1 //===- InstructionSimplify.cpp - Fold instruction operands ----------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements routines for folding instructions into simpler forms
10 // that do not require creating new instructions. This does constant folding
11 // ("add i32 1, 1" -> "2") but can also handle non-constant operands, either
12 // returning a constant ("and i32 %x, 0" -> "0") or an already existing value
13 // ("and i32 %x, %x" -> "%x"). All operands are assumed to have already been
14 // simplified: This is usually true and assuming it simplifies the logic (if
15 // they have not been simplified then results are correct but maybe suboptimal).
17 //===----------------------------------------------------------------------===//
19 #include "llvm/Analysis/InstructionSimplify.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/SetVector.h"
23 #include "llvm/ADT/Statistic.h"
24 #include "llvm/Analysis/AliasAnalysis.h"
25 #include "llvm/Analysis/AssumptionCache.h"
26 #include "llvm/Analysis/CaptureTracking.h"
27 #include "llvm/Analysis/CmpInstAnalysis.h"
28 #include "llvm/Analysis/ConstantFolding.h"
29 #include "llvm/Analysis/InstSimplifyFolder.h"
30 #include "llvm/Analysis/Loads.h"
31 #include "llvm/Analysis/LoopAnalysisManager.h"
32 #include "llvm/Analysis/MemoryBuiltins.h"
33 #include "llvm/Analysis/OverflowInstAnalysis.h"
34 #include "llvm/Analysis/TargetLibraryInfo.h"
35 #include "llvm/Analysis/ValueTracking.h"
36 #include "llvm/Analysis/VectorUtils.h"
37 #include "llvm/IR/ConstantRange.h"
38 #include "llvm/IR/DataLayout.h"
39 #include "llvm/IR/Dominators.h"
40 #include "llvm/IR/InstrTypes.h"
41 #include "llvm/IR/Instructions.h"
42 #include "llvm/IR/Operator.h"
43 #include "llvm/IR/PatternMatch.h"
44 #include "llvm/IR/Statepoint.h"
45 #include "llvm/Support/KnownBits.h"
49 using namespace llvm::PatternMatch
;
51 #define DEBUG_TYPE "instsimplify"
53 enum { RecursionLimit
= 3 };
55 STATISTIC(NumExpand
, "Number of expansions");
56 STATISTIC(NumReassoc
, "Number of reassociations");
58 static Value
*simplifyAndInst(Value
*, Value
*, const SimplifyQuery
&,
60 static Value
*simplifyUnOp(unsigned, Value
*, const SimplifyQuery
&, unsigned);
61 static Value
*simplifyFPUnOp(unsigned, Value
*, const FastMathFlags
&,
62 const SimplifyQuery
&, unsigned);
63 static Value
*simplifyBinOp(unsigned, Value
*, Value
*, const SimplifyQuery
&,
65 static Value
*simplifyBinOp(unsigned, Value
*, Value
*, const FastMathFlags
&,
66 const SimplifyQuery
&, unsigned);
67 static Value
*simplifyCmpInst(CmpPredicate
, Value
*, Value
*,
68 const SimplifyQuery
&, unsigned);
69 static Value
*simplifyICmpInst(CmpPredicate Predicate
, Value
*LHS
, Value
*RHS
,
70 const SimplifyQuery
&Q
, unsigned MaxRecurse
);
71 static Value
*simplifyOrInst(Value
*, Value
*, const SimplifyQuery
&, unsigned);
72 static Value
*simplifyXorInst(Value
*, Value
*, const SimplifyQuery
&,
74 static Value
*simplifyCastInst(unsigned, Value
*, Type
*, const SimplifyQuery
&,
76 static Value
*simplifyGEPInst(Type
*, Value
*, ArrayRef
<Value
*>,
77 GEPNoWrapFlags
, const SimplifyQuery
&, unsigned);
78 static Value
*simplifySelectInst(Value
*, Value
*, Value
*,
79 const SimplifyQuery
&, unsigned);
80 static Value
*simplifyInstructionWithOperands(Instruction
*I
,
81 ArrayRef
<Value
*> NewOps
,
82 const SimplifyQuery
&SQ
,
85 /// For a boolean type or a vector of boolean type, return false or a vector
86 /// with every element false.
87 static Constant
*getFalse(Type
*Ty
) { return ConstantInt::getFalse(Ty
); }
89 /// For a boolean type or a vector of boolean type, return true or a vector
90 /// with every element true.
91 static Constant
*getTrue(Type
*Ty
) { return ConstantInt::getTrue(Ty
); }
93 /// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"?
94 static bool isSameCompare(Value
*V
, CmpPredicate Pred
, Value
*LHS
, Value
*RHS
) {
95 CmpInst
*Cmp
= dyn_cast
<CmpInst
>(V
);
98 CmpInst::Predicate CPred
= Cmp
->getPredicate();
99 Value
*CLHS
= Cmp
->getOperand(0), *CRHS
= Cmp
->getOperand(1);
100 if (CPred
== Pred
&& CLHS
== LHS
&& CRHS
== RHS
)
102 return CPred
== CmpInst::getSwappedPredicate(Pred
) && CLHS
== RHS
&&
106 /// Simplify comparison with true or false branch of select:
107 /// %sel = select i1 %cond, i32 %tv, i32 %fv
108 /// %cmp = icmp sle i32 %sel, %rhs
109 /// Compose new comparison by substituting %sel with either %tv or %fv
110 /// and see if it simplifies.
111 static Value
*simplifyCmpSelCase(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
112 Value
*Cond
, const SimplifyQuery
&Q
,
113 unsigned MaxRecurse
, Constant
*TrueOrFalse
) {
114 Value
*SimplifiedCmp
= simplifyCmpInst(Pred
, LHS
, RHS
, Q
, MaxRecurse
);
115 if (SimplifiedCmp
== Cond
) {
116 // %cmp simplified to the select condition (%cond).
118 } else if (!SimplifiedCmp
&& isSameCompare(Cond
, Pred
, LHS
, RHS
)) {
119 // It didn't simplify. However, if composed comparison is equivalent
120 // to the select condition (%cond) then we can replace it.
123 return SimplifiedCmp
;
126 /// Simplify comparison with true branch of select
127 static Value
*simplifyCmpSelTrueCase(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
128 Value
*Cond
, const SimplifyQuery
&Q
,
129 unsigned MaxRecurse
) {
130 return simplifyCmpSelCase(Pred
, LHS
, RHS
, Cond
, Q
, MaxRecurse
,
131 getTrue(Cond
->getType()));
134 /// Simplify comparison with false branch of select
135 static Value
*simplifyCmpSelFalseCase(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
136 Value
*Cond
, const SimplifyQuery
&Q
,
137 unsigned MaxRecurse
) {
138 return simplifyCmpSelCase(Pred
, LHS
, RHS
, Cond
, Q
, MaxRecurse
,
139 getFalse(Cond
->getType()));
142 /// We know comparison with both branches of select can be simplified, but they
143 /// are not equal. This routine handles some logical simplifications.
144 static Value
*handleOtherCmpSelSimplifications(Value
*TCmp
, Value
*FCmp
,
146 const SimplifyQuery
&Q
,
147 unsigned MaxRecurse
) {
148 // If the false value simplified to false, then the result of the compare
149 // is equal to "Cond && TCmp". This also catches the case when the false
150 // value simplified to false and the true value to true, returning "Cond".
151 // Folding select to and/or isn't poison-safe in general; impliesPoison
152 // checks whether folding it does not convert a well-defined value into
154 if (match(FCmp
, m_Zero()) && impliesPoison(TCmp
, Cond
))
155 if (Value
*V
= simplifyAndInst(Cond
, TCmp
, Q
, MaxRecurse
))
157 // If the true value simplified to true, then the result of the compare
158 // is equal to "Cond || FCmp".
159 if (match(TCmp
, m_One()) && impliesPoison(FCmp
, Cond
))
160 if (Value
*V
= simplifyOrInst(Cond
, FCmp
, Q
, MaxRecurse
))
162 // Finally, if the false value simplified to true and the true value to
163 // false, then the result of the compare is equal to "!Cond".
164 if (match(FCmp
, m_One()) && match(TCmp
, m_Zero()))
165 if (Value
*V
= simplifyXorInst(
166 Cond
, Constant::getAllOnesValue(Cond
->getType()), Q
, MaxRecurse
))
171 /// Does the given value dominate the specified phi node?
172 static bool valueDominatesPHI(Value
*V
, PHINode
*P
, const DominatorTree
*DT
) {
173 Instruction
*I
= dyn_cast
<Instruction
>(V
);
175 // Arguments and constants dominate all instructions.
178 // If we have a DominatorTree then do a precise test.
180 return DT
->dominates(I
, P
);
182 // Otherwise, if the instruction is in the entry block and is not an invoke,
183 // then it obviously dominates all phi nodes.
184 if (I
->getParent()->isEntryBlock() && !isa
<InvokeInst
>(I
) &&
191 /// Try to simplify a binary operator of form "V op OtherOp" where V is
192 /// "(B0 opex B1)" by distributing 'op' across 'opex' as
193 /// "(B0 op OtherOp) opex (B1 op OtherOp)".
194 static Value
*expandBinOp(Instruction::BinaryOps Opcode
, Value
*V
,
195 Value
*OtherOp
, Instruction::BinaryOps OpcodeToExpand
,
196 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
197 auto *B
= dyn_cast
<BinaryOperator
>(V
);
198 if (!B
|| B
->getOpcode() != OpcodeToExpand
)
200 Value
*B0
= B
->getOperand(0), *B1
= B
->getOperand(1);
202 simplifyBinOp(Opcode
, B0
, OtherOp
, Q
.getWithoutUndef(), MaxRecurse
);
206 simplifyBinOp(Opcode
, B1
, OtherOp
, Q
.getWithoutUndef(), MaxRecurse
);
210 // Does the expanded pair of binops simplify to the existing binop?
