Bug Summary

File:src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
Warning:line 262, column 10
2nd function call argument is an uninitialized value

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name InstCombineShifts.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -D PIC -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -D_RET_PROTECTOR -ret-protector -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp

→
1//===- InstCombineShifts.cpp ----------------------------------------------===//
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 the visitShl, visitLShr, and visitAShr functions.
10//
11//===----------------------------------------------------------------------===//
12
13#include "InstCombineInternal.h"
14#include "llvm/Analysis/ConstantFolding.h"
15#include "llvm/Analysis/InstructionSimplify.h"
16#include "llvm/IR/IntrinsicInst.h"
17#include "llvm/IR/PatternMatch.h"
18#include "llvm/Transforms/InstCombine/InstCombiner.h"
19using namespace llvm;
20using namespace PatternMatch;
21
22#define DEBUG_TYPE"instcombine" "instcombine"
23
24bool canTryToConstantAddTwoShiftAmounts(Value *Sh0, Value *ShAmt0, Value *Sh1,
25 Value *ShAmt1) {
26 // We have two shift amounts from two different shifts. The types of those
27 // shift amounts may not match. If that's the case let's bailout now..
28 if (ShAmt0->getType() != ShAmt1->getType())
29 return false;
30
31 // As input, we have the following pattern:
32 // Sh0 (Sh1 X, Q), K
33 // We want to rewrite that as:
34 // Sh x, (Q+K) iff (Q+K) u< bitwidth(x)
35 // While we know that originally (Q+K) would not overflow
36 // (because 2 * (N-1) u<= iN -1), we have looked past extensions of
37 // shift amounts. so it may now overflow in smaller bitwidth.
38 // To ensure that does not happen, we need to ensure that the total maximal
39 // shift amount is still representable in that smaller bit width.
40 unsigned MaximalPossibleTotalShiftAmount =
41 (Sh0->getType()->getScalarSizeInBits() - 1) +
42 (Sh1->getType()->getScalarSizeInBits() - 1);
43 APInt MaximalRepresentableShiftAmount =
44 APInt::getAllOnesValue(ShAmt0->getType()->getScalarSizeInBits());
45 return MaximalRepresentableShiftAmount.uge(MaximalPossibleTotalShiftAmount);
46}
47
48// Given pattern:
49// (x shiftopcode Q) shiftopcode K
50// we should rewrite it as
51// x shiftopcode (Q+K) iff (Q+K) u< bitwidth(x) and
52//
53// This is valid for any shift, but they must be identical, and we must be
54// careful in case we have (zext(Q)+zext(K)) and look past extensions,
55// (Q+K) must not overflow or else (Q+K) u< bitwidth(x) is bogus.
56//
57// AnalyzeForSignBitExtraction indicates that we will only analyze whether this
58// pattern has any 2 right-shifts that sum to 1 less than original bit width.
59Value *InstCombinerImpl::reassociateShiftAmtsOfTwoSameDirectionShifts(
60 BinaryOperator *Sh0, const SimplifyQuery &SQ,
61 bool AnalyzeForSignBitExtraction) {
62 // Look for a shift of some instruction, ignore zext of shift amount if any.
63 Instruction *Sh0Op0;
64 Value *ShAmt0;
65 if (!match(Sh0,
66 m_Shift(m_Instruction(Sh0Op0), m_ZExtOrSelf(m_Value(ShAmt0)))))
67 return nullptr;
68
69 // If there is a truncation between the two shifts, we must make note of it
70 // and look through it. The truncation imposes additional constraints on the
71 // transform.
72 Instruction *Sh1;
73 Value *Trunc = nullptr;
74 match(Sh0Op0,
75 m_CombineOr(m_CombineAnd(m_Trunc(m_Instruction(Sh1)), m_Value(Trunc)),
76 m_Instruction(Sh1)));
77
78 // Inner shift: (x shiftopcode ShAmt1)
79 // Like with other shift, ignore zext of shift amount if any.
80 Value *X, *ShAmt1;
81 if (!match(Sh1, m_Shift(m_Value(X), m_ZExtOrSelf(m_Value(ShAmt1)))))
82 return nullptr;
83
84 // Verify that it would be safe to try to add those two shift amounts.
85 if (!canTryToConstantAddTwoShiftAmounts(Sh0, ShAmt0, Sh1, ShAmt1))
86 return nullptr;
87
88 // We are only looking for signbit extraction if we have two right shifts.
89 bool HadTwoRightShifts = match(Sh0, m_Shr(m_Value(), m_Value())) &&
90 match(Sh1, m_Shr(m_Value(), m_Value()));
91 // ... and if it's not two right-shifts, we know the answer already.
92 if (AnalyzeForSignBitExtraction && !HadTwoRightShifts)
93 return nullptr;
94
95 // The shift opcodes must be identical, unless we are just checking whether
96 // this pattern can be interpreted as a sign-bit-extraction.
97 Instruction::BinaryOps ShiftOpcode = Sh0->getOpcode();
98 bool IdenticalShOpcodes = Sh0->getOpcode() == Sh1->getOpcode();
99 if (!IdenticalShOpcodes && !AnalyzeForSignBitExtraction)
100 return nullptr;
101
102 // If we saw truncation, we'll need to produce extra instruction,
103 // and for that one of the operands of the shift must be one-use,
104 // unless of course we don't actually plan to produce any instructions here.
105 if (Trunc && !AnalyzeForSignBitExtraction &&
106 !match(Sh0, m_c_BinOp(m_OneUse(m_Value()), m_Value())))
107 return nullptr;
108
109 // Can we fold (ShAmt0+ShAmt1) ?
110 auto *NewShAmt = dyn_cast_or_null<Constant>(
111 SimplifyAddInst(ShAmt0, ShAmt1, /*isNSW=*/false, /*isNUW=*/false,
112 SQ.getWithInstruction(Sh0)));
113 if (!NewShAmt)
114 return nullptr; // Did not simplify.
115 unsigned NewShAmtBitWidth = NewShAmt->getType()->getScalarSizeInBits();
116 unsigned XBitWidth = X->getType()->getScalarSizeInBits();
117 // Is the new shift amount smaller than the bit width of inner/new shift?
118 if (!match(NewShAmt, m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_ULT,
119 APInt(NewShAmtBitWidth, XBitWidth))))
120 return nullptr; // FIXME: could perform constant-folding.
121
122 // If there was a truncation, and we have a right-shift, we can only fold if
123 // we are left with the original sign bit. Likewise, if we were just checking
124 // that this is a sighbit extraction, this is the place to check it.
125 // FIXME: zero shift amount is also legal here, but we can't *easily* check
126 // more than one predicate so it's not really worth it.
127 if (HadTwoRightShifts && (Trunc || AnalyzeForSignBitExtraction)) {
128 // If it's not a sign bit extraction, then we're done.
129 if (!match(NewShAmt,
130 m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_EQ,
131 APInt(NewShAmtBitWidth, XBitWidth - 1))))
132 return nullptr;
133 // If it is, and that was the question, return the base value.
134 if (AnalyzeForSignBitExtraction)
135 return X;
136 }
137
138 assert(IdenticalShOpcodes && "Should not get here with different shifts.")((void)0);
139
140 // All good, we can do this fold.
141 NewShAmt = ConstantExpr::getZExtOrBitCast(NewShAmt, X->getType());
142
143 BinaryOperator *NewShift = BinaryOperator::Create(ShiftOpcode, X, NewShAmt);
144
145 // The flags can only be propagated if there wasn't a trunc.
146 if (!Trunc) {
147 // If the pattern did not involve trunc, and both of the original shifts
148 // had the same flag set, preserve the flag.
149 if (ShiftOpcode == Instruction::BinaryOps::Shl) {
150 NewShift->setHasNoUnsignedWrap(Sh0->hasNoUnsignedWrap() &&
151 Sh1->hasNoUnsignedWrap());
152 NewShift->setHasNoSignedWrap(Sh0->hasNoSignedWrap() &&
153 Sh1->hasNoSignedWrap());
154 } else {
155 NewShift->setIsExact(Sh0->isExact() && Sh1->isExact());
156 }
157 }
158
159 Instruction *Ret = NewShift;
160 if (Trunc) {
161 Builder.Insert(NewShift);
162 Ret = CastInst::Create(Instruction::Trunc, NewShift, Sh0->getType());
163 }
164
165 return Ret;
166}
167
168// If we have some pattern that leaves only some low bits set, and then performs
169// left-shift of those bits, if none of the bits that are left after the final
170// shift are modified by the mask, we can omit the mask.
171//
172// There are many variants to this pattern:
173// a) (x & ((1 << MaskShAmt) - 1)) << ShiftShAmt
174// b) (x & (~(-1 << MaskShAmt))) << ShiftShAmt
175// c) (x & (-1 >> MaskShAmt)) << ShiftShAmt
176// d) (x & ((-1 << MaskShAmt) >> MaskShAmt)) << ShiftShAmt
177// e) ((x << MaskShAmt) l>> MaskShAmt) << ShiftShAmt
178// f) ((x << MaskShAmt) a>> MaskShAmt) << ShiftShAmt
179// All these patterns can be simplified to just:
180// x << ShiftShAmt
181// iff:
182// a,b) (MaskShAmt+ShiftShAmt) u>= bitwidth(x)
183// c,d,e,f) (ShiftShAmt-MaskShAmt) s>= 0 (i.e. ShiftShAmt u>= MaskShAmt)
184static Instruction *
185dropRedundantMaskingOfLeftShiftInput(BinaryOperator *OuterShift,
186 const SimplifyQuery &Q,
187 InstCombiner::BuilderTy &Builder) {
188 assert(OuterShift->getOpcode() == Instruction::BinaryOps::Shl &&((void)0)
189 "The input must be 'shl'!")((void)0);
190
191 Value *Masked, *ShiftShAmt;
8
←
'ShiftShAmt' declared without an initial value
→
192 match(OuterShift,
193 m_Shift(m_Value(Masked), m_ZExtOrSelf(m_Value(ShiftShAmt))));
9
←
Calling 'm_Value'
→
13
←
Returning from 'm_Value'
→
14
←
Calling 'm_ZExtOrSelf<llvm::PatternMatch::bind_ty<llvm::Value>>'
→
22
←
Returning from 'm_ZExtOrSelf<llvm::PatternMatch::bind_ty<llvm::Value>>'
→
23
←
Calling 'm_Shift<llvm::PatternMatch::bind_ty<llvm::Value>, llvm::PatternMatch::match_combine_or<llvm::PatternMatch::CastClass_match<llvm::PatternMatch::bind_ty<llvm::Value>, 39>, llvm::PatternMatch::bind_ty<llvm::Value>>>'
→
25
←
Returning from 'm_Shift<llvm::PatternMatch::bind_ty<llvm::Value>, llvm::PatternMatch::match_combine_or<llvm::PatternMatch::CastClass_match<llvm::PatternMatch::bind_ty<llvm::Value>, 39>, llvm::PatternMatch::bind_ty<llvm::Value>>>'
→
194
195 // *If* there is a truncation between an outer shift and a possibly-mask,
196 // then said truncation *must* be one-use, else we can't perform the fold.
197 Value *Trunc;
198 if (match(Masked, m_CombineAnd(m_Trunc(m_Value(Masked)), m_Value(Trunc))) &&
26
←
Taking false branch
→
199 !Trunc->hasOneUse())
200 return nullptr;
201
202 Type *NarrowestTy = OuterShift->getType();
203 Type *WidestTy = Masked->getType();
204 bool HadTrunc = WidestTy != NarrowestTy;
27
←
Assuming 'WidestTy' is equal to 'NarrowestTy'
→
205
206 // The mask must be computed in a type twice as wide to ensure
207 // that no bits are lost if the sum-of-shifts is wider than the base type.
208 Type *ExtendedTy = WidestTy->getExtendedType();
209
210 Value *MaskShAmt;
211
212 // ((1 << MaskShAmt) - 1)
213 auto MaskA = m_Add(m_Shl(m_One(), m_Value(MaskShAmt)), m_AllOnes());
214 // (~(-1 << maskNbits))
215 auto MaskB = m_Xor(m_Shl(m_AllOnes(), m_Value(MaskShAmt)), m_AllOnes());
216 // (-1 >> MaskShAmt)
217 auto MaskC = m_Shr(m_AllOnes(), m_Value(MaskShAmt));
218 // ((-1 << MaskShAmt) >> MaskShAmt)
219 auto MaskD =
220 m_Shr(m_Shl(m_AllOnes(), m_Value(MaskShAmt)), m_Deferred(MaskShAmt));
221
222 Value *X;
223 Constant *NewMask;
224
225 if (match(Masked, m_c_And(m_CombineOr(MaskA, MaskB), m_Value(X)))) {
28
←
Calling 'match<llvm::Value, llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::match_combine_or<llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_one, llvm::ConstantInt>, llvm::PatternMatch::bind_ty<llvm::Value>, 25, false>, llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_all_ones, llvm::ConstantInt>, 13, false>, llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_all_ones, llvm::ConstantInt>, llvm::PatternMatch::bind_ty<llvm::Value>, 25, false>, llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_all_ones, llvm::ConstantInt>, 30, false>>, llvm::PatternMatch::bind_ty<llvm::Value>, 28, true>>'
→
36
←
Returning from 'match<llvm::Value, llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::match_combine_or<llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_one, llvm::ConstantInt>, llvm::PatternMatch::bind_ty<llvm::Value>, 25, false>, llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_all_ones, llvm::ConstantInt>, 13, false>, llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::BinaryOp_match<llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_all_ones, llvm::ConstantInt>, llvm::PatternMatch::bind_ty<llvm::Value>, 25, false>, llvm::PatternMatch::cstval_pred_ty<llvm::PatternMatch::is_all_ones, llvm::ConstantInt>, 30, false>>, llvm::PatternMatch::bind_ty<llvm::Value>, 28, true>>'
→
37
←
Taking false branch
→
226 // Peek through an optional zext of the shift amount.
227 match(MaskShAmt, m_ZExtOrSelf(m_Value(MaskShAmt)));
228
229 // Verify that it would be safe to try to add those two shift amounts.
230 if (!canTryToConstantAddTwoShiftAmounts(OuterShift, ShiftShAmt, Masked,
231 MaskShAmt))
232 return nullptr;
233
234 // Can we simplify (MaskShAmt+ShiftShAmt) ?
235 auto *SumOfShAmts = dyn_cast_or_null<Constant>(SimplifyAddInst(
236 MaskShAmt, ShiftShAmt, /*IsNSW=*/false, /*IsNUW=*/false, Q));
237 if (!SumOfShAmts)
238 return nullptr; // Did not simplify.
239 // In this pattern SumOfShAmts correlates with the number of low bits
240 // that shall remain in the root value (OuterShift).
241
242 // An extend of an undef value becomes zero because the high bits are never
243 // completely unknown. Replace the the `undef` shift amounts with final
244 // shift bitwidth to ensure that the value remains undef when creating the
245 // subsequent shift op.
246 SumOfShAmts = Constant::replaceUndefsWith(
247 SumOfShAmts, ConstantInt::get(SumOfShAmts->getType()->getScalarType(),
248 ExtendedTy->getScalarSizeInBits()));
249 auto *ExtendedSumOfShAmts = ConstantExpr::getZExt(SumOfShAmts, ExtendedTy);
250 // And compute the mask as usual: ~(-1 << (SumOfShAmts))
251 auto *ExtendedAllOnes = ConstantExpr::getAllOnesValue(ExtendedTy);
252 auto *ExtendedInvertedMask =
253 ConstantExpr::getShl(ExtendedAllOnes, ExtendedSumOfShAmts);
254 NewMask = ConstantExpr::getNot(ExtendedInvertedMask);
255 } else if (match(Masked, m_c_And(m_CombineOr(MaskC, MaskD), m_Value(X))) ||
38
←
Taking true branch
→
256 match(Masked, m_Shr(m_Shl(m_Value(X), m_Value(MaskShAmt)),
257 m_Deferred(MaskShAmt)))) {
258 // Peek through an optional zext of the shift amount.
259 match(MaskShAmt, m_ZExtOrSelf(m_Value(MaskShAmt)));
260
261 // Verify that it would be safe to try to add those two shift amounts.
262 if (!canTryToConstantAddTwoShiftAmounts(OuterShift, ShiftShAmt, Masked,
39
←
2nd function call argument is an uninitialized value
263 MaskShAmt))
264 return nullptr;
265
266 // Can we simplify (ShiftShAmt-MaskShAmt) ?
267 auto *ShAmtsDiff = dyn_cast_or_null<Constant>(SimplifySubInst(
268 ShiftShAmt, MaskShAmt, /*IsNSW=*/false, /*IsNUW=*/false, Q));
269 if (!ShAmtsDiff)
270 return nullptr; // Did not simplify.
271 // In this pattern ShAmtsDiff correlates with the number of high bits that
272 // shall be unset in the root value (OuterShift).
273
274 // An extend of an undef value becomes zero because the high bits are never
275 // completely unknown. Replace the the `undef` shift amounts with negated
276 // bitwidth of innermost shift to ensure that the value remains undef when
277 // creating the subsequent shift op.
278 unsigned WidestTyBitWidth = WidestTy->getScalarSizeInBits();
279 ShAmtsDiff = Constant::replaceUndefsWith(
280 ShAmtsDiff, ConstantInt::get(ShAmtsDiff->getType()->getScalarType(),
281 -WidestTyBitWidth));
282 auto *ExtendedNumHighBitsToClear = ConstantExpr::getZExt(
283 ConstantExpr::getSub(ConstantInt::get(ShAmtsDiff->getType(),
284 WidestTyBitWidth,
285 /*isSigned=*/false),
286 ShAmtsDiff),
287 ExtendedTy);
288 // And compute the mask as usual: (-1 l>> (NumHighBitsToClear))
289 auto *ExtendedAllOnes = ConstantExpr::getAllOnesValue(ExtendedTy);
290 NewMask =
291 ConstantExpr::getLShr(ExtendedAllOnes, ExtendedNumHighBitsToClear);
292 } else
293 return nullptr; // Don't know anything about this pattern.
294
295 NewMask = ConstantExpr::getTrunc(NewMask, NarrowestTy);
296
297 // Does this mask has any unset bits? If not then we can just not apply it.
298 bool NeedMask = !match(NewMask, m_AllOnes());
299
300 // If we need to apply a mask, there are several more restrictions we have.
301 if (NeedMask) {
302 // The old masking instruction must go away.
303 if (!Masked->hasOneUse())
304 return nullptr;
305 // The original "masking" instruction must not have been`ashr`.
306 if (match(Masked, m_AShr(m_Value(), m_Value())))
307 return nullptr;
308 }
309
310 // If we need to apply truncation, let's do it first, since we can.
311 // We have already ensured that the old truncation will go away.
312 if (HadTrunc)
313 X = Builder.CreateTrunc(X, NarrowestTy);
314
315 // No 'NUW'/'NSW'! We no longer know that we won't shift-out non-0 bits.
316 // We didn't change the Type of this outermost shift, so we can just do it.
317 auto *NewShift = BinaryOperator::Create(OuterShift->getOpcode(), X,
318 OuterShift->getOperand(1));
319 if (!NeedMask)
320 return NewShift;
321
322 Builder.Insert(NewShift);
323 return BinaryOperator::Create(Instruction::And, NewShift, NewMask);
324}
325
326/// If we have a shift-by-constant of a bitwise logic op that itself has a
327/// shift-by-constant operand with identical opcode, we may be able to convert
328/// that into 2 independent shifts followed by the logic op. This eliminates a
329/// a use of an intermediate value (reduces dependency chain).
330static Instruction *foldShiftOfShiftedLogic(BinaryOperator &I,
331 InstCombiner::BuilderTy &Builder) {
332 assert(I.isShift() && "Expected a shift as input")((void)0);
333 auto *LogicInst = dyn_cast<BinaryOperator>(I.getOperand(0));
334 if (!LogicInst || !LogicInst->isBitwiseLogicOp() || !LogicInst->hasOneUse())
335 return nullptr;
336
337 Constant *C0, *C1;
338 if (!match(I.getOperand(1), m_Constant(C1)))
339 return nullptr;
340
341 Instruction::BinaryOps ShiftOpcode = I.getOpcode();
342 Type *Ty = I.getType();
343
344 // Find a matching one-use shift by constant. The fold is not valid if the sum
345 // of the shift values equals or exceeds bitwidth.
346 // TODO: Remove the one-use check if the other logic operand (Y) is constant.
347 Value *X, *Y;
348 auto matchFirstShift = [&](Value *V) {
349 BinaryOperator *BO;
350 APInt Threshold(Ty->getScalarSizeInBits(), Ty->getScalarSizeInBits());
351 return match(V, m_BinOp(BO)) && BO->getOpcode() == ShiftOpcode &&
352 match(V, m_OneUse(m_Shift(m_Value(X), m_Constant(C0)))) &&
353 match(ConstantExpr::getAdd(C0, C1),
354 m_SpecificInt_ICMP(ICmpInst::ICMP_ULT, Threshold));
355 };
356
357 // Logic ops are commutative, so check each operand for a match.
358 if (matchFirstShift(LogicInst->getOperand(0)))
359 Y = LogicInst->getOperand(1);
360 else if (matchFirstShift(LogicInst->getOperand(1)))
361 Y = LogicInst->getOperand(0);
362 else
363 return nullptr;
364
365 // shift (logic (shift X, C0), Y), C1 -> logic (shift X, C0+C1), (shift Y, C1)
366 Constant *ShiftSumC = ConstantExpr::getAdd(C0, C1);
367 Value *NewShift1 = Builder.CreateBinOp(ShiftOpcode, X, ShiftSumC);
368 Value *NewShift2 = Builder.CreateBinOp(ShiftOpcode, Y, I.getOperand(1));
369 return BinaryOperator::Create(LogicInst->getOpcode(), NewShift1, NewShift2);
370}
371
372Instruction *InstCombinerImpl::commonShiftTransforms(BinaryOperator &I) {
373 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
374 assert(Op0->getType() == Op1->getType())((void)0);
375
376 // If the shift amount is a one-use `sext`, we can demote it to `zext`.
