895 | |||||||||
1896 | F.setLinkage(GlobalValue::InternalLinkage); | ||||||||
1897 | |||||||||
1898 | F.replaceAllUsesWith(Wrapper); | ||||||||
1899 | assert(F.use_empty() && "Uses remained after wrapper was created!")((void)0); | ||||||||
1900 | |||||||||
1901 | // Move the COMDAT section to the wrapper. | ||||||||
1902 | // TODO: Check if we need to keep it for F as well. | ||||||||
1903 | Wrapper->setComdat(F.getComdat()); | ||||||||
1904 | F.setComdat(nullptr); | ||||||||
1905 | |||||||||
1906 | // Copy all metadata and attributes but keep them on F as well. | ||||||||
1907 | SmallVector<std::pair<unsigned, MDNode *>, 1> MDs; | ||||||||
1908 | F.getAllMetadata(MDs); | ||||||||
1909 | for (auto MDIt : MDs) | ||||||||
1910 | Wrapper->addMetadata(MDIt.first, *MDIt.second); | ||||||||
1911 | Wrapper->setAttributes(F.getAttributes()); | ||||||||
1912 | |||||||||
1913 | // Create the call in the wrapper. | ||||||||
1914 | BasicBlock *EntryBB = BasicBlock::Create(Ctx, "entry", Wrapper); | ||||||||
1915 | |||||||||
1916 | SmallVector<Value *, 8> Args; | ||||||||
1917 | Argument *FArgIt = F.arg_begin(); | ||||||||
1918 | for (Argument &Arg : Wrapper->args()) { | ||||||||
1919 | Args.push_back(&Arg); | ||||||||
1920 | Arg.setName((FArgIt++)->getName()); | ||||||||
1921 | } | ||||||||
1922 | |||||||||
1923 | CallInst *CI = CallInst::Create(&F, Args, "", EntryBB); | ||||||||
1924 | CI->setTailCall(true); | ||||||||
1925 | CI->addAttribute(AttributeList::FunctionIndex, Attribute::NoInline); | ||||||||
1926 | ReturnInst::Create(Ctx, CI->getType()->isVoidTy() ? nullptr : CI, EntryBB); | ||||||||
1927 | |||||||||
1928 | NumFnShallowWrappersCreated++; | ||||||||
1929 | } | ||||||||
1930 | |||||||||
1931 | bool Attributor::isInternalizable(Function &F) { | ||||||||
1932 | if (F.isDeclaration() || F.hasLocalLinkage() || | ||||||||
1933 | GlobalValue::isInterposableLinkage(F.getLinkage())) | ||||||||
1934 | return false; | ||||||||
1935 | return true; | ||||||||
1936 | } | ||||||||
1937 | |||||||||
1938 | Function *Attributor::internalizeFunction(Function &F, bool Force) { | ||||||||
1939 | if (!AllowDeepWrapper && !Force) | ||||||||
1940 | return nullptr; | ||||||||
1941 | if (!isInternalizable(F)) | ||||||||
1942 | return nullptr; | ||||||||
1943 | |||||||||
1944 | SmallPtrSet<Function *, 2> FnSet = {&F}; | ||||||||
1945 | DenseMap<Function *, Function *> InternalizedFns; | ||||||||
1946 | internalizeFunctions(FnSet, InternalizedFns); | ||||||||
1947 | |||||||||
1948 | return InternalizedFns[&F]; | ||||||||
1949 | } | ||||||||
1950 | |||||||||
1951 | bool Attributor::internalizeFunctions(SmallPtrSetImpl<Function *> &FnSet, | ||||||||
1952 | DenseMap<Function *, Function *> &FnMap) { | ||||||||
1953 | for (Function *F : FnSet) | ||||||||
1954 | if (!Attributor::isInternalizable(*F)) | ||||||||
1955 | return false; | ||||||||
1956 | |||||||||
1957 | FnMap.clear(); | ||||||||
1958 | // Generate the internalized version of each function. | ||||||||
1959 | for (Function *F : FnSet) { | ||||||||
1960 | Module &M = *F->getParent(); | ||||||||
1961 | FunctionType *FnTy = F->getFunctionType(); | ||||||||
1962 | |||||||||
1963 | // Create a copy of the current function | ||||||||
1964 | Function *Copied = | ||||||||
1965 | Function::Create(FnTy, F->getLinkage(), F->getAddressSpace(), | ||||||||
1966 | F->getName() + ".internalized"); | ||||||||
1967 | ValueToValueMapTy VMap; | ||||||||
1968 | auto *NewFArgIt = Copied->arg_begin(); | ||||||||
1969 | for (auto &Arg : F->args()) { | ||||||||
1970 | auto ArgName = Arg.getName(); | ||||||||
1971 | NewFArgIt->setName(ArgName); | ||||||||
1972 | VMap[&Arg] = &(*NewFArgIt++); | ||||||||
1973 | } | ||||||||
1974 | SmallVector<ReturnInst *, 8> Returns; | ||||||||
1975 | |||||||||
1976 | // Copy the body of the original function to the new one | ||||||||
1977 | CloneFunctionInto(Copied, F, VMap, | ||||||||
1978 | CloneFunctionChangeType::LocalChangesOnly, Returns); | ||||||||
1979 | |||||||||
1980 | // Set the linakage and visibility late as CloneFunctionInto has some | ||||||||
1981 | // implicit requirements. | ||||||||
1982 | Copied->setVisibility(GlobalValue::DefaultVisibility); | ||||||||
1983 | Copied->setLinkage(GlobalValue::PrivateLinkage); | ||||||||
1984 | |||||||||
1985 | // Copy metadata | ||||||||
1986 | SmallVector<std::pair<unsigned, MDNode *>, 1> MDs; | ||||||||
1987 | F->getAllMetadata(MDs); | ||||||||
1988 | for (auto MDIt : MDs) | ||||||||
1989 | if (!Copied->hasMetadata()) | ||||||||
1990 | Copied->addMetadata(MDIt.first, *MDIt.second); | ||||||||
1991 | |||||||||
1992 | M.getFunctionList().insert(F->getIterator(), Copied); | ||||||||
1993 | Copied->setDSOLocal(true); | ||||||||
1994 | FnMap[F] = Copied; | ||||||||
1995 | } | ||||||||
1996 | |||||||||
1997 | // Replace all uses of the old function with the new internalized function | ||||||||
1998 | // unless the caller is a function that was just internalized. | ||||||||
1999 | for (Function *F : FnSet) { | ||||||||
2000 | auto &InternalizedFn = FnMap[F]; | ||||||||
2001 | auto IsNotInternalized = [&](Use &U) -> bool { | ||||||||
2002 | if (auto *CB = dyn_cast<CallBase>(U.getUser())) | ||||||||
2003 | return !FnMap.lookup(CB->getCaller()); | ||||||||
2004 | return false; | ||||||||
2005 | }; | ||||||||
2006 | F->replaceUsesWithIf(InternalizedFn, IsNotInternalized); | ||||||||
2007 | } | ||||||||
2008 | |||||||||
2009 | return true; | ||||||||
2010 | } | ||||||||
2011 | |||||||||
2012 | bool Attributor::isValidFunctionSignatureRewrite( | ||||||||
2013 | Argument &Arg, ArrayRef<Type *> ReplacementTypes) { | ||||||||
2014 | |||||||||
2015 | if (!RewriteSignatures) | ||||||||
2016 | return false; | ||||||||
2017 | |||||||||
2018 | auto CallSiteCanBeChanged = [](AbstractCallSite ACS) { | ||||||||
2019 | // Forbid the call site to cast the function return type. If we need to | ||||||||
2020 | // rewrite these functions we need to re-create a cast for the new call site | ||||||||
2021 | // (if the old had uses). | ||||||||
2022 | if (!ACS.getCalledFunction() || | ||||||||
2023 | ACS.getInstruction()->getType() != | ||||||||
2024 | ACS.getCalledFunction()->getReturnType()) | ||||||||
2025 | return false; | ||||||||
2026 | // Forbid must-tail calls for now. | ||||||||
2027 | return !ACS.isCallbackCall() && !ACS.getInstruction()->isMustTailCall(); | ||||||||
2028 | }; | ||||||||
2029 | |||||||||
2030 | Function *Fn = Arg.getParent(); | ||||||||
2031 | // Avoid var-arg functions for now. | ||||||||
2032 | if (Fn->isVarArg()) { | ||||||||
2033 | LLVM_DEBUG(dbgs() << "[Attributor] Cannot rewrite var-args functions\n")do { } while (false); | ||||||||
2034 | return false; | ||||||||
2035 | } | ||||||||
2036 | |||||||||
2037 | // Avoid functions with complicated argument passing semantics. | ||||||||
2038 | AttributeList FnAttributeList = Fn->getAttributes(); | ||||||||
2039 | if (FnAttributeList.hasAttrSomewhere(Attribute::Nest) || | ||||||||
2040 | FnAttributeList.hasAttrSomewhere(Attribute::StructRet) || | ||||||||
2041 | FnAttributeList.hasAttrSomewhere(Attribute::InAlloca) || | ||||||||
2042 | FnAttributeList.hasAttrSomewhere(Attribute::Preallocated)) { | ||||||||
2043 | LLVM_DEBUG(do { } while (false) | ||||||||
2044 | dbgs() << "[Attributor] Cannot rewrite due to complex attribute\n")do { } while (false); | ||||||||
2045 | return false; | ||||||||
2046 | } | ||||||||
2047 | |||||||||
2048 | // Avoid callbacks for now. | ||||||||
2049 | bool AllCallSitesKnown; | ||||||||
2050 | if (!checkForAllCallSites(CallSiteCanBeChanged, *Fn, true, nullptr, | ||||||||
2051 | AllCallSitesKnown)) { | ||||||||
2052 | LLVM_DEBUG(dbgs() << "[Attributor] Cannot rewrite all call sites\n")do { } while (false); | ||||||||
2053 | return false; | ||||||||
2054 | } | ||||||||
2055 | |||||||||
2056 | auto InstPred = [](Instruction &I) { | ||||||||
2057 | if (auto *CI = dyn_cast<CallInst>(&I)) | ||||||||
2058 | return !CI->isMustTailCall(); | ||||||||
2059 | return true; | ||||||||
2060 | }; | ||||||||
2061 | |||||||||
2062 | // Forbid must-tail calls for now. | ||||||||
2063 | // TODO: | ||||||||
2064 | bool UsedAssumedInformation = false; | ||||||||
2065 | auto &OpcodeInstMap = InfoCache.getOpcodeInstMapForFunction(*Fn); | ||||||||
2066 | if (!checkForAllInstructionsImpl(nullptr, OpcodeInstMap, InstPred, nullptr, | ||||||||
2067 | nullptr, {Instruction::Call}, | ||||||||
2068 | UsedAssumedInformation)) { | ||||||||
2069 | LLVM_DEBUG(dbgs() << "[Attributor] Cannot rewrite due to instructions\n")do { } while (false); | ||||||||
2070 | return false; | ||||||||
2071 | } | ||||||||
2072 | |||||||||
2073 | return true; | ||||||||
2074 | } | ||||||||
2075 | |||||||||
2076 | bool Attributor::registerFunctionSignatureRewrite( | ||||||||
2077 | Argument &Arg, ArrayRef<Type *> ReplacementTypes, | ||||||||
2078 | ArgumentReplacementInfo::CalleeRepairCBTy &&CalleeRepairCB, | ||||||||
2079 | ArgumentReplacementInfo::ACSRepairCBTy &&ACSRepairCB) { | ||||||||
2080 | LLVM_DEBUG(dbgs() << "[Attributor] Register new rewrite of " << Arg << " in "do { } while (false) | ||||||||
2081 | << Arg.getParent()->getName() << " with "do { } while (false) | ||||||||
2082 | << ReplacementTypes.size() << " replacements\n")do { } while (false); | ||||||||
2083 | assert(isValidFunctionSignatureRewrite(Arg, ReplacementTypes) &&((void)0) | ||||||||
2084 | "Cannot register an invalid rewrite")((void)0); | ||||||||
2085 | |||||||||
2086 | Function *Fn = Arg.getParent(); | ||||||||
2087 | SmallVectorImpl<std::unique_ptr<ArgumentReplacementInfo>> &ARIs = | ||||||||
2088 | ArgumentReplacementMap[Fn]; | ||||||||
2089 | if (ARIs.empty()) | ||||||||
2090 | ARIs.resize(Fn->arg_size()); | ||||||||
2091 | |||||||||
2092 | // If we have a replacement already with less than or equal new arguments, | ||||||||
2093 | // ignore this request. | ||||||||
2094 | std::unique_ptr<ArgumentReplacementInfo> &ARI = ARIs[Arg.getArgNo()]; | ||||||||
2095 | if (ARI && ARI->getNumReplacementArgs() <= ReplacementTypes.size()) { | ||||||||
2096 | LLVM_DEBUG(dbgs() << "[Attributor] Existing rewrite is preferred\n")do { } while (false); | ||||||||
2097 | return false; | ||||||||
2098 | } | ||||||||
2099 | |||||||||
2100 | // If we have a replacement already but we like the new one better, delete | ||||||||
2101 | // the old. | ||||||||
2102 | ARI.reset(); | ||||||||
2103 | |||||||||
2104 | LLVM_DEBUG(dbgs() << "[Attributor] Register new rewrite of " << Arg << " in "do { } while (false) | ||||||||
2105 | << Arg.getParent()->getName() << " with "do { } while (false) | ||||||||
2106 | << ReplacementTypes.size() << " replacements\n")do { } while (false); | ||||||||
2107 | |||||||||
2108 | // Remember the replacement. | ||||||||
2109 | ARI.reset(new ArgumentReplacementInfo(*this, Arg, ReplacementTypes, | ||||||||
2110 | std::move(CalleeRepairCB), | ||||||||
2111 | std::move(ACSRepairCB))); | ||||||||
2112 | |||||||||
2113 | return true; | ||||||||
2114 | } | ||||||||
2115 | |||||||||
2116 | bool Attributor::shouldSeedAttribute(AbstractAttribute &AA) { | ||||||||
2117 | bool Result = true; | ||||||||
2118 | #ifndef NDEBUG1 | ||||||||
2119 | if (SeedAllowList.size() != 0) | ||||||||
2120 | Result = | ||||||||
2121 | std::count(SeedAllowList.begin(), SeedAllowList.end(), AA.getName()); | ||||||||
2122 | Function *Fn = AA.getAnchorScope(); | ||||||||
2123 | if (FunctionSeedAllowList.size() != 0 && Fn) | ||||||||
2124 | Result &= std::count(FunctionSeedAllowList.begin(), | ||||||||
2125 | FunctionSeedAllowList.end(), Fn->getName()); | ||||||||
2126 | #endif | ||||||||
2127 | return Result; | ||||||||
2128 | } | ||||||||
2129 | |||||||||
2130 | ChangeStatus Attributor::rewriteFunctionSignatures( | ||||||||
2131 | SmallPtrSetImpl<Function *> &ModifiedFns) { | ||||||||
2132 | ChangeStatus Changed = ChangeStatus::UNCHANGED; | ||||||||
2133 | |||||||||
2134 | for (auto &It : ArgumentReplacementMap) { | ||||||||
2135 | Function *OldFn = It.getFirst(); | ||||||||
2136 | |||||||||
2137 | // Deleted functions do not require rewrites. | ||||||||
2138 | if (!Functions.count(OldFn) || ToBeDeletedFunctions.count(OldFn)) | ||||||||
2139 | continue; | ||||||||
2140 | |||||||||
2141 | const SmallVectorImpl<std::unique_ptr<ArgumentReplacementInfo>> &ARIs = | ||||||||
2142 | It.getSecond(); | ||||||||
2143 | assert(ARIs.size() == OldFn->arg_size() && "Inconsistent state!")((void)0); | ||||||||
2144 | |||||||||
2145 | SmallVector<Type *, 16> NewArgumentTypes; | ||||||||
2146 | SmallVector<AttributeSet, 16> NewArgumentAttributes; | ||||||||
2147 | |||||||||
2148 | // Collect replacement argument types and copy over existing attributes. | ||||||||
2149 | AttributeList OldFnAttributeList = OldFn->getAttributes(); | ||||||||
2150 | for (Argument &Arg : OldFn->args()) { | ||||||||
2151 | if (const std::unique_ptr<ArgumentReplacementInfo> &ARI = | ||||||||
2152 | ARIs[Arg.getArgNo()]) { | ||||||||
2153 | NewArgumentTypes.append(ARI->ReplacementTypes.begin(), | ||||||||
2154 | ARI->ReplacementTypes.end()); | ||||||||
2155 | NewArgumentAttributes.append(ARI->getNumReplacementArgs(), | ||||||||
2156 | AttributeSet()); | ||||||||
2157 | } else { | ||||||||
2158 | NewArgumentTypes.push_back(Arg.getType()); | ||||||||
2159 | NewArgumentAttributes.push_back( | ||||||||
2160 | OldFnAttributeList.getParamAttributes(Arg.getArgNo())); | ||||||||
2161 | } | ||||||||
2162 | } | ||||||||
2163 | |||||||||
2164 | FunctionType *OldFnTy = OldFn->getFunctionType(); | ||||||||
2165 | Type *RetTy = OldFnTy->getReturnType(); | ||||||||
2166 | |||||||||
2167 | // Construct the new function type using the new arguments types. | ||||||||
2168 | FunctionType *NewFnTy = | ||||||||
2169 | FunctionType::get(RetTy, NewArgumentTypes, OldFnTy->isVarArg()); | ||||||||
2170 | |||||||||
2171 | LLVM_DEBUG(dbgs() << "[Attributor] Function rewrite '" << OldFn->getName()do { } while (false) | ||||||||
2172 | << "' from " << *OldFn->getFunctionType() << " to "do { } while (false) | ||||||||
2173 | << *NewFnTy << "\n")do { } while (false); | ||||||||
2174 | |||||||||
2175 | // Create the new function body and insert it into the module. | ||||||||
2176 | Function *NewFn = Function::Create(NewFnTy, OldFn->getLinkage(), | ||||||||
2177 | OldFn->getAddressSpace(), ""); | ||||||||
2178 | Functions.insert(NewFn); | ||||||||
2179 | OldFn->getParent()->getFunctionList().insert(OldFn->getIterator(), NewFn); | ||||||||
2180 | NewFn->takeName(OldFn); | ||||||||
2181 | NewFn->copyAttributesFrom(OldFn); | ||||||||
2182 | |||||||||
2183 | // Patch the pointer to LLVM function in debug info descriptor. | ||||||||
2184 | NewFn->setSubprogram(OldFn->getSubprogram()); | ||||||||
2185 | OldFn->setSubprogram(nullptr); | ||||||||
2186 | |||||||||
2187 | // Recompute the parameter attributes list based on the new arguments for | ||||||||
2188 | // the function. | ||||||||
2189 | LLVMContext &Ctx = OldFn->getContext(); | ||||||||
2190 | NewFn->setAttributes(AttributeList::get( | ||||||||
2191 | Ctx, OldFnAttributeList.getFnAttributes(), | ||||||||
2192 | OldFnAttributeList.getRetAttributes(), NewArgumentAttributes)); | ||||||||
2193 | |||||||||
2194 | // Since we have now created the new function, splice the body of the old | ||||||||
2195 | // function right into the new function, leaving the old rotting hulk of the | ||||||||
2196 | // function empty. | ||||||||
2197 | NewFn->getBasicBlockList().splice(NewFn->begin(), | ||||||||
2198 | OldFn->getBasicBlockList()); | ||||||||
2199 | |||||||||
2200 | // Fixup block addresses to reference new function. | ||||||||
2201 | SmallVector<BlockAddress *, 8u> BlockAddresses; | ||||||||
2202 | for (User *U : OldFn->users()) | ||||||||
2203 | if (auto *BA = dyn_cast<BlockAddress>(U)) | ||||||||
2204 | BlockAddresses.push_back(BA); | ||||||||
2205 | for (auto *BA : BlockAddresses) | ||||||||
2206 | BA->replaceAllUsesWith(BlockAddress::get(NewFn, BA->getBasicBlock())); | ||||||||
2207 | |||||||||
2208 | // Set of all "call-like" instructions that invoke the old function mapped | ||||||||
2209 | // to their new replacements. | ||||||||
2210 | SmallVector<std::pair<CallBase *, CallBase *>, 8> CallSitePairs; | ||||||||
2211 | |||||||||
2212 | // Callback to create a new "call-like" instruction for a given one. | ||||||||
2213 | auto CallSiteReplacementCreator = [&](AbstractCallSite ACS) { | ||||||||
2214 | CallBase *OldCB = cast<CallBase>(ACS.getInstruction()); | ||||||||
2215 | const AttributeList &OldCallAttributeList = OldCB->getAttributes(); | ||||||||
2216 | |||||||||
2217 | // Collect the new argument operands for the replacement call site. | ||||||||
2218 | SmallVector<Value *, 16> NewArgOperands; | ||||||||
2219 | SmallVector<AttributeSet, 16> NewArgOperandAttributes; | ||||||||
2220 | for (unsigned OldArgNum = 0; OldArgNum < ARIs.size(); ++OldArgNum) { | ||||||||
2221 | unsigned NewFirstArgNum = NewArgOperands.size(); | ||||||||
2222 | (void)NewFirstArgNum; // only used inside assert. | ||||||||
2223 | if (const std::unique_ptr<ArgumentReplacementInfo> &ARI = | ||||||||
2224 | ARIs[OldArgNum]) { | ||||||||
2225 | if (ARI->ACSRepairCB) | ||||||||
2226 | ARI->ACSRepairCB(*ARI, ACS, NewArgOperands); | ||||||||
2227 | assert(ARI->getNumReplacementArgs() + NewFirstArgNum ==((void)0) | ||||||||
2228 | NewArgOperands.size() &&((void)0) | ||||||||
2229 | "ACS repair callback did not provide as many operand as new "((void)0) | ||||||||
2230 | "types were registered!")((void)0); | ||||||||
2231 | // TODO: Exose the attribute set to the ACS repair callback | ||||||||
2232 | NewArgOperandAttributes.append(ARI->ReplacementTypes.size(), | ||||||||
2233 | AttributeSet()); | ||||||||
2234 | } else { | ||||||||
2235 | NewArgOperands.push_back(ACS.getCallArgOperand(OldArgNum)); | ||||||||
2236 | NewArgOperandAttributes.push_back( | ||||||||
2237 | OldCallAttributeList.getParamAttributes(OldArgNum)); | ||||||||
2238 | } | ||||||||
2239 | } | ||||||||
2240 | |||||||||
2241 | assert(NewArgOperands.size() == NewArgOperandAttributes.size() &&((void)0) | ||||||||
2242 | "Mismatch # argument operands vs. # argument operand attributes!")((void)0); | ||||||||
2243 | assert(NewArgOperands.size() == NewFn->arg_size() &&((void)0) | ||||||||
2244 | "Mismatch # argument operands vs. # function arguments!")((void)0); | ||||||||
2245 | |||||||||
2246 | SmallVector<OperandBundleDef, 4> OperandBundleDefs; | ||||||||
2247 | OldCB->getOperandBundlesAsDefs(OperandBundleDefs); | ||||||||
2248 | |||||||||
2249 | // Create a new call or invoke instruction to replace the old one. | ||||||||
2250 | CallBase *NewCB; | ||||||||
2251 | if (InvokeInst *II = dyn_cast<InvokeInst>(OldCB)) { | ||||||||
2252 | NewCB = | ||||||||
2253 | InvokeInst::Create(NewFn, II->getNormalDest(), II->getUnwindDest(), | ||||||||
2254 | NewArgOperands, OperandBundleDefs, "", OldCB); | ||||||||
2255 | } else { | ||||||||
2256 | auto *NewCI = CallInst::Create(NewFn, NewArgOperands, OperandBundleDefs, | ||||||||
2257 | "", OldCB); | ||||||||
2258 | NewCI->setTailCallKind(cast<CallInst>(OldCB)->getTailCallKind()); | ||||||||
2259 | NewCB = NewCI; | ||||||||
2260 | } | ||||||||
2261 | |||||||||
2262 | // Copy over various properties and the new attributes. | ||||||||
2263 | NewCB->copyMetadata(*OldCB, {LLVMContext::MD_prof, LLVMContext::MD_dbg}); | ||||||||
2264 | NewCB->setCallingConv(OldCB->getCallingConv()); | ||||||||
2265 | NewCB->takeName(OldCB); | ||||||||
2266 | NewCB->setAttributes(AttributeList::get( | ||||||||
2267 | Ctx, OldCallAttributeList.getFnAttributes(), | ||||||||
2268 | OldCallAttributeList.getRetAttributes(), NewArgOperandAttributes)); | ||||||||
2269 | |||||||||
2270 | CallSitePairs.push_back({OldCB, NewCB}); | ||||||||
2271 | return true; | ||||||||
2272 | }; | ||||||||
2273 | |||||||||
2274 | // Use the CallSiteReplacementCreator to create replacement call sites. | ||||||||
2275 | bool AllCallSitesKnown; | ||||||||
2276 | bool Success = checkForAllCallSites(CallSiteReplacementCreator, *OldFn, | ||||||||
2277 | true, nullptr, AllCallSitesKnown); | ||||||||
2278 | (void)Success; | ||||||||
2279 | assert(Success && "Assumed call site replacement to succeed!")((void)0); | ||||||||
2280 | |||||||||
2281 | // Rewire the arguments. | ||||||||
2282 | Argument *OldFnArgIt = OldFn->arg_begin(); | ||||||||
2283 | Argument *NewFnArgIt = NewFn->arg_begin(); | ||||||||
2284 | for (unsigned OldArgNum = 0; OldArgNum < ARIs.size(); | ||||||||
2285 | ++OldArgNum, ++OldFnArgIt) { | ||||||||
2286 | if (const std::unique_ptr<ArgumentReplacementInfo> &ARI = | ||||||||
2287 | ARIs[OldArgNum]) { | ||||||||
2288 | if (ARI->CalleeRepairCB) | ||||||||
2289 | ARI->CalleeRepairCB(*ARI, *NewFn, NewFnArgIt); | ||||||||
2290 | NewFnArgIt += ARI->ReplacementTypes.size(); | ||||||||
2291 | } else { | ||||||||
2292 | NewFnArgIt->takeName(&*OldFnArgIt); | ||||||||
2293 | OldFnArgIt->replaceAllUsesWith(&*NewFnArgIt); | ||||||||
2294 | ++NewFnArgIt; | ||||||||
2295 | } | ||||||||
2296 | } | ||||||||
2297 | |||||||||
2298 | // Eliminate the instructions *after* we visited all of them. | ||||||||
2299 | for (auto &CallSitePair : CallSitePairs) { | ||||||||
2300 | CallBase &OldCB = *CallSitePair.first; | ||||||||
2301 | CallBase &NewCB = *CallSitePair.second; | ||||||||
2302 | assert(OldCB.getType() == NewCB.getType() &&((void)0) | ||||||||
2303 | "Cannot handle call sites with different types!")((void)0); | ||||||||
2304 | ModifiedFns.insert(OldCB.getFunction()); | ||||||||
2305 | CGUpdater.replaceCallSite(OldCB, NewCB); | ||||||||
2306 | OldCB.replaceAllUsesWith(&NewCB); | ||||||||
2307 | OldCB.eraseFromParent(); | ||||||||
2308 | } | ||||||||
2309 | |||||||||
2310 | // Replace the function in the call graph (if any). | ||||||||
2311 | CGUpdater.replaceFunctionWith(*OldFn, *NewFn); | ||||||||
2312 | |||||||||
2313 | // If the old function was modified and needed to be reanalyzed, the new one | ||||||||
2314 | // does now. | ||||||||
2315 | if (ModifiedFns.erase(OldFn)) | ||||||||
2316 | ModifiedFns.insert(NewFn); | ||||||||
2317 | |||||||||
2318 | Changed = ChangeStatus::CHANGED; | ||||||||
2319 | } | ||||||||
2320 | |||||||||
2321 | return Changed; | ||||||||
2322 | } | ||||||||
2323 | |||||||||
2324 | void InformationCache::initializeInformationCache(const Function &CF, | ||||||||
2325 | FunctionInfo &FI) { | ||||||||
2326 | // As we do not modify the function here we can remove the const | ||||||||
2327 | // withouth breaking implicit assumptions. At the end of the day, we could | ||||||||
2328 | // initialize the cache eagerly which would look the same to the users. | ||||||||
2329 | Function &F = const_cast<Function &>(CF); | ||||||||
2330 | |||||||||
2331 | // Walk all instructions to find interesting instructions that might be | ||||||||
2332 | // queried by abstract attributes during their initialization or update. | ||||||||
2333 | // This has to happen before we create attributes. | ||||||||
2334 | |||||||||
2335 | for (Instruction &I : instructions(&F)) { | ||||||||
2336 | bool IsInterestingOpcode = false; | ||||||||
2337 | |||||||||
2338 | // To allow easy access to all instructions in a function with a given | ||||||||
2339 | // opcode we store them in the InfoCache. As not all opcodes are interesting | ||||||||
2340 | // to concrete attributes we only cache the ones that are as identified in | ||||||||
2341 | // the following switch. | ||||||||
2342 | // Note: There are no concrete attributes now so this is initially empty. | ||||||||
2343 | switch (I.getOpcode()) { | ||||||||
2344 | default: | ||||||||
2345 | assert(!isa<CallBase>(&I) &&((void)0) | ||||||||
2346 | "New call base instruction type needs to be known in the "((void)0) | ||||||||
2347 | "Attributor.")((void)0); | ||||||||
2348 | break; | ||||||||
2349 | case Instruction::Call: | ||||||||
2350 | // Calls are interesting on their own, additionally: | ||||||||
2351 | // For `llvm.assume` calls we also fill the KnowledgeMap as we find them. | ||||||||
2352 | // For `must-tail` calls we remember the caller and callee. | ||||||||
2353 | if (auto *Assume = dyn_cast<AssumeInst>(&I)) { | ||||||||
2354 | fillMapFromAssume(*Assume, KnowledgeMap); | ||||||||
2355 | } else if (cast<CallInst>(I).isMustTailCall()) { | ||||||||
2356 | FI.ContainsMustTailCall = true; | ||||||||
2357 | if (const Function *Callee = cast<CallInst>(I).getCalledFunction()) | ||||||||
2358 | getFunctionInfo(*Callee).CalledViaMustTail = true; | ||||||||
2359 | } | ||||||||
2360 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; | ||||||||
2361 | case Instruction::CallBr: | ||||||||
2362 | case Instruction::Invoke: | ||||||||
2363 | case Instruction::CleanupRet: | ||||||||
2364 | case Instruction::CatchSwitch: | ||||||||
2365 | case Instruction::AtomicRMW: | ||||||||
2366 | case Instruction::AtomicCmpXchg: | ||||||||
2367 | case Instruction::Br: | ||||||||
2368 | case Instruction::Resume: | ||||||||
2369 | case Instruction::Ret: | ||||||||
2370 | case Instruction::Load: | ||||||||
2371 | // The alignment of a pointer is interesting for loads. | ||||||||
2372 | case Instruction::Store: | ||||||||
2373 | // The alignment of a pointer is interesting for stores. | ||||||||
2374 | case Instruction::Alloca: | ||||||||
2375 | case Instruction::AddrSpaceCast: | ||||||||
2376 | IsInterestingOpcode = true; | ||||||||
2377 | } | ||||||||
2378 | if (IsInterestingOpcode) { | ||||||||
2379 | auto *&Insts = FI.OpcodeInstMap[I.getOpcode()]; | ||||||||
2380 | if (!Insts) | ||||||||
2381 | Insts = new (Allocator) InstructionVectorTy(); | ||||||||
2382 | Insts->push_back(&I); | ||||||||
2383 | } | ||||||||
2384 | if (I.mayReadOrWriteMemory()) | ||||||||
2385 | FI.RWInsts.push_back(&I); | ||||||||
2386 | } | ||||||||
2387 | |||||||||
2388 | if (F.hasFnAttribute(Attribute::AlwaysInline) && | ||||||||
2389 | isInlineViable(F).isSuccess()) | ||||||||
2390 | InlineableFunctions.insert(&F); | ||||||||
2391 | } | ||||||||
2392 | |||||||||
2393 | AAResults *InformationCache::getAAResultsForFunction(const Function &F) { | ||||||||
2394 | return AG.getAnalysis<AAManager>(F); | ||||||||
2395 | } | ||||||||
2396 | |||||||||
2397 | InformationCache::FunctionInfo::~FunctionInfo() { | ||||||||
2398 | // The instruction vectors are allocated using a BumpPtrAllocator, we need to | ||||||||
2399 | // manually destroy them. | ||||||||
2400 | for (auto &It : OpcodeInstMap) | ||||||||
2401 | It.getSecond()->~InstructionVectorTy(); | ||||||||
2402 | } | ||||||||
2403 | |||||||||
2404 | void Attributor::recordDependence(const AbstractAttribute &FromAA, | ||||||||
2405 | const AbstractAttribute &ToAA, | ||||||||
2406 | DepClassTy DepClass) { | ||||||||
2407 | if (DepClass == DepClassTy::NONE) | ||||||||
2408 | return; | ||||||||
2409 | // If we are outside of an update, thus before the actual fixpoint iteration | ||||||||
2410 | // started (= when we create AAs), we do not track dependences because we will | ||||||||
2411 | // put all AAs into the initial worklist anyway. | ||||||||
2412 | if (DependenceStack.empty()) | ||||||||
2413 | return; | ||||||||
2414 | if (FromAA.getState().isAtFixpoint()) | ||||||||
2415 | return; | ||||||||
2416 | DependenceStack.back()->push_back({&FromAA, &ToAA, DepClass}); | ||||||||
2417 | } | ||||||||
2418 | |||||||||
2419 | void Attributor::rememberDependences() { | ||||||||
2420 | assert(!DependenceStack.empty() && "No dependences to remember!")((void)0); | ||||||||
2421 | |||||||||
2422 | for (DepInfo &DI : *DependenceStack.back()) { | ||||||||
2423 | assert((DI.DepClass == DepClassTy::REQUIRED ||((void)0) | ||||||||
2424 | DI.DepClass == DepClassTy::OPTIONAL) &&((void)0) | ||||||||
2425 | "Expected required or optional dependence (1 bit)!")((void)0); | ||||||||
2426 | auto &DepAAs = const_cast<AbstractAttribute &>(*DI.FromAA).Deps; | ||||||||
2427 | DepAAs.push_back(AbstractAttribute::DepTy( | ||||||||
2428 | const_cast<AbstractAttribute *>(DI.ToAA), unsigned(DI.DepClass))); | ||||||||
2429 | } | ||||||||
2430 | } | ||||||||
2431 | |||||||||
2432 | void Attributor::identifyDefaultAbstractAttributes(Function &F) { | ||||||||
2433 | if (!VisitedFunctions.insert(&F).second) | ||||||||
2434 | return; | ||||||||
2435 | if (F.isDeclaration()) | ||||||||
2436 | return; | ||||||||
2437 | |||||||||
2438 | // In non-module runs we need to look at the call sites of a function to | ||||||||
2439 | // determine if it is part of a must-tail call edge. This will influence what | ||||||||
2440 | // attributes we can derive. | ||||||||
2441 | InformationCache::FunctionInfo &FI = InfoCache.getFunctionInfo(F); | ||||||||
2442 | if (!isModulePass() && !FI.CalledViaMustTail) { | ||||||||
2443 | for (const Use &U : F.uses()) | ||||||||
2444 | if (const auto *CB = dyn_cast<CallBase>(U.getUser())) | ||||||||
2445 | if (CB->isCallee(&U) && CB->isMustTailCall()) | ||||||||
2446 | FI.CalledViaMustTail = true; | ||||||||
2447 | } | ||||||||
2448 | |||||||||
2449 | IRPosition FPos = IRPosition::function(F); | ||||||||
2450 | |||||||||
2451 | // Check for dead BasicBlocks in every function. | ||||||||
2452 | // We need dead instruction detection because we do not want to deal with | ||||||||
2453 | // broken IR in which SSA rules do not apply. | ||||||||
2454 | getOrCreateAAFor<AAIsDead>(FPos); | ||||||||
2455 | |||||||||
2456 | // Every function might be "will-return". | ||||||||
2457 | getOrCreateAAFor<AAWillReturn>(FPos); | ||||||||
2458 | |||||||||
2459 | // Every function might contain instructions that cause "undefined behavior". | ||||||||
2460 | getOrCreateAAFor<AAUndefinedBehavior>(FPos); | ||||||||
2461 | |||||||||
2462 | // Every function can be nounwind. | ||||||||
2463 | getOrCreateAAFor<AANoUnwind>(FPos); | ||||||||
2464 | |||||||||
2465 | // Every function might be marked "nosync" | ||||||||
2466 | getOrCreateAAFor<AANoSync>(FPos); | ||||||||
2467 | |||||||||
2468 | // Every function might be "no-free". | ||||||||
2469 | getOrCreateAAFor<AANoFree>(FPos); | ||||||||
2470 | |||||||||
2471 | // Every function might be "no-return". | ||||||||
2472 | getOrCreateAAFor<AANoReturn>(FPos); | ||||||||
2473 | |||||||||
2474 | // Every function might be "no-recurse". | ||||||||
2475 | getOrCreateAAFor<AANoRecurse>(FPos); | ||||||||
2476 | |||||||||
2477 | // Every function might be "readnone/readonly/writeonly/...". | ||||||||
2478 | getOrCreateAAFor<AAMemoryBehavior>(FPos); | ||||||||
2479 | |||||||||
2480 | // Every function can be "readnone/argmemonly/inaccessiblememonly/...". | ||||||||
2481 | getOrCreateAAFor<AAMemoryLocation>(FPos); | ||||||||
2482 | |||||||||
2483 | // Every function might be applicable for Heap-To-Stack conversion. | ||||||||
2484 | if (EnableHeapToStack) | ||||||||
2485 | getOrCreateAAFor<AAHeapToStack>(FPos); | ||||||||
2486 | |||||||||
2487 | // Return attributes are only appropriate if the return type is non void. | ||||||||
2488 | Type *ReturnType = F.getReturnType(); | ||||||||
2489 | if (!ReturnType->isVoidTy()) { | ||||||||
2490 | // Argument attribute "returned" --- Create only one per function even | ||||||||
2491 | // though it is an argument attribute. | ||||||||
2492 | getOrCreateAAFor<AAReturnedValues>(FPos); | ||||||||
2493 | |||||||||
2494 | IRPosition RetPos = IRPosition::returned(F); | ||||||||
2495 | |||||||||
2496 | // Every returned value might be dead. | ||||||||
2497 | getOrCreateAAFor<AAIsDead>(RetPos); | ||||||||
2498 | |||||||||
2499 | // Every function might be simplified. | ||||||||
2500 | getOrCreateAAFor<AAValueSimplify>(RetPos); | ||||||||
2501 | |||||||||
2502 | // Every returned value might be marked noundef. | ||||||||
2503 | getOrCreateAAFor<AANoUndef>(RetPos); | ||||||||
2504 | |||||||||
2505 | if (ReturnType->isPointerTy()) { | ||||||||
2506 | |||||||||
2507 | // Every function with pointer return type might be marked align. | ||||||||
2508 | getOrCreateAAFor<AAAlign>(RetPos); | ||||||||
2509 | |||||||||
2510 | // Every function with pointer return type might be marked nonnull. | ||||||||
2511 | getOrCreateAAFor<AANonNull>(RetPos); | ||||||||
2512 | |||||||||
2513 | // Every function with pointer return type might be marked noalias. | ||||||||
2514 | getOrCreateAAFor<AANoAlias>(RetPos); | ||||||||
2515 | |||||||||
2516 | // Every function with pointer return type might be marked | ||||||||
2517 | // dereferenceable. | ||||||||
2518 | getOrCreateAAFor<AADereferenceable>(RetPos); | ||||||||
2519 | } | ||||||||
2520 | } | ||||||||
2521 | |||||||||
2522 | for (Argument &Arg : F.args()) { | ||||||||
2523 | IRPosition ArgPos = IRPosition::argument(Arg); | ||||||||
2524 | |||||||||
2525 | // Every argument might be simplified. We have to go through the Attributor | ||||||||
2526 | // interface though as outside AAs can register custom simplification | ||||||||
2527 | // callbacks. | ||||||||
2528 | bool UsedAssumedInformation = false; | ||||||||
2529 | getAssumedSimplified(ArgPos, /* AA */ nullptr, UsedAssumedInformation); | ||||||||
2530 | |||||||||
2531 | // Every argument might be dead. | ||||||||
2532 | getOrCreateAAFor<AAIsDead>(ArgPos); | ||||||||
2533 | |||||||||
2534 | // Every argument might be marked noundef. | ||||||||
2535 | getOrCreateAAFor<AANoUndef>(ArgPos); | ||||||||
2536 | |||||||||
2537 | if (Arg.getType()->isPointerTy()) { | ||||||||
2538 | // Every argument with pointer type might be marked nonnull. | ||||||||
2539 | getOrCreateAAFor<AANonNull>(ArgPos); | ||||||||
2540 | |||||||||
2541 | // Every argument with pointer type might be marked noalias. | ||||||||
