Bug Summary

File:build/source/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
Warning:line 197, column 7
1st function call argument is an uninitialized value

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name InstCombineShifts.cpp -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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-17/lib/clang/17 -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I lib/Transforms/InstCombine -I /build/source/llvm/lib/Transforms/InstCombine -I include -I /build/source/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-17/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/source/= -source-date-epoch 1683717183 -O2 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2023-05-10-133810-16478-1 -x c++ /build/source/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp

/build/source/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/InstructionSimplify.h"
15#include "llvm/IR/IntrinsicInst.h"
16#include "llvm/IR/PatternMatch.h"
17#include "llvm/Transforms/InstCombine/InstCombiner.h"
18using namespace llvm;
19using namespace PatternMatch;
20
21#define DEBUG_TYPE"instcombine" "instcombine"
22
23bool canTryToConstantAddTwoShiftAmounts(Value *Sh0, Value *ShAmt0, Value *Sh1,
24 Value *ShAmt1) {
25 // We have two shift amounts from two different shifts. The types of those
26 // shift amounts may not match. If that's the case let's bailout now..
27 if (ShAmt0->getType() != ShAmt1->getType())
28 return false;
29
30 // As input, we have the following pattern:
31 // Sh0 (Sh1 X, Q), K
32 // We want to rewrite that as:
33 // Sh x, (Q+K) iff (Q+K) u< bitwidth(x)
34 // While we know that originally (Q+K) would not overflow
35 // (because 2 * (N-1) u<= iN -1), we have looked past extensions of
36 // shift amounts. so it may now overflow in smaller bitwidth.
37 // To ensure that does not happen, we need to ensure that the total maximal
38 // shift amount is still representable in that smaller bit width.
39 unsigned MaximalPossibleTotalShiftAmount =
40 (Sh0->getType()->getScalarSizeInBits() - 1) +
41 (Sh1->getType()->getScalarSizeInBits() - 1);
42 APInt MaximalRepresentableShiftAmount =
43 APInt::getAllOnes(ShAmt0->getType()->getScalarSizeInBits());
44 return MaximalRepresentableShiftAmount.uge(MaximalPossibleTotalShiftAmount);
45}
46
47// Given pattern:
48// (x shiftopcode Q) shiftopcode K
49// we should rewrite it as
50// x shiftopcode (Q+K) iff (Q+K) u< bitwidth(x) and
51//
52// This is valid for any shift, but they must be identical, and we must be
53// careful in case we have (zext(Q)+zext(K)) and look past extensions,
54// (Q+K) must not overflow or else (Q+K) u< bitwidth(x) is bogus.
55//
56// AnalyzeForSignBitExtraction indicates that we will only analyze whether this
57// pattern has any 2 right-shifts that sum to 1 less than original bit width.
58Value *InstCombinerImpl::reassociateShiftAmtsOfTwoSameDirectionShifts(
59 BinaryOperator *Sh0, const SimplifyQuery &SQ,
60 bool AnalyzeForSignBitExtraction) {
61 // Look for a shift of some instruction, ignore zext of shift amount if any.
62 Instruction *Sh0Op0;
63 Value *ShAmt0;
64 if (!match(Sh0,
65 m_Shift(m_Instruction(Sh0Op0), m_ZExtOrSelf(m_Value(ShAmt0)))))
66 return nullptr;
67
68 // If there is a truncation between the two shifts, we must make note of it
69 // and look through it. The truncation imposes additional constraints on the
70 // transform.
71 Instruction *Sh1;
72 Value *Trunc = nullptr;
73 match(Sh0Op0,
74 m_CombineOr(m_CombineAnd(m_Trunc(m_Instruction(Sh1)), m_Value(Trunc)),
75 m_Instruction(Sh1)));
76
77 // Inner shift: (x shiftopcode ShAmt1)
78 // Like with other shift, ignore zext of shift amount if any.
79 Value *X, *ShAmt1;
80 if (!match(Sh1, m_Shift(m_Value(X), m_ZExtOrSelf(m_Value(ShAmt1)))))
81 return nullptr;
82
83 // Verify that it would be safe to try to add those two shift amounts.
84 if (!canTryToConstantAddTwoShiftAmounts(Sh0, ShAmt0, Sh1, ShAmt1))
85 return nullptr;
86
87 // We are only looking for signbit extraction if we have two right shifts.
88 bool HadTwoRightShifts = match(Sh0, m_Shr(m_Value(), m_Value())) &&
89 match(Sh1, m_Shr(m_Value(), m_Value()));
90 // ... and if it's not two right-shifts, we know the answer already.
91 if (AnalyzeForSignBitExtraction && !HadTwoRightShifts)
92 return nullptr;
93
94 // The shift opcodes must be identical, unless we are just checking whether
95 // this pattern can be interpreted as a sign-bit-extraction.
96 Instruction::BinaryOps ShiftOpcode = Sh0->getOpcode();
97 bool IdenticalShOpcodes = Sh0->getOpcode() == Sh1->getOpcode();
98 if (!IdenticalShOpcodes && !AnalyzeForSignBitExtraction)
99 return nullptr;
100
101 // If we saw truncation, we'll need to produce extra instruction,
102 // and for that one of the operands of the shift must be one-use,
103 // unless of course we don't actually plan to produce any instructions here.
104 if (Trunc && !AnalyzeForSignBitExtraction &&
105 !match(Sh0, m_c_BinOp(m_OneUse(m_Value()), m_Value())))
106 return nullptr;
107
108 // Can we fold (ShAmt0+ShAmt1) ?
109 auto *NewShAmt = dyn_cast_or_null<Constant>(
110 simplifyAddInst(ShAmt0, ShAmt1, /*isNSW=*/false, /*isNUW=*/false,
111 SQ.getWithInstruction(Sh0)));
112 if (!NewShAmt)
113 return nullptr; // Did not simplify.
114 unsigned NewShAmtBitWidth = NewShAmt->getType()->getScalarSizeInBits();
115 unsigned XBitWidth = X->getType()->getScalarSizeInBits();
116 // Is the new shift amount smaller than the bit width of inner/new shift?
117 if (!match(NewShAmt, m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_ULT,
118 APInt(NewShAmtBitWidth, XBitWidth))))
119 return nullptr; // FIXME: could perform constant-folding.
120
121 // If there was a truncation, and we have a right-shift, we can only fold if
122 // we are left with the original sign bit. Likewise, if we were just checking
123 // that this is a sighbit extraction, this is the place to check it.
124 // FIXME: zero shift amount is also legal here, but we can't *easily* check
125 // more than one predicate so it's not really worth it.
126 if (HadTwoRightShifts && (Trunc || AnalyzeForSignBitExtraction)) {
127 // If it's not a sign bit extraction, then we're done.
128 if (!match(NewShAmt,
129 m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_EQ,
130 APInt(NewShAmtBitWidth, XBitWidth - 1))))
131 return nullptr;
132 // If it is, and that was the question, return the base value.
133 if (AnalyzeForSignBitExtraction)
134 return X;
135 }
136
137 assert(IdenticalShOpcodes && "Should not get here with different shifts.")(static_cast <bool> (IdenticalShOpcodes && "Should not get here with different shifts."
) ? void (0) : __assert_fail ("IdenticalShOpcodes && \"Should not get here with different shifts.\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 137
, __extension__ __PRETTY_FUNCTION__))
;
138
139 // All good, we can do this fold.
140 NewShAmt = ConstantExpr::getZExtOrBitCast(NewShAmt, X->getType());
141
142 BinaryOperator *NewShift = BinaryOperator::Create(ShiftOpcode, X, NewShAmt);
143
144 // The flags can only be propagated if there wasn't a trunc.
145 if (!Trunc) {
146 // If the pattern did not involve trunc, and both of the original shifts
147 // had the same flag set, preserve the flag.
148 if (ShiftOpcode == Instruction::BinaryOps::Shl) {
149 NewShift->setHasNoUnsignedWrap(Sh0->hasNoUnsignedWrap() &&
150 Sh1->hasNoUnsignedWrap());
151 NewShift->setHasNoSignedWrap(Sh0->hasNoSignedWrap() &&
152 Sh1->hasNoSignedWrap());
153 } else {
154 NewShift->setIsExact(Sh0->isExact() && Sh1->isExact());
155 }
156 }
157
158 Instruction *Ret = NewShift;
159 if (Trunc) {
160 Builder.Insert(NewShift);
161 Ret = CastInst::Create(Instruction::Trunc, NewShift, Sh0->getType());
162 }
163
164 return Ret;
165}
166
167// If we have some pattern that leaves only some low bits set, and then performs
168// left-shift of those bits, if none of the bits that are left after the final
169// shift are modified by the mask, we can omit the mask.
170//
171// There are many variants to this pattern:
172// a) (x & ((1 << MaskShAmt) - 1)) << ShiftShAmt
173// b) (x & (~(-1 << MaskShAmt))) << ShiftShAmt
174// c) (x & (-1 l>> MaskShAmt)) << ShiftShAmt
175// d) (x & ((-1 << MaskShAmt) l>> MaskShAmt)) << ShiftShAmt
176// e) ((x << MaskShAmt) l>> MaskShAmt) << ShiftShAmt
177// f) ((x << MaskShAmt) a>> MaskShAmt) << ShiftShAmt
178// All these patterns can be simplified to just:
179// x << ShiftShAmt
180// iff:
181// a,b) (MaskShAmt+ShiftShAmt) u>= bitwidth(x)
182// c,d,e,f) (ShiftShAmt-MaskShAmt) s>= 0 (i.e. ShiftShAmt u>= MaskShAmt)
183static Instruction *
184dropRedundantMaskingOfLeftShiftInput(BinaryOperator *OuterShift,
185 const SimplifyQuery &Q,
186 InstCombiner::BuilderTy &Builder) {
187 assert(OuterShift->getOpcode() == Instruction::BinaryOps::Shl &&(static_cast <bool> (OuterShift->getOpcode() == Instruction
::BinaryOps::Shl && "The input must be 'shl'!") ? void
(0) : __assert_fail ("OuterShift->getOpcode() == Instruction::BinaryOps::Shl && \"The input must be 'shl'!\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 188
, __extension__ __PRETTY_FUNCTION__))
7
Assuming the condition is true
8
'?' condition is true
188 "The input must be 'shl'!")(static_cast <bool> (OuterShift->getOpcode() == Instruction
::BinaryOps::Shl && "The input must be 'shl'!") ? void
(0) : __assert_fail ("OuterShift->getOpcode() == Instruction::BinaryOps::Shl && \"The input must be 'shl'!\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 188
, __extension__ __PRETTY_FUNCTION__))
;
189
190 Value *Masked, *ShiftShAmt;
9
'Masked' declared without an initial value
191 match(OuterShift,
18
Calling 'match<llvm::BinaryOperator, llvm::PatternMatch::BinOpPred_match<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>>, llvm::PatternMatch::is_shift_op>>'
20
Returning from 'match<llvm::BinaryOperator, llvm::PatternMatch::BinOpPred_match<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>>, llvm::PatternMatch::is_shift_op>>'
192 m_Shift(m_Value(Masked), m_ZExtOrSelf(m_Value(ShiftShAmt))));
10
Calling 'm_Value'
14
Returning from 'm_Value'
15
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>>>'
17
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>>>'
193
194 // *If* there is a truncation between an outer shift and a possibly-mask,
195 // then said truncation *must* be one-use, else we can't perform the fold.
196 Value *Trunc;
197 if (match(Masked, m_CombineAnd(m_Trunc(m_Value(Masked)), m_Value(Trunc))) &&
21
Calling 'm_Value'
25
Returning from 'm_Value'
26
Calling 'm_Trunc<llvm::PatternMatch::bind_ty<llvm::Value>>'
28
Returning from 'm_Trunc<llvm::PatternMatch::bind_ty<llvm::Value>>'
29
Calling 'm_CombineAnd<llvm::PatternMatch::CastClass_match<llvm::PatternMatch::bind_ty<llvm::Value>, 38>, llvm::PatternMatch::bind_ty<llvm::Value>>'
31
Returning from 'm_CombineAnd<llvm::PatternMatch::CastClass_match<llvm::PatternMatch::bind_ty<llvm::Value>, 38>, llvm::PatternMatch::bind_ty<llvm::Value>>'
32
1st function call argument is an uninitialized value
198 !Trunc->hasOneUse())
199 return nullptr;
200
201 Type *NarrowestTy = OuterShift->getType();
202 Type *WidestTy = Masked->getType();
203 bool HadTrunc = WidestTy != NarrowestTy;
204
205 // The mask must be computed in a type twice as wide to ensure
206 // that no bits are lost if the sum-of-shifts is wider than the base type.
207 Type *ExtendedTy = WidestTy->getExtendedType();
208
209 Value *MaskShAmt;
210
211 // ((1 << MaskShAmt) - 1)
212 auto MaskA = m_Add(m_Shl(m_One(), m_Value(MaskShAmt)), m_AllOnes());
213 // (~(-1 << maskNbits))
214 auto MaskB = m_Xor(m_Shl(m_AllOnes(), m_Value(MaskShAmt)), m_AllOnes());
215 // (-1 l>> MaskShAmt)
216 auto MaskC = m_LShr(m_AllOnes(), m_Value(MaskShAmt));
217 // ((-1 << MaskShAmt) l>> MaskShAmt)
218 auto MaskD =
219 m_LShr(m_Shl(m_AllOnes(), m_Value(MaskShAmt)), m_Deferred(MaskShAmt));
220
221 Value *X;
222 Constant *NewMask;
223
224 if (match(Masked, m_c_And(m_CombineOr(MaskA, MaskB), m_Value(X)))) {
225 // Peek through an optional zext of the shift amount.
226 match(MaskShAmt, m_ZExtOrSelf(m_Value(MaskShAmt)));
227
228 // Verify that it would be safe to try to add those two shift amounts.
229 if (!canTryToConstantAddTwoShiftAmounts(OuterShift, ShiftShAmt, Masked,
230 MaskShAmt))
231 return nullptr;
232
233 // Can we simplify (MaskShAmt+ShiftShAmt) ?
234 auto *SumOfShAmts = dyn_cast_or_null<Constant>(simplifyAddInst(
235 MaskShAmt, ShiftShAmt, /*IsNSW=*/false, /*IsNUW=*/false, Q));
236 if (!SumOfShAmts)
237 return nullptr; // Did not simplify.
238 // In this pattern SumOfShAmts correlates with the number of low bits
239 // that shall remain in the root value (OuterShift).
240
241 // An extend of an undef value becomes zero because the high bits are never
242 // completely unknown. Replace the `undef` shift amounts with final
243 // shift bitwidth to ensure that the value remains undef when creating the
244 // subsequent shift op.
245 SumOfShAmts = Constant::replaceUndefsWith(
246 SumOfShAmts, ConstantInt::get(SumOfShAmts->getType()->getScalarType(),
247 ExtendedTy->getScalarSizeInBits()));
248 auto *ExtendedSumOfShAmts = ConstantExpr::getZExt(SumOfShAmts, ExtendedTy);
249 // And compute the mask as usual: ~(-1 << (SumOfShAmts))
250 auto *ExtendedAllOnes = ConstantExpr::getAllOnesValue(ExtendedTy);
251 auto *ExtendedInvertedMask =
252 ConstantExpr::getShl(ExtendedAllOnes, ExtendedSumOfShAmts);
253 NewMask = ConstantExpr::getNot(ExtendedInvertedMask);
254 } else if (match(Masked, m_c_And(m_CombineOr(MaskC, MaskD), m_Value(X))) ||
255 match(Masked, m_Shr(m_Shl(m_Value(X), m_Value(MaskShAmt)),
256 m_Deferred(MaskShAmt)))) {
257 // Peek through an optional zext of the shift amount.
258 match(MaskShAmt, m_ZExtOrSelf(m_Value(MaskShAmt)));
259
260 // Verify that it would be safe to try to add those two shift amounts.
261 if (!canTryToConstantAddTwoShiftAmounts(OuterShift, ShiftShAmt, Masked,
262 MaskShAmt))
263 return nullptr;
264
265 // Can we simplify (ShiftShAmt-MaskShAmt) ?
266 auto *ShAmtsDiff = dyn_cast_or_null<Constant>(simplifySubInst(
267 ShiftShAmt, MaskShAmt, /*IsNSW=*/false, /*IsNUW=*/false, Q));
268 if (!ShAmtsDiff)
269 return nullptr; // Did not simplify.
270 // In this pattern ShAmtsDiff correlates with the number of high bits that
271 // shall be unset in the root value (OuterShift).
272
273 // An extend of an undef value becomes zero because the high bits are never
274 // completely unknown. Replace the `undef` shift amounts with negated
275 // bitwidth of innermost shift to ensure that the value remains undef when
276 // creating the subsequent shift op.
277 unsigned WidestTyBitWidth = WidestTy->getScalarSizeInBits();
278 ShAmtsDiff = Constant::replaceUndefsWith(
279 ShAmtsDiff, ConstantInt::get(ShAmtsDiff->getType()->getScalarType(),
280 -WidestTyBitWidth));
281 auto *ExtendedNumHighBitsToClear = ConstantExpr::getZExt(
282 ConstantExpr::getSub(ConstantInt::get(ShAmtsDiff->getType(),
283 WidestTyBitWidth,
284 /*isSigned=*/false),
285 ShAmtsDiff),
286 ExtendedTy);
287 // And compute the mask as usual: (-1 l>> (NumHighBitsToClear))
288 auto *ExtendedAllOnes = ConstantExpr::getAllOnesValue(ExtendedTy);
289 NewMask =
290 ConstantExpr::getLShr(ExtendedAllOnes, ExtendedNumHighBitsToClear);
291 } else
292 return nullptr; // Don't know anything about this pattern.
293
294 NewMask = ConstantExpr::getTrunc(NewMask, NarrowestTy);
295
296 // Does this mask has any unset bits? If not then we can just not apply it.
297 bool NeedMask = !match(NewMask, m_AllOnes());
298
299 // If we need to apply a mask, there are several more restrictions we have.
300 if (NeedMask) {
301 // The old masking instruction must go away.
302 if (!Masked->hasOneUse())
303 return nullptr;
304 // The original "masking" instruction must not have been`ashr`.
305 if (match(Masked, m_AShr(m_Value(), m_Value())))
306 return nullptr;
307 }
308
309 // If we need to apply truncation, let's do it first, since we can.
310 // We have already ensured that the old truncation will go away.
311 if (HadTrunc)
312 X = Builder.CreateTrunc(X, NarrowestTy);
313
314 // No 'NUW'/'NSW'! We no longer know that we won't shift-out non-0 bits.
315 // We didn't change the Type of this outermost shift, so we can just do it.
316 auto *NewShift = BinaryOperator::Create(OuterShift->getOpcode(), X,
317 OuterShift->getOperand(1));
318 if (!NeedMask)
319 return NewShift;
320
321 Builder.Insert(NewShift);
322 return BinaryOperator::Create(Instruction::And, NewShift, NewMask);
323}
324
325/// If we have a shift-by-constant of a bin op (bitwise logic op or add/sub w/
326/// shl) that itself has a shift-by-constant operand with identical opcode, we
327/// may be able to convert that into 2 independent shifts followed by the logic
328/// op. This eliminates a use of an intermediate value (reduces dependency
329/// chain).
330static Instruction *foldShiftOfShiftedBinOp(BinaryOperator &I,
331 InstCombiner::BuilderTy &Builder) {
332 assert(I.isShift() && "Expected a shift as input")(static_cast <bool> (I.isShift() && "Expected a shift as input"
) ? void (0) : __assert_fail ("I.isShift() && \"Expected a shift as input\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 332
, __extension__ __PRETTY_FUNCTION__))
;
333 auto *BinInst = dyn_cast<BinaryOperator>(I.getOperand(0));
334 if (!BinInst ||
335 (!BinInst->isBitwiseLogicOp() &&
336 BinInst->getOpcode() != Instruction::Add &&
337 BinInst->getOpcode() != Instruction::Sub) ||
338 !BinInst->hasOneUse())
339 return nullptr;
340
341 Constant *C0, *C1;
342 if (!match(I.getOperand(1), m_Constant(C1)))
343 return nullptr;
344
345 Instruction::BinaryOps ShiftOpcode = I.getOpcode();
346 // Transform for add/sub only works with shl.
347 if ((BinInst->getOpcode() == Instruction::Add ||
348 BinInst->getOpcode() == Instruction::Sub) &&
349 ShiftOpcode != Instruction::Shl)
350 return nullptr;
351
352 Type *Ty = I.getType();
353
354 // Find a matching one-use shift by constant. The fold is not valid if the sum
355 // of the shift values equals or exceeds bitwidth.
356 // TODO: Remove the one-use check if the other logic operand (Y) is constant.
357 Value *X, *Y;
358 auto matchFirstShift = [&](Value *V) {
359 APInt Threshold(Ty->getScalarSizeInBits(), Ty->getScalarSizeInBits());
360 return match(V,
361 m_OneUse(m_BinOp(ShiftOpcode, m_Value(X), m_Constant(C0)))) &&
362 match(ConstantExpr::getAdd(C0, C1),
363 m_SpecificInt_ICMP(ICmpInst::ICMP_ULT, Threshold));
364 };
365
366 // Logic ops and Add are commutative, so check each operand for a match. Sub
367 // is not so we cannot reoder if we match operand(1) and need to keep the
368 // operands in their original positions.
369 bool FirstShiftIsOp1 = false;
370 if (matchFirstShift(BinInst->getOperand(0)))
371 Y = BinInst->getOperand(1);
372 else if (matchFirstShift(BinInst->getOperand(1))) {
373 Y = BinInst->getOperand(0);
374 FirstShiftIsOp1 = BinInst->getOpcode() == Instruction::Sub;
375 } else
376 return nullptr;
377
378 // shift (binop (shift X, C0), Y), C1 -> binop (shift X, C0+C1), (shift Y, C1)
379 Constant *ShiftSumC = ConstantExpr::getAdd(C0, C1);
380 Value *NewShift1 = Builder.CreateBinOp(ShiftOpcode, X, ShiftSumC);
381 Value *NewShift2 = Builder.CreateBinOp(ShiftOpcode, Y, C1);
382 Value *Op1 = FirstShiftIsOp1 ? NewShift2 : NewShift1;
383 Value *Op2 = FirstShiftIsOp1 ? NewShift1 : NewShift2;
384 return BinaryOperator::Create(BinInst->getOpcode(), Op1, Op2);
385}
386
387Instruction *InstCombinerImpl::commonShiftTransforms(BinaryOperator &I) {
388 if (Instruction *Phi = foldBinopWithPhiOperands(I))
389 return Phi;
390
391 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
392 assert(Op0->getType() == Op1->getType())(static_cast <bool> (Op0->getType() == Op1->getType
()) ? void (0) : __assert_fail ("Op0->getType() == Op1->getType()"
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 392
, __extension__ __PRETTY_FUNCTION__))
;
393 Type *Ty = I.getType();
394
395 // If the shift amount is a one-use `sext`, we can demote it to `zext`.
396 Value *Y;
397 if (match(Op1, m_OneUse(m_SExt(m_Value(Y))))) {
398 Value *NewExt = Builder.CreateZExt(Y, Ty, Op1->getName());
399 return BinaryOperator::Create(I.getOpcode(), Op0, NewExt);
400 }
401
402 // See if we can fold away this shift.
403 if (SimplifyDemandedInstructionBits(I))
404 return &I;
405
406 // Try to fold constant and into select arguments.