377 Value *Y;
378 if (match(Op1, m_OneUse(m_SExt(m_Value(Y))))) {
379 Value *NewExt = Builder.CreateZExt(Y, I.getType(), Op1->getName());
380 return BinaryOperator::Create(I.getOpcode(), Op0, NewExt);
381 }
382
383 // See if we can fold away this shift.
384 if (SimplifyDemandedInstructionBits(I))
385 return &I;
386
387 // Try to fold constant and into select arguments.
388 if (isa<Constant>(Op0))
389 if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
390 if (Instruction *R = FoldOpIntoSelect(I, SI))
391 return R;
392
393 if (Constant *CUI = dyn_cast<Constant>(Op1))
394 if (Instruction *Res = FoldShiftByConstant(Op0, CUI, I))
395 return Res;
396
397 if (auto *NewShift = cast_or_null<Instruction>(
398 reassociateShiftAmtsOfTwoSameDirectionShifts(&I, SQ)))
399 return NewShift;
400
401 // (C1 shift (A add C2)) -> (C1 shift C2) shift A)
402 // iff A and C2 are both positive.
403 Value *A;
404 Constant *C;
405 if (match(Op0, m_Constant()) && match(Op1, m_Add(m_Value(A), m_Constant(C))))
406 if (isKnownNonNegative(A, DL, 0, &AC, &I, &DT) &&
407 isKnownNonNegative(C, DL, 0, &AC, &I, &DT))
408 return BinaryOperator::Create(
409 I.getOpcode(), Builder.CreateBinOp(I.getOpcode(), Op0, C), A);
410
411 // X shift (A srem C) -> X shift (A and (C - 1)) iff C is a power of 2.
412 // Because shifts by negative values (which could occur if A were negative)
413 // are undefined.
414 if (Op1->hasOneUse() && match(Op1, m_SRem(m_Value(A), m_Constant(C))) &&
415 match(C, m_Power2())) {
416 // FIXME: Should this get moved into SimplifyDemandedBits by saying we don't
417 // demand the sign bit (and many others) here??
418 Constant *Mask = ConstantExpr::getSub(C, ConstantInt::get(I.getType(), 1));
419 Value *Rem = Builder.CreateAnd(A, Mask, Op1->getName());
420 return replaceOperand(I, 1, Rem);
421 }
422
423 if (Instruction *Logic = foldShiftOfShiftedLogic(I, Builder))
424 return Logic;
425
426 return nullptr;
427}
428
429/// Return true if we can simplify two logical (either left or right) shifts
430/// that have constant shift amounts: OuterShift (InnerShift X, C1), C2.
431static bool canEvaluateShiftedShift(unsigned OuterShAmt, bool IsOuterShl,
432 Instruction *InnerShift,
433 InstCombinerImpl &IC, Instruction *CxtI) {
434 assert(InnerShift->isLogicalShift() && "Unexpected instruction type")((void)0);
435
436 // We need constant scalar or constant splat shifts.
437 const APInt *InnerShiftConst;
438 if (!match(InnerShift->getOperand(1), m_APInt(InnerShiftConst)))
439 return false;
440
441 // Two logical shifts in the same direction:
442 // shl (shl X, C1), C2 --> shl X, C1 + C2
443 // lshr (lshr X, C1), C2 --> lshr X, C1 + C2
444 bool IsInnerShl = InnerShift->getOpcode() == Instruction::Shl;
445 if (IsInnerShl == IsOuterShl)
446 return true;
447
448 // Equal shift amounts in opposite directions become bitwise 'and':
449 // lshr (shl X, C), C --> and X, C'
450 // shl (lshr X, C), C --> and X, C'
451 if (*InnerShiftConst == OuterShAmt)
452 return true;
453
454 // If the 2nd shift is bigger than the 1st, we can fold:
455 // lshr (shl X, C1), C2 --> and (shl X, C1 - C2), C3
456 // shl (lshr X, C1), C2 --> and (lshr X, C1 - C2), C3
457 // but it isn't profitable unless we know the and'd out bits are already zero.
458 // Also, check that the inner shift is valid (less than the type width) or
459 // we'll crash trying to produce the bit mask for the 'and'.
460 unsigned TypeWidth = InnerShift->getType()->getScalarSizeInBits();
461 if (InnerShiftConst->ugt(OuterShAmt) && InnerShiftConst->ult(TypeWidth)) {
462 unsigned InnerShAmt = InnerShiftConst->getZExtValue();
463 unsigned MaskShift =
464 IsInnerShl ? TypeWidth - InnerShAmt : InnerShAmt - OuterShAmt;
465 APInt Mask = APInt::getLowBitsSet(TypeWidth, OuterShAmt) << MaskShift;
466 if (IC.MaskedValueIsZero(InnerShift->getOperand(0), Mask, 0, CxtI))
467 return true;
468 }
469
470 return false;
471}
472
473/// See if we can compute the specified value, but shifted logically to the left
474/// or right by some number of bits. This should return true if the expression
475/// can be computed for the same cost as the current expression tree. This is
476/// used to eliminate extraneous shifting from things like:
477/// %C = shl i128 %A, 64
478/// %D = shl i128 %B, 96
479/// %E = or i128 %C, %D
480/// %F = lshr i128 %E, 64
481/// where the client will ask if E can be computed shifted right by 64-bits. If
482/// this succeeds, getShiftedValue() will be called to produce the value.
483static bool canEvaluateShifted(Value *V, unsigned NumBits, bool IsLeftShift,
484 InstCombinerImpl &IC, Instruction *CxtI) {
485 // We can always evaluate constants shifted.
486 if (isa<Constant>(V))
487 return true;
488
489 Instruction *I = dyn_cast<Instruction>(V);
490 if (!I) return false;
491
492 // We can't mutate something that has multiple uses: doing so would
493 // require duplicating the instruction in general, which isn't profitable.
494 if (!I->hasOneUse()) return false;
495
496 switch (I->getOpcode()) {
497 default: return false;
498 case Instruction::And:
499 case Instruction::Or:
500 case Instruction::Xor:
501 // Bitwise operators can all arbitrarily be arbitrarily evaluated shifted.
502 return canEvaluateShifted(I->getOperand(0), NumBits, IsLeftShift, IC, I) &&
503 canEvaluateShifted(I->getOperand(1), NumBits, IsLeftShift, IC, I);
504
505 case Instruction::Shl:
506 case Instruction::LShr:
507 return canEvaluateShiftedShift(NumBits, IsLeftShift, I, IC, CxtI);
508
509 case Instruction::Select: {
510 SelectInst *SI = cast<SelectInst>(I);
511 Value *TrueVal = SI->getTrueValue();
512 Value *FalseVal = SI->getFalseValue();
513 return canEvaluateShifted(TrueVal, NumBits, IsLeftShift, IC, SI) &&
514 canEvaluateShifted(FalseVal, NumBits, IsLeftShift, IC, SI);
515 }
516 case Instruction::PHI: {
517 // We can change a phi if we can change all operands. Note that we never
518 // get into trouble with cyclic PHIs here because we only consider
519 // instructions with a single use.
520 PHINode *PN = cast<PHINode>(I);
521 for (Value *IncValue : PN->incoming_values())
522 if (!canEvaluateShifted(IncValue, NumBits, IsLeftShift, IC, PN))
523 return false;
524 return true;
525 }
526 }
527}
528
529/// Fold OuterShift (InnerShift X, C1), C2.
530/// See canEvaluateShiftedShift() for the constraints on these instructions.
531static Value *foldShiftedShift(BinaryOperator *InnerShift, unsigned OuterShAmt,
532 bool IsOuterShl,
533 InstCombiner::BuilderTy &Builder) {
534 bool IsInnerShl = InnerShift->getOpcode() == Instruction::Shl;
535 Type *ShType = InnerShift->getType();
536 unsigned TypeWidth = ShType->getScalarSizeInBits();
537
538 // We only accept shifts-by-a-constant in canEvaluateShifted().
539 const APInt *C1;
540 match(InnerShift->getOperand(1), m_APInt(C1));
541 unsigned InnerShAmt = C1->getZExtValue();
542
543 // Change the shift amount and clear the appropriate IR flags.
544 auto NewInnerShift = [&](unsigned ShAmt) {
545 InnerShift->setOperand(1, ConstantInt::get(ShType, ShAmt));
546 if (IsInnerShl) {
547 InnerShift->setHasNoUnsignedWrap(false);
548 InnerShift->setHasNoSignedWrap(false);
549 } else {
550 InnerShift->setIsExact(false);
551 }
552 return InnerShift;
553 };
554
555 // Two logical shifts in the same direction:
556 // shl (shl X, C1), C2 --> shl X, C1 + C2
557 // lshr (lshr X, C1), C2 --> lshr X, C1 + C2
558 if (IsInnerShl == IsOuterShl) {
559 // If this is an oversized composite shift, then unsigned shifts get 0.
560 if (InnerShAmt + OuterShAmt >= TypeWidth)
561 return Constant::getNullValue(ShType);
562
563 return NewInnerShift(InnerShAmt + OuterShAmt);
564 }
565
566 // Equal shift amounts in opposite directions become bitwise 'and':
567 // lshr (shl X, C), C --> and X, C'
568 // shl (lshr X, C), C --> and X, C'
569 if (InnerShAmt == OuterShAmt) {
570 APInt Mask = IsInnerShl
571 ? APInt::getLowBitsSet(TypeWidth, TypeWidth - OuterShAmt)
572 : APInt::getHighBitsSet(TypeWidth, TypeWidth - OuterShAmt);
573 Value *And = Builder.CreateAnd(InnerShift->getOperand(0),
574 ConstantInt::get(ShType, Mask));
575 if (auto *AndI = dyn_cast<Instruction>(And)) {
576 AndI->moveBefore(InnerShift);
577 AndI->takeName(InnerShift);
578 }
579 return And;
580 }
581
582 assert(InnerShAmt > OuterShAmt &&((void)0)
583 "Unexpected opposite direction logical shift pair")((void)0);
584
585 // In general, we would need an 'and' for this transform, but
586 // canEvaluateShiftedShift() guarantees that the masked-off bits are not used.
587 // lshr (shl X, C1), C2 --> shl X, C1 - C2
588 // shl (lshr X, C1), C2 --> lshr X, C1 - C2
589 return NewInnerShift(InnerShAmt - OuterShAmt);
590}
591
592/// When canEvaluateShifted() returns true for an expression, this function
593/// inserts the new computation that produces the shifted value.
594static Value *getShiftedValue(Value *V, unsigned NumBits, bool isLeftShift,
595 InstCombinerImpl &IC, const DataLayout &DL) {
596 // We can always evaluate constants shifted.
597 if (Constant *C = dyn_cast<Constant>(V)) {
598 if (isLeftShift)
599 return IC.Builder.CreateShl(C, NumBits);
600 else
601 return IC.Builder.CreateLShr(C, NumBits);
602 }
603
604 Instruction *I = cast<Instruction>(V);
605 IC.addToWorklist(I);
606
607 switch (I->getOpcode()) {
608 default: llvm_unreachable("Inconsistency with CanEvaluateShifted")__builtin_unreachable();
609 case Instruction::And:
610 case Instruction::Or:
611 case Instruction::Xor:
612 // Bitwise operators can all arbitrarily be arbitrarily evaluated shifted.
613 I->setOperand(
614 0, getShiftedValue(I->getOperand(0), NumBits, isLeftShift, IC, DL));
615 I->setOperand(
616 1, getShiftedValue(I->getOperand(1), NumBits, isLeftShift, IC, DL));
617 return I;
618
619 case Instruction::Shl:
620 case Instruction::LShr:
621 return foldShiftedShift(cast<BinaryOperator>(I), NumBits, isLeftShift,
622 IC.Builder);
623
624 case Instruction::Select:
625 I->setOperand(
626 1, getShiftedValue(I->getOperand(1), NumBits, isLeftShift, IC, DL));
627 I->setOperand(
628 2, getShiftedValue(I->getOperand(2), NumBits, isLeftShift, IC, DL));
629 return I;
630 case Instruction::PHI: {
631 // We can change a phi if we can change all operands. Note that we never
632 // get into trouble with cyclic PHIs here because we only consider
633 // instructions with a single use.
634 PHINode *PN = cast<PHINode>(I);
635 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
636 PN->setIncomingValue(i, getShiftedValue(PN->getIncomingValue(i), NumBits,
637 isLeftShift, IC, DL));
638 return PN;
639 }
640 }
641}
642
643// If this is a bitwise operator or add with a constant RHS we might be able
644// to pull it through a shift.
645static bool canShiftBinOpWithConstantRHS(BinaryOperator &Shift,
646 BinaryOperator *BO) {
647 switch (BO->getOpcode()) {
648 default:
649 return false; // Do not perform transform!
650 case Instruction::Add:
651 return Shift.getOpcode() == Instruction::Shl;
652 case Instruction::Or:
653 case Instruction::And:
654 return true;
655 case Instruction::Xor:
656 // Do not change a 'not' of logical shift because that would create a normal
657 // 'xor'. The 'not' is likely better for analysis, SCEV, and codegen.
658 return !(Shift.isLogicalShift() && match(BO, m_Not(m_Value())));
659 }
660}
661
662Instruction *InstCombinerImpl::FoldShiftByConstant(Value *Op0, Constant *Op1,
663 BinaryOperator &I) {
664 bool isLeftShift = I.getOpcode() == Instruction::Shl;
665
666 const APInt *Op1C;
667 if (!match(Op1, m_APInt(Op1C)))
668 return nullptr;
669
670 // See if we can propagate this shift into the input, this covers the trivial
671 // cast of lshr(shl(x,c1),c2) as well as other more complex cases.
672 if (I.getOpcode() != Instruction::AShr &&
673 canEvaluateShifted(Op0, Op1C->getZExtValue(), isLeftShift, *this, &I)) {
674 LLVM_DEBUG(do { } while (false)
675 dbgs() << "ICE: GetShiftedValue propagating shift through expression"do { } while (false)
676 " to eliminate shift:\n IN: "do { } while (false)
677 << *Op0 << "\n SH: " << I << "\n")do { } while (false);
678
679 return replaceInstUsesWith(
680 I, getShiftedValue(Op0, Op1C->getZExtValue(), isLeftShift, *this, DL));
681 }
682
683 // See if we can simplify any instructions used by the instruction whose sole
684 // purpose is to compute bits we don't care about.
685 Type *Ty = I.getType();
686 unsigned TypeBits = Ty->getScalarSizeInBits();
687 assert(!Op1C->uge(TypeBits) &&((void)0)
688 "Shift over the type width should have been removed already")((void)0);
689
690 if (Instruction *FoldedShift = foldBinOpIntoSelectOrPhi(I))
691 return FoldedShift;
692
693 // Fold shift2(trunc(shift1(x,c1)), c2) -> trunc(shift2(shift1(x,c1),c2))
694 if (auto *TI = dyn_cast<TruncInst>(Op0)) {
695 // If 'shift2' is an ashr, we would have to get the sign bit into a funny
696 // place. Don't try to do this transformation in this case. Also, we
697 // require that the input operand is a shift-by-constant so that we have
698 // confidence that the shifts will get folded together. We could do this
699 // xform in more cases, but it is unlikely to be profitable.
700 const APInt *TrShiftAmt;
701 if (I.isLogicalShift() &&
702 match(TI->getOperand(0), m_Shift(m_Value(), m_APInt(TrShiftAmt)))) {
703 auto *TrOp = cast<Instruction>(TI->getOperand(0));
704 Type *SrcTy = TrOp->getType();
705
706 // Okay, we'll do this xform. Make the shift of shift.
707 Constant *ShAmt = ConstantExpr::getZExt(Op1, SrcTy);
708 // (shift2 (shift1 & 0x00FF), c2)
709 Value *NSh = Builder.CreateBinOp(I.getOpcode(), TrOp, ShAmt, I.getName());
710
711 // For logical shifts, the truncation has the effect of making the high
712 // part of the register be zeros. Emulate this by inserting an AND to
713 // clear the top bits as needed. This 'and' will usually be zapped by
714 // other xforms later if dead.
715 unsigned SrcSize = SrcTy->getScalarSizeInBits();
716 Constant *MaskV =
717 ConstantInt::get(SrcTy, APInt::getLowBitsSet(SrcSize, TypeBits));
718
719 // The mask we constructed says what the trunc would do if occurring
720 // between the shifts. We want to know the effect *after* the second
721 // shift. We know that it is a logical shift by a constant, so adjust the
722 // mask as appropriate.
723 MaskV = ConstantExpr::get(I.getOpcode(), MaskV, ShAmt);
724 // shift1 & 0x00FF
725 Value *And = Builder.CreateAnd(NSh, MaskV, TI->getName());
726 // Return the value truncated to the interesting size.
727 return new TruncInst(And, Ty);
728 }
729 }
730
731 if (Op0->hasOneUse()) {
732 if (BinaryOperator *Op0BO = dyn_cast<BinaryOperator>(Op0)) {
733 // Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
734 Value *V1;
735 const APInt *CC;
736 switch (Op0BO->getOpcode()) {
737 default: break;
738 case Instruction::Add:
739 case Instruction::And:
740 case Instruction::Or:
741 case Instruction::Xor: {
742 // These operators commute.
743 // Turn (Y + (X >> C)) << C -> (X + (Y << C)) & (~0 << C)
744 if (isLeftShift && Op0BO->getOperand(1)->hasOneUse() &&
745 match(Op0BO->getOperand(1), m_Shr(m_Value(V1),
746 m_Specific(Op1)))) {
747 Value *YS = // (Y << C)
748 Builder.CreateShl(Op0BO->getOperand(0), Op1, Op0BO->getName());
749 // (X + (Y << C))
750 Value *X = Builder.CreateBinOp(Op0BO->getOpcode(), YS, V1,
751 Op0BO->getOperand(1)->getName());
752 unsigned Op1Val = Op1C->getLimitedValue(TypeBits);
753 APInt Bits = APInt::getHighBitsSet(TypeBits, TypeBits - Op1Val);
754 Constant *Mask = ConstantInt::get(Ty, Bits);
755 return BinaryOperator::CreateAnd(X, Mask);
756 }
757
758 // Turn (Y + ((X >> C) & CC)) << C -> ((X & (CC << C)) + (Y << C))
759 Value *Op0BOOp1 = Op0BO->getOperand(1);
760 if (isLeftShift && Op0BOOp1->hasOneUse() &&
761 match(Op0BOOp1, m_And(m_OneUse(m_Shr(m_Value(V1), m_Specific(Op1))),
762 m_APInt(CC)))) {
763 Value *YS = // (Y << C)
764 Builder.CreateShl(Op0BO->getOperand(0), Op1, Op0BO->getName());
765 // X & (CC << C)
766 Value *XM = Builder.CreateAnd(
767 V1, ConstantExpr::getShl(ConstantInt::get(Ty, *CC), Op1),
768 V1->getName() + ".mask");
769 return BinaryOperator::Create(Op0BO->getOpcode(), YS, XM);
770 }
771 LLVM_FALLTHROUGH[[gnu::fallthrough]];
772 }
773
774 case Instruction::Sub: {
775 // Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
776 if (isLeftShift && Op0BO->getOperand(0)->hasOneUse() &&
777 match(Op0BO->getOperand(0), m_Shr(m_Value(V1),
778 m_Specific(Op1)))) {
779 Value *YS = // (Y << C)
780 Builder.CreateShl(Op0BO->getOperand(1), Op1, Op0BO->getName());
781 // (X + (Y << C))
782 Value *X = Builder.CreateBinOp(Op0BO->getOpcode(), V1, YS,
783 Op0BO->getOperand(0)->getName());
784 unsigned Op1Val = Op1C->getLimitedValue(TypeBits);
785 APInt Bits = APInt::getHighBitsSet(TypeBits, TypeBits - Op1Val);
786 Constant *Mask = ConstantInt::get(Ty, Bits);
787 return BinaryOperator::CreateAnd(X, Mask);
788 }
789
790 // Turn (((X >> C)&CC) + Y) << C -> (X + (Y << C)) & (CC << C)
791 if (isLeftShift && Op0BO->getOperand(0)->hasOneUse() &&
792 match(Op0BO->getOperand(0),
793 m_And(m_OneUse(m_Shr(m_Value(V1), m_Specific(Op1))),
794 m_APInt(CC)))) {
795 Value *YS = // (Y << C)
796 Builder.CreateShl(Op0BO->getOperand(1), Op1, Op0BO->getName());
797 // X & (CC << C)
798 Value *XM = Builder.CreateAnd(
799 V1, ConstantExpr::getShl(ConstantInt::get(Ty, *CC), Op1),
800 V1->getName() + ".mask");
801 return BinaryOperator::Create(Op0BO->getOpcode(), XM, YS);
802 }
803
804 break;
805 }
806 }
807
808 // If the operand is a bitwise operator with a constant RHS, and the
809 // shift is the only use, we can pull it out of the shift.
810 const APInt *Op0C;
811 if (match(Op0BO->getOperand(1), m_APInt(Op0C))) {
812 if (canShiftBinOpWithConstantRHS(I, Op0BO)) {
813 Constant *NewRHS = ConstantExpr::get(I.getOpcode(),
814 cast<Constant>(Op0BO->getOperand(1)), Op1);
815
816 Value *NewShift =
817 Builder.CreateBinOp(I.getOpcode(), Op0BO->getOperand(0), Op1);
818 NewShift->takeName(Op0BO);
819
820 return BinaryOperator::Create(Op0BO->getOpcode(), NewShift,
821 NewRHS);
822 }
823 }
824
825 // If the operand is a subtract with a constant LHS, and the shift
826 // is the only use, we can pull it out of the shift.
827 // This folds (shl (sub C1, X), C2) -> (sub (C1 << C2), (shl X, C2))
828 if (isLeftShift && Op0BO->getOpcode() == Instruction::Sub &&
829 match(Op0BO->getOperand(0), m_APInt(Op0C))) {
830 Constant *NewRHS = ConstantExpr::get(I.getOpcode(),
831 cast<Constant>(Op0BO->getOperand(0)), Op1);
832
833 Value *NewShift = Builder.CreateShl(Op0BO->getOperand(1), Op1);
834 NewShift->takeName(Op0BO);
835
836 return BinaryOperator::CreateSub(NewRHS, NewShift);
837 }
838 }
839
840 // If we have a select that conditionally executes some binary operator,
841 // see if we can pull it the select and operator through the shift.