2542 | getOrCreateAAFor<AANoAlias>(ArgPos); | ||||||||
2543 | |||||||||
2544 | // Every argument with pointer type might be marked dereferenceable. | ||||||||
2545 | getOrCreateAAFor<AADereferenceable>(ArgPos); | ||||||||
2546 | |||||||||
2547 | // Every argument with pointer type might be marked align. | ||||||||
2548 | getOrCreateAAFor<AAAlign>(ArgPos); | ||||||||
2549 | |||||||||
2550 | // Every argument with pointer type might be marked nocapture. | ||||||||
2551 | getOrCreateAAFor<AANoCapture>(ArgPos); | ||||||||
2552 | |||||||||
2553 | // Every argument with pointer type might be marked | ||||||||
2554 | // "readnone/readonly/writeonly/..." | ||||||||
2555 | getOrCreateAAFor<AAMemoryBehavior>(ArgPos); | ||||||||
2556 | |||||||||
2557 | // Every argument with pointer type might be marked nofree. | ||||||||
2558 | getOrCreateAAFor<AANoFree>(ArgPos); | ||||||||
2559 | |||||||||
2560 | // Every argument with pointer type might be privatizable (or promotable) | ||||||||
2561 | getOrCreateAAFor<AAPrivatizablePtr>(ArgPos); | ||||||||
2562 | } | ||||||||
2563 | } | ||||||||
2564 | |||||||||
2565 | auto CallSitePred = [&](Instruction &I) -> bool { | ||||||||
2566 | auto &CB = cast<CallBase>(I); | ||||||||
2567 | IRPosition CBRetPos = IRPosition::callsite_returned(CB); | ||||||||
2568 | |||||||||
2569 | // Call sites might be dead if they do not have side effects and no live | ||||||||
2570 | // users. The return value might be dead if there are no live users. | ||||||||
2571 | getOrCreateAAFor<AAIsDead>(CBRetPos); | ||||||||
2572 | |||||||||
2573 | Function *Callee = CB.getCalledFunction(); | ||||||||
2574 | // TODO: Even if the callee is not known now we might be able to simplify | ||||||||
2575 | // the call/callee. | ||||||||
2576 | if (!Callee) | ||||||||
2577 | return true; | ||||||||
2578 | |||||||||
2579 | // Skip declarations except if annotations on their call sites were | ||||||||
2580 | // explicitly requested. | ||||||||
2581 | if (!AnnotateDeclarationCallSites && Callee->isDeclaration() && | ||||||||
2582 | !Callee->hasMetadata(LLVMContext::MD_callback)) | ||||||||
2583 | return true; | ||||||||
2584 | |||||||||
2585 | if (!Callee->getReturnType()->isVoidTy() && !CB.use_empty()) { | ||||||||
2586 | |||||||||
2587 | IRPosition CBRetPos = IRPosition::callsite_returned(CB); | ||||||||
2588 | getOrCreateAAFor<AAValueSimplify>(CBRetPos); | ||||||||
2589 | } | ||||||||
2590 | |||||||||
2591 | for (int I = 0, E = CB.getNumArgOperands(); I < E; ++I) { | ||||||||
2592 | |||||||||
2593 | IRPosition CBArgPos = IRPosition::callsite_argument(CB, I); | ||||||||
2594 | |||||||||
2595 | // Every call site argument might be dead. | ||||||||
2596 | getOrCreateAAFor<AAIsDead>(CBArgPos); | ||||||||
2597 | |||||||||
2598 | // Call site argument might be simplified. We have to go through the | ||||||||
2599 | // Attributor interface though as outside AAs can register custom | ||||||||
2600 | // simplification callbacks. | ||||||||
2601 | bool UsedAssumedInformation = false; | ||||||||
2602 | getAssumedSimplified(CBArgPos, /* AA */ nullptr, UsedAssumedInformation); | ||||||||
2603 | |||||||||
2604 | // Every call site argument might be marked "noundef". | ||||||||
2605 | getOrCreateAAFor<AANoUndef>(CBArgPos); | ||||||||
2606 | |||||||||
2607 | if (!CB.getArgOperand(I)->getType()->isPointerTy()) | ||||||||
2608 | continue; | ||||||||
2609 | |||||||||
2610 | // Call site argument attribute "non-null". | ||||||||
2611 | getOrCreateAAFor<AANonNull>(CBArgPos); | ||||||||
2612 | |||||||||
2613 | // Call site argument attribute "nocapture". | ||||||||
2614 | getOrCreateAAFor<AANoCapture>(CBArgPos); | ||||||||
2615 | |||||||||
2616 | // Call site argument attribute "no-alias". | ||||||||
2617 | getOrCreateAAFor<AANoAlias>(CBArgPos); | ||||||||
2618 | |||||||||
2619 | // Call site argument attribute "dereferenceable". | ||||||||
2620 | getOrCreateAAFor<AADereferenceable>(CBArgPos); | ||||||||
2621 | |||||||||
2622 | // Call site argument attribute "align". | ||||||||
2623 | getOrCreateAAFor<AAAlign>(CBArgPos); | ||||||||
2624 | |||||||||
2625 | // Call site argument attribute | ||||||||
2626 | // "readnone/readonly/writeonly/..." | ||||||||
2627 | getOrCreateAAFor<AAMemoryBehavior>(CBArgPos); | ||||||||
2628 | |||||||||
2629 | // Call site argument attribute "nofree". | ||||||||
2630 | getOrCreateAAFor<AANoFree>(CBArgPos); | ||||||||
2631 | } | ||||||||
2632 | return true; | ||||||||
2633 | }; | ||||||||
2634 | |||||||||
2635 | auto &OpcodeInstMap = InfoCache.getOpcodeInstMapForFunction(F); | ||||||||
2636 | bool Success; | ||||||||
2637 | bool UsedAssumedInformation = false; | ||||||||
2638 | Success = checkForAllInstructionsImpl( | ||||||||
2639 | nullptr, OpcodeInstMap, CallSitePred, nullptr, nullptr, | ||||||||
2640 | {(unsigned)Instruction::Invoke, (unsigned)Instruction::CallBr, | ||||||||
2641 | (unsigned)Instruction::Call}, | ||||||||
2642 | UsedAssumedInformation); | ||||||||
2643 | (void)Success; | ||||||||
2644 | assert(Success && "Expected the check call to be successful!")((void)0); | ||||||||
2645 | |||||||||
2646 | auto LoadStorePred = [&](Instruction &I) -> bool { | ||||||||
2647 | if (isa<LoadInst>(I)) { | ||||||||
2648 | getOrCreateAAFor<AAAlign>( | ||||||||
2649 | IRPosition::value(*cast<LoadInst>(I).getPointerOperand())); | ||||||||
2650 | if (SimplifyAllLoads) | ||||||||
2651 | getOrCreateAAFor<AAValueSimplify>(IRPosition::value(I)); | ||||||||
2652 | } else | ||||||||
2653 | getOrCreateAAFor<AAAlign>( | ||||||||
2654 | IRPosition::value(*cast<StoreInst>(I).getPointerOperand())); | ||||||||
2655 | return true; | ||||||||
2656 | }; | ||||||||
2657 | Success = checkForAllInstructionsImpl( | ||||||||
2658 | nullptr, OpcodeInstMap, LoadStorePred, nullptr, nullptr, | ||||||||
2659 | {(unsigned)Instruction::Load, (unsigned)Instruction::Store}, | ||||||||
2660 | UsedAssumedInformation); | ||||||||
2661 | (void)Success; | ||||||||
2662 | assert(Success && "Expected the check call to be successful!")((void)0); | ||||||||
2663 | } | ||||||||
2664 | |||||||||
2665 | /// Helpers to ease debugging through output streams and print calls. | ||||||||
2666 | /// | ||||||||
2667 | ///{ | ||||||||
2668 | raw_ostream &llvm::operator<<(raw_ostream &OS, ChangeStatus S) { | ||||||||
2669 | return OS << (S == ChangeStatus::CHANGED ? "changed" : "unchanged"); | ||||||||
2670 | } | ||||||||
2671 | |||||||||
2672 | raw_ostream &llvm::operator<<(raw_ostream &OS, IRPosition::Kind AP) { | ||||||||
2673 | switch (AP) { | ||||||||
2674 | case IRPosition::IRP_INVALID: | ||||||||
2675 | return OS << "inv"; | ||||||||
2676 | case IRPosition::IRP_FLOAT: | ||||||||
2677 | return OS << "flt"; | ||||||||
2678 | case IRPosition::IRP_RETURNED: | ||||||||
2679 | return OS << "fn_ret"; | ||||||||
2680 | case IRPosition::IRP_CALL_SITE_RETURNED: | ||||||||
2681 | return OS << "cs_ret"; | ||||||||
2682 | case IRPosition::IRP_FUNCTION: | ||||||||
2683 | return OS << "fn"; | ||||||||
2684 | case IRPosition::IRP_CALL_SITE: | ||||||||
2685 | return OS << "cs"; | ||||||||
2686 | case IRPosition::IRP_ARGUMENT: | ||||||||
2687 | return OS << "arg"; | ||||||||
2688 | case IRPosition::IRP_CALL_SITE_ARGUMENT: | ||||||||
2689 | return OS << "cs_arg"; | ||||||||
2690 | } | ||||||||
2691 | llvm_unreachable("Unknown attribute position!")__builtin_unreachable(); | ||||||||
2692 | } | ||||||||
2693 | |||||||||
2694 | raw_ostream &llvm::operator<<(raw_ostream &OS, const IRPosition &Pos) { | ||||||||
2695 | const Value &AV = Pos.getAssociatedValue(); | ||||||||
2696 | OS << "{" << Pos.getPositionKind() << ":" << AV.getName() << " [" | ||||||||
2697 | << Pos.getAnchorValue().getName() << "@" << Pos.getCallSiteArgNo() << "]"; | ||||||||
2698 | |||||||||
2699 | if (Pos.hasCallBaseContext()) | ||||||||
2700 | OS << "[cb_context:" << *Pos.getCallBaseContext() << "]"; | ||||||||
2701 | return OS << "}"; | ||||||||
2702 | } | ||||||||
2703 | |||||||||
2704 | raw_ostream &llvm::operator<<(raw_ostream &OS, const IntegerRangeState &S) { | ||||||||
2705 | OS << "range-state(" << S.getBitWidth() << ")<"; | ||||||||
2706 | S.getKnown().print(OS); | ||||||||
2707 | OS << " / "; | ||||||||
2708 | S.getAssumed().print(OS); | ||||||||
2709 | OS << ">"; | ||||||||
2710 | |||||||||
2711 | return OS << static_cast<const AbstractState &>(S); | ||||||||
2712 | } | ||||||||
2713 | |||||||||
2714 | raw_ostream &llvm::operator<<(raw_ostream &OS, const AbstractState &S) { | ||||||||
2715 | return OS << (!S.isValidState() ? "top" : (S.isAtFixpoint() ? "fix" : "")); | ||||||||
2716 | } | ||||||||
2717 | |||||||||
2718 | raw_ostream &llvm::operator<<(raw_ostream &OS, const AbstractAttribute &AA) { | ||||||||
2719 | AA.print(OS); | ||||||||
2720 | return OS; | ||||||||
2721 | } | ||||||||
2722 | |||||||||
2723 | raw_ostream &llvm::operator<<(raw_ostream &OS, | ||||||||
2724 | const PotentialConstantIntValuesState &S) { | ||||||||
2725 | OS << "set-state(< {"; | ||||||||
2726 | if (!S.isValidState()) | ||||||||
2727 | OS << "full-set"; | ||||||||
2728 | else { | ||||||||
2729 | for (auto &it : S.getAssumedSet()) | ||||||||
2730 | OS << it << ", "; | ||||||||
2731 | if (S.undefIsContained()) | ||||||||
2732 | OS << "undef "; | ||||||||
2733 | } | ||||||||
2734 | OS << "} >)"; | ||||||||
2735 | |||||||||
2736 | return OS; | ||||||||
2737 | } | ||||||||
2738 | |||||||||
2739 | void AbstractAttribute::print(raw_ostream &OS) const { | ||||||||
2740 | OS << "["; | ||||||||
2741 | OS << getName(); | ||||||||
2742 | OS << "] for CtxI "; | ||||||||
2743 | |||||||||
2744 | if (auto *I = getCtxI()) { | ||||||||
2745 | OS << "'"; | ||||||||
2746 | I->print(OS); | ||||||||
2747 | OS << "'"; | ||||||||
2748 | } else | ||||||||
2749 | OS << "<<null inst>>"; | ||||||||
2750 | |||||||||
2751 | OS << " at position " << getIRPosition() << " with state " << getAsStr() | ||||||||
2752 | << '\n'; | ||||||||
2753 | } | ||||||||
2754 | |||||||||
2755 | void AbstractAttribute::printWithDeps(raw_ostream &OS) const { | ||||||||
2756 | print(OS); | ||||||||
2757 | |||||||||
2758 | for (const auto &DepAA : Deps) { | ||||||||
2759 | auto *AA = DepAA.getPointer(); | ||||||||
2760 | OS << " updates "; | ||||||||
2761 | AA->print(OS); | ||||||||
2762 | } | ||||||||
2763 | |||||||||
2764 | OS << '\n'; | ||||||||
2765 | } | ||||||||
2766 | |||||||||
2767 | raw_ostream &llvm::operator<<(raw_ostream &OS, | ||||||||
2768 | const AAPointerInfo::Access &Acc) { | ||||||||
2769 | OS << " [" << Acc.getKind() << "] " << *Acc.getRemoteInst(); | ||||||||
2770 | if (Acc.getLocalInst() != Acc.getRemoteInst()) | ||||||||
2771 | OS << " via " << *Acc.getLocalInst(); | ||||||||
2772 | if (Acc.getContent().hasValue()) | ||||||||
2773 | OS << " [" << *Acc.getContent() << "]"; | ||||||||
2774 | return OS; | ||||||||
2775 | } | ||||||||
2776 | ///} | ||||||||
2777 | |||||||||
2778 | /// ---------------------------------------------------------------------------- | ||||||||
2779 | /// Pass (Manager) Boilerplate | ||||||||
2780 | /// ---------------------------------------------------------------------------- | ||||||||
2781 | |||||||||
2782 | static bool runAttributorOnFunctions(InformationCache &InfoCache, | ||||||||
2783 | SetVector<Function *> &Functions, | ||||||||
2784 | AnalysisGetter &AG, | ||||||||
2785 | CallGraphUpdater &CGUpdater, | ||||||||
2786 | bool DeleteFns) { | ||||||||
2787 | if (Functions.empty()) | ||||||||
2788 | return false; | ||||||||
2789 | |||||||||
2790 | LLVM_DEBUG({do { } while (false) | ||||||||
2791 | dbgs() << "[Attributor] Run on module with " << Functions.size()do { } while (false) | ||||||||
2792 | << " functions:\n";do { } while (false) | ||||||||
2793 | for (Function *Fn : Functions)do { } while (false) | ||||||||
2794 | dbgs() << " - " << Fn->getName() << "\n";do { } while (false) | ||||||||
2795 | })do { } while (false); | ||||||||
2796 | |||||||||
2797 | // Create an Attributor and initially empty information cache that is filled | ||||||||
2798 | // while we identify default attribute opportunities. | ||||||||
2799 | Attributor A(Functions, InfoCache, CGUpdater, /* Allowed */ nullptr, | ||||||||
2800 | DeleteFns); | ||||||||
2801 | |||||||||
2802 | // Create shallow wrappers for all functions that are not IPO amendable | ||||||||
2803 | if (AllowShallowWrappers) | ||||||||
2804 | for (Function *F : Functions) | ||||||||
2805 | if (!A.isFunctionIPOAmendable(*F)) | ||||||||
2806 | Attributor::createShallowWrapper(*F); | ||||||||
2807 | |||||||||
2808 | // Internalize non-exact functions | ||||||||
2809 | // TODO: for now we eagerly internalize functions without calculating the | ||||||||
2810 | // cost, we need a cost interface to determine whether internalizing | ||||||||
2811 | // a function is "benefitial" | ||||||||
2812 | if (AllowDeepWrapper) { | ||||||||
2813 | unsigned FunSize = Functions.size(); | ||||||||
2814 | for (unsigned u = 0; u < FunSize; u++) { | ||||||||
2815 | Function *F = Functions[u]; | ||||||||
2816 | if (!F->isDeclaration() && !F->isDefinitionExact() && F->getNumUses() && | ||||||||
2817 | !GlobalValue::isInterposableLinkage(F->getLinkage())) { | ||||||||
2818 | Function *NewF = Attributor::internalizeFunction(*F); | ||||||||
2819 | assert(NewF && "Could not internalize function.")((void)0); | ||||||||
2820 | Functions.insert(NewF); | ||||||||
2821 | |||||||||
2822 | // Update call graph | ||||||||
2823 | CGUpdater.replaceFunctionWith(*F, *NewF); | ||||||||
2824 | for (const Use &U : NewF->uses()) | ||||||||
2825 | if (CallBase *CB = dyn_cast<CallBase>(U.getUser())) { | ||||||||
2826 | auto *CallerF = CB->getCaller(); | ||||||||
2827 | CGUpdater.reanalyzeFunction(*CallerF); | ||||||||
2828 | } | ||||||||
2829 | } | ||||||||
2830 | } | ||||||||
2831 | } | ||||||||
2832 | |||||||||
2833 | for (Function *F : Functions) { | ||||||||
2834 | if (F->hasExactDefinition()) | ||||||||
2835 | NumFnWithExactDefinition++; | ||||||||
2836 | else | ||||||||
2837 | NumFnWithoutExactDefinition++; | ||||||||
2838 | |||||||||
2839 | // We look at internal functions only on-demand but if any use is not a | ||||||||
2840 | // direct call or outside the current set of analyzed functions, we have | ||||||||
2841 | // to do it eagerly. | ||||||||
2842 | if (F->hasLocalLinkage()) { | ||||||||
2843 | if (llvm::all_of(F->uses(), [&Functions](const Use &U) { | ||||||||
2844 | const auto *CB = dyn_cast<CallBase>(U.getUser()); | ||||||||
2845 | return CB && CB->isCallee(&U) && | ||||||||
2846 | Functions.count(const_cast<Function *>(CB->getCaller())); | ||||||||
2847 | })) | ||||||||
2848 | continue; | ||||||||
2849 | } | ||||||||
2850 | |||||||||
2851 | // Populate the Attributor with abstract attribute opportunities in the | ||||||||
2852 | // function and the information cache with IR information. | ||||||||
2853 | A.identifyDefaultAbstractAttributes(*F); | ||||||||
2854 | } | ||||||||
2855 | |||||||||
2856 | ChangeStatus Changed = A.run(); | ||||||||
2857 | |||||||||
2858 | LLVM_DEBUG(dbgs() << "[Attributor] Done with " << Functions.size()do { } while (false) | ||||||||
2859 | << " functions, result: " << Changed << ".\n")do { } while (false); | ||||||||
2860 | return Changed == ChangeStatus::CHANGED; | ||||||||
2861 | } | ||||||||
2862 | |||||||||
2863 | void AADepGraph::viewGraph() { llvm::ViewGraph(this, "Dependency Graph"); } | ||||||||
2864 | |||||||||
2865 | void AADepGraph::dumpGraph() { | ||||||||
2866 | static std::atomic<int> CallTimes; | ||||||||
2867 | std::string Prefix; | ||||||||
2868 | |||||||||
2869 | if (!DepGraphDotFileNamePrefix.empty()) | ||||||||
2870 | Prefix = DepGraphDotFileNamePrefix; | ||||||||
2871 | else | ||||||||
2872 | Prefix = "dep_graph"; | ||||||||
2873 | std::string Filename = | ||||||||
2874 | Prefix + "_" + std::to_string(CallTimes.load()) + ".dot"; | ||||||||
2875 | |||||||||
2876 | outs() << "Dependency graph dump to " << Filename << ".\n"; | ||||||||
2877 | |||||||||
2878 | std::error_code EC; | ||||||||
2879 | |||||||||
2880 | raw_fd_ostream File(Filename, EC, sys::fs::OF_TextWithCRLF); | ||||||||
2881 | if (!EC) | ||||||||
2882 | llvm::WriteGraph(File, this); | ||||||||
2883 | |||||||||
2884 | CallTimes++; | ||||||||
2885 | } | ||||||||
2886 | |||||||||
2887 | void AADepGraph::print() { | ||||||||
2888 | for (auto DepAA : SyntheticRoot.Deps) | ||||||||
2889 | cast<AbstractAttribute>(DepAA.getPointer())->printWithDeps(outs()); | ||||||||
2890 | } | ||||||||
2891 | |||||||||
2892 | PreservedAnalyses AttributorPass::run(Module &M, ModuleAnalysisManager &AM) { | ||||||||
2893 | FunctionAnalysisManager &FAM = | ||||||||
2894 | AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager(); | ||||||||
2895 | AnalysisGetter AG(FAM); | ||||||||
2896 | |||||||||
2897 | SetVector<Function *> Functions; | ||||||||
2898 | for (Function &F : M) | ||||||||
2899 | Functions.insert(&F); | ||||||||
2900 | |||||||||
2901 | CallGraphUpdater CGUpdater; | ||||||||
2902 | BumpPtrAllocator Allocator; | ||||||||
2903 | InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ nullptr); | ||||||||
2904 | if (runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater, | ||||||||
2905 | /* DeleteFns */ true)) { | ||||||||
2906 | // FIXME: Think about passes we will preserve and add them here. | ||||||||
2907 | return PreservedAnalyses::none(); | ||||||||
2908 | } | ||||||||
2909 | return PreservedAnalyses::all(); | ||||||||
2910 | } | ||||||||
2911 | |||||||||
2912 | PreservedAnalyses AttributorCGSCCPass::run(LazyCallGraph::SCC &C, | ||||||||
2913 | CGSCCAnalysisManager &AM, | ||||||||
2914 | LazyCallGraph &CG, | ||||||||
2915 | CGSCCUpdateResult &UR) { | ||||||||
2916 | FunctionAnalysisManager &FAM = | ||||||||
2917 | AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, CG).getManager(); | ||||||||
2918 | AnalysisGetter AG(FAM); | ||||||||
2919 | |||||||||
2920 | SetVector<Function *> Functions; | ||||||||
2921 | for (LazyCallGraph::Node &N : C) | ||||||||
2922 | Functions.insert(&N.getFunction()); | ||||||||
2923 | |||||||||
2924 | if (Functions.empty()) | ||||||||
2925 | return PreservedAnalyses::all(); | ||||||||
2926 | |||||||||
2927 | Module &M = *Functions.back()->getParent(); | ||||||||
2928 | CallGraphUpdater CGUpdater; | ||||||||
2929 | CGUpdater.initialize(CG, C, AM, UR); | ||||||||
2930 | BumpPtrAllocator Allocator; | ||||||||
2931 | InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ &Functions); | ||||||||
2932 | if (runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater, | ||||||||
2933 | /* DeleteFns */ false)) { | ||||||||
2934 | // FIXME: Think about passes we will preserve and add them here. | ||||||||
2935 | PreservedAnalyses PA; | ||||||||
2936 | PA.preserve<FunctionAnalysisManagerCGSCCProxy>(); | ||||||||
2937 | return PA; | ||||||||
2938 | } | ||||||||
2939 | return PreservedAnalyses::all(); | ||||||||
2940 | } | ||||||||
2941 | |||||||||
2942 | namespace llvm { | ||||||||
2943 | |||||||||
2944 | template <> struct GraphTraits<AADepGraphNode *> { | ||||||||
2945 | using NodeRef = AADepGraphNode *; | ||||||||
2946 | using DepTy = PointerIntPair<AADepGraphNode *, 1>; | ||||||||
2947 | using EdgeRef = PointerIntPair<AADepGraphNode *, 1>; | ||||||||
2948 | |||||||||
2949 | static NodeRef getEntryNode(AADepGraphNode *DGN) { return DGN; } | ||||||||
2950 | static NodeRef DepGetVal(DepTy &DT) { return DT.getPointer(); } | ||||||||
2951 | |||||||||
2952 | using ChildIteratorType = | ||||||||
2953 | mapped_iterator<TinyPtrVector<DepTy>::iterator, decltype(&DepGetVal)>; | ||||||||
2954 | using ChildEdgeIteratorType = TinyPtrVector<DepTy>::iterator; | ||||||||
2955 | |||||||||
2956 | static ChildIteratorType child_begin(NodeRef N) { return N->child_begin(); } | ||||||||
2957 | |||||||||
2958 | static ChildIteratorType child_end(NodeRef N) { return N->child_end(); } | ||||||||
2959 | }; | ||||||||
2960 | |||||||||
2961 | template <> | ||||||||
2962 | struct GraphTraits<AADepGraph *> : public GraphTraits<AADepGraphNode *> { | ||||||||
2963 | static NodeRef getEntryNode(AADepGraph *DG) { return DG->GetEntryNode(); } | ||||||||
2964 | |||||||||
2965 | using nodes_iterator = | ||||||||
2966 | mapped_iterator<TinyPtrVector<DepTy>::iterator, decltype(&DepGetVal)>; | ||||||||
2967 | |||||||||
2968 | static nodes_iterator nodes_begin(AADepGraph *DG) { return DG->begin(); } | ||||||||
2969 | |||||||||
2970 | static nodes_iterator nodes_end(AADepGraph *DG) { return DG->end(); } | ||||||||
2971 | }; | ||||||||
2972 | |||||||||
2973 | template <> struct DOTGraphTraits<AADepGraph *> : public DefaultDOTGraphTraits { | ||||||||
2974 | DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {} | ||||||||
2975 | |||||||||
2976 | static std::string getNodeLabel(const AADepGraphNode *Node, | ||||||||
2977 | const AADepGraph *DG) { | ||||||||
2978 | std::string AAString; | ||||||||
2979 | raw_string_ostream O(AAString); | ||||||||
2980 | Node->print(O); | ||||||||
2981 | return AAString; | ||||||||
2982 | } | ||||||||
2983 | }; | ||||||||
2984 | |||||||||
2985 | } // end namespace llvm | ||||||||
2986 | |||||||||
2987 | namespace { | ||||||||
2988 | |||||||||
2989 | struct AttributorLegacyPass : public ModulePass { | ||||||||
2990 | static char ID; | ||||||||
2991 | |||||||||
2992 | AttributorLegacyPass() : ModulePass(ID) { | ||||||||
2993 | initializeAttributorLegacyPassPass(*PassRegistry::getPassRegistry()); | ||||||||
2994 | } | ||||||||
2995 | |||||||||
2996 | bool runOnModule(Module &M) override { | ||||||||
2997 | if (skipModule(M)) | ||||||||
2998 | return false; | ||||||||
2999 | |||||||||
3000 | AnalysisGetter AG; | ||||||||
3001 | SetVector<Function *> Functions; | ||||||||
3002 | for (Function &F : M) | ||||||||
3003 | Functions.insert(&F); | ||||||||
3004 | |||||||||
3005 | CallGraphUpdater CGUpdater; | ||||||||
3006 | BumpPtrAllocator Allocator; | ||||||||
3007 | InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ nullptr); | ||||||||
3008 | return runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater, | ||||||||
3009 | /* DeleteFns*/ true); | ||||||||
3010 | } | ||||||||
3011 | |||||||||
3012 | void getAnalysisUsage(AnalysisUsage &AU) const override { | ||||||||
3013 | // FIXME: Think about passes we will preserve and add them here. | ||||||||
3014 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | ||||||||
3015 | } | ||||||||
3016 | }; | ||||||||
3017 | |||||||||
3018 | struct AttributorCGSCCLegacyPass : public CallGraphSCCPass { | ||||||||
3019 | static char ID; | ||||||||
3020 | |||||||||
3021 | AttributorCGSCCLegacyPass() : CallGraphSCCPass(ID) { | ||||||||
3022 | initializeAttributorCGSCCLegacyPassPass(*PassRegistry::getPassRegistry()); | ||||||||
3023 | } | ||||||||
3024 | |||||||||
3025 | bool runOnSCC(CallGraphSCC &SCC) override { | ||||||||
3026 | if (skipSCC(SCC)) | ||||||||
3027 | return false; | ||||||||
3028 | |||||||||
3029 | SetVector<Function *> Functions; | ||||||||
3030 | for (CallGraphNode *CGN : SCC) | ||||||||
3031 | if (Function *Fn = CGN->getFunction()) | ||||||||
3032 | if (!Fn->isDeclaration()) | ||||||||
3033 | Functions.insert(Fn); | ||||||||
3034 | |||||||||
3035 | if (Functions.empty()) | ||||||||
3036 | return false; | ||||||||
3037 | |||||||||
3038 | AnalysisGetter AG; | ||||||||
3039 | CallGraph &CG = const_cast<CallGraph &>(SCC.getCallGraph()); | ||||||||
3040 | CallGraphUpdater CGUpdater; | ||||||||
3041 | CGUpdater.initialize(CG, SCC); | ||||||||
3042 | Module &M = *Functions.back()->getParent(); | ||||||||
3043 | BumpPtrAllocator Allocator; | ||||||||
3044 | InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ &Functions); | ||||||||
3045 | return runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater, | ||||||||
3046 | /* DeleteFns */ false); | ||||||||
3047 | } | ||||||||
3048 | |||||||||
3049 | void getAnalysisUsage(AnalysisUsage &AU) const override { | ||||||||
3050 | // FIXME: Think about passes we will preserve and add them here. | ||||||||
3051 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | ||||||||
3052 | CallGraphSCCPass::getAnalysisUsage(AU); | ||||||||
3053 | } | ||||||||
3054 | }; | ||||||||
3055 | |||||||||
3056 | } // end anonymous namespace | ||||||||
3057 | |||||||||
3058 | Pass *llvm::createAttributorLegacyPass() { return new AttributorLegacyPass(); } | ||||||||
3059 | Pass *llvm::createAttributorCGSCCLegacyPass() { | ||||||||
3060 | return new AttributorCGSCCLegacyPass(); | ||||||||
3061 | } | ||||||||
3062 | |||||||||
3063 | char AttributorLegacyPass::ID = 0; | ||||||||
3064 | char AttributorCGSCCLegacyPass::ID = 0; | ||||||||
3065 | |||||||||
3066 | INITIALIZE_PASS_BEGIN(AttributorLegacyPass, "attributor",static void *initializeAttributorLegacyPassPassOnce(PassRegistry &Registry) { | ||||||||
3067 | "Deduce and propagate attributes", false, false)static void *initializeAttributorLegacyPassPassOnce(PassRegistry &Registry) { | ||||||||
3068 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry); | ||||||||
3069 | INITIALIZE_PASS_END(AttributorLegacyPass, "attributor",PassInfo *PI = new PassInfo( "Deduce and propagate attributes" , "attributor", &AttributorLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<AttributorLegacyPass>), false, false); Registry.registerPass(*PI, true); return PI; } static llvm:: once_flag InitializeAttributorLegacyPassPassFlag; void llvm:: initializeAttributorLegacyPassPass(PassRegistry &Registry ) { llvm::call_once(InitializeAttributorLegacyPassPassFlag, initializeAttributorLegacyPassPassOnce , std::ref(Registry)); } | ||||||||
3070 | "Deduce and propagate attributes", false, false)PassInfo *PI = new PassInfo( "Deduce and propagate attributes" , "attributor", &AttributorLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<AttributorLegacyPass>), false, false); Registry.registerPass(*PI, true); return PI; } static llvm:: once_flag InitializeAttributorLegacyPassPassFlag; void llvm:: initializeAttributorLegacyPassPass(PassRegistry &Registry ) { llvm::call_once(InitializeAttributorLegacyPassPassFlag, initializeAttributorLegacyPassPassOnce , std::ref(Registry)); } | ||||||||
3071 | INITIALIZE_PASS_BEGIN(AttributorCGSCCLegacyPass, "attributor-cgscc",static void *initializeAttributorCGSCCLegacyPassPassOnce(PassRegistry &Registry) { | ||||||||
3072 | "Deduce and propagate attributes (CGSCC pass)", false,static void *initializeAttributorCGSCCLegacyPassPassOnce(PassRegistry &Registry) { | ||||||||
3073 | false)static void *initializeAttributorCGSCCLegacyPassPassOnce(PassRegistry &Registry) { | ||||||||
3074 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry); | ||||||||
3075 | INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)initializeCallGraphWrapperPassPass(Registry); | ||||||||
3076 | INITIALIZE_PASS_END(AttributorCGSCCLegacyPass, "attributor-cgscc",PassInfo *PI = new PassInfo( "Deduce and propagate attributes (CGSCC pass)" , "attributor-cgscc", &AttributorCGSCCLegacyPass::ID, PassInfo ::NormalCtor_t(callDefaultCtor<AttributorCGSCCLegacyPass> ), false, false); Registry.registerPass(*PI, true); return PI ; } static llvm::once_flag InitializeAttributorCGSCCLegacyPassPassFlag ; void llvm::initializeAttributorCGSCCLegacyPassPass(PassRegistry &Registry) { llvm::call_once(InitializeAttributorCGSCCLegacyPassPassFlag , initializeAttributorCGSCCLegacyPassPassOnce, std::ref(Registry )); } | ||||||||
3077 | "Deduce and propagate attributes (CGSCC pass)", false,PassInfo *PI = new PassInfo( "Deduce and propagate attributes (CGSCC pass)" , "attributor-cgscc", &AttributorCGSCCLegacyPass::ID, PassInfo ::NormalCtor_t(callDefaultCtor<AttributorCGSCCLegacyPass> ), false, false); Registry.registerPass(*PI, true); return PI ; } static llvm::once_flag InitializeAttributorCGSCCLegacyPassPassFlag ; void llvm::initializeAttributorCGSCCLegacyPassPass(PassRegistry &Registry) { llvm::call_once(InitializeAttributorCGSCCLegacyPassPassFlag , initializeAttributorCGSCCLegacyPassPassOnce, std::ref(Registry )); } | ||||||||
3078 | false)PassInfo *PI = new PassInfo( "Deduce and propagate attributes (CGSCC pass)" , "attributor-cgscc", &AttributorCGSCCLegacyPass::ID, PassInfo ::NormalCtor_t(callDefaultCtor<AttributorCGSCCLegacyPass> ), false, false); Registry.registerPass(*PI, true); return PI ; } static llvm::once_flag InitializeAttributorCGSCCLegacyPassPassFlag ; void llvm::initializeAttributorCGSCCLegacyPassPass(PassRegistry &Registry) { llvm::call_once(InitializeAttributorCGSCCLegacyPassPassFlag , initializeAttributorCGSCCLegacyPassPassOnce, std::ref(Registry )); } |
1 | //===- Attributor.h --- Module-wide attribute deduction ---------*- 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 | // Attributor: An inter procedural (abstract) "attribute" deduction framework. |
10 | // |
11 | // The Attributor framework is an inter procedural abstract analysis (fixpoint |
12 | // iteration analysis). The goal is to allow easy deduction of new attributes as |
13 | // well as information exchange between abstract attributes in-flight. |
14 | // |
15 | // The Attributor class is the driver and the link between the various abstract |
16 | // attributes. The Attributor will iterate until a fixpoint state is reached by |
17 | // all abstract attributes in-flight, or until it will enforce a pessimistic fix |
18 | // point because an iteration limit is reached. |
19 | // |
20 | // Abstract attributes, derived from the AbstractAttribute class, actually |
21 | // describe properties of the code. They can correspond to actual LLVM-IR |
22 | // attributes, or they can be more general, ultimately unrelated to LLVM-IR |
23 | // attributes. The latter is useful when an abstract attributes provides |
24 | // information to other abstract attributes in-flight but we might not want to |
25 | // manifest the information. The Attributor allows to query in-flight abstract |
26 | // attributes through the `Attributor::getAAFor` method (see the method |
27 | // description for an example). If the method is used by an abstract attribute |
28 | // P, and it results in an abstract attribute Q, the Attributor will |
29 | // automatically capture a potential dependence from Q to P. This dependence |
30 | // will cause P to be reevaluated whenever Q changes in the future. |
31 | // |
32 | // The Attributor will only reevaluate abstract attributes that might have |
33 | // changed since the last iteration. That means that the Attribute will not |
34 | // revisit all instructions/blocks/functions in the module but only query |
35 | // an update from a subset of the abstract attributes. |
36 | // |
37 | // The update method `AbstractAttribute::updateImpl` is implemented by the |
38 | // specific "abstract attribute" subclasses. The method is invoked whenever the |
39 | // currently assumed state (see the AbstractState class) might not be valid |
40 | // anymore. This can, for example, happen if the state was dependent on another |
41 | // abstract attribute that changed. In every invocation, the update method has |
42 | // to adjust the internal state of an abstract attribute to a point that is |
43 | // justifiable by the underlying IR and the current state of abstract attributes |
44 | // in-flight. Since the IR is given and assumed to be valid, the information |
45 | // derived from it can be assumed to hold. However, information derived from |
46 | // other abstract attributes is conditional on various things. If the justifying |
47 | // state changed, the `updateImpl` has to revisit the situation and potentially |
48 | // find another justification or limit the optimistic assumes made. |
49 | // |
50 | // Change is the key in this framework. Until a state of no-change, thus a |
51 | // fixpoint, is reached, the Attributor will query the abstract attributes |
52 | // in-flight to re-evaluate their state. If the (current) state is too |
53 | // optimistic, hence it cannot be justified anymore through other abstract |
54 | // attributes or the state of the IR, the state of the abstract attribute will |
55 | // have to change. Generally, we assume abstract attribute state to be a finite |
56 | // height lattice and the update function to be monotone. However, these |
57 | // conditions are not enforced because the iteration limit will guarantee |
58 | // termination. If an optimistic fixpoint is reached, or a pessimistic fix |
59 | // point is enforced after a timeout, the abstract attributes are tasked to |
60 | // manifest their result in the IR for passes to come. |
61 | // |
62 | // Attribute manifestation is not mandatory. If desired, there is support to |
63 | // generate a single or multiple LLVM-IR attributes already in the helper struct |
64 | // IRAttribute. In the simplest case, a subclass inherits from IRAttribute with |
65 | // a proper Attribute::AttrKind as template parameter. The Attributor |
66 | // manifestation framework will then create and place a new attribute if it is |
67 | // allowed to do so (based on the abstract state). Other use cases can be |
68 | // achieved by overloading AbstractAttribute or IRAttribute methods. |
69 | // |
70 | // |
71 | // The "mechanics" of adding a new "abstract attribute": |
72 | // - Define a class (transitively) inheriting from AbstractAttribute and one |
73 | // (which could be the same) that (transitively) inherits from AbstractState. |
74 | // For the latter, consider the already available BooleanState and |
75 | // {Inc,Dec,Bit}IntegerState if they fit your needs, e.g., you require only a |