407 if (isa<Constant>(Op0))
408 if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
409 if (Instruction *R = FoldOpIntoSelect(I, SI))
410 return R;
411
412 if (Constant *CUI = dyn_cast<Constant>(Op1))
413 if (Instruction *Res = FoldShiftByConstant(Op0, CUI, I))
414 return Res;
415
416 if (auto *NewShift = cast_or_null<Instruction>(
417 reassociateShiftAmtsOfTwoSameDirectionShifts(&I, SQ)))
418 return NewShift;
419
420 // Pre-shift a constant shifted by a variable amount with constant offset:
421 // C shift (A add nuw C1) --> (C shift C1) shift A
422 Value *A;
423 Constant *C, *C1;
424 if (match(Op0, m_Constant(C)) &&
425 match(Op1, m_NUWAdd(m_Value(A), m_Constant(C1)))) {
426 Value *NewC = Builder.CreateBinOp(I.getOpcode(), C, C1);
427 return BinaryOperator::Create(I.getOpcode(), NewC, A);
428 }
429
430 unsigned BitWidth = Ty->getScalarSizeInBits();
431
432 const APInt *AC, *AddC;
433 // Try to pre-shift a constant shifted by a variable amount added with a
434 // negative number:
435 // C << (X - AddC) --> (C >> AddC) << X
436 // and
437 // C >> (X - AddC) --> (C << AddC) >> X
438 if (match(Op0, m_APInt(AC)) && match(Op1, m_Add(m_Value(A), m_APInt(AddC))) &&
439 AddC->isNegative() && (-*AddC).ult(BitWidth)) {
440 assert(!AC->isZero() && "Expected simplify of shifted zero")(static_cast <bool> (!AC->isZero() && "Expected simplify of shifted zero"
) ? void (0) : __assert_fail ("!AC->isZero() && \"Expected simplify of shifted zero\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 440
, __extension__ __PRETTY_FUNCTION__))
;
441 unsigned PosOffset = (-*AddC).getZExtValue();
442
443 auto isSuitableForPreShift = [PosOffset, &I, AC]() {
444 switch (I.getOpcode()) {
445 default:
446 return false;
447 case Instruction::Shl:
448 return (I.hasNoSignedWrap() || I.hasNoUnsignedWrap()) &&
449 AC->eq(AC->lshr(PosOffset).shl(PosOffset));
450 case Instruction::LShr:
451 return I.isExact() && AC->eq(AC->shl(PosOffset).lshr(PosOffset));
452 case Instruction::AShr:
453 return I.isExact() && AC->eq(AC->shl(PosOffset).ashr(PosOffset));
454 }
455 };
456 if (isSuitableForPreShift()) {
457 Constant *NewC = ConstantInt::get(Ty, I.getOpcode() == Instruction::Shl
458 ? AC->lshr(PosOffset)
459 : AC->shl(PosOffset));
460 BinaryOperator *NewShiftOp =
461 BinaryOperator::Create(I.getOpcode(), NewC, A);
462 if (I.getOpcode() == Instruction::Shl) {
463 NewShiftOp->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
464 } else {
465 NewShiftOp->setIsExact();
466 }
467 return NewShiftOp;
468 }
469 }
470
471 // X shift (A srem C) -> X shift (A and (C - 1)) iff C is a power of 2.
472 // Because shifts by negative values (which could occur if A were negative)
473 // are undefined.
474 if (Op1->hasOneUse() && match(Op1, m_SRem(m_Value(A), m_Constant(C))) &&
475 match(C, m_Power2())) {
476 // FIXME: Should this get moved into SimplifyDemandedBits by saying we don't
477 // demand the sign bit (and many others) here??
478 Constant *Mask = ConstantExpr::getSub(C, ConstantInt::get(Ty, 1));
479 Value *Rem = Builder.CreateAnd(A, Mask, Op1->getName());
480 return replaceOperand(I, 1, Rem);
481 }
482
483 if (Instruction *Logic = foldShiftOfShiftedBinOp(I, Builder))
484 return Logic;
485
486 if (match(Op1, m_Or(m_Value(), m_SpecificInt(BitWidth - 1))))
487 return replaceOperand(I, 1, ConstantInt::get(Ty, BitWidth - 1));
488
489 return nullptr;
490}
491
492/// Return true if we can simplify two logical (either left or right) shifts
493/// that have constant shift amounts: OuterShift (InnerShift X, C1), C2.
494static bool canEvaluateShiftedShift(unsigned OuterShAmt, bool IsOuterShl,
495 Instruction *InnerShift,
496 InstCombinerImpl &IC, Instruction *CxtI) {
497 assert(InnerShift->isLogicalShift() && "Unexpected instruction type")(static_cast <bool> (InnerShift->isLogicalShift() &&
"Unexpected instruction type") ? void (0) : __assert_fail ("InnerShift->isLogicalShift() && \"Unexpected instruction type\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 497
, __extension__ __PRETTY_FUNCTION__))
;
498
499 // We need constant scalar or constant splat shifts.
500 const APInt *InnerShiftConst;
501 if (!match(InnerShift->getOperand(1), m_APInt(InnerShiftConst)))
502 return false;
503
504 // Two logical shifts in the same direction:
505 // shl (shl X, C1), C2 --> shl X, C1 + C2
506 // lshr (lshr X, C1), C2 --> lshr X, C1 + C2
507 bool IsInnerShl = InnerShift->getOpcode() == Instruction::Shl;
508 if (IsInnerShl == IsOuterShl)
509 return true;
510
511 // Equal shift amounts in opposite directions become bitwise 'and':
512 // lshr (shl X, C), C --> and X, C'
513 // shl (lshr X, C), C --> and X, C'
514 if (*InnerShiftConst == OuterShAmt)
515 return true;
516
517 // If the 2nd shift is bigger than the 1st, we can fold:
518 // lshr (shl X, C1), C2 --> and (shl X, C1 - C2), C3
519 // shl (lshr X, C1), C2 --> and (lshr X, C1 - C2), C3
520 // but it isn't profitable unless we know the and'd out bits are already zero.
521 // Also, check that the inner shift is valid (less than the type width) or
522 // we'll crash trying to produce the bit mask for the 'and'.
523 unsigned TypeWidth = InnerShift->getType()->getScalarSizeInBits();
524 if (InnerShiftConst->ugt(OuterShAmt) && InnerShiftConst->ult(TypeWidth)) {
525 unsigned InnerShAmt = InnerShiftConst->getZExtValue();
526 unsigned MaskShift =
527 IsInnerShl ? TypeWidth - InnerShAmt : InnerShAmt - OuterShAmt;
528 APInt Mask = APInt::getLowBitsSet(TypeWidth, OuterShAmt) << MaskShift;
529 if (IC.MaskedValueIsZero(InnerShift->getOperand(0), Mask, 0, CxtI))
530 return true;
531 }
532
533 return false;
534}
535
536/// See if we can compute the specified value, but shifted logically to the left
537/// or right by some number of bits. This should return true if the expression
538/// can be computed for the same cost as the current expression tree. This is
539/// used to eliminate extraneous shifting from things like:
540/// %C = shl i128 %A, 64
541/// %D = shl i128 %B, 96
542/// %E = or i128 %C, %D
543/// %F = lshr i128 %E, 64
544/// where the client will ask if E can be computed shifted right by 64-bits. If
545/// this succeeds, getShiftedValue() will be called to produce the value.
546static bool canEvaluateShifted(Value *V, unsigned NumBits, bool IsLeftShift,
547 InstCombinerImpl &IC, Instruction *CxtI) {
548 // We can always evaluate constants shifted.
549 if (isa<Constant>(V))
550 return true;
551
552 Instruction *I = dyn_cast<Instruction>(V);
553 if (!I) return false;
554
555 // We can't mutate something that has multiple uses: doing so would
556 // require duplicating the instruction in general, which isn't profitable.
557 if (!I->hasOneUse()) return false;
558
559 switch (I->getOpcode()) {
560 default: return false;
561 case Instruction::And:
562 case Instruction::Or:
563 case Instruction::Xor:
564 // Bitwise operators can all arbitrarily be arbitrarily evaluated shifted.
565 return canEvaluateShifted(I->getOperand(0), NumBits, IsLeftShift, IC, I) &&
566 canEvaluateShifted(I->getOperand(1), NumBits, IsLeftShift, IC, I);
567
568 case Instruction::Shl:
569 case Instruction::LShr:
570 return canEvaluateShiftedShift(NumBits, IsLeftShift, I, IC, CxtI);
571
572 case Instruction::Select: {
573 SelectInst *SI = cast<SelectInst>(I);
574 Value *TrueVal = SI->getTrueValue();
575 Value *FalseVal = SI->getFalseValue();
576 return canEvaluateShifted(TrueVal, NumBits, IsLeftShift, IC, SI) &&
577 canEvaluateShifted(FalseVal, NumBits, IsLeftShift, IC, SI);
578 }
579 case Instruction::PHI: {
580 // We can change a phi if we can change all operands. Note that we never
581 // get into trouble with cyclic PHIs here because we only consider
582 // instructions with a single use.
583 PHINode *PN = cast<PHINode>(I);
584 for (Value *IncValue : PN->incoming_values())
585 if (!canEvaluateShifted(IncValue, NumBits, IsLeftShift, IC, PN))
586 return false;
587 return true;
588 }
589 case Instruction::Mul: {
590 const APInt *MulConst;
591 // We can fold (shr (mul X, -(1 << C)), C) -> (and (neg X), C`)
592 return !IsLeftShift && match(I->getOperand(1), m_APInt(MulConst)) &&
593 MulConst->isNegatedPowerOf2() && MulConst->countr_zero() == NumBits;
594 }
595 }
596}
597
598/// Fold OuterShift (InnerShift X, C1), C2.
599/// See canEvaluateShiftedShift() for the constraints on these instructions.
600static Value *foldShiftedShift(BinaryOperator *InnerShift, unsigned OuterShAmt,
601 bool IsOuterShl,
602 InstCombiner::BuilderTy &Builder) {
603 bool IsInnerShl = InnerShift->getOpcode() == Instruction::Shl;
604 Type *ShType = InnerShift->getType();
605 unsigned TypeWidth = ShType->getScalarSizeInBits();
606
607 // We only accept shifts-by-a-constant in canEvaluateShifted().
608 const APInt *C1;
609 match(InnerShift->getOperand(1), m_APInt(C1));
610 unsigned InnerShAmt = C1->getZExtValue();
611
612 // Change the shift amount and clear the appropriate IR flags.
613 auto NewInnerShift = [&](unsigned ShAmt) {
614 InnerShift->setOperand(1, ConstantInt::get(ShType, ShAmt));
615 if (IsInnerShl) {
616 InnerShift->setHasNoUnsignedWrap(false);
617 InnerShift->setHasNoSignedWrap(false);
618 } else {
619 InnerShift->setIsExact(false);
620 }
621 return InnerShift;
622 };
623
624 // Two logical shifts in the same direction:
625 // shl (shl X, C1), C2 --> shl X, C1 + C2
626 // lshr (lshr X, C1), C2 --> lshr X, C1 + C2
627 if (IsInnerShl == IsOuterShl) {
628 // If this is an oversized composite shift, then unsigned shifts get 0.
629 if (InnerShAmt + OuterShAmt >= TypeWidth)
630 return Constant::getNullValue(ShType);
631
632 return NewInnerShift(InnerShAmt + OuterShAmt);
633 }
634
635 // Equal shift amounts in opposite directions become bitwise 'and':
636 // lshr (shl X, C), C --> and X, C'
637 // shl (lshr X, C), C --> and X, C'
638 if (InnerShAmt == OuterShAmt) {
639 APInt Mask = IsInnerShl
640 ? APInt::getLowBitsSet(TypeWidth, TypeWidth - OuterShAmt)
641 : APInt::getHighBitsSet(TypeWidth, TypeWidth - OuterShAmt);
642 Value *And = Builder.CreateAnd(InnerShift->getOperand(0),
643 ConstantInt::get(ShType, Mask));
644 if (auto *AndI = dyn_cast<Instruction>(And)) {
645 AndI->moveBefore(InnerShift);
646 AndI->takeName(InnerShift);
647 }
648 return And;
649 }
650
651 assert(InnerShAmt > OuterShAmt &&(static_cast <bool> (InnerShAmt > OuterShAmt &&
"Unexpected opposite direction logical shift pair") ? void (
0) : __assert_fail ("InnerShAmt > OuterShAmt && \"Unexpected opposite direction logical shift pair\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 652
, __extension__ __PRETTY_FUNCTION__))
652 "Unexpected opposite direction logical shift pair")(static_cast <bool> (InnerShAmt > OuterShAmt &&
"Unexpected opposite direction logical shift pair") ? void (
0) : __assert_fail ("InnerShAmt > OuterShAmt && \"Unexpected opposite direction logical shift pair\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 652
, __extension__ __PRETTY_FUNCTION__))
;
653
654 // In general, we would need an 'and' for this transform, but
655 // canEvaluateShiftedShift() guarantees that the masked-off bits are not used.
656 // lshr (shl X, C1), C2 --> shl X, C1 - C2
657 // shl (lshr X, C1), C2 --> lshr X, C1 - C2
658 return NewInnerShift(InnerShAmt - OuterShAmt);
659}
660
661/// When canEvaluateShifted() returns true for an expression, this function
662/// inserts the new computation that produces the shifted value.
663static Value *getShiftedValue(Value *V, unsigned NumBits, bool isLeftShift,
664 InstCombinerImpl &IC, const DataLayout &DL) {
665 // We can always evaluate constants shifted.
666 if (Constant *C = dyn_cast<Constant>(V)) {
667 if (isLeftShift)
668 return IC.Builder.CreateShl(C, NumBits);
669 else
670 return IC.Builder.CreateLShr(C, NumBits);
671 }
672
673 Instruction *I = cast<Instruction>(V);
674 IC.addToWorklist(I);
675
676 switch (I->getOpcode()) {
677 default: llvm_unreachable("Inconsistency with CanEvaluateShifted")::llvm::llvm_unreachable_internal("Inconsistency with CanEvaluateShifted"
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 677
)
;
678 case Instruction::And:
679 case Instruction::Or:
680 case Instruction::Xor:
681 // Bitwise operators can all arbitrarily be arbitrarily evaluated shifted.
682 I->setOperand(
683 0, getShiftedValue(I->getOperand(0), NumBits, isLeftShift, IC, DL));
684 I->setOperand(
685 1, getShiftedValue(I->getOperand(1), NumBits, isLeftShift, IC, DL));
686 return I;
687
688 case Instruction::Shl:
689 case Instruction::LShr:
690 return foldShiftedShift(cast<BinaryOperator>(I), NumBits, isLeftShift,
691 IC.Builder);
692
693 case Instruction::Select:
694 I->setOperand(
695 1, getShiftedValue(I->getOperand(1), NumBits, isLeftShift, IC, DL));
696 I->setOperand(
697 2, getShiftedValue(I->getOperand(2), NumBits, isLeftShift, IC, DL));
698 return I;
699 case Instruction::PHI: {
700 // We can change a phi if we can change all operands. Note that we never
701 // get into trouble with cyclic PHIs here because we only consider
702 // instructions with a single use.
703 PHINode *PN = cast<PHINode>(I);
704 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
705 PN->setIncomingValue(i, getShiftedValue(PN->getIncomingValue(i), NumBits,
706 isLeftShift, IC, DL));
707 return PN;
708 }
709 case Instruction::Mul: {
710 assert(!isLeftShift && "Unexpected shift direction!")(static_cast <bool> (!isLeftShift && "Unexpected shift direction!"
) ? void (0) : __assert_fail ("!isLeftShift && \"Unexpected shift direction!\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 710
, __extension__ __PRETTY_FUNCTION__))
;
711 auto *Neg = BinaryOperator::CreateNeg(I->getOperand(0));
712 IC.InsertNewInstWith(Neg, *I);
713 unsigned TypeWidth = I->getType()->getScalarSizeInBits();
714 APInt Mask = APInt::getLowBitsSet(TypeWidth, TypeWidth - NumBits);
715 auto *And = BinaryOperator::CreateAnd(Neg,
716 ConstantInt::get(I->getType(), Mask));
717 And->takeName(I);
718 return IC.InsertNewInstWith(And, *I);
719 }
720 }
721}
722
723// If this is a bitwise operator or add with a constant RHS we might be able
724// to pull it through a shift.
725static bool canShiftBinOpWithConstantRHS(BinaryOperator &Shift,
726 BinaryOperator *BO) {
727 switch (BO->getOpcode()) {
728 default:
729 return false; // Do not perform transform!
730 case Instruction::Add:
731 return Shift.getOpcode() == Instruction::Shl;
732 case Instruction::Or:
733 case Instruction::And:
734 return true;
735 case Instruction::Xor:
736 // Do not change a 'not' of logical shift because that would create a normal
737 // 'xor'. The 'not' is likely better for analysis, SCEV, and codegen.
738 return !(Shift.isLogicalShift() && match(BO, m_Not(m_Value())));
739 }
740}
741
742Instruction *InstCombinerImpl::FoldShiftByConstant(Value *Op0, Constant *C1,
743 BinaryOperator &I) {
744 // (C2 << X) << C1 --> (C2 << C1) << X
745 // (C2 >> X) >> C1 --> (C2 >> C1) >> X
746 Constant *C2;
747 Value *X;
748 if (match(Op0, m_BinOp(I.getOpcode(), m_Constant(C2), m_Value(X))))
749 return BinaryOperator::Create(
750 I.getOpcode(), Builder.CreateBinOp(I.getOpcode(), C2, C1), X);
751
752 bool IsLeftShift = I.getOpcode() == Instruction::Shl;
753 Type *Ty = I.getType();
754 unsigned TypeBits = Ty->getScalarSizeInBits();
755
756 // (X / +DivC) >> (Width - 1) --> ext (X <= -DivC)
757 // (X / -DivC) >> (Width - 1) --> ext (X >= +DivC)
758 const APInt *DivC;
759 if (!IsLeftShift && match(C1, m_SpecificIntAllowUndef(TypeBits - 1)) &&
760 match(Op0, m_SDiv(m_Value(X), m_APInt(DivC))) && !DivC->isZero() &&
761 !DivC->isMinSignedValue()) {
762 Constant *NegDivC = ConstantInt::get(Ty, -(*DivC));
763 ICmpInst::Predicate Pred =
764 DivC->isNegative() ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_SLE;
765 Value *Cmp = Builder.CreateICmp(Pred, X, NegDivC);
766 auto ExtOpcode = (I.getOpcode() == Instruction::AShr) ? Instruction::SExt
767 : Instruction::ZExt;
768 return CastInst::Create(ExtOpcode, Cmp, Ty);
769 }
770
771 const APInt *Op1C;
772 if (!match(C1, m_APInt(Op1C)))
773 return nullptr;
774
775 assert(!Op1C->uge(TypeBits) &&(static_cast <bool> (!Op1C->uge(TypeBits) &&
"Shift over the type width should have been removed already"
) ? void (0) : __assert_fail ("!Op1C->uge(TypeBits) && \"Shift over the type width should have been removed already\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 776
, __extension__ __PRETTY_FUNCTION__))
776 "Shift over the type width should have been removed already")(static_cast <bool> (!Op1C->uge(TypeBits) &&
"Shift over the type width should have been removed already"
) ? void (0) : __assert_fail ("!Op1C->uge(TypeBits) && \"Shift over the type width should have been removed already\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 776
, __extension__ __PRETTY_FUNCTION__))
;
777
778 // See if we can propagate this shift into the input, this covers the trivial
779 // cast of lshr(shl(x,c1),c2) as well as other more complex cases.
780 if (I.getOpcode() != Instruction::AShr &&
781 canEvaluateShifted(Op0, Op1C->getZExtValue(), IsLeftShift, *this, &I)) {
782 LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("instcombine")) { dbgs() << "ICE: GetShiftedValue propagating shift through expression"
" to eliminate shift:\n IN: " << *Op0 << "\n SH: "
<< I << "\n"; } } while (false)
783 dbgs() << "ICE: GetShiftedValue propagating shift through expression"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("instcombine")) { dbgs() << "ICE: GetShiftedValue propagating shift through expression"
" to eliminate shift:\n IN: " << *Op0 << "\n SH: "
<< I << "\n"; } } while (false)
784 " to eliminate shift:\n IN: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("instcombine")) { dbgs() << "ICE: GetShiftedValue propagating shift through expression"
" to eliminate shift:\n IN: " << *Op0 << "\n SH: "
<< I << "\n"; } } while (false)
785 << *Op0 << "\n SH: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("instcombine")) { dbgs() << "ICE: GetShiftedValue propagating shift through expression"
" to eliminate shift:\n IN: " << *Op0 << "\n SH: "
<< I << "\n"; } } while (false)
;
786
787 return replaceInstUsesWith(
788 I, getShiftedValue(Op0, Op1C->getZExtValue(), IsLeftShift, *this, DL));
789 }
790
791 if (Instruction *FoldedShift = foldBinOpIntoSelectOrPhi(I))
792 return FoldedShift;
793
794 if (!Op0->hasOneUse())
795 return nullptr;
796
797 if (auto *Op0BO = dyn_cast<BinaryOperator>(Op0)) {
798 // If the operand is a bitwise operator with a constant RHS, and the
799 // shift is the only use, we can pull it out of the shift.
800 const APInt *Op0C;
801 if (match(Op0BO->getOperand(1), m_APInt(Op0C))) {
802 if (canShiftBinOpWithConstantRHS(I, Op0BO)) {
803 Value *NewRHS =
804 Builder.CreateBinOp(I.getOpcode(), Op0BO->getOperand(1), C1);
805
806 Value *NewShift =
807 Builder.CreateBinOp(I.getOpcode(), Op0BO->getOperand(0), C1);
808 NewShift->takeName(Op0BO);
809
810 return BinaryOperator::Create(Op0BO->getOpcode(), NewShift, NewRHS);
811 }
812 }
813 }
814
815 // If we have a select that conditionally executes some binary operator,
816 // see if we can pull it the select and operator through the shift.
817 //
818 // For example, turning:
819 // shl (select C, (add X, C1), X), C2
820 // Into:
821 // Y = shl X, C2
822 // select C, (add Y, C1 << C2), Y
823 Value *Cond;
824 BinaryOperator *TBO;
825 Value *FalseVal;
826 if (match(Op0, m_Select(m_Value(Cond), m_OneUse(m_BinOp(TBO)),
827 m_Value(FalseVal)))) {
828 const APInt *C;
829 if (!isa<Constant>(FalseVal) && TBO->getOperand(0) == FalseVal &&
830 match(TBO->getOperand(1), m_APInt(C)) &&
831 canShiftBinOpWithConstantRHS(I, TBO)) {
832 Value *NewRHS =
833 Builder.CreateBinOp(I.getOpcode(), TBO->getOperand(1), C1);
834
835 Value *NewShift = Builder.CreateBinOp(I.getOpcode(), FalseVal, C1);
836 Value *NewOp = Builder.CreateBinOp(TBO->getOpcode(), NewShift, NewRHS);
837 return SelectInst::Create(Cond, NewOp, NewShift);
838 }
839 }
840
841 BinaryOperator *FBO;
842 Value *TrueVal;
843 if (match(Op0, m_Select(m_Value(Cond), m_Value(TrueVal),
844 m_OneUse(m_BinOp(FBO))))) {
845 const APInt *C;
846 if (!isa<Constant>(TrueVal) && FBO->getOperand(0) == TrueVal &&
847 match(FBO->getOperand(1), m_APInt(C)) &&
848 canShiftBinOpWithConstantRHS(I, FBO)) {
849 Value *NewRHS =
850 Builder.CreateBinOp(I.getOpcode(), FBO->getOperand(1), C1);
851
852 Value *NewShift = Builder.CreateBinOp(I.getOpcode(), TrueVal, C1);
853 Value *NewOp = Builder.CreateBinOp(FBO->getOpcode(), NewShift, NewRHS);
854 return SelectInst::Create(Cond, NewShift, NewOp);
855 }
856 }
857
858 return nullptr;
859}
860
861// Tries to perform
862// (lshr (add (zext X), (zext Y)), K)
863// -> (icmp ult (add X, Y), X)
864// where
865// - The add's operands are zexts from a K-bits integer to a bigger type.
866// - The add is only used by the shr, or by iK (or narrower) truncates.
867// - The lshr type has more than 2 bits (other types are boolean math).
868// - K > 1
869// note that
870// - The resulting add cannot have nuw/nsw, else on overflow we get a
871// poison value and the transform isn't legal anymore.
872Instruction *InstCombinerImpl::foldLShrOverflowBit(BinaryOperator &I) {
873 assert(I.getOpcode() == Instruction::LShr)(static_cast <bool> (I.getOpcode() == Instruction::LShr
) ? void (0) : __assert_fail ("I.getOpcode() == Instruction::LShr"
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 873
, __extension__ __PRETTY_FUNCTION__))
;
874
875 Value *Add = I.getOperand(0);
876 Value *ShiftAmt = I.getOperand(1);
877 Type *Ty = I.getType();
878
879 if (Ty->getScalarSizeInBits() < 3)
880 return nullptr;
881
882 const APInt *ShAmtAPInt = nullptr;
883 Value *X = nullptr, *Y = nullptr;
884 if (!match(ShiftAmt, m_APInt(ShAmtAPInt)) ||
885 !match(Add,
886 m_Add(m_OneUse(m_ZExt(m_Value(X))), m_OneUse(m_ZExt(m_Value(Y))))))
887 return nullptr;
888
889 const unsigned ShAmt = ShAmtAPInt->getZExtValue();
890 if (ShAmt == 1)
891 return nullptr;
892
893 // X/Y are zexts from `ShAmt`-sized ints.
894 if (X->getType()->getScalarSizeInBits() != ShAmt ||
895 Y->getType()->getScalarSizeInBits() != ShAmt)
896 return nullptr;
897
898 // Make sure that `Add` is only used by `I` and `ShAmt`-truncates.