842 //
843 // For example, turning:
844 // shl (select C, (add X, C1), X), C2
845 // Into:
846 // Y = shl X, C2
847 // select C, (add Y, C1 << C2), Y
848 Value *Cond;
849 BinaryOperator *TBO;
850 Value *FalseVal;
851 if (match(Op0, m_Select(m_Value(Cond), m_OneUse(m_BinOp(TBO)),
852 m_Value(FalseVal)))) {
853 const APInt *C;
854 if (!isa<Constant>(FalseVal) && TBO->getOperand(0) == FalseVal &&
855 match(TBO->getOperand(1), m_APInt(C)) &&
856 canShiftBinOpWithConstantRHS(I, TBO)) {
857 Constant *NewRHS = ConstantExpr::get(I.getOpcode(),
858 cast<Constant>(TBO->getOperand(1)), Op1);
859
860 Value *NewShift =
861 Builder.CreateBinOp(I.getOpcode(), FalseVal, Op1);
862 Value *NewOp = Builder.CreateBinOp(TBO->getOpcode(), NewShift,
863 NewRHS);
864 return SelectInst::Create(Cond, NewOp, NewShift);
865 }
866 }
867
868 BinaryOperator *FBO;
869 Value *TrueVal;
870 if (match(Op0, m_Select(m_Value(Cond), m_Value(TrueVal),
871 m_OneUse(m_BinOp(FBO))))) {
872 const APInt *C;
873 if (!isa<Constant>(TrueVal) && FBO->getOperand(0) == TrueVal &&
874 match(FBO->getOperand(1), m_APInt(C)) &&
875 canShiftBinOpWithConstantRHS(I, FBO)) {
876 Constant *NewRHS = ConstantExpr::get(I.getOpcode(),
877 cast<Constant>(FBO->getOperand(1)), Op1);
878
879 Value *NewShift =
880 Builder.CreateBinOp(I.getOpcode(), TrueVal, Op1);
881 Value *NewOp = Builder.CreateBinOp(FBO->getOpcode(), NewShift,
882 NewRHS);
883 return SelectInst::Create(Cond, NewShift, NewOp);
884 }
885 }
886 }
887
888 return nullptr;
889}
890
891Instruction *InstCombinerImpl::visitShl(BinaryOperator &I) {
892 const SimplifyQuery Q = SQ.getWithInstruction(&I);
893
894 if (Value *V = SimplifyShlInst(I.getOperand(0), I.getOperand(1),
1
Assuming 'V' is null
→
2
←
Taking false branch
→
895 I.hasNoSignedWrap(), I.hasNoUnsignedWrap(), Q))
896 return replaceInstUsesWith(I, V);
897
898 if (Instruction *X = foldVectorBinop(I))
3
←
Assuming 'X' is null
→
4
←
Taking false branch
→
899 return X;
900
901 if (Instruction *V = commonShiftTransforms(I))
5
←
Assuming 'V' is null
→
6
←
Taking false branch
→
902 return V;
903
904 if (Instruction *V = dropRedundantMaskingOfLeftShiftInput(&I, Q, Builder))
7
←
Calling 'dropRedundantMaskingOfLeftShiftInput'
→
905 return V;
906
907 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
908 Type *Ty = I.getType();
909 unsigned BitWidth = Ty->getScalarSizeInBits();
910
911 const APInt *ShAmtAPInt;
912 if (match(Op1, m_APInt(ShAmtAPInt))) {
913 unsigned ShAmt = ShAmtAPInt->getZExtValue();
914
915 // shl (zext X), ShAmt --> zext (shl X, ShAmt)
916 // This is only valid if X would have zeros shifted out.
917 Value *X;
918 if (match(Op0, m_OneUse(m_ZExt(m_Value(X))))) {
919 unsigned SrcWidth = X->getType()->getScalarSizeInBits();
920 if (ShAmt < SrcWidth &&
921 MaskedValueIsZero(X, APInt::getHighBitsSet(SrcWidth, ShAmt), 0, &I))
922 return new ZExtInst(Builder.CreateShl(X, ShAmt), Ty);
923 }
924
925 // (X >> C) << C --> X & (-1 << C)
926 if (match(Op0, m_Shr(m_Value(X), m_Specific(Op1)))) {
927 APInt Mask(APInt::getHighBitsSet(BitWidth, BitWidth - ShAmt));
928 return BinaryOperator::CreateAnd(X, ConstantInt::get(Ty, Mask));
929 }
930
931 const APInt *ShOp1;
932 if (match(Op0, m_Exact(m_Shr(m_Value(X), m_APInt(ShOp1)))) &&
933 ShOp1->ult(BitWidth)) {
934 unsigned ShrAmt = ShOp1->getZExtValue();
935 if (ShrAmt < ShAmt) {
936 // If C1 < C2: (X >>?,exact C1) << C2 --> X << (C2 - C1)
937 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmt - ShrAmt);
938 auto *NewShl = BinaryOperator::CreateShl(X, ShiftDiff);
939 NewShl->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
940 NewShl->setHasNoSignedWrap(I.hasNoSignedWrap());
941 return NewShl;
942 }
943 if (ShrAmt > ShAmt) {
944 // If C1 > C2: (X >>?exact C1) << C2 --> X >>?exact (C1 - C2)
945 Constant *ShiftDiff = ConstantInt::get(Ty, ShrAmt - ShAmt);
946 auto *NewShr = BinaryOperator::Create(
947 cast<BinaryOperator>(Op0)->getOpcode(), X, ShiftDiff);
948 NewShr->setIsExact(true);
949 return NewShr;
950 }
951 }
952
953 if (match(Op0, m_OneUse(m_Shr(m_Value(X), m_APInt(ShOp1)))) &&
954 ShOp1->ult(BitWidth)) {
955 unsigned ShrAmt = ShOp1->getZExtValue();
956 if (ShrAmt < ShAmt) {
957 // If C1 < C2: (X >>? C1) << C2 --> X << (C2 - C1) & (-1 << C2)
958 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmt - ShrAmt);
959 auto *NewShl = BinaryOperator::CreateShl(X, ShiftDiff);
960 NewShl->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
961 NewShl->setHasNoSignedWrap(I.hasNoSignedWrap());
962 Builder.Insert(NewShl);
963 APInt Mask(APInt::getHighBitsSet(BitWidth, BitWidth - ShAmt));
964 return BinaryOperator::CreateAnd(NewShl, ConstantInt::get(Ty, Mask));
965 }
966 if (ShrAmt > ShAmt) {
967 // If C1 > C2: (X >>? C1) << C2 --> X >>? (C1 - C2) & (-1 << C2)
968 Constant *ShiftDiff = ConstantInt::get(Ty, ShrAmt - ShAmt);
969 auto *OldShr = cast<BinaryOperator>(Op0);
970 auto *NewShr =
971 BinaryOperator::Create(OldShr->getOpcode(), X, ShiftDiff);
972 NewShr->setIsExact(OldShr->isExact());
973 Builder.Insert(NewShr);
974 APInt Mask(APInt::getHighBitsSet(BitWidth, BitWidth - ShAmt));
975 return BinaryOperator::CreateAnd(NewShr, ConstantInt::get(Ty, Mask));
976 }
977 }
978
979 if (match(Op0, m_Shl(m_Value(X), m_APInt(ShOp1))) && ShOp1->ult(BitWidth)) {
980 unsigned AmtSum = ShAmt + ShOp1->getZExtValue();
981 // Oversized shifts are simplified to zero in InstSimplify.
982 if (AmtSum < BitWidth)
983 // (X << C1) << C2 --> X << (C1 + C2)
984 return BinaryOperator::CreateShl(X, ConstantInt::get(Ty, AmtSum));
985 }
986
987 // If the shifted-out value is known-zero, then this is a NUW shift.
988 if (!I.hasNoUnsignedWrap() &&
989 MaskedValueIsZero(Op0, APInt::getHighBitsSet(BitWidth, ShAmt), 0, &I)) {
990 I.setHasNoUnsignedWrap();
991 return &I;
992 }
993
994 // If the shifted-out value is all signbits, then this is a NSW shift.
995 if (!I.hasNoSignedWrap() && ComputeNumSignBits(Op0, 0, &I) > ShAmt) {
996 I.setHasNoSignedWrap();
997 return &I;
998 }
999 }
1000
1001 // Transform (x >> y) << y to x & (-1 << y)
1002 // Valid for any type of right-shift.
1003 Value *X;
1004 if (match(Op0, m_OneUse(m_Shr(m_Value(X), m_Specific(Op1))))) {
1005 Constant *AllOnes = ConstantInt::getAllOnesValue(Ty);
1006 Value *Mask = Builder.CreateShl(AllOnes, Op1);
1007 return BinaryOperator::CreateAnd(Mask, X);
1008 }
1009
1010 Constant *C1;
1011 if (match(Op1, m_Constant(C1))) {
1012 Constant *C2;
1013 Value *X;
1014 // (C2 << X) << C1 --> (C2 << C1) << X
1015 if (match(Op0, m_OneUse(m_Shl(m_Constant(C2), m_Value(X)))))
1016 return BinaryOperator::CreateShl(ConstantExpr::getShl(C2, C1), X);
1017
1018 // (X * C2) << C1 --> X * (C2 << C1)
1019 if (match(Op0, m_Mul(m_Value(X), m_Constant(C2))))
1020 return BinaryOperator::CreateMul(X, ConstantExpr::getShl(C2, C1));
1021
1022 // shl (zext i1 X), C1 --> select (X, 1 << C1, 0)
1023 if (match(Op0, m_ZExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1)) {
1024 auto *NewC = ConstantExpr::getShl(ConstantInt::get(Ty, 1), C1);
1025 return SelectInst::Create(X, NewC, ConstantInt::getNullValue(Ty));
1026 }
1027 }
1028
1029 // (1 << (C - x)) -> ((1 << C) >> x) if C is bitwidth - 1
1030 if (match(Op0, m_One()) &&
1031 match(Op1, m_Sub(m_SpecificInt(BitWidth - 1), m_Value(X))))
1032 return BinaryOperator::CreateLShr(
1033 ConstantInt::get(Ty, APInt::getSignMask(BitWidth)), X);
1034
1035 return nullptr;
1036}
1037
1038Instruction *InstCombinerImpl::visitLShr(BinaryOperator &I) {
1039 if (Value *V = SimplifyLShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
1040 SQ.getWithInstruction(&I)))
1041 return replaceInstUsesWith(I, V);
1042
1043 if (Instruction *X = foldVectorBinop(I))
1044 return X;
1045
1046 if (Instruction *R = commonShiftTransforms(I))
1047 return R;
1048
1049 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1050 Type *Ty = I.getType();
1051 const APInt *ShAmtAPInt;
1052 if (match(Op1, m_APInt(ShAmtAPInt))) {
1053 unsigned ShAmt = ShAmtAPInt->getZExtValue();
1054 unsigned BitWidth = Ty->getScalarSizeInBits();
1055 auto *II = dyn_cast<IntrinsicInst>(Op0);
1056 if (II && isPowerOf2_32(BitWidth) && Log2_32(BitWidth) == ShAmt &&
1057 (II->getIntrinsicID() == Intrinsic::ctlz ||
1058 II->getIntrinsicID() == Intrinsic::cttz ||
1059 II->getIntrinsicID() == Intrinsic::ctpop)) {
1060 // ctlz.i32(x)>>5 --> zext(x == 0)
1061 // cttz.i32(x)>>5 --> zext(x == 0)
1062 // ctpop.i32(x)>>5 --> zext(x == -1)
1063 bool IsPop = II->getIntrinsicID() == Intrinsic::ctpop;
1064 Constant *RHS = ConstantInt::getSigned(Ty, IsPop ? -1 : 0);
1065 Value *Cmp = Builder.CreateICmpEQ(II->getArgOperand(0), RHS);
1066 return new ZExtInst(Cmp, Ty);
1067 }
1068
1069 Value *X;
1070 const APInt *ShOp1;
1071 if (match(Op0, m_Shl(m_Value(X), m_APInt(ShOp1))) && ShOp1->ult(BitWidth)) {
1072 if (ShOp1->ult(ShAmt)) {
1073 unsigned ShlAmt = ShOp1->getZExtValue();
1074 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmt - ShlAmt);
1075 if (cast<BinaryOperator>(Op0)->hasNoUnsignedWrap()) {
1076 // (X <<nuw C1) >>u C2 --> X >>u (C2 - C1)
1077 auto *NewLShr = BinaryOperator::CreateLShr(X, ShiftDiff);
1078 NewLShr->setIsExact(I.isExact());
1079 return NewLShr;
1080 }
1081 // (X << C1) >>u C2 --> (X >>u (C2 - C1)) & (-1 >> C2)
1082 Value *NewLShr = Builder.CreateLShr(X, ShiftDiff, "", I.isExact());
1083 APInt Mask(APInt::getLowBitsSet(BitWidth, BitWidth - ShAmt));
1084 return BinaryOperator::CreateAnd(NewLShr, ConstantInt::get(Ty, Mask));
1085 }
1086 if (ShOp1->ugt(ShAmt)) {
1087 unsigned ShlAmt = ShOp1->getZExtValue();
1088 Constant *ShiftDiff = ConstantInt::get(Ty, ShlAmt - ShAmt);
1089 if (cast<BinaryOperator>(Op0)->hasNoUnsignedWrap()) {
1090 // (X <<nuw C1) >>u C2 --> X <<nuw (C1 - C2)
1091 auto *NewShl = BinaryOperator::CreateShl(X, ShiftDiff);
1092 NewShl->setHasNoUnsignedWrap(true);
1093 return NewShl;
1094 }
1095 // (X << C1) >>u C2 --> X << (C1 - C2) & (-1 >> C2)
1096 Value *NewShl = Builder.CreateShl(X, ShiftDiff);
1097 APInt Mask(APInt::getLowBitsSet(BitWidth, BitWidth - ShAmt));
1098 return BinaryOperator::CreateAnd(NewShl, ConstantInt::get(Ty, Mask));
1099 }
1100 assert(*ShOp1 == ShAmt)((void)0);
1101 // (X << C) >>u C --> X & (-1 >>u C)
1102 APInt Mask(APInt::getLowBitsSet(BitWidth, BitWidth - ShAmt));
1103 return BinaryOperator::CreateAnd(X, ConstantInt::get(Ty, Mask));
1104 }
1105
1106 if (match(Op0, m_OneUse(m_ZExt(m_Value(X)))) &&
1107 (!Ty->isIntegerTy() || shouldChangeType(Ty, X->getType()))) {
1108 assert(ShAmt < X->getType()->getScalarSizeInBits() &&((void)0)
1109 "Big shift not simplified to zero?")((void)0);
1110 // lshr (zext iM X to iN), C --> zext (lshr X, C) to iN
1111 Value *NewLShr = Builder.CreateLShr(X, ShAmt);
1112 return new ZExtInst(NewLShr, Ty);
1113 }
1114
1115 if (match(Op0, m_SExt(m_Value(X))) &&
1116 (!Ty->isIntegerTy() || shouldChangeType(Ty, X->getType()))) {
1117 // Are we moving the sign bit to the low bit and widening with high zeros?
1118 unsigned SrcTyBitWidth = X->getType()->getScalarSizeInBits();
1119 if (ShAmt == BitWidth - 1) {
1120 // lshr (sext i1 X to iN), N-1 --> zext X to iN
1121 if (SrcTyBitWidth == 1)
1122 return new ZExtInst(X, Ty);
1123
1124 // lshr (sext iM X to iN), N-1 --> zext (lshr X, M-1) to iN
1125 if (Op0->hasOneUse()) {
1126 Value *NewLShr = Builder.CreateLShr(X, SrcTyBitWidth - 1);
1127 return new ZExtInst(NewLShr, Ty);
1128 }
1129 }
1130
1131 // lshr (sext iM X to iN), N-M --> zext (ashr X, min(N-M, M-1)) to iN
1132 if (ShAmt == BitWidth - SrcTyBitWidth && Op0->hasOneUse()) {
1133 // The new shift amount can't be more than the narrow source type.
1134 unsigned NewShAmt = std::min(ShAmt, SrcTyBitWidth - 1);
1135 Value *AShr = Builder.CreateAShr(X, NewShAmt);
1136 return new ZExtInst(AShr, Ty);
1137 }
1138 }
1139
1140 Value *Y;
1141 if (ShAmt == BitWidth - 1) {
1142 // lshr i32 or(X,-X), 31 --> zext (X != 0)
1143 if (match(Op0, m_OneUse(m_c_Or(m_Neg(m_Value(X)), m_Deferred(X)))))
1144 return new ZExtInst(Builder.CreateIsNotNull(X), Ty);
1145
1146 // lshr i32 (X -nsw Y), 31 --> zext (X < Y)
1147 if (match(Op0, m_OneUse(m_NSWSub(m_Value(X), m_Value(Y)))))
1148 return new ZExtInst(Builder.CreateICmpSLT(X, Y), Ty);
1149
1150 // Check if a number is negative and odd:
1151 // lshr i32 (srem X, 2), 31 --> and (X >> 31), X
1152 if (match(Op0, m_OneUse(m_SRem(m_Value(X), m_SpecificInt(2))))) {
1153 Value *Signbit = Builder.CreateLShr(X, ShAmt);
1154 return BinaryOperator::CreateAnd(Signbit, X);
1155 }
1156 }
1157
1158 if (match(Op0, m_LShr(m_Value(X), m_APInt(ShOp1)))) {
1159 unsigned AmtSum = ShAmt + ShOp1->getZExtValue();
1160 // Oversized shifts are simplified to zero in InstSimplify.
1161 if (AmtSum < BitWidth)
1162 // (X >>u C1) >>u C2 --> X >>u (C1 + C2)
1163 return BinaryOperator::CreateLShr(X, ConstantInt::get(Ty, AmtSum));
1164 }
1165
1166 // Look for a "splat" mul pattern - it replicates bits across each half of
1167 // a value, so a right shift is just a mask of the low bits:
1168 // lshr i32 (mul nuw X, Pow2+1), 16 --> and X, Pow2-1
1169 // TODO: Generalize to allow more than just half-width shifts?
1170 const APInt *MulC;
1171 if (match(Op0, m_NUWMul(m_Value(X), m_APInt(MulC))) &&
1172 ShAmt * 2 == BitWidth && (*MulC - 1).isPowerOf2() &&
1173 MulC->logBase2() == ShAmt)
1174 return BinaryOperator::CreateAnd(X, ConstantInt::get(Ty, *MulC - 2));
1175
1176 // If the shifted-out value is known-zero, then this is an exact shift.
1177 if (!I.isExact() &&
1178 MaskedValueIsZero(Op0, APInt::getLowBitsSet(BitWidth, ShAmt), 0, &I)) {
1179 I.setIsExact();
1180 return &I;
1181 }
1182 }
1183
1184 // Transform (x << y) >> y to x & (-1 >> y)
1185 Value *X;
1186 if (match(Op0, m_OneUse(m_Shl(m_Value(X), m_Specific(Op1))))) {
1187 Constant *AllOnes = ConstantInt::getAllOnesValue(Ty);
1188 Value *Mask = Builder.CreateLShr(AllOnes, Op1);
1189 return BinaryOperator::CreateAnd(Mask, X);
1190 }
1191
1192 return nullptr;
1193}
1194
1195Instruction *
1196InstCombinerImpl::foldVariableSignZeroExtensionOfVariableHighBitExtract(
1197 BinaryOperator &OldAShr) {
1198 assert(OldAShr.getOpcode() == Instruction::AShr &&((void)0)
1199 "Must be called with arithmetic right-shift instruction only.")((void)0);
1200
1201 // Check that constant C is a splat of the element-wise bitwidth of V.
1202 auto BitWidthSplat = [](Constant *C, Value *V) {
1203 return match(
1204 C, m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_EQ,
1205 APInt(C->getType()->getScalarSizeInBits(),
1206 V->getType()->getScalarSizeInBits())));
1207 };
1208
1209 // It should look like variable-length sign-extension on the outside:
1210 // (Val << (bitwidth(Val)-Nbits)) a>> (bitwidth(Val)-Nbits)
1211 Value *NBits;
1212 Instruction *MaybeTrunc;
1213 Constant *C1, *C2;
1214 if (!match(&OldAShr,
1215 m_AShr(m_Shl(m_Instruction(MaybeTrunc),
1216 m_ZExtOrSelf(m_Sub(m_Constant(C1),
1217 m_ZExtOrSelf(m_Value(NBits))))),
1218 m_ZExtOrSelf(m_Sub(m_Constant(C2),
1219 m_ZExtOrSelf(m_Deferred(NBits)))))) ||
1220 !BitWidthSplat(C1, &OldAShr) || !BitWidthSplat(C2, &OldAShr))
1221 return nullptr;
1222
1223 // There may or may not be a truncation after outer two shifts.
1224 Instruction *HighBitExtract;
1225 match(MaybeTrunc, m_TruncOrSelf(m_Instruction(HighBitExtract)));
1226 bool HadTrunc = MaybeTrunc != HighBitExtract;
1227
1228 // And finally, the innermost part of the pattern must be a right-shift.
1229 Value *X, *NumLowBitsToSkip;
1230 if (!match(HighBitExtract, m_Shr(m_Value(X), m_Value(NumLowBitsToSkip))))
1231 return nullptr;
1232
1233 // Said right-shift must extract high NBits bits - C0 must be it's bitwidth.
1234 Constant *C0;
1235 if (!match(NumLowBitsToSkip,
1236 m_ZExtOrSelf(
1237 m_Sub(m_Constant(C0), m_ZExtOrSelf(m_Specific(NBits))))) ||
1238 !BitWidthSplat(C0, HighBitExtract))
1239 return nullptr;
1240
1241 // Since the NBits is identical for all shifts, if the outermost and
1242 // innermost shifts are identical, then outermost shifts are redundant.
1243 // If we had truncation, do keep it though.
1244 if (HighBitExtract->getOpcode() == OldAShr.getOpcode())
1245 return replaceInstUsesWith(OldAShr, MaybeTrunc);
1246
1247 // Else, if there was a truncation, then we need to ensure that one
1248 // instruction will go away.
1249 if (HadTrunc && !match(&OldAShr, m_c_BinOp(m_OneUse(m_Value()), m_Value())))
1250 return nullptr;
1251
1252 // Finally, bypass two innermost shifts, and perform the outermost shift on
1253 // the operands of the innermost shift.