211 if ((L
== B0
&& R
== B1
) ||
212 (Instruction::isCommutative(OpcodeToExpand
) && L
== B1
&& R
== B0
)) {
217 // Otherwise, return "L op' R" if it simplifies.
218 Value
*S
= simplifyBinOp(OpcodeToExpand
, L
, R
, Q
, MaxRecurse
);
226 /// Try to simplify binops of form "A op (B op' C)" or the commuted variant by
227 /// distributing op over op'.
228 static Value
*expandCommutativeBinOp(Instruction::BinaryOps Opcode
, Value
*L
,
230 Instruction::BinaryOps OpcodeToExpand
,
231 const SimplifyQuery
&Q
,
232 unsigned MaxRecurse
) {
233 // Recursion is always used, so bail out at once if we already hit the limit.
237 if (Value
*V
= expandBinOp(Opcode
, L
, R
, OpcodeToExpand
, Q
, MaxRecurse
))
239 if (Value
*V
= expandBinOp(Opcode
, R
, L
, OpcodeToExpand
, Q
, MaxRecurse
))
244 /// Generic simplifications for associative binary operations.
245 /// Returns the simpler value, or null if none was found.
246 static Value
*simplifyAssociativeBinOp(Instruction::BinaryOps Opcode
,
247 Value
*LHS
, Value
*RHS
,
248 const SimplifyQuery
&Q
,
249 unsigned MaxRecurse
) {
250 assert(Instruction::isAssociative(Opcode
) && "Not an associative operation!");
252 // Recursion is always used, so bail out at once if we already hit the limit.
256 BinaryOperator
*Op0
= dyn_cast
<BinaryOperator
>(LHS
);
257 BinaryOperator
*Op1
= dyn_cast
<BinaryOperator
>(RHS
);
259 // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely.
260 if (Op0
&& Op0
->getOpcode() == Opcode
) {
261 Value
*A
= Op0
->getOperand(0);
262 Value
*B
= Op0
->getOperand(1);
265 // Does "B op C" simplify?
266 if (Value
*V
= simplifyBinOp(Opcode
, B
, C
, Q
, MaxRecurse
)) {
267 // It does! Return "A op V" if it simplifies or is already available.
268 // If V equals B then "A op V" is just the LHS.
271 // Otherwise return "A op V" if it simplifies.
272 if (Value
*W
= simplifyBinOp(Opcode
, A
, V
, Q
, MaxRecurse
)) {
279 // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely.
280 if (Op1
&& Op1
->getOpcode() == Opcode
) {
282 Value
*B
= Op1
->getOperand(0);
283 Value
*C
= Op1
->getOperand(1);
285 // Does "A op B" simplify?
286 if (Value
*V
= simplifyBinOp(Opcode
, A
, B
, Q
, MaxRecurse
)) {
287 // It does! Return "V op C" if it simplifies or is already available.
288 // If V equals B then "V op C" is just the RHS.
291 // Otherwise return "V op C" if it simplifies.
292 if (Value
*W
= simplifyBinOp(Opcode
, V
, C
, Q
, MaxRecurse
)) {
299 // The remaining transforms require commutativity as well as associativity.
300 if (!Instruction::isCommutative(Opcode
))
303 // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely.
304 if (Op0
&& Op0
->getOpcode() == Opcode
) {
305 Value
*A
= Op0
->getOperand(0);
306 Value
*B
= Op0
->getOperand(1);
309 // Does "C op A" simplify?
310 if (Value
*V
= simplifyBinOp(Opcode
, C
, A
, Q
, MaxRecurse
)) {
311 // It does! Return "V op B" if it simplifies or is already available.
312 // If V equals A then "V op B" is just the LHS.
315 // Otherwise return "V op B" if it simplifies.
316 if (Value
*W
= simplifyBinOp(Opcode
, V
, B
, Q
, MaxRecurse
)) {
323 // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely.
324 if (Op1
&& Op1
->getOpcode() == Opcode
) {
326 Value
*B
= Op1
->getOperand(0);
327 Value
*C
= Op1
->getOperand(1);
329 // Does "C op A" simplify?
330 if (Value
*V
= simplifyBinOp(Opcode
, C
, A
, Q
, MaxRecurse
)) {
331 // It does! Return "B op V" if it simplifies or is already available.
332 // If V equals C then "B op V" is just the RHS.
335 // Otherwise return "B op V" if it simplifies.
336 if (Value
*W
= simplifyBinOp(Opcode
, B
, V
, Q
, MaxRecurse
)) {
346 /// In the case of a binary operation with a select instruction as an operand,
347 /// try to simplify the binop by seeing whether evaluating it on both branches
348 /// of the select results in the same value. Returns the common value if so,
349 /// otherwise returns null.
350 static Value
*threadBinOpOverSelect(Instruction::BinaryOps Opcode
, Value
*LHS
,
351 Value
*RHS
, const SimplifyQuery
&Q
,
352 unsigned MaxRecurse
) {
353 // Recursion is always used, so bail out at once if we already hit the limit.
358 if (isa
<SelectInst
>(LHS
)) {
359 SI
= cast
<SelectInst
>(LHS
);
361 assert(isa
<SelectInst
>(RHS
) && "No select instruction operand!");
362 SI
= cast
<SelectInst
>(RHS
);
365 // Evaluate the BinOp on the true and false branches of the select.
369 TV
= simplifyBinOp(Opcode
, SI
->getTrueValue(), RHS
, Q
, MaxRecurse
);
370 FV
= simplifyBinOp(Opcode
, SI
->getFalseValue(), RHS
, Q
, MaxRecurse
);
372 TV
= simplifyBinOp(Opcode
, LHS
, SI
->getTrueValue(), Q
, MaxRecurse
);
373 FV
= simplifyBinOp(Opcode
, LHS
, SI
->getFalseValue(), Q
, MaxRecurse
);
376 // If they simplified to the same value, then return the common value.
377 // If they both failed to simplify then return null.
381 // If one branch simplified to undef, return the other one.
382 if (TV
&& Q
.isUndefValue(TV
))
384 if (FV
&& Q
.isUndefValue(FV
))
387 // If applying the operation did not change the true and false select values,
388 // then the result of the binop is the select itself.
389 if (TV
== SI
->getTrueValue() && FV
== SI
->getFalseValue())
392 // If one branch simplified and the other did not, and the simplified
393 // value is equal to the unsimplified one, return the simplified value.
394 // For example, select (cond, X, X & Z) & Z -> X & Z.
395 if ((FV
&& !TV
) || (TV
&& !FV
)) {
396 // Check that the simplified value has the form "X op Y" where "op" is the
397 // same as the original operation.
398 Instruction
*Simplified
= dyn_cast
<Instruction
>(FV
? FV
: TV
);
399 if (Simplified
&& Simplified
->getOpcode() == unsigned(Opcode
) &&
400 !Simplified
->hasPoisonGeneratingFlags()) {
401 // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS".
402 // We already know that "op" is the same as for the simplified value. See
403 // if the operands match too. If so, return the simplified value.
404 Value
*UnsimplifiedBranch
= FV
? SI
->getTrueValue() : SI
->getFalseValue();
405 Value
*UnsimplifiedLHS
= SI
== LHS
? UnsimplifiedBranch
: LHS
;
406 Value
*UnsimplifiedRHS
= SI
== LHS
? RHS
: UnsimplifiedBranch
;
407 if (Simplified
->getOperand(0) == UnsimplifiedLHS
&&
408 Simplified
->getOperand(1) == UnsimplifiedRHS
)
410 if (Simplified
->isCommutative() &&
411 Simplified
->getOperand(1) == UnsimplifiedLHS
&&
412 Simplified
->getOperand(0) == UnsimplifiedRHS
)
420 /// In the case of a comparison with a select instruction, try to simplify the
421 /// comparison by seeing whether both branches of the select result in the same
422 /// value. Returns the common value if so, otherwise returns null.
423 /// For example, if we have:
424 /// %tmp = select i1 %cmp, i32 1, i32 2
425 /// %cmp1 = icmp sle i32 %tmp, 3
426 /// We can simplify %cmp1 to true, because both branches of select are
427 /// less than 3. We compose new comparison by substituting %tmp with both
428 /// branches of select and see if it can be simplified.
429 static Value
*threadCmpOverSelect(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
430 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
431 // Recursion is always used, so bail out at once if we already hit the limit.
435 // Make sure the select is on the LHS.
436 if (!isa
<SelectInst
>(LHS
)) {
438 Pred
= CmpInst::getSwappedPredicate(Pred
);
440 assert(isa
<SelectInst
>(LHS
) && "Not comparing with a select instruction!");
441 SelectInst
*SI
= cast
<SelectInst
>(LHS
);
442 Value
*Cond
= SI
->getCondition();
443 Value
*TV
= SI
->getTrueValue();
444 Value
*FV
= SI
->getFalseValue();
446 // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it.
447 // Does "cmp TV, RHS" simplify?
448 Value
*TCmp
= simplifyCmpSelTrueCase(Pred
, TV
, RHS
, Cond
, Q
, MaxRecurse
);
452 // Does "cmp FV, RHS" simplify?
453 Value
*FCmp
= simplifyCmpSelFalseCase(Pred
, FV
, RHS
, Cond
, Q
, MaxRecurse
);
457 // If both sides simplified to the same value, then use it as the result of
458 // the original comparison.
462 // The remaining cases only make sense if the select condition has the same
463 // type as the result of the comparison, so bail out if this is not so.
464 if (Cond
->getType()->isVectorTy() == RHS
->getType()->isVectorTy())
465 return handleOtherCmpSelSimplifications(TCmp
, FCmp
, Cond
, Q
, MaxRecurse
);
470 /// In the case of a binary operation with an operand that is a PHI instruction,
471 /// try to simplify the binop by seeing whether evaluating it on the incoming
472 /// phi values yields the same result for every value. If so returns the common
473 /// value, otherwise returns null.
474 static Value
*threadBinOpOverPHI(Instruction::BinaryOps Opcode
, Value
*LHS
,
475 Value
*RHS
, const SimplifyQuery
&Q
,
476 unsigned MaxRecurse
) {
477 // Recursion is always used, so bail out at once if we already hit the limit.