899 if (!Add->hasOneUse()) {
900 for (User *U : Add->users()) {
901 if (U == &I)
902 continue;
903
904 TruncInst *Trunc = dyn_cast<TruncInst>(U);
905 if (!Trunc || Trunc->getType()->getScalarSizeInBits() > ShAmt)
906 return nullptr;
907 }
908 }
909
910 // Insert at Add so that the newly created `NarrowAdd` will dominate it's
911 // users (i.e. `Add`'s users).
912 Instruction *AddInst = cast<Instruction>(Add);
913 Builder.SetInsertPoint(AddInst);
914
915 Value *NarrowAdd = Builder.CreateAdd(X, Y, "add.narrowed");
916 Value *Overflow =
917 Builder.CreateICmpULT(NarrowAdd, X, "add.narrowed.overflow");
918
919 // Replace the uses of the original add with a zext of the
920 // NarrowAdd's result. Note that all users at this stage are known to
921 // be ShAmt-sized truncs, or the lshr itself.
922 if (!Add->hasOneUse())
923 replaceInstUsesWith(*AddInst, Builder.CreateZExt(NarrowAdd, Ty));
924
925 // Replace the LShr with a zext of the overflow check.
926 return new ZExtInst(Overflow, Ty);
927}
928
929Instruction *InstCombinerImpl::visitShl(BinaryOperator &I) {
930 const SimplifyQuery Q = SQ.getWithInstruction(&I);
931
932 if (Value *V = simplifyShlInst(I.getOperand(0), I.getOperand(1),
1
Assuming 'V' is null
2
Taking false branch
933 I.hasNoSignedWrap(), I.hasNoUnsignedWrap(), Q))
934 return replaceInstUsesWith(I, V);
935
936 if (Instruction *X = foldVectorBinop(I))
3
Assuming 'X' is null
4
Taking false branch
937 return X;
938
939 if (Instruction *V
4.1
'V' is null
4.1
'V' is null
= commonShiftTransforms(I))
5
Taking false branch
940 return V;
941
942 if (Instruction *V = dropRedundantMaskingOfLeftShiftInput(&I, Q, Builder))
6
Calling 'dropRedundantMaskingOfLeftShiftInput'
943 return V;
944
945 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
946 Type *Ty = I.getType();
947 unsigned BitWidth = Ty->getScalarSizeInBits();
948
949 const APInt *C;
950 if (match(Op1, m_APInt(C))) {
951 unsigned ShAmtC = C->getZExtValue();
952
953 // shl (zext X), C --> zext (shl X, C)
954 // This is only valid if X would have zeros shifted out.
955 Value *X;
956 if (match(Op0, m_OneUse(m_ZExt(m_Value(X))))) {
957 unsigned SrcWidth = X->getType()->getScalarSizeInBits();
958 if (ShAmtC < SrcWidth &&
959 MaskedValueIsZero(X, APInt::getHighBitsSet(SrcWidth, ShAmtC), 0, &I))
960 return new ZExtInst(Builder.CreateShl(X, ShAmtC), Ty);
961 }
962
963 // (X >> C) << C --> X & (-1 << C)
964 if (match(Op0, m_Shr(m_Value(X), m_Specific(Op1)))) {
965 APInt Mask(APInt::getHighBitsSet(BitWidth, BitWidth - ShAmtC));
966 return BinaryOperator::CreateAnd(X, ConstantInt::get(Ty, Mask));
967 }
968
969 const APInt *C1;
970 if (match(Op0, m_Exact(m_Shr(m_Value(X), m_APInt(C1)))) &&
971 C1->ult(BitWidth)) {
972 unsigned ShrAmt = C1->getZExtValue();
973 if (ShrAmt < ShAmtC) {
974 // If C1 < C: (X >>?,exact C1) << C --> X << (C - C1)
975 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmtC - ShrAmt);
976 auto *NewShl = BinaryOperator::CreateShl(X, ShiftDiff);
977 NewShl->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
978 NewShl->setHasNoSignedWrap(I.hasNoSignedWrap());
979 return NewShl;
980 }
981 if (ShrAmt > ShAmtC) {
982 // If C1 > C: (X >>?exact C1) << C --> X >>?exact (C1 - C)
983 Constant *ShiftDiff = ConstantInt::get(Ty, ShrAmt - ShAmtC);
984 auto *NewShr = BinaryOperator::Create(
985 cast<BinaryOperator>(Op0)->getOpcode(), X, ShiftDiff);
986 NewShr->setIsExact(true);
987 return NewShr;
988 }
989 }
990
991 if (match(Op0, m_OneUse(m_Shr(m_Value(X), m_APInt(C1)))) &&
992 C1->ult(BitWidth)) {
993 unsigned ShrAmt = C1->getZExtValue();
994 if (ShrAmt < ShAmtC) {
995 // If C1 < C: (X >>? C1) << C --> (X << (C - C1)) & (-1 << C)
996 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmtC - ShrAmt);
997 auto *NewShl = BinaryOperator::CreateShl(X, ShiftDiff);
998 NewShl->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
999 NewShl->setHasNoSignedWrap(I.hasNoSignedWrap());
1000 Builder.Insert(NewShl);
1001 APInt Mask(APInt::getHighBitsSet(BitWidth, BitWidth - ShAmtC));
1002 return BinaryOperator::CreateAnd(NewShl, ConstantInt::get(Ty, Mask));
1003 }
1004 if (ShrAmt > ShAmtC) {
1005 // If C1 > C: (X >>? C1) << C --> (X >>? (C1 - C)) & (-1 << C)
1006 Constant *ShiftDiff = ConstantInt::get(Ty, ShrAmt - ShAmtC);
1007 auto *OldShr = cast<BinaryOperator>(Op0);
1008 auto *NewShr =
1009 BinaryOperator::Create(OldShr->getOpcode(), X, ShiftDiff);
1010 NewShr->setIsExact(OldShr->isExact());
1011 Builder.Insert(NewShr);
1012 APInt Mask(APInt::getHighBitsSet(BitWidth, BitWidth - ShAmtC));
1013 return BinaryOperator::CreateAnd(NewShr, ConstantInt::get(Ty, Mask));
1014 }
1015 }
1016
1017 // Similar to above, but look through an intermediate trunc instruction.
1018 BinaryOperator *Shr;
1019 if (match(Op0, m_OneUse(m_Trunc(m_OneUse(m_BinOp(Shr))))) &&
1020 match(Shr, m_Shr(m_Value(X), m_APInt(C1)))) {
1021 // The larger shift direction survives through the transform.
1022 unsigned ShrAmtC = C1->getZExtValue();
1023 unsigned ShDiff = ShrAmtC > ShAmtC ? ShrAmtC - ShAmtC : ShAmtC - ShrAmtC;
1024 Constant *ShiftDiffC = ConstantInt::get(X->getType(), ShDiff);
1025 auto ShiftOpc = ShrAmtC > ShAmtC ? Shr->getOpcode() : Instruction::Shl;
1026
1027 // If C1 > C:
1028 // (trunc (X >> C1)) << C --> (trunc (X >> (C1 - C))) && (-1 << C)
1029 // If C > C1:
1030 // (trunc (X >> C1)) << C --> (trunc (X << (C - C1))) && (-1 << C)
1031 Value *NewShift = Builder.CreateBinOp(ShiftOpc, X, ShiftDiffC, "sh.diff");
1032 Value *Trunc = Builder.CreateTrunc(NewShift, Ty, "tr.sh.diff");
1033 APInt Mask(APInt::getHighBitsSet(BitWidth, BitWidth - ShAmtC));
1034 return BinaryOperator::CreateAnd(Trunc, ConstantInt::get(Ty, Mask));
1035 }
1036
1037 if (match(Op0, m_Shl(m_Value(X), m_APInt(C1))) && C1->ult(BitWidth)) {
1038 unsigned AmtSum = ShAmtC + C1->getZExtValue();
1039 // Oversized shifts are simplified to zero in InstSimplify.
1040 if (AmtSum < BitWidth)
1041 // (X << C1) << C2 --> X << (C1 + C2)
1042 return BinaryOperator::CreateShl(X, ConstantInt::get(Ty, AmtSum));
1043 }
1044
1045 // If we have an opposite shift by the same amount, we may be able to
1046 // reorder binops and shifts to eliminate math/logic.
1047 auto isSuitableBinOpcode = [](Instruction::BinaryOps BinOpcode) {
1048 switch (BinOpcode) {
1049 default:
1050 return false;
1051 case Instruction::Add:
1052 case Instruction::And:
1053 case Instruction::Or:
1054 case Instruction::Xor:
1055 case Instruction::Sub:
1056 // NOTE: Sub is not commutable and the tranforms below may not be valid
1057 // when the shift-right is operand 1 (RHS) of the sub.
1058 return true;
1059 }
1060 };
1061 BinaryOperator *Op0BO;
1062 if (match(Op0, m_OneUse(m_BinOp(Op0BO))) &&
1063 isSuitableBinOpcode(Op0BO->getOpcode())) {
1064 // Commute so shift-right is on LHS of the binop.
1065 // (Y bop (X >> C)) << C -> ((X >> C) bop Y) << C
1066 // (Y bop ((X >> C) & CC)) << C -> (((X >> C) & CC) bop Y) << C
1067 Value *Shr = Op0BO->getOperand(0);
1068 Value *Y = Op0BO->getOperand(1);
1069 Value *X;
1070 const APInt *CC;
1071 if (Op0BO->isCommutative() && Y->hasOneUse() &&
1072 (match(Y, m_Shr(m_Value(), m_Specific(Op1))) ||
1073 match(Y, m_And(m_OneUse(m_Shr(m_Value(), m_Specific(Op1))),
1074 m_APInt(CC)))))
1075 std::swap(Shr, Y);
1076
1077 // ((X >> C) bop Y) << C -> (X bop (Y << C)) & (~0 << C)
1078 if (match(Shr, m_OneUse(m_Shr(m_Value(X), m_Specific(Op1))))) {
1079 // Y << C
1080 Value *YS = Builder.CreateShl(Y, Op1, Op0BO->getName());
1081 // (X bop (Y << C))
1082 Value *B =
1083 Builder.CreateBinOp(Op0BO->getOpcode(), X, YS, Shr->getName());
1084 unsigned Op1Val = C->getLimitedValue(BitWidth);
1085 APInt Bits = APInt::getHighBitsSet(BitWidth, BitWidth - Op1Val);
1086 Constant *Mask = ConstantInt::get(Ty, Bits);
1087 return BinaryOperator::CreateAnd(B, Mask);
1088 }
1089
1090 // (((X >> C) & CC) bop Y) << C -> (X & (CC << C)) bop (Y << C)
1091 if (match(Shr,
1092 m_OneUse(m_And(m_OneUse(m_Shr(m_Value(X), m_Specific(Op1))),
1093 m_APInt(CC))))) {
1094 // Y << C
1095 Value *YS = Builder.CreateShl(Y, Op1, Op0BO->getName());
1096 // X & (CC << C)
1097 Value *M = Builder.CreateAnd(X, ConstantInt::get(Ty, CC->shl(*C)),
1098 X->getName() + ".mask");
1099 return BinaryOperator::Create(Op0BO->getOpcode(), M, YS);
1100 }
1101 }
1102
1103 // (C1 - X) << C --> (C1 << C) - (X << C)
1104 if (match(Op0, m_OneUse(m_Sub(m_APInt(C1), m_Value(X))))) {
1105 Constant *NewLHS = ConstantInt::get(Ty, C1->shl(*C));
1106 Value *NewShift = Builder.CreateShl(X, Op1);
1107 return BinaryOperator::CreateSub(NewLHS, NewShift);
1108 }
1109
1110 // If the shifted-out value is known-zero, then this is a NUW shift.
1111 if (!I.hasNoUnsignedWrap() &&
1112 MaskedValueIsZero(Op0, APInt::getHighBitsSet(BitWidth, ShAmtC), 0,
1113 &I)) {
1114 I.setHasNoUnsignedWrap();
1115 return &I;
1116 }
1117
1118 // If the shifted-out value is all signbits, then this is a NSW shift.
1119 if (!I.hasNoSignedWrap() && ComputeNumSignBits(Op0, 0, &I) > ShAmtC) {
1120 I.setHasNoSignedWrap();
1121 return &I;
1122 }
1123 }
1124
1125 // Transform (x >> y) << y to x & (-1 << y)
1126 // Valid for any type of right-shift.
1127 Value *X;
1128 if (match(Op0, m_OneUse(m_Shr(m_Value(X), m_Specific(Op1))))) {
1129 Constant *AllOnes = ConstantInt::getAllOnesValue(Ty);
1130 Value *Mask = Builder.CreateShl(AllOnes, Op1);
1131 return BinaryOperator::CreateAnd(Mask, X);
1132 }
1133
1134 Constant *C1;
1135 if (match(Op1, m_Constant(C1))) {
1136 Constant *C2;
1137 Value *X;
1138 // (X * C2) << C1 --> X * (C2 << C1)
1139 if (match(Op0, m_Mul(m_Value(X), m_Constant(C2))))
1140 return BinaryOperator::CreateMul(X, ConstantExpr::getShl(C2, C1));
1141
1142 // shl (zext i1 X), C1 --> select (X, 1 << C1, 0)
1143 if (match(Op0, m_ZExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1)) {
1144 auto *NewC = ConstantExpr::getShl(ConstantInt::get(Ty, 1), C1);
1145 return SelectInst::Create(X, NewC, ConstantInt::getNullValue(Ty));
1146 }
1147 }
1148
1149 if (match(Op0, m_One())) {
1150 // (1 << (C - x)) -> ((1 << C) >> x) if C is bitwidth - 1
1151 if (match(Op1, m_Sub(m_SpecificInt(BitWidth - 1), m_Value(X))))
1152 return BinaryOperator::CreateLShr(
1153 ConstantInt::get(Ty, APInt::getSignMask(BitWidth)), X);
1154
1155 // Canonicalize "extract lowest set bit" using cttz to and-with-negate:
1156 // 1 << (cttz X) --> -X & X
1157 if (match(Op1,
1158 m_OneUse(m_Intrinsic<Intrinsic::cttz>(m_Value(X), m_Value())))) {
1159 Value *NegX = Builder.CreateNeg(X, "neg");
1160 return BinaryOperator::CreateAnd(NegX, X);
1161 }
1162
1163 // The only way to shift out the 1 is with an over-shift, so that would
1164 // be poison with or without "nuw". Undef is excluded because (undef << X)
1165 // is not undef (it is zero).
1166 Constant *ConstantOne = cast<Constant>(Op0);
1167 if (!I.hasNoUnsignedWrap() && !ConstantOne->containsUndefElement()) {
1168 I.setHasNoUnsignedWrap();
1169 return &I;
1170 }
1171 }
1172
1173 return nullptr;
1174}
1175
1176Instruction *InstCombinerImpl::visitLShr(BinaryOperator &I) {
1177 if (Value *V = simplifyLShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
1178 SQ.getWithInstruction(&I)))
1179 return replaceInstUsesWith(I, V);
1180
1181 if (Instruction *X = foldVectorBinop(I))
1182 return X;
1183
1184 if (Instruction *R = commonShiftTransforms(I))
1185 return R;
1186
1187 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1188 Type *Ty = I.getType();
1189 Value *X;
1190 const APInt *C;
1191 unsigned BitWidth = Ty->getScalarSizeInBits();
1192
1193 // (iN (~X) u>> (N - 1)) --> zext (X > -1)
1194 if (match(Op0, m_OneUse(m_Not(m_Value(X)))) &&
1195 match(Op1, m_SpecificIntAllowUndef(BitWidth - 1)))
1196 return new ZExtInst(Builder.CreateIsNotNeg(X, "isnotneg"), Ty);
1197
1198 if (match(Op1, m_APInt(C))) {
1199 unsigned ShAmtC = C->getZExtValue();
1200 auto *II = dyn_cast<IntrinsicInst>(Op0);
1201 if (II && isPowerOf2_32(BitWidth) && Log2_32(BitWidth) == ShAmtC &&
1202 (II->getIntrinsicID() == Intrinsic::ctlz ||
1203 II->getIntrinsicID() == Intrinsic::cttz ||
1204 II->getIntrinsicID() == Intrinsic::ctpop)) {
1205 // ctlz.i32(x)>>5 --> zext(x == 0)
1206 // cttz.i32(x)>>5 --> zext(x == 0)
1207 // ctpop.i32(x)>>5 --> zext(x == -1)
1208 bool IsPop = II->getIntrinsicID() == Intrinsic::ctpop;
1209 Constant *RHS = ConstantInt::getSigned(Ty, IsPop ? -1 : 0);
1210 Value *Cmp = Builder.CreateICmpEQ(II->getArgOperand(0), RHS);
1211 return new ZExtInst(Cmp, Ty);
1212 }
1213
1214 Value *X;
1215 const APInt *C1;
1216 if (match(Op0, m_Shl(m_Value(X), m_APInt(C1))) && C1->ult(BitWidth)) {
1217 if (C1->ult(ShAmtC)) {
1218 unsigned ShlAmtC = C1->getZExtValue();
1219 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmtC - ShlAmtC);
1220 if (cast<BinaryOperator>(Op0)->hasNoUnsignedWrap()) {
1221 // (X <<nuw C1) >>u C --> X >>u (C - C1)
1222 auto *NewLShr = BinaryOperator::CreateLShr(X, ShiftDiff);
1223 NewLShr->setIsExact(I.isExact());
1224 return NewLShr;
1225 }
1226 if (Op0->hasOneUse()) {
1227 // (X << C1) >>u C --> (X >>u (C - C1)) & (-1 >> C)
1228 Value *NewLShr = Builder.CreateLShr(X, ShiftDiff, "", I.isExact());
1229 APInt Mask(APInt::getLowBitsSet(BitWidth, BitWidth - ShAmtC));
1230 return BinaryOperator::CreateAnd(NewLShr, ConstantInt::get(Ty, Mask));
1231 }
1232 } else if (C1->ugt(ShAmtC)) {
1233 unsigned ShlAmtC = C1->getZExtValue();
1234 Constant *ShiftDiff = ConstantInt::get(Ty, ShlAmtC - ShAmtC);
1235 if (cast<BinaryOperator>(Op0)->hasNoUnsignedWrap()) {
1236 // (X <<nuw C1) >>u C --> X <<nuw (C1 - C)
1237 auto *NewShl = BinaryOperator::CreateShl(X, ShiftDiff);
1238 NewShl->setHasNoUnsignedWrap(true);
1239 return NewShl;
1240 }
1241 if (Op0->hasOneUse()) {
1242 // (X << C1) >>u C --> X << (C1 - C) & (-1 >> C)
1243 Value *NewShl = Builder.CreateShl(X, ShiftDiff);
1244 APInt Mask(APInt::getLowBitsSet(BitWidth, BitWidth - ShAmtC));
1245 return BinaryOperator::CreateAnd(NewShl, ConstantInt::get(Ty, Mask));
1246 }
1247 } else {
1248 assert(*C1 == ShAmtC)(static_cast <bool> (*C1 == ShAmtC) ? void (0) : __assert_fail
("*C1 == ShAmtC", "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp"
, 1248, __extension__ __PRETTY_FUNCTION__))
;
1249 // (X << C) >>u C --> X & (-1 >>u C)
1250 APInt Mask(APInt::getLowBitsSet(BitWidth, BitWidth - ShAmtC));
1251 return BinaryOperator::CreateAnd(X, ConstantInt::get(Ty, Mask));
1252 }
1253 }
1254
1255 // ((X << C) + Y) >>u C --> (X + (Y >>u C)) & (-1 >>u C)
1256 // TODO: Consolidate with the more general transform that starts from shl
1257 // (the shifts are in the opposite order).
1258 Value *Y;
1259 if (match(Op0,
1260 m_OneUse(m_c_Add(m_OneUse(m_Shl(m_Value(X), m_Specific(Op1))),
1261 m_Value(Y))))) {
1262 Value *NewLshr = Builder.CreateLShr(Y, Op1);
1263 Value *NewAdd = Builder.CreateAdd(NewLshr, X);
1264 unsigned Op1Val = C->getLimitedValue(BitWidth);
1265 APInt Bits = APInt::getLowBitsSet(BitWidth, BitWidth - Op1Val);
1266 Constant *Mask = ConstantInt::get(Ty, Bits);
1267 return BinaryOperator::CreateAnd(NewAdd, Mask);
1268 }
1269
1270 if (match(Op0, m_OneUse(m_ZExt(m_Value(X)))) &&
1271 (!Ty->isIntegerTy() || shouldChangeType(Ty, X->getType()))) {
1272 assert(ShAmtC < X->getType()->getScalarSizeInBits() &&(static_cast <bool> (ShAmtC < X->getType()->getScalarSizeInBits
() && "Big shift not simplified to zero?") ? void (0)
: __assert_fail ("ShAmtC < X->getType()->getScalarSizeInBits() && \"Big shift not simplified to zero?\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 1273
, __extension__ __PRETTY_FUNCTION__))
1273 "Big shift not simplified to zero?")(static_cast <bool> (ShAmtC < X->getType()->getScalarSizeInBits
() && "Big shift not simplified to zero?") ? void (0)
: __assert_fail ("ShAmtC < X->getType()->getScalarSizeInBits() && \"Big shift not simplified to zero?\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 1273
, __extension__ __PRETTY_FUNCTION__))
;
1274 // lshr (zext iM X to iN), C --> zext (lshr X, C) to iN
1275 Value *NewLShr = Builder.CreateLShr(X, ShAmtC);
1276 return new ZExtInst(NewLShr, Ty);
1277 }
1278
1279 if (match(Op0, m_SExt(m_Value(X)))) {
1280 unsigned SrcTyBitWidth = X->getType()->getScalarSizeInBits();
1281 // lshr (sext i1 X to iN), C --> select (X, -1 >> C, 0)
1282 if (SrcTyBitWidth == 1) {
1283 auto *NewC = ConstantInt::get(
1284 Ty, APInt::getLowBitsSet(BitWidth, BitWidth - ShAmtC));
1285 return SelectInst::Create(X, NewC, ConstantInt::getNullValue(Ty));
1286 }
1287
1288 if ((!Ty->isIntegerTy() || shouldChangeType(Ty, X->getType())) &&
1289 Op0->hasOneUse()) {
1290 // Are we moving the sign bit to the low bit and widening with high
1291 // zeros? lshr (sext iM X to iN), N-1 --> zext (lshr X, M-1) to iN
1292 if (ShAmtC == BitWidth - 1) {
1293 Value *NewLShr = Builder.CreateLShr(X, SrcTyBitWidth - 1);
1294 return new ZExtInst(NewLShr, Ty);
1295 }
1296
1297 // lshr (sext iM X to iN), N-M --> zext (ashr X, min(N-M, M-1)) to iN
1298 if (ShAmtC == BitWidth - SrcTyBitWidth) {
1299 // The new shift amount can't be more than the narrow source type.
1300 unsigned NewShAmt = std::min(ShAmtC, SrcTyBitWidth - 1);
1301 Value *AShr = Builder.CreateAShr(X, NewShAmt);
1302 return new ZExtInst(AShr, Ty);
1303 }
1304 }
1305 }
1306
1307 if (ShAmtC == BitWidth - 1) {
1308 // lshr i32 or(X,-X), 31 --> zext (X != 0)
1309 if (match(Op0, m_OneUse(m_c_Or(m_Neg(m_Value(X)), m_Deferred(X)))))
1310 return new ZExtInst(Builder.CreateIsNotNull(X), Ty);
1311
1312 // lshr i32 (X -nsw Y), 31 --> zext (X < Y)
1313 if (match(Op0, m_OneUse(m_NSWSub(m_Value(X), m_Value(Y)))))
1314 return new ZExtInst(Builder.CreateICmpSLT(X, Y), Ty);
1315
1316 // Check if a number is negative and odd:
1317 // lshr i32 (srem X, 2), 31 --> and (X >> 31), X
1318 if (match(Op0, m_OneUse(m_SRem(m_Value(X), m_SpecificInt(2))))) {
1319 Value *Signbit = Builder.CreateLShr(X, ShAmtC);
1320 return BinaryOperator::CreateAnd(Signbit, X);
1321 }
1322 }
1323
1324 // (X >>u C1) >>u C --> X >>u (C1 + C)
1325 if (match(Op0, m_LShr(m_Value(X), m_APInt(C1)))) {
1326 // Oversized shifts are simplified to zero in InstSimplify.