76 | // number tracking or bit-encoding. |
77 | // - Implement all pure methods. Also use overloading if the attribute is not |
78 | // conforming with the "default" behavior: A (set of) LLVM-IR attribute(s) for |
79 | // an argument, call site argument, function return value, or function. See |
80 | // the class and method descriptions for more information on the two |
81 | // "Abstract" classes and their respective methods. |
82 | // - Register opportunities for the new abstract attribute in the |
83 | // `Attributor::identifyDefaultAbstractAttributes` method if it should be |
84 | // counted as a 'default' attribute. |
85 | // - Add sufficient tests. |
86 | // - Add a Statistics object for bookkeeping. If it is a simple (set of) |
87 | // attribute(s) manifested through the Attributor manifestation framework, see |
88 | // the bookkeeping function in Attributor.cpp. |
89 | // - If instructions with a certain opcode are interesting to the attribute, add |
90 | // that opcode to the switch in `Attributor::identifyAbstractAttributes`. This |
91 | // will make it possible to query all those instructions through the |
92 | // `InformationCache::getOpcodeInstMapForFunction` interface and eliminate the |
93 | // need to traverse the IR repeatedly. |
94 | // |
95 | //===----------------------------------------------------------------------===// |
96 | |
97 | #ifndef LLVM_TRANSFORMS_IPO_ATTRIBUTOR_H |
98 | #define LLVM_TRANSFORMS_IPO_ATTRIBUTOR_H |
99 | |
100 | #include "llvm/ADT/DenseSet.h" |
101 | #include "llvm/ADT/GraphTraits.h" |
102 | #include "llvm/ADT/MapVector.h" |
103 | #include "llvm/ADT/STLExtras.h" |
104 | #include "llvm/ADT/SetVector.h" |
105 | #include "llvm/ADT/Triple.h" |
106 | #include "llvm/ADT/iterator.h" |
107 | #include "llvm/Analysis/AssumeBundleQueries.h" |
108 | #include "llvm/Analysis/CFG.h" |
109 | #include "llvm/Analysis/CGSCCPassManager.h" |
110 | #include "llvm/Analysis/LazyCallGraph.h" |
111 | #include "llvm/Analysis/LoopInfo.h" |
112 | #include "llvm/Analysis/MustExecute.h" |
113 | #include "llvm/Analysis/OptimizationRemarkEmitter.h" |
114 | #include "llvm/Analysis/PostDominators.h" |
115 | #include "llvm/Analysis/TargetLibraryInfo.h" |
116 | #include "llvm/IR/AbstractCallSite.h" |
117 | #include "llvm/IR/ConstantRange.h" |
118 | #include "llvm/IR/PassManager.h" |
119 | #include "llvm/Support/Allocator.h" |
120 | #include "llvm/Support/Casting.h" |
121 | #include "llvm/Support/GraphWriter.h" |
122 | #include "llvm/Support/TimeProfiler.h" |
123 | #include "llvm/Transforms/Utils/CallGraphUpdater.h" |
124 | |
125 | namespace llvm { |
126 | |
127 | struct AADepGraphNode; |
128 | struct AADepGraph; |
129 | struct Attributor; |
130 | struct AbstractAttribute; |
131 | struct InformationCache; |
132 | struct AAIsDead; |
133 | struct AttributorCallGraph; |
134 | |
135 | class AAManager; |
136 | class AAResults; |
137 | class Function; |
138 | |
139 | /// Abstract Attribute helper functions. |
140 | namespace AA { |
141 | |
142 | /// Return true if \p V is dynamically unique, that is, there are no two |
143 | /// "instances" of \p V at runtime with different values. |
144 | bool isDynamicallyUnique(Attributor &A, const AbstractAttribute &QueryingAA, |
145 | const Value &V); |
146 | |
147 | /// Return true if \p V is a valid value in \p Scope, that is a constant or an |
148 | /// instruction/argument of \p Scope. |
149 | bool isValidInScope(const Value &V, const Function *Scope); |
150 | |
151 | /// Return true if \p V is a valid value at position \p CtxI, that is a |
152 | /// constant, an argument of the same function as \p CtxI, or an instruction in |
153 | /// that function that dominates \p CtxI. |
154 | bool isValidAtPosition(const Value &V, const Instruction &CtxI, |
155 | InformationCache &InfoCache); |
156 | |
157 | /// Try to convert \p V to type \p Ty without introducing new instructions. If |
158 | /// this is not possible return `nullptr`. Note: this function basically knows |
159 | /// how to cast various constants. |
160 | Value *getWithType(Value &V, Type &Ty); |
161 | |
162 | /// Return the combination of \p A and \p B such that the result is a possible |
163 | /// value of both. \p B is potentially casted to match the type \p Ty or the |
164 | /// type of \p A if \p Ty is null. |
165 | /// |
166 | /// Examples: |
167 | /// X + none => X |
168 | /// not_none + undef => not_none |
169 | /// V1 + V2 => nullptr |
170 | Optional<Value *> |
171 | combineOptionalValuesInAAValueLatice(const Optional<Value *> &A, |
172 | const Optional<Value *> &B, Type *Ty); |
173 | |
174 | /// Return the initial value of \p Obj with type \p Ty if that is a constant. |
175 | Constant *getInitialValueForObj(Value &Obj, Type &Ty); |
176 | |
177 | /// Collect all potential underlying objects of \p Ptr at position \p CtxI in |
178 | /// \p Objects. Assumed information is used and dependences onto \p QueryingAA |
179 | /// are added appropriately. |
180 | /// |
181 | /// \returns True if \p Objects contains all assumed underlying objects, and |
182 | /// false if something went wrong and the objects could not be |
183 | /// determined. |
184 | bool getAssumedUnderlyingObjects(Attributor &A, const Value &Ptr, |
185 | SmallVectorImpl<Value *> &Objects, |
186 | const AbstractAttribute &QueryingAA, |
187 | const Instruction *CtxI); |
188 | |
189 | /// Collect all potential values of the one stored by \p SI into |
190 | /// \p PotentialCopies. That is, the only copies that were made via the |
191 | /// store are assumed to be known and all in \p PotentialCopies. Dependences |
192 | /// onto \p QueryingAA are properly tracked, \p UsedAssumedInformation will |
193 | /// inform the caller if assumed information was used. |
194 | /// |
195 | /// \returns True if the assumed potential copies are all in \p PotentialCopies, |
196 | /// false if something went wrong and the copies could not be |
197 | /// determined. |
198 | bool getPotentialCopiesOfStoredValue( |
199 | Attributor &A, StoreInst &SI, SmallSetVector<Value *, 4> &PotentialCopies, |
200 | const AbstractAttribute &QueryingAA, bool &UsedAssumedInformation); |
201 | |
202 | } // namespace AA |
203 | |
204 | /// The value passed to the line option that defines the maximal initialization |
205 | /// chain length. |
206 | extern unsigned MaxInitializationChainLength; |
207 | |
208 | ///{ |
209 | enum class ChangeStatus { |
210 | CHANGED, |
211 | UNCHANGED, |
212 | }; |
213 | |
214 | ChangeStatus operator|(ChangeStatus l, ChangeStatus r); |
215 | ChangeStatus &operator|=(ChangeStatus &l, ChangeStatus r); |
216 | ChangeStatus operator&(ChangeStatus l, ChangeStatus r); |
217 | ChangeStatus &operator&=(ChangeStatus &l, ChangeStatus r); |
218 | |
219 | enum class DepClassTy { |
220 | REQUIRED, ///< The target cannot be valid if the source is not. |
221 | OPTIONAL, ///< The target may be valid if the source is not. |
222 | NONE, ///< Do not track a dependence between source and target. |
223 | }; |
224 | ///} |
225 | |
226 | /// The data structure for the nodes of a dependency graph |
227 | struct AADepGraphNode { |
228 | public: |
229 | virtual ~AADepGraphNode(){}; |
230 | using DepTy = PointerIntPair<AADepGraphNode *, 1>; |
231 | |
232 | protected: |
233 | /// Set of dependency graph nodes which should be updated if this one |
234 | /// is updated. The bit encodes if it is optional. |
235 | TinyPtrVector<DepTy> Deps; |
236 | |
237 | static AADepGraphNode *DepGetVal(DepTy &DT) { return DT.getPointer(); } |
238 | static AbstractAttribute *DepGetValAA(DepTy &DT) { |
239 | return cast<AbstractAttribute>(DT.getPointer()); |
240 | } |
241 | |
242 | operator AbstractAttribute *() { return cast<AbstractAttribute>(this); } |
243 | |
244 | public: |
245 | using iterator = |
246 | mapped_iterator<TinyPtrVector<DepTy>::iterator, decltype(&DepGetVal)>; |
247 | using aaiterator = |
248 | mapped_iterator<TinyPtrVector<DepTy>::iterator, decltype(&DepGetValAA)>; |
249 | |
250 | aaiterator begin() { return aaiterator(Deps.begin(), &DepGetValAA); } |
251 | aaiterator end() { return aaiterator(Deps.end(), &DepGetValAA); } |
252 | iterator child_begin() { return iterator(Deps.begin(), &DepGetVal); } |
253 | iterator child_end() { return iterator(Deps.end(), &DepGetVal); } |
254 | |
255 | virtual void print(raw_ostream &OS) const { OS << "AADepNode Impl\n"; } |
256 | TinyPtrVector<DepTy> &getDeps() { return Deps; } |
257 | |
258 | friend struct Attributor; |
259 | friend struct AADepGraph; |
260 | }; |
261 | |
262 | /// The data structure for the dependency graph |
263 | /// |
264 | /// Note that in this graph if there is an edge from A to B (A -> B), |
265 | /// then it means that B depends on A, and when the state of A is |
266 | /// updated, node B should also be updated |
267 | struct AADepGraph { |
268 | AADepGraph() {} |
269 | ~AADepGraph() {} |
270 | |
271 | using DepTy = AADepGraphNode::DepTy; |
272 | static AADepGraphNode *DepGetVal(DepTy &DT) { return DT.getPointer(); } |
273 | using iterator = |
274 | mapped_iterator<TinyPtrVector<DepTy>::iterator, decltype(&DepGetVal)>; |
275 | |
276 | /// There is no root node for the dependency graph. But the SCCIterator |
277 | /// requires a single entry point, so we maintain a fake("synthetic") root |
278 | /// node that depends on every node. |
279 | AADepGraphNode SyntheticRoot; |
280 | AADepGraphNode *GetEntryNode() { return &SyntheticRoot; } |
281 | |
282 | iterator begin() { return SyntheticRoot.child_begin(); } |
283 | iterator end() { return SyntheticRoot.child_end(); } |
284 | |
285 | void viewGraph(); |
286 | |
287 | /// Dump graph to file |
288 | void dumpGraph(); |
289 | |
290 | /// Print dependency graph |
291 | void print(); |
292 | }; |
293 | |
294 | /// Helper to describe and deal with positions in the LLVM-IR. |
295 | /// |
296 | /// A position in the IR is described by an anchor value and an "offset" that |
297 | /// could be the argument number, for call sites and arguments, or an indicator |
298 | /// of the "position kind". The kinds, specified in the Kind enum below, include |
299 | /// the locations in the attribute list, i.a., function scope and return value, |
300 | /// as well as a distinction between call sites and functions. Finally, there |
301 | /// are floating values that do not have a corresponding attribute list |
302 | /// position. |
303 | struct IRPosition { |
304 | // NOTE: In the future this definition can be changed to support recursive |
305 | // functions. |
306 | using CallBaseContext = CallBase; |
307 | |
308 | /// The positions we distinguish in the IR. |
309 | enum Kind : char { |
310 | IRP_INVALID, ///< An invalid position. |
311 | IRP_FLOAT, ///< A position that is not associated with a spot suitable |
312 | ///< for attributes. This could be any value or instruction. |
313 | IRP_RETURNED, ///< An attribute for the function return value. |
314 | IRP_CALL_SITE_RETURNED, ///< An attribute for a call site return value. |
315 | IRP_FUNCTION, ///< An attribute for a function (scope). |
316 | IRP_CALL_SITE, ///< An attribute for a call site (function scope). |
317 | IRP_ARGUMENT, ///< An attribute for a function argument. |
318 | IRP_CALL_SITE_ARGUMENT, ///< An attribute for a call site argument. |
319 | }; |
320 | |
321 | /// Default constructor available to create invalid positions implicitly. All |
322 | /// other positions need to be created explicitly through the appropriate |
323 | /// static member function. |
324 | IRPosition() : Enc(nullptr, ENC_VALUE) { verify(); } |
325 | |
326 | /// Create a position describing the value of \p V. |
327 | static const IRPosition value(const Value &V, |
328 | const CallBaseContext *CBContext = nullptr) { |
329 | if (auto *Arg = dyn_cast<Argument>(&V)) |
330 | return IRPosition::argument(*Arg, CBContext); |
331 | if (auto *CB = dyn_cast<CallBase>(&V)) |
332 | return IRPosition::callsite_returned(*CB); |
333 | return IRPosition(const_cast<Value &>(V), IRP_FLOAT, CBContext); |
334 | } |
335 | |
336 | /// Create a position describing the function scope of \p F. |
337 | /// \p CBContext is used for call base specific analysis. |
338 | static const IRPosition function(const Function &F, |
339 | const CallBaseContext *CBContext = nullptr) { |
340 | return IRPosition(const_cast<Function &>(F), IRP_FUNCTION, CBContext); |
341 | } |
342 | |
343 | /// Create a position describing the returned value of \p F. |
344 | /// \p CBContext is used for call base specific analysis. |
345 | static const IRPosition returned(const Function &F, |
346 | const CallBaseContext *CBContext = nullptr) { |
347 | return IRPosition(const_cast<Function &>(F), IRP_RETURNED, CBContext); |
348 | } |
349 | |
350 | /// Create a position describing the argument \p Arg. |
351 | /// \p CBContext is used for call base specific analysis. |
352 | static const IRPosition argument(const Argument &Arg, |
353 | const CallBaseContext *CBContext = nullptr) { |
354 | return IRPosition(const_cast<Argument &>(Arg), IRP_ARGUMENT, CBContext); |
355 | } |
356 | |
357 | /// Create a position describing the function scope of \p CB. |
358 | static const IRPosition callsite_function(const CallBase &CB) { |
359 | return IRPosition(const_cast<CallBase &>(CB), IRP_CALL_SITE); |
360 | } |
361 | |
362 | /// Create a position describing the returned value of \p CB. |
363 | static const IRPosition callsite_returned(const CallBase &CB) { |
364 | return IRPosition(const_cast<CallBase &>(CB), IRP_CALL_SITE_RETURNED); |
365 | } |
366 | |
367 | /// Create a position describing the argument of \p CB at position \p ArgNo. |
368 | static const IRPosition callsite_argument(const CallBase &CB, |
369 | unsigned ArgNo) { |
370 | return IRPosition(const_cast<Use &>(CB.getArgOperandUse(ArgNo)), |
371 | IRP_CALL_SITE_ARGUMENT); |
372 | } |
373 | |
374 | /// Create a position describing the argument of \p ACS at position \p ArgNo. |
375 | static const IRPosition callsite_argument(AbstractCallSite ACS, |
376 | unsigned ArgNo) { |
377 | if (ACS.getNumArgOperands() <= ArgNo) |
378 | return IRPosition(); |
379 | int CSArgNo = ACS.getCallArgOperandNo(ArgNo); |
380 | if (CSArgNo >= 0) |
381 | return IRPosition::callsite_argument( |
382 | cast<CallBase>(*ACS.getInstruction()), CSArgNo); |
383 | return IRPosition(); |
384 | } |
385 | |
386 | /// Create a position with function scope matching the "context" of \p IRP. |
387 | /// If \p IRP is a call site (see isAnyCallSitePosition()) then the result |
388 | /// will be a call site position, otherwise the function position of the |
389 | /// associated function. |
390 | static const IRPosition |
391 | function_scope(const IRPosition &IRP, |
392 | const CallBaseContext *CBContext = nullptr) { |
393 | if (IRP.isAnyCallSitePosition()) { |
394 | return IRPosition::callsite_function( |
395 | cast<CallBase>(IRP.getAnchorValue())); |
396 | } |
397 | assert(IRP.getAssociatedFunction())((void)0); |
398 | return IRPosition::function(*IRP.getAssociatedFunction(), CBContext); |
399 | } |
400 | |
401 | bool operator==(const IRPosition &RHS) const { |
402 | return Enc == RHS.Enc && RHS.CBContext == CBContext; |
403 | } |
404 | bool operator!=(const IRPosition &RHS) const { return !(*this == RHS); } |
405 | |
406 | /// Return the value this abstract attribute is anchored with. |
407 | /// |
408 | /// The anchor value might not be the associated value if the latter is not |
409 | /// sufficient to determine where arguments will be manifested. This is, so |
410 | /// far, only the case for call site arguments as the value is not sufficient |
411 | /// to pinpoint them. Instead, we can use the call site as an anchor. |
412 | Value &getAnchorValue() const { |
413 | switch (getEncodingBits()) { |
414 | case ENC_VALUE: |
415 | case ENC_RETURNED_VALUE: |
416 | case ENC_FLOATING_FUNCTION: |
417 | return *getAsValuePtr(); |
418 | case ENC_CALL_SITE_ARGUMENT_USE: |
419 | return *(getAsUsePtr()->getUser()); |
420 | default: |
421 | llvm_unreachable("Unkown encoding!")__builtin_unreachable(); |
422 | }; |
423 | } |
424 | |
425 | /// Return the associated function, if any. |
426 | Function *getAssociatedFunction() const { |
427 | if (auto *CB = dyn_cast<CallBase>(&getAnchorValue())) { |
428 | // We reuse the logic that associates callback calles to arguments of a |
429 | // call site here to identify the callback callee as the associated |
430 | // function. |
431 | if (Argument *Arg = getAssociatedArgument()) |
432 | return Arg->getParent(); |
433 | return CB->getCalledFunction(); |
434 | } |
435 | return getAnchorScope(); |
436 | } |
437 | |
438 | /// Return the associated argument, if any. |
439 | Argument *getAssociatedArgument() const; |
440 | |
441 | /// Return true if the position refers to a function interface, that is the |
442 | /// function scope, the function return, or an argument. |
443 | bool isFnInterfaceKind() const { |
444 | switch (getPositionKind()) { |
445 | case IRPosition::IRP_FUNCTION: |
446 | case IRPosition::IRP_RETURNED: |
447 | case IRPosition::IRP_ARGUMENT: |
448 | return true; |
449 | default: |
450 | return false; |
451 | } |
452 | } |
453 | |
454 | /// Return the Function surrounding the anchor value. |
455 | Function *getAnchorScope() const { |
456 | Value &V = getAnchorValue(); |
457 | if (isa<Function>(V)) |
458 | return &cast<Function>(V); |
459 | if (isa<Argument>(V)) |
460 | return cast<Argument>(V).getParent(); |
461 | if (isa<Instruction>(V)) |
462 | return cast<Instruction>(V).getFunction(); |
463 | return nullptr; |
464 | } |
465 | |
466 | /// Return the context instruction, if any. |
467 | Instruction *getCtxI() const { |
468 | Value &V = getAnchorValue(); |
469 | if (auto *I = dyn_cast<Instruction>(&V)) |
470 | return I; |
471 | if (auto *Arg = dyn_cast<Argument>(&V)) |
472 | if (!Arg->getParent()->isDeclaration()) |
473 | return &Arg->getParent()->getEntryBlock().front(); |
474 | if (auto *F = dyn_cast<Function>(&V)) |
475 | if (!F->isDeclaration()) |
476 | return &(F->getEntryBlock().front()); |
477 | return nullptr; |
478 | } |
479 | |
480 | /// Return the value this abstract attribute is associated with. |
481 | Value &getAssociatedValue() const { |
482 | if (getCallSiteArgNo() < 0 || isa<Argument>(&getAnchorValue())) |
483 | return getAnchorValue(); |
484 | assert(isa<CallBase>(&getAnchorValue()) && "Expected a call base!")((void)0); |
485 | return *cast<CallBase>(&getAnchorValue()) |
486 | ->getArgOperand(getCallSiteArgNo()); |
487 | } |
488 | |
489 | /// Return the type this abstract attribute is associated with. |
490 | Type *getAssociatedType() const { |
491 | if (getPositionKind() == IRPosition::IRP_RETURNED) |
492 | return getAssociatedFunction()->getReturnType(); |
493 | return getAssociatedValue().getType(); |
494 | } |
495 | |
496 | /// Return the callee argument number of the associated value if it is an |
497 | /// argument or call site argument, otherwise a negative value. In contrast to |
498 | /// `getCallSiteArgNo` this method will always return the "argument number" |
499 | /// from the perspective of the callee. This may not the same as the call site |
500 | /// if this is a callback call. |
501 | int getCalleeArgNo() const { |
502 | return getArgNo(/* CallbackCalleeArgIfApplicable */ true); |
503 | } |
504 | |
505 | /// Return the call site argument number of the associated value if it is an |
506 | /// argument or call site argument, otherwise a negative value. In contrast to |
507 | /// `getCalleArgNo` this method will always return the "operand number" from |
508 | /// the perspective of the call site. This may not the same as the callee |
509 | /// perspective if this is a callback call. |
510 | int getCallSiteArgNo() const { |
511 | return getArgNo(/* CallbackCalleeArgIfApplicable */ false); |
512 | } |
513 | |
514 | /// Return the index in the attribute list for this position. |
515 | unsigned getAttrIdx() const { |
516 | switch (getPositionKind()) { |
517 | case IRPosition::IRP_INVALID: |
518 | case IRPosition::IRP_FLOAT: |
519 | break; |
520 | case IRPosition::IRP_FUNCTION: |
521 | case IRPosition::IRP_CALL_SITE: |
522 | return AttributeList::FunctionIndex; |
523 | case IRPosition::IRP_RETURNED: |
524 | case IRPosition::IRP_CALL_SITE_RETURNED: |
525 | return AttributeList::ReturnIndex; |
526 | case IRPosition::IRP_ARGUMENT: |
527 | case IRPosition::IRP_CALL_SITE_ARGUMENT: |
528 | return getCallSiteArgNo() + AttributeList::FirstArgIndex; |
529 | } |
530 | llvm_unreachable(__builtin_unreachable() |
531 | "There is no attribute index for a floating or invalid position!")__builtin_unreachable(); |
532 | } |
533 | |
534 | /// Return the associated position kind. |
535 | Kind getPositionKind() const { |
536 | char EncodingBits = getEncodingBits(); |
537 | if (EncodingBits == ENC_CALL_SITE_ARGUMENT_USE) |
538 | return IRP_CALL_SITE_ARGUMENT; |
539 | if (EncodingBits == ENC_FLOATING_FUNCTION) |
540 | return IRP_FLOAT; |
541 | |
542 | Value *V = getAsValuePtr(); |
543 | if (!V) |
544 | return IRP_INVALID; |
545 | if (isa<Argument>(V)) |
546 | return IRP_ARGUMENT; |
547 | if (isa<Function>(V)) |
548 | return isReturnPosition(EncodingBits) ? IRP_RETURNED : IRP_FUNCTION; |
549 | if (isa<CallBase>(V)) |
550 | return isReturnPosition(EncodingBits) ? IRP_CALL_SITE_RETURNED |
551 | : IRP_CALL_SITE; |
552 | return IRP_FLOAT; |
553 | } |
554 | |
555 | /// TODO: Figure out if the attribute related helper functions should live |
556 | /// here or somewhere else. |
557 | |
558 | /// Return true if any kind in \p AKs existing in the IR at a position that |
559 | /// will affect this one. See also getAttrs(...). |
560 | /// \param IgnoreSubsumingPositions Flag to determine if subsuming positions, |
561 | /// e.g., the function position if this is an |
562 | /// argument position, should be ignored. |
563 | bool hasAttr(ArrayRef<Attribute::AttrKind> AKs, |
564 | bool IgnoreSubsumingPositions = false, |
565 | Attributor *A = nullptr) const; |
566 | |
567 | /// Return the attributes of any kind in \p AKs existing in the IR at a |
568 | /// position that will affect this one. While each position can only have a |
569 | /// single attribute of any kind in \p AKs, there are "subsuming" positions |
570 | /// that could have an attribute as well. This method returns all attributes |
571 | /// found in \p Attrs. |
572 | /// \param IgnoreSubsumingPositions Flag to determine if subsuming positions, |
573 | /// e.g., the function position if this is an |
574 | /// argument position, should be ignored. |
575 | void getAttrs(ArrayRef<Attribute::AttrKind> AKs, |
576 | SmallVectorImpl<Attribute> &Attrs, |
577 | bool IgnoreSubsumingPositions = false, |
578 | Attributor *A = nullptr) const; |
579 | |
580 | /// Remove the attribute of kind \p AKs existing in the IR at this position. |
581 | void removeAttrs(ArrayRef<Attribute::AttrKind> AKs) const { |
582 | if (getPositionKind() == IRP_INVALID || getPositionKind() == IRP_FLOAT) |
583 | return; |
584 | |
585 | AttributeList AttrList; |
586 | auto *CB = dyn_cast<CallBase>(&getAnchorValue()); |
587 | if (CB) |
588 | AttrList = CB->getAttributes(); |
589 | else |
590 | AttrList = getAssociatedFunction()->getAttributes(); |
591 | |
592 | LLVMContext &Ctx = getAnchorValue().getContext(); |
593 | for (Attribute::AttrKind AK : AKs) |
594 | AttrList = AttrList.removeAttribute(Ctx, getAttrIdx(), AK); |
595 | |
596 | if (CB) |
597 | CB->setAttributes(AttrList); |
598 | else |
599 | getAssociatedFunction()->setAttributes(AttrList); |
600 | } |
601 | |
602 | bool isAnyCallSitePosition() const { |
603 | switch (getPositionKind()) { |
604 | case IRPosition::IRP_CALL_SITE: |
605 | case IRPosition::IRP_CALL_SITE_RETURNED: |
606 | case IRPosition::IRP_CALL_SITE_ARGUMENT: |
607 | return true; |
608 | default: |
609 | return false; |
610 | } |
611 | } |
612 | |
613 | /// Return true if the position is an argument or call site argument. |
614 | bool isArgumentPosition() const { |
615 | switch (getPositionKind()) { |
616 | case IRPosition::IRP_ARGUMENT: |
617 | case IRPosition::IRP_CALL_SITE_ARGUMENT: |
618 | return true; |
619 | default: |
620 | return false; |
621 | } |
622 | } |
623 | |
624 | /// Return the same position without the call base context. |
625 | IRPosition stripCallBaseContext() const { |
626 | IRPosition Result = *this; |
627 | Result.CBContext = nullptr; |
628 | return Result; |
629 | } |
630 | |
631 | /// Get the call base context from the position. |
632 | const CallBaseContext *getCallBaseContext() const { return CBContext; } |
633 | |
634 | /// Check if the position has any call base context. |
635 | bool hasCallBaseContext() const { return CBContext != nullptr; } |
636 | |
637 | /// Special DenseMap key values. |
638 | /// |
639 | ///{ |
640 | static const IRPosition EmptyKey; |
641 | static const IRPosition TombstoneKey; |
642 | ///} |
643 | |
644 | /// Conversion into a void * to allow reuse of pointer hashing. |
645 | operator void *() const { return Enc.getOpaqueValue(); } |
646 | |
647 | private: |
648 | /// Private constructor for special values only! |
649 | explicit IRPosition(void *Ptr, const CallBaseContext *CBContext = nullptr) |
650 | : CBContext(CBContext) { |
651 | Enc.setFromOpaqueValue(Ptr); |
652 | } |
653 | |
654 | /// IRPosition anchored at \p AnchorVal with kind/argument numbet \p PK. |
655 | explicit IRPosition(Value &AnchorVal, Kind PK, |
656 | const CallBaseContext *CBContext = nullptr) |
657 | : CBContext(CBContext) { |
658 | switch (PK) { |
659 | case IRPosition::IRP_INVALID: |
660 | llvm_unreachable("Cannot create invalid IRP with an anchor value!")__builtin_unreachable(); |
661 | break; |
662 | case IRPosition::IRP_FLOAT: |
663 | // Special case for floating functions. |
664 | if (isa<Function>(AnchorVal)) |
665 | Enc = {&AnchorVal, ENC_FLOATING_FUNCTION}; |
666 | else |
667 | Enc = {&AnchorVal, ENC_VALUE}; |
668 | break; |
669 | case IRPosition::IRP_FUNCTION: |
670 | case IRPosition::IRP_CALL_SITE: |
671 | Enc = {&AnchorVal, ENC_VALUE}; |
672 | break; |
673 | case IRPosition::IRP_RETURNED: |
674 | case IRPosition::IRP_CALL_SITE_RETURNED: |
675 | Enc = {&AnchorVal, ENC_RETURNED_VALUE}; |
676 | break; |
677 | case IRPosition::IRP_ARGUMENT: |
678 | Enc = {&AnchorVal, ENC_VALUE}; |
679 | break; |
680 | case IRPosition::IRP_CALL_SITE_ARGUMENT: |
681 | llvm_unreachable(__builtin_unreachable() |
682 | "Cannot create call site argument IRP with an anchor value!")__builtin_unreachable(); |
683 | break; |
684 | } |
685 | verify(); |
686 | } |
687 | |
688 | /// Return the callee argument number of the associated value if it is an |
689 | /// argument or call site argument. See also `getCalleeArgNo` and |
690 | /// `getCallSiteArgNo`. |
691 | int getArgNo(bool CallbackCalleeArgIfApplicable) const { |
692 | if (CallbackCalleeArgIfApplicable) |
693 | if (Argument *Arg = getAssociatedArgument()) |
694 | return Arg->getArgNo(); |
695 | switch (getPositionKind()) { |
696 | case IRPosition::IRP_ARGUMENT: |
697 | return cast<Argument>(getAsValuePtr())->getArgNo(); |
698 | case IRPosition::IRP_CALL_SITE_ARGUMENT: { |
699 | Use &U = *getAsUsePtr(); |
700 | return cast<CallBase>(U.getUser())->getArgOperandNo(&U); |
701 | } |
702 | default: |
703 | return -1; |
704 | } |
705 | } |
706 | |
707 | /// IRPosition for the use \p U. The position kind \p PK needs to be |
708 | /// IRP_CALL_SITE_ARGUMENT, the anchor value is the user, the associated value |
709 | /// the used value. |
710 | explicit IRPosition(Use &U, Kind PK) { |
711 | assert(PK == IRP_CALL_SITE_ARGUMENT &&((void)0) |
712 | "Use constructor is for call site arguments only!")((void)0); |
713 | Enc = {&U, ENC_CALL_SITE_ARGUMENT_USE}; |
714 | verify(); |
715 | } |
716 | |
717 | /// Verify internal invariants. |
718 | void verify(); |
719 | |
720 | /// Return the attributes of kind \p AK existing in the IR as attribute. |
721 | bool getAttrsFromIRAttr(Attribute::AttrKind AK, |
722 | SmallVectorImpl<Attribute> &Attrs) const; |
723 | |
724 | /// Return the attributes of kind \p AK existing in the IR as operand bundles |
725 | /// of an llvm.assume. |
726 | bool getAttrsFromAssumes(Attribute::AttrKind AK, |
727 | SmallVectorImpl<Attribute> &Attrs, |
728 | Attributor &A) const; |
729 | |
730 | /// Return the underlying pointer as Value *, valid for all positions but |
731 | /// IRP_CALL_SITE_ARGUMENT. |
732 | Value *getAsValuePtr() const { |
733 | assert(getEncodingBits() != ENC_CALL_SITE_ARGUMENT_USE &&((void)0) |
734 | "Not a value pointer!")((void)0); |
735 | return reinterpret_cast<Value *>(Enc.getPointer()); |
736 | } |
737 | |
738 | /// Return the underlying pointer as Use *, valid only for |
739 | /// IRP_CALL_SITE_ARGUMENT positions. |
740 | Use *getAsUsePtr() const { |
741 | assert(getEncodingBits() == ENC_CALL_SITE_ARGUMENT_USE &&((void)0) |
742 | "Not a value pointer!")((void)0); |
743 | return reinterpret_cast<Use *>(Enc.getPointer()); |
744 | } |
745 | |
746 | /// Return true if \p EncodingBits describe a returned or call site returned |
747 | /// position. |
748 | static bool isReturnPosition(char EncodingBits) { |
749 | return EncodingBits == ENC_RETURNED_VALUE; |
750 | } |
751 | |
752 | /// Return true if the encoding bits describe a returned or call site returned |
753 | /// position. |
754 | bool isReturnPosition() const { return isReturnPosition(getEncodingBits()); } |
755 | |
756 | /// The encoding of the IRPosition is a combination of a pointer and two |
757 | /// encoding bits. The values of the encoding bits are defined in the enum |
758 | /// below. The pointer is either a Value* (for the first three encoding bit |
759 | /// combinations) or Use* (for ENC_CALL_SITE_ARGUMENT_USE). |
760 | /// |
761 | ///{ |
762 | enum { |
763 | ENC_VALUE = 0b00, |
764 | ENC_RETURNED_VALUE = 0b01, |
765 | ENC_FLOATING_FUNCTION = 0b10, |
766 | ENC_CALL_SITE_ARGUMENT_USE = 0b11, |
767 | }; |
768 | |
769 | // Reserve the maximal amount of bits so there is no need to mask out the |
770 | // remaining ones. We will not encode anything else in the pointer anyway. |
771 | static constexpr int NumEncodingBits = |
772 | PointerLikeTypeTraits<void *>::NumLowBitsAvailable; |
773 | static_assert(NumEncodingBits >= 2, "At least two bits are required!"); |
774 | |
775 | /// The pointer with the encoding bits. |
776 | PointerIntPair<void *, NumEncodingBits, char> Enc; |
777 | ///} |
778 | |
779 | /// Call base context. Used for callsite specific analysis. |
780 | const CallBaseContext *CBContext = nullptr; |
781 | |
782 | /// Return the encoding bits. |
783 | char getEncodingBits() const { return Enc.getInt(); } |
784 | }; |
785 | |
786 | /// Helper that allows IRPosition as a key in a DenseMap. |
787 | template <> struct DenseMapInfo<IRPosition> { |
788 | static inline IRPosition getEmptyKey() { return IRPosition::EmptyKey; } |
789 | static inline IRPosition getTombstoneKey() { |
790 | return IRPosition::TombstoneKey; |
791 | } |
792 | static unsigned getHashValue(const IRPosition &IRP) { |
793 | return (DenseMapInfo<void *>::getHashValue(IRP) << 4) ^ |
794 | (DenseMapInfo<Value *>::getHashValue(IRP.getCallBaseContext())); |
795 | } |
796 | |
797 | static bool isEqual(const IRPosition &a, const IRPosition &b) { |
798 | return a == b; |
799 | } |
800 | }; |
801 | |
802 | /// A visitor class for IR positions. |
803 | /// |
804 | /// Given a position P, the SubsumingPositionIterator allows to visit "subsuming |
805 | /// positions" wrt. attributes/information. Thus, if a piece of information |
806 | /// holds for a subsuming position, it also holds for the position P. |
807 | /// |
808 | /// The subsuming positions always include the initial position and then, |
809 | /// depending on the position kind, additionally the following ones: |
810 | /// - for IRP_RETURNED: |
811 | /// - the function (IRP_FUNCTION) |
812 | /// - for IRP_ARGUMENT: |
813 | /// - the function (IRP_FUNCTION) |
814 | /// - for IRP_CALL_SITE: |
815 | /// - the callee (IRP_FUNCTION), if known |
816 | /// - for IRP_CALL_SITE_RETURNED: |
817 | /// - the callee (IRP_RETURNED), if known |
818 | /// - the call site (IRP_FUNCTION) |
819 | /// - the callee (IRP_FUNCTION), if known |
820 | /// - for IRP_CALL_SITE_ARGUMENT: |
821 | /// - the argument of the callee (IRP_ARGUMENT), if known |
822 | /// - the callee (IRP_FUNCTION), if known |
823 | /// - the position the call site argument is associated with if it is not |
824 | /// anchored to the call site, e.g., if it is an argument then the argument |
825 | /// (IRP_ARGUMENT) |
826 | class SubsumingPositionIterator { |
827 | SmallVector<IRPosition, 4> IRPositions; |
828 | using iterator = decltype(IRPositions)::iterator; |
829 | |
830 | public: |
831 | SubsumingPositionIterator(const IRPosition &IRP); |
832 | iterator begin() { return IRPositions.begin(); } |
833 | iterator end() { return IRPositions.end(); } |
834 | }; |
835 | |
836 | /// Wrapper for FunctoinAnalysisManager. |
837 | struct AnalysisGetter { |
838 | template <typename Analysis> |
839 | typename Analysis::Result *getAnalysis(const Function &F) { |
840 | if (!FAM || !F.getParent()) |
841 | return nullptr; |
842 | return &FAM->getResult<Analysis>(const_cast<Function &>(F)); |
843 | } |
844 | |
845 | AnalysisGetter(FunctionAnalysisManager &FAM) : FAM(&FAM) {} |
846 | AnalysisGetter() {} |
847 | |
848 | private: |
849 | FunctionAnalysisManager *FAM = nullptr; |
850 | }; |
851 | |
852 | /// Data structure to hold cached (LLVM-IR) information. |
853 | /// |