482 if (isa
<PHINode
>(LHS
)) {
483 PI
= cast
<PHINode
>(LHS
);
484 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
485 if (!valueDominatesPHI(RHS
, PI
, Q
.DT
))
488 assert(isa
<PHINode
>(RHS
) && "No PHI instruction operand!");
489 PI
= cast
<PHINode
>(RHS
);
490 // Bail out if LHS and the phi may be mutually interdependent due to a loop.
491 if (!valueDominatesPHI(LHS
, PI
, Q
.DT
))
495 // Evaluate the BinOp on the incoming phi values.
496 Value
*CommonValue
= nullptr;
497 for (Use
&Incoming
: PI
->incoming_values()) {
498 // If the incoming value is the phi node itself, it can safely be skipped.
501 Instruction
*InTI
= PI
->getIncomingBlock(Incoming
)->getTerminator();
503 ? simplifyBinOp(Opcode
, Incoming
, RHS
,
504 Q
.getWithInstruction(InTI
), MaxRecurse
)
505 : simplifyBinOp(Opcode
, LHS
, Incoming
,
506 Q
.getWithInstruction(InTI
), MaxRecurse
);
507 // If the operation failed to simplify, or simplified to a different value
508 // to previously, then give up.
509 if (!V
|| (CommonValue
&& V
!= CommonValue
))
517 /// In the case of a comparison with a PHI instruction, try to simplify the
518 /// comparison by seeing whether comparing with all of the incoming phi values
519 /// yields the same result every time. If so returns the common result,
520 /// otherwise returns null.
521 static Value
*threadCmpOverPHI(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
522 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
523 // Recursion is always used, so bail out at once if we already hit the limit.
527 // Make sure the phi is on the LHS.
528 if (!isa
<PHINode
>(LHS
)) {
530 Pred
= CmpInst::getSwappedPredicate(Pred
);
532 assert(isa
<PHINode
>(LHS
) && "Not comparing with a phi instruction!");
533 PHINode
*PI
= cast
<PHINode
>(LHS
);
535 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
536 if (!valueDominatesPHI(RHS
, PI
, Q
.DT
))
539 // Evaluate the BinOp on the incoming phi values.
540 Value
*CommonValue
= nullptr;
541 for (unsigned u
= 0, e
= PI
->getNumIncomingValues(); u
< e
; ++u
) {
542 Value
*Incoming
= PI
->getIncomingValue(u
);
543 Instruction
*InTI
= PI
->getIncomingBlock(u
)->getTerminator();
544 // If the incoming value is the phi node itself, it can safely be skipped.
547 // Change the context instruction to the "edge" that flows into the phi.
548 // This is important because that is where incoming is actually "evaluated"
549 // even though it is used later somewhere else.
550 Value
*V
= simplifyCmpInst(Pred
, Incoming
, RHS
, Q
.getWithInstruction(InTI
),
552 // If the operation failed to simplify, or simplified to a different value
553 // to previously, then give up.
554 if (!V
|| (CommonValue
&& V
!= CommonValue
))
562 static Constant
*foldOrCommuteConstant(Instruction::BinaryOps Opcode
,
563 Value
*&Op0
, Value
*&Op1
,
564 const SimplifyQuery
&Q
) {
565 if (auto *CLHS
= dyn_cast
<Constant
>(Op0
)) {
566 if (auto *CRHS
= dyn_cast
<Constant
>(Op1
)) {
570 case Instruction::FAdd
:
571 case Instruction::FSub
:
572 case Instruction::FMul
:
573 case Instruction::FDiv
:
574 case Instruction::FRem
:
575 if (Q
.CxtI
!= nullptr)
576 return ConstantFoldFPInstOperands(Opcode
, CLHS
, CRHS
, Q
.DL
, Q
.CxtI
);
578 return ConstantFoldBinaryOpOperands(Opcode
, CLHS
, CRHS
, Q
.DL
);
581 // Canonicalize the constant to the RHS if this is a commutative operation.
582 if (Instruction::isCommutative(Opcode
))
588 /// Given operands for an Add, see if we can fold the result.
589 /// If not, this returns null.
590 static Value
*simplifyAddInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
591 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
592 if (Constant
*C
= foldOrCommuteConstant(Instruction::Add
, Op0
, Op1
, Q
))
595 // X + poison -> poison
596 if (isa
<PoisonValue
>(Op1
))
599 // X + undef -> undef
600 if (Q
.isUndefValue(Op1
))
604 if (match(Op1
, m_Zero()))
607 // If two operands are negative, return 0.
608 if (isKnownNegation(Op0
, Op1
))
609 return Constant::getNullValue(Op0
->getType());
615 if (match(Op1
, m_Sub(m_Value(Y
), m_Specific(Op0
))) ||
616 match(Op0
, m_Sub(m_Value(Y
), m_Specific(Op1
))))
619 // X + ~X -> -1 since ~X = -X-1
620 Type
*Ty
= Op0
->getType();
621 if (match(Op0
, m_Not(m_Specific(Op1
))) || match(Op1
, m_Not(m_Specific(Op0
))))
622 return Constant::getAllOnesValue(Ty
);
624 // add nsw/nuw (xor Y, signmask), signmask --> Y
625 // The no-wrapping add guarantees that the top bit will be set by the add.
626 // Therefore, the xor must be clearing the already set sign bit of Y.
627 if ((IsNSW
|| IsNUW
) && match(Op1
, m_SignMask()) &&
628 match(Op0
, m_Xor(m_Value(Y
), m_SignMask())))
631 // add nuw %x, -1 -> -1, because %x can only be 0.
632 if (IsNUW
&& match(Op1
, m_AllOnes()))
633 return Op1
; // Which is -1.
636 if (MaxRecurse
&& Op0
->getType()->isIntOrIntVectorTy(1))
637 if (Value
*V
= simplifyXorInst(Op0
, Op1
, Q
, MaxRecurse
- 1))
640 // Try some generic simplifications for associative operations.
642 simplifyAssociativeBinOp(Instruction::Add
, Op0
, Op1
, Q
, MaxRecurse
))
645 // Threading Add over selects and phi nodes is pointless, so don't bother.
646 // Threading over the select in "A + select(cond, B, C)" means evaluating
647 // "A+B" and "A+C" and seeing if they are equal; but they are equal if and
648 // only if B and C are equal. If B and C are equal then (since we assume
649 // that operands have already been simplified) "select(cond, B, C)" should
650 // have been simplified to the common value of B and C already. Analysing
651 // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
652 // for threading over phi nodes.
657 Value
*llvm::simplifyAddInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
658 const SimplifyQuery
&Query
) {
659 return ::simplifyAddInst(Op0
, Op1
, IsNSW
, IsNUW
, Query
, RecursionLimit
);
662 /// Compute the base pointer and cumulative constant offsets for V.
664 /// This strips all constant offsets off of V, leaving it the base pointer, and
665 /// accumulates the total constant offset applied in the returned constant.
666 /// It returns zero if there are no constant offsets applied.
668 /// This is very similar to stripAndAccumulateConstantOffsets(), except it
669 /// normalizes the offset bitwidth to the stripped pointer type, not the
670 /// original pointer type.
671 static APInt
stripAndComputeConstantOffsets(const DataLayout
&DL
, Value
*&V
,
672 bool AllowNonInbounds
= false) {
673 assert(V
->getType()->isPtrOrPtrVectorTy());
675 APInt Offset
= APInt::getZero(DL
.getIndexTypeSizeInBits(V
->getType()));
676 V
= V
->stripAndAccumulateConstantOffsets(DL
, Offset
, AllowNonInbounds
);
677 // As that strip may trace through `addrspacecast`, need to sext or trunc
678 // the offset calculated.
679 return Offset
.sextOrTrunc(DL
.getIndexTypeSizeInBits(V
->getType()));
682 /// Compute the constant difference between two pointer values.
683 /// If the difference is not a constant, returns zero.
684 static Constant
*computePointerDifference(const DataLayout
&DL
, Value
*LHS
,
686 APInt LHSOffset
= stripAndComputeConstantOffsets(DL
, LHS
);
687 APInt RHSOffset
= stripAndComputeConstantOffsets(DL
, RHS
);
689 // If LHS and RHS are not related via constant offsets to the same base
690 // value, there is nothing we can do here.
694 // Otherwise, the difference of LHS - RHS can be computed as:
696 // = (LHSOffset + Base) - (RHSOffset + Base)
697 // = LHSOffset - RHSOffset
698 Constant
*Res
= ConstantInt::get(LHS
->getContext(), LHSOffset
- RHSOffset
);
699 if (auto *VecTy
= dyn_cast
<VectorType
>(LHS
->getType()))
700 Res
= ConstantVector::getSplat(VecTy
->getElementCount(), Res
);
704 /// Test if there is a dominating equivalence condition for the
705 /// two operands. If there is, try to reduce the binary operation
706 /// between the two operands.
707 /// Example: Op0 - Op1 --> 0 when Op0 == Op1
708 static Value
*simplifyByDomEq(unsigned Opcode
, Value
*Op0
, Value
*Op1
,
709 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
710 // Recursive run it can not get any benefit
711 if (MaxRecurse
!= RecursionLimit
)
714 std::optional
<bool> Imp
=
715 isImpliedByDomCondition(CmpInst::ICMP_EQ
, Op0
, Op1
, Q
.CxtI
, Q
.DL
);
717 Type
*Ty
= Op0
->getType();
719 case Instruction::Sub
:
720 case Instruction::Xor
:
721 case Instruction::URem
:
722 case Instruction::SRem
:
723 return Constant::getNullValue(Ty
);
725 case Instruction::SDiv
:
726 case Instruction::UDiv
:
727 return ConstantInt::get(Ty
, 1);
729 case Instruction::And
:
730 case Instruction::Or
:
731 // Could be either one - choose Op1 since that's more likely a constant.