1327 unsigned AmtSum = ShAmtC + C1->getZExtValue();
1328 if (AmtSum < BitWidth)
1329 return BinaryOperator::CreateLShr(X, ConstantInt::get(Ty, AmtSum));
1330 }
1331
1332 Instruction *TruncSrc;
1333 if (match(Op0, m_OneUse(m_Trunc(m_Instruction(TruncSrc)))) &&
1334 match(TruncSrc, m_LShr(m_Value(X), m_APInt(C1)))) {
1335 unsigned SrcWidth = X->getType()->getScalarSizeInBits();
1336 unsigned AmtSum = ShAmtC + C1->getZExtValue();
1337
1338 // If the combined shift fits in the source width:
1339 // (trunc (X >>u C1)) >>u C --> and (trunc (X >>u (C1 + C)), MaskC
1340 //
1341 // If the first shift covers the number of bits truncated, then the
1342 // mask instruction is eliminated (and so the use check is relaxed).
1343 if (AmtSum < SrcWidth &&
1344 (TruncSrc->hasOneUse() || C1->uge(SrcWidth - BitWidth))) {
1345 Value *SumShift = Builder.CreateLShr(X, AmtSum, "sum.shift");
1346 Value *Trunc = Builder.CreateTrunc(SumShift, Ty, I.getName());
1347
1348 // If the first shift does not cover the number of bits truncated, then
1349 // we require a mask to get rid of high bits in the result.
1350 APInt MaskC = APInt::getAllOnes(BitWidth).lshr(ShAmtC);
1351 return BinaryOperator::CreateAnd(Trunc, ConstantInt::get(Ty, MaskC));
1352 }
1353 }
1354
1355 const APInt *MulC;
1356 if (match(Op0, m_NUWMul(m_Value(X), m_APInt(MulC)))) {
1357 // Look for a "splat" mul pattern - it replicates bits across each half of
1358 // a value, so a right shift is just a mask of the low bits:
1359 // lshr i[2N] (mul nuw X, (2^N)+1), N --> and iN X, (2^N)-1
1360 // TODO: Generalize to allow more than just half-width shifts?
1361 if (BitWidth > 2 && ShAmtC * 2 == BitWidth && (*MulC - 1).isPowerOf2() &&
1362 MulC->logBase2() == ShAmtC)
1363 return BinaryOperator::CreateAnd(X, ConstantInt::get(Ty, *MulC - 2));
1364
1365 // The one-use check is not strictly necessary, but codegen may not be
1366 // able to invert the transform and perf may suffer with an extra mul
1367 // instruction.
1368 if (Op0->hasOneUse()) {
1369 APInt NewMulC = MulC->lshr(ShAmtC);
1370 // if c is divisible by (1 << ShAmtC):
1371 // lshr (mul nuw x, MulC), ShAmtC -> mul nuw x, (MulC >> ShAmtC)
1372 if (MulC->eq(NewMulC.shl(ShAmtC))) {
1373 auto *NewMul =
1374 BinaryOperator::CreateNUWMul(X, ConstantInt::get(Ty, NewMulC));
1375 BinaryOperator *OrigMul = cast<BinaryOperator>(Op0);
1376 NewMul->setHasNoSignedWrap(OrigMul->hasNoSignedWrap());
1377 return NewMul;
1378 }
1379 }
1380 }
1381
1382 // Try to narrow bswap.
1383 // In the case where the shift amount equals the bitwidth difference, the
1384 // shift is eliminated.
1385 if (match(Op0, m_OneUse(m_Intrinsic<Intrinsic::bswap>(
1386 m_OneUse(m_ZExt(m_Value(X))))))) {
1387 unsigned SrcWidth = X->getType()->getScalarSizeInBits();
1388 unsigned WidthDiff = BitWidth - SrcWidth;
1389 if (SrcWidth % 16 == 0) {
1390 Value *NarrowSwap = Builder.CreateUnaryIntrinsic(Intrinsic::bswap, X);
1391 if (ShAmtC >= WidthDiff) {
1392 // (bswap (zext X)) >> C --> zext (bswap X >> C')
1393 Value *NewShift = Builder.CreateLShr(NarrowSwap, ShAmtC - WidthDiff);
1394 return new ZExtInst(NewShift, Ty);
1395 } else {
1396 // (bswap (zext X)) >> C --> (zext (bswap X)) << C'
1397 Value *NewZExt = Builder.CreateZExt(NarrowSwap, Ty);
1398 Constant *ShiftDiff = ConstantInt::get(Ty, WidthDiff - ShAmtC);
1399 return BinaryOperator::CreateShl(NewZExt, ShiftDiff);
1400 }
1401 }
1402 }
1403
1404 // Reduce add-carry of bools to logic:
1405 // ((zext BoolX) + (zext BoolY)) >> 1 --> zext (BoolX && BoolY)
1406 Value *BoolX, *BoolY;
1407 if (ShAmtC == 1 && match(Op0, m_Add(m_Value(X), m_Value(Y))) &&
1408 match(X, m_ZExt(m_Value(BoolX))) && match(Y, m_ZExt(m_Value(BoolY))) &&
1409 BoolX->getType()->isIntOrIntVectorTy(1) &&
1410 BoolY->getType()->isIntOrIntVectorTy(1) &&
1411 (X->hasOneUse() || Y->hasOneUse() || Op0->hasOneUse())) {
1412 Value *And = Builder.CreateAnd(BoolX, BoolY);
1413 return new ZExtInst(And, Ty);
1414 }
1415
1416 // If the shifted-out value is known-zero, then this is an exact shift.
1417 if (!I.isExact() &&
1418 MaskedValueIsZero(Op0, APInt::getLowBitsSet(BitWidth, ShAmtC), 0, &I)) {
1419 I.setIsExact();
1420 return &I;
1421 }
1422 }
1423
1424 // Transform (x << y) >> y to x & (-1 >> y)
1425 if (match(Op0, m_OneUse(m_Shl(m_Value(X), m_Specific(Op1))))) {
1426 Constant *AllOnes = ConstantInt::getAllOnesValue(Ty);
1427 Value *Mask = Builder.CreateLShr(AllOnes, Op1);
1428 return BinaryOperator::CreateAnd(Mask, X);
1429 }
1430
1431 if (Instruction *Overflow = foldLShrOverflowBit(I))
1432 return Overflow;
1433
1434 return nullptr;
1435}
1436
1437Instruction *
1438InstCombinerImpl::foldVariableSignZeroExtensionOfVariableHighBitExtract(
1439 BinaryOperator &OldAShr) {
1440 assert(OldAShr.getOpcode() == Instruction::AShr &&(static_cast <bool> (OldAShr.getOpcode() == Instruction
::AShr && "Must be called with arithmetic right-shift instruction only."
) ? void (0) : __assert_fail ("OldAShr.getOpcode() == Instruction::AShr && \"Must be called with arithmetic right-shift instruction only.\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 1441
, __extension__ __PRETTY_FUNCTION__))
1441 "Must be called with arithmetic right-shift instruction only.")(static_cast <bool> (OldAShr.getOpcode() == Instruction
::AShr && "Must be called with arithmetic right-shift instruction only."
) ? void (0) : __assert_fail ("OldAShr.getOpcode() == Instruction::AShr && \"Must be called with arithmetic right-shift instruction only.\""
, "llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp", 1441
, __extension__ __PRETTY_FUNCTION__))
;
1442
1443 // Check that constant C is a splat of the element-wise bitwidth of V.
1444 auto BitWidthSplat = [](Constant *C, Value *V) {
1445 return match(
1446 C, m_SpecificInt_ICMP(ICmpInst::Predicate::ICMP_EQ,
1447 APInt(C->getType()->getScalarSizeInBits(),
1448 V->getType()->getScalarSizeInBits())));
1449 };
1450
1451 // It should look like variable-length sign-extension on the outside:
1452 // (Val << (bitwidth(Val)-Nbits)) a>> (bitwidth(Val)-Nbits)
1453 Value *NBits;
1454 Instruction *MaybeTrunc;
1455 Constant *C1, *C2;
1456 if (!match(&OldAShr,
1457 m_AShr(m_Shl(m_Instruction(MaybeTrunc),
1458 m_ZExtOrSelf(m_Sub(m_Constant(C1),
1459 m_ZExtOrSelf(m_Value(NBits))))),
1460 m_ZExtOrSelf(m_Sub(m_Constant(C2),
1461 m_ZExtOrSelf(m_Deferred(NBits)))))) ||
1462 !BitWidthSplat(C1, &OldAShr) || !BitWidthSplat(C2, &OldAShr))
1463 return nullptr;
1464
1465 // There may or may not be a truncation after outer two shifts.
1466 Instruction *HighBitExtract;
1467 match(MaybeTrunc, m_TruncOrSelf(m_Instruction(HighBitExtract)));
1468 bool HadTrunc = MaybeTrunc != HighBitExtract;
1469
1470 // And finally, the innermost part of the pattern must be a right-shift.
1471 Value *X, *NumLowBitsToSkip;
1472 if (!match(HighBitExtract, m_Shr(m_Value(X), m_Value(NumLowBitsToSkip))))
1473 return nullptr;
1474
1475 // Said right-shift must extract high NBits bits - C0 must be it's bitwidth.
1476 Constant *C0;
1477 if (!match(NumLowBitsToSkip,
1478 m_ZExtOrSelf(
1479 m_Sub(m_Constant(C0), m_ZExtOrSelf(m_Specific(NBits))))) ||
1480 !BitWidthSplat(C0, HighBitExtract))
1481 return nullptr;
1482
1483 // Since the NBits is identical for all shifts, if the outermost and
1484 // innermost shifts are identical, then outermost shifts are redundant.
1485 // If we had truncation, do keep it though.
1486 if (HighBitExtract->getOpcode() == OldAShr.getOpcode())
1487 return replaceInstUsesWith(OldAShr, MaybeTrunc);
1488
1489 // Else, if there was a truncation, then we need to ensure that one
1490 // instruction will go away.
1491 if (HadTrunc && !match(&OldAShr, m_c_BinOp(m_OneUse(m_Value()), m_Value())))
1492 return nullptr;
1493
1494 // Finally, bypass two innermost shifts, and perform the outermost shift on
1495 // the operands of the innermost shift.
1496 Instruction *NewAShr =
1497 BinaryOperator::Create(OldAShr.getOpcode(), X, NumLowBitsToSkip);
1498 NewAShr->copyIRFlags(HighBitExtract); // We can preserve 'exact'-ness.
1499 if (!HadTrunc)
1500 return NewAShr;
1501
1502 Builder.Insert(NewAShr);
1503 return TruncInst::CreateTruncOrBitCast(NewAShr, OldAShr.getType());
1504}
1505
1506Instruction *InstCombinerImpl::visitAShr(BinaryOperator &I) {
1507 if (Value *V = simplifyAShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
1508 SQ.getWithInstruction(&I)))
1509 return replaceInstUsesWith(I, V);
1510
1511 if (Instruction *X = foldVectorBinop(I))
1512 return X;
1513
1514 if (Instruction *R = commonShiftTransforms(I))
1515 return R;
1516
1517 Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
1518 Type *Ty = I.getType();
1519 unsigned BitWidth = Ty->getScalarSizeInBits();
1520 const APInt *ShAmtAPInt;
1521 if (match(Op1, m_APInt(ShAmtAPInt)) && ShAmtAPInt->ult(BitWidth)) {
1522 unsigned ShAmt = ShAmtAPInt->getZExtValue();
1523
1524 // If the shift amount equals the difference in width of the destination
1525 // and source scalar types:
1526 // ashr (shl (zext X), C), C --> sext X
1527 Value *X;
1528 if (match(Op0, m_Shl(m_ZExt(m_Value(X)), m_Specific(Op1))) &&
1529 ShAmt == BitWidth - X->getType()->getScalarSizeInBits())
1530 return new SExtInst(X, Ty);
1531
1532 // We can't handle (X << C1) >>s C2. It shifts arbitrary bits in. However,
1533 // we can handle (X <<nsw C1) >>s C2 since it only shifts in sign bits.
1534 const APInt *ShOp1;
1535 if (match(Op0, m_NSWShl(m_Value(X), m_APInt(ShOp1))) &&
1536 ShOp1->ult(BitWidth)) {
1537 unsigned ShlAmt = ShOp1->getZExtValue();
1538 if (ShlAmt < ShAmt) {
1539 // (X <<nsw C1) >>s C2 --> X >>s (C2 - C1)
1540 Constant *ShiftDiff = ConstantInt::get(Ty, ShAmt - ShlAmt);
1541 auto *NewAShr = BinaryOperator::CreateAShr(X, ShiftDiff);
1542 NewAShr->setIsExact(I.isExact());
1543 return NewAShr;
1544 }
1545 if (ShlAmt > ShAmt) {
1546 // (X <<nsw C1) >>s C2 --> X <<nsw (C1 - C2)
1547 Constant *ShiftDiff = ConstantInt::get(Ty, ShlAmt - ShAmt);
1548 auto *NewShl = BinaryOperator::Create(Instruction::Shl, X, ShiftDiff);
1549 NewShl->setHasNoSignedWrap(true);
1550 return NewShl;
1551 }
1552 }
1553
1554 if (match(Op0, m_AShr(m_Value(X), m_APInt(ShOp1))) &&
1555 ShOp1->ult(BitWidth)) {
1556 unsigned AmtSum = ShAmt + ShOp1->getZExtValue();
1557 // Oversized arithmetic shifts replicate the sign bit.
1558 AmtSum = std::min(AmtSum, BitWidth - 1);
1559 // (X >>s C1) >>s C2 --> X >>s (C1 + C2)
1560 return BinaryOperator::CreateAShr(X, ConstantInt::get(Ty, AmtSum));
1561 }
1562
1563 if (match(Op0, m_OneUse(m_SExt(m_Value(X)))) &&
1564 (Ty->isVectorTy() || shouldChangeType(Ty, X->getType()))) {
1565 // ashr (sext X), C --> sext (ashr X, C')
1566 Type *SrcTy = X->getType();
1567 ShAmt = std::min(ShAmt, SrcTy->getScalarSizeInBits() - 1);
1568 Value *NewSh = Builder.CreateAShr(X, ConstantInt::get(SrcTy, ShAmt));
1569 return new SExtInst(NewSh, Ty);
1570 }
1571
1572 if (ShAmt == BitWidth - 1) {
1573 // ashr i32 or(X,-X), 31 --> sext (X != 0)
1574 if (match(Op0, m_OneUse(m_c_Or(m_Neg(m_Value(X)), m_Deferred(X)))))
1575 return new SExtInst(Builder.CreateIsNotNull(X), Ty);
1576
1577 // ashr i32 (X -nsw Y), 31 --> sext (X < Y)
1578 Value *Y;
1579 if (match(Op0, m_OneUse(m_NSWSub(m_Value(X), m_Value(Y)))))
1580 return new SExtInst(Builder.CreateICmpSLT(X, Y), Ty);
1581 }
1582
1583 // If the shifted-out value is known-zero, then this is an exact shift.
1584 if (!I.isExact() &&
1585 MaskedValueIsZero(Op0, APInt::getLowBitsSet(BitWidth, ShAmt), 0, &I)) {
1586 I.setIsExact();
1587 return &I;
1588 }
1589 }
1590
1591 // Prefer `-(x & 1)` over `(x << (bitwidth(x)-1)) a>> (bitwidth(x)-1)`
1592 // as the pattern to splat the lowest bit.
1593 // FIXME: iff X is already masked, we don't need the one-use check.
1594 Value *X;
1595 if (match(Op1, m_SpecificIntAllowUndef(BitWidth - 1)) &&
1596 match(Op0, m_OneUse(m_Shl(m_Value(X),
1597 m_SpecificIntAllowUndef(BitWidth - 1))))) {
1598 Constant *Mask = ConstantInt::get(Ty, 1);
1599 // Retain the knowledge about the ignored lanes.
1600 Mask = Constant::mergeUndefsWith(
1601 Constant::mergeUndefsWith(Mask, cast<Constant>(Op1)),
1602 cast<Constant>(cast<Instruction>(Op0)->getOperand(1)));
1603 X = Builder.CreateAnd(X, Mask);
1604 return BinaryOperator::CreateNeg(X);
1605 }
1606
1607 if (Instruction *R = foldVariableSignZeroExtensionOfVariableHighBitExtract(I))
1608 return R;
1609
1610 // See if we can turn a signed shr into an unsigned shr.
1611 if (MaskedValueIsZero(Op0, APInt::getSignMask(BitWidth), 0, &I)) {
1612 Instruction *Lshr = BinaryOperator::CreateLShr(Op0, Op1);
1613 Lshr->setIsExact(I.isExact());
1614 return Lshr;
1615 }
1616
1617 // ashr (xor %x, -1), %y --> xor (ashr %x, %y), -1
1618 if (match(Op0, m_OneUse(m_Not(m_Value(X))))) {
1619 // Note that we must drop 'exact'-ness of the shift!
1620 // Note that we can't keep undef's in -1 vector constant!
1621 auto *NewAShr = Builder.CreateAShr(X, Op1, Op0->getName() + ".not");
1622 return BinaryOperator::CreateNot(NewAShr);
1623 }
1624
1625 return nullptr;
1626}

/build/source/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);
19
Returning without writing to 'P.L.VR'
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() {
140 return class_match<PoisonValue>();
141}
142
143/// Match an arbitrary Constant and ignore it.
144inline class_match<Constant> m_Constant() { return class_match<Constant>(); }
145
146/// Match an arbitrary ConstantInt and ignore it.
147inline class_match<ConstantInt> m_ConstantInt() {
148 return class_match<ConstantInt>();
149}
150
151/// Match an arbitrary ConstantFP and ignore it.
152inline class_match<ConstantFP> m_ConstantFP() {
153 return class_match<ConstantFP>();
154}
155
156struct constantexpr_match {
157 template <typename ITy> bool match(ITy *V) {
158 auto *C = dyn_cast<Constant>(V);
159 return C && (isa<ConstantExpr>(C) || C->containsConstantExpression());
160 }
161};
162
163/// Match a constant expression or a constant that contains a constant
164/// expression.
165inline constantexpr_match m_ConstantExpr() { return constantexpr_match(); }
166
167/// Match an arbitrary basic block value and ignore it.
168inline class_match<BasicBlock> m_BasicBlock() {
169 return class_match<BasicBlock>();
170}
171
172/// Inverting matcher
173template <typename Ty> struct match_unless {
174 Ty M;
175
176 match_unless(const Ty &Matcher) : M(Matcher) {}
177
178 template <typename ITy> bool match(ITy *V) { return !M.match(V); }
179};
180
181/// Match if the inner matcher does *NOT* match.
182template <typename Ty> inline match_unless<Ty> m_Unless(const Ty &M) {
183 return match_unless<Ty>(M);
184}
185
186/// Matching combinators
187template <typename LTy, typename RTy> struct match_combine_or {
188 LTy L;
189 RTy R;
190
191 match_combine_or(const LTy &Left, const RTy &Right) : L(Left), R(Right) {}
192
193 template <typename ITy> bool match(ITy *V) {
194 if (L.match(V))
195 return true;
196 if (R.match(V))
197 return true;
198 return false;
199 }
200};
201
202template <typename LTy, typename RTy> struct match_combine_and {
203 LTy L;
204 RTy R;
205
206 match_combine_and(const LTy &Left, const RTy &Right) : L(Left), R(Right) {}
207
208 template <typename ITy> bool match(ITy *V) {
209 if (L.match(V))
210 if (R.match(V))
211 return true;
212 return false;
213 }
214};
215
216/// Combine two pattern matchers matching L || R
217template <typename LTy, typename RTy>
218inline match_combine_or<LTy, RTy> m_CombineOr(const LTy &L, const RTy &R) {
219 return match_combine_or<LTy, RTy>(L, R);
220}
221
222/// Combine two pattern matchers matching L && R
223template <typename LTy, typename RTy>
224inline match_combine_and<LTy, RTy> m_CombineAnd(const LTy &L, const RTy &R) {
225 return match_combine_and<LTy, RTy>(L, R);
30
Returning without writing to 'L.Op.VR'
226}
227
228struct apint_match {
229 const APInt *&Res;
230 bool AllowUndef;
231
232 apint_match(const APInt *&Res, bool AllowUndef)
233 : Res(Res), AllowUndef(AllowUndef) {}
234
235 template <typename ITy> bool match(ITy *V) {
236 if (auto *CI = dyn_cast<ConstantInt>(V)) {
237 Res = &CI->getValue();
238 return true;
239 }
240 if (V->getType()->isVectorTy())
241 if (const auto *C = dyn_cast<Constant>(V))
242 if (auto *CI =
243 dyn_cast_or_null<ConstantInt>(C->getSplatValue(AllowUndef))) {
244 Res = &CI->getValue();
245 return true;
246 }
247 return false;
248 }
249};
250// Either constexpr if or renaming ConstantFP::getValueAPF to
251// ConstantFP::getValue is needed to do it via single template
252// function for both apint/apfloat.
253struct apfloat_match {
254 const APFloat *&Res;
255 bool AllowUndef;
256
257 apfloat_match(const APFloat *&Res, bool AllowUndef)
258 : Res(Res), AllowUndef(AllowUndef) {}
259
260 template <typename ITy> bool match(ITy *V) {
261 if (auto *CI = dyn_cast<ConstantFP>(V)) {
262 Res = &CI->getValueAPF();
263 return true;
264 }
265 if (V->getType()->isVectorTy())
266 if (const auto *C = dyn_cast<Constant>(V))
267 if (auto *CI =
268 dyn_cast_or_null<ConstantFP>(C->getSplatValue(AllowUndef))) {
269 Res = &CI->getValueAPF();
270 return true;
271 }
272 return false;
273 }
274};
275
276/// Match a ConstantInt or splatted ConstantVector, binding the
277/// specified pointer to the contained APInt.
278inline apint_match m_APInt(const APInt *&Res) {
279 // Forbid undefs by default to maintain previous behavior.
280 return apint_match(Res, /* AllowUndef */ false);
281}
282
283/// Match APInt while allowing undefs in splat vector constants.
284inline apint_match m_APIntAllowUndef(const APInt *&Res) {
285 return apint_match(Res, /* AllowUndef */ true);
286}
287
288/// Match APInt while forbidding undefs in splat vector constants.
289inline apint_match m_APIntForbidUndef(const APInt *&Res) {
290 return apint_match(Res, /* AllowUndef */ false);
291}
292
293/// Match a ConstantFP or splatted ConstantVector, binding the
294/// specified pointer to the contained APFloat.
295inline apfloat_match m_APFloat(const APFloat *&Res) {
296 // Forbid undefs by default to maintain previous behavior.
297 return apfloat_match(Res, /* AllowUndef */ false);
298}
299
300/// Match APFloat while allowing undefs in splat vector constants.
301inline apfloat_match m_APFloatAllowUndef(const APFloat *&Res) {
302 return apfloat_match(Res, /* AllowUndef */ true);
303}
304
305/// Match APFloat while forbidding undefs in splat vector constants.
306inline apfloat_match m_APFloatForbidUndef(const APFloat *&Res) {
307 return apfloat_match(Res, /* AllowUndef */ false);
308}
309
310template <int64_t Val> struct constantint_match {
311 template <typename ITy> bool match(ITy *V) {
312 if (const auto *CI = dyn_cast<ConstantInt>(V)) {
313 const APInt &CIV = CI->getValue();
314 if (Val >= 0)
315 return CIV == static_cast<uint64_t>(Val);
316 // If Val is negative, and CI is shorter than it, truncate to the right
317 // number of bits. If it is larger, then we have to sign extend. Just
318 // compare their negated values.
319 return -CIV == -Val;
320 }
321 return false;
322 }
323};
324
325/// Match a ConstantInt with a specific value.
326template <int64_t Val> inline constantint_match<Val> m_ConstantInt() {
327 return constantint_match<Val>();
328}
329
330/// This helper class is used to match constant scalars, vector splats,
331/// and fixed width vectors that satisfy a specified predicate.
332/// For fixed width vector constants, undefined elements are ignored.
333template <typename Predicate, typename ConstantVal>
334struct cstval_pred_ty : public Predicate {
335 template <typename ITy> bool match(ITy *V) {
336 if (const auto *CV = dyn_cast<ConstantVal>(V))
337 return this->isValue(CV->getValue());
338 if (const auto *VTy = dyn_cast<VectorType>(V->getType())) {
339 if (const auto *C = dyn_cast<Constant>(V)) {
340 if (const auto *CV = dyn_cast_or_null<ConstantVal>(C->getSplatValue()))
341 return this->isValue(CV->getValue());
342
343 // Number of elements of a scalable vector unknown at compile time
344 auto *FVTy = dyn_cast<FixedVectorType>(VTy);
345 if (!FVTy)
346 return false;
347
348 // Non-splat vector constant: check each element for a match.
349 unsigned NumElts = FVTy->getNumElements();
350 assert(NumElts != 0 && "Constant vector with no elements?")(static_cast <bool> (NumElts != 0 && "Constant vector with no elements?"