854 | /// All attributes are given an InformationCache object at creation time to |
855 | /// avoid inspection of the IR by all of them individually. This default |
856 | /// InformationCache will hold information required by 'default' attributes, |
857 | /// thus the ones deduced when Attributor::identifyDefaultAbstractAttributes(..) |
858 | /// is called. |
859 | /// |
860 | /// If custom abstract attributes, registered manually through |
861 | /// Attributor::registerAA(...), need more information, especially if it is not |
862 | /// reusable, it is advised to inherit from the InformationCache and cast the |
863 | /// instance down in the abstract attributes. |
864 | struct InformationCache { |
865 | InformationCache(const Module &M, AnalysisGetter &AG, |
866 | BumpPtrAllocator &Allocator, SetVector<Function *> *CGSCC) |
867 | : DL(M.getDataLayout()), Allocator(Allocator), |
868 | Explorer( |
869 | /* ExploreInterBlock */ true, /* ExploreCFGForward */ true, |
870 | /* ExploreCFGBackward */ true, |
871 | /* LIGetter */ |
872 | [&](const Function &F) { return AG.getAnalysis<LoopAnalysis>(F); }, |
873 | /* DTGetter */ |
874 | [&](const Function &F) { |
875 | return AG.getAnalysis<DominatorTreeAnalysis>(F); |
876 | }, |
877 | /* PDTGetter */ |
878 | [&](const Function &F) { |
879 | return AG.getAnalysis<PostDominatorTreeAnalysis>(F); |
880 | }), |
881 | AG(AG), CGSCC(CGSCC), TargetTriple(M.getTargetTriple()) { |
882 | if (CGSCC) |
883 | initializeModuleSlice(*CGSCC); |
884 | } |
885 | |
886 | ~InformationCache() { |
887 | // The FunctionInfo objects are allocated via a BumpPtrAllocator, we call |
888 | // the destructor manually. |
889 | for (auto &It : FuncInfoMap) |
890 | It.getSecond()->~FunctionInfo(); |
891 | } |
892 | |
893 | /// Apply \p CB to all uses of \p F. If \p LookThroughConstantExprUses is |
894 | /// true, constant expression users are not given to \p CB but their uses are |
895 | /// traversed transitively. |
896 | template <typename CBTy> |
897 | static void foreachUse(Function &F, CBTy CB, |
898 | bool LookThroughConstantExprUses = true) { |
899 | SmallVector<Use *, 8> Worklist(make_pointer_range(F.uses())); |
900 | |
901 | for (unsigned Idx = 0; Idx < Worklist.size(); ++Idx) { |
902 | Use &U = *Worklist[Idx]; |
903 | |
904 | // Allow use in constant bitcasts and simply look through them. |
905 | if (LookThroughConstantExprUses && isa<ConstantExpr>(U.getUser())) { |
906 | for (Use &CEU : cast<ConstantExpr>(U.getUser())->uses()) |
907 | Worklist.push_back(&CEU); |
908 | continue; |
909 | } |
910 | |
911 | CB(U); |
912 | } |
913 | } |
914 | |
915 | /// Initialize the ModuleSlice member based on \p SCC. ModuleSlices contains |
916 | /// (a subset of) all functions that we can look at during this SCC traversal. |
917 | /// This includes functions (transitively) called from the SCC and the |
918 | /// (transitive) callers of SCC functions. We also can look at a function if |
919 | /// there is a "reference edge", i.a., if the function somehow uses (!=calls) |
920 | /// a function in the SCC or a caller of a function in the SCC. |
921 | void initializeModuleSlice(SetVector<Function *> &SCC) { |
922 | ModuleSlice.insert(SCC.begin(), SCC.end()); |
923 | |
924 | SmallPtrSet<Function *, 16> Seen; |
925 | SmallVector<Function *, 16> Worklist(SCC.begin(), SCC.end()); |
926 | while (!Worklist.empty()) { |
927 | Function *F = Worklist.pop_back_val(); |
928 | ModuleSlice.insert(F); |
929 | |
930 | for (Instruction &I : instructions(*F)) |
931 | if (auto *CB = dyn_cast<CallBase>(&I)) |
932 | if (Function *Callee = CB->getCalledFunction()) |
933 | if (Seen.insert(Callee).second) |
934 | Worklist.push_back(Callee); |
935 | } |
936 | |
937 | Seen.clear(); |
938 | Worklist.append(SCC.begin(), SCC.end()); |
939 | while (!Worklist.empty()) { |
940 | Function *F = Worklist.pop_back_val(); |
941 | ModuleSlice.insert(F); |
942 | |
943 | // Traverse all transitive uses. |
944 | foreachUse(*F, [&](Use &U) { |
945 | if (auto *UsrI = dyn_cast<Instruction>(U.getUser())) |
946 | if (Seen.insert(UsrI->getFunction()).second) |
947 | Worklist.push_back(UsrI->getFunction()); |
948 | }); |
949 | } |
950 | } |
951 | |
952 | /// The slice of the module we are allowed to look at. |
953 | SmallPtrSet<Function *, 8> ModuleSlice; |
954 | |
955 | /// A vector type to hold instructions. |
956 | using InstructionVectorTy = SmallVector<Instruction *, 8>; |
957 | |
958 | /// A map type from opcodes to instructions with this opcode. |
959 | using OpcodeInstMapTy = DenseMap<unsigned, InstructionVectorTy *>; |
960 | |
961 | /// Return the map that relates "interesting" opcodes with all instructions |
962 | /// with that opcode in \p F. |
963 | OpcodeInstMapTy &getOpcodeInstMapForFunction(const Function &F) { |
964 | return getFunctionInfo(F).OpcodeInstMap; |
965 | } |
966 | |
967 | /// Return the instructions in \p F that may read or write memory. |
968 | InstructionVectorTy &getReadOrWriteInstsForFunction(const Function &F) { |
969 | return getFunctionInfo(F).RWInsts; |
970 | } |
971 | |
972 | /// Return MustBeExecutedContextExplorer |
973 | MustBeExecutedContextExplorer &getMustBeExecutedContextExplorer() { |
974 | return Explorer; |
975 | } |
976 | |
977 | /// Return TargetLibraryInfo for function \p F. |
978 | TargetLibraryInfo *getTargetLibraryInfoForFunction(const Function &F) { |
979 | return AG.getAnalysis<TargetLibraryAnalysis>(F); |
980 | } |
981 | |
982 | /// Return AliasAnalysis Result for function \p F. |
983 | AAResults *getAAResultsForFunction(const Function &F); |
984 | |
985 | /// Return true if \p Arg is involved in a must-tail call, thus the argument |
986 | /// of the caller or callee. |
987 | bool isInvolvedInMustTailCall(const Argument &Arg) { |
988 | FunctionInfo &FI = getFunctionInfo(*Arg.getParent()); |
989 | return FI.CalledViaMustTail || FI.ContainsMustTailCall; |
990 | } |
991 | |
992 | /// Return the analysis result from a pass \p AP for function \p F. |
993 | template <typename AP> |
994 | typename AP::Result *getAnalysisResultForFunction(const Function &F) { |
995 | return AG.getAnalysis<AP>(F); |
996 | } |
997 | |
998 | /// Return SCC size on call graph for function \p F or 0 if unknown. |
999 | unsigned getSccSize(const Function &F) { |
1000 | if (CGSCC && CGSCC->count(const_cast<Function *>(&F))) |
1001 | return CGSCC->size(); |
1002 | return 0; |
1003 | } |
1004 | |
1005 | /// Return datalayout used in the module. |
1006 | const DataLayout &getDL() { return DL; } |
1007 | |
1008 | /// Return the map conaining all the knowledge we have from `llvm.assume`s. |
1009 | const RetainedKnowledgeMap &getKnowledgeMap() const { return KnowledgeMap; } |
1010 | |
1011 | /// Return if \p To is potentially reachable form \p From or not |
1012 | /// If the same query was answered, return cached result |
1013 | bool getPotentiallyReachable(const Instruction &From, const Instruction &To) { |
1014 | auto KeyPair = std::make_pair(&From, &To); |
1015 | auto Iter = PotentiallyReachableMap.find(KeyPair); |
1016 | if (Iter != PotentiallyReachableMap.end()) |
1017 | return Iter->second; |
1018 | const Function &F = *From.getFunction(); |
1019 | bool Result = true; |
1020 | if (From.getFunction() == To.getFunction()) |
1021 | Result = isPotentiallyReachable(&From, &To, nullptr, |
1022 | AG.getAnalysis<DominatorTreeAnalysis>(F), |
1023 | AG.getAnalysis<LoopAnalysis>(F)); |
1024 | PotentiallyReachableMap.insert(std::make_pair(KeyPair, Result)); |
1025 | return Result; |
1026 | } |
1027 | |
1028 | /// Check whether \p F is part of module slice. |
1029 | bool isInModuleSlice(const Function &F) { |
1030 | return ModuleSlice.count(const_cast<Function *>(&F)); |
1031 | } |
1032 | |
1033 | /// Return true if the stack (llvm::Alloca) can be accessed by other threads. |
1034 | bool stackIsAccessibleByOtherThreads() { return !targetIsGPU(); } |
1035 | |
1036 | /// Return true if the target is a GPU. |
1037 | bool targetIsGPU() { |
1038 | return TargetTriple.isAMDGPU() || TargetTriple.isNVPTX(); |
1039 | } |
1040 | |
1041 | private: |
1042 | struct FunctionInfo { |
1043 | ~FunctionInfo(); |
1044 | |
1045 | /// A nested map that remembers all instructions in a function with a |
1046 | /// certain instruction opcode (Instruction::getOpcode()). |
1047 | OpcodeInstMapTy OpcodeInstMap; |
1048 | |
1049 | /// A map from functions to their instructions that may read or write |
1050 | /// memory. |
1051 | InstructionVectorTy RWInsts; |
1052 | |
1053 | /// Function is called by a `musttail` call. |
1054 | bool CalledViaMustTail; |
1055 | |
1056 | /// Function contains a `musttail` call. |
1057 | bool ContainsMustTailCall; |
1058 | }; |
1059 | |
1060 | /// A map type from functions to informatio about it. |
1061 | DenseMap<const Function *, FunctionInfo *> FuncInfoMap; |
1062 | |
1063 | /// Return information about the function \p F, potentially by creating it. |
1064 | FunctionInfo &getFunctionInfo(const Function &F) { |
1065 | FunctionInfo *&FI = FuncInfoMap[&F]; |
1066 | if (!FI) { |
1067 | FI = new (Allocator) FunctionInfo(); |
1068 | initializeInformationCache(F, *FI); |
1069 | } |
1070 | return *FI; |
1071 | } |
1072 | |
1073 | /// Initialize the function information cache \p FI for the function \p F. |
1074 | /// |
1075 | /// This method needs to be called for all function that might be looked at |
1076 | /// through the information cache interface *prior* to looking at them. |
1077 | void initializeInformationCache(const Function &F, FunctionInfo &FI); |
1078 | |
1079 | /// The datalayout used in the module. |
1080 | const DataLayout &DL; |
1081 | |
1082 | /// The allocator used to allocate memory, e.g. for `FunctionInfo`s. |
1083 | BumpPtrAllocator &Allocator; |
1084 | |
1085 | /// MustBeExecutedContextExplorer |
1086 | MustBeExecutedContextExplorer Explorer; |
1087 | |
1088 | /// A map with knowledge retained in `llvm.assume` instructions. |
1089 | RetainedKnowledgeMap KnowledgeMap; |
1090 | |
1091 | /// Getters for analysis. |
1092 | AnalysisGetter &AG; |
1093 | |
1094 | /// The underlying CGSCC, or null if not available. |
1095 | SetVector<Function *> *CGSCC; |
1096 | |
1097 | /// Set of inlineable functions |
1098 | SmallPtrSet<const Function *, 8> InlineableFunctions; |
1099 | |
1100 | /// A map for caching results of queries for isPotentiallyReachable |
1101 | DenseMap<std::pair<const Instruction *, const Instruction *>, bool> |
1102 | PotentiallyReachableMap; |
1103 | |
1104 | /// The triple describing the target machine. |
1105 | Triple TargetTriple; |
1106 | |
1107 | /// Give the Attributor access to the members so |
1108 | /// Attributor::identifyDefaultAbstractAttributes(...) can initialize them. |
1109 | friend struct Attributor; |
1110 | }; |
1111 | |
1112 | /// The fixpoint analysis framework that orchestrates the attribute deduction. |
1113 | /// |
1114 | /// The Attributor provides a general abstract analysis framework (guided |
1115 | /// fixpoint iteration) as well as helper functions for the deduction of |
1116 | /// (LLVM-IR) attributes. However, also other code properties can be deduced, |
1117 | /// propagated, and ultimately manifested through the Attributor framework. This |
1118 | /// is particularly useful if these properties interact with attributes and a |
1119 | /// co-scheduled deduction allows to improve the solution. Even if not, thus if |
1120 | /// attributes/properties are completely isolated, they should use the |
1121 | /// Attributor framework to reduce the number of fixpoint iteration frameworks |
1122 | /// in the code base. Note that the Attributor design makes sure that isolated |
1123 | /// attributes are not impacted, in any way, by others derived at the same time |
1124 | /// if there is no cross-reasoning performed. |
1125 | /// |
1126 | /// The public facing interface of the Attributor is kept simple and basically |
1127 | /// allows abstract attributes to one thing, query abstract attributes |
1128 | /// in-flight. There are two reasons to do this: |
1129 | /// a) The optimistic state of one abstract attribute can justify an |
1130 | /// optimistic state of another, allowing to framework to end up with an |
1131 | /// optimistic (=best possible) fixpoint instead of one based solely on |
1132 | /// information in the IR. |
1133 | /// b) This avoids reimplementing various kinds of lookups, e.g., to check |
1134 | /// for existing IR attributes, in favor of a single lookups interface |
1135 | /// provided by an abstract attribute subclass. |
1136 | /// |
1137 | /// NOTE: The mechanics of adding a new "concrete" abstract attribute are |
1138 | /// described in the file comment. |
1139 | struct Attributor { |
1140 | |
1141 | using OptimizationRemarkGetter = |
1142 | function_ref<OptimizationRemarkEmitter &(Function *)>; |
1143 | |
1144 | /// Constructor |
1145 | /// |
1146 | /// \param Functions The set of functions we are deriving attributes for. |
1147 | /// \param InfoCache Cache to hold various information accessible for |
1148 | /// the abstract attributes. |
1149 | /// \param CGUpdater Helper to update an underlying call graph. |
1150 | /// \param Allowed If not null, a set limiting the attribute opportunities. |
1151 | /// \param DeleteFns Whether to delete functions. |
1152 | /// \param RewriteSignatures Whether to rewrite function signatures. |
1153 | /// \param MaxFixedPointIterations Maximum number of iterations to run until |
1154 | /// fixpoint. |
1155 | Attributor(SetVector<Function *> &Functions, InformationCache &InfoCache, |
1156 | CallGraphUpdater &CGUpdater, |
1157 | DenseSet<const char *> *Allowed = nullptr, bool DeleteFns = true, |
1158 | bool RewriteSignatures = true) |
1159 | : Allocator(InfoCache.Allocator), Functions(Functions), |
1160 | InfoCache(InfoCache), CGUpdater(CGUpdater), Allowed(Allowed), |
1161 | DeleteFns(DeleteFns), RewriteSignatures(RewriteSignatures), |
1162 | MaxFixpointIterations(None), OREGetter(None), PassName("") {} |
1163 | |
1164 | /// Constructor |
1165 | /// |
1166 | /// \param Functions The set of functions we are deriving attributes for. |
1167 | /// \param InfoCache Cache to hold various information accessible for |
1168 | /// the abstract attributes. |
1169 | /// \param CGUpdater Helper to update an underlying call graph. |
1170 | /// \param Allowed If not null, a set limiting the attribute opportunities. |
1171 | /// \param DeleteFns Whether to delete functions |
1172 | /// \param MaxFixedPointIterations Maximum number of iterations to run until |
1173 | /// fixpoint. |
1174 | /// \param OREGetter A callback function that returns an ORE object from a |
1175 | /// Function pointer. |
1176 | /// \param PassName The name of the pass emitting remarks. |
1177 | Attributor(SetVector<Function *> &Functions, InformationCache &InfoCache, |
1178 | CallGraphUpdater &CGUpdater, DenseSet<const char *> *Allowed, |
1179 | bool DeleteFns, bool RewriteSignatures, |
1180 | Optional<unsigned> MaxFixpointIterations, |
1181 | OptimizationRemarkGetter OREGetter, const char *PassName) |
1182 | : Allocator(InfoCache.Allocator), Functions(Functions), |
1183 | InfoCache(InfoCache), CGUpdater(CGUpdater), Allowed(Allowed), |
1184 | DeleteFns(DeleteFns), RewriteSignatures(RewriteSignatures), |
1185 | MaxFixpointIterations(MaxFixpointIterations), |
1186 | OREGetter(Optional<OptimizationRemarkGetter>(OREGetter)), |
1187 | PassName(PassName) {} |
1188 | |
1189 | ~Attributor(); |
1190 | |
1191 | /// Run the analyses until a fixpoint is reached or enforced (timeout). |
1192 | /// |
1193 | /// The attributes registered with this Attributor can be used after as long |
1194 | /// as the Attributor is not destroyed (it owns the attributes now). |
1195 | /// |
1196 | /// \Returns CHANGED if the IR was changed, otherwise UNCHANGED. |
1197 | ChangeStatus run(); |
1198 | |
1199 | /// Lookup an abstract attribute of type \p AAType at position \p IRP. While |
1200 | /// no abstract attribute is found equivalent positions are checked, see |
1201 | /// SubsumingPositionIterator. Thus, the returned abstract attribute |
1202 | /// might be anchored at a different position, e.g., the callee if \p IRP is a |
1203 | /// call base. |
1204 | /// |
1205 | /// This method is the only (supported) way an abstract attribute can retrieve |
1206 | /// information from another abstract attribute. As an example, take an |
1207 | /// abstract attribute that determines the memory access behavior for a |
1208 | /// argument (readnone, readonly, ...). It should use `getAAFor` to get the |
1209 | /// most optimistic information for other abstract attributes in-flight, e.g. |
1210 | /// the one reasoning about the "captured" state for the argument or the one |
1211 | /// reasoning on the memory access behavior of the function as a whole. |
1212 | /// |
1213 | /// If the DepClass enum is set to `DepClassTy::None` the dependence from |
1214 | /// \p QueryingAA to the return abstract attribute is not automatically |
1215 | /// recorded. This should only be used if the caller will record the |
1216 | /// dependence explicitly if necessary, thus if it the returned abstract |
1217 | /// attribute is used for reasoning. To record the dependences explicitly use |
1218 | /// the `Attributor::recordDependence` method. |
1219 | template <typename AAType> |
1220 | const AAType &getAAFor(const AbstractAttribute &QueryingAA, |
1221 | const IRPosition &IRP, DepClassTy DepClass) { |
1222 | return getOrCreateAAFor<AAType>(IRP, &QueryingAA, DepClass, |
1223 | /* ForceUpdate */ false); |
1224 | } |
1225 | |
1226 | /// Similar to getAAFor but the return abstract attribute will be updated (via |
1227 | /// `AbstractAttribute::update`) even if it is found in the cache. This is |
1228 | /// especially useful for AAIsDead as changes in liveness can make updates |
1229 | /// possible/useful that were not happening before as the abstract attribute |
1230 | /// was assumed dead. |
1231 | template <typename AAType> |
1232 | const AAType &getAndUpdateAAFor(const AbstractAttribute &QueryingAA, |
1233 | const IRPosition &IRP, DepClassTy DepClass) { |
1234 | return getOrCreateAAFor<AAType>(IRP, &QueryingAA, DepClass, |
1235 | /* ForceUpdate */ true); |
1236 | } |
1237 | |
1238 | /// The version of getAAFor that allows to omit a querying abstract |
1239 | /// attribute. Using this after Attributor started running is restricted to |
1240 | /// only the Attributor itself. Initial seeding of AAs can be done via this |
1241 | /// function. |
1242 | /// NOTE: ForceUpdate is ignored in any stage other than the update stage. |
1243 | template <typename AAType> |
1244 | const AAType &getOrCreateAAFor(IRPosition IRP, |
1245 | const AbstractAttribute *QueryingAA, |
1246 | DepClassTy DepClass, bool ForceUpdate = false, |
1247 | bool UpdateAfterInit = true) { |
1248 | if (!shouldPropagateCallBaseContext(IRP)) |
1249 | IRP = IRP.stripCallBaseContext(); |
1250 | |
1251 | if (AAType *AAPtr = lookupAAFor<AAType>(IRP, QueryingAA, DepClass, |
1252 | /* AllowInvalidState */ true)) { |
1253 | if (ForceUpdate && Phase == AttributorPhase::UPDATE) |
1254 | updateAA(*AAPtr); |
1255 | return *AAPtr; |
1256 | } |
1257 | |
1258 | // No matching attribute found, create one. |
1259 | // Use the static create method. |
1260 | auto &AA = AAType::createForPosition(IRP, *this); |
1261 | |
1262 | // If we are currenty seeding attributes, enforce seeding rules. |
1263 | if (Phase == AttributorPhase::SEEDING && !shouldSeedAttribute(AA)) { |
1264 | AA.getState().indicatePessimisticFixpoint(); |
1265 | return AA; |
1266 | } |
1267 | |
1268 | registerAA(AA); |
1269 | |
1270 | // For now we ignore naked and optnone functions. |
1271 | bool Invalidate = Allowed && !Allowed->count(&AAType::ID); |
1272 | const Function *FnScope = IRP.getAnchorScope(); |
1273 | if (FnScope) |
1274 | Invalidate |= FnScope->hasFnAttribute(Attribute::Naked) || |
1275 | FnScope->hasFnAttribute(Attribute::OptimizeNone); |
1276 | |
1277 | // Avoid too many nested initializations to prevent a stack overflow. |
1278 | Invalidate |= InitializationChainLength > MaxInitializationChainLength; |
1279 | |
1280 | // Bootstrap the new attribute with an initial update to propagate |
1281 | // information, e.g., function -> call site. If it is not on a given |
1282 | // Allowed we will not perform updates at all. |
1283 | if (Invalidate) { |
1284 | AA.getState().indicatePessimisticFixpoint(); |
1285 | return AA; |
1286 | } |
1287 | |
1288 | { |
1289 | TimeTraceScope TimeScope(AA.getName() + "::initialize"); |
1290 | ++InitializationChainLength; |
1291 | AA.initialize(*this); |
1292 | --InitializationChainLength; |
1293 | } |
1294 | |
1295 | // Initialize and update is allowed for code outside of the current function |
1296 | // set, but only if it is part of module slice we are allowed to look at. |
1297 | // Only exception is AAIsDeadFunction whose initialization is prevented |
1298 | // directly, since we don't to compute it twice. |
1299 | if (FnScope && !Functions.count(const_cast<Function *>(FnScope))) { |
1300 | if (!getInfoCache().isInModuleSlice(*FnScope)) { |
1301 | AA.getState().indicatePessimisticFixpoint(); |
1302 | return AA; |
1303 | } |
1304 | } |
1305 | |
1306 | // If this is queried in the manifest stage, we force the AA to indicate |
1307 | // pessimistic fixpoint immediately. |
1308 | if (Phase == AttributorPhase::MANIFEST) { |
1309 | AA.getState().indicatePessimisticFixpoint(); |
1310 | return AA; |
1311 | } |
1312 | |
1313 | // Allow seeded attributes to declare dependencies. |
1314 | // Remember the seeding state. |
1315 | if (UpdateAfterInit) { |
1316 | AttributorPhase OldPhase = Phase; |
1317 | Phase = AttributorPhase::UPDATE; |
1318 | |
1319 | updateAA(AA); |
1320 | |
1321 | Phase = OldPhase; |
1322 | } |
1323 | |
1324 | if (QueryingAA && AA.getState().isValidState()) |
1325 | recordDependence(AA, const_cast<AbstractAttribute &>(*QueryingAA), |
1326 | DepClass); |
1327 | return AA; |
1328 | } |
1329 | template <typename AAType> |
1330 | const AAType &getOrCreateAAFor(const IRPosition &IRP) { |
1331 | return getOrCreateAAFor<AAType>(IRP, /* QueryingAA */ nullptr, |
1332 | DepClassTy::NONE); |
1333 | } |
1334 | |
1335 | /// Return the attribute of \p AAType for \p IRP if existing and valid. This |
1336 | /// also allows non-AA users lookup. |
1337 | template <typename AAType> |
1338 | AAType *lookupAAFor(const IRPosition &IRP, |
1339 | const AbstractAttribute *QueryingAA = nullptr, |
1340 | DepClassTy DepClass = DepClassTy::OPTIONAL, |
1341 | bool AllowInvalidState = false) { |
1342 | static_assert(std::is_base_of<AbstractAttribute, AAType>::value, |
1343 | "Cannot query an attribute with a type not derived from " |
1344 | "'AbstractAttribute'!"); |
1345 | // Lookup the abstract attribute of type AAType. If found, return it after |
1346 | // registering a dependence of QueryingAA on the one returned attribute. |
1347 | AbstractAttribute *AAPtr = AAMap.lookup({&AAType::ID, IRP}); |
1348 | if (!AAPtr) |
1349 | return nullptr; |
1350 | |
1351 | AAType *AA = static_cast<AAType *>(AAPtr); |
1352 | |
1353 | // Do not register a dependence on an attribute with an invalid state. |
1354 | if (DepClass != DepClassTy::NONE && QueryingAA && |
1355 | AA->getState().isValidState()) |
1356 | recordDependence(*AA, const_cast<AbstractAttribute &>(*QueryingAA), |
1357 | DepClass); |
1358 | |
1359 | // Return nullptr if this attribute has an invalid state. |
1360 | if (!AllowInvalidState && !AA->getState().isValidState()) |
1361 | return nullptr; |
1362 | return AA; |
1363 | } |
1364 | |
1365 | /// Explicitly record a dependence from \p FromAA to \p ToAA, that is if |
1366 | /// \p FromAA changes \p ToAA should be updated as well. |
1367 | /// |
1368 | /// This method should be used in conjunction with the `getAAFor` method and |
1369 | /// with the DepClass enum passed to the method set to None. This can |
1370 | /// be beneficial to avoid false dependences but it requires the users of |
1371 | /// `getAAFor` to explicitly record true dependences through this method. |
1372 | /// The \p DepClass flag indicates if the dependence is striclty necessary. |
1373 | /// That means for required dependences, if \p FromAA changes to an invalid |
1374 | /// state, \p ToAA can be moved to a pessimistic fixpoint because it required |
1375 | /// information from \p FromAA but none are available anymore. |
1376 | void recordDependence(const AbstractAttribute &FromAA, |
1377 | const AbstractAttribute &ToAA, DepClassTy DepClass); |
1378 | |
1379 | /// Introduce a new abstract attribute into the fixpoint analysis. |
1380 | /// |
1381 | /// Note that ownership of the attribute is given to the Attributor. It will |
1382 | /// invoke delete for the Attributor on destruction of the Attributor. |
1383 | /// |
1384 | /// Attributes are identified by their IR position (AAType::getIRPosition()) |
1385 | /// and the address of their static member (see AAType::ID). |
1386 | template <typename AAType> AAType ®isterAA(AAType &AA) { |
1387 | static_assert(std::is_base_of<AbstractAttribute, AAType>::value, |
1388 | "Cannot register an attribute with a type not derived from " |
1389 | "'AbstractAttribute'!"); |
1390 | // Put the attribute in the lookup map structure and the container we use to |
1391 | // keep track of all attributes. |
1392 | const IRPosition &IRP = AA.getIRPosition(); |
1393 | AbstractAttribute *&AAPtr = AAMap[{&AAType::ID, IRP}]; |
1394 | |
1395 | assert(!AAPtr && "Attribute already in map!")((void)0); |
1396 | AAPtr = &AA; |
1397 | |
1398 | // Register AA with the synthetic root only before the manifest stage. |
1399 | if (Phase == AttributorPhase::SEEDING || Phase == AttributorPhase::UPDATE) |
1400 | DG.SyntheticRoot.Deps.push_back( |
1401 | AADepGraphNode::DepTy(&AA, unsigned(DepClassTy::REQUIRED))); |
1402 | |
1403 | return AA; |
1404 | } |
1405 | |
1406 | /// Return the internal information cache. |
1407 | InformationCache &getInfoCache() { return InfoCache; } |
1408 | |
1409 | /// Return true if this is a module pass, false otherwise. |
1410 | bool isModulePass() const { |
1411 | return !Functions.empty() && |
1412 | Functions.size() == Functions.front()->getParent()->size(); |
1413 | } |
1414 | |
1415 | /// Return true if we derive attributes for \p Fn |
1416 | bool isRunOn(Function &Fn) const { |
1417 | return Functions.empty() || Functions.count(&Fn); |
1418 | } |
1419 | |
1420 | /// Determine opportunities to derive 'default' attributes in \p F and create |
1421 | /// abstract attribute objects for them. |
1422 | /// |
1423 | /// \param F The function that is checked for attribute opportunities. |
1424 | /// |
1425 | /// Note that abstract attribute instances are generally created even if the |
1426 | /// IR already contains the information they would deduce. The most important |
1427 | /// reason for this is the single interface, the one of the abstract attribute |
1428 | /// instance, which can be queried without the need to look at the IR in |
1429 | /// various places. |
1430 | void identifyDefaultAbstractAttributes(Function &F); |
1431 | |
1432 | /// Determine whether the function \p F is IPO amendable |
1433 | /// |
1434 | /// If a function is exactly defined or it has alwaysinline attribute |
1435 | /// and is viable to be inlined, we say it is IPO amendable |
1436 | bool isFunctionIPOAmendable(const Function &F) { |
1437 | return F.hasExactDefinition() || InfoCache.InlineableFunctions.count(&F); |
1438 | } |
1439 | |
1440 | /// Mark the internal function \p F as live. |
1441 | /// |
1442 | /// This will trigger the identification and initialization of attributes for |
1443 | /// \p F. |
1444 | void markLiveInternalFunction(const Function &F) { |
1445 | assert(F.hasLocalLinkage() &&((void)0) |
1446 | "Only local linkage is assumed dead initially.")((void)0); |
1447 | |
1448 | identifyDefaultAbstractAttributes(const_cast<Function &>(F)); |
1449 | } |
1450 | |
1451 | /// Helper function to remove callsite. |
1452 | void removeCallSite(CallInst *CI) { |
1453 | if (!CI) |
1454 | return; |
1455 | |
1456 | CGUpdater.removeCallSite(*CI); |
1457 | } |
1458 | |
1459 | /// Record that \p U is to be replaces with \p NV after information was |
1460 | /// manifested. This also triggers deletion of trivially dead istructions. |
1461 | bool changeUseAfterManifest(Use &U, Value &NV) { |
1462 | Value *&V = ToBeChangedUses[&U]; |
1463 | if (V && (V->stripPointerCasts() == NV.stripPointerCasts() || |
1464 | isa_and_nonnull<UndefValue>(V))) |
1465 | return false; |
1466 | assert((!V || V == &NV || isa<UndefValue>(NV)) &&((void)0) |
1467 | "Use was registered twice for replacement with different values!")((void)0); |
1468 | V = &NV; |
1469 | return true; |
1470 | } |
1471 | |
1472 | /// Helper function to replace all uses of \p V with \p NV. Return true if |
1473 | /// there is any change. The flag \p ChangeDroppable indicates if dropppable |
1474 | /// uses should be changed too. |
1475 | bool changeValueAfterManifest(Value &V, Value &NV, |
1476 | bool ChangeDroppable = true) { |
1477 | auto &Entry = ToBeChangedValues[&V]; |
1478 | Value *&CurNV = Entry.first; |
1479 | if (CurNV && (CurNV->stripPointerCasts() == NV.stripPointerCasts() || |
1480 | isa<UndefValue>(CurNV))) |
1481 | return false; |
1482 | assert((!CurNV || CurNV == &NV || isa<UndefValue>(NV)) &&((void)0) |
1483 | "Value replacement was registered twice with different values!")((void)0); |
1484 | CurNV = &NV; |
1485 | Entry.second = ChangeDroppable; |
1486 | return true; |
1487 | } |
1488 | |
1489 | /// Record that \p I is to be replaced with `unreachable` after information |
1490 | /// was manifested. |
1491 | void changeToUnreachableAfterManifest(Instruction *I) { |
1492 | ToBeChangedToUnreachableInsts.insert(I); |
1493 | } |
1494 | |
1495 | /// Record that \p II has at least one dead successor block. This information |
1496 | /// is used, e.g., to replace \p II with a call, after information was |
1497 | /// manifested. |
1498 | void registerInvokeWithDeadSuccessor(InvokeInst &II) { |
1499 | InvokeWithDeadSuccessor.push_back(&II); |
1500 | } |
1501 | |
1502 | /// Record that \p I is deleted after information was manifested. This also |
1503 | /// triggers deletion of trivially dead istructions. |
1504 | void deleteAfterManifest(Instruction &I) { ToBeDeletedInsts.insert(&I); } |
1505 | |
1506 | /// Record that \p BB is deleted after information was manifested. This also |
1507 | /// triggers deletion of trivially dead istructions. |
1508 | void deleteAfterManifest(BasicBlock &BB) { ToBeDeletedBlocks.insert(&BB); } |
1509 | |
1510 | // Record that \p BB is added during the manifest of an AA. Added basic blocks |
1511 | // are preserved in the IR. |
1512 | void registerManifestAddedBasicBlock(BasicBlock &BB) { |
1513 | ManifestAddedBlocks.insert(&BB); |
1514 | } |
1515 | |
1516 | /// Record that \p F is deleted after information was manifested. |
1517 | void deleteAfterManifest(Function &F) { |
1518 | if (DeleteFns) |
1519 | ToBeDeletedFunctions.insert(&F); |
1520 | } |
1521 | |
1522 | /// If \p IRP is assumed to be a constant, return it, if it is unclear yet, |
1523 | /// return None, otherwise return `nullptr`. |
1524 | Optional<Constant *> getAssumedConstant(const IRPosition &IRP, |
1525 | const AbstractAttribute &AA, |
1526 | bool &UsedAssumedInformation); |
1527 | Optional<Constant *> getAssumedConstant(const Value &V, |
1528 | const AbstractAttribute &AA, |
1529 | bool &UsedAssumedInformation) { |
1530 | return getAssumedConstant(IRPosition::value(V), AA, UsedAssumedInformation); |
1531 | } |
1532 | |
1533 | /// If \p V is assumed simplified, return it, if it is unclear yet, |
1534 | /// return None, otherwise return `nullptr`. |
1535 | Optional<Value *> getAssumedSimplified(const IRPosition &IRP, |
1536 | const AbstractAttribute &AA, |
1537 | bool &UsedAssumedInformation) { |
1538 | return getAssumedSimplified(IRP, &AA, UsedAssumedInformation); |
1539 | } |
1540 | Optional<Value *> getAssumedSimplified(const Value &V, |
1541 | const AbstractAttribute &AA, |
1542 | bool &UsedAssumedInformation) { |
1543 | return getAssumedSimplified(IRPosition::value(V), AA, |
1544 | UsedAssumedInformation); |
1545 | } |
1546 | |
1547 | /// If \p V is assumed simplified, return it, if it is unclear yet, |
1548 | /// return None, otherwise return `nullptr`. Same as the public version |
1549 | /// except that it can be used without recording dependences on any \p AA. |
1550 | Optional<Value *> getAssumedSimplified(const IRPosition &V, |
1551 | const AbstractAttribute *AA, |
1552 | bool &UsedAssumedInformation); |
1553 | |
1554 | /// Register \p CB as a simplification callback. |
1555 | /// `Attributor::getAssumedSimplified` will use these callbacks before |
1556 | /// we it will ask `AAValueSimplify`. It is important to ensure this |
1557 | /// is called before `identifyDefaultAbstractAttributes`, assuming the |
1558 | /// latter is called at all. |
1559 | using SimplifictionCallbackTy = std::function<Optional<Value *>( |
1560 | const IRPosition &, const AbstractAttribute *, bool &)>; |
1561 | void registerSimplificationCallback(const IRPosition &IRP, |
1562 | const SimplifictionCallbackTy &CB) { |
1563 | SimplificationCallbacks[IRP].emplace_back(CB); |
1564 | } |
1565 | |
1566 | /// Return true if there is a simplification callback for \p IRP. |
1567 | bool hasSimplificationCallback(const IRPosition &IRP) { |