740 /// Given operands for a Sub, see if we can fold the result.
741 /// If not, this returns null.
742 static Value
*simplifySubInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
743 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
744 if (Constant
*C
= foldOrCommuteConstant(Instruction::Sub
, Op0
, Op1
, Q
))
747 // X - poison -> poison
748 // poison - X -> poison
749 if (isa
<PoisonValue
>(Op0
) || isa
<PoisonValue
>(Op1
))
750 return PoisonValue::get(Op0
->getType());
752 // X - undef -> undef
753 // undef - X -> undef
754 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
755 return UndefValue::get(Op0
->getType());
758 if (match(Op1
, m_Zero()))
763 return Constant::getNullValue(Op0
->getType());
765 // Is this a negation?
766 if (match(Op0
, m_Zero())) {
767 // 0 - X -> 0 if the sub is NUW.
769 return Constant::getNullValue(Op0
->getType());
771 KnownBits Known
= computeKnownBits(Op1
, /* Depth */ 0, Q
);
772 if (Known
.Zero
.isMaxSignedValue()) {
773 // Op1 is either 0 or the minimum signed value. If the sub is NSW, then
774 // Op1 must be 0 because negating the minimum signed value is undefined.
776 return Constant::getNullValue(Op0
->getType());
778 // 0 - X -> X if X is 0 or the minimum signed value.
783 // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
784 // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
785 Value
*X
= nullptr, *Y
= nullptr, *Z
= Op1
;
786 if (MaxRecurse
&& match(Op0
, m_Add(m_Value(X
), m_Value(Y
)))) { // (X + Y) - Z
787 // See if "V === Y - Z" simplifies.
788 if (Value
*V
= simplifyBinOp(Instruction::Sub
, Y
, Z
, Q
, MaxRecurse
- 1))
789 // It does! Now see if "X + V" simplifies.
790 if (Value
*W
= simplifyBinOp(Instruction::Add
, X
, V
, Q
, MaxRecurse
- 1)) {
791 // It does, we successfully reassociated!
795 // See if "V === X - Z" simplifies.
796 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Z
, Q
, MaxRecurse
- 1))
797 // It does! Now see if "Y + V" simplifies.
798 if (Value
*W
= simplifyBinOp(Instruction::Add
, Y
, V
, Q
, MaxRecurse
- 1)) {
799 // It does, we successfully reassociated!
805 // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
806 // For example, X - (X + 1) -> -1
808 if (MaxRecurse
&& match(Op1
, m_Add(m_Value(Y
), m_Value(Z
)))) { // X - (Y + Z)
809 // See if "V === X - Y" simplifies.
810 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Y
, Q
, MaxRecurse
- 1))
811 // It does! Now see if "V - Z" simplifies.
812 if (Value
*W
= simplifyBinOp(Instruction::Sub
, V
, Z
, Q
, MaxRecurse
- 1)) {
813 // It does, we successfully reassociated!
817 // See if "V === X - Z" simplifies.
818 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Z
, Q
, MaxRecurse
- 1))
819 // It does! Now see if "V - Y" simplifies.
820 if (Value
*W
= simplifyBinOp(Instruction::Sub
, V
, Y
, Q
, MaxRecurse
- 1)) {
821 // It does, we successfully reassociated!
827 // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
828 // For example, X - (X - Y) -> Y.
830 if (MaxRecurse
&& match(Op1
, m_Sub(m_Value(X
), m_Value(Y
)))) // Z - (X - Y)
831 // See if "V === Z - X" simplifies.
832 if (Value
*V
= simplifyBinOp(Instruction::Sub
, Z
, X
, Q
, MaxRecurse
- 1))
833 // It does! Now see if "V + Y" simplifies.
834 if (Value
*W
= simplifyBinOp(Instruction::Add
, V
, Y
, Q
, MaxRecurse
- 1)) {
835 // It does, we successfully reassociated!
840 // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
841 if (MaxRecurse
&& match(Op0
, m_Trunc(m_Value(X
))) &&
842 match(Op1
, m_Trunc(m_Value(Y
))))
843 if (X
->getType() == Y
->getType())
844 // See if "V === X - Y" simplifies.
845 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Y
, Q
, MaxRecurse
- 1))
846 // It does! Now see if "trunc V" simplifies.
847 if (Value
*W
= simplifyCastInst(Instruction::Trunc
, V
, Op0
->getType(),
849 // It does, return the simplified "trunc V".
852 // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
853 if (match(Op0
, m_PtrToInt(m_Value(X
))) && match(Op1
, m_PtrToInt(m_Value(Y
))))
854 if (Constant
*Result
= computePointerDifference(Q
.DL
, X
, Y
))
855 return ConstantFoldIntegerCast(Result
, Op0
->getType(), /*IsSigned*/ true,
859 if (MaxRecurse
&& Op0
->getType()->isIntOrIntVectorTy(1))
860 if (Value
*V
= simplifyXorInst(Op0
, Op1
, Q
, MaxRecurse
- 1))
863 // Threading Sub over selects and phi nodes is pointless, so don't bother.
864 // Threading over the select in "A - select(cond, B, C)" means evaluating
865 // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
866 // only if B and C are equal. If B and C are equal then (since we assume
867 // that operands have already been simplified) "select(cond, B, C)" should
868 // have been simplified to the common value of B and C already. Analysing
869 // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
870 // for threading over phi nodes.
872 if (Value
*V
= simplifyByDomEq(Instruction::Sub
, Op0
, Op1
, Q
, MaxRecurse
))
875 // (sub nuw C_Mask, (xor X, C_Mask)) -> X
878 if (match(Op1
, m_Xor(m_Value(X
), m_Specific(Op0
))) &&
879 match(Op0
, m_LowBitMask()))
886 Value
*llvm::simplifySubInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
887 const SimplifyQuery
&Q
) {
888 return ::simplifySubInst(Op0
, Op1
, IsNSW
, IsNUW
, Q
, RecursionLimit
);
891 /// Given operands for a Mul, see if we can fold the result.
892 /// If not, this returns null.
893 static Value
*simplifyMulInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
894 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
895 if (Constant
*C
= foldOrCommuteConstant(Instruction::Mul
, Op0
, Op1
, Q
))
898 // X * poison -> poison
899 if (isa
<PoisonValue
>(Op1
))
904 if (Q
.isUndefValue(Op1
) || match(Op1
, m_Zero()))
905 return Constant::getNullValue(Op0
->getType());
908 if (match(Op1
, m_One()))
911 // (X / Y) * Y -> X if the division is exact.
913 if (Q
.IIQ
.UseInstrInfo
&&
915 m_Exact(m_IDiv(m_Value(X
), m_Specific(Op1
)))) || // (X / Y) * Y
916 match(Op1
, m_Exact(m_IDiv(m_Value(X
), m_Specific(Op0
)))))) // Y * (X / Y)
919 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
920 // mul i1 nsw is a special-case because -1 * -1 is poison (+1 is not
921 // representable). All other cases reduce to 0, so just return 0.
923 return ConstantInt::getNullValue(Op0
->getType());
925 // Treat "mul i1" as "and i1".
927 if (Value
*V
= simplifyAndInst(Op0
, Op1
, Q
, MaxRecurse
- 1))
931 // Try some generic simplifications for associative operations.
933 simplifyAssociativeBinOp(Instruction::Mul
, Op0
, Op1
, Q
, MaxRecurse
))
936 // Mul distributes over Add. Try some generic simplifications based on this.
937 if (Value
*V
= expandCommutativeBinOp(Instruction::Mul
, Op0
, Op1
,
938 Instruction::Add
, Q
, MaxRecurse
))
941 // If the operation is with the result of a select instruction, check whether
942 // operating on either branch of the select always yields the same value.
943 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
))
945 threadBinOpOverSelect(Instruction::Mul
, Op0
, Op1
, Q
, MaxRecurse
))
948 // If the operation is with the result of a phi instruction, check whether
949 // operating on all incoming values of the phi always yields the same value.
950 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
952 threadBinOpOverPHI(Instruction::Mul
, Op0
, Op1
, Q
, MaxRecurse
))
958 Value
*llvm::simplifyMulInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
959 const SimplifyQuery
&Q
) {
960 return ::simplifyMulInst(Op0
, Op1
, IsNSW
, IsNUW
, Q
, RecursionLimit
);
963 /// Given a predicate and two operands, return true if the comparison is true.
964 /// This is a helper for div/rem simplification where we return some other value
965 /// when we can prove a relationship between the operands.
966 static bool isICmpTrue(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
967 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
968 Value
*V
= simplifyICmpInst(Pred
, LHS
, RHS
, Q
, MaxRecurse
);
969 Constant
*C
= dyn_cast_or_null
<Constant
>(V
);
970 return (C
&& C
->isAllOnesValue());
973 /// Return true if we can simplify X / Y to 0. Remainder can adapt that answer
974 /// to simplify X % Y to X.
975 static bool isDivZero(Value
*X
, Value
*Y
, const SimplifyQuery
&Q
,
976 unsigned MaxRecurse
, bool IsSigned
) {
977 // Recursion is always used, so bail out at once if we already hit the limit.
982 // (X srem Y) sdiv Y --> 0
983 if (match(X
, m_SRem(m_Value(), m_Specific(Y
))))
988 // We require that 1 operand is a simple constant. That could be extended to
989 // 2 variables if we computed the sign bit for each.
991 // Make sure that a constant is not the minimum signed value because taking
992 // the abs() of that is undefined.
993 Type
*Ty
= X
->getType();
995 if (match(X
, m_APInt(C
)) && !C
->isMinSignedValue()) {
996 // Is the variable divisor magnitude always greater than the constant
997 // dividend magnitude?