) ? void (0) : __assert_fail ("NumElts != 0 && \"Constant vector with no elements?\""
, "llvm/include/llvm/IR/PatternMatch.h", 350, __extension__ __PRETTY_FUNCTION__
))
;
351 bool HasNonUndefElements = false;
352 for (unsigned i = 0; i != NumElts; ++i) {
353 Constant *Elt = C->getAggregateElement(i);
354 if (!Elt)
355 return false;
356 if (isa<UndefValue>(Elt))
357 continue;
358 auto *CV = dyn_cast<ConstantVal>(Elt);
359 if (!CV || !this->isValue(CV->getValue()))
360 return false;
361 HasNonUndefElements = true;
362 }
363 return HasNonUndefElements;
364 }
365 }
366 return false;
367 }
368};
369
370/// specialization of cstval_pred_ty for ConstantInt
371template <typename Predicate>
372using cst_pred_ty = cstval_pred_ty<Predicate, ConstantInt>;
373
374/// specialization of cstval_pred_ty for ConstantFP
375template <typename Predicate>
376using cstfp_pred_ty = cstval_pred_ty<Predicate, ConstantFP>;
377
378/// This helper class is used to match scalar and vector constants that
379/// satisfy a specified predicate, and bind them to an APInt.
380template <typename Predicate> struct api_pred_ty : public Predicate {
381 const APInt *&Res;
382
383 api_pred_ty(const APInt *&R) : Res(R) {}
384
385 template <typename ITy> bool match(ITy *V) {
386 if (const auto *CI = dyn_cast<ConstantInt>(V))
387 if (this->isValue(CI->getValue())) {
388 Res = &CI->getValue();
389 return true;
390 }
391 if (V->getType()->isVectorTy())
392 if (const auto *C = dyn_cast<Constant>(V))
393 if (auto *CI = dyn_cast_or_null<ConstantInt>(C->getSplatValue()))
394 if (this->isValue(CI->getValue())) {
395 Res = &CI->getValue();
396 return true;
397 }
398
399 return false;
400 }
401};
402
403/// This helper class is used to match scalar and vector constants that
404/// satisfy a specified predicate, and bind them to an APFloat.
405/// Undefs are allowed in splat vector constants.
406template <typename Predicate> struct apf_pred_ty : public Predicate {
407 const APFloat *&Res;
408
409 apf_pred_ty(const APFloat *&R) : Res(R) {}
410
411 template <typename ITy> bool match(ITy *V) {
412 if (const auto *CI = dyn_cast<ConstantFP>(V))
413 if (this->isValue(CI->getValue())) {
414 Res = &CI->getValue();
415 return true;
416 }
417 if (V->getType()->isVectorTy())
418 if (const auto *C = dyn_cast<Constant>(V))
419 if (auto *CI = dyn_cast_or_null<ConstantFP>(
420 C->getSplatValue(/* AllowUndef */ true)))
421 if (this->isValue(CI->getValue())) {
422 Res = &CI->getValue();
423 return true;
424 }
425
426 return false;
427 }
428};
429
430///////////////////////////////////////////////////////////////////////////////
431//
432// Encapsulate constant value queries for use in templated predicate matchers.
433// This allows checking if constants match using compound predicates and works
434// with vector constants, possibly with relaxed constraints. For example, ignore
435// undef values.
436//
437///////////////////////////////////////////////////////////////////////////////
438
439struct is_any_apint {
440 bool isValue(const APInt &C) { return true; }
441};
442/// Match an integer or vector with any integral constant.
443/// For vectors, this includes constants with undefined elements.
444inline cst_pred_ty<is_any_apint> m_AnyIntegralConstant() {
445 return cst_pred_ty<is_any_apint>();
446}
447
448struct is_all_ones {
449 bool isValue(const APInt &C) { return C.isAllOnes(); }
450};
451/// Match an integer or vector with all bits set.
452/// For vectors, this includes constants with undefined elements.
453inline cst_pred_ty<is_all_ones> m_AllOnes() {
454 return cst_pred_ty<is_all_ones>();
455}
456
457struct is_maxsignedvalue {
458 bool isValue(const APInt &C) { return C.isMaxSignedValue(); }
459};
460/// Match an integer or vector with values having all bits except for the high
461/// bit set (0x7f...).
462/// For vectors, this includes constants with undefined elements.
463inline cst_pred_ty<is_maxsignedvalue> m_MaxSignedValue() {
464 return cst_pred_ty<is_maxsignedvalue>();
465}
466inline api_pred_ty<is_maxsignedvalue> m_MaxSignedValue(const APInt *&V) {
467 return V;
468}
469
470struct is_negative {
471 bool isValue(const APInt &C) { return C.isNegative(); }
472};
473/// Match an integer or vector of negative values.
474/// For vectors, this includes constants with undefined elements.
475inline cst_pred_ty<is_negative> m_Negative() {
476 return cst_pred_ty<is_negative>();
477}
478inline api_pred_ty<is_negative> m_Negative(const APInt *&V) { return V; }
479
480struct is_nonnegative {
481 bool isValue(const APInt &C) { return C.isNonNegative(); }
482};
483/// Match an integer or vector of non-negative values.
484/// For vectors, this includes constants with undefined elements.
485inline cst_pred_ty<is_nonnegative> m_NonNegative() {
486 return cst_pred_ty<is_nonnegative>();
487}
488inline api_pred_ty<is_nonnegative> m_NonNegative(const APInt *&V) { return V; }
489
490struct is_strictlypositive {
491 bool isValue(const APInt &C) { return C.isStrictlyPositive(); }
492};
493/// Match an integer or vector of strictly positive values.
494/// For vectors, this includes constants with undefined elements.
495inline cst_pred_ty<is_strictlypositive> m_StrictlyPositive() {
496 return cst_pred_ty<is_strictlypositive>();
497}
498inline api_pred_ty<is_strictlypositive> m_StrictlyPositive(const APInt *&V) {
499 return V;
500}
501
502struct is_nonpositive {
503 bool isValue(const APInt &C) { return C.isNonPositive(); }
504};
505/// Match an integer or vector of non-positive values.
506/// For vectors, this includes constants with undefined elements.
507inline cst_pred_ty<is_nonpositive> m_NonPositive() {
508 return cst_pred_ty<is_nonpositive>();
509}
510inline api_pred_ty<is_nonpositive> m_NonPositive(const APInt *&V) { return V; }
511
512struct is_one {
513 bool isValue(const APInt &C) { return C.isOne(); }
514};
515/// Match an integer 1 or a vector with all elements equal to 1.
516/// For vectors, this includes constants with undefined elements.
517inline cst_pred_ty<is_one> m_One() { return cst_pred_ty<is_one>(); }
518
519struct is_zero_int {
520 bool isValue(const APInt &C) { return C.isZero(); }
521};
522/// Match an integer 0 or a vector with all elements equal to 0.
523/// For vectors, this includes constants with undefined elements.
524inline cst_pred_ty<is_zero_int> m_ZeroInt() {
525 return cst_pred_ty<is_zero_int>();
526}
527
528struct is_zero {
529 template <typename ITy> bool match(ITy *V) {
530 auto *C = dyn_cast<Constant>(V);
531 // FIXME: this should be able to do something for scalable vectors
532 return C && (C->isNullValue() || cst_pred_ty<is_zero_int>().match(C));
533 }
534};
535/// Match any null constant or a vector with all elements equal to 0.
536/// For vectors, this includes constants with undefined elements.
537inline is_zero m_Zero() { return is_zero(); }
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() { return cst_pred_ty<is_power2>(); }
545inline api_pred_ty<is_power2> m_Power2(const APInt *&V) { return V; }
546
547struct is_negated_power2 {
548 bool isValue(const APInt &C) { return C.isNegatedPowerOf2(); }
549};
550/// Match a integer or vector negated power-of-2.
551/// For vectors, this includes constants with undefined elements.
552inline cst_pred_ty<is_negated_power2> m_NegatedPower2() {
553 return cst_pred_ty<is_negated_power2>();
554}
555inline api_pred_ty<is_negated_power2> m_NegatedPower2(const APInt *&V) {
556 return V;
557}
558
559struct is_power2_or_zero {
560 bool isValue(const APInt &C) { return !C || C.isPowerOf2(); }
561};
562/// Match an integer or vector of 0 or power-of-2 values.
563/// For vectors, this includes constants with undefined elements.
564inline cst_pred_ty<is_power2_or_zero> m_Power2OrZero() {
565 return cst_pred_ty<is_power2_or_zero>();
566}
567inline api_pred_ty<is_power2_or_zero> m_Power2OrZero(const APInt *&V) {
568 return V;
569}
570
571struct is_sign_mask {
572 bool isValue(const APInt &C) { return C.isSignMask(); }
573};
574/// Match an integer or vector with only the sign bit(s) set.
575/// For vectors, this includes constants with undefined elements.
576inline cst_pred_ty<is_sign_mask> m_SignMask() {
577 return cst_pred_ty<is_sign_mask>();
578}
579
580struct is_lowbit_mask {
581 bool isValue(const APInt &C) { return C.isMask(); }
582};
583/// Match an integer or vector with only the low bit(s) set.
584/// For vectors, this includes constants with undefined elements.
585inline cst_pred_ty<is_lowbit_mask> m_LowBitMask() {
586 return cst_pred_ty<is_lowbit_mask>();
587}
588inline api_pred_ty<is_lowbit_mask> m_LowBitMask(const APInt *&V) { return V; }
589
590struct icmp_pred_with_threshold {
591 ICmpInst::Predicate Pred;
592 const APInt *Thr;
593 bool isValue(const APInt &C) { return ICmpInst::compare(C, *Thr, Pred); }
594};
595/// Match an integer or vector with every element comparing 'pred' (eg/ne/...)
596/// to Threshold. For vectors, this includes constants with undefined elements.
597inline cst_pred_ty<icmp_pred_with_threshold>
598m_SpecificInt_ICMP(ICmpInst::Predicate Predicate, const APInt &Threshold) {
599 cst_pred_ty<icmp_pred_with_threshold> P;
600 P.Pred = Predicate;
601 P.Thr = &Threshold;
602 return P;
603}
604
605struct is_nan {
606 bool isValue(const APFloat &C) { return C.isNaN(); }
607};
608/// Match an arbitrary NaN constant. This includes quiet and signalling nans.
609/// For vectors, this includes constants with undefined elements.
610inline cstfp_pred_ty<is_nan> m_NaN() { return cstfp_pred_ty<is_nan>(); }
611
612struct is_nonnan {
613 bool isValue(const APFloat &C) { return !C.isNaN(); }
614};
615/// Match a non-NaN FP constant.
616/// For vectors, this includes constants with undefined elements.
617inline cstfp_pred_ty<is_nonnan> m_NonNaN() {
618 return cstfp_pred_ty<is_nonnan>();
619}
620
621struct is_inf {
622 bool isValue(const APFloat &C) { return C.isInfinity(); }
623};
624/// Match a positive or negative infinity FP constant.
625/// For vectors, this includes constants with undefined elements.
626inline cstfp_pred_ty<is_inf> m_Inf() { return cstfp_pred_ty<is_inf>(); }
627
628struct is_noninf {
629 bool isValue(const APFloat &C) { return !C.isInfinity(); }
630};
631/// Match a non-infinity FP constant, i.e. finite or NaN.
632/// For vectors, this includes constants with undefined elements.
633inline cstfp_pred_ty<is_noninf> m_NonInf() {
634 return cstfp_pred_ty<is_noninf>();
635}
636
637struct is_finite {
638 bool isValue(const APFloat &C) { return C.isFinite(); }
639};
640/// Match a finite FP constant, i.e. not infinity or NaN.
641/// For vectors, this includes constants with undefined elements.
642inline cstfp_pred_ty<is_finite> m_Finite() {
643 return cstfp_pred_ty<is_finite>();
644}
645inline apf_pred_ty<is_finite> m_Finite(const APFloat *&V) { return V; }
646
647struct is_finitenonzero {
648 bool isValue(const APFloat &C) { return C.isFiniteNonZero(); }
649};
650/// Match a finite non-zero FP constant.
651/// For vectors, this includes constants with undefined elements.
652inline cstfp_pred_ty<is_finitenonzero> m_FiniteNonZero() {
653 return cstfp_pred_ty<is_finitenonzero>();
654}
655inline apf_pred_ty<is_finitenonzero> m_FiniteNonZero(const APFloat *&V) {
656 return V;
657}
658
659struct is_any_zero_fp {
660 bool isValue(const APFloat &C) { return C.isZero(); }
661};
662/// Match a floating-point negative zero or positive zero.
663/// For vectors, this includes constants with undefined elements.
664inline cstfp_pred_ty<is_any_zero_fp> m_AnyZeroFP() {
665 return cstfp_pred_ty<is_any_zero_fp>();
666}
667
668struct is_pos_zero_fp {
669 bool isValue(const APFloat &C) { return C.isPosZero(); }
670};
671/// Match a floating-point positive zero.
672/// For vectors, this includes constants with undefined elements.
673inline cstfp_pred_ty<is_pos_zero_fp> m_PosZeroFP() {
674 return cstfp_pred_ty<is_pos_zero_fp>();
675}
676
677struct is_neg_zero_fp {
678 bool isValue(const APFloat &C) { return C.isNegZero(); }
679};
680/// Match a floating-point negative zero.
681/// For vectors, this includes constants with undefined elements.
682inline cstfp_pred_ty<is_neg_zero_fp> m_NegZeroFP() {
683 return cstfp_pred_ty<is_neg_zero_fp>();
684}
685
686struct is_non_zero_fp {
687 bool isValue(const APFloat &C) { return C.isNonZero(); }
688};
689/// Match a floating-point non-zero.
690/// For vectors, this includes constants with undefined elements.
691inline cstfp_pred_ty<is_non_zero_fp> m_NonZeroFP() {
692 return cstfp_pred_ty<is_non_zero_fp>();
693}
694
695///////////////////////////////////////////////////////////////////////////////
696
697template <typename Class> struct bind_ty {
698 Class *&VR;
699
700 bind_ty(Class *&V) : VR(V) {}
701
702 template <typename ITy> bool match(ITy *V) {
703 if (auto *CV = dyn_cast<Class>(V)) {
704 VR = CV;
705 return true;
706 }
707 return false;
708 }
709};
710
711/// Match a value, capturing it if we match.
712inline bind_ty<Value> m_Value(Value *&V) { return V; }
11
Calling constructor for 'bind_ty<llvm::Value>'
12
Returning from constructor for 'bind_ty<llvm::Value>'
13
Returning without writing to 'V'
22
Calling constructor for 'bind_ty<llvm::Value>'
23
Returning from constructor for 'bind_ty<llvm::Value>'
24
Returning without writing to 'V'
713inline bind_ty<const Value> m_Value(const Value *&V) { return V; }
714
715/// Match an instruction, capturing it if we match.
716inline bind_ty<Instruction> m_Instruction(Instruction *&I) { return I; }
717/// Match a unary operator, capturing it if we match.
718inline bind_ty<UnaryOperator> m_UnOp(UnaryOperator *&I) { return I; }
719/// Match a binary operator, capturing it if we match.
720inline bind_ty<BinaryOperator> m_BinOp(BinaryOperator *&I) { return I; }
721/// Match a with overflow intrinsic, capturing it if we match.
722inline bind_ty<WithOverflowInst> m_WithOverflowInst(WithOverflowInst *&I) {
723 return I;
724}
725inline bind_ty<const WithOverflowInst>
726m_WithOverflowInst(const WithOverflowInst *&I) {
727 return I;
728}
729
730/// Match a Constant, capturing the value if we match.
731inline bind_ty<Constant> m_Constant(Constant *&C) { return C; }
732
733/// Match a ConstantInt, capturing the value if we match.
734inline bind_ty<ConstantInt> m_ConstantInt(ConstantInt *&CI) { return CI; }
735
736/// Match a ConstantFP, capturing the value if we match.
737inline bind_ty<ConstantFP> m_ConstantFP(ConstantFP *&C) { return C; }
738
739/// Match a ConstantExpr, capturing the value if we match.
740inline bind_ty<ConstantExpr> m_ConstantExpr(ConstantExpr *&C) { return C; }
741
742/// Match a basic block value, capturing it if we match.
743inline bind_ty<BasicBlock> m_BasicBlock(BasicBlock *&V) { return V; }
744inline bind_ty<const BasicBlock> m_BasicBlock(const BasicBlock *&V) {
745 return V;
746}
747
748/// Match an arbitrary immediate Constant and ignore it.
749inline match_combine_and<class_match<Constant>,
750 match_unless<constantexpr_match>>
751m_ImmConstant() {
752 return m_CombineAnd(m_Constant(), m_Unless(m_ConstantExpr()));
753}
754
755/// Match an immediate Constant, capturing the value if we match.
756inline match_combine_and<bind_ty<Constant>,
757 match_unless<constantexpr_match>>
758m_ImmConstant(Constant *&C) {
759 return m_CombineAnd(m_Constant(C), m_Unless(m_ConstantExpr()));
760}
761
762/// Match a specified Value*.
763struct specificval_ty {
764 const Value *Val;
765
766 specificval_ty(const Value *V) : Val(V) {}
767
768 template <typename ITy> bool match(ITy *V) { return V == Val; }
769};
770
771/// Match if we have a specific specified value.
772inline specificval_ty m_Specific(const Value *V) { return V; }
773
774/// Stores a reference to the Value *, not the Value * itself,
775/// thus can be used in commutative matchers.
776template <typename Class> struct deferredval_ty {
777 Class *const &Val;
778
779 deferredval_ty(Class *const &V) : Val(V) {}
780
781 template <typename ITy> bool match(ITy *const V) { return V == Val; }
782};
783
784/// Like m_Specific(), but works if the specific value to match is determined
785/// as part of the same match() expression. For example:
786/// m_Add(m_Value(X), m_Specific(X)) is incorrect, because m_Specific() will
787/// bind X before the pattern match starts.
788/// m_Add(m_Value(X), m_Deferred(X)) is correct, and will check against
789/// whichever value m_Value(X) populated.
790inline deferredval_ty<Value> m_Deferred(Value *const &V) { return V; }
791inline deferredval_ty<const Value> m_Deferred(const Value *const &V) {
792 return V;
793}
794
795/// Match a specified floating point value or vector of all elements of
796/// that value.
797struct specific_fpval {
798 double Val;
799
800 specific_fpval(double V) : Val(V) {}
801
802 template <typename ITy> bool match(ITy *V) {
803 if (const auto *CFP = dyn_cast<ConstantFP>(V))
804 return CFP->isExactlyValue(Val);
805 if (V->getType()->isVectorTy())
806 if (const auto *C = dyn_cast<Constant>(V))
807 if (auto *CFP = dyn_cast_or_null<ConstantFP>(C->getSplatValue()))
808 return CFP->isExactlyValue(Val);
809 return false;
810 }
811};
812
813/// Match a specific floating point value or vector with all elements
814/// equal to the value.
815inline specific_fpval m_SpecificFP(double V) { return specific_fpval(V); }
816
817/// Match a float 1.0 or vector with all elements equal to 1.0.
818inline specific_fpval m_FPOne() { return m_SpecificFP(1.0); }
819
820struct bind_const_intval_ty {
821 uint64_t &VR;
822
823 bind_const_intval_ty(uint64_t &V) : VR(V) {}
824
825 template <typename ITy> bool match(ITy *V) {
826 if (const auto *CV = dyn_cast<ConstantInt>(V))
827 if (CV->getValue().ule(UINT64_MAX(18446744073709551615UL))) {
828 VR = CV->getZExtValue();
829 return true;
830 }
831 return false;
832 }
833};
834
835/// Match a specified integer value or vector of all elements of that
836/// value.
837template <bool AllowUndefs> struct specific_intval {
838 APInt Val;
839
840 specific_intval(APInt V) : Val(std::move(V)) {}
841
842 template <typename ITy> bool match(ITy *V) {
843 const auto *CI = dyn_cast<ConstantInt>(V);
844 if (!CI && V->getType()->isVectorTy())
845 if (const auto *C = dyn_cast<Constant>(V))
846 CI = dyn_cast_or_null<ConstantInt>(C->getSplatValue(AllowUndefs));
847
848 return CI && APInt::isSameValue(CI->getValue(), Val);
849 }
850};
851
852/// Match a specific integer value or vector with all elements equal to
853/// the value.
854inline specific_intval<false> m_SpecificInt(APInt V) {
855 return specific_intval<false>(std::move(V));
856}
857
858inline specific_intval<false> m_SpecificInt(uint64_t V) {
859 return m_SpecificInt(APInt(64, V));
860}
861
862inline specific_intval<true> m_SpecificIntAllowUndef(APInt V) {
863 return specific_intval<true>(std::move(V));
864}
865
866inline specific_intval<true> m_SpecificIntAllowUndef(uint64_t V) {
867 return m_SpecificIntAllowUndef(APInt(64, V));
868}
869
870/// Match a ConstantInt and bind to its value. This does not match
871/// ConstantInts wider than 64-bits.
872inline bind_const_intval_ty m_ConstantInt(uint64_t &V) { return V; }
873
874/// Match a specified basic block value.
875struct specific_bbval {
876 BasicBlock *Val;
877
878 specific_bbval(BasicBlock *Val) : Val(Val) {}
879
880 template <typename ITy> bool match(ITy *V) {
881 const auto *BB = dyn_cast<BasicBlock>(V);
882 return BB && BB == Val;
883 }
884};
885
886/// Match a specific basic block value.
887inline specific_bbval m_SpecificBB(BasicBlock *BB) {
888 return specific_bbval(BB);
889}
890
891/// A commutative-friendly version of m_Specific().
892inline deferredval_ty<BasicBlock> m_Deferred(BasicBlock *const &BB) {
893 return BB;
894}
895inline deferredval_ty<const BasicBlock>
896m_Deferred(const BasicBlock *const &BB) {
897 return BB;
898}
899
900//===----------------------------------------------------------------------===//
901// Matcher for any binary operator.
902//
903template <typename LHS_t, typename RHS_t, bool Commutable = false>
904struct AnyBinaryOp_match {
905 LHS_t L;
906 RHS_t R;
907
908 // The evaluation order is always stable, regardless of Commutability.
909 // The LHS is always matched first.
910 AnyBinaryOp_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
911
912 template <typename OpTy> bool match(OpTy *V) {
913 if (auto *I = dyn_cast<BinaryOperator>(V))
914 return (L.match(I->getOperand(0)) && R.match(I->getOperand(1))) ||
915 (Commutable && L.match(I->getOperand(1)) &&
916 R.match(I->getOperand(0)));
917 return false;
918 }
919};
920
921template <typename LHS, typename RHS>
922inline AnyBinaryOp_match<LHS, RHS> m_BinOp(const LHS &L, const RHS &R) {
923 return AnyBinaryOp_match<LHS, RHS>(L, R);
924}
925
926//===----------------------------------------------------------------------===//
927// Matcher for any unary operator.
928// TODO fuse unary, binary matcher into n-ary matcher
929//
930template <typename OP_t> struct AnyUnaryOp_match {
931 OP_t X;
932
933 AnyUnaryOp_match(const OP_t &X) : X(X) {}
934
935 template <typename OpTy> bool match(OpTy *V) {
936 if (auto *I = dyn_cast<UnaryOperator>(V))
937 return X.match(I->getOperand(0));
938 return false;
939 }
940};
941
942template <typename OP_t> inline AnyUnaryOp_match<OP_t> m_UnOp(const OP_t &X) {
943 return AnyUnaryOp_match<OP_t>(X);
944}
945
946//===----------------------------------------------------------------------===//
947// Matchers for specific binary operators.
948//
949
950template <typename LHS_t, typename RHS_t, unsigned Opcode,
951 bool Commutable = false>
952struct BinaryOp_match {
953 LHS_t L;
954 RHS_t R;
955
956 // The evaluation order is always stable, regardless of Commutability.
957 // The LHS is always matched first.