1568 | return SimplificationCallbacks.count(IRP); |
1569 | } |
1570 | |
1571 | private: |
1572 | /// The vector with all simplification callbacks registered by outside AAs. |
1573 | DenseMap<IRPosition, SmallVector<SimplifictionCallbackTy, 1>> |
1574 | SimplificationCallbacks; |
1575 | |
1576 | public: |
1577 | /// Translate \p V from the callee context into the call site context. |
1578 | Optional<Value *> |
1579 | translateArgumentToCallSiteContent(Optional<Value *> V, CallBase &CB, |
1580 | const AbstractAttribute &AA, |
1581 | bool &UsedAssumedInformation); |
1582 | |
1583 | /// Return true if \p AA (or its context instruction) is assumed dead. |
1584 | /// |
1585 | /// If \p LivenessAA is not provided it is queried. |
1586 | bool isAssumedDead(const AbstractAttribute &AA, const AAIsDead *LivenessAA, |
1587 | bool &UsedAssumedInformation, |
1588 | bool CheckBBLivenessOnly = false, |
1589 | DepClassTy DepClass = DepClassTy::OPTIONAL); |
1590 | |
1591 | /// Return true if \p I is assumed dead. |
1592 | /// |
1593 | /// If \p LivenessAA is not provided it is queried. |
1594 | bool isAssumedDead(const Instruction &I, const AbstractAttribute *QueryingAA, |
1595 | const AAIsDead *LivenessAA, bool &UsedAssumedInformation, |
1596 | bool CheckBBLivenessOnly = false, |
1597 | DepClassTy DepClass = DepClassTy::OPTIONAL); |
1598 | |
1599 | /// Return true if \p U is assumed dead. |
1600 | /// |
1601 | /// If \p FnLivenessAA is not provided it is queried. |
1602 | bool isAssumedDead(const Use &U, const AbstractAttribute *QueryingAA, |
1603 | const AAIsDead *FnLivenessAA, bool &UsedAssumedInformation, |
1604 | bool CheckBBLivenessOnly = false, |
1605 | DepClassTy DepClass = DepClassTy::OPTIONAL); |
1606 | |
1607 | /// Return true if \p IRP is assumed dead. |
1608 | /// |
1609 | /// If \p FnLivenessAA is not provided it is queried. |
1610 | bool isAssumedDead(const IRPosition &IRP, const AbstractAttribute *QueryingAA, |
1611 | const AAIsDead *FnLivenessAA, bool &UsedAssumedInformation, |
1612 | bool CheckBBLivenessOnly = false, |
1613 | DepClassTy DepClass = DepClassTy::OPTIONAL); |
1614 | |
1615 | /// Return true if \p BB is assumed dead. |
1616 | /// |
1617 | /// If \p LivenessAA is not provided it is queried. |
1618 | bool isAssumedDead(const BasicBlock &BB, const AbstractAttribute *QueryingAA, |
1619 | const AAIsDead *FnLivenessAA, |
1620 | DepClassTy DepClass = DepClassTy::OPTIONAL); |
1621 | |
1622 | /// Check \p Pred on all (transitive) uses of \p V. |
1623 | /// |
1624 | /// This method will evaluate \p Pred on all (transitive) uses of the |
1625 | /// associated value and return true if \p Pred holds every time. |
1626 | bool checkForAllUses(function_ref<bool(const Use &, bool &)> Pred, |
1627 | const AbstractAttribute &QueryingAA, const Value &V, |
1628 | bool CheckBBLivenessOnly = false, |
1629 | DepClassTy LivenessDepClass = DepClassTy::OPTIONAL); |
1630 | |
1631 | /// Emit a remark generically. |
1632 | /// |
1633 | /// This template function can be used to generically emit a remark. The |
1634 | /// RemarkKind should be one of the following: |
1635 | /// - OptimizationRemark to indicate a successful optimization attempt |
1636 | /// - OptimizationRemarkMissed to report a failed optimization attempt |
1637 | /// - OptimizationRemarkAnalysis to provide additional information about an |
1638 | /// optimization attempt |
1639 | /// |
1640 | /// The remark is built using a callback function \p RemarkCB that takes a |
1641 | /// RemarkKind as input and returns a RemarkKind. |
1642 | template <typename RemarkKind, typename RemarkCallBack> |
1643 | void emitRemark(Instruction *I, StringRef RemarkName, |
1644 | RemarkCallBack &&RemarkCB) const { |
1645 | if (!OREGetter) |
1646 | return; |
1647 | |
1648 | Function *F = I->getFunction(); |
1649 | auto &ORE = OREGetter.getValue()(F); |
1650 | |
1651 | if (RemarkName.startswith("OMP")) |
1652 | ORE.emit([&]() { |
1653 | return RemarkCB(RemarkKind(PassName, RemarkName, I)) |
1654 | << " [" << RemarkName << "]"; |
1655 | }); |
1656 | else |
1657 | ORE.emit([&]() { return RemarkCB(RemarkKind(PassName, RemarkName, I)); }); |
1658 | } |
1659 | |
1660 | /// Emit a remark on a function. |
1661 | template <typename RemarkKind, typename RemarkCallBack> |
1662 | void emitRemark(Function *F, StringRef RemarkName, |
1663 | RemarkCallBack &&RemarkCB) const { |
1664 | if (!OREGetter) |
1665 | return; |
1666 | |
1667 | auto &ORE = OREGetter.getValue()(F); |
1668 | |
1669 | if (RemarkName.startswith("OMP")) |
1670 | ORE.emit([&]() { |
1671 | return RemarkCB(RemarkKind(PassName, RemarkName, F)) |
1672 | << " [" << RemarkName << "]"; |
1673 | }); |
1674 | else |
1675 | ORE.emit([&]() { return RemarkCB(RemarkKind(PassName, RemarkName, F)); }); |
1676 | } |
1677 | |
1678 | /// Helper struct used in the communication between an abstract attribute (AA) |
1679 | /// that wants to change the signature of a function and the Attributor which |
1680 | /// applies the changes. The struct is partially initialized with the |
1681 | /// information from the AA (see the constructor). All other members are |
1682 | /// provided by the Attributor prior to invoking any callbacks. |
1683 | struct ArgumentReplacementInfo { |
1684 | /// Callee repair callback type |
1685 | /// |
1686 | /// The function repair callback is invoked once to rewire the replacement |
1687 | /// arguments in the body of the new function. The argument replacement info |
1688 | /// is passed, as build from the registerFunctionSignatureRewrite call, as |
1689 | /// well as the replacement function and an iteratore to the first |
1690 | /// replacement argument. |
1691 | using CalleeRepairCBTy = std::function<void( |
1692 | const ArgumentReplacementInfo &, Function &, Function::arg_iterator)>; |
1693 | |
1694 | /// Abstract call site (ACS) repair callback type |
1695 | /// |
1696 | /// The abstract call site repair callback is invoked once on every abstract |
1697 | /// call site of the replaced function (\see ReplacedFn). The callback needs |
1698 | /// to provide the operands for the call to the new replacement function. |
1699 | /// The number and type of the operands appended to the provided vector |
1700 | /// (second argument) is defined by the number and types determined through |
1701 | /// the replacement type vector (\see ReplacementTypes). The first argument |
1702 | /// is the ArgumentReplacementInfo object registered with the Attributor |
1703 | /// through the registerFunctionSignatureRewrite call. |
1704 | using ACSRepairCBTy = |
1705 | std::function<void(const ArgumentReplacementInfo &, AbstractCallSite, |
1706 | SmallVectorImpl<Value *> &)>; |
1707 | |
1708 | /// Simple getters, see the corresponding members for details. |
1709 | ///{ |
1710 | |
1711 | Attributor &getAttributor() const { return A; } |
1712 | const Function &getReplacedFn() const { return ReplacedFn; } |
1713 | const Argument &getReplacedArg() const { return ReplacedArg; } |
1714 | unsigned getNumReplacementArgs() const { return ReplacementTypes.size(); } |
1715 | const SmallVectorImpl<Type *> &getReplacementTypes() const { |
1716 | return ReplacementTypes; |
1717 | } |
1718 | |
1719 | ///} |
1720 | |
1721 | private: |
1722 | /// Constructor that takes the argument to be replaced, the types of |
1723 | /// the replacement arguments, as well as callbacks to repair the call sites |
1724 | /// and new function after the replacement happened. |
1725 | ArgumentReplacementInfo(Attributor &A, Argument &Arg, |
1726 | ArrayRef<Type *> ReplacementTypes, |
1727 | CalleeRepairCBTy &&CalleeRepairCB, |
1728 | ACSRepairCBTy &&ACSRepairCB) |
1729 | : A(A), ReplacedFn(*Arg.getParent()), ReplacedArg(Arg), |
1730 | ReplacementTypes(ReplacementTypes.begin(), ReplacementTypes.end()), |
1731 | CalleeRepairCB(std::move(CalleeRepairCB)), |
1732 | ACSRepairCB(std::move(ACSRepairCB)) {} |
1733 | |
1734 | /// Reference to the attributor to allow access from the callbacks. |
1735 | Attributor &A; |
1736 | |
1737 | /// The "old" function replaced by ReplacementFn. |
1738 | const Function &ReplacedFn; |
1739 | |
1740 | /// The "old" argument replaced by new ones defined via ReplacementTypes. |
1741 | const Argument &ReplacedArg; |
1742 | |
1743 | /// The types of the arguments replacing ReplacedArg. |
1744 | const SmallVector<Type *, 8> ReplacementTypes; |
1745 | |
1746 | /// Callee repair callback, see CalleeRepairCBTy. |
1747 | const CalleeRepairCBTy CalleeRepairCB; |
1748 | |
1749 | /// Abstract call site (ACS) repair callback, see ACSRepairCBTy. |
1750 | const ACSRepairCBTy ACSRepairCB; |
1751 | |
1752 | /// Allow access to the private members from the Attributor. |
1753 | friend struct Attributor; |
1754 | }; |
1755 | |
1756 | /// Check if we can rewrite a function signature. |
1757 | /// |
1758 | /// The argument \p Arg is replaced with new ones defined by the number, |
1759 | /// order, and types in \p ReplacementTypes. |
1760 | /// |
1761 | /// \returns True, if the replacement can be registered, via |
1762 | /// registerFunctionSignatureRewrite, false otherwise. |
1763 | bool isValidFunctionSignatureRewrite(Argument &Arg, |
1764 | ArrayRef<Type *> ReplacementTypes); |
1765 | |
1766 | /// Register a rewrite for a function signature. |
1767 | /// |
1768 | /// The argument \p Arg is replaced with new ones defined by the number, |
1769 | /// order, and types in \p ReplacementTypes. The rewiring at the call sites is |
1770 | /// done through \p ACSRepairCB and at the callee site through |
1771 | /// \p CalleeRepairCB. |
1772 | /// |
1773 | /// \returns True, if the replacement was registered, false otherwise. |
1774 | bool registerFunctionSignatureRewrite( |
1775 | Argument &Arg, ArrayRef<Type *> ReplacementTypes, |
1776 | ArgumentReplacementInfo::CalleeRepairCBTy &&CalleeRepairCB, |
1777 | ArgumentReplacementInfo::ACSRepairCBTy &&ACSRepairCB); |
1778 | |
1779 | /// Check \p Pred on all function call sites. |
1780 | /// |
1781 | /// This method will evaluate \p Pred on call sites and return |
1782 | /// true if \p Pred holds in every call sites. However, this is only possible |
1783 | /// all call sites are known, hence the function has internal linkage. |
1784 | /// If true is returned, \p AllCallSitesKnown is set if all possible call |
1785 | /// sites of the function have been visited. |
1786 | bool checkForAllCallSites(function_ref<bool(AbstractCallSite)> Pred, |
1787 | const AbstractAttribute &QueryingAA, |
1788 | bool RequireAllCallSites, bool &AllCallSitesKnown); |
1789 | |
1790 | /// Check \p Pred on all values potentially returned by \p F. |
1791 | /// |
1792 | /// This method will evaluate \p Pred on all values potentially returned by |
1793 | /// the function associated with \p QueryingAA. The returned values are |
1794 | /// matched with their respective return instructions. Returns true if \p Pred |
1795 | /// holds on all of them. |
1796 | bool checkForAllReturnedValuesAndReturnInsts( |
1797 | function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred, |
1798 | const AbstractAttribute &QueryingAA); |
1799 | |
1800 | /// Check \p Pred on all values potentially returned by the function |
1801 | /// associated with \p QueryingAA. |
1802 | /// |
1803 | /// This is the context insensitive version of the method above. |
1804 | bool checkForAllReturnedValues(function_ref<bool(Value &)> Pred, |
1805 | const AbstractAttribute &QueryingAA); |
1806 | |
1807 | /// Check \p Pred on all instructions with an opcode present in \p Opcodes. |
1808 | /// |
1809 | /// This method will evaluate \p Pred on all instructions with an opcode |
1810 | /// present in \p Opcode and return true if \p Pred holds on all of them. |
1811 | bool checkForAllInstructions(function_ref<bool(Instruction &)> Pred, |
1812 | const AbstractAttribute &QueryingAA, |
1813 | const ArrayRef<unsigned> &Opcodes, |
1814 | bool &UsedAssumedInformation, |
1815 | bool CheckBBLivenessOnly = false, |
1816 | bool CheckPotentiallyDead = false); |
1817 | |
1818 | /// Check \p Pred on all call-like instructions (=CallBased derived). |
1819 | /// |
1820 | /// See checkForAllCallLikeInstructions(...) for more information. |
1821 | bool checkForAllCallLikeInstructions(function_ref<bool(Instruction &)> Pred, |
1822 | const AbstractAttribute &QueryingAA, |
1823 | bool &UsedAssumedInformation, |
1824 | bool CheckBBLivenessOnly = false, |
1825 | bool CheckPotentiallyDead = false) { |
1826 | return checkForAllInstructions( |
1827 | Pred, QueryingAA, |
1828 | {(unsigned)Instruction::Invoke, (unsigned)Instruction::CallBr, |
1829 | (unsigned)Instruction::Call}, |
1830 | UsedAssumedInformation, CheckBBLivenessOnly, CheckPotentiallyDead); |
1831 | } |
1832 | |
1833 | /// Check \p Pred on all Read/Write instructions. |
1834 | /// |
1835 | /// This method will evaluate \p Pred on all instructions that read or write |
1836 | /// to memory present in the information cache and return true if \p Pred |
1837 | /// holds on all of them. |
1838 | bool checkForAllReadWriteInstructions(function_ref<bool(Instruction &)> Pred, |
1839 | AbstractAttribute &QueryingAA, |
1840 | bool &UsedAssumedInformation); |
1841 | |
1842 | /// Create a shallow wrapper for \p F such that \p F has internal linkage |
1843 | /// afterwards. It also sets the original \p F 's name to anonymous |
1844 | /// |
1845 | /// A wrapper is a function with the same type (and attributes) as \p F |
1846 | /// that will only call \p F and return the result, if any. |
1847 | /// |
1848 | /// Assuming the declaration of looks like: |
1849 | /// rty F(aty0 arg0, ..., atyN argN); |
1850 | /// |
1851 | /// The wrapper will then look as follows: |
1852 | /// rty wrapper(aty0 arg0, ..., atyN argN) { |
1853 | /// return F(arg0, ..., argN); |
1854 | /// } |
1855 | /// |
1856 | static void createShallowWrapper(Function &F); |
1857 | |
1858 | /// Returns true if the function \p F can be internalized. i.e. it has a |
1859 | /// compatible linkage. |
1860 | static bool isInternalizable(Function &F); |
1861 | |
1862 | /// Make another copy of the function \p F such that the copied version has |
1863 | /// internal linkage afterwards and can be analysed. Then we replace all uses |
1864 | /// of the original function to the copied one |
1865 | /// |
1866 | /// Only non-locally linked functions that have `linkonce_odr` or `weak_odr` |
1867 | /// linkage can be internalized because these linkages guarantee that other |
1868 | /// definitions with the same name have the same semantics as this one. |
1869 | /// |
1870 | /// This will only be run if the `attributor-allow-deep-wrappers` option is |
1871 | /// set, or if the function is called with \p Force set to true. |
1872 | /// |
1873 | /// If the function \p F failed to be internalized the return value will be a |
1874 | /// null pointer. |
1875 | static Function *internalizeFunction(Function &F, bool Force = false); |
1876 | |
1877 | /// Make copies of each function in the set \p FnSet such that the copied |
1878 | /// version has internal linkage afterwards and can be analysed. Then we |
1879 | /// replace all uses of the original function to the copied one. The map |
1880 | /// \p FnMap contains a mapping of functions to their internalized versions. |
1881 | /// |
1882 | /// Only non-locally linked functions that have `linkonce_odr` or `weak_odr` |
1883 | /// linkage can be internalized because these linkages guarantee that other |
1884 | /// definitions with the same name have the same semantics as this one. |
1885 | /// |
1886 | /// This version will internalize all the functions in the set \p FnSet at |
1887 | /// once and then replace the uses. This prevents internalized functions being |
1888 | /// called by external functions when there is an internalized version in the |
1889 | /// module. |
1890 | static bool internalizeFunctions(SmallPtrSetImpl<Function *> &FnSet, |
1891 | DenseMap<Function *, Function *> &FnMap); |
1892 | |
1893 | /// Return the data layout associated with the anchor scope. |
1894 | const DataLayout &getDataLayout() const { return InfoCache.DL; } |
1895 | |
1896 | /// The allocator used to allocate memory, e.g. for `AbstractAttribute`s. |
1897 | BumpPtrAllocator &Allocator; |
1898 | |
1899 | private: |
1900 | /// This method will do fixpoint iteration until fixpoint or the |
1901 | /// maximum iteration count is reached. |
1902 | /// |
1903 | /// If the maximum iteration count is reached, This method will |
1904 | /// indicate pessimistic fixpoint on attributes that transitively depend |
1905 | /// on attributes that were scheduled for an update. |
1906 | void runTillFixpoint(); |
1907 | |
1908 | /// Gets called after scheduling, manifests attributes to the LLVM IR. |
1909 | ChangeStatus manifestAttributes(); |
1910 | |
1911 | /// Gets called after attributes have been manifested, cleans up the IR. |
1912 | /// Deletes dead functions, blocks and instructions. |
1913 | /// Rewrites function signitures and updates the call graph. |
1914 | ChangeStatus cleanupIR(); |
1915 | |
1916 | /// Identify internal functions that are effectively dead, thus not reachable |
1917 | /// from a live entry point. The functions are added to ToBeDeletedFunctions. |
1918 | void identifyDeadInternalFunctions(); |
1919 | |
1920 | /// Run `::update` on \p AA and track the dependences queried while doing so. |
1921 | /// Also adjust the state if we know further updates are not necessary. |
1922 | ChangeStatus updateAA(AbstractAttribute &AA); |
1923 | |
1924 | /// Remember the dependences on the top of the dependence stack such that they |
1925 | /// may trigger further updates. (\see DependenceStack) |
1926 | void rememberDependences(); |
1927 | |
1928 | /// Check \p Pred on all call sites of \p Fn. |
1929 | /// |
1930 | /// This method will evaluate \p Pred on call sites and return |
1931 | /// true if \p Pred holds in every call sites. However, this is only possible |
1932 | /// all call sites are known, hence the function has internal linkage. |
1933 | /// If true is returned, \p AllCallSitesKnown is set if all possible call |
1934 | /// sites of the function have been visited. |
1935 | bool checkForAllCallSites(function_ref<bool(AbstractCallSite)> Pred, |
1936 | const Function &Fn, bool RequireAllCallSites, |
1937 | const AbstractAttribute *QueryingAA, |
1938 | bool &AllCallSitesKnown); |
1939 | |
1940 | /// Determine if CallBase context in \p IRP should be propagated. |
1941 | bool shouldPropagateCallBaseContext(const IRPosition &IRP); |
1942 | |
1943 | /// Apply all requested function signature rewrites |
1944 | /// (\see registerFunctionSignatureRewrite) and return Changed if the module |
1945 | /// was altered. |
1946 | ChangeStatus |
1947 | rewriteFunctionSignatures(SmallPtrSetImpl<Function *> &ModifiedFns); |
1948 | |
1949 | /// Check if the Attribute \p AA should be seeded. |
1950 | /// See getOrCreateAAFor. |
1951 | bool shouldSeedAttribute(AbstractAttribute &AA); |
1952 | |
1953 | /// A nested map to lookup abstract attributes based on the argument position |
1954 | /// on the outer level, and the addresses of the static member (AAType::ID) on |
1955 | /// the inner level. |
1956 | ///{ |
1957 | using AAMapKeyTy = std::pair<const char *, IRPosition>; |
1958 | DenseMap<AAMapKeyTy, AbstractAttribute *> AAMap; |
1959 | ///} |
1960 | |
1961 | /// Map to remember all requested signature changes (= argument replacements). |
1962 | DenseMap<Function *, SmallVector<std::unique_ptr<ArgumentReplacementInfo>, 8>> |
1963 | ArgumentReplacementMap; |
1964 | |
1965 | /// The set of functions we are deriving attributes for. |
1966 | SetVector<Function *> &Functions; |
1967 | |
1968 | /// The information cache that holds pre-processed (LLVM-IR) information. |
1969 | InformationCache &InfoCache; |
1970 | |
1971 | /// Helper to update an underlying call graph. |
1972 | CallGraphUpdater &CGUpdater; |
1973 | |
1974 | /// Abstract Attribute dependency graph |
1975 | AADepGraph DG; |
1976 | |
1977 | /// Set of functions for which we modified the content such that it might |
1978 | /// impact the call graph. |
1979 | SmallPtrSet<Function *, 8> CGModifiedFunctions; |
1980 | |
1981 | /// Information about a dependence. If FromAA is changed ToAA needs to be |
1982 | /// updated as well. |
1983 | struct DepInfo { |
1984 | const AbstractAttribute *FromAA; |
1985 | const AbstractAttribute *ToAA; |
1986 | DepClassTy DepClass; |
1987 | }; |
1988 | |
1989 | /// The dependence stack is used to track dependences during an |
1990 | /// `AbstractAttribute::update` call. As `AbstractAttribute::update` can be |
1991 | /// recursive we might have multiple vectors of dependences in here. The stack |
1992 | /// size, should be adjusted according to the expected recursion depth and the |
1993 | /// inner dependence vector size to the expected number of dependences per |
1994 | /// abstract attribute. Since the inner vectors are actually allocated on the |
1995 | /// stack we can be generous with their size. |
1996 | using DependenceVector = SmallVector<DepInfo, 8>; |
1997 | SmallVector<DependenceVector *, 16> DependenceStack; |
1998 | |
1999 | /// If not null, a set limiting the attribute opportunities. |
2000 | const DenseSet<const char *> *Allowed; |
2001 | |
2002 | /// Whether to delete functions. |
2003 | const bool DeleteFns; |
2004 | |
2005 | /// Whether to rewrite signatures. |
2006 | const bool RewriteSignatures; |
2007 | |
2008 | /// Maximum number of fixedpoint iterations. |
2009 | Optional<unsigned> MaxFixpointIterations; |
2010 | |
2011 | /// A set to remember the functions we already assume to be live and visited. |
2012 | DenseSet<const Function *> VisitedFunctions; |
2013 | |
2014 | /// Uses we replace with a new value after manifest is done. We will remove |
2015 | /// then trivially dead instructions as well. |
2016 | DenseMap<Use *, Value *> ToBeChangedUses; |
2017 | |
2018 | /// Values we replace with a new value after manifest is done. We will remove |
2019 | /// then trivially dead instructions as well. |
2020 | DenseMap<Value *, std::pair<Value *, bool>> ToBeChangedValues; |
2021 | |
2022 | /// Instructions we replace with `unreachable` insts after manifest is done. |
2023 | SmallDenseSet<WeakVH, 16> ToBeChangedToUnreachableInsts; |
2024 | |
2025 | /// Invoke instructions with at least a single dead successor block. |
2026 | SmallVector<WeakVH, 16> InvokeWithDeadSuccessor; |
2027 | |
2028 | /// A flag that indicates which stage of the process we are in. Initially, the |
2029 | /// phase is SEEDING. Phase is changed in `Attributor::run()` |
2030 | enum class AttributorPhase { |
2031 | SEEDING, |
2032 | UPDATE, |
2033 | MANIFEST, |
2034 | CLEANUP, |
2035 | } Phase = AttributorPhase::SEEDING; |
2036 | |
2037 | /// The current initialization chain length. Tracked to avoid stack overflows. |
2038 | unsigned InitializationChainLength = 0; |
2039 | |
2040 | /// Functions, blocks, and instructions we delete after manifest is done. |
2041 | /// |
2042 | ///{ |
2043 | SmallPtrSet<Function *, 8> ToBeDeletedFunctions; |
2044 | SmallPtrSet<BasicBlock *, 8> ToBeDeletedBlocks; |
2045 | SmallPtrSet<BasicBlock *, 8> ManifestAddedBlocks; |
2046 | SmallDenseSet<WeakVH, 8> ToBeDeletedInsts; |
2047 | ///} |
2048 | |
2049 | /// Callback to get an OptimizationRemarkEmitter from a Function *. |
2050 | Optional<OptimizationRemarkGetter> OREGetter; |
2051 | |
2052 | /// The name of the pass to emit remarks for. |
2053 | const char *PassName = ""; |
2054 | |
2055 | friend AADepGraph; |
2056 | friend AttributorCallGraph; |
2057 | }; |
2058 | |
2059 | /// An interface to query the internal state of an abstract attribute. |
2060 | /// |
2061 | /// The abstract state is a minimal interface that allows the Attributor to |
2062 | /// communicate with the abstract attributes about their internal state without |
2063 | /// enforcing or exposing implementation details, e.g., the (existence of an) |
2064 | /// underlying lattice. |
2065 | /// |
2066 | /// It is sufficient to be able to query if a state is (1) valid or invalid, (2) |
2067 | /// at a fixpoint, and to indicate to the state that (3) an optimistic fixpoint |
2068 | /// was reached or (4) a pessimistic fixpoint was enforced. |
2069 | /// |
2070 | /// All methods need to be implemented by the subclass. For the common use case, |
2071 | /// a single boolean state or a bit-encoded state, the BooleanState and |
2072 | /// {Inc,Dec,Bit}IntegerState classes are already provided. An abstract |
2073 | /// attribute can inherit from them to get the abstract state interface and |
2074 | /// additional methods to directly modify the state based if needed. See the |
2075 | /// class comments for help. |
2076 | struct AbstractState { |
2077 | virtual ~AbstractState() {} |
2078 | |
2079 | /// Return if this abstract state is in a valid state. If false, no |
2080 | /// information provided should be used. |
2081 | virtual bool isValidState() const = 0; |
2082 | |
2083 | /// Return if this abstract state is fixed, thus does not need to be updated |
2084 | /// if information changes as it cannot change itself. |
2085 | virtual bool isAtFixpoint() const = 0; |
2086 | |
2087 | /// Indicate that the abstract state should converge to the optimistic state. |
2088 | /// |
2089 | /// This will usually make the optimistically assumed state the known to be |
2090 | /// true state. |
2091 | /// |
2092 | /// \returns ChangeStatus::UNCHANGED as the assumed value should not change. |
2093 | virtual ChangeStatus indicateOptimisticFixpoint() = 0; |
2094 | |
2095 | /// Indicate that the abstract state should converge to the pessimistic state. |
2096 | /// |
2097 | /// This will usually revert the optimistically assumed state to the known to |
2098 | /// be true state. |
2099 | /// |
2100 | /// \returns ChangeStatus::CHANGED as the assumed value may change. |
2101 | virtual ChangeStatus indicatePessimisticFixpoint() = 0; |
2102 | }; |
2103 | |
2104 | /// Simple state with integers encoding. |
2105 | /// |
2106 | /// The interface ensures that the assumed bits are always a subset of the known |
2107 | /// bits. Users can only add known bits and, except through adding known bits, |
2108 | /// they can only remove assumed bits. This should guarantee monotoniticy and |
2109 | /// thereby the existence of a fixpoint (if used corretly). The fixpoint is |
2110 | /// reached when the assumed and known state/bits are equal. Users can |
2111 | /// force/inidicate a fixpoint. If an optimistic one is indicated, the known |
2112 | /// state will catch up with the assumed one, for a pessimistic fixpoint it is |
2113 | /// the other way around. |
2114 | template <typename base_ty, base_ty BestState, base_ty WorstState> |
2115 | struct IntegerStateBase : public AbstractState { |
2116 | using base_t = base_ty; |
2117 | |
2118 | IntegerStateBase() {} |
2119 | IntegerStateBase(base_t Assumed) : Assumed(Assumed) {} |
2120 | |
2121 | /// Return the best possible representable state. |
2122 | static constexpr base_t getBestState() { return BestState; } |
2123 | static constexpr base_t getBestState(const IntegerStateBase &) { |
2124 | return getBestState(); |
2125 | } |
2126 | |
2127 | /// Return the worst possible representable state. |
2128 | static constexpr base_t getWorstState() { return WorstState; } |
2129 | static constexpr base_t getWorstState(const IntegerStateBase &) { |
2130 | return getWorstState(); |
2131 | } |
2132 | |
2133 | /// See AbstractState::isValidState() |
2134 | /// NOTE: For now we simply pretend that the worst possible state is invalid. |
2135 | bool isValidState() const override { return Assumed != getWorstState(); } |
2136 | |
2137 | /// See AbstractState::isAtFixpoint() |
2138 | bool isAtFixpoint() const override { return Assumed == Known; } |
2139 | |
2140 | /// See AbstractState::indicateOptimisticFixpoint(...) |
2141 | ChangeStatus indicateOptimisticFixpoint() override { |
2142 | Known = Assumed; |
2143 | return ChangeStatus::UNCHANGED; |
2144 | } |
2145 | |
2146 | /// See AbstractState::indicatePessimisticFixpoint(...) |
2147 | ChangeStatus indicatePessimisticFixpoint() override { |
2148 | Assumed = Known; |
2149 | return ChangeStatus::CHANGED; |
2150 | } |
2151 | |
2152 | /// Return the known state encoding |
2153 | base_t getKnown() const { return Known; } |
2154 | |
2155 | /// Return the assumed state encoding. |
2156 | base_t getAssumed() const { return Assumed; } |
2157 | |
2158 | /// Equality for IntegerStateBase. |
2159 | bool |
2160 | operator==(const IntegerStateBase<base_t, BestState, WorstState> &R) const { |
2161 | return this->getAssumed() == R.getAssumed() && |
2162 | this->getKnown() == R.getKnown(); |
2163 | } |
2164 | |
2165 | /// Inequality for IntegerStateBase. |
2166 | bool |
2167 | operator!=(const IntegerStateBase<base_t, BestState, WorstState> &R) const { |
2168 | return !(*this == R); |
2169 | } |
2170 | |
2171 | /// "Clamp" this state with \p R. The result is subtype dependent but it is |
2172 | /// intended that only information assumed in both states will be assumed in |
2173 | /// this one afterwards. |
2174 | void operator^=(const IntegerStateBase<base_t, BestState, WorstState> &R) { |
2175 | handleNewAssumedValue(R.getAssumed()); |
2176 | } |
2177 | |
2178 | /// "Clamp" this state with \p R. The result is subtype dependent but it is |
2179 | /// intended that information known in either state will be known in |
2180 | /// this one afterwards. |
2181 | void operator+=(const IntegerStateBase<base_t, BestState, WorstState> &R) { |
2182 | handleNewKnownValue(R.getKnown()); |
2183 | } |
2184 | |
2185 | void operator|=(const IntegerStateBase<base_t, BestState, WorstState> &R) { |
2186 | joinOR(R.getAssumed(), R.getKnown()); |
2187 | } |
2188 | |
2189 | void operator&=(const IntegerStateBase<base_t, BestState, WorstState> &R) { |
2190 | joinAND(R.getAssumed(), R.getKnown()); |
2191 | } |
2192 | |
2193 | protected: |
2194 | /// Handle a new assumed value \p Value. Subtype dependent. |
2195 | virtual void handleNewAssumedValue(base_t Value) = 0; |
2196 | |
2197 | /// Handle a new known value \p Value. Subtype dependent. |
2198 | virtual void handleNewKnownValue(base_t Value) = 0; |
2199 | |
2200 | /// Handle a value \p Value. Subtype dependent. |
2201 | virtual void joinOR(base_t AssumedValue, base_t KnownValue) = 0; |
2202 | |
2203 | /// Handle a new assumed value \p Value. Subtype dependent. |
2204 | virtual void joinAND(base_t AssumedValue, base_t KnownValue) = 0; |
2205 | |
2206 | /// The known state encoding in an integer of type base_t. |
2207 | base_t Known = getWorstState(); |
2208 | |
2209 | /// The assumed state encoding in an integer of type base_t. |
2210 | base_t Assumed = getBestState(); |
2211 | }; |
2212 | |
2213 | /// Specialization of the integer state for a bit-wise encoding. |
2214 | template <typename base_ty = uint32_t, base_ty BestState = ~base_ty(0), |
2215 | base_ty WorstState = 0> |
2216 | struct BitIntegerState |
2217 | : public IntegerStateBase<base_ty, BestState, WorstState> { |
2218 | using base_t = base_ty; |
2219 | |
2220 | /// Return true if the bits set in \p BitsEncoding are "known bits". |
2221 | bool isKnown(base_t BitsEncoding) const { |
2222 | return (this->Known & BitsEncoding) == BitsEncoding; |
2223 | } |
2224 | |
2225 | /// Return true if the bits set in \p BitsEncoding are "assumed bits". |
2226 | bool isAssumed(base_t BitsEncoding) const { |
2227 | return (this->Assumed & BitsEncoding) == BitsEncoding; |
2228 | } |
2229 | |
2230 | /// Add the bits in \p BitsEncoding to the "known bits". |
2231 | BitIntegerState &addKnownBits(base_t Bits) { |
2232 | // Make sure we never miss any "known bits". |
2233 | this->Assumed |= Bits; |
2234 | this->Known |= Bits; |
2235 | return *this; |
2236 | } |
2237 | |
2238 | /// Remove the bits in \p BitsEncoding from the "assumed bits" if not known. |
2239 | BitIntegerState &removeAssumedBits(base_t BitsEncoding) { |
2240 | return intersectAssumedBits(~BitsEncoding); |
2241 | } |
2242 | |
2243 | /// Remove the bits in \p BitsEncoding from the "known bits". |
2244 | BitIntegerState &removeKnownBits(base_t BitsEncoding) { |
2245 | this->Known = (this->Known & ~BitsEncoding); |
2246 | return *this; |
2247 | } |
2248 | |
2249 | /// Keep only "assumed bits" also set in \p BitsEncoding but all known ones. |
2250 | BitIntegerState &intersectAssumedBits(base_t BitsEncoding) { |
2251 | // Make sure we never loose any "known bits". |
2252 | this->Assumed = (this->Assumed & BitsEncoding) | this->Known; |
2253 | return *this; |
2254 | } |
2255 | |
2256 | private: |
2257 | void handleNewAssumedValue(base_t Value) override { |
2258 | intersectAssumedBits(Value); |
2259 | } |
2260 | void handleNewKnownValue(base_t Value) override { addKnownBits(Value); } |
2261 | void joinOR(base_t AssumedValue, base_t KnownValue) override { |
2262 | this->Known |= KnownValue; |
2263 | this->Assumed |= AssumedValue; |
2264 | } |
2265 | void joinAND(base_t AssumedValue, base_t KnownValue) override { |
2266 | this->Known &= KnownValue; |
2267 | this->Assumed &= AssumedValue; |
2268 | } |
2269 | }; |
2270 | |
2271 | /// Specialization of the integer state for an increasing value, hence ~0u is |
2272 | /// the best state and 0 the worst. |
2273 | template <typename base_ty = uint32_t, base_ty BestState = ~base_ty(0), |
2274 | base_ty WorstState = 0> |
2275 | struct IncIntegerState |
2276 | : public IntegerStateBase<base_ty, BestState, WorstState> { |