1254 Instruction *NewAShr =
1255 BinaryOperator::Create(OldAShr.getOpcode(), X, NumLowBitsToSkip);
1256 NewAShr->copyIRFlags(HighBitExtract); // We can preserve 'exact'-ness.
1257 if (!HadTrunc)
1258 return NewAShr;
1259
1260 Builder.Insert(NewAShr);
1261 return TruncInst::CreateTruncOrBitCast(NewAShr, OldAShr.getType());
1262}
1263
1264Instruction *InstCombinerImpl::visitAShr(BinaryOperator &I) {
1265 if (Value *V = SimplifyAShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
1266 SQ.getWithInstruction(&I)))
1267 return replaceInstUsesWith(I, V);
1268
1269 if (Instruction *X = foldVectorBinop(I))
1270 return X;
1271
1272 if (Instruction *R = commonShiftTransforms(I))
1273 return R;
1274
1275 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1276 Type *Ty = I.getType();
1277 unsigned BitWidth = Ty->getScalarSizeInBits();
1278 const APInt *ShAmtAPInt;
1279 if (match(Op1, m_APInt(ShAmtAPInt)) && ShAmtAPInt->ult(BitWidth)) {
1280 unsigned ShAmt = ShAmtAPInt->getZExtValue();
1281
1282 // If the shift amount equals the difference in width of the destination
1283 // and source scalar types:
1284 // ashr (shl (zext X), C), C --> sext X
1285 Value *X;
1286 if (match(Op0, m_Shl(m_ZExt(m_Value(X)), m_Specific(Op1))) &&
1287 ShAmt == BitWidth - X->getType()->getScalarSizeInBits())
1288 return new SExtInst(X, Ty);
1289
1290 // We can't handle (X << C1) >>s C2. It shifts arbitrary bits in. However,
1291 // we can handle (X <<nsw C1) >>s C2 since it only shifts in sign bits.
1292 const APInt *ShOp1;
1293 if (match(Op0, m_NSWShl(m_Value(X), m_APInt(ShOp1))) &&
1294 ShOp1->ult(BitWidth)) {
1295 unsigned ShlAmt = ShOp1->getZExtValue();
1296 if (ShlAmt < ShAmt) {
1297 // (X <<nsw C1) >>s C2 --> X >>s (C2 - C1)
1298 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmt - ShlAmt);
1299 auto *NewAShr = BinaryOperator::CreateAShr(X, ShiftDiff);
1300 NewAShr->setIsExact(I.isExact());
1301 return NewAShr;
1302 }
1303 if (ShlAmt > ShAmt) {
1304 // (X <<nsw C1) >>s C2 --> X <<nsw (C1 - C2)
1305 Constant *ShiftDiff = ConstantInt::get(Ty, ShlAmt - ShAmt);
1306 auto *NewShl = BinaryOperator::Create(Instruction::Shl, X, ShiftDiff);
1307 NewShl->setHasNoSignedWrap(true);
1308 return NewShl;
1309 }
1310 }
1311
1312 if (match(Op0, m_AShr(m_Value(X), m_APInt(ShOp1))) &&
1313 ShOp1->ult(BitWidth)) {
1314 unsigned AmtSum = ShAmt + ShOp1->getZExtValue();
1315 // Oversized arithmetic shifts replicate the sign bit.
1316 AmtSum = std::min(AmtSum, BitWidth - 1);
1317 // (X >>s C1) >>s C2 --> X >>s (C1 + C2)
1318 return BinaryOperator::CreateAShr(X, ConstantInt::get(Ty, AmtSum));
1319 }
1320
1321 if (match(Op0, m_OneUse(m_SExt(m_Value(X)))) &&
1322 (Ty->isVectorTy() || shouldChangeType(Ty, X->getType()))) {
1323 // ashr (sext X), C --> sext (ashr X, C')
1324 Type *SrcTy = X->getType();
1325 ShAmt = std::min(ShAmt, SrcTy->getScalarSizeInBits() - 1);
1326 Value *NewSh = Builder.CreateAShr(X, ConstantInt::get(SrcTy, ShAmt));
1327 return new SExtInst(NewSh, Ty);
1328 }
1329
1330 if (ShAmt == BitWidth - 1) {
1331 // ashr i32 or(X,-X), 31 --> sext (X != 0)
1332 if (match(Op0, m_OneUse(m_c_Or(m_Neg(m_Value(X)), m_Deferred(X)))))
1333 return new SExtInst(Builder.CreateIsNotNull(X), Ty);
1334
1335 // ashr i32 (X -nsw Y), 31 --> sext (X < Y)
1336 Value *Y;
1337 if (match(Op0, m_OneUse(m_NSWSub(m_Value(X), m_Value(Y)))))
1338 return new SExtInst(Builder.CreateICmpSLT(X, Y), Ty);
1339 }
1340
1341 // If the shifted-out value is known-zero, then this is an exact shift.
1342 if (!I.isExact() &&
1343 MaskedValueIsZero(Op0, APInt::getLowBitsSet(BitWidth, ShAmt), 0, &I)) {
1344 I.setIsExact();
1345 return &I;
1346 }
1347 }
1348
1349 if (Instruction *R = foldVariableSignZeroExtensionOfVariableHighBitExtract(I))
1350 return R;
1351
1352 // See if we can turn a signed shr into an unsigned shr.
1353 if (MaskedValueIsZero(Op0, APInt::getSignMask(BitWidth), 0, &I))
1354 return BinaryOperator::CreateLShr(Op0, Op1);
1355
1356 // ashr (xor %x, -1), %y --> xor (ashr %x, %y), -1
1357 Value *X;
1358 if (match(Op0, m_OneUse(m_Not(m_Value(X))))) {
1359 // Note that we must drop 'exact'-ness of the shift!
1360 // Note that we can't keep undef's in -1 vector constant!
1361 auto *NewAShr = Builder.CreateAShr(X, Op1, Op0->getName() + ".not");
1362 return BinaryOperator::CreateNot(NewAShr);
1363 }
1364
1365 return nullptr;
1366}
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR/PatternMatch.h

1//===- PatternMatch.h - Match on the LLVM IR --------------------*- 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 provides a simple and efficient mechanism for performing general
10// tree-based pattern matches on the LLVM IR. The power of these routines is
11// that it allows you to write concise patterns that are expressive and easy to
12// understand. The other major advantage of this is that it allows you to
13// trivially capture/bind elements in the pattern to variables. For example,
14// you can do something like this:
15//
16// Value *Exp = ...
17// Value *X, *Y; ConstantInt *C1, *C2; // (X & C1) | (Y & C2)
18// if (match(Exp, m_Or(m_And(m_Value(X), m_ConstantInt(C1)),
19// m_And(m_Value(Y), m_ConstantInt(C2))))) {
20// ... Pattern is matched and variables are bound ...
21// }
22//
23// This is primarily useful to things like the instruction combiner, but can
24// also be useful for static analysis tools or code generators.
25//
26//===----------------------------------------------------------------------===//
27
28#ifndef LLVM_IR_PATTERNMATCH_H
29#define LLVM_IR_PATTERNMATCH_H
30
31#include "llvm/ADT/APFloat.h"
32#include "llvm/ADT/APInt.h"
33#include "llvm/IR/Constant.h"
34#include "llvm/IR/Constants.h"
35#include "llvm/IR/DataLayout.h"
36#include "llvm/IR/InstrTypes.h"
37#include "llvm/IR/Instruction.h"
38#include "llvm/IR/Instructions.h"
39#include "llvm/IR/IntrinsicInst.h"
40#include "llvm/IR/Intrinsics.h"
41#include "llvm/IR/Operator.h"
42#include "llvm/IR/Value.h"
43#include "llvm/Support/Casting.h"
44#include <cstdint>
45
46namespace llvm {
47namespace PatternMatch {
48
49template <typename Val, typename Pattern> bool match(Val *V, const Pattern &P) {
50 return const_cast<Pattern &>(P).match(V);
29
←
Calling 'BinaryOp_match::match'
→
34
←
Returning from 'BinaryOp_match::match'
→
35
←
Returning zero, which participates in a condition later
→
51}
52
53template <typename Pattern> bool match(ArrayRef<int> Mask, const Pattern &P) {
54 return const_cast<Pattern &>(P).match(Mask);
55}
56
57template <typename SubPattern_t> struct OneUse_match {
58 SubPattern_t SubPattern;
59
60 OneUse_match(const SubPattern_t &SP) : SubPattern(SP) {}
61
62 template <typename OpTy> bool match(OpTy *V) {
63 return V->hasOneUse() && SubPattern.match(V);
64 }
65};
66
67template <typename T> inline OneUse_match<T> m_OneUse(const T &SubPattern) {
68 return SubPattern;
69}
70
71template <typename Class> struct class_match {
72 template <typename ITy> bool match(ITy *V) { return isa<Class>(V); }
73};
74
75/// Match an arbitrary value and ignore it.
76inline class_match<Value> m_Value() { return class_match<Value>(); }
77
78/// Match an arbitrary unary operation and ignore it.
79inline class_match<UnaryOperator> m_UnOp() {
80 return class_match<UnaryOperator>();
81}
82
83/// Match an arbitrary binary operation and ignore it.
84inline class_match<BinaryOperator> m_BinOp() {
85 return class_match<BinaryOperator>();
86}
87
88/// Matches any compare instruction and ignore it.
89inline class_match<CmpInst> m_Cmp() { return class_match<CmpInst>(); }
90
91struct undef_match {
92 static bool check(const Value *V) {
93 if (isa<UndefValue>(V))
94 return true;
95
96 const auto *CA = dyn_cast<ConstantAggregate>(V);
97 if (!CA)
98 return false;
99
100 SmallPtrSet<const ConstantAggregate *, 8> Seen;
101 SmallVector<const ConstantAggregate *, 8> Worklist;
102
103 // Either UndefValue, PoisonValue, or an aggregate that only contains
104 // these is accepted by matcher.
105 // CheckValue returns false if CA cannot satisfy this constraint.
106 auto CheckValue = [&](const ConstantAggregate *CA) {
107 for (const Value *Op : CA->operand_values()) {
108 if (isa<UndefValue>(Op))
109 continue;
110
111 const auto *CA = dyn_cast<ConstantAggregate>(Op);
112 if (!CA)
113 return false;
114 if (Seen.insert(CA).second)
115 Worklist.emplace_back(CA);
116 }
117
118 return true;
119 };
120
121 if (!CheckValue(CA))
122 return false;
123
124 while (!Worklist.empty()) {
125 if (!CheckValue(Worklist.pop_back_val()))
126 return false;
127 }
128 return true;
129 }
130 template <typename ITy> bool match(ITy *V) { return check(V); }
131};
132
133/// Match an arbitrary undef constant. This matches poison as well.
134/// If this is an aggregate and contains a non-aggregate element that is
135/// neither undef nor poison, the aggregate is not matched.
136inline auto m_Undef() { return undef_match(); }
137
138/// Match an arbitrary poison constant.
139inline class_match<PoisonValue> m_Poison() { return class_match<PoisonValue>(); }
140
141/// Match an arbitrary Constant and ignore it.
142inline class_match<Constant> m_Constant() { return class_match<Constant>(); }
143
144/// Match an arbitrary ConstantInt and ignore it.
145inline class_match<ConstantInt> m_ConstantInt() {
146 return class_match<ConstantInt>();
147}
148
149/// Match an arbitrary ConstantFP and ignore it.
150inline class_match<ConstantFP> m_ConstantFP() {
151 return class_match<ConstantFP>();
152}
153
154/// Match an arbitrary ConstantExpr and ignore it.
155inline class_match<ConstantExpr> m_ConstantExpr() {
156 return class_match<ConstantExpr>();
157}
158
159/// Match an arbitrary basic block value and ignore it.
160inline class_match<BasicBlock> m_BasicBlock() {
161 return class_match<BasicBlock>();
162}
163
164/// Inverting matcher
165template <typename Ty> struct match_unless {
166 Ty M;
167
168 match_unless(const Ty &Matcher) : M(Matcher) {}
169
170 template <typename ITy> bool match(ITy *V) { return !M.match(V); }
171};
172
173/// Match if the inner matcher does *NOT* match.
174template <typename Ty> inline match_unless<Ty> m_Unless(const Ty &M) {
175 return match_unless<Ty>(M);
176}
177
178/// Matching combinators
179template <typename LTy, typename RTy> struct match_combine_or {
180 LTy L;
181 RTy R;
182
183 match_combine_or(const LTy &Left, const RTy &Right) : L(Left), R(Right) {}
184
185 template <typename ITy> bool match(ITy *V) {
186 if (L.match(V))
187 return true;
188 if (R.match(V))
189 return true;
190 return false;
191 }
192};
193
194template <typename LTy, typename RTy> struct match_combine_and {
195 LTy L;
196 RTy R;
197
198 match_combine_and(const LTy &Left, const RTy &Right) : L(Left), R(Right) {}
199
200 template <typename ITy> bool match(ITy *V) {
201 if (L.match(V))
202 if (R.match(V))
203 return true;
204 return false;
205 }
206};
207
208/// Combine two pattern matchers matching L || R
209template <typename LTy, typename RTy>
210inline match_combine_or<LTy, RTy> m_CombineOr(const LTy &L, const RTy &R) {
211 return match_combine_or<LTy, RTy>(L, R);
19
←
Returning without writing to 'L.Op.VR'
→
212}
213
214/// Combine two pattern matchers matching L && R
215template <typename LTy, typename RTy>
216inline match_combine_and<LTy, RTy> m_CombineAnd(const LTy &L, const RTy &R) {
217 return match_combine_and<LTy, RTy>(L, R);
218}
219
220struct apint_match {
221 const APInt *&Res;
222 bool AllowUndef;
223
224 apint_match(const APInt *&Res, bool AllowUndef)
225 : Res(Res), AllowUndef(AllowUndef) {}
226
227 template <typename ITy> bool match(ITy *V) {
228 if (auto *CI = dyn_cast<ConstantInt>(V)) {
229 Res = &CI->getValue();
230 return true;
231 }
232 if (V->getType()->isVectorTy())
233 if (const auto *C = dyn_cast<Constant>(V))
234 if (auto *CI = dyn_cast_or_null<ConstantInt>(
235 C->getSplatValue(AllowUndef))) {
236 Res = &CI->getValue();
237 return true;
238 }
239 return false;
240 }
241};
242// Either constexpr if or renaming ConstantFP::getValueAPF to
243// ConstantFP::getValue is needed to do it via single template
244// function for both apint/apfloat.
245struct apfloat_match {
246 const APFloat *&Res;
247 bool AllowUndef;
248
249 apfloat_match(const APFloat *&Res, bool AllowUndef)
250 : Res(Res), AllowUndef(AllowUndef) {}
251
252 template <typename ITy> bool match(ITy *V) {
253 if (auto *CI = dyn_cast<ConstantFP>(V)) {
254 Res = &CI->getValueAPF();
255 return true;
256 }
257 if (V->getType()->isVectorTy())
258 if (const auto *C = dyn_cast<Constant>(V))
259 if (auto *CI = dyn_cast_or_null<ConstantFP>(
260 C->getSplatValue(AllowUndef))) {
261 Res = &CI->getValueAPF();
262 return true;
263 }
264 return false;
265 }
266};
267
268/// Match a ConstantInt or splatted ConstantVector, binding the
269/// specified pointer to the contained APInt.
270inline apint_match m_APInt(const APInt *&Res) {
271 // Forbid undefs by default to maintain previous behavior.
272 return apint_match(Res, /* AllowUndef */ false);
273}
274
275/// Match APInt while allowing undefs in splat vector constants.
276inline apint_match m_APIntAllowUndef(const APInt *&Res) {
277 return apint_match(Res, /* AllowUndef */ true);
278}
279
280/// Match APInt while forbidding undefs in splat vector constants.
281inline apint_match m_APIntForbidUndef(const APInt *&Res) {
282 return apint_match(Res, /* AllowUndef */ false);
283}
284
285/// Match a ConstantFP or splatted ConstantVector, binding the
286/// specified pointer to the contained APFloat.
287inline apfloat_match m_APFloat(const APFloat *&Res) {
288 // Forbid undefs by default to maintain previous behavior.
289 return apfloat_match(Res, /* AllowUndef */ false);
290}
291
292/// Match APFloat while allowing undefs in splat vector constants.
293inline apfloat_match m_APFloatAllowUndef(const APFloat *&Res) {
294 return apfloat_match(Res, /* AllowUndef */ true);
295}
296
297/// Match APFloat while forbidding undefs in splat vector constants.
298inline apfloat_match m_APFloatForbidUndef(const APFloat *&Res) {
299 return apfloat_match(Res, /* AllowUndef */ false);
300}
301
302template <int64_t Val> struct constantint_match {
303 template <typename ITy> bool match(ITy *V) {
304 if (const auto *CI = dyn_cast<ConstantInt>(V)) {
305 const APInt &CIV = CI->getValue();
306 if (Val >= 0)
307 return CIV == static_cast<uint64_t>(Val);
308 // If Val is negative, and CI is shorter than it, truncate to the right
309 // number of bits. If it is larger, then we have to sign extend. Just
310 // compare their negated values.
311 return -CIV == -Val;
312 }
313 return false;
314 }
315};
316
317/// Match a ConstantInt with a specific value.
318template <int64_t Val> inline constantint_match<Val> m_ConstantInt() {
319 return constantint_match<Val>();
320}
321
322/// This helper class is used to match constant scalars, vector splats,
323/// and fixed width vectors that satisfy a specified predicate.
324/// For fixed width vector constants, undefined elements are ignored.
325template <typename Predicate, typename ConstantVal>
326struct cstval_pred_ty : public Predicate {
327 template <typename ITy> bool match(ITy *V) {
328 if (const auto *CV = dyn_cast<ConstantVal>(V))
329 return this->isValue(CV->getValue());
330 if (const auto *VTy = dyn_cast<VectorType>(V->getType())) {
331 if (const auto *C = dyn_cast<Constant>(V)) {
332 if (const auto *CV = dyn_cast_or_null<ConstantVal>(C->getSplatValue()))
333 return this->isValue(CV->getValue());
334
335 // Number of elements of a scalable vector unknown at compile time
336 auto *FVTy = dyn_cast<FixedVectorType>(VTy);
337 if (!FVTy)
338 return false;
339
340 // Non-splat vector constant: check each element for a match.
341 unsigned NumElts = FVTy->getNumElements();
342 assert(NumElts != 0 && "Constant vector with no elements?")((void)0);
343 bool HasNonUndefElements = false;
344 for (unsigned i = 0; i != NumElts; ++i) {
345 Constant *Elt = C->getAggregateElement(i);
346 if (!Elt)
347 return false;
348 if (isa<UndefValue>(Elt))
349 continue;
350 auto *CV = dyn_cast<ConstantVal>(Elt);
351 if (!CV || !this->isValue(CV->getValue()))
352 return false;
353 HasNonUndefElements = true;
354 }
355 return HasNonUndefElements;
356 }
357 }
358 return false;
359 }
360};
361
362/// specialization of cstval_pred_ty for ConstantInt
363template <typename Predicate>
364using cst_pred_ty = cstval_pred_ty<Predicate, ConstantInt>;
365
366/// specialization of cstval_pred_ty for ConstantFP
367template <typename Predicate>
368using cstfp_pred_ty = cstval_pred_ty<Predicate, ConstantFP>;
369
370/// This helper class is used to match scalar and vector constants that
371/// satisfy a specified predicate, and bind them to an APInt.
372template <typename Predicate> struct api_pred_ty : public Predicate {
373 const APInt *&Res;
374
375 api_pred_ty(const APInt *&R) : Res(R) {}
376
377 template <typename ITy> bool match(ITy *V) {
378 if (const auto *CI = dyn_cast<ConstantInt>(V))
379 if (this->isValue(CI->getValue())) {
380 Res = &CI->getValue();
381 return true;
382 }
383 if (V->getType()->isVectorTy())
384 if (const auto *C = dyn_cast<Constant>(V))
385 if (auto *CI = dyn_cast_or_null<ConstantInt>(C->getSplatValue()))
386 if (this->isValue(CI->getValue())) {
387 Res = &CI->getValue();
388 return true;
389 }
390
391 return false;
392 }
393};
394
395/// This helper class is used to match scalar and vector constants that
396/// satisfy a specified predicate, and bind them to an APFloat.
397/// Undefs are allowed in splat vector constants.
398template <typename Predicate> struct apf_pred_ty : public Predicate {
399 const APFloat *&Res;
400
401 apf_pred_ty(const APFloat *&R) : Res(R) {}
402
403 template <typename ITy> bool match(ITy *V) {
404 if (const auto *CI = dyn_cast<ConstantFP>(V))
405 if (this->isValue(CI->getValue())) {
406 Res = &CI->getValue();
407 return true;
408 }
409 if (V->getType()->isVectorTy())
410 if (const auto *C = dyn_cast<Constant>(V))
411 if (auto *CI = dyn_cast_or_null<ConstantFP>(
412 C->getSplatValue(/* AllowUndef */ true)))
413 if (this->isValue(CI->getValue())) {
414 Res = &CI->getValue();
415 return true;
416 }
417
418 return false;
419 }
420};
421
422///////////////////////////////////////////////////////////////////////////////
423//
424// Encapsulate constant value queries for use in templated predicate matchers.
425// This allows checking if constants match using compound predicates and works
426// with vector constants, possibly with relaxed constraints. For example, ignore
427// undef values.
428//
429///////////////////////////////////////////////////////////////////////////////
430
431struct is_any_apint {
432 bool isValue(const APInt &C) { return true; }
433};
434/// Match an integer or vector with any integral constant.
435/// For vectors, this includes constants with undefined elements.
436inline cst_pred_ty<is_any_apint> m_AnyIntegralConstant() {
437 return cst_pred_ty<is_any_apint>();
438}
439
440struct is_all_ones {
441 bool isValue(const APInt &C) { return C.isAllOnesValue(); }
442};
443/// Match an integer or vector with all bits set.
444/// For vectors, this includes constants with undefined elements.