958 BinaryOp_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
959
960 template <typename OpTy> inline bool match(unsigned Opc, OpTy *V) {
961 if (V->getValueID() == Value::InstructionVal + Opc) {
962 auto *I = cast<BinaryOperator>(V);
963 return (L.match(I->getOperand(0)) && R.match(I->getOperand(1))) ||
964 (Commutable && L.match(I->getOperand(1)) &&
965 R.match(I->getOperand(0)));
966 }
967 if (auto *CE = dyn_cast<ConstantExpr>(V))
968 return CE->getOpcode() == Opc &&
969 ((L.match(CE->getOperand(0)) && R.match(CE->getOperand(1))) ||
970 (Commutable && L.match(CE->getOperand(1)) &&
971 R.match(CE->getOperand(0))));
972 return false;
973 }
974
975 template <typename OpTy> bool match(OpTy *V) { return match(Opcode, V); }
976};
977
978template <typename LHS, typename RHS>
979inline BinaryOp_match<LHS, RHS, Instruction::Add> m_Add(const LHS &L,
980 const RHS &R) {
981 return BinaryOp_match<LHS, RHS, Instruction::Add>(L, R);
982}
983
984template <typename LHS, typename RHS>
985inline BinaryOp_match<LHS, RHS, Instruction::FAdd> m_FAdd(const LHS &L,
986 const RHS &R) {
987 return BinaryOp_match<LHS, RHS, Instruction::FAdd>(L, R);
988}
989
990template <typename LHS, typename RHS>
991inline BinaryOp_match<LHS, RHS, Instruction::Sub> m_Sub(const LHS &L,
992 const RHS &R) {
993 return BinaryOp_match<LHS, RHS, Instruction::Sub>(L, R);
994}
995
996template <typename LHS, typename RHS>
997inline BinaryOp_match<LHS, RHS, Instruction::FSub> m_FSub(const LHS &L,
998 const RHS &R) {
999 return BinaryOp_match<LHS, RHS, Instruction::FSub>(L, R);
1000}
1001
1002template <typename Op_t> struct FNeg_match {
1003 Op_t X;
1004
1005 FNeg_match(const Op_t &Op) : X(Op) {}
1006 template <typename OpTy> bool match(OpTy *V) {
1007 auto *FPMO = dyn_cast<FPMathOperator>(V);
1008 if (!FPMO)
1009 return false;
1010
1011 if (FPMO->getOpcode() == Instruction::FNeg)
1012 return X.match(FPMO->getOperand(0));
1013
1014 if (FPMO->getOpcode() == Instruction::FSub) {
1015 if (FPMO->hasNoSignedZeros()) {
1016 // With 'nsz', any zero goes.
1017 if (!cstfp_pred_ty<is_any_zero_fp>().match(FPMO->getOperand(0)))
1018 return false;
1019 } else {
1020 // Without 'nsz', we need fsub -0.0, X exactly.
1021 if (!cstfp_pred_ty<is_neg_zero_fp>().match(FPMO->getOperand(0)))
1022 return false;
1023 }
1024
1025 return X.match(FPMO->getOperand(1));
1026 }
1027
1028 return false;
1029 }
1030};
1031
1032/// Match 'fneg X' as 'fsub -0.0, X'.
1033template <typename OpTy> inline FNeg_match<OpTy> m_FNeg(const OpTy &X) {
1034 return FNeg_match<OpTy>(X);
1035}
1036
1037/// Match 'fneg X' as 'fsub +-0.0, X'.
1038template <typename RHS>
1039inline BinaryOp_match<cstfp_pred_ty<is_any_zero_fp>, RHS, Instruction::FSub>
1040m_FNegNSZ(const RHS &X) {
1041 return m_FSub(m_AnyZeroFP(), X);
1042}
1043
1044template <typename LHS, typename RHS>
1045inline BinaryOp_match<LHS, RHS, Instruction::Mul> m_Mul(const LHS &L,
1046 const RHS &R) {
1047 return BinaryOp_match<LHS, RHS, Instruction::Mul>(L, R);
1048}
1049
1050template <typename LHS, typename RHS>
1051inline BinaryOp_match<LHS, RHS, Instruction::FMul> m_FMul(const LHS &L,
1052 const RHS &R) {
1053 return BinaryOp_match<LHS, RHS, Instruction::FMul>(L, R);
1054}
1055
1056template <typename LHS, typename RHS>
1057inline BinaryOp_match<LHS, RHS, Instruction::UDiv> m_UDiv(const LHS &L,
1058 const RHS &R) {
1059 return BinaryOp_match<LHS, RHS, Instruction::UDiv>(L, R);
1060}
1061
1062template <typename LHS, typename RHS>
1063inline BinaryOp_match<LHS, RHS, Instruction::SDiv> m_SDiv(const LHS &L,
1064 const RHS &R) {
1065 return BinaryOp_match<LHS, RHS, Instruction::SDiv>(L, R);
1066}
1067
1068template <typename LHS, typename RHS>
1069inline BinaryOp_match<LHS, RHS, Instruction::FDiv> m_FDiv(const LHS &L,
1070 const RHS &R) {
1071 return BinaryOp_match<LHS, RHS, Instruction::FDiv>(L, R);
1072}
1073
1074template <typename LHS, typename RHS>
1075inline BinaryOp_match<LHS, RHS, Instruction::URem> m_URem(const LHS &L,
1076 const RHS &R) {
1077 return BinaryOp_match<LHS, RHS, Instruction::URem>(L, R);
1078}
1079
1080template <typename LHS, typename RHS>
1081inline BinaryOp_match<LHS, RHS, Instruction::SRem> m_SRem(const LHS &L,
1082 const RHS &R) {
1083 return BinaryOp_match<LHS, RHS, Instruction::SRem>(L, R);
1084}
1085
1086template <typename LHS, typename RHS>
1087inline BinaryOp_match<LHS, RHS, Instruction::FRem> m_FRem(const LHS &L,
1088 const RHS &R) {
1089 return BinaryOp_match<LHS, RHS, Instruction::FRem>(L, R);
1090}
1091
1092template <typename LHS, typename RHS>
1093inline BinaryOp_match<LHS, RHS, Instruction::And> m_And(const LHS &L,
1094 const RHS &R) {
1095 return BinaryOp_match<LHS, RHS, Instruction::And>(L, R);
1096}
1097
1098template <typename LHS, typename RHS>
1099inline BinaryOp_match<LHS, RHS, Instruction::Or> m_Or(const LHS &L,
1100 const RHS &R) {
1101 return BinaryOp_match<LHS, RHS, Instruction::Or>(L, R);
1102}
1103
1104template <typename LHS, typename RHS>
1105inline BinaryOp_match<LHS, RHS, Instruction::Xor> m_Xor(const LHS &L,
1106 const RHS &R) {
1107 return BinaryOp_match<LHS, RHS, Instruction::Xor>(L, R);
1108}
1109
1110template <typename LHS, typename RHS>
1111inline BinaryOp_match<LHS, RHS, Instruction::Shl> m_Shl(const LHS &L,
1112 const RHS &R) {
1113 return BinaryOp_match<LHS, RHS, Instruction::Shl>(L, R);
1114}
1115
1116template <typename LHS, typename RHS>
1117inline BinaryOp_match<LHS, RHS, Instruction::LShr> m_LShr(const LHS &L,
1118 const RHS &R) {
1119 return BinaryOp_match<LHS, RHS, Instruction::LShr>(L, R);
1120}
1121
1122template <typename LHS, typename RHS>
1123inline BinaryOp_match<LHS, RHS, Instruction::AShr> m_AShr(const LHS &L,
1124 const RHS &R) {
1125 return BinaryOp_match<LHS, RHS, Instruction::AShr>(L, R);
1126}
1127
1128template <typename LHS_t, typename RHS_t, unsigned Opcode,
1129 unsigned WrapFlags = 0>
1130struct OverflowingBinaryOp_match {
1131 LHS_t L;
1132 RHS_t R;
1133
1134 OverflowingBinaryOp_match(const LHS_t &LHS, const RHS_t &RHS)
1135 : L(LHS), R(RHS) {}
1136
1137 template <typename OpTy> bool match(OpTy *V) {
1138 if (auto *Op = dyn_cast<OverflowingBinaryOperator>(V)) {
1139 if (Op->getOpcode() != Opcode)
1140 return false;
1141 if ((WrapFlags & OverflowingBinaryOperator::NoUnsignedWrap) &&
1142 !Op->hasNoUnsignedWrap())
1143 return false;
1144 if ((WrapFlags & OverflowingBinaryOperator::NoSignedWrap) &&
1145 !Op->hasNoSignedWrap())
1146 return false;
1147 return L.match(Op->getOperand(0)) && R.match(Op->getOperand(1));
1148 }
1149 return false;
1150 }
1151};
1152
1153template <typename LHS, typename RHS>
1154inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1155 OverflowingBinaryOperator::NoSignedWrap>
1156m_NSWAdd(const LHS &L, const RHS &R) {
1157 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1158 OverflowingBinaryOperator::NoSignedWrap>(L,
1159 R);
1160}
1161template <typename LHS, typename RHS>
1162inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1163 OverflowingBinaryOperator::NoSignedWrap>
1164m_NSWSub(const LHS &L, const RHS &R) {
1165 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1166 OverflowingBinaryOperator::NoSignedWrap>(L,
1167 R);
1168}
1169template <typename LHS, typename RHS>
1170inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1171 OverflowingBinaryOperator::NoSignedWrap>
1172m_NSWMul(const LHS &L, const RHS &R) {
1173 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1174 OverflowingBinaryOperator::NoSignedWrap>(L,
1175 R);
1176}
1177template <typename LHS, typename RHS>
1178inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1179 OverflowingBinaryOperator::NoSignedWrap>
1180m_NSWShl(const LHS &L, const RHS &R) {
1181 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1182 OverflowingBinaryOperator::NoSignedWrap>(L,
1183 R);
1184}
1185
1186template <typename LHS, typename RHS>
1187inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1188 OverflowingBinaryOperator::NoUnsignedWrap>
1189m_NUWAdd(const LHS &L, const RHS &R) {
1190 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Add,
1191 OverflowingBinaryOperator::NoUnsignedWrap>(
1192 L, R);
1193}
1194template <typename LHS, typename RHS>
1195inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1196 OverflowingBinaryOperator::NoUnsignedWrap>
1197m_NUWSub(const LHS &L, const RHS &R) {
1198 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Sub,
1199 OverflowingBinaryOperator::NoUnsignedWrap>(
1200 L, R);
1201}
1202template <typename LHS, typename RHS>
1203inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1204 OverflowingBinaryOperator::NoUnsignedWrap>
1205m_NUWMul(const LHS &L, const RHS &R) {
1206 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Mul,
1207 OverflowingBinaryOperator::NoUnsignedWrap>(
1208 L, R);
1209}
1210template <typename LHS, typename RHS>
1211inline OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1212 OverflowingBinaryOperator::NoUnsignedWrap>
1213m_NUWShl(const LHS &L, const RHS &R) {
1214 return OverflowingBinaryOp_match<LHS, RHS, Instruction::Shl,
1215 OverflowingBinaryOperator::NoUnsignedWrap>(
1216 L, R);
1217}
1218
1219template <typename LHS_t, typename RHS_t, bool Commutable = false>
1220struct SpecificBinaryOp_match
1221 : public BinaryOp_match<LHS_t, RHS_t, 0, Commutable> {
1222 unsigned Opcode;
1223
1224 SpecificBinaryOp_match(unsigned Opcode, const LHS_t &LHS, const RHS_t &RHS)
1225 : BinaryOp_match<LHS_t, RHS_t, 0, Commutable>(LHS, RHS), Opcode(Opcode) {}
1226
1227 template <typename OpTy> bool match(OpTy *V) {
1228 return BinaryOp_match<LHS_t, RHS_t, 0, Commutable>::match(Opcode, V);
1229 }
1230};
1231
1232/// Matches a specific opcode.
1233template <typename LHS, typename RHS>
1234inline SpecificBinaryOp_match<LHS, RHS> m_BinOp(unsigned Opcode, const LHS &L,
1235 const RHS &R) {
1236 return SpecificBinaryOp_match<LHS, RHS>(Opcode, L, R);
1237}
1238
1239//===----------------------------------------------------------------------===//
1240// Class that matches a group of binary opcodes.
1241//
1242template <typename LHS_t, typename RHS_t, typename Predicate>
1243struct BinOpPred_match : Predicate {
1244 LHS_t L;
1245 RHS_t R;
1246
1247 BinOpPred_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
1248
1249 template <typename OpTy> bool match(OpTy *V) {
1250 if (auto *I = dyn_cast<Instruction>(V))
1251 return this->isOpType(I->getOpcode()) && L.match(I->getOperand(0)) &&
1252 R.match(I->getOperand(1));
1253 if (auto *CE = dyn_cast<ConstantExpr>(V))
1254 return this->isOpType(CE->getOpcode()) && L.match(CE->getOperand(0)) &&
1255 R.match(CE->getOperand(1));
1256 return false;
1257 }
1258};
1259
1260struct is_shift_op {
1261 bool isOpType(unsigned Opcode) { return Instruction::isShift(Opcode); }
1262};
1263
1264struct is_right_shift_op {
1265 bool isOpType(unsigned Opcode) {
1266 return Opcode == Instruction::LShr || Opcode == Instruction::AShr;
1267 }
1268};
1269
1270struct is_logical_shift_op {
1271 bool isOpType(unsigned Opcode) {
1272 return Opcode == Instruction::LShr || Opcode == Instruction::Shl;
1273 }
1274};
1275
1276struct is_bitwiselogic_op {
1277 bool isOpType(unsigned Opcode) {
1278 return Instruction::isBitwiseLogicOp(Opcode);
1279 }
1280};
1281
1282struct is_idiv_op {
1283 bool isOpType(unsigned Opcode) {
1284 return Opcode == Instruction::SDiv || Opcode == Instruction::UDiv;
1285 }
1286};
1287
1288struct is_irem_op {
1289 bool isOpType(unsigned Opcode) {
1290 return Opcode == Instruction::SRem || Opcode == Instruction::URem;
1291 }
1292};
1293
1294/// Matches shift operations.
1295template <typename LHS, typename RHS>
1296inline BinOpPred_match<LHS, RHS, is_shift_op> m_Shift(const LHS &L,
1297 const RHS &R) {
1298 return BinOpPred_match<LHS, RHS, is_shift_op>(L, R);
16
Returning without writing to 'L.VR'
1299}
1300
1301/// Matches logical shift operations.
1302template <typename LHS, typename RHS>
1303inline BinOpPred_match<LHS, RHS, is_right_shift_op> m_Shr(const LHS &L,
1304 const RHS &R) {
1305 return BinOpPred_match<LHS, RHS, is_right_shift_op>(L, R);
1306}
1307
1308/// Matches logical shift operations.
1309template <typename LHS, typename RHS>
1310inline BinOpPred_match<LHS, RHS, is_logical_shift_op>
1311m_LogicalShift(const LHS &L, const RHS &R) {
1312 return BinOpPred_match<LHS, RHS, is_logical_shift_op>(L, R);
1313}
1314
1315/// Matches bitwise logic operations.
1316template <typename LHS, typename RHS>
1317inline BinOpPred_match<LHS, RHS, is_bitwiselogic_op>
1318m_BitwiseLogic(const LHS &L, const RHS &R) {
1319 return BinOpPred_match<LHS, RHS, is_bitwiselogic_op>(L, R);
1320}
1321
1322/// Matches integer division operations.
1323template <typename LHS, typename RHS>
1324inline BinOpPred_match<LHS, RHS, is_idiv_op> m_IDiv(const LHS &L,
1325 const RHS &R) {
1326 return BinOpPred_match<LHS, RHS, is_idiv_op>(L, R);
1327}
1328
1329/// Matches integer remainder operations.
1330template <typename LHS, typename RHS>
1331inline BinOpPred_match<LHS, RHS, is_irem_op> m_IRem(const LHS &L,
1332 const RHS &R) {
1333 return BinOpPred_match<LHS, RHS, is_irem_op>(L, R);
1334}
1335
1336//===----------------------------------------------------------------------===//
1337// Class that matches exact binary ops.
1338//
1339template <typename SubPattern_t> struct Exact_match {
1340 SubPattern_t SubPattern;
1341
1342 Exact_match(const SubPattern_t &SP) : SubPattern(SP) {}
1343
1344 template <typename OpTy> bool match(OpTy *V) {
1345 if (auto *PEO = dyn_cast<PossiblyExactOperator>(V))
1346 return PEO->isExact() && SubPattern.match(V);
1347 return false;
1348 }
1349};
1350
1351template <typename T> inline Exact_match<T> m_Exact(const T &SubPattern) {
1352 return SubPattern;
1353}
1354
1355//===----------------------------------------------------------------------===//
1356// Matchers for CmpInst classes
1357//
1358
1359template <typename LHS_t, typename RHS_t, typename Class, typename PredicateTy,
1360 bool Commutable = false>
1361struct CmpClass_match {
1362 PredicateTy &Predicate;
1363 LHS_t L;
1364 RHS_t R;
1365
1366 // The evaluation order is always stable, regardless of Commutability.
1367 // The LHS is always matched first.
1368 CmpClass_match(PredicateTy &Pred, const LHS_t &LHS, const RHS_t &RHS)
1369 : Predicate(Pred), L(LHS), R(RHS) {}
1370
1371 template <typename OpTy> bool match(OpTy *V) {
1372 if (auto *I = dyn_cast<Class>(V)) {
1373 if (L.match(I->getOperand(0)) && R.match(I->getOperand(1))) {
1374 Predicate = I->getPredicate();
1375 return true;
1376 } else if (Commutable && L.match(I->getOperand(1)) &&
1377 R.match(I->getOperand(0))) {
1378 Predicate = I->getSwappedPredicate();
1379 return true;
1380 }
1381 }
1382 return false;
1383 }
1384};
1385
1386template <typename LHS, typename RHS>
1387inline CmpClass_match<LHS, RHS, CmpInst, CmpInst::Predicate>
1388m_Cmp(CmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
1389 return CmpClass_match<LHS, RHS, CmpInst, CmpInst::Predicate>(Pred, L, R);
1390}
1391
1392template <typename LHS, typename RHS>
1393inline CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate>
1394m_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
1395 return CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate>(Pred, L, R);
1396}
1397
1398template <typename LHS, typename RHS>
1399inline CmpClass_match<LHS, RHS, FCmpInst, FCmpInst::Predicate>
1400m_FCmp(FCmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
1401 return CmpClass_match<LHS, RHS, FCmpInst, FCmpInst::Predicate>(Pred, L, R);
1402}
1403
1404//===----------------------------------------------------------------------===//
1405// Matchers for instructions with a given opcode and number of operands.
1406//
1407
1408/// Matches instructions with Opcode and three operands.
1409template <typename T0, unsigned Opcode> struct OneOps_match {
1410 T0 Op1;
1411
1412 OneOps_match(const T0 &Op1) : Op1(Op1) {}
1413
1414 template <typename OpTy> bool match(OpTy *V) {
1415 if (V->getValueID() == Value::InstructionVal + Opcode) {
1416 auto *I = cast<Instruction>(V);
1417 return Op1.match(I->getOperand(0));
1418 }
1419 return false;
1420 }
1421};
1422
1423/// Matches instructions with Opcode and three operands.
1424template <typename T0, typename T1, unsigned Opcode> struct TwoOps_match {
1425 T0 Op1;
1426 T1 Op2;
1427
1428 TwoOps_match(const T0 &Op1, const T1 &Op2) : Op1(Op1), Op2(Op2) {}
1429
1430 template <typename OpTy> bool match(OpTy *V) {
1431 if (V->getValueID() == Value::InstructionVal + Opcode) {
1432 auto *I = cast<Instruction>(V);
1433 return Op1.match(I->getOperand(0)) && Op2.match(I->getOperand(1));
1434 }
1435 return false;
1436 }
1437};
1438
1439/// Matches instructions with Opcode and three operands.
1440template <typename T0, typename T1, typename T2, unsigned Opcode>
1441struct ThreeOps_match {
1442 T0 Op1;
1443 T1 Op2;
1444 T2 Op3;
1445
1446 ThreeOps_match(const T0 &Op1, const T1 &Op2, const T2 &Op3)
1447 : Op1(Op1), Op2(Op2), Op3(Op3) {}
1448
1449 template <typename OpTy> bool match(OpTy *V) {
1450 if (V->getValueID() == Value::InstructionVal + Opcode) {
1451 auto *I = cast<Instruction>(V);
1452 return Op1.match(I->getOperand(0)) && Op2.match(I->getOperand(1)) &&
1453 Op3.match(I->getOperand(2));
1454 }
1455 return false;
1456 }
1457};
1458
1459/// Matches SelectInst.
1460template <typename Cond, typename LHS, typename RHS>
1461inline ThreeOps_match<Cond, LHS, RHS, Instruction::Select>
1462m_Select(const Cond &C, const LHS &L, const RHS &R) {
1463 return ThreeOps_match<Cond, LHS, RHS, Instruction::Select>(C, L, R);
1464}
1465
1466/// This matches a select of two constants, e.g.:
1467/// m_SelectCst<-1, 0>(m_Value(V))
1468template <int64_t L, int64_t R, typename Cond>
1469inline ThreeOps_match<Cond, constantint_match<L>, constantint_match<R>,
1470 Instruction::Select>
1471m_SelectCst(const Cond &C) {
1472 return m_Select(C, m_ConstantInt<L>(), m_ConstantInt<R>());
1473}
1474
1475/// Matches FreezeInst.
1476template <typename OpTy>
1477inline OneOps_match<OpTy, Instruction::Freeze> m_Freeze(const OpTy &Op) {
1478 return OneOps_match<OpTy, Instruction::Freeze>(Op);
1479}
1480
1481/// Matches InsertElementInst.
1482template <typename Val_t, typename Elt_t, typename Idx_t>
1483inline ThreeOps_match<Val_t, Elt_t, Idx_t, Instruction::InsertElement>
1484m_InsertElt(const Val_t &Val, const Elt_t &Elt, const Idx_t &Idx) {
1485 return ThreeOps_match<Val_t, Elt_t, Idx_t, Instruction::InsertElement>(
1486 Val, Elt, Idx);
1487}
1488
1489/// Matches ExtractElementInst.
1490template <typename Val_t, typename Idx_t>
1491inline TwoOps_match<Val_t, Idx_t, Instruction::ExtractElement>
1492m_ExtractElt(const Val_t &Val, const Idx_t &Idx) {
1493 return TwoOps_match<Val_t, Idx_t, Instruction::ExtractElement>(Val, Idx);
1494}
1495
1496/// Matches shuffle.
1497template <typename T0, typename T1, typename T2> struct Shuffle_match {
1498 T0 Op1;
1499 T1 Op2;
1500 T2 Mask;
1501
1502 Shuffle_match(const T0 &Op1, const T1 &Op2, const T2 &Mask)
1503 : Op1(Op1), Op2(Op2), Mask(Mask) {}
1504
1505 template <typename OpTy> bool match(OpTy *V) {
1506 if (auto *I = dyn_cast<ShuffleVectorInst>(V)) {
1507 return Op1.match(I->getOperand(0)) && Op2.match(I->getOperand(1)) &&
1508 Mask.match(I->getShuffleMask());
1509 }
1510 return false;
1511 }
1512};
1513
1514struct m_Mask {
1515 ArrayRef<int> &MaskRef;
1516 m_Mask(ArrayRef<int> &MaskRef) : MaskRef(MaskRef) {}
1517 bool match(ArrayRef<int> Mask) {
1518 MaskRef = Mask;
1519 return true;
1520 }
1521};
1522
1523struct m_ZeroMask {
1524 bool match(ArrayRef<int> Mask) {
1525 return all_of(Mask, [](int Elem) { return Elem == 0 || Elem == -1; });
1526 }
1527};
1528
1529struct m_SpecificMask {
1530 ArrayRef<int> &MaskRef;
1531 m_SpecificMask(ArrayRef<int> &MaskRef) : MaskRef(MaskRef) {}
1532 bool match(ArrayRef<int> Mask) { return MaskRef == Mask; }
1533};
1534
1535struct m_SplatOrUndefMask {
1536 int &SplatIndex;
1537 m_SplatOrUndefMask(int &SplatIndex) : SplatIndex(SplatIndex) {}
1538 bool match(ArrayRef<int> Mask) {
1539 const auto *First = find_if(Mask, [](int Elem) { return Elem != -1; });
1540 if (First == Mask.end())
1541 return false;
1542 SplatIndex = *First;
1543 return all_of(Mask,
1544 [First](int Elem) { return Elem == *First || Elem == -1; });
1545 }
1546};
1547
1548/// Matches ShuffleVectorInst independently of mask value.
1549template <typename V1_t, typename V2_t>
1550inline TwoOps_match<V1_t, V2_t, Instruction::ShuffleVector>
1551m_Shuffle(const V1_t &v1, const V2_t &v2) {
1552 return TwoOps_match<V1_t, V2_t, Instruction::ShuffleVector>(v1, v2);
1553}
1554
1555template <typename V1_t, typename V2_t, typename Mask_t>
1556inline Shuffle_match<V1_t, V2_t, Mask_t>
1557m_Shuffle(const V1_t &v1, const V2_t &v2, const Mask_t &mask) {
1558 return Shuffle_match<V1_t, V2_t, Mask_t>(v1, v2, mask);
1559}
1560
1561/// Matches LoadInst.