2277 | using super = IntegerStateBase<base_ty, BestState, WorstState>; |
2278 | using base_t = base_ty; |
2279 | |
2280 | IncIntegerState() : super() {} |
2281 | IncIntegerState(base_t Assumed) : super(Assumed) {} |
2282 | |
2283 | /// Return the best possible representable state. |
2284 | static constexpr base_t getBestState() { return BestState; } |
2285 | static constexpr base_t |
2286 | getBestState(const IncIntegerState<base_ty, BestState, WorstState> &) { |
2287 | return getBestState(); |
2288 | } |
2289 | |
2290 | /// Take minimum of assumed and \p Value. |
2291 | IncIntegerState &takeAssumedMinimum(base_t Value) { |
2292 | // Make sure we never loose "known value". |
2293 | this->Assumed = std::max(std::min(this->Assumed, Value), this->Known); |
2294 | return *this; |
2295 | } |
2296 | |
2297 | /// Take maximum of known and \p Value. |
2298 | IncIntegerState &takeKnownMaximum(base_t Value) { |
2299 | // Make sure we never loose "known value". |
2300 | this->Assumed = std::max(Value, this->Assumed); |
2301 | this->Known = std::max(Value, this->Known); |
2302 | return *this; |
2303 | } |
2304 | |
2305 | private: |
2306 | void handleNewAssumedValue(base_t Value) override { |
2307 | takeAssumedMinimum(Value); |
2308 | } |
2309 | void handleNewKnownValue(base_t Value) override { takeKnownMaximum(Value); } |
2310 | void joinOR(base_t AssumedValue, base_t KnownValue) override { |
2311 | this->Known = std::max(this->Known, KnownValue); |
2312 | this->Assumed = std::max(this->Assumed, AssumedValue); |
2313 | } |
2314 | void joinAND(base_t AssumedValue, base_t KnownValue) override { |
2315 | this->Known = std::min(this->Known, KnownValue); |
2316 | this->Assumed = std::min(this->Assumed, AssumedValue); |
2317 | } |
2318 | }; |
2319 | |
2320 | /// Specialization of the integer state for a decreasing value, hence 0 is the |
2321 | /// best state and ~0u the worst. |
2322 | template <typename base_ty = uint32_t> |
2323 | struct DecIntegerState : public IntegerStateBase<base_ty, 0, ~base_ty(0)> { |
2324 | using base_t = base_ty; |
2325 | |
2326 | /// Take maximum of assumed and \p Value. |
2327 | DecIntegerState &takeAssumedMaximum(base_t Value) { |
2328 | // Make sure we never loose "known value". |
2329 | this->Assumed = std::min(std::max(this->Assumed, Value), this->Known); |
2330 | return *this; |
2331 | } |
2332 | |
2333 | /// Take minimum of known and \p Value. |
2334 | DecIntegerState &takeKnownMinimum(base_t Value) { |
2335 | // Make sure we never loose "known value". |
2336 | this->Assumed = std::min(Value, this->Assumed); |
2337 | this->Known = std::min(Value, this->Known); |
2338 | return *this; |
2339 | } |
2340 | |
2341 | private: |
2342 | void handleNewAssumedValue(base_t Value) override { |
2343 | takeAssumedMaximum(Value); |
2344 | } |
2345 | void handleNewKnownValue(base_t Value) override { takeKnownMinimum(Value); } |
2346 | void joinOR(base_t AssumedValue, base_t KnownValue) override { |
2347 | this->Assumed = std::min(this->Assumed, KnownValue); |
2348 | this->Assumed = std::min(this->Assumed, AssumedValue); |
2349 | } |
2350 | void joinAND(base_t AssumedValue, base_t KnownValue) override { |
2351 | this->Assumed = std::max(this->Assumed, KnownValue); |
2352 | this->Assumed = std::max(this->Assumed, AssumedValue); |
2353 | } |
2354 | }; |
2355 | |
2356 | /// Simple wrapper for a single bit (boolean) state. |
2357 | struct BooleanState : public IntegerStateBase<bool, 1, 0> { |
2358 | using super = IntegerStateBase<bool, 1, 0>; |
2359 | using base_t = IntegerStateBase::base_t; |
2360 | |
2361 | BooleanState() : super() {} |
2362 | BooleanState(base_t Assumed) : super(Assumed) {} |
2363 | |
2364 | /// Set the assumed value to \p Value but never below the known one. |
2365 | void setAssumed(bool Value) { Assumed &= (Known | Value); } |
2366 | |
2367 | /// Set the known and asssumed value to \p Value. |
2368 | void setKnown(bool Value) { |
2369 | Known |= Value; |
2370 | Assumed |= Value; |
2371 | } |
2372 | |
2373 | /// Return true if the state is assumed to hold. |
2374 | bool isAssumed() const { return getAssumed(); } |
2375 | |
2376 | /// Return true if the state is known to hold. |
2377 | bool isKnown() const { return getKnown(); } |
2378 | |
2379 | private: |
2380 | void handleNewAssumedValue(base_t Value) override { |
2381 | if (!Value) |
2382 | Assumed = Known; |
2383 | } |
2384 | void handleNewKnownValue(base_t Value) override { |
2385 | if (Value) |
2386 | Known = (Assumed = Value); |
2387 | } |
2388 | void joinOR(base_t AssumedValue, base_t KnownValue) override { |
2389 | Known |= KnownValue; |
2390 | Assumed |= AssumedValue; |
2391 | } |
2392 | void joinAND(base_t AssumedValue, base_t KnownValue) override { |
2393 | Known &= KnownValue; |
2394 | Assumed &= AssumedValue; |
2395 | } |
2396 | }; |
2397 | |
2398 | /// State for an integer range. |
2399 | struct IntegerRangeState : public AbstractState { |
2400 | |
2401 | /// Bitwidth of the associated value. |
2402 | uint32_t BitWidth; |
2403 | |
2404 | /// State representing assumed range, initially set to empty. |
2405 | ConstantRange Assumed; |
2406 | |
2407 | /// State representing known range, initially set to [-inf, inf]. |
2408 | ConstantRange Known; |
2409 | |
2410 | IntegerRangeState(uint32_t BitWidth) |
2411 | : BitWidth(BitWidth), Assumed(ConstantRange::getEmpty(BitWidth)), |
2412 | Known(ConstantRange::getFull(BitWidth)) {} |
2413 | |
2414 | IntegerRangeState(const ConstantRange &CR) |
2415 | : BitWidth(CR.getBitWidth()), Assumed(CR), |
2416 | Known(getWorstState(CR.getBitWidth())) {} |
2417 | |
2418 | /// Return the worst possible representable state. |
2419 | static ConstantRange getWorstState(uint32_t BitWidth) { |
2420 | return ConstantRange::getFull(BitWidth); |
2421 | } |
2422 | |
2423 | /// Return the best possible representable state. |
2424 | static ConstantRange getBestState(uint32_t BitWidth) { |
2425 | return ConstantRange::getEmpty(BitWidth); |
2426 | } |
2427 | static ConstantRange getBestState(const IntegerRangeState &IRS) { |
2428 | return getBestState(IRS.getBitWidth()); |
2429 | } |
2430 | |
2431 | /// Return associated values' bit width. |
2432 | uint32_t getBitWidth() const { return BitWidth; } |
2433 | |
2434 | /// See AbstractState::isValidState() |
2435 | bool isValidState() const override { |
2436 | return BitWidth > 0 && !Assumed.isFullSet(); |
2437 | } |
2438 | |
2439 | /// See AbstractState::isAtFixpoint() |
2440 | bool isAtFixpoint() const override { return Assumed == Known; } |
2441 | |
2442 | /// See AbstractState::indicateOptimisticFixpoint(...) |
2443 | ChangeStatus indicateOptimisticFixpoint() override { |
2444 | Known = Assumed; |
2445 | return ChangeStatus::CHANGED; |
2446 | } |
2447 | |
2448 | /// See AbstractState::indicatePessimisticFixpoint(...) |
2449 | ChangeStatus indicatePessimisticFixpoint() override { |
2450 | Assumed = Known; |
2451 | return ChangeStatus::CHANGED; |
2452 | } |
2453 | |
2454 | /// Return the known state encoding |
2455 | ConstantRange getKnown() const { return Known; } |
2456 | |
2457 | /// Return the assumed state encoding. |
2458 | ConstantRange getAssumed() const { return Assumed; } |
2459 | |
2460 | /// Unite assumed range with the passed state. |
2461 | void unionAssumed(const ConstantRange &R) { |
2462 | // Don't loose a known range. |
2463 | Assumed = Assumed.unionWith(R).intersectWith(Known); |
2464 | } |
2465 | |
2466 | /// See IntegerRangeState::unionAssumed(..). |
2467 | void unionAssumed(const IntegerRangeState &R) { |
2468 | unionAssumed(R.getAssumed()); |
2469 | } |
2470 | |
2471 | /// Unite known range with the passed state. |
2472 | void unionKnown(const ConstantRange &R) { |
2473 | // Don't loose a known range. |
2474 | Known = Known.unionWith(R); |
2475 | Assumed = Assumed.unionWith(Known); |
2476 | } |
2477 | |
2478 | /// See IntegerRangeState::unionKnown(..). |
2479 | void unionKnown(const IntegerRangeState &R) { unionKnown(R.getKnown()); } |
2480 | |
2481 | /// Intersect known range with the passed state. |
2482 | void intersectKnown(const ConstantRange &R) { |
2483 | Assumed = Assumed.intersectWith(R); |
2484 | Known = Known.intersectWith(R); |
2485 | } |
2486 | |
2487 | /// See IntegerRangeState::intersectKnown(..). |
2488 | void intersectKnown(const IntegerRangeState &R) { |
2489 | intersectKnown(R.getKnown()); |
2490 | } |
2491 | |
2492 | /// Equality for IntegerRangeState. |
2493 | bool operator==(const IntegerRangeState &R) const { |
2494 | return getAssumed() == R.getAssumed() && getKnown() == R.getKnown(); |
2495 | } |
2496 | |
2497 | /// "Clamp" this state with \p R. The result is subtype dependent but it is |
2498 | /// intended that only information assumed in both states will be assumed in |
2499 | /// this one afterwards. |
2500 | IntegerRangeState operator^=(const IntegerRangeState &R) { |
2501 | // NOTE: `^=` operator seems like `intersect` but in this case, we need to |
2502 | // take `union`. |
2503 | unionAssumed(R); |
2504 | return *this; |
2505 | } |
2506 | |
2507 | IntegerRangeState operator&=(const IntegerRangeState &R) { |
2508 | // NOTE: `&=` operator seems like `intersect` but in this case, we need to |
2509 | // take `union`. |
2510 | unionKnown(R); |
2511 | unionAssumed(R); |
2512 | return *this; |
2513 | } |
2514 | }; |
2515 | /// Helper struct necessary as the modular build fails if the virtual method |
2516 | /// IRAttribute::manifest is defined in the Attributor.cpp. |
2517 | struct IRAttributeManifest { |
2518 | static ChangeStatus manifestAttrs(Attributor &A, const IRPosition &IRP, |
2519 | const ArrayRef<Attribute> &DeducedAttrs, |
2520 | bool ForceReplace = false); |
2521 | }; |
2522 | |
2523 | /// Helper to tie a abstract state implementation to an abstract attribute. |
2524 | template <typename StateTy, typename BaseType, class... Ts> |
2525 | struct StateWrapper : public BaseType, public StateTy { |
2526 | /// Provide static access to the type of the state. |
2527 | using StateType = StateTy; |
2528 | |
2529 | StateWrapper(const IRPosition &IRP, Ts... Args) |
2530 | : BaseType(IRP), StateTy(Args...) {} |
2531 | |
2532 | /// See AbstractAttribute::getState(...). |
2533 | StateType &getState() override { return *this; } |
2534 | |
2535 | /// See AbstractAttribute::getState(...). |
2536 | const StateType &getState() const override { return *this; } |
2537 | }; |
2538 | |
2539 | /// Helper class that provides common functionality to manifest IR attributes. |
2540 | template <Attribute::AttrKind AK, typename BaseType> |
2541 | struct IRAttribute : public BaseType { |
2542 | IRAttribute(const IRPosition &IRP) : BaseType(IRP) {} |
2543 | |
2544 | /// See AbstractAttribute::initialize(...). |
2545 | virtual void initialize(Attributor &A) override { |
2546 | const IRPosition &IRP = this->getIRPosition(); |
2547 | if (isa<UndefValue>(IRP.getAssociatedValue()) || |
2548 | this->hasAttr(getAttrKind(), /* IgnoreSubsumingPositions */ false, |
2549 | &A)) { |
2550 | this->getState().indicateOptimisticFixpoint(); |
2551 | return; |
2552 | } |
2553 | |
2554 | bool IsFnInterface = IRP.isFnInterfaceKind(); |
2555 | const Function *FnScope = IRP.getAnchorScope(); |
2556 | // TODO: Not all attributes require an exact definition. Find a way to |
2557 | // enable deduction for some but not all attributes in case the |
2558 | // definition might be changed at runtime, see also |
2559 | // http://lists.llvm.org/pipermail/llvm-dev/2018-February/121275.html. |
2560 | // TODO: We could always determine abstract attributes and if sufficient |
2561 | // information was found we could duplicate the functions that do not |
2562 | // have an exact definition. |
2563 | if (IsFnInterface && (!FnScope || !A.isFunctionIPOAmendable(*FnScope))) |
2564 | this->getState().indicatePessimisticFixpoint(); |
2565 | } |
2566 | |
2567 | /// See AbstractAttribute::manifest(...). |
2568 | ChangeStatus manifest(Attributor &A) override { |
2569 | if (isa<UndefValue>(this->getIRPosition().getAssociatedValue())) |
2570 | return ChangeStatus::UNCHANGED; |
2571 | SmallVector<Attribute, 4> DeducedAttrs; |
2572 | getDeducedAttributes(this->getAnchorValue().getContext(), DeducedAttrs); |
2573 | return IRAttributeManifest::manifestAttrs(A, this->getIRPosition(), |
2574 | DeducedAttrs); |
2575 | } |
2576 | |
2577 | /// Return the kind that identifies the abstract attribute implementation. |
2578 | Attribute::AttrKind getAttrKind() const { return AK; } |
2579 | |
2580 | /// Return the deduced attributes in \p Attrs. |
2581 | virtual void getDeducedAttributes(LLVMContext &Ctx, |
2582 | SmallVectorImpl<Attribute> &Attrs) const { |
2583 | Attrs.emplace_back(Attribute::get(Ctx, getAttrKind())); |
2584 | } |
2585 | }; |
2586 | |
2587 | /// Base struct for all "concrete attribute" deductions. |
2588 | /// |
2589 | /// The abstract attribute is a minimal interface that allows the Attributor to |
2590 | /// orchestrate the abstract/fixpoint analysis. The design allows to hide away |
2591 | /// implementation choices made for the subclasses but also to structure their |
2592 | /// implementation and simplify the use of other abstract attributes in-flight. |
2593 | /// |
2594 | /// To allow easy creation of new attributes, most methods have default |
2595 | /// implementations. The ones that do not are generally straight forward, except |
2596 | /// `AbstractAttribute::updateImpl` which is the location of most reasoning |
2597 | /// associated with the abstract attribute. The update is invoked by the |
2598 | /// Attributor in case the situation used to justify the current optimistic |
2599 | /// state might have changed. The Attributor determines this automatically |
2600 | /// by monitoring the `Attributor::getAAFor` calls made by abstract attributes. |
2601 | /// |
2602 | /// The `updateImpl` method should inspect the IR and other abstract attributes |
2603 | /// in-flight to justify the best possible (=optimistic) state. The actual |
2604 | /// implementation is, similar to the underlying abstract state encoding, not |
2605 | /// exposed. In the most common case, the `updateImpl` will go through a list of |
2606 | /// reasons why its optimistic state is valid given the current information. If |
2607 | /// any combination of them holds and is sufficient to justify the current |
2608 | /// optimistic state, the method shall return UNCHAGED. If not, the optimistic |
2609 | /// state is adjusted to the situation and the method shall return CHANGED. |
2610 | /// |
2611 | /// If the manifestation of the "concrete attribute" deduced by the subclass |
2612 | /// differs from the "default" behavior, which is a (set of) LLVM-IR |
2613 | /// attribute(s) for an argument, call site argument, function return value, or |
2614 | /// function, the `AbstractAttribute::manifest` method should be overloaded. |
2615 | /// |
2616 | /// NOTE: If the state obtained via getState() is INVALID, thus if |
2617 | /// AbstractAttribute::getState().isValidState() returns false, no |
2618 | /// information provided by the methods of this class should be used. |
2619 | /// NOTE: The Attributor currently has certain limitations to what we can do. |
2620 | /// As a general rule of thumb, "concrete" abstract attributes should *for |
2621 | /// now* only perform "backward" information propagation. That means |
2622 | /// optimistic information obtained through abstract attributes should |
2623 | /// only be used at positions that precede the origin of the information |
2624 | /// with regards to the program flow. More practically, information can |
2625 | /// *now* be propagated from instructions to their enclosing function, but |
2626 | /// *not* from call sites to the called function. The mechanisms to allow |
2627 | /// both directions will be added in the future. |
2628 | /// NOTE: The mechanics of adding a new "concrete" abstract attribute are |
2629 | /// described in the file comment. |
2630 | struct AbstractAttribute : public IRPosition, public AADepGraphNode { |
2631 | using StateType = AbstractState; |
2632 | |
2633 | AbstractAttribute(const IRPosition &IRP) : IRPosition(IRP) {} |
2634 | |
2635 | /// Virtual destructor. |
2636 | virtual ~AbstractAttribute() {} |
2637 | |
2638 | /// This function is used to identify if an \p DGN is of type |
2639 | /// AbstractAttribute so that the dyn_cast and cast can use such information |
2640 | /// to cast an AADepGraphNode to an AbstractAttribute. |
2641 | /// |
2642 | /// We eagerly return true here because all AADepGraphNodes except for the |
2643 | /// Synthethis Node are of type AbstractAttribute |
2644 | static bool classof(const AADepGraphNode *DGN) { return true; } |
2645 | |
2646 | /// Initialize the state with the information in the Attributor \p A. |
2647 | /// |
2648 | /// This function is called by the Attributor once all abstract attributes |
2649 | /// have been identified. It can and shall be used for task like: |
2650 | /// - identify existing knowledge in the IR and use it for the "known state" |
2651 | /// - perform any work that is not going to change over time, e.g., determine |
2652 | /// a subset of the IR, or attributes in-flight, that have to be looked at |
2653 | /// in the `updateImpl` method. |
2654 | virtual void initialize(Attributor &A) {} |
2655 | |
2656 | /// Return the internal abstract state for inspection. |
2657 | virtual StateType &getState() = 0; |
2658 | virtual const StateType &getState() const = 0; |
2659 | |
2660 | /// Return an IR position, see struct IRPosition. |
2661 | const IRPosition &getIRPosition() const { return *this; }; |
2662 | IRPosition &getIRPosition() { return *this; }; |
2663 | |
2664 | /// Helper functions, for debug purposes only. |
2665 | ///{ |
2666 | void print(raw_ostream &OS) const override; |
2667 | virtual void printWithDeps(raw_ostream &OS) const; |
2668 | void dump() const { print(dbgs()); } |
2669 | |
2670 | /// This function should return the "summarized" assumed state as string. |
2671 | virtual const std::string getAsStr() const = 0; |
2672 | |
2673 | /// This function should return the name of the AbstractAttribute |
2674 | virtual const std::string getName() const = 0; |
2675 | |
2676 | /// This function should return the address of the ID of the AbstractAttribute |
2677 | virtual const char *getIdAddr() const = 0; |
2678 | ///} |
2679 | |
2680 | /// Allow the Attributor access to the protected methods. |
2681 | friend struct Attributor; |
2682 | |
2683 | protected: |
2684 | /// Hook for the Attributor to trigger an update of the internal state. |
2685 | /// |
2686 | /// If this attribute is already fixed, this method will return UNCHANGED, |
2687 | /// otherwise it delegates to `AbstractAttribute::updateImpl`. |
2688 | /// |
2689 | /// \Return CHANGED if the internal state changed, otherwise UNCHANGED. |
2690 | ChangeStatus update(Attributor &A); |
2691 | |
2692 | /// Hook for the Attributor to trigger the manifestation of the information |
2693 | /// represented by the abstract attribute in the LLVM-IR. |
2694 | /// |
2695 | /// \Return CHANGED if the IR was altered, otherwise UNCHANGED. |
2696 | virtual ChangeStatus manifest(Attributor &A) { |
2697 | return ChangeStatus::UNCHANGED; |
2698 | } |
2699 | |
2700 | /// Hook to enable custom statistic tracking, called after manifest that |
2701 | /// resulted in a change if statistics are enabled. |
2702 | /// |
2703 | /// We require subclasses to provide an implementation so we remember to |
2704 | /// add statistics for them. |
2705 | virtual void trackStatistics() const = 0; |
2706 | |
2707 | /// The actual update/transfer function which has to be implemented by the |
2708 | /// derived classes. |
2709 | /// |
2710 | /// If it is called, the environment has changed and we have to determine if |
2711 | /// the current information is still valid or adjust it otherwise. |
2712 | /// |
2713 | /// \Return CHANGED if the internal state changed, otherwise UNCHANGED. |
2714 | virtual ChangeStatus updateImpl(Attributor &A) = 0; |
2715 | }; |
2716 | |
2717 | /// Forward declarations of output streams for debug purposes. |
2718 | /// |
2719 | ///{ |
2720 | raw_ostream &operator<<(raw_ostream &OS, const AbstractAttribute &AA); |
2721 | raw_ostream &operator<<(raw_ostream &OS, ChangeStatus S); |
2722 | raw_ostream &operator<<(raw_ostream &OS, IRPosition::Kind); |
2723 | raw_ostream &operator<<(raw_ostream &OS, const IRPosition &); |
2724 | raw_ostream &operator<<(raw_ostream &OS, const AbstractState &State); |
2725 | template <typename base_ty, base_ty BestState, base_ty WorstState> |
2726 | raw_ostream & |
2727 | operator<<(raw_ostream &OS, |
2728 | const IntegerStateBase<base_ty, BestState, WorstState> &S) { |
2729 | return OS << "(" << S.getKnown() << "-" << S.getAssumed() << ")" |
2730 | << static_cast<const AbstractState &>(S); |
2731 | } |
2732 | raw_ostream &operator<<(raw_ostream &OS, const IntegerRangeState &State); |
2733 | ///} |
2734 | |
2735 | struct AttributorPass : public PassInfoMixin<AttributorPass> { |
2736 | PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM); |
2737 | }; |
2738 | struct AttributorCGSCCPass : public PassInfoMixin<AttributorCGSCCPass> { |
2739 | PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM, |
2740 | LazyCallGraph &CG, CGSCCUpdateResult &UR); |
2741 | }; |
2742 | |
2743 | Pass *createAttributorLegacyPass(); |
2744 | Pass *createAttributorCGSCCLegacyPass(); |
2745 | |
2746 | /// Helper function to clamp a state \p S of type \p StateType with the |
2747 | /// information in \p R and indicate/return if \p S did change (as-in update is |
2748 | /// required to be run again). |
2749 | template <typename StateType> |
2750 | ChangeStatus clampStateAndIndicateChange(StateType &S, const StateType &R) { |
2751 | auto Assumed = S.getAssumed(); |
2752 | S ^= R; |
2753 | return Assumed == S.getAssumed() ? ChangeStatus::UNCHANGED |
2754 | : ChangeStatus::CHANGED; |
2755 | } |
2756 | |
2757 | /// ---------------------------------------------------------------------------- |
2758 | /// Abstract Attribute Classes |
2759 | /// ---------------------------------------------------------------------------- |
2760 | |
2761 | /// An abstract attribute for the returned values of a function. |
2762 | struct AAReturnedValues |
2763 | : public IRAttribute<Attribute::Returned, AbstractAttribute> { |
2764 | AAReturnedValues(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
2765 | |
2766 | /// Return an assumed unique return value if a single candidate is found. If |
2767 | /// there cannot be one, return a nullptr. If it is not clear yet, return the |
2768 | /// Optional::NoneType. |
2769 | Optional<Value *> getAssumedUniqueReturnValue(Attributor &A) const; |
2770 | |
2771 | /// Check \p Pred on all returned values. |
2772 | /// |
2773 | /// This method will evaluate \p Pred on returned values and return |
2774 | /// true if (1) all returned values are known, and (2) \p Pred returned true |
2775 | /// for all returned values. |
2776 | /// |
2777 | /// Note: Unlike the Attributor::checkForAllReturnedValuesAndReturnInsts |
2778 | /// method, this one will not filter dead return instructions. |
2779 | virtual bool checkForAllReturnedValuesAndReturnInsts( |
2780 | function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred) |
2781 | const = 0; |
2782 | |
2783 | using iterator = |
2784 | MapVector<Value *, SmallSetVector<ReturnInst *, 4>>::iterator; |
2785 | using const_iterator = |
2786 | MapVector<Value *, SmallSetVector<ReturnInst *, 4>>::const_iterator; |
2787 | virtual llvm::iterator_range<iterator> returned_values() = 0; |
2788 | virtual llvm::iterator_range<const_iterator> returned_values() const = 0; |
2789 | |
2790 | virtual size_t getNumReturnValues() const = 0; |
2791 | |
2792 | /// Create an abstract attribute view for the position \p IRP. |
2793 | static AAReturnedValues &createForPosition(const IRPosition &IRP, |
2794 | Attributor &A); |
2795 | |
2796 | /// See AbstractAttribute::getName() |
2797 | const std::string getName() const override { return "AAReturnedValues"; } |
2798 | |
2799 | /// See AbstractAttribute::getIdAddr() |
2800 | const char *getIdAddr() const override { return &ID; } |
2801 | |
2802 | /// This function should return true if the type of the \p AA is |
2803 | /// AAReturnedValues |
2804 | static bool classof(const AbstractAttribute *AA) { |
2805 | return (AA->getIdAddr() == &ID); |
2806 | } |
2807 | |
2808 | /// Unique ID (due to the unique address) |
2809 | static const char ID; |
2810 | }; |
2811 | |
2812 | struct AANoUnwind |
2813 | : public IRAttribute<Attribute::NoUnwind, |
2814 | StateWrapper<BooleanState, AbstractAttribute>> { |
2815 | AANoUnwind(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
2816 | |
2817 | /// Returns true if nounwind is assumed. |
2818 | bool isAssumedNoUnwind() const { return getAssumed(); } |
2819 | |
2820 | /// Returns true if nounwind is known. |
2821 | bool isKnownNoUnwind() const { return getKnown(); } |
2822 | |
2823 | /// Create an abstract attribute view for the position \p IRP. |
2824 | static AANoUnwind &createForPosition(const IRPosition &IRP, Attributor &A); |
2825 | |
2826 | /// See AbstractAttribute::getName() |
2827 | const std::string getName() const override { return "AANoUnwind"; } |
2828 | |
2829 | /// See AbstractAttribute::getIdAddr() |
2830 | const char *getIdAddr() const override { return &ID; } |
2831 | |
2832 | /// This function should return true if the type of the \p AA is AANoUnwind |
2833 | static bool classof(const AbstractAttribute *AA) { |
2834 | return (AA->getIdAddr() == &ID); |
2835 | } |
2836 | |
2837 | /// Unique ID (due to the unique address) |
2838 | static const char ID; |
2839 | }; |
2840 | |
2841 | struct AANoSync |
2842 | : public IRAttribute<Attribute::NoSync, |
2843 | StateWrapper<BooleanState, AbstractAttribute>> { |
2844 | AANoSync(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
2845 | |
2846 | /// Returns true if "nosync" is assumed. |
2847 | bool isAssumedNoSync() const { return getAssumed(); } |
2848 | |
2849 | /// Returns true if "nosync" is known. |
2850 | bool isKnownNoSync() const { return getKnown(); } |
2851 | |
2852 | /// Create an abstract attribute view for the position \p IRP. |
2853 | static AANoSync &createForPosition(const IRPosition &IRP, Attributor &A); |
2854 | |
2855 | /// See AbstractAttribute::getName() |
2856 | const std::string getName() const override { return "AANoSync"; } |
2857 | |
2858 | /// See AbstractAttribute::getIdAddr() |
2859 | const char *getIdAddr() const override { return &ID; } |
2860 | |
2861 | /// This function should return true if the type of the \p AA is AANoSync |
2862 | static bool classof(const AbstractAttribute *AA) { |
2863 | return (AA->getIdAddr() == &ID); |
2864 | } |
2865 | |
2866 | /// Unique ID (due to the unique address) |
2867 | static const char ID; |
2868 | }; |
2869 | |
2870 | /// An abstract interface for all nonnull attributes. |
2871 | struct AANonNull |
2872 | : public IRAttribute<Attribute::NonNull, |
2873 | StateWrapper<BooleanState, AbstractAttribute>> { |
2874 | AANonNull(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
2875 | |
2876 | /// Return true if we assume that the underlying value is nonnull. |
2877 | bool isAssumedNonNull() const { return getAssumed(); } |
2878 | |
2879 | /// Return true if we know that underlying value is nonnull. |
2880 | bool isKnownNonNull() const { return getKnown(); } |
2881 | |
2882 | /// Create an abstract attribute view for the position \p IRP. |
2883 | static AANonNull &createForPosition(const IRPosition &IRP, Attributor &A); |
2884 | |
2885 | /// See AbstractAttribute::getName() |
2886 | const std::string getName() const override { return "AANonNull"; } |
2887 | |
2888 | /// See AbstractAttribute::getIdAddr() |
2889 | const char *getIdAddr() const override { return &ID; } |
2890 | |
2891 | /// This function should return true if the type of the \p AA is AANonNull |
2892 | static bool classof(const AbstractAttribute *AA) { |
2893 | return (AA->getIdAddr() == &ID); |
2894 | } |
2895 | |
2896 | /// Unique ID (due to the unique address) |
2897 | static const char ID; |
2898 | }; |
2899 | |
2900 | /// An abstract attribute for norecurse. |
2901 | struct AANoRecurse |
2902 | : public IRAttribute<Attribute::NoRecurse, |
2903 | StateWrapper<BooleanState, AbstractAttribute>> { |
2904 | AANoRecurse(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
2905 | |
2906 | /// Return true if "norecurse" is assumed. |
2907 | bool isAssumedNoRecurse() const { return getAssumed(); } |
2908 | |
2909 | /// Return true if "norecurse" is known. |
2910 | bool isKnownNoRecurse() const { return getKnown(); } |
2911 | |
2912 | /// Create an abstract attribute view for the position \p IRP. |
2913 | static AANoRecurse &createForPosition(const IRPosition &IRP, Attributor &A); |
2914 | |
2915 | /// See AbstractAttribute::getName() |
2916 | const std::string getName() const override { return "AANoRecurse"; } |
2917 | |
2918 | /// See AbstractAttribute::getIdAddr() |
2919 | const char *getIdAddr() const override { return &ID; } |
2920 | |
2921 | /// This function should return true if the type of the \p AA is AANoRecurse |
2922 | static bool classof(const AbstractAttribute *AA) { |
2923 | return (AA->getIdAddr() == &ID); |
2924 | } |
2925 | |
2926 | /// Unique ID (due to the unique address) |
2927 | static const char ID; |
2928 | }; |
2929 | |
2930 | /// An abstract attribute for willreturn. |
2931 | struct AAWillReturn |
2932 | : public IRAttribute<Attribute::WillReturn, |
2933 | StateWrapper<BooleanState, AbstractAttribute>> { |
2934 | AAWillReturn(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
2935 | |
2936 | /// Return true if "willreturn" is assumed. |
2937 | bool isAssumedWillReturn() const { return getAssumed(); } |
2938 | |
2939 | /// Return true if "willreturn" is known. |
2940 | bool isKnownWillReturn() const { return getKnown(); } |
2941 | |
2942 | /// Create an abstract attribute view for the position \p IRP. |
2943 | static AAWillReturn &createForPosition(const IRPosition &IRP, Attributor &A); |
2944 | |
2945 | /// See AbstractAttribute::getName() |
2946 | const std::string getName() const override { return "AAWillReturn"; } |
2947 | |
2948 | /// See AbstractAttribute::getIdAddr() |
2949 | const char *getIdAddr() const override { return &ID; } |
2950 | |
2951 | /// This function should return true if the type of the \p AA is AAWillReturn |
2952 | static bool classof(const AbstractAttribute *AA) { |
2953 | return (AA->getIdAddr() == &ID); |
2954 | } |
2955 | |
2956 | /// Unique ID (due to the unique address) |
2957 | static const char ID; |
2958 | }; |
2959 | |
2960 | /// An abstract attribute for undefined behavior. |
2961 | struct AAUndefinedBehavior |
2962 | : public StateWrapper<BooleanState, AbstractAttribute> { |
2963 | using Base = StateWrapper<BooleanState, AbstractAttribute>; |
2964 | AAUndefinedBehavior(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
2965 | |
2966 | /// Return true if "undefined behavior" is assumed. |
2967 | bool isAssumedToCauseUB() const { return getAssumed(); } |
2968 | |
2969 | /// Return true if "undefined behavior" is assumed for a specific instruction. |
2970 | virtual bool isAssumedToCauseUB(Instruction *I) const = 0; |
2971 | |
2972 | /// Return true if "undefined behavior" is known. |
2973 | bool isKnownToCauseUB() const { return getKnown(); } |
2974 | |
2975 | /// Return true if "undefined behavior" is known for a specific instruction. |
2976 | virtual bool isKnownToCauseUB(Instruction *I) const = 0; |
2977 | |
2978 | /// Create an abstract attribute view for the position \p IRP. |
2979 | static AAUndefinedBehavior &createForPosition(const IRPosition &IRP, |
2980 | Attributor &A); |
2981 | |
2982 | /// See AbstractAttribute::getName() |
2983 | const std::string getName() const override { return "AAUndefinedBehavior"; } |
2984 | |
2985 | /// See AbstractAttribute::getIdAddr() |
2986 | const char *getIdAddr() const override { return &ID; } |
2987 | |
2988 | /// This function should return true if the type of the \p AA is |
2989 | /// AAUndefineBehavior |
2990 | static bool classof(const AbstractAttribute *AA) { |
2991 | return (AA->getIdAddr() == &ID); |
2992 | } |
2993 | |
2994 | /// Unique ID (due to the unique address) |
2995 | static const char ID; |
2996 | }; |
2997 | |
2998 | /// An abstract interface to determine reachability of point A to B. |
2999 | struct AAReachability : public StateWrapper<BooleanState, AbstractAttribute> { |
3000 | using Base = StateWrapper<BooleanState, AbstractAttribute>; |
3001 | AAReachability(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
3002 | |
3003 | /// Returns true if 'From' instruction is assumed to reach, 'To' instruction. |
3004 | /// Users should provide two positions they are interested in, and the class |
3005 | /// determines (and caches) reachability. |
3006 | bool isAssumedReachable(Attributor &A, const Instruction &From, |
3007 | const Instruction &To) const { |
3008 | if (!getState().isValidState()) |
3009 | return true; |
3010 | return A.getInfoCache().getPotentiallyReachable(From, To); |
3011 | } |
3012 | |
3013 | /// Returns true if 'From' instruction is known to reach, 'To' instruction. |
3014 | /// Users should provide two positions they are interested in, and the class |
3015 | /// determines (and caches) reachability. |