998 // |Y| > |C| --> Y < -abs(C) or Y > abs(C)
999 Constant
*PosDividendC
= ConstantInt::get(Ty
, C
->abs());
1000 Constant
*NegDividendC
= ConstantInt::get(Ty
, -C
->abs());
1001 if (isICmpTrue(CmpInst::ICMP_SLT
, Y
, NegDividendC
, Q
, MaxRecurse
) ||
1002 isICmpTrue(CmpInst::ICMP_SGT
, Y
, PosDividendC
, Q
, MaxRecurse
))
1005 if (match(Y
, m_APInt(C
))) {
1006 // Special-case: we can't take the abs() of a minimum signed value. If
1007 // that's the divisor, then all we have to do is prove that the dividend
1008 // is also not the minimum signed value.
1009 if (C
->isMinSignedValue())
1010 return isICmpTrue(CmpInst::ICMP_NE
, X
, Y
, Q
, MaxRecurse
);
1012 // Is the variable dividend magnitude always less than the constant
1013 // divisor magnitude?
1014 // |X| < |C| --> X > -abs(C) and X < abs(C)
1015 Constant
*PosDivisorC
= ConstantInt::get(Ty
, C
->abs());
1016 Constant
*NegDivisorC
= ConstantInt::get(Ty
, -C
->abs());
1017 if (isICmpTrue(CmpInst::ICMP_SGT
, X
, NegDivisorC
, Q
, MaxRecurse
) &&
1018 isICmpTrue(CmpInst::ICMP_SLT
, X
, PosDivisorC
, Q
, MaxRecurse
))
1024 // IsSigned == false.
1026 // Is the unsigned dividend known to be less than a constant divisor?
1027 // TODO: Convert this (and above) to range analysis
1028 // ("computeConstantRangeIncludingKnownBits")?
1030 if (match(Y
, m_APInt(C
)) &&
1031 computeKnownBits(X
, /* Depth */ 0, Q
).getMaxValue().ult(*C
))
1034 // Try again for any divisor:
1035 // Is the dividend unsigned less than the divisor?
1036 return isICmpTrue(ICmpInst::ICMP_ULT
, X
, Y
, Q
, MaxRecurse
);
1039 /// Check for common or similar folds of integer division or integer remainder.
1040 /// This applies to all 4 opcodes (sdiv/udiv/srem/urem).
1041 static Value
*simplifyDivRem(Instruction::BinaryOps Opcode
, Value
*Op0
,
1042 Value
*Op1
, const SimplifyQuery
&Q
,
1043 unsigned MaxRecurse
) {
1044 bool IsDiv
= (Opcode
== Instruction::SDiv
|| Opcode
== Instruction::UDiv
);
1045 bool IsSigned
= (Opcode
== Instruction::SDiv
|| Opcode
== Instruction::SRem
);
1047 Type
*Ty
= Op0
->getType();
1049 // X / undef -> poison
1050 // X % undef -> poison
1051 if (Q
.isUndefValue(Op1
) || isa
<PoisonValue
>(Op1
))
1052 return PoisonValue::get(Ty
);
1056 // We don't need to preserve faults!
1057 if (match(Op1
, m_Zero()))
1058 return PoisonValue::get(Ty
);
1060 // poison / X -> poison
1061 // poison % X -> poison
1062 if (isa
<PoisonValue
>(Op0
))
1067 if (Q
.isUndefValue(Op0
))
1068 return Constant::getNullValue(Ty
);
1072 if (match(Op0
, m_Zero()))
1073 return Constant::getNullValue(Op0
->getType());
1078 return IsDiv
? ConstantInt::get(Ty
, 1) : Constant::getNullValue(Ty
);
1080 KnownBits Known
= computeKnownBits(Op1
, /* Depth */ 0, Q
);
1083 // If the divisor is known to be zero, just return poison. This can happen in
1084 // some cases where its provable indirectly the denominator is zero but it's
1085 // not trivially simplifiable (i.e known zero through a phi node).
1087 return PoisonValue::get(Ty
);
1091 // If the divisor can only be zero or one, we can't have division-by-zero
1092 // or remainder-by-zero, so assume the divisor is 1.
1093 // e.g. 1, zext (i8 X), sdiv X (Y and 1)
1094 if (Known
.countMinLeadingZeros() == Known
.getBitWidth() - 1)
1095 return IsDiv
? Op0
: Constant::getNullValue(Ty
);
1097 // If X * Y does not overflow, then:
1101 if (match(Op0
, m_c_Mul(m_Value(X
), m_Specific(Op1
)))) {
1102 auto *Mul
= cast
<OverflowingBinaryOperator
>(Op0
);
1103 // The multiplication can't overflow if it is defined not to, or if
1104 // X == A / Y for some A.
1105 if ((IsSigned
&& Q
.IIQ
.hasNoSignedWrap(Mul
)) ||
1106 (!IsSigned
&& Q
.IIQ
.hasNoUnsignedWrap(Mul
)) ||
1107 (IsSigned
&& match(X
, m_SDiv(m_Value(), m_Specific(Op1
)))) ||
1108 (!IsSigned
&& match(X
, m_UDiv(m_Value(), m_Specific(Op1
))))) {
1109 return IsDiv
? X
: Constant::getNullValue(Op0
->getType());
1113 if (isDivZero(Op0
, Op1
, Q
, MaxRecurse
, IsSigned
))
1114 return IsDiv
? Constant::getNullValue(Op0
->getType()) : Op0
;
1116 if (Value
*V
= simplifyByDomEq(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1119 // If the operation is with the result of a select instruction, check whether
1120 // operating on either branch of the select always yields the same value.
1121 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
))
1122 if (Value
*V
= threadBinOpOverSelect(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1125 // If the operation is with the result of a phi instruction, check whether
1126 // operating on all incoming values of the phi always yields the same value.
1127 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
1128 if (Value
*V
= threadBinOpOverPHI(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1134 /// These are simplifications common to SDiv and UDiv.
1135 static Value
*simplifyDiv(Instruction::BinaryOps Opcode
, Value
*Op0
, Value
*Op1
,
1136 bool IsExact
, const SimplifyQuery
&Q
,
1137 unsigned MaxRecurse
) {
1138 if (Constant
*C
= foldOrCommuteConstant(Opcode
, Op0
, Op1
, Q
))
1141 if (Value
*V
= simplifyDivRem(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1145 if (IsExact
&& match(Op1
, m_APInt(DivC
))) {
1146 // If this is an exact divide by a constant, then the dividend (Op0) must
1147 // have at least as many trailing zeros as the divisor to divide evenly. If
1148 // it has less trailing zeros, then the result must be poison.
1149 if (DivC
->countr_zero()) {
1150 KnownBits KnownOp0
= computeKnownBits(Op0
, /* Depth */ 0, Q
);
1151 if (KnownOp0
.countMaxTrailingZeros() < DivC
->countr_zero())
1152 return PoisonValue::get(Op0
->getType());
1155 // udiv exact (mul nsw X, C), C --> X
1156 // sdiv exact (mul nuw X, C), C --> X
1157 // where C is not a power of 2.
1159 if (!DivC
->isPowerOf2() &&
1160 (Opcode
== Instruction::UDiv
1161 ? match(Op0
, m_NSWMul(m_Value(X
), m_Specific(Op1
)))
1162 : match(Op0
, m_NUWMul(m_Value(X
), m_Specific(Op1
)))))
1169 /// These are simplifications common to SRem and URem.
1170 static Value
*simplifyRem(Instruction::BinaryOps Opcode
, Value
*Op0
, Value
*Op1
,
1171 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1172 if (Constant
*C
= foldOrCommuteConstant(Opcode
, Op0
, Op1
, Q
))
1175 if (Value
*V
= simplifyDivRem(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1178 // (X << Y) % X -> 0
1179 if (Q
.IIQ
.UseInstrInfo
) {
1180 if ((Opcode
== Instruction::SRem
&&
1181 match(Op0
, m_NSWShl(m_Specific(Op1
), m_Value()))) ||
1182 (Opcode
== Instruction::URem
&&
1183 match(Op0
, m_NUWShl(m_Specific(Op1
), m_Value()))))
1184 return Constant::getNullValue(Op0
->getType());
1187 if (match(Op1
, m_APInt(C0
))) {
1188 // (srem (mul nsw X, C1), C0) -> 0 if C1 s% C0 == 0
1189 // (urem (mul nuw X, C1), C0) -> 0 if C1 u% C0 == 0
1190 if (Opcode
== Instruction::SRem
1192 m_NSWMul(m_Value(), m_CheckedInt([C0
](const APInt
&C
) {
1193 return C
.srem(*C0
).isZero();
1196 m_NUWMul(m_Value(), m_CheckedInt([C0
](const APInt
&C
) {
1197 return C
.urem(*C0
).isZero();
1199 return Constant::getNullValue(Op0
->getType());
1205 /// Given operands for an SDiv, see if we can fold the result.
1206 /// If not, this returns null.
1207 static Value
*simplifySDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1208 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1209 // If two operands are negated and no signed overflow, return -1.
1210 if (isKnownNegation(Op0
, Op1
, /*NeedNSW=*/true))
1211 return Constant::getAllOnesValue(Op0
->getType());
1213 return simplifyDiv(Instruction::SDiv
, Op0
, Op1
, IsExact
, Q
, MaxRecurse
);
1216 Value
*llvm::simplifySDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1217 const SimplifyQuery
&Q
) {
1218 return ::simplifySDivInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1221 /// Given operands for a UDiv, see if we can fold the result.
1222 /// If not, this returns null.
1223 static Value
*simplifyUDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1224 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1225 return simplifyDiv(Instruction::UDiv
, Op0
, Op1
, IsExact
, Q
, MaxRecurse
);
1228 Value
*llvm::simplifyUDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1229 const SimplifyQuery
&Q
) {
1230 return ::simplifyUDivInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1233 /// Given operands for an SRem, see if we can fold the result.
1234 /// If not, this returns null.
1235 static Value
*simplifySRemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
1236 unsigned MaxRecurse
) {
1237 // If the divisor is 0, the result is undefined, so assume the divisor is -1.
1238 // srem Op0, (sext i1 X) --> srem Op0, -1 --> 0
1240 if (match(Op1
, m_SExt(m_Value(X
))) && X
->getType()->isIntOrIntVectorTy(1))
1241 return ConstantInt::getNullValue(Op0
->getType());
1243 // If the two operands are negated, return 0.