1562template <typename OpTy>
1563inline OneOps_match<OpTy, Instruction::Load> m_Load(const OpTy &Op) {
1564 return OneOps_match<OpTy, Instruction::Load>(Op);
1565}
1566
1567/// Matches StoreInst.
1568template <typename ValueOpTy, typename PointerOpTy>
1569inline TwoOps_match<ValueOpTy, PointerOpTy, Instruction::Store>
1570m_Store(const ValueOpTy &ValueOp, const PointerOpTy &PointerOp) {
1571 return TwoOps_match<ValueOpTy, PointerOpTy, Instruction::Store>(ValueOp,
1572 PointerOp);
1573}
1574
1575//===----------------------------------------------------------------------===//
1576// Matchers for CastInst classes
1577//
1578
1579template <typename Op_t, unsigned Opcode> struct CastClass_match {
1580 Op_t Op;
1581
1582 CastClass_match(const Op_t &OpMatch) : Op(OpMatch) {}
1583
1584 template <typename OpTy> bool match(OpTy *V) {
1585 if (auto *O = dyn_cast<Operator>(V))
1586 return O->getOpcode() == Opcode && Op.match(O->getOperand(0));
1587 return false;
1588 }
1589};
1590
1591/// Matches BitCast.
1592template <typename OpTy>
1593inline CastClass_match<OpTy, Instruction::BitCast> m_BitCast(const OpTy &Op) {
1594 return CastClass_match<OpTy, Instruction::BitCast>(Op);
1595}
1596
1597/// Matches PtrToInt.
1598template <typename OpTy>
1599inline CastClass_match<OpTy, Instruction::PtrToInt> m_PtrToInt(const OpTy &Op) {
1600 return CastClass_match<OpTy, Instruction::PtrToInt>(Op);
1601}
1602
1603/// Matches IntToPtr.
1604template <typename OpTy>
1605inline CastClass_match<OpTy, Instruction::IntToPtr> m_IntToPtr(const OpTy &Op) {
1606 return CastClass_match<OpTy, Instruction::IntToPtr>(Op);
1607}
1608
1609/// Matches Trunc.
1610template <typename OpTy>
1611inline CastClass_match<OpTy, Instruction::Trunc> m_Trunc(const OpTy &Op) {
1612 return CastClass_match<OpTy, Instruction::Trunc>(Op);
27
Returning without writing to 'Op.VR'
1613}
1614
1615template <typename OpTy>
1616inline match_combine_or<CastClass_match<OpTy, Instruction::Trunc>, OpTy>
1617m_TruncOrSelf(const OpTy &Op) {
1618 return m_CombineOr(m_Trunc(Op), Op);
1619}
1620
1621/// Matches SExt.
1622template <typename OpTy>
1623inline CastClass_match<OpTy, Instruction::SExt> m_SExt(const OpTy &Op) {
1624 return CastClass_match<OpTy, Instruction::SExt>(Op);
1625}
1626
1627/// Matches ZExt.
1628template <typename OpTy>
1629inline CastClass_match<OpTy, Instruction::ZExt> m_ZExt(const OpTy &Op) {
1630 return CastClass_match<OpTy, Instruction::ZExt>(Op);
1631}
1632
1633template <typename OpTy>
1634inline match_combine_or<CastClass_match<OpTy, Instruction::ZExt>, OpTy>
1635m_ZExtOrSelf(const OpTy &Op) {
1636 return m_CombineOr(m_ZExt(Op), Op);
1637}
1638
1639template <typename OpTy>
1640inline match_combine_or<CastClass_match<OpTy, Instruction::SExt>, OpTy>
1641m_SExtOrSelf(const OpTy &Op) {
1642 return m_CombineOr(m_SExt(Op), Op);
1643}
1644
1645template <typename OpTy>
1646inline match_combine_or<CastClass_match<OpTy, Instruction::ZExt>,
1647 CastClass_match<OpTy, Instruction::SExt>>
1648m_ZExtOrSExt(const OpTy &Op) {
1649 return m_CombineOr(m_ZExt(Op), m_SExt(Op));
1650}
1651
1652template <typename OpTy>
1653inline match_combine_or<
1654 match_combine_or<CastClass_match<OpTy, Instruction::ZExt>,
1655 CastClass_match<OpTy, Instruction::SExt>>,
1656 OpTy>
1657m_ZExtOrSExtOrSelf(const OpTy &Op) {
1658 return m_CombineOr(m_ZExtOrSExt(Op), Op);
1659}
1660
1661template <typename OpTy>
1662inline CastClass_match<OpTy, Instruction::UIToFP> m_UIToFP(const OpTy &Op) {
1663 return CastClass_match<OpTy, Instruction::UIToFP>(Op);
1664}
1665
1666template <typename OpTy>
1667inline CastClass_match<OpTy, Instruction::SIToFP> m_SIToFP(const OpTy &Op) {
1668 return CastClass_match<OpTy, Instruction::SIToFP>(Op);
1669}
1670
1671template <typename OpTy>
1672inline CastClass_match<OpTy, Instruction::FPToUI> m_FPToUI(const OpTy &Op) {
1673 return CastClass_match<OpTy, Instruction::FPToUI>(Op);
1674}
1675
1676template <typename OpTy>
1677inline CastClass_match<OpTy, Instruction::FPToSI> m_FPToSI(const OpTy &Op) {
1678 return CastClass_match<OpTy, Instruction::FPToSI>(Op);
1679}
1680
1681template <typename OpTy>
1682inline CastClass_match<OpTy, Instruction::FPTrunc> m_FPTrunc(const OpTy &Op) {
1683 return CastClass_match<OpTy, Instruction::FPTrunc>(Op);
1684}
1685
1686template <typename OpTy>
1687inline CastClass_match<OpTy, Instruction::FPExt> m_FPExt(const OpTy &Op) {
1688 return CastClass_match<OpTy, Instruction::FPExt>(Op);
1689}
1690
1691//===----------------------------------------------------------------------===//
1692// Matchers for control flow.
1693//
1694
1695struct br_match {
1696 BasicBlock *&Succ;
1697
1698 br_match(BasicBlock *&Succ) : Succ(Succ) {}
1699
1700 template <typename OpTy> bool match(OpTy *V) {
1701 if (auto *BI = dyn_cast<BranchInst>(V))
1702 if (BI->isUnconditional()) {
1703 Succ = BI->getSuccessor(0);
1704 return true;
1705 }
1706 return false;
1707 }
1708};
1709
1710inline br_match m_UnconditionalBr(BasicBlock *&Succ) { return br_match(Succ); }
1711
1712template <typename Cond_t, typename TrueBlock_t, typename FalseBlock_t>
1713struct brc_match {
1714 Cond_t Cond;
1715 TrueBlock_t T;
1716 FalseBlock_t F;
1717
1718 brc_match(const Cond_t &C, const TrueBlock_t &t, const FalseBlock_t &f)
1719 : Cond(C), T(t), F(f) {}
1720
1721 template <typename OpTy> bool match(OpTy *V) {
1722 if (auto *BI = dyn_cast<BranchInst>(V))
1723 if (BI->isConditional() && Cond.match(BI->getCondition()))
1724 return T.match(BI->getSuccessor(0)) && F.match(BI->getSuccessor(1));
1725 return false;
1726 }
1727};
1728
1729template <typename Cond_t>
1730inline brc_match<Cond_t, bind_ty<BasicBlock>, bind_ty<BasicBlock>>
1731m_Br(const Cond_t &C, BasicBlock *&T, BasicBlock *&F) {
1732 return brc_match<Cond_t, bind_ty<BasicBlock>, bind_ty<BasicBlock>>(
1733 C, m_BasicBlock(T), m_BasicBlock(F));
1734}
1735
1736template <typename Cond_t, typename TrueBlock_t, typename FalseBlock_t>
1737inline brc_match<Cond_t, TrueBlock_t, FalseBlock_t>
1738m_Br(const Cond_t &C, const TrueBlock_t &T, const FalseBlock_t &F) {
1739 return brc_match<Cond_t, TrueBlock_t, FalseBlock_t>(C, T, F);
1740}
1741
1742//===----------------------------------------------------------------------===//
1743// Matchers for max/min idioms, eg: "select (sgt x, y), x, y" -> smax(x,y).
1744//
1745
1746template <typename CmpInst_t, typename LHS_t, typename RHS_t, typename Pred_t,
1747 bool Commutable = false>
1748struct MaxMin_match {
1749 using PredType = Pred_t;
1750 LHS_t L;
1751 RHS_t R;
1752
1753 // The evaluation order is always stable, regardless of Commutability.
1754 // The LHS is always matched first.
1755 MaxMin_match(const LHS_t &LHS, const RHS_t &RHS) : L(LHS), R(RHS) {}
1756
1757 template <typename OpTy> bool match(OpTy *V) {
1758 if (auto *II = dyn_cast<IntrinsicInst>(V)) {
1759 Intrinsic::ID IID = II->getIntrinsicID();
1760 if ((IID == Intrinsic::smax && Pred_t::match(ICmpInst::ICMP_SGT)) ||
1761 (IID == Intrinsic::smin && Pred_t::match(ICmpInst::ICMP_SLT)) ||
1762 (IID == Intrinsic::umax && Pred_t::match(ICmpInst::ICMP_UGT)) ||
1763 (IID == Intrinsic::umin && Pred_t::match(ICmpInst::ICMP_ULT))) {
1764 Value *LHS = II->getOperand(0), *RHS = II->getOperand(1);
1765 return (L.match(LHS) && R.match(RHS)) ||
1766 (Commutable && L.match(RHS) && R.match(LHS));
1767 }
1768 }
1769 // Look for "(x pred y) ? x : y" or "(x pred y) ? y : x".
1770 auto *SI = dyn_cast<SelectInst>(V);
1771 if (!SI)
1772 return false;
1773 auto *Cmp = dyn_cast<CmpInst_t>(SI->getCondition());
1774 if (!Cmp)
1775 return false;
1776 // At this point we have a select conditioned on a comparison. Check that
1777 // it is the values returned by the select that are being compared.
1778 auto *TrueVal = SI->getTrueValue();
1779 auto *FalseVal = SI->getFalseValue();
1780 auto *LHS = Cmp->getOperand(0);
1781 auto *RHS = Cmp->getOperand(1);
1782 if ((TrueVal != LHS || FalseVal != RHS) &&
1783 (TrueVal != RHS || FalseVal != LHS))
1784 return false;
1785 typename CmpInst_t::Predicate Pred =
1786 LHS == TrueVal ? Cmp->getPredicate() : Cmp->getInversePredicate();
1787 // Does "(x pred y) ? x : y" represent the desired max/min operation?
1788 if (!Pred_t::match(Pred))
1789 return false;
1790 // It does! Bind the operands.
1791 return (L.match(LHS) && R.match(RHS)) ||
1792 (Commutable && L.match(RHS) && R.match(LHS));
1793 }
1794};
1795
1796/// Helper class for identifying signed max predicates.
1797struct smax_pred_ty {
1798 static bool match(ICmpInst::Predicate Pred) {
1799 return Pred == CmpInst::ICMP_SGT || Pred == CmpInst::ICMP_SGE;
1800 }
1801};
1802
1803/// Helper class for identifying signed min predicates.
1804struct smin_pred_ty {
1805 static bool match(ICmpInst::Predicate Pred) {
1806 return Pred == CmpInst::ICMP_SLT || Pred == CmpInst::ICMP_SLE;
1807 }
1808};
1809
1810/// Helper class for identifying unsigned max predicates.
1811struct umax_pred_ty {
1812 static bool match(ICmpInst::Predicate Pred) {
1813 return Pred == CmpInst::ICMP_UGT || Pred == CmpInst::ICMP_UGE;
1814 }
1815};
1816
1817/// Helper class for identifying unsigned min predicates.
1818struct umin_pred_ty {
1819 static bool match(ICmpInst::Predicate Pred) {
1820 return Pred == CmpInst::ICMP_ULT || Pred == CmpInst::ICMP_ULE;
1821 }
1822};
1823
1824/// Helper class for identifying ordered max predicates.
1825struct ofmax_pred_ty {
1826 static bool match(FCmpInst::Predicate Pred) {
1827 return Pred == CmpInst::FCMP_OGT || Pred == CmpInst::FCMP_OGE;
1828 }
1829};
1830
1831/// Helper class for identifying ordered min predicates.
1832struct ofmin_pred_ty {
1833 static bool match(FCmpInst::Predicate Pred) {
1834 return Pred == CmpInst::FCMP_OLT || Pred == CmpInst::FCMP_OLE;
1835 }
1836};
1837
1838/// Helper class for identifying unordered max predicates.
1839struct ufmax_pred_ty {
1840 static bool match(FCmpInst::Predicate Pred) {
1841 return Pred == CmpInst::FCMP_UGT || Pred == CmpInst::FCMP_UGE;
1842 }
1843};
1844
1845/// Helper class for identifying unordered min predicates.
1846struct ufmin_pred_ty {
1847 static bool match(FCmpInst::Predicate Pred) {
1848 return Pred == CmpInst::FCMP_ULT || Pred == CmpInst::FCMP_ULE;
1849 }
1850};
1851
1852template <typename LHS, typename RHS>
1853inline MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty> m_SMax(const LHS &L,
1854 const RHS &R) {
1855 return MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty>(L, R);
1856}
1857
1858template <typename LHS, typename RHS>
1859inline MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty> m_SMin(const LHS &L,
1860 const RHS &R) {
1861 return MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty>(L, R);
1862}
1863
1864template <typename LHS, typename RHS>
1865inline MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty> m_UMax(const LHS &L,
1866 const RHS &R) {
1867 return MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty>(L, R);
1868}
1869
1870template <typename LHS, typename RHS>
1871inline MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty> m_UMin(const LHS &L,
1872 const RHS &R) {
1873 return MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty>(L, R);
1874}
1875
1876template <typename LHS, typename RHS>
1877inline match_combine_or<
1878 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty>,
1879 MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty>>,
1880 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty>,
1881 MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty>>>
1882m_MaxOrMin(const LHS &L, const RHS &R) {
1883 return m_CombineOr(m_CombineOr(m_SMax(L, R), m_SMin(L, R)),
1884 m_CombineOr(m_UMax(L, R), m_UMin(L, R)));
1885}
1886
1887/// Match an 'ordered' floating point maximum function.
1888/// Floating point has one special value 'NaN'. Therefore, there is no total
1889/// order. However, if we can ignore the 'NaN' value (for example, because of a
1890/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'maximum'
1891/// semantics. In the presence of 'NaN' we have to preserve the original
1892/// select(fcmp(ogt/ge, L, R), L, R) semantics matched by this predicate.
1893///
1894/// max(L, R) iff L and R are not NaN
1895/// m_OrdFMax(L, R) = R iff L or R are NaN
1896template <typename LHS, typename RHS>
1897inline MaxMin_match<FCmpInst, LHS, RHS, ofmax_pred_ty> m_OrdFMax(const LHS &L,
1898 const RHS &R) {
1899 return MaxMin_match<FCmpInst, LHS, RHS, ofmax_pred_ty>(L, R);
1900}
1901
1902/// Match an 'ordered' floating point minimum function.
1903/// Floating point has one special value 'NaN'. Therefore, there is no total
1904/// order. However, if we can ignore the 'NaN' value (for example, because of a
1905/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'minimum'
1906/// semantics. In the presence of 'NaN' we have to preserve the original
1907/// select(fcmp(olt/le, L, R), L, R) semantics matched by this predicate.
1908///
1909/// min(L, R) iff L and R are not NaN
1910/// m_OrdFMin(L, R) = R iff L or R are NaN
1911template <typename LHS, typename RHS>
1912inline MaxMin_match<FCmpInst, LHS, RHS, ofmin_pred_ty> m_OrdFMin(const LHS &L,
1913 const RHS &R) {
1914 return MaxMin_match<FCmpInst, LHS, RHS, ofmin_pred_ty>(L, R);
1915}
1916
1917/// Match an 'unordered' floating point maximum function.
1918/// Floating point has one special value 'NaN'. Therefore, there is no total
1919/// order. However, if we can ignore the 'NaN' value (for example, because of a
1920/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'maximum'
1921/// semantics. In the presence of 'NaN' we have to preserve the original
1922/// select(fcmp(ugt/ge, L, R), L, R) semantics matched by this predicate.
1923///
1924/// max(L, R) iff L and R are not NaN
1925/// m_UnordFMax(L, R) = L iff L or R are NaN
1926template <typename LHS, typename RHS>
1927inline MaxMin_match<FCmpInst, LHS, RHS, ufmax_pred_ty>
1928m_UnordFMax(const LHS &L, const RHS &R) {
1929 return MaxMin_match<FCmpInst, LHS, RHS, ufmax_pred_ty>(L, R);
1930}
1931
1932/// Match an 'unordered' floating point minimum function.
1933/// Floating point has one special value 'NaN'. Therefore, there is no total
1934/// order. However, if we can ignore the 'NaN' value (for example, because of a
1935/// 'no-nans-float-math' flag) a combination of a fcmp and select has 'minimum'
1936/// semantics. In the presence of 'NaN' we have to preserve the original
1937/// select(fcmp(ult/le, L, R), L, R) semantics matched by this predicate.
1938///
1939/// min(L, R) iff L and R are not NaN
1940/// m_UnordFMin(L, R) = L iff L or R are NaN
1941template <typename LHS, typename RHS>
1942inline MaxMin_match<FCmpInst, LHS, RHS, ufmin_pred_ty>
1943m_UnordFMin(const LHS &L, const RHS &R) {
1944 return MaxMin_match<FCmpInst, LHS, RHS, ufmin_pred_ty>(L, R);
1945}
1946
1947//===----------------------------------------------------------------------===//
1948// Matchers for overflow check patterns: e.g. (a + b) u< a, (a ^ -1) <u b
1949// Note that S might be matched to other instructions than AddInst.
1950//
1951
1952template <typename LHS_t, typename RHS_t, typename Sum_t>
1953struct UAddWithOverflow_match {
1954 LHS_t L;
1955 RHS_t R;
1956 Sum_t S;
1957
1958 UAddWithOverflow_match(const LHS_t &L, const RHS_t &R, const Sum_t &S)
1959 : L(L), R(R), S(S) {}
1960
1961 template <typename OpTy> bool match(OpTy *V) {
1962 Value *ICmpLHS, *ICmpRHS;
1963 ICmpInst::Predicate Pred;
1964 if (!m_ICmp(Pred, m_Value(ICmpLHS), m_Value(ICmpRHS)).match(V))
1965 return false;
1966
1967 Value *AddLHS, *AddRHS;
1968 auto AddExpr = m_Add(m_Value(AddLHS), m_Value(AddRHS));
1969
1970 // (a + b) u< a, (a + b) u< b
1971 if (Pred == ICmpInst::ICMP_ULT)
1972 if (AddExpr.match(ICmpLHS) && (ICmpRHS == AddLHS || ICmpRHS == AddRHS))
1973 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpLHS);
1974
1975 // a >u (a + b), b >u (a + b)
1976 if (Pred == ICmpInst::ICMP_UGT)
1977 if (AddExpr.match(ICmpRHS) && (ICmpLHS == AddLHS || ICmpLHS == AddRHS))
1978 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpRHS);
1979
1980 Value *Op1;
1981 auto XorExpr = m_OneUse(m_Xor(m_Value(Op1), m_AllOnes()));
1982 // (a ^ -1) <u b
1983 if (Pred == ICmpInst::ICMP_ULT) {
1984 if (XorExpr.match(ICmpLHS))
1985 return L.match(Op1) && R.match(ICmpRHS) && S.match(ICmpLHS);
1986 }
1987 // b > u (a ^ -1)
1988 if (Pred == ICmpInst::ICMP_UGT) {
1989 if (XorExpr.match(ICmpRHS))
1990 return L.match(Op1) && R.match(ICmpLHS) && S.match(ICmpRHS);
1991 }
1992
1993 // Match special-case for increment-by-1.
1994 if (Pred == ICmpInst::ICMP_EQ) {
1995 // (a + 1) == 0
1996 // (1 + a) == 0
1997 if (AddExpr.match(ICmpLHS) && m_ZeroInt().match(ICmpRHS) &&
1998 (m_One().match(AddLHS) || m_One().match(AddRHS)))
1999 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpLHS);
2000 // 0 == (a + 1)
2001 // 0 == (1 + a)
2002 if (m_ZeroInt().match(ICmpLHS) && AddExpr.match(ICmpRHS) &&
2003 (m_One().match(AddLHS) || m_One().match(AddRHS)))
2004 return L.match(AddLHS) && R.match(AddRHS) && S.match(ICmpRHS);
2005 }
2006
2007 return false;
2008 }
2009};
2010
2011/// Match an icmp instruction checking for unsigned overflow on addition.
2012///
2013/// S is matched to the addition whose result is being checked for overflow, and
2014/// L and R are matched to the LHS and RHS of S.
2015template <typename LHS_t, typename RHS_t, typename Sum_t>
2016UAddWithOverflow_match<LHS_t, RHS_t, Sum_t>
2017m_UAddWithOverflow(const LHS_t &L, const RHS_t &R, const Sum_t &S) {
2018 return UAddWithOverflow_match<LHS_t, RHS_t, Sum_t>(L, R, S);
2019}
2020
2021template <typename Opnd_t> struct Argument_match {
2022 unsigned OpI;
2023 Opnd_t Val;
2024
2025 Argument_match(unsigned OpIdx, const Opnd_t &V) : OpI(OpIdx), Val(V) {}
2026
2027 template <typename OpTy> bool match(OpTy *V) {
2028 // FIXME: Should likely be switched to use `CallBase`.
2029 if (const auto *CI = dyn_cast<CallInst>(V))
2030 return Val.match(CI->getArgOperand(OpI));
2031 return false;
2032 }
2033};
2034
2035/// Match an argument.
2036template <unsigned OpI, typename Opnd_t>
2037inline Argument_match<Opnd_t> m_Argument(const Opnd_t &Op) {
2038 return Argument_match<Opnd_t>(OpI, Op);
2039}
2040
2041/// Intrinsic matchers.
2042struct IntrinsicID_match {
2043 unsigned ID;
2044
2045 IntrinsicID_match(Intrinsic::ID IntrID) : ID(IntrID) {}
2046
2047 template <typename OpTy> bool match(OpTy *V) {
2048 if (const auto *CI = dyn_cast<CallInst>(V))
2049 if (const auto *F = CI->getCalledFunction())
2050 return F->getIntrinsicID() == ID;
2051 return false;
2052 }
2053};
2054
2055/// Intrinsic matches are combinations of ID matchers, and argument
2056/// matchers. Higher arity matcher are defined recursively in terms of and-ing
2057/// them with lower arity matchers. Here's some convenient typedefs for up to
2058/// several arguments, and more can be added as needed
2059template <typename T0 = void, typename T1 = void, typename T2 = void,
2060 typename T3 = void, typename T4 = void, typename T5 = void,
2061 typename T6 = void, typename T7 = void, typename T8 = void,
2062 typename T9 = void, typename T10 = void>
2063struct m_Intrinsic_Ty;
2064template <typename T0> struct m_Intrinsic_Ty<T0> {
2065 using Ty = match_combine_and<IntrinsicID_match, Argument_match<T0>>;
2066};
2067template <typename T0, typename T1> struct m_Intrinsic_Ty<T0, T1> {
2068 using Ty =
2069 match_combine_and<typename m_Intrinsic_Ty<T0>::Ty, Argument_match<T1>>;
2070};
2071template <typename T0, typename T1, typename T2>
2072struct m_Intrinsic_Ty<T0, T1, T2> {
2073 using Ty = match_combine_and<typename m_Intrinsic_Ty<T0, T1>::Ty,
2074 Argument_match<T2>>;
2075};
2076template <typename T0, typename T1, typename T2, typename T3>
2077struct m_Intrinsic_Ty<T0, T1, T2, T3> {
2078 using Ty = match_combine_and<typename m_Intrinsic_Ty<T0, T1, T2>::Ty,
2079 Argument_match<T3>>;
2080};
2081
2082template <typename T0, typename T1, typename T2, typename T3, typename T4>
2083struct m_Intrinsic_Ty<T0, T1, T2, T3, T4> {
2084 using Ty = match_combine_and<typename m_Intrinsic_Ty<T0, T1, T2, T3>::Ty,
2085 Argument_match<T4>>;
2086};
2087
2088template <typename T0, typename T1, typename T2, typename T3, typename T4,
2089 typename T5>
2090struct m_Intrinsic_Ty<T0, T1, T2, T3, T4, T5> {
2091 using Ty = match_combine_and<typename m_Intrinsic_Ty<T0, T1, T2, T3, T4>::Ty,
2092 Argument_match<T5>>;
2093};
2094
2095/// Match intrinsic calls like this:
2096/// m_Intrinsic<Intrinsic::fabs>(m_Value(X))
2097template <Intrinsic::ID IntrID> inline IntrinsicID_match m_Intrinsic() {
2098 return IntrinsicID_match(IntrID);
2099}
2100
2101/// Matches MaskedLoad Intrinsic.