3016 | bool isKnownReachable(Attributor &A, const Instruction &From, |
3017 | const Instruction &To) const { |
3018 | if (!getState().isValidState()) |
3019 | return false; |
3020 | return A.getInfoCache().getPotentiallyReachable(From, To); |
3021 | } |
3022 | |
3023 | /// Create an abstract attribute view for the position \p IRP. |
3024 | static AAReachability &createForPosition(const IRPosition &IRP, |
3025 | Attributor &A); |
3026 | |
3027 | /// See AbstractAttribute::getName() |
3028 | const std::string getName() const override { return "AAReachability"; } |
3029 | |
3030 | /// See AbstractAttribute::getIdAddr() |
3031 | const char *getIdAddr() const override { return &ID; } |
3032 | |
3033 | /// This function should return true if the type of the \p AA is |
3034 | /// AAReachability |
3035 | static bool classof(const AbstractAttribute *AA) { |
3036 | return (AA->getIdAddr() == &ID); |
3037 | } |
3038 | |
3039 | /// Unique ID (due to the unique address) |
3040 | static const char ID; |
3041 | }; |
3042 | |
3043 | /// An abstract interface for all noalias attributes. |
3044 | struct AANoAlias |
3045 | : public IRAttribute<Attribute::NoAlias, |
3046 | StateWrapper<BooleanState, AbstractAttribute>> { |
3047 | AANoAlias(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3048 | |
3049 | /// Return true if we assume that the underlying value is alias. |
3050 | bool isAssumedNoAlias() const { return getAssumed(); } |
3051 | |
3052 | /// Return true if we know that underlying value is noalias. |
3053 | bool isKnownNoAlias() const { return getKnown(); } |
3054 | |
3055 | /// Create an abstract attribute view for the position \p IRP. |
3056 | static AANoAlias &createForPosition(const IRPosition &IRP, Attributor &A); |
3057 | |
3058 | /// See AbstractAttribute::getName() |
3059 | const std::string getName() const override { return "AANoAlias"; } |
3060 | |
3061 | /// See AbstractAttribute::getIdAddr() |
3062 | const char *getIdAddr() const override { return &ID; } |
3063 | |
3064 | /// This function should return true if the type of the \p AA is AANoAlias |
3065 | static bool classof(const AbstractAttribute *AA) { |
3066 | return (AA->getIdAddr() == &ID); |
3067 | } |
3068 | |
3069 | /// Unique ID (due to the unique address) |
3070 | static const char ID; |
3071 | }; |
3072 | |
3073 | /// An AbstractAttribute for nofree. |
3074 | struct AANoFree |
3075 | : public IRAttribute<Attribute::NoFree, |
3076 | StateWrapper<BooleanState, AbstractAttribute>> { |
3077 | AANoFree(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3078 | |
3079 | /// Return true if "nofree" is assumed. |
3080 | bool isAssumedNoFree() const { return getAssumed(); } |
3081 | |
3082 | /// Return true if "nofree" is known. |
3083 | bool isKnownNoFree() const { return getKnown(); } |
3084 | |
3085 | /// Create an abstract attribute view for the position \p IRP. |
3086 | static AANoFree &createForPosition(const IRPosition &IRP, Attributor &A); |
3087 | |
3088 | /// See AbstractAttribute::getName() |
3089 | const std::string getName() const override { return "AANoFree"; } |
3090 | |
3091 | /// See AbstractAttribute::getIdAddr() |
3092 | const char *getIdAddr() const override { return &ID; } |
3093 | |
3094 | /// This function should return true if the type of the \p AA is AANoFree |
3095 | static bool classof(const AbstractAttribute *AA) { |
3096 | return (AA->getIdAddr() == &ID); |
3097 | } |
3098 | |
3099 | /// Unique ID (due to the unique address) |
3100 | static const char ID; |
3101 | }; |
3102 | |
3103 | /// An AbstractAttribute for noreturn. |
3104 | struct AANoReturn |
3105 | : public IRAttribute<Attribute::NoReturn, |
3106 | StateWrapper<BooleanState, AbstractAttribute>> { |
3107 | AANoReturn(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3108 | |
3109 | /// Return true if the underlying object is assumed to never return. |
3110 | bool isAssumedNoReturn() const { return getAssumed(); } |
3111 | |
3112 | /// Return true if the underlying object is known to never return. |
3113 | bool isKnownNoReturn() const { return getKnown(); } |
3114 | |
3115 | /// Create an abstract attribute view for the position \p IRP. |
3116 | static AANoReturn &createForPosition(const IRPosition &IRP, Attributor &A); |
3117 | |
3118 | /// See AbstractAttribute::getName() |
3119 | const std::string getName() const override { return "AANoReturn"; } |
3120 | |
3121 | /// See AbstractAttribute::getIdAddr() |
3122 | const char *getIdAddr() const override { return &ID; } |
3123 | |
3124 | /// This function should return true if the type of the \p AA is AANoReturn |
3125 | static bool classof(const AbstractAttribute *AA) { |
3126 | return (AA->getIdAddr() == &ID); |
3127 | } |
3128 | |
3129 | /// Unique ID (due to the unique address) |
3130 | static const char ID; |
3131 | }; |
3132 | |
3133 | /// An abstract interface for liveness abstract attribute. |
3134 | struct AAIsDead |
3135 | : public StateWrapper<BitIntegerState<uint8_t, 3, 0>, AbstractAttribute> { |
3136 | using Base = StateWrapper<BitIntegerState<uint8_t, 3, 0>, AbstractAttribute>; |
3137 | AAIsDead(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
3138 | |
3139 | /// State encoding bits. A set bit in the state means the property holds. |
3140 | enum { |
3141 | HAS_NO_EFFECT = 1 << 0, |
3142 | IS_REMOVABLE = 1 << 1, |
3143 | |
3144 | IS_DEAD = HAS_NO_EFFECT | IS_REMOVABLE, |
3145 | }; |
3146 | static_assert(IS_DEAD == getBestState(), "Unexpected BEST_STATE value"); |
3147 | |
3148 | protected: |
3149 | /// The query functions are protected such that other attributes need to go |
3150 | /// through the Attributor interfaces: `Attributor::isAssumedDead(...)` |
3151 | |
3152 | /// Returns true if the underlying value is assumed dead. |
3153 | virtual bool isAssumedDead() const = 0; |
3154 | |
3155 | /// Returns true if the underlying value is known dead. |
3156 | virtual bool isKnownDead() const = 0; |
3157 | |
3158 | /// Returns true if \p BB is assumed dead. |
3159 | virtual bool isAssumedDead(const BasicBlock *BB) const = 0; |
3160 | |
3161 | /// Returns true if \p BB is known dead. |
3162 | virtual bool isKnownDead(const BasicBlock *BB) const = 0; |
3163 | |
3164 | /// Returns true if \p I is assumed dead. |
3165 | virtual bool isAssumedDead(const Instruction *I) const = 0; |
3166 | |
3167 | /// Returns true if \p I is known dead. |
3168 | virtual bool isKnownDead(const Instruction *I) const = 0; |
3169 | |
3170 | /// This method is used to check if at least one instruction in a collection |
3171 | /// of instructions is live. |
3172 | template <typename T> bool isLiveInstSet(T begin, T end) const { |
3173 | for (const auto &I : llvm::make_range(begin, end)) { |
3174 | assert(I->getFunction() == getIRPosition().getAssociatedFunction() &&((void)0) |
3175 | "Instruction must be in the same anchor scope function.")((void)0); |
3176 | |
3177 | if (!isAssumedDead(I)) |
3178 | return true; |
3179 | } |
3180 | |
3181 | return false; |
3182 | } |
3183 | |
3184 | public: |
3185 | /// Create an abstract attribute view for the position \p IRP. |
3186 | static AAIsDead &createForPosition(const IRPosition &IRP, Attributor &A); |
3187 | |
3188 | /// Determine if \p F might catch asynchronous exceptions. |
3189 | static bool mayCatchAsynchronousExceptions(const Function &F) { |
3190 | return F.hasPersonalityFn() && !canSimplifyInvokeNoUnwind(&F); |
3191 | } |
3192 | |
3193 | /// Return if the edge from \p From BB to \p To BB is assumed dead. |
3194 | /// This is specifically useful in AAReachability. |
3195 | virtual bool isEdgeDead(const BasicBlock *From, const BasicBlock *To) const { |
3196 | return false; |
3197 | } |
3198 | |
3199 | /// See AbstractAttribute::getName() |
3200 | const std::string getName() const override { return "AAIsDead"; } |
3201 | |
3202 | /// See AbstractAttribute::getIdAddr() |
3203 | const char *getIdAddr() const override { return &ID; } |
3204 | |
3205 | /// This function should return true if the type of the \p AA is AAIsDead |
3206 | static bool classof(const AbstractAttribute *AA) { |
3207 | return (AA->getIdAddr() == &ID); |
3208 | } |
3209 | |
3210 | /// Unique ID (due to the unique address) |
3211 | static const char ID; |
3212 | |
3213 | friend struct Attributor; |
3214 | }; |
3215 | |
3216 | /// State for dereferenceable attribute |
3217 | struct DerefState : AbstractState { |
3218 | |
3219 | static DerefState getBestState() { return DerefState(); } |
3220 | static DerefState getBestState(const DerefState &) { return getBestState(); } |
3221 | |
3222 | /// Return the worst possible representable state. |
3223 | static DerefState getWorstState() { |
3224 | DerefState DS; |
3225 | DS.indicatePessimisticFixpoint(); |
3226 | return DS; |
3227 | } |
3228 | static DerefState getWorstState(const DerefState &) { |
3229 | return getWorstState(); |
3230 | } |
3231 | |
3232 | /// State representing for dereferenceable bytes. |
3233 | IncIntegerState<> DerefBytesState; |
3234 | |
3235 | /// Map representing for accessed memory offsets and sizes. |
3236 | /// A key is Offset and a value is size. |
3237 | /// If there is a load/store instruction something like, |
3238 | /// p[offset] = v; |
3239 | /// (offset, sizeof(v)) will be inserted to this map. |
3240 | /// std::map is used because we want to iterate keys in ascending order. |
3241 | std::map<int64_t, uint64_t> AccessedBytesMap; |
3242 | |
3243 | /// Helper function to calculate dereferenceable bytes from current known |
3244 | /// bytes and accessed bytes. |
3245 | /// |
3246 | /// int f(int *A){ |
3247 | /// *A = 0; |
3248 | /// *(A+2) = 2; |
3249 | /// *(A+1) = 1; |
3250 | /// *(A+10) = 10; |
3251 | /// } |
3252 | /// ``` |
3253 | /// In that case, AccessedBytesMap is `{0:4, 4:4, 8:4, 40:4}`. |
3254 | /// AccessedBytesMap is std::map so it is iterated in accending order on |
3255 | /// key(Offset). So KnownBytes will be updated like this: |
3256 | /// |
3257 | /// |Access | KnownBytes |
3258 | /// |(0, 4)| 0 -> 4 |
3259 | /// |(4, 4)| 4 -> 8 |
3260 | /// |(8, 4)| 8 -> 12 |
3261 | /// |(40, 4) | 12 (break) |
3262 | void computeKnownDerefBytesFromAccessedMap() { |
3263 | int64_t KnownBytes = DerefBytesState.getKnown(); |
3264 | for (auto &Access : AccessedBytesMap) { |
3265 | if (KnownBytes < Access.first) |
3266 | break; |
3267 | KnownBytes = std::max(KnownBytes, Access.first + (int64_t)Access.second); |
3268 | } |
3269 | |
3270 | DerefBytesState.takeKnownMaximum(KnownBytes); |
3271 | } |
3272 | |
3273 | /// State representing that whether the value is globaly dereferenceable. |
3274 | BooleanState GlobalState; |
3275 | |
3276 | /// See AbstractState::isValidState() |
3277 | bool isValidState() const override { return DerefBytesState.isValidState(); } |
3278 | |
3279 | /// See AbstractState::isAtFixpoint() |
3280 | bool isAtFixpoint() const override { |
3281 | return !isValidState() || |
3282 | (DerefBytesState.isAtFixpoint() && GlobalState.isAtFixpoint()); |
3283 | } |
3284 | |
3285 | /// See AbstractState::indicateOptimisticFixpoint(...) |
3286 | ChangeStatus indicateOptimisticFixpoint() override { |
3287 | DerefBytesState.indicateOptimisticFixpoint(); |
3288 | GlobalState.indicateOptimisticFixpoint(); |
3289 | return ChangeStatus::UNCHANGED; |
3290 | } |
3291 | |
3292 | /// See AbstractState::indicatePessimisticFixpoint(...) |
3293 | ChangeStatus indicatePessimisticFixpoint() override { |
3294 | DerefBytesState.indicatePessimisticFixpoint(); |
3295 | GlobalState.indicatePessimisticFixpoint(); |
3296 | return ChangeStatus::CHANGED; |
3297 | } |
3298 | |
3299 | /// Update known dereferenceable bytes. |
3300 | void takeKnownDerefBytesMaximum(uint64_t Bytes) { |
3301 | DerefBytesState.takeKnownMaximum(Bytes); |
3302 | |
3303 | // Known bytes might increase. |
3304 | computeKnownDerefBytesFromAccessedMap(); |
3305 | } |
3306 | |
3307 | /// Update assumed dereferenceable bytes. |
3308 | void takeAssumedDerefBytesMinimum(uint64_t Bytes) { |
3309 | DerefBytesState.takeAssumedMinimum(Bytes); |
3310 | } |
3311 | |
3312 | /// Add accessed bytes to the map. |
3313 | void addAccessedBytes(int64_t Offset, uint64_t Size) { |
3314 | uint64_t &AccessedBytes = AccessedBytesMap[Offset]; |
3315 | AccessedBytes = std::max(AccessedBytes, Size); |
3316 | |
3317 | // Known bytes might increase. |
3318 | computeKnownDerefBytesFromAccessedMap(); |
3319 | } |
3320 | |
3321 | /// Equality for DerefState. |
3322 | bool operator==(const DerefState &R) const { |
3323 | return this->DerefBytesState == R.DerefBytesState && |
3324 | this->GlobalState == R.GlobalState; |
3325 | } |
3326 | |
3327 | /// Inequality for DerefState. |
3328 | bool operator!=(const DerefState &R) const { return !(*this == R); } |
3329 | |
3330 | /// See IntegerStateBase::operator^= |
3331 | DerefState operator^=(const DerefState &R) { |
3332 | DerefBytesState ^= R.DerefBytesState; |
3333 | GlobalState ^= R.GlobalState; |
3334 | return *this; |
3335 | } |
3336 | |
3337 | /// See IntegerStateBase::operator+= |
3338 | DerefState operator+=(const DerefState &R) { |
3339 | DerefBytesState += R.DerefBytesState; |
3340 | GlobalState += R.GlobalState; |
3341 | return *this; |
3342 | } |
3343 | |
3344 | /// See IntegerStateBase::operator&= |
3345 | DerefState operator&=(const DerefState &R) { |
3346 | DerefBytesState &= R.DerefBytesState; |
3347 | GlobalState &= R.GlobalState; |
3348 | return *this; |
3349 | } |
3350 | |
3351 | /// See IntegerStateBase::operator|= |
3352 | DerefState operator|=(const DerefState &R) { |
3353 | DerefBytesState |= R.DerefBytesState; |
3354 | GlobalState |= R.GlobalState; |
3355 | return *this; |
3356 | } |
3357 | |
3358 | protected: |
3359 | const AANonNull *NonNullAA = nullptr; |
3360 | }; |
3361 | |
3362 | /// An abstract interface for all dereferenceable attribute. |
3363 | struct AADereferenceable |
3364 | : public IRAttribute<Attribute::Dereferenceable, |
3365 | StateWrapper<DerefState, AbstractAttribute>> { |
3366 | AADereferenceable(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3367 | |
3368 | /// Return true if we assume that the underlying value is nonnull. |
3369 | bool isAssumedNonNull() const { |
3370 | return NonNullAA && NonNullAA->isAssumedNonNull(); |
3371 | } |
3372 | |
3373 | /// Return true if we know that the underlying value is nonnull. |
3374 | bool isKnownNonNull() const { |
3375 | return NonNullAA && NonNullAA->isKnownNonNull(); |
3376 | } |
3377 | |
3378 | /// Return true if we assume that underlying value is |
3379 | /// dereferenceable(_or_null) globally. |
3380 | bool isAssumedGlobal() const { return GlobalState.getAssumed(); } |
3381 | |
3382 | /// Return true if we know that underlying value is |
3383 | /// dereferenceable(_or_null) globally. |
3384 | bool isKnownGlobal() const { return GlobalState.getKnown(); } |
3385 | |
3386 | /// Return assumed dereferenceable bytes. |
3387 | uint32_t getAssumedDereferenceableBytes() const { |
3388 | return DerefBytesState.getAssumed(); |
3389 | } |
3390 | |
3391 | /// Return known dereferenceable bytes. |
3392 | uint32_t getKnownDereferenceableBytes() const { |
3393 | return DerefBytesState.getKnown(); |
3394 | } |
3395 | |
3396 | /// Create an abstract attribute view for the position \p IRP. |
3397 | static AADereferenceable &createForPosition(const IRPosition &IRP, |
3398 | Attributor &A); |
3399 | |
3400 | /// See AbstractAttribute::getName() |
3401 | const std::string getName() const override { return "AADereferenceable"; } |
3402 | |
3403 | /// See AbstractAttribute::getIdAddr() |
3404 | const char *getIdAddr() const override { return &ID; } |
3405 | |
3406 | /// This function should return true if the type of the \p AA is |
3407 | /// AADereferenceable |
3408 | static bool classof(const AbstractAttribute *AA) { |
3409 | return (AA->getIdAddr() == &ID); |
3410 | } |
3411 | |
3412 | /// Unique ID (due to the unique address) |
3413 | static const char ID; |
3414 | }; |
3415 | |
3416 | using AAAlignmentStateType = |
3417 | IncIntegerState<uint32_t, Value::MaximumAlignment, 1>; |
3418 | /// An abstract interface for all align attributes. |
3419 | struct AAAlign : public IRAttribute< |
3420 | Attribute::Alignment, |
3421 | StateWrapper<AAAlignmentStateType, AbstractAttribute>> { |
3422 | AAAlign(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3423 | |
3424 | /// Return assumed alignment. |
3425 | unsigned getAssumedAlign() const { return getAssumed(); } |
3426 | |
3427 | /// Return known alignment. |
3428 | unsigned getKnownAlign() const { return getKnown(); } |
3429 | |
3430 | /// See AbstractAttribute::getName() |
3431 | const std::string getName() const override { return "AAAlign"; } |
3432 | |
3433 | /// See AbstractAttribute::getIdAddr() |
3434 | const char *getIdAddr() const override { return &ID; } |
3435 | |
3436 | /// This function should return true if the type of the \p AA is AAAlign |
3437 | static bool classof(const AbstractAttribute *AA) { |
3438 | return (AA->getIdAddr() == &ID); |
3439 | } |
3440 | |
3441 | /// Create an abstract attribute view for the position \p IRP. |
3442 | static AAAlign &createForPosition(const IRPosition &IRP, Attributor &A); |
3443 | |
3444 | /// Unique ID (due to the unique address) |
3445 | static const char ID; |
3446 | }; |
3447 | |
3448 | /// An abstract interface for all nocapture attributes. |
3449 | struct AANoCapture |
3450 | : public IRAttribute< |
3451 | Attribute::NoCapture, |
3452 | StateWrapper<BitIntegerState<uint16_t, 7, 0>, AbstractAttribute>> { |
3453 | AANoCapture(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3454 | |
3455 | /// State encoding bits. A set bit in the state means the property holds. |
3456 | /// NO_CAPTURE is the best possible state, 0 the worst possible state. |
3457 | enum { |
3458 | NOT_CAPTURED_IN_MEM = 1 << 0, |
3459 | NOT_CAPTURED_IN_INT = 1 << 1, |
3460 | NOT_CAPTURED_IN_RET = 1 << 2, |
3461 | |
3462 | /// If we do not capture the value in memory or through integers we can only |
3463 | /// communicate it back as a derived pointer. |
3464 | NO_CAPTURE_MAYBE_RETURNED = NOT_CAPTURED_IN_MEM | NOT_CAPTURED_IN_INT, |
3465 | |
3466 | /// If we do not capture the value in memory, through integers, or as a |
3467 | /// derived pointer we know it is not captured. |
3468 | NO_CAPTURE = |
3469 | NOT_CAPTURED_IN_MEM | NOT_CAPTURED_IN_INT | NOT_CAPTURED_IN_RET, |
3470 | }; |
3471 | |
3472 | /// Return true if we know that the underlying value is not captured in its |
3473 | /// respective scope. |
3474 | bool isKnownNoCapture() const { return isKnown(NO_CAPTURE); } |
3475 | |
3476 | /// Return true if we assume that the underlying value is not captured in its |
3477 | /// respective scope. |
3478 | bool isAssumedNoCapture() const { return isAssumed(NO_CAPTURE); } |
3479 | |
3480 | /// Return true if we know that the underlying value is not captured in its |
3481 | /// respective scope but we allow it to escape through a "return". |
3482 | bool isKnownNoCaptureMaybeReturned() const { |
3483 | return isKnown(NO_CAPTURE_MAYBE_RETURNED); |
3484 | } |
3485 | |
3486 | /// Return true if we assume that the underlying value is not captured in its |
3487 | /// respective scope but we allow it to escape through a "return". |
3488 | bool isAssumedNoCaptureMaybeReturned() const { |
3489 | return isAssumed(NO_CAPTURE_MAYBE_RETURNED); |
3490 | } |
3491 | |
3492 | /// Create an abstract attribute view for the position \p IRP. |
3493 | static AANoCapture &createForPosition(const IRPosition &IRP, Attributor &A); |
3494 | |
3495 | /// See AbstractAttribute::getName() |
3496 | const std::string getName() const override { return "AANoCapture"; } |
3497 | |
3498 | /// See AbstractAttribute::getIdAddr() |
3499 | const char *getIdAddr() const override { return &ID; } |
3500 | |
3501 | /// This function should return true if the type of the \p AA is AANoCapture |
3502 | static bool classof(const AbstractAttribute *AA) { |
3503 | return (AA->getIdAddr() == &ID); |
3504 | } |
3505 | |
3506 | /// Unique ID (due to the unique address) |
3507 | static const char ID; |
3508 | }; |
3509 | |
3510 | struct ValueSimplifyStateType : public AbstractState { |
3511 | |
3512 | ValueSimplifyStateType(Type *Ty) : Ty(Ty) {} |
3513 | |
3514 | static ValueSimplifyStateType getBestState(Type *Ty) { |
3515 | return ValueSimplifyStateType(Ty); |
3516 | } |
3517 | static ValueSimplifyStateType getBestState(const ValueSimplifyStateType &VS) { |
3518 | return getBestState(VS.Ty); |
3519 | } |
3520 | |
3521 | /// Return the worst possible representable state. |
3522 | static ValueSimplifyStateType getWorstState(Type *Ty) { |
3523 | ValueSimplifyStateType DS(Ty); |
3524 | DS.indicatePessimisticFixpoint(); |
3525 | return DS; |
3526 | } |
3527 | static ValueSimplifyStateType |
3528 | getWorstState(const ValueSimplifyStateType &VS) { |
3529 | return getWorstState(VS.Ty); |
3530 | } |
3531 | |
3532 | /// See AbstractState::isValidState(...) |
3533 | bool isValidState() const override { return BS.isValidState(); } |
3534 | |
3535 | /// See AbstractState::isAtFixpoint(...) |
3536 | bool isAtFixpoint() const override { return BS.isAtFixpoint(); } |
3537 | |
3538 | /// Return the assumed state encoding. |
3539 | ValueSimplifyStateType getAssumed() { return *this; } |
3540 | const ValueSimplifyStateType &getAssumed() const { return *this; } |
3541 | |
3542 | /// See AbstractState::indicatePessimisticFixpoint(...) |
3543 | ChangeStatus indicatePessimisticFixpoint() override { |
3544 | return BS.indicatePessimisticFixpoint(); |
3545 | } |
3546 | |
3547 | /// See AbstractState::indicateOptimisticFixpoint(...) |
3548 | ChangeStatus indicateOptimisticFixpoint() override { |
3549 | return BS.indicateOptimisticFixpoint(); |
3550 | } |
3551 | |
3552 | /// "Clamp" this state with \p PVS. |
3553 | ValueSimplifyStateType operator^=(const ValueSimplifyStateType &VS) { |
3554 | BS ^= VS.BS; |
3555 | unionAssumed(VS.SimplifiedAssociatedValue); |
3556 | return *this; |
3557 | } |
3558 | |
3559 | bool operator==(const ValueSimplifyStateType &RHS) const { |
3560 | if (isValidState() != RHS.isValidState()) |
3561 | return false; |
3562 | if (!isValidState() && !RHS.isValidState()) |
3563 | return true; |
3564 | return SimplifiedAssociatedValue == RHS.SimplifiedAssociatedValue; |
3565 | } |
3566 | |
3567 | protected: |
3568 | /// The type of the original value. |
3569 | Type *Ty; |
3570 | |
3571 | /// Merge \p Other into the currently assumed simplified value |
3572 | bool unionAssumed(Optional<Value *> Other); |
3573 | |
3574 | /// Helper to track validity and fixpoint |
3575 | BooleanState BS; |
3576 | |
3577 | /// An assumed simplified value. Initially, it is set to Optional::None, which |
3578 | /// means that the value is not clear under current assumption. If in the |
3579 | /// pessimistic state, getAssumedSimplifiedValue doesn't return this value but |
3580 | /// returns orignal associated value. |
3581 | Optional<Value *> SimplifiedAssociatedValue; |
3582 | }; |
3583 | |
3584 | /// An abstract interface for value simplify abstract attribute. |
3585 | struct AAValueSimplify |
3586 | : public StateWrapper<ValueSimplifyStateType, AbstractAttribute, Type *> { |
3587 | using Base = StateWrapper<ValueSimplifyStateType, AbstractAttribute, Type *>; |
3588 | AAValueSimplify(const IRPosition &IRP, Attributor &A) |
3589 | : Base(IRP, IRP.getAssociatedType()) {} |
3590 | |
3591 | /// Create an abstract attribute view for the position \p IRP. |
3592 | static AAValueSimplify &createForPosition(const IRPosition &IRP, |
3593 | Attributor &A); |
3594 | |
3595 | /// See AbstractAttribute::getName() |
3596 | const std::string getName() const override { return "AAValueSimplify"; } |
3597 | |
3598 | /// See AbstractAttribute::getIdAddr() |
3599 | const char *getIdAddr() const override { return &ID; } |
3600 | |
3601 | /// This function should return true if the type of the \p AA is |
3602 | /// AAValueSimplify |
3603 | static bool classof(const AbstractAttribute *AA) { |
3604 | return (AA->getIdAddr() == &ID); |
3605 | } |
3606 | |
3607 | /// Unique ID (due to the unique address) |
3608 | static const char ID; |
3609 | |
3610 | private: |
3611 | /// Return an assumed simplified value if a single candidate is found. If |
3612 | /// there cannot be one, return original value. If it is not clear yet, return |
3613 | /// the Optional::NoneType. |
3614 | /// |
3615 | /// Use `Attributor::getAssumedSimplified` for value simplification. |
3616 | virtual Optional<Value *> getAssumedSimplifiedValue(Attributor &A) const = 0; |
3617 | |
3618 | friend struct Attributor; |
3619 | }; |
3620 | |
3621 | struct AAHeapToStack : public StateWrapper<BooleanState, AbstractAttribute> { |
3622 | using Base = StateWrapper<BooleanState, AbstractAttribute>; |
3623 | AAHeapToStack(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
3624 | |
3625 | /// Returns true if HeapToStack conversion is assumed to be possible. |
3626 | virtual bool isAssumedHeapToStack(const CallBase &CB) const = 0; |
3627 | |
3628 | /// Returns true if HeapToStack conversion is assumed and the CB is a |
3629 | /// callsite to a free operation to be removed. |
3630 | virtual bool isAssumedHeapToStackRemovedFree(CallBase &CB) const = 0; |
3631 | |
3632 | /// Create an abstract attribute view for the position \p IRP. |
3633 | static AAHeapToStack &createForPosition(const IRPosition &IRP, Attributor &A); |
3634 | |
3635 | /// See AbstractAttribute::getName() |
3636 | const std::string getName() const override { return "AAHeapToStack"; } |
3637 | |
3638 | /// See AbstractAttribute::getIdAddr() |
3639 | const char *getIdAddr() const override { return &ID; } |
3640 | |
3641 | /// This function should return true if the type of the \p AA is AAHeapToStack |
3642 | static bool classof(const AbstractAttribute *AA) { |
3643 | return (AA->getIdAddr() == &ID); |
3644 | } |
3645 | |
3646 | /// Unique ID (due to the unique address) |
3647 | static const char ID; |
3648 | }; |
3649 | |
3650 | /// An abstract interface for privatizability. |
3651 | /// |
3652 | /// A pointer is privatizable if it can be replaced by a new, private one. |
3653 | /// Privatizing pointer reduces the use count, interaction between unrelated |
3654 | /// code parts. |
3655 | /// |
3656 | /// In order for a pointer to be privatizable its value cannot be observed |
3657 | /// (=nocapture), it is (for now) not written (=readonly & noalias), we know |
3658 | /// what values are necessary to make the private copy look like the original |
3659 | /// one, and the values we need can be loaded (=dereferenceable). |
3660 | struct AAPrivatizablePtr |
3661 | : public StateWrapper<BooleanState, AbstractAttribute> { |
3662 | using Base = StateWrapper<BooleanState, AbstractAttribute>; |
3663 | AAPrivatizablePtr(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
3664 | |
3665 | /// Returns true if pointer privatization is assumed to be possible. |
3666 | bool isAssumedPrivatizablePtr() const { return getAssumed(); } |
3667 | |
3668 | /// Returns true if pointer privatization is known to be possible. |
3669 | bool isKnownPrivatizablePtr() const { return getKnown(); } |
3670 | |
3671 | /// Return the type we can choose for a private copy of the underlying |
3672 | /// value. None means it is not clear yet, nullptr means there is none. |
3673 | virtual Optional<Type *> getPrivatizableType() const = 0; |
3674 | |
3675 | /// Create an abstract attribute view for the position \p IRP. |
3676 | static AAPrivatizablePtr &createForPosition(const IRPosition &IRP, |
3677 | Attributor &A); |
3678 | |
3679 | /// See AbstractAttribute::getName() |
3680 | const std::string getName() const override { return "AAPrivatizablePtr"; } |
3681 | |
3682 | /// See AbstractAttribute::getIdAddr() |
3683 | const char *getIdAddr() const override { return &ID; } |
3684 | |
3685 | /// This function should return true if the type of the \p AA is |
3686 | /// AAPricatizablePtr |
3687 | static bool classof(const AbstractAttribute *AA) { |
3688 | return (AA->getIdAddr() == &ID); |
3689 | } |
3690 | |
3691 | /// Unique ID (due to the unique address) |
3692 | static const char ID; |
3693 | }; |
3694 | |
3695 | /// An abstract interface for memory access kind related attributes |
3696 | /// (readnone/readonly/writeonly). |
3697 | struct AAMemoryBehavior |
3698 | : public IRAttribute< |
3699 | Attribute::ReadNone, |
3700 | StateWrapper<BitIntegerState<uint8_t, 3>, AbstractAttribute>> { |
3701 | AAMemoryBehavior(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3702 | |
3703 | /// State encoding bits. A set bit in the state means the property holds. |
3704 | /// BEST_STATE is the best possible state, 0 the worst possible state. |
3705 | enum { |
3706 | NO_READS = 1 << 0, |
3707 | NO_WRITES = 1 << 1, |
3708 | NO_ACCESSES = NO_READS | NO_WRITES, |
3709 | |
3710 | BEST_STATE = NO_ACCESSES, |
3711 | }; |
3712 | static_assert(BEST_STATE == getBestState(), "Unexpected BEST_STATE value"); |
3713 | |
3714 | /// Return true if we know that the underlying value is not read or accessed |
3715 | /// in its respective scope. |
3716 | bool isKnownReadNone() const { return isKnown(NO_ACCESSES); } |
3717 | |
3718 | /// Return true if we assume that the underlying value is not read or accessed |
3719 | /// in its respective scope. |
3720 | bool isAssumedReadNone() const { return isAssumed(NO_ACCESSES); } |
3721 | |
3722 | /// Return true if we know that the underlying value is not accessed |
3723 | /// (=written) in its respective scope. |
3724 | bool isKnownReadOnly() const { return isKnown(NO_WRITES); } |
3725 | |
3726 | /// Return true if we assume that the underlying value is not accessed |
3727 | /// (=written) in its respective scope. |
3728 | bool isAssumedReadOnly() const { return isAssumed(NO_WRITES); } |
3729 | |
3730 | /// Return true if we know that the underlying value is not read in its |
3731 | /// respective scope. |
3732 | bool isKnownWriteOnly() const { return isKnown(NO_READS); } |
3733 | |
3734 | /// Return true if we assume that the underlying value is not read in its |
3735 | /// respective scope. |
3736 | bool isAssumedWriteOnly() const { return isAssumed(NO_READS); } |
3737 | |
3738 | /// Create an abstract attribute view for the position \p IRP. |
3739 | static AAMemoryBehavior &createForPosition(const IRPosition &IRP, |
3740 | Attributor &A); |
3741 | |
3742 | /// See AbstractAttribute::getName() |
3743 | const std::string getName() const override { return "AAMemoryBehavior"; } |
3744 | |
3745 | /// See AbstractAttribute::getIdAddr() |
3746 | const char *getIdAddr() const override { return &ID; } |
3747 | |
3748 | /// This function should return true if the type of the \p AA is |
3749 | /// AAMemoryBehavior |
3750 | static bool classof(const AbstractAttribute *AA) { |
3751 | return (AA->getIdAddr() == &ID); |
3752 | } |
3753 | |
3754 | /// Unique ID (due to the unique address) |
3755 | static const char ID; |
3756 | }; |
3757 | |
3758 | /// An abstract interface for all memory location attributes |
3759 | /// (readnone/argmemonly/inaccessiblememonly/inaccessibleorargmemonly). |
3760 | struct AAMemoryLocation |
3761 | : public IRAttribute< |
3762 | Attribute::ReadNone, |
3763 | StateWrapper<BitIntegerState<uint32_t, 511>, AbstractAttribute>> { |
3764 | using MemoryLocationsKind = StateType::base_t; |
3765 | |
3766 | AAMemoryLocation(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
3767 | |
3768 | /// Encoding of different locations that could be accessed by a memory |
3769 | /// access. |
3770 | enum { |
3771 | ALL_LOCATIONS = 0, |
3772 | NO_LOCAL_MEM = 1 << 0, |
3773 | NO_CONST_MEM = 1 << 1, |
3774 | NO_GLOBAL_INTERNAL_MEM = 1 << 2, |
3775 | NO_GLOBAL_EXTERNAL_MEM = 1 << 3, |
3776 | NO_GLOBAL_MEM = NO_GLOBAL_INTERNAL_MEM | NO_GLOBAL_EXTERNAL_MEM, |
3777 | NO_ARGUMENT_MEM = 1 << 4, |
3778 | NO_INACCESSIBLE_MEM = 1 << 5, |
3779 | NO_MALLOCED_MEM = 1 << 6, |
3780 | NO_UNKOWN_MEM = 1 << 7, |
3781 | NO_LOCATIONS = NO_LOCAL_MEM | NO_CONST_MEM | NO_GLOBAL_INTERNAL_MEM | |
3782 | NO_GLOBAL_EXTERNAL_MEM | NO_ARGUMENT_MEM | |
3783 | NO_INACCESSIBLE_MEM | NO_MALLOCED_MEM | NO_UNKOWN_MEM, |
3784 | |
3785 | // Helper bit to track if we gave up or not. |
3786 | VALID_STATE = NO_LOCATIONS + 1, |
3787 | |
3788 | BEST_STATE = NO_LOCATIONS | VALID_STATE, |
3789 | }; |
3790 | static_assert(BEST_STATE == getBestState(), "Unexpected BEST_STATE value"); |
3791 | |
3792 | /// Return true if we know that the associated functions has no observable |
3793 | /// accesses. |
3794 | bool isKnownReadNone() const { return isKnown(NO_LOCATIONS); } |
3795 | |
3796 | /// Return true if we assume that the associated functions has no observable |
3797 | /// accesses. |
3798 | bool isAssumedReadNone() const { |
3799 | return isAssumed(NO_LOCATIONS) | isAssumedStackOnly(); |
3800 | } |
3801 | |
3802 | /// Return true if we know that the associated functions has at most |
3803 | /// local/stack accesses. |
3804 | bool isKnowStackOnly() const { |
3805 | return isKnown(inverseLocation(NO_LOCAL_MEM, true, true)); |
3806 | } |
3807 | |
3808 | /// Return true if we assume that the associated functions has at most |
3809 | /// local/stack accesses. |
3810 | bool isAssumedStackOnly() const { |
3811 | return isAssumed(inverseLocation(NO_LOCAL_MEM, true, true)); |
3812 | } |
3813 | |
3814 | /// Return true if we know that the underlying value will only access |
3815 | /// inaccesible memory only (see Attribute::InaccessibleMemOnly). |