1244 if (isKnownNegation(Op0
, Op1
))
1245 return ConstantInt::getNullValue(Op0
->getType());
1247 return simplifyRem(Instruction::SRem
, Op0
, Op1
, Q
, MaxRecurse
);
1250 Value
*llvm::simplifySRemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
1251 return ::simplifySRemInst(Op0
, Op1
, Q
, RecursionLimit
);
1254 /// Given operands for a URem, see if we can fold the result.
1255 /// If not, this returns null.
1256 static Value
*simplifyURemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
1257 unsigned MaxRecurse
) {
1258 return simplifyRem(Instruction::URem
, Op0
, Op1
, Q
, MaxRecurse
);
1261 Value
*llvm::simplifyURemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
1262 return ::simplifyURemInst(Op0
, Op1
, Q
, RecursionLimit
);
1265 /// Returns true if a shift by \c Amount always yields poison.
1266 static bool isPoisonShift(Value
*Amount
, const SimplifyQuery
&Q
) {
1267 Constant
*C
= dyn_cast
<Constant
>(Amount
);
1271 // X shift by undef -> poison because it may shift by the bitwidth.
1272 if (Q
.isUndefValue(C
))
1275 // Shifting by the bitwidth or more is poison. This covers scalars and
1276 // fixed/scalable vectors with splat constants.
1277 const APInt
*AmountC
;
1278 if (match(C
, m_APInt(AmountC
)) && AmountC
->uge(AmountC
->getBitWidth()))
1281 // Try harder for fixed-length vectors:
1282 // If all lanes of a vector shift are poison, the whole shift is poison.
1283 if (isa
<ConstantVector
>(C
) || isa
<ConstantDataVector
>(C
)) {
1284 for (unsigned I
= 0,
1285 E
= cast
<FixedVectorType
>(C
->getType())->getNumElements();
1287 if (!isPoisonShift(C
->getAggregateElement(I
), Q
))
1295 /// Given operands for an Shl, LShr or AShr, see if we can fold the result.
1296 /// If not, this returns null.
1297 static Value
*simplifyShift(Instruction::BinaryOps Opcode
, Value
*Op0
,
1298 Value
*Op1
, bool IsNSW
, const SimplifyQuery
&Q
,
1299 unsigned MaxRecurse
) {
1300 if (Constant
*C
= foldOrCommuteConstant(Opcode
, Op0
, Op1
, Q
))
1303 // poison shift by X -> poison
1304 if (isa
<PoisonValue
>(Op0
))
1307 // 0 shift by X -> 0
1308 if (match(Op0
, m_Zero()))
1309 return Constant::getNullValue(Op0
->getType());
1311 // X shift by 0 -> X
1312 // Shift-by-sign-extended bool must be shift-by-0 because shift-by-all-ones
1315 if (match(Op1
, m_Zero()) ||
1316 (match(Op1
, m_SExt(m_Value(X
))) && X
->getType()->isIntOrIntVectorTy(1)))
1319 // Fold undefined shifts.
1320 if (isPoisonShift(Op1
, Q
))
1321 return PoisonValue::get(Op0
->getType());
1323 // If the operation is with the result of a select instruction, check whether
1324 // operating on either branch of the select always yields the same value.
1325 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
))
1326 if (Value
*V
= threadBinOpOverSelect(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1329 // If the operation is with the result of a phi instruction, check whether
1330 // operating on all incoming values of the phi always yields the same value.
1331 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
1332 if (Value
*V
= threadBinOpOverPHI(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1335 // If any bits in the shift amount make that value greater than or equal to
1336 // the number of bits in the type, the shift is undefined.
1337 KnownBits KnownAmt
= computeKnownBits(Op1
, /* Depth */ 0, Q
);
1338 if (KnownAmt
.getMinValue().uge(KnownAmt
.getBitWidth()))
1339 return PoisonValue::get(Op0
->getType());
1341 // If all valid bits in the shift amount are known zero, the first operand is
1343 unsigned NumValidShiftBits
= Log2_32_Ceil(KnownAmt
.getBitWidth());
1344 if (KnownAmt
.countMinTrailingZeros() >= NumValidShiftBits
)
1347 // Check for nsw shl leading to a poison value.
1349 assert(Opcode
== Instruction::Shl
&& "Expected shl for nsw instruction");
1350 KnownBits KnownVal
= computeKnownBits(Op0
, /* Depth */ 0, Q
);
1351 KnownBits KnownShl
= KnownBits::shl(KnownVal
, KnownAmt
);
1353 if (KnownVal
.Zero
.isSignBitSet())
1354 KnownShl
.Zero
.setSignBit();
1355 if (KnownVal
.One
.isSignBitSet())
1356 KnownShl
.One
.setSignBit();
1358 if (KnownShl
.hasConflict())
1359 return PoisonValue::get(Op0
->getType());
1365 /// Given operands for an LShr or AShr, see if we can fold the result. If not,
1366 /// this returns null.
1367 static Value
*simplifyRightShift(Instruction::BinaryOps Opcode
, Value
*Op0
,
1368 Value
*Op1
, bool IsExact
,
1369 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1371 simplifyShift(Opcode
, Op0
, Op1
, /*IsNSW*/ false, Q
, MaxRecurse
))
1376 return Constant::getNullValue(Op0
->getType());
1379 // undef >> X -> undef (if it's exact)
1380 if (Q
.isUndefValue(Op0
))
1381 return IsExact
? Op0
: Constant::getNullValue(Op0
->getType());
1383 // The low bit cannot be shifted out of an exact shift if it is set.
1384 // TODO: Generalize by counting trailing zeros (see fold for exact division).
1386 KnownBits Op0Known
= computeKnownBits(Op0
, /* Depth */ 0, Q
);
1387 if (Op0Known
.One
[0])
1394 /// Given operands for an Shl, see if we can fold the result.
1395 /// If not, this returns null.
1396 static Value
*simplifyShlInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
1397 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1399 simplifyShift(Instruction::Shl
, Op0
, Op1
, IsNSW
, Q
, MaxRecurse
))
1402 Type
*Ty
= Op0
->getType();
1404 // undef << X -> undef if (if it's NSW/NUW)
1405 if (Q
.isUndefValue(Op0
))
1406 return IsNSW
|| IsNUW
? Op0
: Constant::getNullValue(Ty
);
1408 // (X >> A) << A -> X
1410 if (Q
.IIQ
.UseInstrInfo
&&
1411 match(Op0
, m_Exact(m_Shr(m_Value(X
), m_Specific(Op1
)))))
1414 // shl nuw i8 C, %x -> C iff C has sign bit set.
1415 if (IsNUW
&& match(Op0
, m_Negative()))
1417 // NOTE: could use computeKnownBits() / LazyValueInfo,
1418 // but the cost-benefit analysis suggests it isn't worth it.
1420 // "nuw" guarantees that only zeros are shifted out, and "nsw" guarantees
1421 // that the sign-bit does not change, so the only input that does not
1422 // produce poison is 0, and "0 << (bitwidth-1) --> 0".
1423 if (IsNSW
&& IsNUW
&&
1424 match(Op1
, m_SpecificInt(Ty
->getScalarSizeInBits() - 1)))
1425 return Constant::getNullValue(Ty
);
1430 Value
*llvm::simplifyShlInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
1431 const SimplifyQuery
&Q
) {
1432 return ::simplifyShlInst(Op0
, Op1
, IsNSW
, IsNUW
, Q
, RecursionLimit
);
1435 /// Given operands for an LShr, see if we can fold the result.
1436 /// If not, this returns null.
1437 static Value
*simplifyLShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1438 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1439 if (Value
*V
= simplifyRightShift(Instruction::LShr
, Op0
, Op1
, IsExact
, Q
,
1443 // (X << A) >> A -> X
1445 if (Q
.IIQ
.UseInstrInfo
&& match(Op0
, m_NUWShl(m_Value(X
), m_Specific(Op1
))))
1448 // ((X << A) | Y) >> A -> X if effective width of Y is not larger than A.
1449 // We can return X as we do in the above case since OR alters no bits in X.
1450 // SimplifyDemandedBits in InstCombine can do more general optimization for
1451 // bit manipulation. This pattern aims to provide opportunities for other
1452 // optimizers by supporting a simple but common case in InstSimplify.
1454 const APInt
*ShRAmt
, *ShLAmt
;
1455 if (Q
.IIQ
.UseInstrInfo
&& match(Op1
, m_APInt(ShRAmt
)) &&
1456 match(Op0
, m_c_Or(m_NUWShl(m_Value(X
), m_APInt(ShLAmt
)), m_Value(Y
))) &&
1457 *ShRAmt
== *ShLAmt
) {
1458 const KnownBits YKnown
= computeKnownBits(Y
, /* Depth */ 0, Q
);
1459 const unsigned EffWidthY
= YKnown
.countMaxActiveBits();
1460 if (ShRAmt
->uge(EffWidthY
))
1467 Value
*llvm::simplifyLShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1468 const SimplifyQuery
&Q
) {
1469 return ::simplifyLShrInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1472 /// Given operands for an AShr, see if we can fold the result.
1473 /// If not, this returns null.
1474 static Value
*simplifyAShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1475 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1476 if (Value
*V
= simplifyRightShift(Instruction::AShr
, Op0
, Op1
, IsExact
, Q
,
1481 // (-1 << X) a>> X --> -1
1482 // We could return the original -1 constant to preserve poison elements.
1483 if (match(Op0
, m_AllOnes()) ||
1484 match(Op0
, m_Shl(m_AllOnes(), m_Specific(Op1
))))
1485 return Constant::getAllOnesValue(Op0
->getType());
1487 // (X << A) >> A -> X
1489 if (Q
.IIQ
.UseInstrInfo
&& match(Op0
, m_NSWShl(m_Value(X
), m_Specific(Op1
))))
1492 // Arithmetic shifting an all-sign-bit value is a no-op.