445inline cst_pred_ty<is_all_ones> m_AllOnes() {
446 return cst_pred_ty<is_all_ones>();
447}
448
449struct is_maxsignedvalue {
450 bool isValue(const APInt &C) { return C.isMaxSignedValue(); }
451};
452/// Match an integer or vector with values having all bits except for the high
453/// bit set (0x7f...).
454/// For vectors, this includes constants with undefined elements.
455inline cst_pred_ty<is_maxsignedvalue> m_MaxSignedValue() {
456 return cst_pred_ty<is_maxsignedvalue>();
457}
458inline api_pred_ty<is_maxsignedvalue> m_MaxSignedValue(const APInt *&V) {
459 return V;
460}
461
462struct is_negative {
463 bool isValue(const APInt &C) { return C.isNegative(); }
464};
465/// Match an integer or vector of negative values.
466/// For vectors, this includes constants with undefined elements.
467inline cst_pred_ty<is_negative> m_Negative() {
468 return cst_pred_ty<is_negative>();
469}
470inline api_pred_ty<is_negative> m_Negative(const APInt *&V) {
471 return V;
472}
473
474struct is_nonnegative {
475 bool isValue(const APInt &C) { return C.isNonNegative(); }
476};
477/// Match an integer or vector of non-negative values.
478/// For vectors, this includes constants with undefined elements.
479inline cst_pred_ty<is_nonnegative> m_NonNegative() {
480 return cst_pred_ty<is_nonnegative>();
481}
482inline api_pred_ty<is_nonnegative> m_NonNegative(const APInt *&V) {
483 return V;
484}
485
486struct is_strictlypositive {
487 bool isValue(const APInt &C) { return C.isStrictlyPositive(); }
488};
489/// Match an integer or vector of strictly positive values.
490/// For vectors, this includes constants with undefined elements.
491inline cst_pred_ty<is_strictlypositive> m_StrictlyPositive() {
492 return cst_pred_ty<is_strictlypositive>();
493}
494inline api_pred_ty<is_strictlypositive> m_StrictlyPositive(const APInt *&V) {
495 return V;
496}
497
498struct is_nonpositive {
499 bool isValue(const APInt &C) { return C.isNonPositive(); }
500};
501/// Match an integer or vector of non-positive values.
502/// For vectors, this includes constants with undefined elements.
503inline cst_pred_ty<is_nonpositive> m_NonPositive() {
504 return cst_pred_ty<is_nonpositive>();
505}
506inline api_pred_ty<is_nonpositive> m_NonPositive(const APInt *&V) { return V; }
507
508struct is_one {
509 bool isValue(const APInt &C) { return C.isOneValue(); }
510};
511/// Match an integer 1 or a vector with all elements equal to 1.
512/// For vectors, this includes constants with undefined elements.
513inline cst_pred_ty<is_one> m_One() {
514 return cst_pred_ty<is_one>();
515}
516
517struct is_zero_int {
518 bool isValue(const APInt &C) { return C.isNullValue(); }
519};
520/// Match an integer 0 or a vector with all elements equal to 0.
521/// For vectors, this includes constants with undefined elements.
522inline cst_pred_ty<is_zero_int> m_ZeroInt() {
523 return cst_pred_ty<is_zero_int>();
524}
525
526struct is_zero {
527 template <typename ITy> bool match(ITy *V) {
528 auto *C = dyn_cast<Constant>(V);
529 // FIXME: this should be able to do something for scalable vectors
530 return C && (C->isNullValue() || cst_pred_ty<is_zero_int>().match(C));
531 }
532};
533/// Match any null constant or a vector with all elements equal to 0.
534/// For vectors, this includes constants with undefined elements.
535inline is_zero m_Zero() {
536 return is_zero();
537}
538
539struct is_power2 {
540 bool isValue(const APInt &C) { return C.isPowerOf2(); }
541};
542/// Match an integer or vector power-of-2.
543/// For vectors, this includes constants with undefined elements.
544inline cst_pred_ty<is_power2> m_Power2() {
545 return cst_pred_ty<is_power2>();
546}
547inline api_pred_ty<is_power2> m_Power2(const APInt *&V) {
548 return V;
549}
550
551struct is_negated_power2 {
552 bool isValue(const APInt &C) { return (-C).isPowerOf2(); }
553};
554/// Match a integer or vector negated power-of-2.
555/// For vectors, this includes constants with undefined elements.
556inline cst_pred_ty<is_negated_power2> m_NegatedPower2() {
557 return cst_pred_ty<is_negated_power2>();
558}
559inline api_pred_ty<is_negated_power2> m_NegatedPower2(const APInt *&V) {
560 return V;
561}
562
563struct is_power2_or_zero {
564 bool isValue(const APInt &C) { return !C || C.isPowerOf2(); }
565};
566/// Match an integer or vector of 0 or power-of-2 values.
567/// For vectors, this includes constants with undefined elements.
568inline cst_pred_ty<is_power2_or_zero> m_Power2OrZero() {
569 return cst_pred_ty<is_power2_or_zero>();
570}
571inline api_pred_ty<is_power2_or_zero> m_Power2OrZero(const APInt *&V) {
572 return V;
573}
574
575struct is_sign_mask {
576 bool isValue(const APInt &C) { return C.isSignMask(); }
577};
578/// Match an integer or vector with only the sign bit(s) set.
579/// For vectors, this includes constants with undefined elements.
580inline cst_pred_ty<is_sign_mask> m_SignMask() {
581 return cst_pred_ty<is_sign_mask>();
582}
583
584struct is_lowbit_mask {
585 bool isValue(const APInt &C) { return C.isMask(); }
586};
587/// Match an integer or vector with only the low bit(s) set.
588/// For vectors, this includes constants with undefined elements.
589inline cst_pred_ty<is_lowbit_mask> m_LowBitMask() {
590 return cst_pred_ty<is_lowbit_mask>();
591}
592
593struct icmp_pred_with_threshold {
594 ICmpInst::Predicate Pred;
595 const APInt *Thr;
596 bool isValue(const APInt &C) {
597 switch (Pred) {
598 case ICmpInst::Predicate::ICMP_EQ:
599 return C.eq(*Thr);
600 case ICmpInst::Predicate::ICMP_NE:
601 return C.ne(*Thr);
602 case ICmpInst::Predicate::ICMP_UGT:
603 return C.ugt(*Thr);
604 case ICmpInst::Predicate::ICMP_UGE:
605 return C.uge(*Thr);
606 case ICmpInst::Predicate::ICMP_ULT:
607 return C.ult(*Thr);
608 case ICmpInst::Predicate::ICMP_ULE:
609 return C.ule(*Thr);
610 case ICmpInst::Predicate::ICMP_SGT:
611 return C.sgt(*Thr);
612 case ICmpInst::Predicate::ICMP_SGE:
613 return C.sge(*Thr);
614 case ICmpInst::Predicate::ICMP_SLT:
615 return C.slt(*Thr);
616 case ICmpInst::Predicate::ICMP_SLE:
617 return C.sle(*Thr);
618 default:
619 llvm_unreachable("Unhandled ICmp predicate")__builtin_unreachable();
620 }
621 }
622};
623/// Match an integer or vector with every element comparing 'pred' (eg/ne/...)
624/// to Threshold. For vectors, this includes constants with undefined elements.
625inline cst_pred_ty<icmp_pred_with_threshold>
626m_SpecificInt_ICMP(ICmpInst::Predicate Predicate, const APInt &Threshold) {
627 cst_pred_ty<icmp_pred_with_threshold> P;
628 P.Pred = Predicate;
629 P.Thr = &Threshold;
630 return P;
631}
632
633struct is_nan {
634 bool isValue(const APFloat &C) { return C.isNaN(); }
635};
636/// Match an arbitrary NaN constant. This includes quiet and signalling nans.
637/// For vectors, this includes constants with undefined elements.
638inline cstfp_pred_ty<is_nan> m_NaN() {
639 return cstfp_pred_ty<is_nan>();
640}
641
642struct is_nonnan {
643 bool isValue(const APFloat &C) { return !C.isNaN(); }
644};
645/// Match a non-NaN FP constant.
646/// For vectors, this includes constants with undefined elements.
647inline cstfp_pred_ty<is_nonnan> m_NonNaN() {
648 return cstfp_pred_ty<is_nonnan>();
649}
650
651struct is_inf {
652 bool isValue(const APFloat &C) { return C.isInfinity(); }
653};
654/// Match a positive or negative infinity FP constant.
655/// For vectors, this includes constants with undefined elements.
656inline cstfp_pred_ty<is_inf> m_Inf() {
657 return cstfp_pred_ty<is_inf>();
658}
659
660struct is_noninf {
661 bool isValue(const APFloat &C) { return !C.isInfinity(); }
662};
663/// Match a non-infinity FP constant, i.e. finite or NaN.
664/// For vectors, this includes constants with undefined elements.
665inline cstfp_pred_ty<is_noninf> m_NonInf() {
666 return cstfp_pred_ty<is_noninf>();
667}
668
669struct is_finite {
670 bool isValue(const APFloat &C) { return C.isFinite(); }
671};
672/// Match a finite FP constant, i.e. not infinity or NaN.
673/// For vectors, this includes constants with undefined elements.
674inline cstfp_pred_ty<is_finite> m_Finite() {
675 return cstfp_pred_ty<is_finite>();
676}
677inline apf_pred_ty<is_finite> m_Finite(const APFloat *&V) { return V; }
678
679struct is_finitenonzero {
680 bool isValue(const APFloat &C) { return C.isFiniteNonZero(); }
681};
682/// Match a finite non-zero FP constant.
683/// For vectors, this includes constants with undefined elements.
684inline cstfp_pred_ty<is_finitenonzero> m_FiniteNonZero() {
685 return cstfp_pred_ty<is_finitenonzero>();
686}
687inline apf_pred_ty<is_finitenonzero> m_FiniteNonZero(const APFloat *&V) {
688 return V;
689}
690
691struct is_any_zero_fp {
692 bool isValue(const APFloat &C) { return C.isZero(); }
693};
694/// Match a floating-point negative zero or positive zero.
695/// For vectors, this includes constants with undefined elements.
696inline cstfp_pred_ty<is_any_zero_fp> m_AnyZeroFP() {
697 return cstfp_pred_ty<is_any_zero_fp>();
698}
699
700struct is_pos_zero_fp {
701 bool isValue(const APFloat &C) { return C.isPosZero(); }
702};
703/// Match a floating-point positive zero.
704/// For vectors, this includes constants with undefined elements.
705inline cstfp_pred_ty<is_pos_zero_fp> m_PosZeroFP() {
706 return cstfp_pred_ty<is_pos_zero_fp>();
707}
708
709struct is_neg_zero_fp {
710 bool isValue(const APFloat &C) { return C.isNegZero(); }
711};
712/// Match a floating-point negative zero.
713/// For vectors, this includes constants with undefined elements.
714inline cstfp_pred_ty<is_neg_zero_fp> m_NegZeroFP() {
715 return cstfp_pred_ty<is_neg_zero_fp>();
716}
717
718struct is_non_zero_fp {
719 bool isValue(const APFloat &C) { return C.isNonZero(); }
720};
721/// Match a floating-point non-zero.
722/// For vectors, this includes constants with undefined elements.
723inline cstfp_pred_ty<is_non_zero_fp> m_NonZeroFP() {
724 return cstfp_pred_ty<is_non_zero_fp>();
725}
726
727///////////////////////////////////////////////////////////////////////////////
728
729template <typename Class> struct bind_ty {
730 Class *&VR;
731
732 bind_ty(Class *&V) : VR(V) {}
733
734 template <typename ITy> bool match(ITy *V) {
735 if (auto *CV = dyn_cast<Class>(V)) {
736 VR = CV;
737 return true;
738 }
739 return false;
740 }
741};
742
743/// Match a value, capturing it if we match.
744inline bind_ty<Value> m_Value(Value *&V) { return V; }
10
←
Calling constructor for 'bind_ty<llvm::Value>'
→
11
←
Returning from constructor for 'bind_ty<llvm::Value>'
→
12
←
Returning without writing to 'V'
→
745inline bind_ty<const Value> m_Value(const Value *&V) { return V; }
746
747/// Match an instruction, capturing it if we match.
748inline bind_ty<Instruction> m_Instruction(Instruction *&I) { return I; }
749/// Match a unary operator, capturing it if we match.
750inline bind_ty<UnaryOperator> m_UnOp(UnaryOperator *&I) { return I; }
751/// Match a binary operator, capturing it if we match.
752inline bind_ty<BinaryOperator> m_BinOp(BinaryOperator *&I) { return I; }
753/// Match a with overflow intrinsic, capturing it if we match.
754inline bind_ty<WithOverflowInst> m_WithOverflowInst(WithOverflowInst *&I) { return I; }
755inline bind_ty<const WithOverflowInst>
756m_WithOverflowInst(const WithOverflowInst *&I) {
757 return I;
758}
759
760/// Match a Constant, capturing the value if we match.
761inline bind_ty<Constant> m_Constant(Constant *&C) { return C; }
762
763/// Match a ConstantInt, capturing the value if we match.
764inline bind_ty<ConstantInt> m_ConstantInt(ConstantInt *&CI) { return CI; }
765
766/// Match a ConstantFP, capturing the value if we match.
767inline bind_ty<ConstantFP> m_ConstantFP(ConstantFP *&C) { return C; }
768
769/// Match a ConstantExpr, capturing the value if we match.
770inline bind_ty<ConstantExpr> m_ConstantExpr(ConstantExpr *&C) { return C; }
771
772/// Match a basic block value, capturing it if we match.
773inline bind_ty<BasicBlock> m_BasicBlock(BasicBlock *&V) { return V; }
774inline bind_ty<const BasicBlock> m_BasicBlock(const BasicBlock *&V) {
775 return V;
776}
777
778/// Match an arbitrary immediate Constant and ignore it.
779inline match_combine_and<class_match<Constant>,
780 match_unless<class_match<ConstantExpr>>>
781m_ImmConstant() {
782 return m_CombineAnd(m_Constant(), m_Unless(m_ConstantExpr()));
783}
784
785/// Match an immediate Constant, capturing the value if we match.
786inline match_combine_and<bind_ty<Constant>,
787 match_unless<class_match<ConstantExpr>>>
788m_ImmConstant(Constant *&C) {
789 return m_CombineAnd(m_Constant(C), m_Unless(m_ConstantExpr()));
790}
791
792/// Match a specified Value*.
793struct specificval_ty {
794 const Value *Val;
795
796 specificval_ty(const Value *V) : Val(V) {}
797
798 template <typename ITy> bool match(ITy *V) { return V == Val; }
799};
800
801/// Match if we have a specific specified value.
802inline specificval_ty m_Specific(const Value *V) { return V; }
803
804/// Stores a reference to the Value *, not the Value * itself,
805/// thus can be used in commutative matchers.
806template <typename Class> struct deferredval_ty {
807 Class *const &Val;
808
809 deferredval_ty(Class *const &V) : Val(V) {}
810
811 template <typename ITy> bool match(ITy *const V) { return V == Val; }
812};
813
814/// Like m_Specific(), but works if the specific value to match is determined
815/// as part of the same match() expression. For example:
816/// m_Add(m_Value(X), m_Specific(X)) is incorrect, because m_Specific() will
817/// bind X before the pattern match starts.
818/// m_Add(m_Value(X), m_Deferred(X)) is correct, and will check against
819/// whichever value m_Value(X) populated.
820inline deferredval_ty<Value> m_Deferred(Value *const &V) { return V; }
821inline deferredval_ty<const Value> m_Deferred(const Value *const &V) {
822 return V;
823}
824
825/// Match a specified floating point value or vector of all elements of
826/// that value.
827struct specific_fpval {
828 double Val;
829
830 specific_fpval(double V) : Val(V) {}
831
832 template <typename ITy> bool match(ITy *V) {
833 if (const auto *CFP = dyn_cast<ConstantFP>(V))
834 return CFP->isExactlyValue(Val);
835 if (V->getType()->isVectorTy())
836 if (const auto *C = dyn_cast<Constant>(V))
837 if (auto *CFP = dyn_cast_or_null<ConstantFP>(C->getSplatValue()))
838 return CFP->isExactlyValue(Val);
839 return false;
840 }
841};
842
843/// Match a specific floating point value or vector with all elements
844/// equal to the value.
845inline specific_fpval m_SpecificFP(double V) { return specific_fpval(V); }
846
847/// Match a float 1.0 or vector with all elements equal to 1.0.
848inline specific_fpval m_FPOne() { return m_SpecificFP(1.0); }
849
850struct bind_const_intval_ty {
851 uint64_t &VR;
852
853 bind_const_intval_ty(uint64_t &V) : VR(V) {}
854
855 template <typename ITy> bool match(ITy *V) {
856 if (const auto *CV = dyn_cast<ConstantInt>(V))
857 if (CV->getValue().ule(UINT64_MAX0xffffffffffffffffULL)) {
858 VR = CV->getZExtValue();
859 return true;
860 }
861 return false;
862 }
863};
864
865/// Match a specified integer value or vector of all elements of that
866/// value.
867template <bool AllowUndefs>
868struct specific_intval {
869 APInt Val;
870
871 specific_intval(APInt V) : Val(std::move(V)) {}
872
873 template <typename ITy> bool match(ITy *V) {
874 const auto *CI = dyn_cast<ConstantInt>(V);
875 if (!CI && V->getType()->isVectorTy())
876 if (const auto *C = dyn_cast<Constant>(V))
877 CI = dyn_cast_or_null<ConstantInt>(C->getSplatValue(AllowUndefs));
878
879 return CI && APInt::isSameValue(CI->getValue(), Val);
880 }
881};
882
883/// Match a specific integer value or vector with all elements equal to
884/// the value.
885inline specific_intval<false> m_SpecificInt(APInt V) {
886 return specific_intval<false>(std::move(V));
887}
888
889inline specific_intval<false> m_SpecificInt(uint64_t V) {
890 return m_SpecificInt(APInt(64, V));
891}
892
893inline specific_intval<true> m_SpecificIntAllowUndef(APInt V) {
894 return specific_intval<true>(std::move(V));
895}
896
897inline specific_intval<true> m_SpecificIntAllowUndef(uint64_t V) {
898 return m_SpecificIntAllowUndef(APInt(64, V));
899}
900
901/// Match a ConstantInt and bind to its value. This does not match
902/// ConstantInts wider than 64-bits.
903inline bind_const_intval_ty m_ConstantInt(uint64_t &V) { return V; }
904
905/// Match a specified basic block value.
906struct specific_bbval {
907 BasicBlock *Val;
908
909 specific_bbval(BasicBlock *Val) : Val(Val) {}
910
911 template <typename ITy> bool match(ITy *V) {
912 const auto *BB = dyn_cast<BasicBlock>(V);
913 return BB && BB == Val;
914 }
915};
916
917/// Match a specific basic block value.
918inline specific_bbval m_SpecificBB(BasicBlock *BB) {
919 return specific_bbval(BB);
920}
921
922/// A commutative-friendly version of m_Specific().
923inline deferredval_ty<BasicBlock> m_Deferred(BasicBlock *const &BB) {
924 return BB;
925}
926inline deferredval_ty<const BasicBlock>
927m_Deferred(const BasicBlock *const &BB) {
928 return BB;
929}
930
931//===----------------------------------------------------------------------===//
932// Matcher for any binary operator.
933//
934template <typename LHS_t, typename RHS_t, bool Commutable = false>
935struct AnyBinaryOp_match {
936 LHS_t L;
937 RHS_t R;
938
939 // The evaluation order is always stable, regardless of Commutability.
940 // The LHS is always matched first.
941 AnyBinaryOp_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
942
943 template <typename OpTy> bool match(OpTy *V) {
944 if (auto *I = dyn_cast<BinaryOperator>(V))
945 return (L.match(I->getOperand(0)) && R.match(I->getOperand(1))) ||
946 (Commutable && L.match(I->getOperand(1)) &&
947 R.match(I->getOperand(0)));
948 return false;
949 }
950};
951
952template <typename LHS, typename RHS>
953inline AnyBinaryOp_match<LHS, RHS> m_BinOp(const LHS &L, const RHS &R) {
954 return AnyBinaryOp_match<LHS, RHS>(L, R);
955}
956
957//===----------------------------------------------------------------------===//
958// Matcher for any unary operator.
959// TODO fuse unary, binary matcher into n-ary matcher
960//
961template <typename OP_t> struct AnyUnaryOp_match {
962 OP_t X;
963
964 AnyUnaryOp_match(const OP_t &X) : X(X) {}
965
966 template <typename OpTy> bool match(OpTy *V) {
967 if (auto *I = dyn_cast<UnaryOperator>(V))
968 return X.match(I->getOperand(0));
969 return false;
970 }
971};
972
973template <typename OP_t> inline AnyUnaryOp_match<OP_t> m_UnOp(const OP_t &X) {
974 return AnyUnaryOp_match<OP_t>(X);
975}
976
977//===----------------------------------------------------------------------===//
978// Matchers for specific binary operators.
979//
980
981template <typename LHS_t, typename RHS_t, unsigned Opcode,
982 bool Commutable = false>
983struct BinaryOp_match {
984 LHS_t L;
985 RHS_t R;
986
987 // The evaluation order is always stable, regardless of Commutability.
988 // The LHS is always matched first.