3816 | bool isKnownInaccessibleMemOnly() const { |
3817 | return isKnown(inverseLocation(NO_INACCESSIBLE_MEM, true, true)); |
3818 | } |
3819 | |
3820 | /// Return true if we assume that the underlying value will only access |
3821 | /// inaccesible memory only (see Attribute::InaccessibleMemOnly). |
3822 | bool isAssumedInaccessibleMemOnly() const { |
3823 | return isAssumed(inverseLocation(NO_INACCESSIBLE_MEM, true, true)); |
3824 | } |
3825 | |
3826 | /// Return true if we know that the underlying value will only access |
3827 | /// argument pointees (see Attribute::ArgMemOnly). |
3828 | bool isKnownArgMemOnly() const { |
3829 | return isKnown(inverseLocation(NO_ARGUMENT_MEM, true, true)); |
3830 | } |
3831 | |
3832 | /// Return true if we assume that the underlying value will only access |
3833 | /// argument pointees (see Attribute::ArgMemOnly). |
3834 | bool isAssumedArgMemOnly() const { |
3835 | return isAssumed(inverseLocation(NO_ARGUMENT_MEM, true, true)); |
3836 | } |
3837 | |
3838 | /// Return true if we know that the underlying value will only access |
3839 | /// inaccesible memory or argument pointees (see |
3840 | /// Attribute::InaccessibleOrArgMemOnly). |
3841 | bool isKnownInaccessibleOrArgMemOnly() const { |
3842 | return isKnown( |
3843 | inverseLocation(NO_INACCESSIBLE_MEM | NO_ARGUMENT_MEM, true, true)); |
3844 | } |
3845 | |
3846 | /// Return true if we assume that the underlying value will only access |
3847 | /// inaccesible memory or argument pointees (see |
3848 | /// Attribute::InaccessibleOrArgMemOnly). |
3849 | bool isAssumedInaccessibleOrArgMemOnly() const { |
3850 | return isAssumed( |
3851 | inverseLocation(NO_INACCESSIBLE_MEM | NO_ARGUMENT_MEM, true, true)); |
3852 | } |
3853 | |
3854 | /// Return true if the underlying value may access memory through arguement |
3855 | /// pointers of the associated function, if any. |
3856 | bool mayAccessArgMem() const { return !isAssumed(NO_ARGUMENT_MEM); } |
3857 | |
3858 | /// Return true if only the memory locations specififed by \p MLK are assumed |
3859 | /// to be accessed by the associated function. |
3860 | bool isAssumedSpecifiedMemOnly(MemoryLocationsKind MLK) const { |
3861 | return isAssumed(MLK); |
3862 | } |
3863 | |
3864 | /// Return the locations that are assumed to be not accessed by the associated |
3865 | /// function, if any. |
3866 | MemoryLocationsKind getAssumedNotAccessedLocation() const { |
3867 | return getAssumed(); |
3868 | } |
3869 | |
3870 | /// Return the inverse of location \p Loc, thus for NO_XXX the return |
3871 | /// describes ONLY_XXX. The flags \p AndLocalMem and \p AndConstMem determine |
3872 | /// if local (=stack) and constant memory are allowed as well. Most of the |
3873 | /// time we do want them to be included, e.g., argmemonly allows accesses via |
3874 | /// argument pointers or local or constant memory accesses. |
3875 | static MemoryLocationsKind |
3876 | inverseLocation(MemoryLocationsKind Loc, bool AndLocalMem, bool AndConstMem) { |
3877 | return NO_LOCATIONS & ~(Loc | (AndLocalMem ? NO_LOCAL_MEM : 0) | |
3878 | (AndConstMem ? NO_CONST_MEM : 0)); |
3879 | }; |
3880 | |
3881 | /// Return the locations encoded by \p MLK as a readable string. |
3882 | static std::string getMemoryLocationsAsStr(MemoryLocationsKind MLK); |
3883 | |
3884 | /// Simple enum to distinguish read/write/read-write accesses. |
3885 | enum AccessKind { |
3886 | NONE = 0, |
3887 | READ = 1 << 0, |
3888 | WRITE = 1 << 1, |
3889 | READ_WRITE = READ | WRITE, |
3890 | }; |
3891 | |
3892 | /// Check \p Pred on all accesses to the memory kinds specified by \p MLK. |
3893 | /// |
3894 | /// This method will evaluate \p Pred on all accesses (access instruction + |
3895 | /// underlying accessed memory pointer) and it will return true if \p Pred |
3896 | /// holds every time. |
3897 | virtual bool checkForAllAccessesToMemoryKind( |
3898 | function_ref<bool(const Instruction *, const Value *, AccessKind, |
3899 | MemoryLocationsKind)> |
3900 | Pred, |
3901 | MemoryLocationsKind MLK) const = 0; |
3902 | |
3903 | /// Create an abstract attribute view for the position \p IRP. |
3904 | static AAMemoryLocation &createForPosition(const IRPosition &IRP, |
3905 | Attributor &A); |
3906 | |
3907 | /// See AbstractState::getAsStr(). |
3908 | const std::string getAsStr() const override { |
3909 | return getMemoryLocationsAsStr(getAssumedNotAccessedLocation()); |
3910 | } |
3911 | |
3912 | /// See AbstractAttribute::getName() |
3913 | const std::string getName() const override { return "AAMemoryLocation"; } |
3914 | |
3915 | /// See AbstractAttribute::getIdAddr() |
3916 | const char *getIdAddr() const override { return &ID; } |
3917 | |
3918 | /// This function should return true if the type of the \p AA is |
3919 | /// AAMemoryLocation |
3920 | static bool classof(const AbstractAttribute *AA) { |
3921 | return (AA->getIdAddr() == &ID); |
3922 | } |
3923 | |
3924 | /// Unique ID (due to the unique address) |
3925 | static const char ID; |
3926 | }; |
3927 | |
3928 | /// An abstract interface for range value analysis. |
3929 | struct AAValueConstantRange |
3930 | : public StateWrapper<IntegerRangeState, AbstractAttribute, uint32_t> { |
3931 | using Base = StateWrapper<IntegerRangeState, AbstractAttribute, uint32_t>; |
3932 | AAValueConstantRange(const IRPosition &IRP, Attributor &A) |
3933 | : Base(IRP, IRP.getAssociatedType()->getIntegerBitWidth()) {} |
3934 | |
3935 | /// See AbstractAttribute::getState(...). |
3936 | IntegerRangeState &getState() override { return *this; } |
3937 | const IntegerRangeState &getState() const override { return *this; } |
3938 | |
3939 | /// Create an abstract attribute view for the position \p IRP. |
3940 | static AAValueConstantRange &createForPosition(const IRPosition &IRP, |
3941 | Attributor &A); |
3942 | |
3943 | /// Return an assumed range for the assocaited value a program point \p CtxI. |
3944 | /// If \p I is nullptr, simply return an assumed range. |
3945 | virtual ConstantRange |
3946 | getAssumedConstantRange(Attributor &A, |
3947 | const Instruction *CtxI = nullptr) const = 0; |
3948 | |
3949 | /// Return a known range for the assocaited value at a program point \p CtxI. |
3950 | /// If \p I is nullptr, simply return a known range. |
3951 | virtual ConstantRange |
3952 | getKnownConstantRange(Attributor &A, |
3953 | const Instruction *CtxI = nullptr) const = 0; |
3954 | |
3955 | /// Return an assumed constant for the assocaited value a program point \p |
3956 | /// CtxI. |
3957 | Optional<ConstantInt *> |
3958 | getAssumedConstantInt(Attributor &A, |
3959 | const Instruction *CtxI = nullptr) const { |
3960 | ConstantRange RangeV = getAssumedConstantRange(A, CtxI); |
3961 | if (auto *C = RangeV.getSingleElement()) |
3962 | return cast<ConstantInt>( |
3963 | ConstantInt::get(getAssociatedValue().getType(), *C)); |
3964 | if (RangeV.isEmptySet()) |
3965 | return llvm::None; |
3966 | return nullptr; |
3967 | } |
3968 | |
3969 | /// See AbstractAttribute::getName() |
3970 | const std::string getName() const override { return "AAValueConstantRange"; } |
3971 | |
3972 | /// See AbstractAttribute::getIdAddr() |
3973 | const char *getIdAddr() const override { return &ID; } |
3974 | |
3975 | /// This function should return true if the type of the \p AA is |
3976 | /// AAValueConstantRange |
3977 | static bool classof(const AbstractAttribute *AA) { |
3978 | return (AA->getIdAddr() == &ID); |
3979 | } |
3980 | |
3981 | /// Unique ID (due to the unique address) |
3982 | static const char ID; |
3983 | }; |
3984 | |
3985 | /// A class for a set state. |
3986 | /// The assumed boolean state indicates whether the corresponding set is full |
3987 | /// set or not. If the assumed state is false, this is the worst state. The |
3988 | /// worst state (invalid state) of set of potential values is when the set |
3989 | /// contains every possible value (i.e. we cannot in any way limit the value |
3990 | /// that the target position can take). That never happens naturally, we only |
3991 | /// force it. As for the conditions under which we force it, see |
3992 | /// AAPotentialValues. |
3993 | template <typename MemberTy, typename KeyInfo = DenseMapInfo<MemberTy>> |
3994 | struct PotentialValuesState : AbstractState { |
3995 | using SetTy = DenseSet<MemberTy, KeyInfo>; |
3996 | |
3997 | PotentialValuesState() : IsValidState(true), UndefIsContained(false) {} |
3998 | |
3999 | PotentialValuesState(bool IsValid) |
4000 | : IsValidState(IsValid), UndefIsContained(false) {} |
4001 | |
4002 | /// See AbstractState::isValidState(...) |
4003 | bool isValidState() const override { return IsValidState.isValidState(); } |
4004 | |
4005 | /// See AbstractState::isAtFixpoint(...) |
4006 | bool isAtFixpoint() const override { return IsValidState.isAtFixpoint(); } |
4007 | |
4008 | /// See AbstractState::indicatePessimisticFixpoint(...) |
4009 | ChangeStatus indicatePessimisticFixpoint() override { |
4010 | return IsValidState.indicatePessimisticFixpoint(); |
4011 | } |
4012 | |
4013 | /// See AbstractState::indicateOptimisticFixpoint(...) |
4014 | ChangeStatus indicateOptimisticFixpoint() override { |
4015 | return IsValidState.indicateOptimisticFixpoint(); |
4016 | } |
4017 | |
4018 | /// Return the assumed state |
4019 | PotentialValuesState &getAssumed() { return *this; } |
4020 | const PotentialValuesState &getAssumed() const { return *this; } |
4021 | |
4022 | /// Return this set. We should check whether this set is valid or not by |
4023 | /// isValidState() before calling this function. |
4024 | const SetTy &getAssumedSet() const { |
4025 | assert(isValidState() && "This set shoud not be used when it is invalid!")((void)0); |
4026 | return Set; |
4027 | } |
4028 | |
4029 | /// Returns whether this state contains an undef value or not. |
4030 | bool undefIsContained() const { |
4031 | assert(isValidState() && "This flag shoud not be used when it is invalid!")((void)0); |
4032 | return UndefIsContained; |
4033 | } |
4034 | |
4035 | bool operator==(const PotentialValuesState &RHS) const { |
4036 | if (isValidState() != RHS.isValidState()) |
4037 | return false; |
4038 | if (!isValidState() && !RHS.isValidState()) |
4039 | return true; |
4040 | if (undefIsContained() != RHS.undefIsContained()) |
4041 | return false; |
4042 | return Set == RHS.getAssumedSet(); |
4043 | } |
4044 | |
4045 | /// Maximum number of potential values to be tracked. |
4046 | /// This is set by -attributor-max-potential-values command line option |
4047 | static unsigned MaxPotentialValues; |
4048 | |
4049 | /// Return empty set as the best state of potential values. |
4050 | static PotentialValuesState getBestState() { |
4051 | return PotentialValuesState(true); |
4052 | } |
4053 | |
4054 | static PotentialValuesState getBestState(PotentialValuesState &PVS) { |
4055 | return getBestState(); |
4056 | } |
4057 | |
4058 | /// Return full set as the worst state of potential values. |
4059 | static PotentialValuesState getWorstState() { |
4060 | return PotentialValuesState(false); |
4061 | } |
4062 | |
4063 | /// Union assumed set with the passed value. |
4064 | void unionAssumed(const MemberTy &C) { insert(C); } |
4065 | |
4066 | /// Union assumed set with assumed set of the passed state \p PVS. |
4067 | void unionAssumed(const PotentialValuesState &PVS) { unionWith(PVS); } |
4068 | |
4069 | /// Union assumed set with an undef value. |
4070 | void unionAssumedWithUndef() { unionWithUndef(); } |
4071 | |
4072 | /// "Clamp" this state with \p PVS. |
4073 | PotentialValuesState operator^=(const PotentialValuesState &PVS) { |
4074 | IsValidState ^= PVS.IsValidState; |
4075 | unionAssumed(PVS); |
4076 | return *this; |
4077 | } |
4078 | |
4079 | PotentialValuesState operator&=(const PotentialValuesState &PVS) { |
4080 | IsValidState &= PVS.IsValidState; |
4081 | unionAssumed(PVS); |
4082 | return *this; |
4083 | } |
4084 | |
4085 | private: |
4086 | /// Check the size of this set, and invalidate when the size is no |
4087 | /// less than \p MaxPotentialValues threshold. |
4088 | void checkAndInvalidate() { |
4089 | if (Set.size() >= MaxPotentialValues) |
4090 | indicatePessimisticFixpoint(); |
4091 | else |
4092 | reduceUndefValue(); |
4093 | } |
4094 | |
4095 | /// If this state contains both undef and not undef, we can reduce |
4096 | /// undef to the not undef value. |
4097 | void reduceUndefValue() { UndefIsContained = UndefIsContained & Set.empty(); } |
4098 | |
4099 | /// Insert an element into this set. |
4100 | void insert(const MemberTy &C) { |
4101 | if (!isValidState()) |
4102 | return; |
4103 | Set.insert(C); |
4104 | checkAndInvalidate(); |
4105 | } |
4106 | |
4107 | /// Take union with R. |
4108 | void unionWith(const PotentialValuesState &R) { |
4109 | /// If this is a full set, do nothing. |
4110 | if (!isValidState()) |
4111 | return; |
4112 | /// If R is full set, change L to a full set. |
4113 | if (!R.isValidState()) { |
4114 | indicatePessimisticFixpoint(); |
4115 | return; |
4116 | } |
4117 | for (const MemberTy &C : R.Set) |
4118 | Set.insert(C); |
4119 | UndefIsContained |= R.undefIsContained(); |
4120 | checkAndInvalidate(); |
4121 | } |
4122 | |
4123 | /// Take union with an undef value. |
4124 | void unionWithUndef() { |
4125 | UndefIsContained = true; |
4126 | reduceUndefValue(); |
4127 | } |
4128 | |
4129 | /// Take intersection with R. |
4130 | void intersectWith(const PotentialValuesState &R) { |
4131 | /// If R is a full set, do nothing. |
4132 | if (!R.isValidState()) |
4133 | return; |
4134 | /// If this is a full set, change this to R. |
4135 | if (!isValidState()) { |
4136 | *this = R; |
4137 | return; |
4138 | } |
4139 | SetTy IntersectSet; |
4140 | for (const MemberTy &C : Set) { |
4141 | if (R.Set.count(C)) |
4142 | IntersectSet.insert(C); |
4143 | } |
4144 | Set = IntersectSet; |
4145 | UndefIsContained &= R.undefIsContained(); |
4146 | reduceUndefValue(); |
4147 | } |
4148 | |
4149 | /// A helper state which indicate whether this state is valid or not. |
4150 | BooleanState IsValidState; |
4151 | |
4152 | /// Container for potential values |
4153 | SetTy Set; |
4154 | |
4155 | /// Flag for undef value |
4156 | bool UndefIsContained; |
4157 | }; |
4158 | |
4159 | using PotentialConstantIntValuesState = PotentialValuesState<APInt>; |
4160 | |
4161 | raw_ostream &operator<<(raw_ostream &OS, |
4162 | const PotentialConstantIntValuesState &R); |
4163 | |
4164 | /// An abstract interface for potential values analysis. |
4165 | /// |
4166 | /// This AA collects potential values for each IR position. |
4167 | /// An assumed set of potential values is initialized with the empty set (the |
4168 | /// best state) and it will grow monotonically as we find more potential values |
4169 | /// for this position. |
4170 | /// The set might be forced to the worst state, that is, to contain every |
4171 | /// possible value for this position in 2 cases. |
4172 | /// 1. We surpassed the \p MaxPotentialValues threshold. This includes the |
4173 | /// case that this position is affected (e.g. because of an operation) by a |
4174 | /// Value that is in the worst state. |
4175 | /// 2. We tried to initialize on a Value that we cannot handle (e.g. an |
4176 | /// operator we do not currently handle). |
4177 | /// |
4178 | /// TODO: Support values other than constant integers. |
4179 | struct AAPotentialValues |
4180 | : public StateWrapper<PotentialConstantIntValuesState, AbstractAttribute> { |
4181 | using Base = StateWrapper<PotentialConstantIntValuesState, AbstractAttribute>; |
4182 | AAPotentialValues(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
4183 | |
4184 | /// See AbstractAttribute::getState(...). |
4185 | PotentialConstantIntValuesState &getState() override { return *this; } |
4186 | const PotentialConstantIntValuesState &getState() const override { |
4187 | return *this; |
4188 | } |
4189 | |
4190 | /// Create an abstract attribute view for the position \p IRP. |
4191 | static AAPotentialValues &createForPosition(const IRPosition &IRP, |
4192 | Attributor &A); |
4193 | |
4194 | /// Return assumed constant for the associated value |
4195 | Optional<ConstantInt *> |
4196 | getAssumedConstantInt(Attributor &A, |
4197 | const Instruction *CtxI = nullptr) const { |
4198 | if (!isValidState()) |
4199 | return nullptr; |
4200 | if (getAssumedSet().size() == 1) |
4201 | return cast<ConstantInt>(ConstantInt::get(getAssociatedValue().getType(), |
4202 | *(getAssumedSet().begin()))); |
4203 | if (getAssumedSet().size() == 0) { |
4204 | if (undefIsContained()) |
4205 | return cast<ConstantInt>( |
4206 | ConstantInt::get(getAssociatedValue().getType(), 0)); |
4207 | return llvm::None; |
4208 | } |
4209 | |
4210 | return nullptr; |
4211 | } |
4212 | |
4213 | /// See AbstractAttribute::getName() |
4214 | const std::string getName() const override { return "AAPotentialValues"; } |
4215 | |
4216 | /// See AbstractAttribute::getIdAddr() |
4217 | const char *getIdAddr() const override { return &ID; } |
4218 | |
4219 | /// This function should return true if the type of the \p AA is |
4220 | /// AAPotentialValues |
4221 | static bool classof(const AbstractAttribute *AA) { |
4222 | return (AA->getIdAddr() == &ID); |
4223 | } |
4224 | |
4225 | /// Unique ID (due to the unique address) |
4226 | static const char ID; |
4227 | }; |
4228 | |
4229 | /// An abstract interface for all noundef attributes. |
4230 | struct AANoUndef |
4231 | : public IRAttribute<Attribute::NoUndef, |
4232 | StateWrapper<BooleanState, AbstractAttribute>> { |
4233 | AANoUndef(const IRPosition &IRP, Attributor &A) : IRAttribute(IRP) {} |
4234 | |
4235 | /// Return true if we assume that the underlying value is noundef. |
4236 | bool isAssumedNoUndef() const { return getAssumed(); } |
4237 | |
4238 | /// Return true if we know that underlying value is noundef. |
4239 | bool isKnownNoUndef() const { return getKnown(); } |
4240 | |
4241 | /// Create an abstract attribute view for the position \p IRP. |
4242 | static AANoUndef &createForPosition(const IRPosition &IRP, Attributor &A); |
4243 | |
4244 | /// See AbstractAttribute::getName() |
4245 | const std::string getName() const override { return "AANoUndef"; } |
4246 | |
4247 | /// See AbstractAttribute::getIdAddr() |
4248 | const char *getIdAddr() const override { return &ID; } |
4249 | |
4250 | /// This function should return true if the type of the \p AA is AANoUndef |
4251 | static bool classof(const AbstractAttribute *AA) { |
4252 | return (AA->getIdAddr() == &ID); |
4253 | } |
4254 | |
4255 | /// Unique ID (due to the unique address) |
4256 | static const char ID; |
4257 | }; |
4258 | |
4259 | struct AACallGraphNode; |
4260 | struct AACallEdges; |
4261 | |
4262 | /// An Iterator for call edges, creates AACallEdges attributes in a lazy way. |
4263 | /// This iterator becomes invalid if the underlying edge list changes. |
4264 | /// So This shouldn't outlive a iteration of Attributor. |
4265 | class AACallEdgeIterator |
4266 | : public iterator_adaptor_base<AACallEdgeIterator, |
4267 | SetVector<Function *>::iterator> { |
4268 | AACallEdgeIterator(Attributor &A, SetVector<Function *>::iterator Begin) |
4269 | : iterator_adaptor_base(Begin), A(A) {} |
4270 | |
4271 | public: |
4272 | AACallGraphNode *operator*() const; |
4273 | |
4274 | private: |
4275 | Attributor &A; |
4276 | friend AACallEdges; |
4277 | friend AttributorCallGraph; |
4278 | }; |
4279 | |
4280 | struct AACallGraphNode { |
4281 | AACallGraphNode(Attributor &A) : A(A) {} |
4282 | virtual ~AACallGraphNode() {} |
4283 | |
4284 | virtual AACallEdgeIterator optimisticEdgesBegin() const = 0; |
4285 | virtual AACallEdgeIterator optimisticEdgesEnd() const = 0; |
4286 | |
4287 | /// Iterator range for exploring the call graph. |
4288 | iterator_range<AACallEdgeIterator> optimisticEdgesRange() const { |
4289 | return iterator_range<AACallEdgeIterator>(optimisticEdgesBegin(), |
4290 | optimisticEdgesEnd()); |
4291 | } |
4292 | |
4293 | protected: |
4294 | /// Reference to Attributor needed for GraphTraits implementation. |
4295 | Attributor &A; |
4296 | }; |
4297 | |
4298 | /// An abstract state for querying live call edges. |
4299 | /// This interface uses the Attributor's optimistic liveness |
4300 | /// information to compute the edges that are alive. |
4301 | struct AACallEdges : public StateWrapper<BooleanState, AbstractAttribute>, |
4302 | AACallGraphNode { |
4303 | using Base = StateWrapper<BooleanState, AbstractAttribute>; |
4304 | |
4305 | AACallEdges(const IRPosition &IRP, Attributor &A) |
4306 | : Base(IRP), AACallGraphNode(A) {} |
4307 | |
4308 | /// Get the optimistic edges. |
4309 | virtual const SetVector<Function *> &getOptimisticEdges() const = 0; |
4310 | |
4311 | /// Is there any call with a unknown callee. |
4312 | virtual bool hasUnknownCallee() const = 0; |
4313 | |
4314 | /// Is there any call with a unknown callee, excluding any inline asm. |
4315 | virtual bool hasNonAsmUnknownCallee() const = 0; |
4316 | |
4317 | /// Iterator for exploring the call graph. |
4318 | AACallEdgeIterator optimisticEdgesBegin() const override { |
4319 | return AACallEdgeIterator(A, getOptimisticEdges().begin()); |
4320 | } |
4321 | |
4322 | /// Iterator for exploring the call graph. |
4323 | AACallEdgeIterator optimisticEdgesEnd() const override { |
4324 | return AACallEdgeIterator(A, getOptimisticEdges().end()); |
4325 | } |
4326 | |
4327 | /// Create an abstract attribute view for the position \p IRP. |
4328 | static AACallEdges &createForPosition(const IRPosition &IRP, Attributor &A); |
4329 | |
4330 | /// See AbstractAttribute::getName() |
4331 | const std::string getName() const override { return "AACallEdges"; } |
4332 | |
4333 | /// See AbstractAttribute::getIdAddr() |
4334 | const char *getIdAddr() const override { return &ID; } |
4335 | |
4336 | /// This function should return true if the type of the \p AA is AACallEdges. |
4337 | static bool classof(const AbstractAttribute *AA) { |
4338 | return (AA->getIdAddr() == &ID); |
4339 | } |
4340 | |
4341 | /// Unique ID (due to the unique address) |
4342 | static const char ID; |
4343 | }; |
4344 | |
4345 | // Synthetic root node for the Attributor's internal call graph. |
4346 | struct AttributorCallGraph : public AACallGraphNode { |
4347 | AttributorCallGraph(Attributor &A) : AACallGraphNode(A) {} |
4348 | virtual ~AttributorCallGraph() {} |
4349 | |
4350 | AACallEdgeIterator optimisticEdgesBegin() const override { |
4351 | return AACallEdgeIterator(A, A.Functions.begin()); |
4352 | } |
4353 | |
4354 | AACallEdgeIterator optimisticEdgesEnd() const override { |
4355 | return AACallEdgeIterator(A, A.Functions.end()); |
4356 | } |
4357 | |
4358 | /// Force populate the entire call graph. |
4359 | void populateAll() const { |
4360 | for (const AACallGraphNode *AA : optimisticEdgesRange()) { |
4361 | // Nothing else to do here. |
4362 | (void)AA; |
4363 | } |
4364 | } |
4365 | |
4366 | void print(); |
4367 | }; |
4368 | |
4369 | template <> struct GraphTraits<AACallGraphNode *> { |
4370 | using NodeRef = AACallGraphNode *; |
4371 | using ChildIteratorType = AACallEdgeIterator; |
4372 | |
4373 | static AACallEdgeIterator child_begin(AACallGraphNode *Node) { |
4374 | return Node->optimisticEdgesBegin(); |
4375 | } |
4376 | |
4377 | static AACallEdgeIterator child_end(AACallGraphNode *Node) { |
4378 | return Node->optimisticEdgesEnd(); |
4379 | } |
4380 | }; |
4381 | |
4382 | template <> |
4383 | struct GraphTraits<AttributorCallGraph *> |
4384 | : public GraphTraits<AACallGraphNode *> { |
4385 | using nodes_iterator = AACallEdgeIterator; |
4386 | |
4387 | static AACallGraphNode *getEntryNode(AttributorCallGraph *G) { |
4388 | return static_cast<AACallGraphNode *>(G); |
4389 | } |
4390 | |
4391 | static AACallEdgeIterator nodes_begin(const AttributorCallGraph *G) { |
4392 | return G->optimisticEdgesBegin(); |
4393 | } |
4394 | |
4395 | static AACallEdgeIterator nodes_end(const AttributorCallGraph *G) { |
4396 | return G->optimisticEdgesEnd(); |
4397 | } |
4398 | }; |
4399 | |
4400 | template <> |
4401 | struct DOTGraphTraits<AttributorCallGraph *> : public DefaultDOTGraphTraits { |
4402 | DOTGraphTraits(bool Simple = false) : DefaultDOTGraphTraits(Simple) {} |
4403 | |
4404 | std::string getNodeLabel(const AACallGraphNode *Node, |
4405 | const AttributorCallGraph *Graph) { |
4406 | const AACallEdges *AACE = static_cast<const AACallEdges *>(Node); |
4407 | return AACE->getAssociatedFunction()->getName().str(); |
4408 | } |
4409 | |
4410 | static bool isNodeHidden(const AACallGraphNode *Node, |
4411 | const AttributorCallGraph *Graph) { |
4412 | // Hide the synth root. |
4413 | return static_cast<const AACallGraphNode *>(Graph) == Node; |
4414 | } |
4415 | }; |
4416 | |
4417 | struct AAExecutionDomain |
4418 | : public StateWrapper<BooleanState, AbstractAttribute> { |
4419 | using Base = StateWrapper<BooleanState, AbstractAttribute>; |
4420 | AAExecutionDomain(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
4421 | |
4422 | /// Create an abstract attribute view for the position \p IRP. |
4423 | static AAExecutionDomain &createForPosition(const IRPosition &IRP, |
4424 | Attributor &A); |
4425 | |
4426 | /// See AbstractAttribute::getName(). |
4427 | const std::string getName() const override { return "AAExecutionDomain"; } |
4428 | |
4429 | /// See AbstractAttribute::getIdAddr(). |
4430 | const char *getIdAddr() const override { return &ID; } |
4431 | |
4432 | /// Check if an instruction is executed only by the initial thread. |
4433 | virtual bool isExecutedByInitialThreadOnly(const Instruction &) const = 0; |
4434 | |
4435 | /// Check if a basic block is executed only by the initial thread. |
4436 | virtual bool isExecutedByInitialThreadOnly(const BasicBlock &) const = 0; |
4437 | |
4438 | /// This function should return true if the type of the \p AA is |
4439 | /// AAExecutionDomain. |
4440 | static bool classof(const AbstractAttribute *AA) { |
4441 | return (AA->getIdAddr() == &ID); |
4442 | } |
4443 | |
4444 | /// Unique ID (due to the unique address) |
4445 | static const char ID; |
4446 | }; |
4447 | |
4448 | /// An abstract Attribute for computing reachability between functions. |
4449 | struct AAFunctionReachability |
4450 | : public StateWrapper<BooleanState, AbstractAttribute> { |
4451 | using Base = StateWrapper<BooleanState, AbstractAttribute>; |
4452 | |
4453 | AAFunctionReachability(const IRPosition &IRP, Attributor &A) : Base(IRP) {} |
4454 | |
4455 | /// If the function represented by this possition can reach \p Fn. |
4456 | virtual bool canReach(Attributor &A, Function *Fn) const = 0; |
4457 | |
4458 | /// Create an abstract attribute view for the position \p IRP. |
4459 | static AAFunctionReachability &createForPosition(const IRPosition &IRP, |
4460 | Attributor &A); |
4461 | |
4462 | /// See AbstractAttribute::getName() |
4463 | const std::string getName() const override { return "AAFuncitonReacability"; } |
4464 | |
4465 | /// See AbstractAttribute::getIdAddr() |
4466 | const char *getIdAddr() const override { return &ID; } |
4467 | |
4468 | /// This function should return true if the type of the \p AA is AACallEdges. |
4469 | static bool classof(const AbstractAttribute *AA) { |
4470 | return (AA->getIdAddr() == &ID); |
4471 | } |
4472 | |
4473 | /// Unique ID (due to the unique address) |
4474 | static const char ID; |
4475 | |
4476 | private: |
4477 | /// Can this function reach a call with unknown calee. |
4478 | virtual bool canReachUnknownCallee() const = 0; |
4479 | }; |
4480 | |
4481 | /// An abstract interface for struct information. |
4482 | struct AAPointerInfo : public AbstractAttribute { |
4483 | AAPointerInfo(const IRPosition &IRP) : AbstractAttribute(IRP) {} |
4484 | |
4485 | enum AccessKind { |
4486 | AK_READ = 1 << 0, |
4487 | AK_WRITE = 1 << 1, |
4488 | AK_READ_WRITE = AK_READ | AK_WRITE, |
4489 | }; |
4490 | |
4491 | /// An access description. |
4492 | struct Access { |
4493 | Access(Instruction *I, Optional<Value *> Content, AccessKind Kind, Type *Ty) |
4494 | : LocalI(I), RemoteI(I), Content(Content), Kind(Kind), Ty(Ty) {} |
4495 | Access(Instruction *LocalI, Instruction *RemoteI, Optional<Value *> Content, |
4496 | AccessKind Kind, Type *Ty) |
4497 | : LocalI(LocalI), RemoteI(RemoteI), Content(Content), Kind(Kind), |
4498 | Ty(Ty) {} |
4499 | Access(const Access &Other) |
4500 | : LocalI(Other.LocalI), RemoteI(Other.RemoteI), Content(Other.Content), |
4501 | Kind(Other.Kind), Ty(Other.Ty) {} |
4502 | Access(const Access &&Other) |
4503 | : LocalI(Other.LocalI), RemoteI(Other.RemoteI), Content(Other.Content), |
4504 | Kind(Other.Kind), Ty(Other.Ty) {} |
4505 | |
4506 | Access &operator=(const Access &Other) { |
4507 | LocalI = Other.LocalI; |
4508 | RemoteI = Other.RemoteI; |
4509 | Content = Other.Content; |
4510 | Kind = Other.Kind; |
4511 | Ty = Other.Ty; |
4512 | return *this; |
4513 | } |
4514 | bool operator==(const Access &R) const { |
4515 | return LocalI == R.LocalI && RemoteI == R.RemoteI && |
4516 | Content == R.Content && Kind == R.Kind; |
4517 | } |
4518 | bool operator!=(const Access &R) const { return !(*this == R); } |
4519 | |
4520 | Access &operator&=(const Access &R) { |
4521 | assert(RemoteI == R.RemoteI && "Expected same instruction!")((void)0); |
4522 | Content = |
4523 | AA::combineOptionalValuesInAAValueLatice(Content, R.Content, Ty); |
4524 | Kind = AccessKind(Kind | R.Kind); |
4525 | return *this; |
4526 | } |
4527 | |
4528 | /// Return the access kind. |
4529 | AccessKind getKind() const { return Kind; } |
4530 | |
4531 | /// Return true if this is a read access. |
4532 | bool isRead() const { return Kind & AK_READ; } |
4533 | |
4534 | /// Return true if this is a write access. |
4535 | bool isWrite() const { return Kind & AK_WRITE; } |
4536 | |
4537 | /// Return the instruction that causes the access with respect to the local |
4538 | /// scope of the associated attribute. |
4539 | Instruction *getLocalInst() const { return LocalI; } |
4540 | |
4541 | /// Return the actual instruction that causes the access. |
4542 | Instruction *getRemoteInst() const { return RemoteI; } |
4543 | |
4544 | /// Return true if the value written is not known yet. |
4545 | bool isWrittenValueYetUndetermined() const { return !Content.hasValue(); } |
4546 | |
4547 | /// Return true if the value written cannot be determined at all. |
4548 | bool isWrittenValueUnknown() const { |
4549 | return Content.hasValue() && !*Content; |
4550 | } |
4551 | |
4552 | /// Return the type associated with the access, if known. |
4553 | Type *getType() const { return Ty; } |
4554 | |
4555 | /// Return the value writen, if any. As long as |
4556 | /// isWrittenValueYetUndetermined return true this function shall not be |
4557 | /// called. |
4558 | Value *getWrittenValue() const { return *Content; } |
4559 | |
4560 | /// Return the written value which can be `llvm::null` if it is not yet |
4561 | /// determined. |
4562 | Optional<Value *> getContent() const { return Content; } |
4563 | |
4564 | private: |
4565 | /// The instruction responsible for the access with respect to the local |
4566 | /// scope of the associated attribute. |
4567 | Instruction *LocalI; |
4568 | |
4569 | /// The instruction responsible for the access. |
4570 | Instruction *RemoteI; |
4571 | |
4572 | /// The value written, if any. `llvm::none` means "not known yet", `nullptr` |
4573 | /// cannot be determined. |
4574 | Optional<Value *> Content; |
4575 | |
4576 | /// The access kind, e.g., READ, as bitset (could be more than one). |
4577 | AccessKind Kind; |
4578 | |
4579 | /// The type of the content, thus the type read/written, can be null if not |
4580 | /// available. |
4581 | Type *Ty; |
4582 | }; |
4583 | |
4584 | /// Create an abstract attribute view for the position \p IRP. |
4585 | static AAPointerInfo &createForPosition(const IRPosition &IRP, Attributor &A); |
4586 | |
4587 | /// See AbstractAttribute::getName() |
4588 | const std::string getName() const override { return "AAPointerInfo"; } |
4589 | |
4590 | /// See AbstractAttribute::getIdAddr() |
4591 | const char *getIdAddr() const override { return &ID; } |
4592 | |
4593 | /// Call \p CB on all accesses that might interfere with \p LI and return true |
4594 | /// if all such accesses were known and the callback returned true for all of |
4595 | /// them, false otherwise. |
4596 | virtual bool forallInterferingAccesses( |
4597 | LoadInst &LI, function_ref<bool(const Access &, bool)> CB) const = 0; |
4598 | virtual bool forallInterferingAccesses( |
4599 | StoreInst &SI, function_ref<bool(const Access &, bool)> CB) const = 0; |
4600 | |
4601 | /// This function should return true if the type of the \p AA is AAPointerInfo |
4602 | static bool classof(const AbstractAttribute *AA) { |
4603 | return (AA->getIdAddr() == &ID); |
4604 | } |
4605 | |
4606 | /// Unique ID (due to the unique address) |
4607 | static const char ID; |
4608 | }; |
4609 | |
4610 | raw_ostream &operator<<(raw_ostream &, const AAPointerInfo::Access &); |
4611 | |
4612 | /// Run options, used by the pass manager. |
4613 | enum AttributorRunOption { |
4614 | NONE = 0, |
4615 | MODULE = 1 << 0, |
4616 | CGSCC = 1 << 1, |
4617 | ALL = MODULE | CGSCC |
4618 | }; |
4619 | |
4620 | } // end namespace llvm |
4621 | |
4622 | #endif // LLVM_TRANSFORMS_IPO_ATTRIBUTOR_H |
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_ |