1493 unsigned NumSignBits
= ComputeNumSignBits(Op0
, Q
.DL
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
);
1494 if (NumSignBits
== Op0
->getType()->getScalarSizeInBits())
1500 Value
*llvm::simplifyAShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1501 const SimplifyQuery
&Q
) {
1502 return ::simplifyAShrInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1505 /// Commuted variants are assumed to be handled by calling this function again
1506 /// with the parameters swapped.
1507 static Value
*simplifyUnsignedRangeCheck(ICmpInst
*ZeroICmp
,
1508 ICmpInst
*UnsignedICmp
, bool IsAnd
,
1509 const SimplifyQuery
&Q
) {
1512 CmpPredicate EqPred
;
1513 if (!match(ZeroICmp
, m_ICmp(EqPred
, m_Value(Y
), m_Zero())) ||
1514 !ICmpInst::isEquality(EqPred
))
1517 CmpPredicate UnsignedPred
;
1521 if (match(Y
, m_Sub(m_Value(A
), m_Value(B
)))) {
1522 if (match(UnsignedICmp
,
1523 m_c_ICmp(UnsignedPred
, m_Specific(A
), m_Specific(B
))) &&
1524 ICmpInst::isUnsigned(UnsignedPred
)) {
1525 // A >=/<= B || (A - B) != 0 <--> true
1526 if ((UnsignedPred
== ICmpInst::ICMP_UGE
||
1527 UnsignedPred
== ICmpInst::ICMP_ULE
) &&
1528 EqPred
== ICmpInst::ICMP_NE
&& !IsAnd
)
1529 return ConstantInt::getTrue(UnsignedICmp
->getType());
1530 // A </> B && (A - B) == 0 <--> false
1531 if ((UnsignedPred
== ICmpInst::ICMP_ULT
||
1532 UnsignedPred
== ICmpInst::ICMP_UGT
) &&
1533 EqPred
== ICmpInst::ICMP_EQ
&& IsAnd
)
1534 return ConstantInt::getFalse(UnsignedICmp
->getType());
1536 // A </> B && (A - B) != 0 <--> A </> B
1537 // A </> B || (A - B) != 0 <--> (A - B) != 0
1538 if (EqPred
== ICmpInst::ICMP_NE
&& (UnsignedPred
== ICmpInst::ICMP_ULT
||
1539 UnsignedPred
== ICmpInst::ICMP_UGT
))
1540 return IsAnd
? UnsignedICmp
: ZeroICmp
;
1542 // A <=/>= B && (A - B) == 0 <--> (A - B) == 0
1543 // A <=/>= B || (A - B) == 0 <--> A <=/>= B
1544 if (EqPred
== ICmpInst::ICMP_EQ
&& (UnsignedPred
== ICmpInst::ICMP_ULE
||
1545 UnsignedPred
== ICmpInst::ICMP_UGE
))
1546 return IsAnd
? ZeroICmp
: UnsignedICmp
;
1549 // Given Y = (A - B)
1550 // Y >= A && Y != 0 --> Y >= A iff B != 0
1551 // Y < A || Y == 0 --> Y < A iff B != 0
1552 if (match(UnsignedICmp
,
1553 m_c_ICmp(UnsignedPred
, m_Specific(Y
), m_Specific(A
)))) {
1554 if (UnsignedPred
== ICmpInst::ICMP_UGE
&& IsAnd
&&
1555 EqPred
== ICmpInst::ICMP_NE
&& isKnownNonZero(B
, Q
))
1556 return UnsignedICmp
;
1557 if (UnsignedPred
== ICmpInst::ICMP_ULT
&& !IsAnd
&&
1558 EqPred
== ICmpInst::ICMP_EQ
&& isKnownNonZero(B
, Q
))
1559 return UnsignedICmp
;
1563 if (match(UnsignedICmp
, m_ICmp(UnsignedPred
, m_Value(X
), m_Specific(Y
))) &&
1564 ICmpInst::isUnsigned(UnsignedPred
))
1566 else if (match(UnsignedICmp
,
1567 m_ICmp(UnsignedPred
, m_Specific(Y
), m_Value(X
))) &&
1568 ICmpInst::isUnsigned(UnsignedPred
))
1569 UnsignedPred
= ICmpInst::getSwappedPredicate(UnsignedPred
);
1573 // X > Y && Y == 0 --> Y == 0 iff X != 0
1574 // X > Y || Y == 0 --> X > Y iff X != 0
1575 if (UnsignedPred
== ICmpInst::ICMP_UGT
&& EqPred
== ICmpInst::ICMP_EQ
&&
1576 isKnownNonZero(X
, Q
))
1577 return IsAnd
? ZeroICmp
: UnsignedICmp
;
1579 // X <= Y && Y != 0 --> X <= Y iff X != 0
1580 // X <= Y || Y != 0 --> Y != 0 iff X != 0
1581 if (UnsignedPred
== ICmpInst::ICMP_ULE
&& EqPred
== ICmpInst::ICMP_NE
&&
1582 isKnownNonZero(X
, Q
))
1583 return IsAnd
? UnsignedICmp
: ZeroICmp
;
1585 // The transforms below here are expected to be handled more generally with
1586 // simplifyAndOrOfICmpsWithLimitConst() or in InstCombine's
1587 // foldAndOrOfICmpsWithConstEq(). If we are looking to trim optimizer overlap,
1588 // these are candidates for removal.
1590 // X < Y && Y != 0 --> X < Y
1591 // X < Y || Y != 0 --> Y != 0
1592 if (UnsignedPred
== ICmpInst::ICMP_ULT
&& EqPred
== ICmpInst::ICMP_NE
)
1593 return IsAnd
? UnsignedICmp
: ZeroICmp
;
1595 // X >= Y && Y == 0 --> Y == 0
1596 // X >= Y || Y == 0 --> X >= Y
1597 if (UnsignedPred
== ICmpInst::ICMP_UGE
&& EqPred
== ICmpInst::ICMP_EQ
)
1598 return IsAnd
? ZeroICmp
: UnsignedICmp
;
1600 // X < Y && Y == 0 --> false
1601 if (UnsignedPred
== ICmpInst::ICMP_ULT
&& EqPred
== ICmpInst::ICMP_EQ
&&
1603 return getFalse(UnsignedICmp
->getType());
1605 // X >= Y || Y != 0 --> true
1606 if (UnsignedPred
== ICmpInst::ICMP_UGE
&& EqPred
== ICmpInst::ICMP_NE
&&
1608 return getTrue(UnsignedICmp
->getType());
1613 /// Test if a pair of compares with a shared operand and 2 constants has an
1614 /// empty set intersection, full set union, or if one compare is a superset of
1616 static Value
*simplifyAndOrOfICmpsWithConstants(ICmpInst
*Cmp0
, ICmpInst
*Cmp1
,
1618 // Look for this pattern: {and/or} (icmp X, C0), (icmp X, C1)).
1619 if (Cmp0
->getOperand(0) != Cmp1
->getOperand(0))
1622 const APInt
*C0
, *C1
;
1623 if (!match(Cmp0
->getOperand(1), m_APInt(C0
)) ||
1624 !match(Cmp1
->getOperand(1), m_APInt(C1
)))
1627 auto Range0
= ConstantRange::makeExactICmpRegion(Cmp0
->getPredicate(), *C0
);
1628 auto Range1
= ConstantRange::makeExactICmpRegion(Cmp1
->getPredicate(), *C1
);
1630 // For and-of-compares, check if the intersection is empty:
1631 // (icmp X, C0) && (icmp X, C1) --> empty set --> false
1632 if (IsAnd
&& Range0
.intersectWith(Range1
).isEmptySet())
1633 return getFalse(Cmp0
->getType());
1635 // For or-of-compares, check if the union is full:
1636 // (icmp X, C0) || (icmp X, C1) --> full set --> true
1637 if (!IsAnd
&& Range0
.unionWith(Range1
).isFullSet())
1638 return getTrue(Cmp0
->getType());
1640 // Is one range a superset of the other?
1641 // If this is and-of-compares, take the smaller set:
1642 // (icmp sgt X, 4) && (icmp sgt X, 42) --> icmp sgt X, 42
1643 // If this is or-of-compares, take the larger set:
1644 // (icmp sgt X, 4) || (icmp sgt X, 42) --> icmp sgt X, 4
1645 if (Range0
.contains(Range1
))
1646 return IsAnd
? Cmp1
: Cmp0
;
1647 if (Range1
.contains(Range0
))
1648 return IsAnd
? Cmp0
: Cmp1
;
1653 static Value
*simplifyAndOfICmpsWithAdd(ICmpInst
*Op0
, ICmpInst
*Op1
,
1654 const InstrInfoQuery
&IIQ
) {
1655 // (icmp (add V, C0), C1) & (icmp V, C0)
1656 CmpPredicate Pred0
, Pred1
;
1657 const APInt
*C0
, *C1
;
1659 if (!match(Op0
, m_ICmp(Pred0
, m_Add(m_Value(V
), m_APInt(C0
)), m_APInt(C1
))))
1662 if (!match(Op1
, m_ICmp(Pred1
, m_Specific(V
), m_Value())))
1665 auto *AddInst
= cast
<OverflowingBinaryOperator
>(Op0
->getOperand(0));
1666 if (AddInst
->getOperand(1) != Op1
->getOperand(1))
1669 Type
*ITy
= Op0
->getType();
1670 bool IsNSW
= IIQ
.hasNoSignedWrap(AddInst
);
1671 bool IsNUW
= IIQ
.hasNoUnsignedWrap(AddInst
);
1673 const APInt Delta
= *C1
- *C0
;
1674 if (C0
->isStrictlyPositive()) {
1676 if (Pred0
== ICmpInst::ICMP_ULT
&& Pred1
== ICmpInst::ICMP_SGT
)
1677 return getFalse(ITy
);
1678 if (Pred0
== ICmpInst::ICMP_SLT
&& Pred1
== ICmpInst::ICMP_SGT
&& IsNSW
)
1679 return getFalse(ITy
);
1682 if (Pred0
== ICmpInst::ICMP_ULE
&& Pred1
== ICmpInst::ICMP_SGT
)
1683 return getFalse(ITy
);
1684 if (Pred0
== ICmpInst::ICMP_SLE
&& Pred1
== ICmpInst::ICMP_SGT
&& IsNSW
)
1685 return getFalse(ITy
);
1688 if (C0
->getBoolValue() && IsNUW
) {
1690 if (Pred0
== ICmpInst::ICMP_ULT
&& Pred1
== ICmpInst::ICMP_UGT
)
1691 return getFalse(ITy
);
1693 if (Pred0
== ICmpInst::ICMP_ULE
&& Pred1
== ICmpInst::ICMP_UGT
)
1694 return getFalse(ITy
);
1700 /// Try to simplify and/or of icmp with ctpop intrinsic.