989 BinaryOp_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
990
991 template <typename OpTy> bool match(OpTy *V) {
992 if (V->getValueID() == Value::InstructionVal + Opcode) {
30
←
Assuming the condition is true
→
31
←
Taking true branch
→
993 auto *I = cast<BinaryOperator>(V);
32
←
'V' is a 'BinaryOperator'
→
994 return (L.match(I->getOperand(0)) && R.match(I->getOperand(1))) ||
33
←
Returning zero, which participates in a condition later
→
995 (Commutable && L.match(I->getOperand(1)) &&
996 R.match(I->getOperand(0)));
997 }
998 if (auto *CE = dyn_cast<ConstantExpr>(V))
999 return CE->getOpcode() == Opcode &&
1000 ((L.match(CE->getOperand(0)) && R.match(CE->getOperand(1))) ||
1001 (Commutable && L.match(CE->getOperand(1)) &&
1002 R.match(CE->getOperand(0))));
1003 return false;
1004 }
1005};
1006
1007template <typename LHS, typename RHS>
1008inline BinaryOp_match<LHS, RHS, Instruction::Add> m_Add(const LHS &L,
1009 const RHS &R) {
1010 return BinaryOp_match<LHS, RHS, Instruction::Add>(L, R);
1011}
1012
1013template <typename LHS, typename RHS>
1014inline BinaryOp_match<LHS, RHS, Instruction::FAdd> m_FAdd(const LHS &L,
1015 const RHS &R) {
1016 return BinaryOp_match<LHS, RHS, Instruction::FAdd>(L, R);
1017}
1018
1019template <typename LHS, typename RHS>
1020inline BinaryOp_match<LHS, RHS, Instruction::Sub> m_Sub(const LHS &L,
1021 const RHS &R) {
1022 return BinaryOp_match<LHS, RHS, Instruction::Sub>(L, R);
1023}
1024
1025template <typename LHS, typename RHS>
1026inline BinaryOp_match<LHS, RHS, Instruction::FSub> m_FSub(const LHS &L,
1027 const RHS &R) {
1028 return BinaryOp_match<LHS, RHS, Instruction::FSub>(L, R);
1029}
1030
1031template <typename Op_t> struct FNeg_match {
1032 Op_t X;
1033
1034 FNeg_match(const Op_t &Op) : X(Op) {}
1035 template <typename OpTy> bool match(OpTy *V) {
1036 auto *FPMO = dyn_cast<FPMathOperator>(V);
1037 if (!FPMO) return false;
1038
1039 if (FPMO->getOpcode() == Instruction::FNeg)
1040 return X.match(FPMO->getOperand(0));
1041
1042 if (FPMO->getOpcode() == Instruction::FSub) {
1043 if (FPMO->hasNoSignedZeros()) {
1044 // With 'nsz', any zero goes.
1045 if (!cstfp_pred_ty<is_any_zero_fp>().match(FPMO->getOperand(0)))
1046 return false;
1047 } else {
1048 // Without 'nsz', we need fsub -0.0, X exactly.
1049 if (!cstfp_pred_ty<is_neg_zero_fp>().match(FPMO->getOperand(0)))
1050 return false;
1051 }
1052
1053 return X.match(FPMO->getOperand(1));
1054 }
1055
1056 return false;
1057 }
1058};
1059
1060/// Match 'fneg X' as 'fsub -0.0, X'.
1061template <typename OpTy>
1062inline FNeg_match<OpTy>
1063m_FNeg(const OpTy &X) {
1064 return FNeg_match<OpTy>(X);
1065}
1066
1067/// Match 'fneg X' as 'fsub +-0.0, X'.
1068template <typename RHS>
1069inline BinaryOp_match<cstfp_pred_ty<is_any_zero_fp>, RHS, Instruction::FSub>
1070m_FNegNSZ(const RHS &X) {
1071 return m_FSub(m_AnyZeroFP(), X);
1072}
1073
1074template <typename LHS, typename RHS>
1075inline BinaryOp_match<LHS, RHS, Instruction::Mul> m_Mul(const LHS &L,
1076 const RHS &R) {
1077 return BinaryOp_match<LHS, RHS, Instruction::Mul>(L, R);
1078}
1079
1080template <typename LHS, typename RHS>
1081inline BinaryOp_match<LHS, RHS, Instruction::FMul> m_FMul(const LHS &L,
1082 const RHS &R) {
1083 return BinaryOp_match<LHS, RHS, Instruction::FMul>(L, R);
1084}
1085
1086template <typename LHS, typename RHS>
1087inline BinaryOp_match<LHS, RHS, Instruction::UDiv> m_UDiv(const LHS &L,
1088 const RHS &R) {
1089 return BinaryOp_match<LHS, RHS, Instruction::UDiv>(L, R);
1090}
1091
1092template <typename LHS, typename RHS>
1093inline BinaryOp_match<LHS, RHS, Instruction::SDiv> m_SDiv(const LHS &L,
1094 const RHS &R) {
1095 return BinaryOp_match<LHS, RHS, Instruction::SDiv>(L, R);
1096}
1097
1098template <typename LHS, typename RHS>
1099inline BinaryOp_match<LHS, RHS, Instruction::FDiv> m_FDiv(const LHS &L,
1100 const RHS &R) {
1101 return BinaryOp_match<LHS, RHS, Instruction::FDiv>(L, R);
1102}
1103
1104template <typename LHS, typename RHS>
1105inline BinaryOp_match<LHS, RHS, Instruction::URem> m_URem(const LHS &L,
1106 const RHS &R) {
1107 return BinaryOp_match<LHS, RHS, Instruction::URem>(L, R);
1108}
1109
1110template <typename LHS, typename RHS>
1111inline BinaryOp_match<LHS, RHS, Instruction::SRem> m_SRem(const LHS &L,
1112 const RHS &R) {
1113 return BinaryOp_match<LHS, RHS, Instruction::SRem>(L, R);
1114}
1115
1116template <typename LHS, typename RHS>
1117inline BinaryOp_match<LHS, RHS, Instruction::FRem> m_FRem(const LHS &L,
1118 const RHS &R) {
1119 return BinaryOp_match<LHS, RHS, Instruction::FRem>(L, R);
1120}
1121
1122template <typename LHS, typename RHS>
1123inline BinaryOp_match<LHS, RHS, Instruction::And> m_And(const LHS &L,
1124 const RHS &R) {
1125 return BinaryOp_match<LHS, RHS, Instruction::And>(L, R);
1126}
1127
1128template <typename LHS, typename RHS>
1129inline BinaryOp_match<LHS, RHS, Instruction::Or> m_Or(const LHS &L,
1130 const RHS &R) {
1131 return BinaryOp_match<LHS, RHS, Instruction::Or>(L, R);
1132}
1133
1134template <typename LHS, typename RHS>
1135inline BinaryOp_match<LHS, RHS, Instruction::Xor> m_Xor(const LHS &L,
1136 const RHS &R) {
1137 return BinaryOp_match<LHS, RHS, Instruction::Xor>(L, R);
1138}
1139
1140template <typename LHS, typename RHS>
1141inline BinaryOp_match<LHS, RHS, Instruction::Shl> m_Shl(const LHS &L,
1142 const RHS &R) {
1143 return BinaryOp_match<LHS, RHS, Instruction::Shl>(L, R);
1144}
1145
1146template <typename LHS, typename RHS>
1147inline BinaryOp_match<LHS, RHS, Instruction::LShr> m_LShr(const LHS &L,
1148 const RHS &R) {
1149 return BinaryOp_match<LHS, RHS, Instruction::LShr>(L, R);
1150}
1151
1152template <typename LHS, typename RHS>
1153inline BinaryOp_match<LHS, RHS, Instruction::AShr> m_AShr(const LHS &L,
1154 const RHS &R) {
1155 return BinaryOp_match<LHS, RHS, Instruction::AShr>(L, R);
1156}
1157
1158template <typename LHS_t, typename RHS_t, unsigned Opcode,
1159 unsigned WrapFlags = 0>
1160struct OverflowingBinaryOp_match {
1161 LHS_t L;
1162 RHS_t R;
1163
1164 OverflowingBinaryOp_match(const LHS_t &LHS, const RHS_t &RHS)
1165 : L(LHS), R(RHS) {}
1166
1167 template <typename OpTy> bool match(OpTy *V) {
1168 if (auto *Op = dyn_cast<OverflowingBinaryOperator>(V)) {
1169 if (Op->getOpcode() != Opcode)
1170 return false;
1171 if ((WrapFlags & OverflowingBinaryOperator::NoUnsignedWrap) &&
1172 !Op->hasNoUnsignedWrap())
1173 return false;
1174 if ((WrapFlags & OverflowingBinaryOperator::NoSignedWrap) &&
1175 !Op->hasNoSignedWrap())
1176 return false;
1177 return L.match(Op->getOperand(0)) && R.match(Op->getOperand(1));
1178 }
1179 return false;
1180 }
1181};
1182
1183template <typename LHS, typename RHS>
1184inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1185 OverflowingBinaryOperator::NoSignedWrap>
1186m_NSWAdd(const LHS &L, const RHS &R) {
1187 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1188 OverflowingBinaryOperator::NoSignedWrap>(
1189 L, R);
1190}
1191template <typename LHS, typename RHS>
1192inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1193 OverflowingBinaryOperator::NoSignedWrap>
1194m_NSWSub(const LHS &L, const RHS &R) {
1195 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1196 OverflowingBinaryOperator::NoSignedWrap>(
1197 L, R);
1198}
1199template <typename LHS, typename RHS>
1200inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1201 OverflowingBinaryOperator::NoSignedWrap>
1202m_NSWMul(const LHS &L, const RHS &R) {
1203 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1204 OverflowingBinaryOperator::NoSignedWrap>(
1205 L, R);
1206}
1207template <typename LHS, typename RHS>
1208inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1209 OverflowingBinaryOperator::NoSignedWrap>
1210m_NSWShl(const LHS &L, const RHS &R) {
1211 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1212 OverflowingBinaryOperator::NoSignedWrap>(
1213 L, R);
1214}
1215
1216template <typename LHS, typename RHS>
1217inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1218 OverflowingBinaryOperator::NoUnsignedWrap>
1219m_NUWAdd(const LHS &L, const RHS &R) {
1220 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1221 OverflowingBinaryOperator::NoUnsignedWrap>(
1222 L, R);
1223}
1224template <typename LHS, typename RHS>
1225inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1226 OverflowingBinaryOperator::NoUnsignedWrap>
1227m_NUWSub(const LHS &L, const RHS &R) {
1228 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1229 OverflowingBinaryOperator::NoUnsignedWrap>(
1230 L, R);
1231}
1232template <typename LHS, typename RHS>
1233inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1234 OverflowingBinaryOperator::NoUnsignedWrap>
1235m_NUWMul(const LHS &L, const RHS &R) {
1236 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1237 OverflowingBinaryOperator::NoUnsignedWrap>(
1238 L, R);
1239}
1240template <typename LHS, typename RHS>
1241inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1242 OverflowingBinaryOperator::NoUnsignedWrap>
1243m_NUWShl(const LHS &L, const RHS &R) {
1244 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1245 OverflowingBinaryOperator::NoUnsignedWrap>(
1246 L, R);
1247}
1248
1249//===----------------------------------------------------------------------===//
1250// Class that matches a group of binary opcodes.
1251//
1252template <typename LHS_t, typename RHS_t, typename Predicate>
1253struct BinOpPred_match : Predicate {
1254 LHS_t L;
1255 RHS_t R;
1256
1257 BinOpPred_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
1258
1259 template <typename OpTy> bool match(OpTy *V) {
1260 if (auto *I = dyn_cast<Instruction>(V))
1261 return this->isOpType(I->getOpcode()) && L.match(I->getOperand(0)) &&
1262 R.match(I->getOperand(1));
1263 if (auto *CE = dyn_cast<ConstantExpr>(V))
1264 return this->isOpType(CE->getOpcode()) && L.match(CE->getOperand(0)) &&
1265 R.match(CE->getOperand(1));
1266 return false;
1267 }
1268};
1269
1270struct is_shift_op {
1271 bool isOpType(unsigned Opcode) { return Instruction::isShift(Opcode); }
1272};
1273
1274struct is_right_shift_op {
1275 bool isOpType(unsigned Opcode) {
1276 return Opcode == Instruction::LShr || Opcode == Instruction::AShr;
1277 }
1278};
1279
1280struct is_logical_shift_op {
1281 bool isOpType(unsigned Opcode) {
1282 return Opcode == Instruction::LShr || Opcode == Instruction::Shl;
1283 }
1284};
1285
1286struct is_bitwiselogic_op {
1287 bool isOpType(unsigned Opcode) {
1288 return Instruction::isBitwiseLogicOp(Opcode);
1289 }
1290};
1291
1292struct is_idiv_op {
1293 bool isOpType(unsigned Opcode) {
1294 return Opcode == Instruction::SDiv || Opcode == Instruction::UDiv;
1295 }
1296};
1297
1298struct is_irem_op {
1299 bool isOpType(unsigned Opcode) {
1300 return Opcode == Instruction::SRem || Opcode == Instruction::URem;
1301 }
1302};
1303
1304/// Matches shift operations.
1305template <typename LHS, typename RHS>
1306inline BinOpPred_match<LHS, RHS, is_shift_op> m_Shift(const LHS &L,
1307 const RHS &R) {
1308 return BinOpPred_match<LHS, RHS, is_shift_op>(L, R);
24
←
Returning without writing to 'R.R.VR'
→
1309}
1310
1311/// Matches logical shift operations.
1312template <typename LHS, typename RHS>
1313inline BinOpPred_match<LHS, RHS, is_right_shift_op> m_Shr(const LHS &L,
1314 const RHS &R) {
1315 return BinOpPred_match<LHS, RHS, is_right_shift_op>(L, R);
1316}
1317
1318/// Matches logical shift operations.
1319template <typename LHS, typename RHS>
1320inline BinOpPred_match<LHS, RHS, is_logical_shift_op>
1321m_LogicalShift(const LHS &L, const RHS &R) {
1322 return BinOpPred_match<LHS, RHS, is_logical_shift_op>(L, R);
1323}
1324
1325/// Matches bitwise logic operations.
1326template <typename LHS, typename RHS>
1327inline BinOpPred_match<LHS, RHS, is_bitwiselogic_op>
1328m_BitwiseLogic(const LHS &L, const RHS &R) {
1329 return BinOpPred_match<LHS, RHS, is_bitwiselogic_op>(L, R);
1330}
1331
1332/// Matches integer division operations.
1333template <typename LHS, typename RHS>
1334inline BinOpPred_match<LHS, RHS, is_idiv_op> m_IDiv(const LHS &L,
1335 const RHS &R) {
1336 return BinOpPred_match<LHS, RHS, is_idiv_op>(L, R);
1337}
1338
1339/// Matches integer remainder operations.
1340template <typename LHS, typename RHS>
1341inline BinOpPred_match<LHS, RHS, is_irem_op> m_IRem(const LHS &L,
1342 const RHS &R) {
1343 return BinOpPred_match<LHS, RHS, is_irem_op>(L, R);
1344}
1345
1346//===----------------------------------------------------------------------===//
1347// Class that matches exact binary ops.
1348//
1349template <typename SubPattern_t> struct Exact_match {
1350 SubPattern_t SubPattern;
1351
1352 Exact_match(const SubPattern_t &SP) : SubPattern(SP) {}
1353
1354 template <typename OpTy> bool match(OpTy *V) {
1355 if (auto *PEO = dyn_cast<PossiblyExactOperator>(V))
1356 return PEO->isExact() && SubPattern.match(V);
1357 return false;
1358 }
1359};
1360
1361template <typename T> inline Exact_match<T> m_Exact(const T &SubPattern) {
1362 return SubPattern;
1363}
1364
1365//===----------------------------------------------------------------------===//
1366// Matchers for CmpInst classes
1367//
1368
1369template <typename LHS_t, typename RHS_t, typename Class, typename PredicateTy,
1370 bool Commutable = false>
1371struct CmpClass_match {
1372 PredicateTy &Predicate;
1373 LHS_t L;
1374 RHS_t R;
1375
1376 // The evaluation order is always stable, regardless of Commutability.
1377 // The LHS is always matched first.
1378 CmpClass_match(PredicateTy &Pred, const LHS_t &LHS, const RHS_t &RHS)
1379 : Predicate(Pred), L(LHS), R(RHS) {}
1380
1381 template <typename OpTy> bool match(OpTy *V) {
1382 if (auto *I = dyn_cast<Class>(V)) {
1383 if (L.match(I->getOperand(0)) && R.match(I->getOperand(1))) {
1384 Predicate = I->getPredicate();
1385 return true;
1386 } else if (Commutable && L.match(I->getOperand(1)) &&
1387 R.match(I->getOperand(0))) {
1388 Predicate = I->getSwappedPredicate();
1389 return true;
1390 }
1391 }
1392 return false;
1393 }
1394};
1395
1396template <typename LHS, typename RHS>
1397inline CmpClass_match<LHS, RHS, CmpInst, CmpInst::Predicate>
1398m_Cmp(CmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
1399 return CmpClass_match<LHS, RHS, CmpInst, CmpInst::Predicate>(Pred, L, R);
1400}
1401
1402template <typename LHS, typename RHS>
1403inline CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate>
1404m_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
1405 return CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate>(Pred, L, R);
1406}
1407
1408template <typename LHS, typename RHS>
1409inline CmpClass_match<LHS, RHS, FCmpInst, FCmpInst::Predicate>
1410m_FCmp(FCmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
1411 return CmpClass_match<LHS, RHS, FCmpInst, FCmpInst::Predicate>(Pred, L, R);
1412}
1413
1414//===----------------------------------------------------------------------===//
1415// Matchers for instructions with a given opcode and number of operands.
1416//
1417
1418/// Matches instructions with Opcode and three operands.
1419template <typename T0, unsigned Opcode> struct OneOps_match {
1420 T0 Op1;
1421
1422 OneOps_match(const T0 &Op1) : Op1(Op1) {}
1423
1424 template <typename OpTy> bool match(OpTy *V) {
1425 if (V->getValueID() == Value::InstructionVal + Opcode) {
1426 auto *I = cast<Instruction>(V);
1427 return Op1.match(I->getOperand(0));
1428 }
1429 return false;
1430 }
1431};
1432
1433/// Matches instructions with Opcode and three operands.
1434template <typename T0, typename T1, unsigned Opcode> struct TwoOps_match {
1435 T0 Op1;
1436 T1 Op2;
1437
1438 TwoOps_match(const T0 &Op1, const T1 &Op2) : Op1(Op1), Op2(Op2) {}
1439
1440 template <typename OpTy> bool match(OpTy *V) {
1441 if (V->getValueID() == Value::InstructionVal + Opcode) {
1442 auto *I = cast<Instruction>(V);
1443 return Op1.match(I->getOperand(0)) && Op2.match(I->getOperand(1));
1444 }
1445 return false;
1446 }
1447};
1448
1449/// Matches instructions with Opcode and three operands.
1450template <typename T0, typename T1, typename T2, unsigned Opcode>
1451struct ThreeOps_match {
1452 T0 Op1;
1453 T1 Op2;
1454 T2 Op3;
1455
1456 ThreeOps_match(const T0 &Op1, const T1 &Op2, const T2 &Op3)
1457 : Op1(Op1), Op2(Op2), Op3(Op3) {}
1458
1459 template <typename OpTy> bool match(OpTy *V) {
1460 if (V->getValueID() == Value::InstructionVal + Opcode) {
1461 auto *I = cast<Instruction>(V);
1462 return Op1.match(I->getOperand(0)) && Op2.match(I->getOperand(1)) &&
1463 Op3.match(I->getOperand(2));
1464 }
1465 return false;
1466 }
1467};
1468
1469/// Matches SelectInst.
1470template <typename Cond, typename LHS, typename RHS>
1471inline ThreeOps_match<Cond, LHS, RHS, Instruction::Select>
1472m_Select(const Cond &C, const LHS &L, const RHS &R) {
1473 return ThreeOps_match<Cond, LHS, RHS, Instruction::Select>(C, L, R);
1474}
1475
1476/// This matches a select of two constants, e.g.:
1477/// m_SelectCst<-1, 0>(m_Value(V))
1478template <int64_t L, int64_t R, typename Cond>
1479inline ThreeOps_match<Cond, constantint_match<L>, constantint_match<R>,
1480 Instruction::Select>
1481m_SelectCst(const Cond &C) {
1482 return m_Select(C, m_ConstantInt<L>(), m_ConstantInt<R>());
1483}
1484
1485/// Matches FreezeInst.
1486template <typename OpTy>
1487inline OneOps_match<OpTy, Instruction::Freeze> m_Freeze(const OpTy &Op) {
1488 return OneOps_match<OpTy, Instruction::Freeze>(Op);
1489}
1490
1491/// Matches InsertElementInst.
1492template <typename Val_t, typename Elt_t, typename Idx_t>
1493inline ThreeOps_match<Val_t, Elt_t, Idx_t, Instruction::InsertElement>
1494m_InsertElt(const Val_t &Val, const Elt_t &Elt, const Idx_t &Idx) {
1495 return ThreeOps_match<Val_t, Elt_t, Idx_t, Instruction::InsertElement>(
1496 Val, Elt, Idx);
1497}
1498
1499/// Matches ExtractElementInst.
1500template <typename Val_t, typename Idx_t>
1501inline TwoOps_match<Val_t, Idx_t, Instruction::ExtractElement>
1502m_ExtractElt(const Val_t &Val, const Idx_t &Idx) {
1503 return TwoOps_match<Val_t, Idx_t, Instruction::ExtractElement>(Val, Idx);
1504}
1505
1506/// Matches shuffle.
1507template <typename T0, typename T1, typename T2> struct Shuffle_match {
1508 T0 Op1;
1509 T1 Op2;
1510 T2 Mask;
1511
1512 Shuffle_match(const T0 &Op1, const T1 &Op2, const T2 &Mask)
1513 : Op1(Op1), Op2(Op2), Mask(Mask) {}
1514
1515 template <typename OpTy> bool match(OpTy *V) {
1516 if (auto *I = dyn_cast<ShuffleVectorInst>(V)) {
1517 return Op1.match(I->getOperand(0)) && Op2.match(I->getOperand(1)) &&
1518 Mask.match(I->getShuffleMask());
1519 }
1520 return false;
1521 }
1522};
1523
1524struct m_Mask {
1525 ArrayRef<int> &MaskRef;
1526 m_Mask(ArrayRef<int> &MaskRef) : MaskRef(MaskRef) {}
1527 bool match(ArrayRef<int> Mask) {
1528 MaskRef = Mask;
1529 return true;
1530 }
1531};
1532
1533struct m_ZeroMask {
1534 bool match(ArrayRef<int> Mask) {
1535 return all_of(Mask, [](int Elem) { return Elem == 0 || Elem == -1; });
1536 }
1537};
1538
1539struct m_SpecificMask {
1540 ArrayRef<int> &MaskRef;
1541 m_SpecificMask(ArrayRef<int> &MaskRef) : MaskRef(MaskRef) {}
1542 bool match(ArrayRef<int> Mask) { return MaskRef == Mask; }
1543};
1544
1545struct m_SplatOrUndefMask {
1546 int &SplatIndex;
1547 m_SplatOrUndefMask(int &SplatIndex) : SplatIndex(SplatIndex) {}
1548 bool match(ArrayRef<int> Mask) {
1549 auto First = find_if(Mask, [](int Elem) { return Elem != -1; });
1550 if (First == Mask.end())
1551 return false;
1552 SplatIndex = *First;
1553 return all_of(Mask,
1554 [First](int Elem) { return Elem == *First || Elem == -1; });
1555 }
1556};
1557
1558/// Matches ShuffleVectorInst independently of mask value.