2102template <typename Opnd0, typename Opnd1, typename Opnd2, typename Opnd3>
2103inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2, Opnd3>::Ty
2104m_MaskedLoad(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2,
2105 const Opnd3 &Op3) {
2106 return m_Intrinsic<Intrinsic::masked_load>(Op0, Op1, Op2, Op3);
2107}
2108
2109/// Matches MaskedGather Intrinsic.
2110template <typename Opnd0, typename Opnd1, typename Opnd2, typename Opnd3>
2111inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2, Opnd3>::Ty
2112m_MaskedGather(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2,
2113 const Opnd3 &Op3) {
2114 return m_Intrinsic<Intrinsic::masked_gather>(Op0, Op1, Op2, Op3);
2115}
2116
2117template <Intrinsic::ID IntrID, typename T0>
2118inline typename m_Intrinsic_Ty<T0>::Ty m_Intrinsic(const T0 &Op0) {
2119 return m_CombineAnd(m_Intrinsic<IntrID>(), m_Argument<0>(Op0));
2120}
2121
2122template <Intrinsic::ID IntrID, typename T0, typename T1>
2123inline typename m_Intrinsic_Ty<T0, T1>::Ty m_Intrinsic(const T0 &Op0,
2124 const T1 &Op1) {
2125 return m_CombineAnd(m_Intrinsic<IntrID>(Op0), m_Argument<1>(Op1));
2126}
2127
2128template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2>
2129inline typename m_Intrinsic_Ty<T0, T1, T2>::Ty
2130m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2) {
2131 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1), m_Argument<2>(Op2));
2132}
2133
2134template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2,
2135 typename T3>
2136inline typename m_Intrinsic_Ty<T0, T1, T2, T3>::Ty
2137m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2, const T3 &Op3) {
2138 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1, Op2), m_Argument<3>(Op3));
2139}
2140
2141template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2,
2142 typename T3, typename T4>
2143inline typename m_Intrinsic_Ty<T0, T1, T2, T3, T4>::Ty
2144m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2, const T3 &Op3,
2145 const T4 &Op4) {
2146 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1, Op2, Op3),
2147 m_Argument<4>(Op4));
2148}
2149
2150template <Intrinsic::ID IntrID, typename T0, typename T1, typename T2,
2151 typename T3, typename T4, typename T5>
2152inline typename m_Intrinsic_Ty<T0, T1, T2, T3, T4, T5>::Ty
2153m_Intrinsic(const T0 &Op0, const T1 &Op1, const T2 &Op2, const T3 &Op3,
2154 const T4 &Op4, const T5 &Op5) {
2155 return m_CombineAnd(m_Intrinsic<IntrID>(Op0, Op1, Op2, Op3, Op4),
2156 m_Argument<5>(Op5));
2157}
2158
2159// Helper intrinsic matching specializations.
2160template <typename Opnd0>
2161inline typename m_Intrinsic_Ty<Opnd0>::Ty m_BitReverse(const Opnd0 &Op0) {
2162 return m_Intrinsic<Intrinsic::bitreverse>(Op0);
2163}
2164
2165template <typename Opnd0>
2166inline typename m_Intrinsic_Ty<Opnd0>::Ty m_BSwap(const Opnd0 &Op0) {
2167 return m_Intrinsic<Intrinsic::bswap>(Op0);
2168}
2169
2170template <typename Opnd0>
2171inline typename m_Intrinsic_Ty<Opnd0>::Ty m_FAbs(const Opnd0 &Op0) {
2172 return m_Intrinsic<Intrinsic::fabs>(Op0);
2173}
2174
2175template <typename Opnd0>
2176inline typename m_Intrinsic_Ty<Opnd0>::Ty m_FCanonicalize(const Opnd0 &Op0) {
2177 return m_Intrinsic<Intrinsic::canonicalize>(Op0);
2178}
2179
2180template <typename Opnd0, typename Opnd1>
2181inline typename m_Intrinsic_Ty<Opnd0, Opnd1>::Ty m_FMin(const Opnd0 &Op0,
2182 const Opnd1 &Op1) {
2183 return m_Intrinsic<Intrinsic::minnum>(Op0, Op1);
2184}
2185
2186template <typename Opnd0, typename Opnd1>
2187inline typename m_Intrinsic_Ty<Opnd0, Opnd1>::Ty m_FMax(const Opnd0 &Op0,
2188 const Opnd1 &Op1) {
2189 return m_Intrinsic<Intrinsic::maxnum>(Op0, Op1);
2190}
2191
2192template <typename Opnd0, typename Opnd1, typename Opnd2>
2193inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2>::Ty
2194m_FShl(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2) {
2195 return m_Intrinsic<Intrinsic::fshl>(Op0, Op1, Op2);
2196}
2197
2198template <typename Opnd0, typename Opnd1, typename Opnd2>
2199inline typename m_Intrinsic_Ty<Opnd0, Opnd1, Opnd2>::Ty
2200m_FShr(const Opnd0 &Op0, const Opnd1 &Op1, const Opnd2 &Op2) {
2201 return m_Intrinsic<Intrinsic::fshr>(Op0, Op1, Op2);
2202}
2203
2204template <typename Opnd0>
2205inline typename m_Intrinsic_Ty<Opnd0>::Ty m_Sqrt(const Opnd0 &Op0) {
2206 return m_Intrinsic<Intrinsic::sqrt>(Op0);
2207}
2208
2209template <typename Opnd0, typename Opnd1>
2210inline typename m_Intrinsic_Ty<Opnd0, Opnd1>::Ty m_CopySign(const Opnd0 &Op0,
2211 const Opnd1 &Op1) {
2212 return m_Intrinsic<Intrinsic::copysign>(Op0, Op1);
2213}
2214
2215template <typename Opnd0>
2216inline typename m_Intrinsic_Ty<Opnd0>::Ty m_VecReverse(const Opnd0 &Op0) {
2217 return m_Intrinsic<Intrinsic::experimental_vector_reverse>(Op0);
2218}
2219
2220//===----------------------------------------------------------------------===//
2221// Matchers for two-operands operators with the operators in either order
2222//
2223
2224/// Matches a BinaryOperator with LHS and RHS in either order.
2225template <typename LHS, typename RHS>
2226inline AnyBinaryOp_match<LHS, RHS, true> m_c_BinOp(const LHS &L, const RHS &R) {
2227 return AnyBinaryOp_match<LHS, RHS, true>(L, R);
2228}
2229
2230/// Matches an ICmp with a predicate over LHS and RHS in either order.
2231/// Swaps the predicate if operands are commuted.
2232template <typename LHS, typename RHS>
2233inline CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate, true>
2234m_c_ICmp(ICmpInst::Predicate &Pred, const LHS &L, const RHS &R) {
2235 return CmpClass_match<LHS, RHS, ICmpInst, ICmpInst::Predicate, true>(Pred, L,
2236 R);
2237}
2238
2239/// Matches a specific opcode with LHS and RHS in either order.
2240template <typename LHS, typename RHS>
2241inline SpecificBinaryOp_match<LHS, RHS, true>
2242m_c_BinOp(unsigned Opcode, const LHS &L, const RHS &R) {
2243 return SpecificBinaryOp_match<LHS, RHS, true>(Opcode, L, R);
2244}
2245
2246/// Matches a Add with LHS and RHS in either order.
2247template <typename LHS, typename RHS>
2248inline BinaryOp_match<LHS, RHS, Instruction::Add, true> m_c_Add(const LHS &L,
2249 const RHS &R) {
2250 return BinaryOp_match<LHS, RHS, Instruction::Add, true>(L, R);
2251}
2252
2253/// Matches a Mul with LHS and RHS in either order.
2254template <typename LHS, typename RHS>
2255inline BinaryOp_match<LHS, RHS, Instruction::Mul, true> m_c_Mul(const LHS &L,
2256 const RHS &R) {
2257 return BinaryOp_match<LHS, RHS, Instruction::Mul, true>(L, R);
2258}
2259
2260/// Matches an And with LHS and RHS in either order.
2261template <typename LHS, typename RHS>
2262inline BinaryOp_match<LHS, RHS, Instruction::And, true> m_c_And(const LHS &L,
2263 const RHS &R) {
2264 return BinaryOp_match<LHS, RHS, Instruction::And, true>(L, R);
2265}
2266
2267/// Matches an Or with LHS and RHS in either order.
2268template <typename LHS, typename RHS>
2269inline BinaryOp_match<LHS, RHS, Instruction::Or, true> m_c_Or(const LHS &L,
2270 const RHS &R) {
2271 return BinaryOp_match<LHS, RHS, Instruction::Or, true>(L, R);
2272}
2273
2274/// Matches an Xor with LHS and RHS in either order.
2275template <typename LHS, typename RHS>
2276inline BinaryOp_match<LHS, RHS, Instruction::Xor, true> m_c_Xor(const LHS &L,
2277 const RHS &R) {
2278 return BinaryOp_match<LHS, RHS, Instruction::Xor, true>(L, R);
2279}
2280
2281/// Matches a 'Neg' as 'sub 0, V'.
2282template <typename ValTy>
2283inline BinaryOp_match<cst_pred_ty<is_zero_int>, ValTy, Instruction::Sub>
2284m_Neg(const ValTy &V) {
2285 return m_Sub(m_ZeroInt(), V);
2286}
2287
2288/// Matches a 'Neg' as 'sub nsw 0, V'.
2289template <typename ValTy>
2290inline OverflowingBinaryOp_match<cst_pred_ty<is_zero_int>, ValTy,
2291 Instruction::Sub,
2292 OverflowingBinaryOperator::NoSignedWrap>
2293m_NSWNeg(const ValTy &V) {
2294 return m_NSWSub(m_ZeroInt(), V);
2295}
2296
2297/// Matches a 'Not' as 'xor V, -1' or 'xor -1, V'.
2298/// NOTE: we first match the 'Not' (by matching '-1'),
2299/// and only then match the inner matcher!
2300template <typename ValTy>
2301inline BinaryOp_match<cst_pred_ty<is_all_ones>, ValTy, Instruction::Xor, true>
2302m_Not(const ValTy &V) {
2303 return m_c_Xor(m_AllOnes(), V);
2304}
2305
2306template <typename ValTy> struct NotForbidUndef_match {
2307 ValTy Val;
2308 NotForbidUndef_match(const ValTy &V) : Val(V) {}
2309
2310 template <typename OpTy> bool match(OpTy *V) {
2311 // We do not use m_c_Xor because that could match an arbitrary APInt that is
2312 // not -1 as C and then fail to match the other operand if it is -1.
2313 // This code should still work even when both operands are constants.
2314 Value *X;
2315 const APInt *C;
2316 if (m_Xor(m_Value(X), m_APIntForbidUndef(C)).match(V) && C->isAllOnes())
2317 return Val.match(X);
2318 if (m_Xor(m_APIntForbidUndef(C), m_Value(X)).match(V) && C->isAllOnes())
2319 return Val.match(X);
2320 return false;
2321 }
2322};
2323
2324/// Matches a bitwise 'not' as 'xor V, -1' or 'xor -1, V'. For vectors, the
2325/// constant value must be composed of only -1 scalar elements.
2326template <typename ValTy>
2327inline NotForbidUndef_match<ValTy> m_NotForbidUndef(const ValTy &V) {
2328 return NotForbidUndef_match<ValTy>(V);
2329}
2330
2331/// Matches an SMin with LHS and RHS in either order.
2332template <typename LHS, typename RHS>
2333inline MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty, true>
2334m_c_SMin(const LHS &L, const RHS &R) {
2335 return MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty, true>(L, R);
2336}
2337/// Matches an SMax with LHS and RHS in either order.
2338template <typename LHS, typename RHS>
2339inline MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty, true>
2340m_c_SMax(const LHS &L, const RHS &R) {
2341 return MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty, true>(L, R);
2342}
2343/// Matches a UMin with LHS and RHS in either order.
2344template <typename LHS, typename RHS>
2345inline MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty, true>
2346m_c_UMin(const LHS &L, const RHS &R) {
2347 return MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty, true>(L, R);
2348}
2349/// Matches a UMax with LHS and RHS in either order.
2350template <typename LHS, typename RHS>
2351inline MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty, true>
2352m_c_UMax(const LHS &L, const RHS &R) {
2353 return MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty, true>(L, R);
2354}
2355
2356template <typename LHS, typename RHS>
2357inline match_combine_or<
2358 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, smax_pred_ty, true>,
2359 MaxMin_match<ICmpInst, LHS, RHS, smin_pred_ty, true>>,
2360 match_combine_or<MaxMin_match<ICmpInst, LHS, RHS, umax_pred_ty, true>,
2361 MaxMin_match<ICmpInst, LHS, RHS, umin_pred_ty, true>>>
2362m_c_MaxOrMin(const LHS &L, const RHS &R) {
2363 return m_CombineOr(m_CombineOr(m_c_SMax(L, R), m_c_SMin(L, R)),
2364 m_CombineOr(m_c_UMax(L, R), m_c_UMin(L, R)));
2365}
2366
2367template <Intrinsic::ID IntrID, typename T0, typename T1>
2368inline match_combine_or<typename m_Intrinsic_Ty<T0, T1>::Ty,
2369 typename m_Intrinsic_Ty<T1, T0>::Ty>
2370m_c_Intrinsic(const T0 &Op0, const T1 &Op1) {
2371 return m_CombineOr(m_Intrinsic<IntrID>(Op0, Op1),
2372 m_Intrinsic<IntrID>(Op1, Op0));
2373}
2374
2375/// Matches FAdd with LHS and RHS in either order.
2376template <typename LHS, typename RHS>
2377inline BinaryOp_match<LHS, RHS, Instruction::FAdd, true>
2378m_c_FAdd(const LHS &L, const RHS &R) {
2379 return BinaryOp_match<LHS, RHS, Instruction::FAdd, true>(L, R);
2380}
2381
2382/// Matches FMul with LHS and RHS in either order.
2383template <typename LHS, typename RHS>
2384inline BinaryOp_match<LHS, RHS, Instruction::FMul, true>
2385m_c_FMul(const LHS &L, const RHS &R) {
2386 return BinaryOp_match<LHS, RHS, Instruction::FMul, true>(L, R);
2387}
2388
2389template <typename Opnd_t> struct Signum_match {
2390 Opnd_t Val;
2391 Signum_match(const Opnd_t &V) : Val(V) {}
2392
2393 template <typename OpTy> bool match(OpTy *V) {
2394 unsigned TypeSize = V->getType()->getScalarSizeInBits();
2395 if (TypeSize == 0)
2396 return false;
2397
2398 unsigned ShiftWidth = TypeSize - 1;
2399 Value *OpL = nullptr, *OpR = nullptr;
2400
2401 // This is the representation of signum we match:
2402 //
2403 // signum(x) == (x >> 63) | (-x >>u 63)
2404 //
2405 // An i1 value is its own signum, so it's correct to match
2406 //
2407 // signum(x) == (x >> 0) | (-x >>u 0)
2408 //
2409 // for i1 values.
2410
2411 auto LHS = m_AShr(m_Value(OpL), m_SpecificInt(ShiftWidth));
2412 auto RHS = m_LShr(m_Neg(m_Value(OpR)), m_SpecificInt(ShiftWidth));
2413 auto Signum = m_Or(LHS, RHS);
2414
2415 return Signum.match(V) && OpL == OpR && Val.match(OpL);
2416 }
2417};
2418
2419/// Matches a signum pattern.
2420///
2421/// signum(x) =
2422/// x > 0 -> 1
2423/// x == 0 -> 0
2424/// x < 0 -> -1
2425template <typename Val_t> inline Signum_match<Val_t> m_Signum(const Val_t &V) {
2426 return Signum_match<Val_t>(V);
2427}
2428
2429template <int Ind, typename Opnd_t> struct ExtractValue_match {
2430 Opnd_t Val;
2431 ExtractValue_match(const Opnd_t &V) : Val(V) {}
2432
2433 template <typename OpTy> bool match(OpTy *V) {
2434 if (auto *I = dyn_cast<ExtractValueInst>(V)) {
2435 // If Ind is -1, don't inspect indices
2436 if (Ind != -1 &&
2437 !(I->getNumIndices() == 1 && I->getIndices()[0] == (unsigned)Ind))
2438 return false;
2439 return Val.match(I->getAggregateOperand());
2440 }
2441 return false;
2442 }
2443};
2444
2445/// Match a single index ExtractValue instruction.
2446/// For example m_ExtractValue<1>(...)
2447template <int Ind, typename Val_t>
2448inline ExtractValue_match<Ind, Val_t> m_ExtractValue(const Val_t &V) {
2449 return ExtractValue_match<Ind, Val_t>(V);
2450}
2451
2452/// Match an ExtractValue instruction with any index.
2453/// For example m_ExtractValue(...)
2454template <typename Val_t>
2455inline ExtractValue_match<-1, Val_t> m_ExtractValue(const Val_t &V) {
2456 return ExtractValue_match<-1, Val_t>(V);
2457}
2458
2459/// Matcher for a single index InsertValue instruction.
2460template <int Ind, typename T0, typename T1> struct InsertValue_match {
2461 T0 Op0;
2462 T1 Op1;
2463
2464 InsertValue_match(const T0 &Op0, const T1 &Op1) : Op0(Op0), Op1(Op1) {}
2465
2466 template <typename OpTy> bool match(OpTy *V) {
2467 if (auto *I = dyn_cast<InsertValueInst>(V)) {
2468 return Op0.match(I->getOperand(0)) && Op1.match(I->getOperand(1)) &&
2469 I->getNumIndices() == 1 && Ind == I->getIndices()[0];
2470 }
2471 return false;
2472 }
2473};
2474
2475/// Matches a single index InsertValue instruction.
2476template <int Ind, typename Val_t, typename Elt_t>
2477inline InsertValue_match<Ind, Val_t, Elt_t> m_InsertValue(const Val_t &Val,
2478 const Elt_t &Elt) {
2479 return InsertValue_match<Ind, Val_t, Elt_t>(Val, Elt);
2480}
2481
2482/// Matches patterns for `vscale`. This can either be a call to `llvm.vscale` or
2483/// the constant expression
2484/// `ptrtoint(gep <vscale x 1 x i8>, <vscale x 1 x i8>* null, i32 1>`
2485/// under the right conditions determined by DataLayout.
2486struct VScaleVal_match {
2487 template <typename ITy> bool match(ITy *V) {
2488 if (m_Intrinsic<Intrinsic::vscale>().match(V))
2489 return true;
2490
2491 Value *Ptr;
2492 if (m_PtrToInt(m_Value(Ptr)).match(V)) {
2493 if (auto *GEP = dyn_cast<GEPOperator>(Ptr)) {
2494 auto *DerefTy =
2495 dyn_cast<ScalableVectorType>(GEP->getSourceElementType());
2496 if (GEP->getNumIndices() == 1 && DerefTy &&
2497 DerefTy->getElementType()->isIntegerTy(8) &&
2498 m_Zero().match(GEP->getPointerOperand()) &&
2499 m_SpecificInt(1).match(GEP->idx_begin()->get()))
2500 return true;
2501 }
2502 }
2503
2504 return false;
2505 }
2506};
2507
2508inline VScaleVal_match m_VScale() {
2509 return VScaleVal_match();
2510}
2511
2512template <typename LHS, typename RHS, unsigned Opcode, bool Commutable = false>
2513struct LogicalOp_match {
2514 LHS L;
2515 RHS R;
2516
2517 LogicalOp_match(const LHS &L, const RHS &R) : L(L), R(R) {}
2518
2519 template <typename T> bool match(T *V) {
2520 auto *I = dyn_cast<Instruction>(V);
2521 if (!I || !I->getType()->isIntOrIntVectorTy(1))
2522 return false;
2523
2524 if (I->getOpcode() == Opcode) {
2525 auto *Op0 = I->getOperand(0);
2526 auto *Op1 = I->getOperand(1);
2527 return (L.match(Op0) && R.match(Op1)) ||
2528 (Commutable && L.match(Op1) && R.match(Op0));
2529 }
2530
2531 if (auto *Select = dyn_cast<SelectInst>(I)) {
2532 auto *Cond = Select->getCondition();
2533 auto *TVal = Select->getTrueValue();
2534 auto *FVal = Select->getFalseValue();
2535
2536 // Don't match a scalar select of bool vectors.
2537 // Transforms expect a single type for operands if this matches.
2538 if (Cond->getType() != Select->getType())
2539 return false;
2540
2541 if (Opcode == Instruction::And) {
2542 auto *C = dyn_cast<Constant>(FVal);
2543 if (C && C->isNullValue())
2544 return (L.match(Cond) && R.match(TVal)) ||
2545 (Commutable && L.match(TVal) && R.match(Cond));
2546 } else {
2547 assert(Opcode == Instruction::Or)(static_cast <bool> (Opcode == Instruction::Or) ? void (
0) : __assert_fail ("Opcode == Instruction::Or", "llvm/include/llvm/IR/PatternMatch.h"
, 2547, __extension__ __PRETTY_FUNCTION__))
;
2548 auto *C = dyn_cast<Constant>(TVal);
2549 if (C && C->isOneValue())
2550 return (L.match(Cond) && R.match(FVal)) ||
2551 (Commutable && L.match(FVal) && R.match(Cond));
2552 }
2553 }
2554
2555 return false;
2556 }
2557};
2558
2559/// Matches L && R either in the form of L & R or L ? R : false.
2560/// Note that the latter form is poison-blocking.
2561template <typename LHS, typename RHS>
2562inline LogicalOp_match<LHS, RHS, Instruction::And> m_LogicalAnd(const LHS &L,
2563 const RHS &R) {
2564 return LogicalOp_match<LHS, RHS, Instruction::And>(L, R);
2565}
2566
2567/// Matches L && R where L and R are arbitrary values.
2568inline auto m_LogicalAnd() { return m_LogicalAnd(m_Value(), m_Value()); }
2569
2570/// Matches L && R with LHS and RHS in either order.
2571template <typename LHS, typename RHS>
2572inline LogicalOp_match<LHS, RHS, Instruction::And, true>
2573m_c_LogicalAnd(const LHS &L, const RHS &R) {
2574 return LogicalOp_match<LHS, RHS, Instruction::And, true>(L, R);
2575}
2576
2577/// Matches L || R either in the form of L | R or L ? true : R.
2578/// Note that the latter form is poison-blocking.
2579template <typename LHS, typename RHS>
2580inline LogicalOp_match<LHS, RHS, Instruction::Or> m_LogicalOr(const LHS &L,
2581 const RHS &R) {
2582 return LogicalOp_match<LHS, RHS, Instruction::Or>(L, R);
2583}
2584
2585/// Matches L || R where L and R are arbitrary values.
2586inline auto m_LogicalOr() { return m_LogicalOr(m_Value(), m_Value()); }
2587
2588/// Matches L || R with LHS and RHS in either order.
2589template <typename LHS, typename RHS>
2590inline LogicalOp_match<LHS, RHS, Instruction::Or, true>
2591m_c_LogicalOr(const LHS &L, const RHS &R) {
2592 return LogicalOp_match<LHS, RHS, Instruction::Or, true>(L, R);
2593}
2594
2595/// Matches either L && R or L || R,
2596/// either one being in the either binary or logical form.
2597/// Note that the latter form is poison-blocking.
2598template <typename LHS, typename RHS, bool Commutable = false>
2599inline auto m_LogicalOp(const LHS &L, const RHS &R) {
2600 return m_CombineOr(
2601 LogicalOp_match<LHS, RHS, Instruction::And, Commutable>(L, R),
2602 LogicalOp_match<LHS, RHS, Instruction::Or, Commutable>(L, R));
2603}
2604
2605/// Matches either L && R or L || R where L and R are arbitrary values.
2606inline auto m_LogicalOp() { return m_LogicalOp(m_Value(), m_Value()); }
2607
2608/// Matches either L && R or L || R with LHS and RHS in either order.
2609template <typename LHS, typename RHS>
2610inline auto m_c_LogicalOp(const LHS &L, const RHS &R) {
2611 return m_LogicalOp<LHS, RHS, /*Commutable=*/true>(L, R);
2612}
2613
2614} // end namespace PatternMatch
2615} // end namespace llvm
2616
2617#endif // LLVM_IR_PATTERNMATCH_H