1559template <typename V1_t, typename V2_t>
1560inline TwoOps_match<V1_t, V2_t, Instruction::ShuffleVector>
1561m_Shuffle(const V1_t &v1, const V2_t &v2) {
1562 return TwoOps_match<V1_t, V2_t, Instruction::ShuffleVector>(v1, v2);
1563}
1564
1565template <typename V1_t, typename V2_t, typename Mask_t>
1566inline Shuffle_match<V1_t, V2_t, Mask_t>
1567m_Shuffle(const V1_t &v1, const V2_t &v2, const Mask_t &mask) {
1568 return Shuffle_match<V1_t, V2_t, Mask_t>(v1, v2, mask);
1569}
1570
1571/// Matches LoadInst.
1572template <typename OpTy>
1573inline OneOps_match<OpTy, Instruction::Load> m_Load(const OpTy &Op) {
1574 return OneOps_match<OpTy, Instruction::Load>(Op);
1575}
1576
1577/// Matches StoreInst.
1578template <typename ValueOpTy, typename PointerOpTy>
1579inline TwoOps_match<ValueOpTy, PointerOpTy, Instruction::Store>
1580m_Store(const ValueOpTy &ValueOp, const PointerOpTy &PointerOp) {
1581 return TwoOps_match<ValueOpTy, PointerOpTy, Instruction::Store>(ValueOp,
1582 PointerOp);
1583}
1584
1585//===----------------------------------------------------------------------===//
1586// Matchers for CastInst classes
1587//
1588
1589template <typename Op_t, unsigned Opcode> struct CastClass_match {
1590 Op_t Op;
1591
1592 CastClass_match(const Op_t &OpMatch) : Op(OpMatch) {}
1593
1594 template <typename OpTy> bool match(OpTy *V) {
1595 if (auto *O = dyn_cast<Operator>(V))
1596 return O->getOpcode() == Opcode && Op.match(O->getOperand(0));
1597 return false;
1598 }
1599};
1600
1601/// Matches BitCast.
1602template <typename OpTy>
1603inline CastClass_match<OpTy, Instruction::BitCast> m_BitCast(const OpTy &Op) {
1604 return CastClass_match<OpTy, Instruction::BitCast>(Op);
1605}
1606
1607/// Matches PtrToInt.
1608template <typename OpTy>
1609inline CastClass_match<OpTy, Instruction::PtrToInt> m_PtrToInt(const OpTy &Op) {
1610 return CastClass_match<OpTy, Instruction::PtrToInt>(Op);
1611}
1612
1613/// Matches IntToPtr.
1614template <typename OpTy>
1615inline CastClass_match<OpTy, Instruction::IntToPtr> m_IntToPtr(const OpTy &Op) {
1616 return CastClass_match<OpTy, Instruction::IntToPtr>(Op);
1617}
1618
1619/// Matches Trunc.
1620template <typename OpTy>
1621inline CastClass_match<OpTy, Instruction::Trunc> m_Trunc(const OpTy &Op) {
1622 return CastClass_match<OpTy, Instruction::Trunc>(Op);
1623}
1624
1625template <typename OpTy>
1626inline match_combine_or<CastClass_match<OpTy, Instruction::Trunc>, OpTy>
1627m_TruncOrSelf(const OpTy &Op) {
1628 return m_CombineOr(m_Trunc(Op), Op);
1629}
1630
1631/// Matches SExt.
1632template <typename OpTy>
1633inline CastClass_match<OpTy, Instruction::SExt> m_SExt(const OpTy &Op) {
1634 return CastClass_match<OpTy, Instruction::SExt>(Op);
1635}
1636
1637/// Matches ZExt.
1638template <typename OpTy>
1639inline CastClass_match<OpTy, Instruction::ZExt> m_ZExt(const OpTy &Op) {
1640 return CastClass_match<OpTy, Instruction::ZExt>(Op);
16
←
Returning without writing to 'Op.VR'
→
1641}
1642
1643template <typename OpTy>
1644inline match_combine_or<CastClass_match<OpTy, Instruction::ZExt>, OpTy>
1645m_ZExtOrSelf(const OpTy &Op) {
1646 return m_CombineOr(m_ZExt(Op), Op);
15
←
Calling 'm_ZExt<llvm::PatternMatch::bind_ty<llvm::Value>>'
→
17
←
Returning from 'm_ZExt<llvm::PatternMatch::bind_ty<llvm::Value>>'
→
18
←
Calling 'm_CombineOr<llvm::PatternMatch::CastClass_match<llvm::PatternMatch::bind_ty<llvm::Value>, 39>, llvm::PatternMatch::bind_ty<llvm::Value>>'
→
20
←
Returning from 'm_CombineOr<llvm::PatternMatch::CastClass_match<llvm::PatternMatch::bind_ty<llvm::Value>, 39>, llvm::PatternMatch::bind_ty<llvm::Value>>'
→
21
←
Returning without writing to 'Op.VR'
→
1647}
1648
1649template <typename OpTy>
1650inline match_combine_or<CastClass_match<OpTy, Instruction::SExt>, OpTy>
1651m_SExtOrSelf(const OpTy &Op) {
1652 return m_CombineOr(m_SExt(Op), Op);
1653}
1654
1655template <typename OpTy>
1656inline match_combine_or<CastClass_match<OpTy, Instruction::ZExt>,
1657 CastClass_match<OpTy, Instruction::SExt>>
1658m_ZExtOrSExt(const OpTy &Op) {
1659 return m_CombineOr(m_ZExt(Op), m_SExt(Op));
1660}
1661
1662template <typename OpTy>
1663inline match_combine_or<
1664 match_combine_or<CastClass_match<OpTy, Instruction::ZExt>,
1665 CastClass_match<OpTy, Instruction::SExt>>,
1666 OpTy>
1667m_ZExtOrSExtOrSelf(const OpTy &Op) {
1668 return m_CombineOr(m_ZExtOrSExt(Op), Op);
1669}
1670
1671template <typename OpTy>
1672inline CastClass_match<OpTy, Instruction::UIToFP> m_UIToFP(const OpTy &Op) {
1673 return CastClass_match<OpTy, Instruction::UIToFP>(Op);
1674}
1675
1676template <typename OpTy>
1677inline CastClass_match<OpTy, Instruction::SIToFP> m_SIToFP(const OpTy &Op) {
1678 return CastClass_match<OpTy, Instruction::SIToFP>(Op);
1679}
1680
1681template <typename OpTy>
1682inline CastClass_match<OpTy, Instruction::FPToUI> m_FPToUI(const OpTy &Op) {
1683 return CastClass_match<OpTy, Instruction::FPToUI>(Op);
1684}
1685
1686template <typename OpTy>
1687inline CastClass_match<OpTy, Instruction::FPToSI> m_FPToSI(const OpTy &Op) {
1688 return CastClass_match<OpTy, Instruction::FPToSI>(Op);
1689}
1690
1691template <typename OpTy>
1692inline CastClass_match<OpTy, Instruction::FPTrunc> m_FPTrunc(const OpTy &Op) {
1693 return CastClass_match<OpTy, Instruction::FPTrunc>(Op);
1694}
1695
1696template <typename OpTy>
1697inline CastClass_match<OpTy, Instruction::FPExt> m_FPExt(const OpTy &Op) {
1698 return CastClass_match<OpTy, Instruction::FPExt>(Op);
1699}
1700
1701//===----------------------------------------------------------------------===//
1702// Matchers for control flow.
1703//
1704
1705struct br_match {
1706 BasicBlock *&Succ;
1707
1708 br_match(BasicBlock *&Succ) : Succ(Succ) {}
1709
1710 template <typename OpTy> bool match(OpTy *V) {
1711 if (auto *BI = dyn_cast<BranchInst>(V))
1712 if (BI->isUnconditional()) {
1713 Succ = BI->getSuccessor(0);
1714 return true;
1715 }
1716 return false;
1717 }
1718};
1719
1720inline br_match m_UnconditionalBr(BasicBlock *&Succ) { return br_match(Succ); }
1721
1722template <typename Cond_t, typename TrueBlock_t, typename FalseBlock_t>
1723struct brc_match {
1724 Cond_t Cond;
1725 TrueBlock_t T;
1726 FalseBlock_t F;
1727
1728 brc_match(const Cond_t &C, const TrueBlock_t &t, const FalseBlock_t &f)
1729 : Cond(C), T(t), F(f) {}
1730
1731 template <typename OpTy> bool match(OpTy *V) {
1732 if (auto *BI = dyn_cast<BranchInst>(V))
1733 if (BI->isConditional() && Cond.match(BI->getCondition()))
1734 return T.match(BI->getSuccessor(0)) && F.match(BI->getSuccessor(1));
1735 return false;
1736 }
1737};
1738
1739template <typename Cond_t>
1740inline brc_match<Cond_t, bind_ty<BasicBlock>, bind_ty<BasicBlock>>
1741m_Br(const Cond_t &C, BasicBlock *&T, BasicBlock *&F) {
1742 return brc_match<Cond_t, bind_ty<BasicBlock>, bind_ty<BasicBlock>>(
1743 C, m_BasicBlock(T), m_BasicBlock(F));
1744}
1745
1746template <typename Cond_t, typename TrueBlock_t, typename FalseBlock_t>
1747inline brc_match<Cond_t, TrueBlock_t, FalseBlock_t>
1748m_Br(const Cond_t &C, const TrueBlock_t &T, const FalseBlock_t &F) {
1749 return brc_match<Cond_t, TrueBlock_t, FalseBlock_t>(C, T, F);
1750}
1751
1752//===----------------------------------------------------------------------===//
1753// Matchers for max/min idioms, eg: "select (sgt x, y), x, y" -> smax(x,y).
1754//
1755
1756template <typename CmpInst_t, typename LHS_t, typename RHS_t, typename Pred_t,
1757 bool Commutable = false>
1758struct MaxMin_match {
1759 using PredType = Pred_t;
1760 LHS_t L;
1761 RHS_t R;
1762
1763 // The evaluation order is always stable, regardless of Commutability.
1764 // The LHS is always matched first.
1765 MaxMin_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
1766
1767 template <typename OpTy> bool match(OpTy *V) {
1768 if (auto *II = dyn_cast<IntrinsicInst>(V)) {
1769 Intrinsic::ID IID = II->getIntrinsicID();
1770 if ((IID == Intrinsic::smax && Pred_t::match(ICmpInst::ICMP_SGT)) ||
1771 (IID == Intrinsic::smin && Pred_t::match(ICmpInst::ICMP_SLT)) ||
1772 (IID == Intrinsic::umax && Pred_t::match(ICmpInst::ICMP_UGT)) ||
1773 (IID == Intrinsic::umin && Pred_t::match(ICmpInst::ICMP_ULT))) {
1774 Value *LHS = II->getOperand(0), *RHS = II->getOperand(1);
1775 return (L.match(LHS) && R.match(RHS)) ||
1776 (Commutable && L.match(RHS) && R.match(LHS));
1777 }
1778 }
1779 // Look for "(x pred y) ? x : y" or "(x pred y) ? y : x".
1780 auto *SI = dyn_cast<SelectInst>(V);
1781 if (!SI)
1782 return false;
1783 auto *Cmp = dyn_cast<CmpInst_t>(SI->getCondition());
1784 if (!Cmp)
1785 return false;
1786 // At this point we have a select conditioned on a comparison. Check that
1787 // it is the values returned by the select that are being compared.
1788 auto *TrueVal = SI->getTrueValue();
1789 auto *FalseVal = SI->getFalseValue();
1790 auto *LHS = Cmp->getOperand(0);
1791 auto *RHS = Cmp->getOperand(1);
1792 if ((TrueVal != LHS || FalseVal != RHS) &&
1793 (TrueVal != RHS || FalseVal != LHS))
1794 return false;
1795 typename CmpInst_t::Predicate Pred =
1796 LHS == TrueVal ? Cmp->getPredicate() : Cmp->getInversePredicate();
1797 // Does "(x pred y) ? x : y" represent the desired max/min operation?
1798 if (!Pred_t::match(Pred))
1799 return false;
1800 // It does! Bind the operands.
1801 return (L.match(LHS) && R.match(RHS)) ||
1802 (Commutable && L.match(RHS) && R.match(LHS));
1803 }
1804};
1805
1806/// Helper class for identifying signed max predicates.
1807struct smax_pred_ty {
1808 static bool match(ICmpInst::Predicate Pred) {
1809 return Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE;
1810 }
1811};
1812
1813/// Helper class for identifying signed min predicates.
1814struct smin_pred_ty {
1815 static bool match(ICmpInst::Predicate Pred) {
1816 return Pred == CmpInst::ICMP_SLT || Pred == CmpInst::ICMP_SLE;
1817 }
1818};
1819
1820/// Helper class for identifying unsigned max predicates.
1821struct umax_pred_ty {
1822 static bool match(ICmpInst::Predicate Pred) {
1823 return Pred == CmpInst::ICMP_UGT || Pred == CmpInst::ICMP_UGE;
1824 }
1825};
1826
1827/// Helper class for identifying unsigned min predicates.
1828struct umin_pred_ty {
1829 static bool match(ICmpInst::Predicate Pred) {
1830 return Pred == CmpInst::ICMP_ULT || Pred == CmpInst::ICMP_ULE;
1831 }
1832};
1833
1834/// Helper class for identifying ordered max predicates.
1835struct ofmax_pred_ty {
1836 static bool match(FCmpInst::Predicate Pred) {
1837 return Pred == CmpInst::FCMP_OGT || Pred == CmpInst::FCMP_OGE;
1838 }
1839};
1840
1841/// Helper class for identifying ordered min predicates.
1842struct ofmin_pred_ty {
1843 static bool match(FCmpInst::Predicate Pred) {
1844 return Pred == CmpInst::FCMP_OLT || Pred == CmpInst::FCMP_OLE;
1845 }
1846};
1847
1848/// Helper class for identifying unordered max predicates.
1849struct ufmax_pred_ty {
1850 static bool match(FCmpInst::Predicate Pred) {
1851 return Pred == CmpInst::FCMP_UGT || Pred == CmpInst::FCMP_UGE;
1852 }
1853};
1854
1855/// Helper class for identifying unordered min predicates.
1856struct ufmin_pred_ty {
1857 static bool match(FCmpInst::Predicate Pred) {
1858 return Pred == CmpInst::FCMP_ULT || Pred == CmpInst::FCMP_ULE;
1859 }
1860};
1861
1862template <typename LHS, typename RHS>
1863inline MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty> m_SMax(const LHS &L,
1864 const RHS &R) {
1865 return MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty>(L, R);
1866}
1867
1868template <typename LHS, typename RHS>
1869inline MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty> m_SMin(const LHS &L,
1870 const RHS &R) {
1871 return MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty>(L, R);
1872}
1873
1874template <typename LHS, typename RHS>
1875inline MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty> m_UMax(const LHS &L,
1876 const RHS &R) {
1877 return MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty>(L, R);
1878}
1879
1880template <typename LHS, typename RHS>
1881inline MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty> m_UMin(const LHS &L,
1882 const RHS &R) {
1883 return MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty>(L, R);
1884}
1885
1886template <typename LHS, typename RHS>
1887inline match_combine_or<
1888 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty>,
1889 MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty>>,
1890 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty>,
1891 MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty>>>
1892m_MaxOrMin(const LHS &L, const RHS &R) {
1893 return m_CombineOr(m_CombineOr(m_SMax(L, R), m_SMin(L, R)),
1894 m_CombineOr(m_UMax(L, R), m_UMin(L, R)));
1895}
1896
1897/// Match an 'ordered' floating point maximum function.
1898/// Floating point has one special value 'NaN'. Therefore, there is no total
1899/// order. However, if we can ignore the 'NaN' value (for example, because of a
1900/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'maximum'
1901/// semantics. In the presence of 'NaN' we have to preserve the original
1902/// select(fcmp(ogt/ge, L, R), L, R) semantics matched by this predicate.
1903///
1904/// max(L, R) iff L and R are not NaN
1905/// m_OrdFMax(L, R) = R iff L or R are NaN
1906template <typename LHS, typename RHS>
1907inline MaxMin_match<FCmpInst, LHS, RHS, ofmax_pred_ty> m_OrdFMax(const LHS &L,
1908 const RHS &R) {
1909 return MaxMin_match<FCmpInst, LHS, RHS, ofmax_pred_ty>(L, R);
1910}
1911
1912/// Match an 'ordered' floating point minimum function.
1913/// Floating point has one special value 'NaN'. Therefore, there is no total
1914/// order. However, if we can ignore the 'NaN' value (for example, because of a
1915/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'minimum'
1916/// semantics. In the presence of 'NaN' we have to preserve the original
1917/// select(fcmp(olt/le, L, R), L, R) semantics matched by this predicate.
1918///
1919/// min(L, R) iff L and R are not NaN
1920/// m_OrdFMin(L, R) = R iff L or R are NaN
1921template <typename LHS, typename RHS>
1922inline MaxMin_match<FCmpInst, LHS, RHS, ofmin_pred_ty> m_OrdFMin(const LHS &L,
1923 const RHS &R) {
1924 return MaxMin_match<FCmpInst, LHS, RHS, ofmin_pred_ty>(L, R);
1925}
1926
1927/// Match an 'unordered' floating point maximum function.
1928/// Floating point has one special value 'NaN'. Therefore, there is no total
1929/// order. However, if we can ignore the 'NaN' value (for example, because of a
1930/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'maximum'
1931/// semantics. In the presence of 'NaN' we have to preserve the original
1932/// select(fcmp(ugt/ge, L, R), L, R) semantics matched by this predicate.
1933///
1934/// max(L, R) iff L and R are not NaN
1935/// m_UnordFMax(L, R) = L iff L or R are NaN
1936template <typename LHS, typename RHS>
1937inline MaxMin_match<FCmpInst, LHS, RHS, ufmax_pred_ty>
1938m_UnordFMax(const LHS &L, const RHS &R) {
1939 return MaxMin_match<FCmpInst, LHS, RHS, ufmax_pred_ty>(L, R);
1940}
1941
1942/// Match an 'unordered' floating point minimum function.
1943/// Floating point has one special value 'NaN'. Therefore, there is no total
1944/// order. However, if we can ignore the 'NaN' value (for example, because of a
1945/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'minimum'
1946/// semantics. In the presence of 'NaN' we have to preserve the original
1947/// select(fcmp(ult/le, L, R), L, R) semantics matched by this predicate.
1948///
1949/// min(L, R) iff L and R are not NaN
1950/// m_UnordFMin(L, R) = L iff L or R are NaN
1951template <typename LHS, typename RHS>
1952inline MaxMin_match<FCmpInst, LHS, RHS, ufmin_pred_ty>
1953m_UnordFMin(const LHS &L, const RHS &R) {
1954 return MaxMin_match<FCmpInst, LHS, RHS, ufmin_pred_ty>(L, R);
1955}
1956
1957//===----------------------------------------------------------------------===//
1958// Matchers for overflow check patterns: e.g. (a + b) u< a, (a ^ -1) <u b
1959// Note that S might be matched to other instructions than AddInst.
1960//
1961
1962template <typename LHS_t, typename RHS_t, typename Sum_t>
1963struct UAddWithOverflow_match {
1964 LHS_t L;
1965 RHS_t R;
1966 Sum_t S;
1967
1968 UAddWithOverflow_match(const LHS_t &L, const RHS_t &R, const Sum_t &S)
1969 : L(L), R(R), S(S) {}
1970
1971 template <typename OpTy> bool match(OpTy *V) {
1972 Value *ICmpLHS, *ICmpRHS;
1973 ICmpInst::Predicate Pred;
1974 if (!m_ICmp(Pred, m_Value(ICmpLHS), m_Value(ICmpRHS)).match(V))
1975 return false;
1976
1977 Value *AddLHS, *AddRHS;
1978 auto AddExpr = m_Add(m_Value(AddLHS), m_Value(AddRHS));
1979
1980 // (a + b) u< a, (a + b) u< b
1981 if (Pred == ICmpInst::ICMP_ULT)
1982 if (AddExpr.match(ICmpLHS) && (ICmpRHS == AddLHS || ICmpRHS == AddRHS))
1983 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpLHS);
1984
1985 // a >u (a + b), b >u (a + b)
1986 if (Pred == ICmpInst::ICMP_UGT)
1987 if (AddExpr.match(ICmpRHS) && (ICmpLHS == AddLHS || ICmpLHS == AddRHS))
1988 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpRHS);
1989
1990 Value *Op1;
1991 auto XorExpr = m_OneUse(m_Xor(m_Value(Op1), m_AllOnes()));
1992 // (a ^ -1) <u b
1993 if (Pred == ICmpInst::ICMP_ULT) {
1994 if (XorExpr.match(ICmpLHS))
1995 return L.match(Op1) && R.match(ICmpRHS) && S.match(ICmpLHS);
1996 }
1997 // b > u (a ^ -1)
1998 if (Pred == ICmpInst::ICMP_UGT) {
1999 if (XorExpr.match(ICmpRHS))
2000 return L.match(Op1) && R.match(ICmpLHS) && S.match(ICmpRHS);
2001 }
2002
2003 // Match special-case for increment-by-1.
2004 if (Pred == ICmpInst::ICMP_EQ) {
2005 // (a + 1) == 0
2006 // (1 + a) == 0
2007 if (AddExpr.match(ICmpLHS) && m_ZeroInt().match(ICmpRHS) &&
2008 (m_One().match(AddLHS) || m_One().match(AddRHS)))
2009 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpLHS);
2010 // 0 == (a + 1)
2011 // 0 == (1 + a)
2012 if (m_ZeroInt().match(ICmpLHS) && AddExpr.match(ICmpRHS) &&
2013 (m_One().match(AddLHS) || m_One().match(AddRHS)))
2014 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpRHS);
2015 }
2016
2017 return false;
2018 }
2019};
2020
2021/// Match an icmp instruction checking for unsigned overflow on addition.
2022///
2023/// S is matched to the addition whose result is being checked for overflow, and
2024/// L and R are matched to the LHS and RHS of S.
2025template <typename LHS_t, typename RHS_t, typename Sum_t>
2026UAddWithOverflow_match<LHS_t, RHS_t, Sum_t>
2027m_UAddWithOverflow(const LHS_t &L, const RHS_t &R, const Sum_t &S) {
2028 return UAddWithOverflow_match<LHS_t, RHS_t, Sum_t>(L, R, S);
2029}
2030
2031template <typename Opnd_t> struct Argument_match {
2032 unsigned OpI;
2033 Opnd_t Val;
2034
2035 Argument_match(unsigned OpIdx, const Opnd_t &V) : OpI(OpIdx), Val(V) {}
2036
2037 template <typename OpTy> bool match(OpTy *V) {
2038 // FIXME: Should likely be switched to use `CallBase`.
2039 if (const auto *CI = dyn_cast<CallInst>(V))
2040 return Val.match(CI->getArgOperand(OpI));
2041 return false;
2042 }
2043};
2044
2045/// Match an argument.
2046template <unsigned OpI, typename Opnd_t>
2047inline Argument_match<Opnd_t> m_Argument(const Opnd_t &Op) {
2048 return Argument_match<Opnd_t>(OpI, Op);
2049}
2050
2051/// Intrinsic matchers.
2052struct IntrinsicID_match {
2053 unsigned ID;
2054
2055 IntrinsicID_match(Intrinsic::ID IntrID) : ID(IntrID) {}
2056
2057 template <typename OpTy> bool match(OpTy *V) {
2058 if (const auto *CI = dyn_cast<CallInst>(V))
2059 if (const auto *F = CI->getCalledFunction())
2060 return F->getIntrinsicID() == ID;
2061 return false;
2062 }
2063};
2064
2065/// Intrinsic matches are combinations of ID matchers, and argument
2066/// matchers. Higher arity matcher are defined recursively in terms of and-ing
2067/// them with lower arity matchers. Here's some convenient typedefs for up to
2068/// several arguments, and more can be added as needed
2069template <typename T0 = void, typename T1 = void, typename T2 = void,
2070 typename T3 = void, typename T4 = void, typename T5 = void,
2071 typename T6 = void, typename T7 = void, typename T8 = void,
2072 typename T9 = void, typename T10 = void>
2073struct m_Intrinsic_Ty;
2074template <typename T0> struct m_Intrinsic_Ty<T0> {
2075 using Ty = match_combine_and<IntrinsicID_match, Argument_match<T0>>;
2076};
2077template <typename T0, typename T1> struct m_Intrinsic_Ty<T0, T1> {
2078 using Ty =
2079 match_combine_and<typename m_Intrinsic_Ty<T0>::Ty, Argument_match<T1>>;
2080};
2081template <typename T0, typename T1, typename T2>
2082struct m_Intrinsic_Ty<T0, T1, T2> {
2083 using Ty =
2084 match_combine_and<typename m_Intrinsic_Ty<T0, T1>::Ty,
2085 Argument_match<T2>>;
2086};
2087template <typename T0, typename T1, typename T2, typename T3>
2088struct m_Intrinsic_Ty<T0, T1, T2, T3> {
2089 using Ty =
2090 match_combine_and<typename m_Intrinsic_Ty<T0, T1, T2>::Ty,
2091 Argument_match<T3>>;
2092};
2093
2094template <typename T0, typename T1, typename T2, typename T3, typename T4>
2095struct m_Intrinsic_Ty<T0, T1, T2, T3, T4> {
2096 using Ty = match_combine_and<typename m_Intrinsic_Ty<T0, T1, T2, T3>::Ty,
2097 Argument_match<T4>>;
2098};
2099
2100template <typename T0, typename T1, typename T2, typename T3, typename T4, typename T5>
2101struct m_Intrinsic_Ty<T0, T1, T2, T3, T4, T5> {
2102 using Ty = match_combine_and<typename m_Intrinsic_Ty<T0, T1, T2, T3, T4>::Ty,
2103 Argument_match<T5>>;
2104};
2105
2106/// Match intrinsic calls like this:
2107/// m_Intrinsic<Intrinsic::fabs>(m_Value(X))
2108template <Intrinsic::ID IntrID> inline IntrinsicID_match m_Intrinsic() {
2109 return IntrinsicID_match(IntrID);
2110}
2111
2112/// Matches MaskedLoad Intrinsic.
2113template <typename Opnd0, typename Opnd1, typename Opnd2, typename Opnd3>
2114inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2, Opnd3>::Ty
2115m_MaskedLoad(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2,
2116 const Opnd3 &Op3) {
2117 return m_Intrinsic<Intrinsic::masked_load>(Op0, Op1, Op2, Op3);
2118}
2119
2120template <Intrinsic::ID IntrID, typename T0>
2121inline typename m_Intrinsic_Ty<T0>::Ty m_Intrinsic(const T0 &Op0) {
2122 return m_CombineAnd(m_Intrinsic<IntrID>(), m_Argument<0>(Op0));
2123}
2124
2125template <Intrinsic::ID IntrID, typename T0, typename T1>
2126inline typename m_Intrinsic_Ty<T0, T1>::Ty m_Intrinsic(const T0 &Op0,
2127 const T1 &Op1) {
2128 return m_CombineAnd(m_Intrinsic<IntrID>(Op0), m_Argument<1>(Op1));
2129}
2130
2131template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2>
2132inline typename m_Intrinsic_Ty<T0, T1, T2>::Ty
2133m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2) {
2134 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1), m_Argument<2>(Op2));
2135}
2136
2137template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2,
2138 typename T3>
2139inline typename m_Intrinsic_Ty<T0, T1, T2, T3>::Ty
2140m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2, const T3 &Op3) {
2141 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1, Op2), m_Argument<3>(Op3));
2142}
2143
2144template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2,
2145 typename T3, typename T4>
2146inline typename m_Intrinsic_Ty<T0, T1, T2, T3, T4>::Ty
2147m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2, const T3 &Op3,
2148 const T4 &Op4) {
2149 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1, Op2, Op3),
2150 m_Argument<4>(Op4));
2151}
2152
2153template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2,
2154 typename T3, typename T4, typename T5>
2155inline typename m_Intrinsic_Ty<T0, T1, T2, T3, T4, T5>::Ty
2156m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2, const T3 &Op3,
2157 const T4 &Op4, const T5 &Op5) {
2158 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1, Op2, Op3, Op4),
2159 m_Argument<5>(Op5));
2160}
2161
2162// Helper intrinsic matching specializations.
2163template <typename Opnd0>
2164inline typename m_Intrinsic_Ty<Opnd0>::Ty m_BitReverse(const Opnd0 &Op0) {
2165 return m_Intrinsic<Intrinsic::bitreverse>(Op0);
2166}
2167
2168template <typename Opnd0>
2169inline typename m_Intrinsic_Ty<Opnd0>::Ty m_BSwap(const Opnd0 &Op0) {
2170 return m_Intrinsic<Intrinsic::bswap>(Op0);
2171}
2172
2173template <typename Opnd0>
2174inline typename m_Intrinsic_Ty<Opnd0>::Ty m_FAbs(const Opnd0 &Op0) {
2175 return m_Intrinsic<Intrinsic::fabs>(Op0);
2176}
2177
2178template <typename Opnd0>
2179inline typename m_Intrinsic_Ty<Opnd0>::Ty m_FCanonicalize(const Opnd0 &Op0) {
2180 return m_Intrinsic<Intrinsic::canonicalize>(Op0);
2181}
2182
2183template <typename Opnd0, typename Opnd1>
2184inline typename m_Intrinsic_Ty<Opnd0, Opnd1>::Ty m_FMin(const Opnd0 &Op0,
2185 const Opnd1 &Op1) {
2186 return m_Intrinsic<Intrinsic::minnum>(Op0, Op1);
2187}
2188
2189template <typename Opnd0, typename Opnd1>
2190inline typename m_Intrinsic_Ty<Opnd0, Opnd1>::Ty m_FMax(const Opnd0 &Op0,
2191 const Opnd1 &Op1) {
2192 return m_Intrinsic<Intrinsic::maxnum>(Op0, Op1);
2193}
2194
2195template <typename Opnd0, typename Opnd1, typename Opnd2>
2196inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2>::Ty
2197m_FShl(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2) {
2198 return m_Intrinsic<Intrinsic::fshl>(Op0, Op1, Op2);
2199}
2200
2201template <typename Opnd0, typename Opnd1, typename Opnd2>
2202inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2>::Ty
2203m_FShr(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2) {
2204 return m_Intrinsic<Intrinsic::fshr>(Op0, Op1, Op2);
2205}
2206
2207//===----------------------------------------------------------------------===//
2208// Matchers for two-operands operators with the operators in either order
2209//
2210
2211/// Matches a BinaryOperator with LHS and RHS in either order.
2212template <typename LHS, typename RHS>
2213inline AnyBinaryOp_match<LHS, RHS, true> m_c_BinOp(const LHS &L, const RHS &R) {
2214 return AnyBinaryOp_match<LHS, RHS, true>(L, R);
2215}
2216
2217/// Matches an ICmp with a predicate over LHS and RHS in either order.
2218/// Swaps the predicate if operands are commuted.
2219template <typename LHS, typename RHS>
2220inline CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate, true>
2221m_c_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
2222 return CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate, true>(Pred, L,
2223 R);
2224}
2225
2226/// Matches a Add with LHS and RHS in either order.
2227template <typename LHS, typename RHS>
2228inline BinaryOp_match<LHS, RHS, Instruction::Add, true> m_c_Add(const LHS &L,
2229 const RHS &R) {
2230 return BinaryOp_match<LHS, RHS, Instruction::Add, true>(L, R);
2231}
2232
2233/// Matches a Mul with LHS and RHS in either order.
2234template <typename LHS, typename RHS>
2235inline BinaryOp_match<LHS, RHS, Instruction::Mul, true> m_c_Mul(const LHS &L,
2236 const RHS &R) {
2237 return BinaryOp_match<LHS, RHS, Instruction::Mul, true>(L, R);
2238}
2239
2240/// Matches an And with LHS and RHS in either order.
2241template <typename LHS, typename RHS>
2242inline BinaryOp_match<LHS, RHS, Instruction::And, true> m_c_And(const LHS &L,
2243 const RHS &R) {
2244 return BinaryOp_match<LHS, RHS, Instruction::And, true>(L, R);
2245}
2246
2247/// Matches an Or with LHS and RHS in either order.
2248template <typename LHS, typename RHS>
2249inline BinaryOp_match<LHS, RHS, Instruction::Or, true> m_c_Or(const LHS &L,
2250 const RHS &R) {
2251 return BinaryOp_match<LHS, RHS, Instruction::Or, true>(L, R);
2252}
2253
2254/// Matches an Xor with LHS and RHS in either order.
2255template <typename LHS, typename RHS>
2256inline BinaryOp_match<LHS, RHS, Instruction::Xor, true> m_c_Xor(const LHS &L,
2257 const RHS &R) {
2258 return BinaryOp_match<LHS, RHS, Instruction::Xor, true>(L, R);
2259}
2260
2261/// Matches a 'Neg' as 'sub 0, V'.
2262template <typename ValTy>
2263inline BinaryOp_match<cst_pred_ty<is_zero_int>, ValTy, Instruction::Sub>
2264m_Neg(const ValTy &V) {
2265 return m_Sub(m_ZeroInt(), V);
2266}
2267
2268/// Matches a 'Neg' as 'sub nsw 0, V'.
2269template <typename ValTy>
2270inline OverflowingBinaryOp_match<cst_pred_ty<is_zero_int>, ValTy,
2271 Instruction::Sub,
2272 OverflowingBinaryOperator::NoSignedWrap>
2273m_NSWNeg(const ValTy &V) {
2274 return m_NSWSub(m_ZeroInt(), V);
2275}
2276
2277/// Matches a 'Not' as 'xor V, -1' or 'xor -1, V'.
2278template <typename ValTy>
2279inline BinaryOp_match<ValTy, cst_pred_ty<is_all_ones>, Instruction::Xor, true>
2280m_Not(const ValTy &V) {
2281 return m_c_Xor(V, m_AllOnes());
2282}
2283
2284/// Matches an SMin with LHS and RHS in either order.
2285template <typename LHS, typename RHS>
2286inline MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty, true>
2287m_c_SMin(const LHS &L, const RHS &R) {
2288 return MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty, true>(L, R);
2289}
2290/// Matches an SMax with LHS and RHS in either order.
2291template <typename LHS, typename RHS>
2292inline MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty, true>
2293m_c_SMax(const LHS &L, const RHS &R) {
2294 return MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty, true>(L, R);
2295}
2296/// Matches a UMin with LHS and RHS in either order.
2297template <typename LHS, typename RHS>
2298inline MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty, true>
2299m_c_UMin(const LHS &L, const RHS &R) {
2300 return MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty, true>(L, R);
2301}
2302/// Matches a UMax with LHS and RHS in either order.
2303template <typename LHS, typename RHS>
2304inline MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty, true>
2305m_c_UMax(const LHS &L, const RHS &R) {
2306 return MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty, true>(L, R);
2307}
2308
2309template <typename LHS, typename RHS>
2310inline match_combine_or<
2311 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty, true>,
2312 MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty, true>>,
2313 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty, true>,
2314 MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty, true>>>
2315m_c_MaxOrMin(const LHS &L, const RHS &R) {
2316 return m_CombineOr(m_CombineOr(m_c_SMax(L, R), m_c_SMin(L, R)),
2317 m_CombineOr(m_c_UMax(L, R), m_c_UMin(L, R)));
2318}
2319
2320/// Matches FAdd with LHS and RHS in either order.
2321template <typename LHS, typename RHS>
2322inline BinaryOp_match<LHS, RHS, Instruction::FAdd, true>
2323m_c_FAdd(const LHS &L, const RHS &R) {
2324 return BinaryOp_match<LHS, RHS, Instruction::FAdd, true>(L, R);
2325}
2326
2327/// Matches FMul with LHS and RHS in either order.
2328template <typename LHS, typename RHS>
2329inline BinaryOp_match<LHS, RHS, Instruction::FMul, true>
2330m_c_FMul(const LHS &L, const RHS &R) {
2331 return BinaryOp_match<LHS, RHS, Instruction::FMul, true>(L, R);
2332}
2333
2334template <typename Opnd_t> struct Signum_match {
2335 Opnd_t Val;
2336 Signum_match(const Opnd_t &V) : Val(V) {}
2337
2338 template <typename OpTy> bool match(OpTy *V) {
2339 unsigned TypeSize = V->getType()->getScalarSizeInBits();
2340 if (TypeSize == 0)
2341 return false;
2342
2343 unsigned ShiftWidth = TypeSize - 1;
2344 Value *OpL = nullptr, *OpR = nullptr;
2345
2346 // This is the representation of signum we match:
2347 //
2348 // signum(x) == (x >> 63) | (-x >>u 63)
2349 //
2350 // An i1 value is its own signum, so it's correct to match
2351 //
2352 // signum(x) == (x >> 0) | (-x >>u 0)
2353 //
2354 // for i1 values.
2355
2356 auto LHS = m_AShr(m_Value(OpL), m_SpecificInt(ShiftWidth));
2357 auto RHS = m_LShr(m_Neg(m_Value(OpR)), m_SpecificInt(ShiftWidth));
2358 auto Signum = m_Or(LHS, RHS);
2359
2360 return Signum.match(V) && OpL == OpR && Val.match(OpL);
2361 }
2362};
2363
2364/// Matches a signum pattern.
2365///
2366/// signum(x) =
2367/// x > 0 -> 1
2368/// x == 0 -> 0
2369/// x < 0 -> -1
2370template <typename Val_t> inline Signum_match<Val_t> m_Signum(const Val_t &V) {
2371 return Signum_match<Val_t>(V);
2372}
2373
2374template <int Ind, typename Opnd_t> struct ExtractValue_match {
2375 Opnd_t Val;
2376 ExtractValue_match(const Opnd_t &V) : Val(V) {}
2377
2378 template <typename OpTy> bool match(OpTy *V) {
2379 if (auto *I = dyn_cast<ExtractValueInst>(V)) {
2380 // If Ind is -1, don't inspect indices
2381 if (Ind != -1 &&
2382 !(I->getNumIndices() == 1 && I->getIndices()[0] == (unsigned)Ind))
2383 return false;
2384 return Val.match(I->getAggregateOperand());
2385 }
2386 return false;
2387 }
2388};
2389
2390/// Match a single index ExtractValue instruction.
2391/// For example m_ExtractValue<1>(...)
2392template <int Ind, typename Val_t>
2393inline ExtractValue_match<Ind, Val_t> m_ExtractValue(const Val_t &V) {
2394 return ExtractValue_match<Ind, Val_t>(V);
2395}
2396
2397/// Match an ExtractValue instruction with any index.
2398/// For example m_ExtractValue(...)
2399template <typename Val_t>
2400inline ExtractValue_match<-1, Val_t> m_ExtractValue(const Val_t &V) {
2401 return ExtractValue_match<-1, Val_t>(V);
2402}
2403
2404/// Matcher for a single index InsertValue instruction.
2405template <int Ind, typename T0, typename T1> struct InsertValue_match {
2406 T0 Op0;
2407 T1 Op1;
2408
2409 InsertValue_match(const T0 &Op0, const T1 &Op1) : Op0(Op0), Op1(Op1) {}
2410
2411 template <typename OpTy> bool match(OpTy *V) {
2412 if (auto *I = dyn_cast<InsertValueInst>(V)) {
2413 return Op0.match(I->getOperand(0)) && Op1.match(I->getOperand(1)) &&
2414 I->getNumIndices() == 1 && Ind == I->getIndices()[0];
2415 }
2416 return false;
2417 }
2418};
2419
2420/// Matches a single index InsertValue instruction.
2421template <int Ind, typename Val_t, typename Elt_t>
2422inline InsertValue_match<Ind, Val_t, Elt_t> m_InsertValue(const Val_t &Val,
2423 const Elt_t &Elt) {
2424 return InsertValue_match<Ind, Val_t, Elt_t>(Val, Elt);
2425}
2426
2427/// Matches patterns for `vscale`. This can either be a call to `llvm.vscale` or
2428/// the constant expression
2429/// `ptrtoint(gep <vscale x 1 x i8>, <vscale x 1 x i8>* null, i32 1>`
2430/// under the right conditions determined by DataLayout.
2431struct VScaleVal_match {
2432 const DataLayout &DL;
2433 VScaleVal_match(const DataLayout &DL) : DL(DL) {}
2434
2435 template <typename ITy> bool match(ITy *V) {
2436 if (m_Intrinsic<Intrinsic::vscale>().match(V))
2437 return true;
2438
2439 Value *Ptr;
2440 if (m_PtrToInt(m_Value(Ptr)).match(V)) {
2441 if (auto *GEP = dyn_cast<GEPOperator>(Ptr)) {
2442 auto *DerefTy = GEP->getSourceElementType();
2443 if (GEP->getNumIndices() == 1 && isa<ScalableVectorType>(DerefTy) &&
2444 m_Zero().match(GEP->getPointerOperand()) &&
2445 m_SpecificInt(1).match(GEP->idx_begin()->get()) &&
2446 DL.getTypeAllocSizeInBits(DerefTy).getKnownMinSize() == 8)
2447 return true;
2448 }
2449 }
2450
2451 return false;
2452 }
2453};
2454
2455inline VScaleVal_match m_VScale(const DataLayout &DL) {
2456 return VScaleVal_match(DL);
2457}
2458
2459template <typename LHS, typename RHS, unsigned Opcode>
2460struct LogicalOp_match {
2461 LHS L;
2462 RHS R;
2463
2464 LogicalOp_match(const LHS &L, const RHS &R) : L(L), R(R) {}
2465
2466 template <typename T> bool match(T *V) {
2467 if (auto *I = dyn_cast<Instruction>(V)) {
2468 if (!I->getType()->isIntOrIntVectorTy(1))
2469 return false;
2470
2471 if (I->getOpcode() == Opcode && L.match(I->getOperand(0)) &&
2472 R.match(I->getOperand(1)))
2473 return true;
2474
2475 if (auto *SI = dyn_cast<SelectInst>(I)) {
2476 if (Opcode == Instruction::And) {
2477 if (const auto *C = dyn_cast<Constant>(SI->getFalseValue()))
2478 if (C->isNullValue() && L.match(SI->getCondition()) &&
2479 R.match(SI->getTrueValue()))
2480 return true;
2481 } else {
2482 assert(Opcode == Instruction::Or)((void)0);
2483 if (const auto *C = dyn_cast<Constant>(SI->getTrueValue()))
2484 if (C->isOneValue() && L.match(SI->getCondition()) &&
2485 R.match(SI->getFalseValue()))
2486 return true;
2487 }
2488 }
2489 }
2490
2491 return false;
2492 }
2493};
2494
2495/// Matches L && R either in the form of L & R or L ? R : false.
2496/// Note that the latter form is poison-blocking.
2497template <typename LHS, typename RHS>
2498inline LogicalOp_match<LHS, RHS, Instruction::And>
2499m_LogicalAnd(const LHS &L, const RHS &R) {
2500 return LogicalOp_match<LHS, RHS, Instruction::And>(L, R);
2501}
2502
2503/// Matches L && R where L and R are arbitrary values.
2504inline auto m_LogicalAnd() { return m_LogicalAnd(m_Value(), m_Value()); }
2505
2506/// Matches L || R either in the form of L | R or L ? true : R.
2507/// Note that the latter form is poison-blocking.
2508template <typename LHS, typename RHS>
2509inline LogicalOp_match<LHS, RHS, Instruction::Or>
2510m_LogicalOr(const LHS &L, const RHS &R) {
2511 return LogicalOp_match<LHS, RHS, Instruction::Or>(L, R);
2512}
2513
2514/// Matches L || R where L and R are arbitrary values.
2515inline auto m_LogicalOr() {
2516 return m_LogicalOr(m_Value(), m_Value());
2517}
2518
2519} // end namespace PatternMatch
2520} // end namespace llvm
2521
2522#endif // LLVM_IR_PATTERNMATCH_H