1701 static Value
*simplifyAndOrOfICmpsWithCtpop(ICmpInst
*Cmp0
, ICmpInst
*Cmp1
,
1703 CmpPredicate Pred0
, Pred1
;
1706 if (!match(Cmp0
, m_ICmp(Pred0
, m_Intrinsic
<Intrinsic::ctpop
>(m_Value(X
)),
1708 !match(Cmp1
, m_ICmp(Pred1
, m_Specific(X
), m_ZeroInt())) || C
->isZero())
1711 // (ctpop(X) == C) || (X != 0) --> X != 0 where C > 0
1712 if (!IsAnd
&& Pred0
== ICmpInst::ICMP_EQ
&& Pred1
== ICmpInst::ICMP_NE
)
1714 // (ctpop(X) != C) && (X == 0) --> X == 0 where C > 0
1715 if (IsAnd
&& Pred0
== ICmpInst::ICMP_NE
&& Pred1
== ICmpInst::ICMP_EQ
)
1721 static Value
*simplifyAndOfICmps(ICmpInst
*Op0
, ICmpInst
*Op1
,
1722 const SimplifyQuery
&Q
) {
1723 if (Value
*X
= simplifyUnsignedRangeCheck(Op0
, Op1
, /*IsAnd=*/true, Q
))
1725 if (Value
*X
= simplifyUnsignedRangeCheck(Op1
, Op0
, /*IsAnd=*/true, Q
))
1728 if (Value
*X
= simplifyAndOrOfICmpsWithConstants(Op0
, Op1
, true))
1731 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op0
, Op1
, true))
1733 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op1
, Op0
, true))
1736 if (Value
*X
= simplifyAndOfICmpsWithAdd(Op0
, Op1
, Q
.IIQ
))
1738 if (Value
*X
= simplifyAndOfICmpsWithAdd(Op1
, Op0
, Q
.IIQ
))
1744 static Value
*simplifyOrOfICmpsWithAdd(ICmpInst
*Op0
, ICmpInst
*Op1
,
1745 const InstrInfoQuery
&IIQ
) {
1746 // (icmp (add V, C0), C1) | (icmp V, C0)
1747 CmpPredicate Pred0
, Pred1
;
1748 const APInt
*C0
, *C1
;
1750 if (!match(Op0
, m_ICmp(Pred0
, m_Add(m_Value(V
), m_APInt(C0
)), m_APInt(C1
))))
1753 if (!match(Op1
, m_ICmp(Pred1
, m_Specific(V
), m_Value())))
1756 auto *AddInst
= cast
<BinaryOperator
>(Op0
->getOperand(0));
1757 if (AddInst
->getOperand(1) != Op1
->getOperand(1))
1760 Type
*ITy
= Op0
->getType();
1761 bool IsNSW
= IIQ
.hasNoSignedWrap(AddInst
);
1762 bool IsNUW
= IIQ
.hasNoUnsignedWrap(AddInst
);
1764 const APInt Delta
= *C1
- *C0
;
1765 if (C0
->isStrictlyPositive()) {
1767 if (Pred0
== ICmpInst::ICMP_UGE
&& Pred1
== ICmpInst::ICMP_SLE
)
1768 return getTrue(ITy
);
1769 if (Pred0
== ICmpInst::ICMP_SGE
&& Pred1
== ICmpInst::ICMP_SLE
&& IsNSW
)
1770 return getTrue(ITy
);
1773 if (Pred0
== ICmpInst::ICMP_UGT
&& Pred1
== ICmpInst::ICMP_SLE
)
1774 return getTrue(ITy
);
1775 if (Pred0
== ICmpInst::ICMP_SGT
&& Pred1
== ICmpInst::ICMP_SLE
&& IsNSW
)
1776 return getTrue(ITy
);
1779 if (C0
->getBoolValue() && IsNUW
) {
1781 if (Pred0
== ICmpInst::ICMP_UGE
&& Pred1
== ICmpInst::ICMP_ULE
)
1782 return getTrue(ITy
);
1784 if (Pred0
== ICmpInst::ICMP_UGT
&& Pred1
== ICmpInst::ICMP_ULE
)
1785 return getTrue(ITy
);
1791 static Value
*simplifyOrOfICmps(ICmpInst
*Op0
, ICmpInst
*Op1
,
1792 const SimplifyQuery
&Q
) {
1793 if (Value
*X
= simplifyUnsignedRangeCheck(Op0
, Op1
, /*IsAnd=*/false, Q
))
1795 if (Value
*X
= simplifyUnsignedRangeCheck(Op1
, Op0
, /*IsAnd=*/false, Q
))
1798 if (Value
*X
= simplifyAndOrOfICmpsWithConstants(Op0
, Op1
, false))
1801 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op0
, Op1
, false))
1803 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op1
, Op0
, false))
1806 if (Value
*X
= simplifyOrOfICmpsWithAdd(Op0
, Op1
, Q
.IIQ
))
1808 if (Value
*X
= simplifyOrOfICmpsWithAdd(Op1
, Op0
, Q
.IIQ
))
1814 static Value
*simplifyAndOrOfFCmps(const SimplifyQuery
&Q
, FCmpInst
*LHS
,
1815 FCmpInst
*RHS
, bool IsAnd
) {
1816 Value
*LHS0
= LHS
->getOperand(0), *LHS1
= LHS
->getOperand(1);
1817 Value
*RHS0
= RHS
->getOperand(0), *RHS1
= RHS
->getOperand(1);
1818 if (LHS0
->getType() != RHS0
->getType())
1821 FCmpInst::Predicate PredL
= LHS
->getPredicate(), PredR
= RHS
->getPredicate();
1822 auto AbsOrSelfLHS0
= m_CombineOr(m_Specific(LHS0
), m_FAbs(m_Specific(LHS0
)));
1823 if ((PredL
== FCmpInst::FCMP_ORD
|| PredL
== FCmpInst::FCMP_UNO
) &&
1824 ((FCmpInst::isOrdered(PredR
) && IsAnd
) ||
1825 (FCmpInst::isUnordered(PredR
) && !IsAnd
))) {
1826 // (fcmp ord X, 0) & (fcmp o** X/abs(X), Y) --> fcmp o** X/abs(X), Y
1827 // (fcmp uno X, 0) & (fcmp o** X/abs(X), Y) --> false
1828 // (fcmp uno X, 0) | (fcmp u** X/abs(X), Y) --> fcmp u** X/abs(X), Y
1829 // (fcmp ord X, 0) | (fcmp u** X/abs(X), Y) --> true
1830 if ((match(RHS0
, AbsOrSelfLHS0
) || match(RHS1
, AbsOrSelfLHS0
)) &&
1831 match(LHS1
, m_PosZeroFP()))
1832 return FCmpInst::isOrdered(PredL
) == FCmpInst::isOrdered(PredR
)
1833 ? static_cast<Value
*>(RHS
)
1834 : ConstantInt::getBool(LHS
->getType(), !IsAnd
);
1837 auto AbsOrSelfRHS0
= m_CombineOr(m_Specific(RHS0
), m_FAbs(m_Specific(RHS0
)));
1838 if ((PredR
== FCmpInst::FCMP_ORD
|| PredR
== FCmpInst::FCMP_UNO
) &&
1839 ((FCmpInst::isOrdered(PredL
) && IsAnd
) ||
1840 (FCmpInst::isUnordered(PredL
) && !IsAnd
))) {
1841 // (fcmp o** X/abs(X), Y) & (fcmp ord X, 0) --> fcmp o** X/abs(X), Y
1842 // (fcmp o** X/abs(X), Y) & (fcmp uno X, 0) --> false
1843 // (fcmp u** X/abs(X), Y) | (fcmp uno X, 0) --> fcmp u** X/abs(X), Y
1844 // (fcmp u** X/abs(X), Y) | (fcmp ord X, 0) --> true
1845 if ((match(LHS0
, AbsOrSelfRHS0
) || match(LHS1
, AbsOrSelfRHS0
)) &&
1846 match(RHS1
, m_PosZeroFP()))
1847 return FCmpInst::isOrdered(PredL
) == FCmpInst::isOrdered(PredR
)
1848 ? static_cast<Value
*>(LHS
)
1849 : ConstantInt::getBool(LHS
->getType(), !IsAnd
);
1855 static Value
*simplifyAndOrOfCmps(const SimplifyQuery
&Q
, Value
*Op0
,
1856 Value
*Op1
, bool IsAnd
) {
1857 // Look through casts of the 'and' operands to find compares.
1858 auto *Cast0
= dyn_cast
<CastInst
>(Op0
);
1859 auto *Cast1
= dyn_cast
<CastInst
>(Op1
);
1860 if (Cast0
&& Cast1
&& Cast0
->getOpcode() == Cast1
->getOpcode() &&
1861 Cast0
->getSrcTy() == Cast1
->getSrcTy()) {
1862 Op0
= Cast0
->getOperand(0);
1863 Op1
= Cast1
->getOperand(0);
1867 auto *ICmp0
= dyn_cast
<ICmpInst
>(Op0
);
1868 auto *ICmp1
= dyn_cast
<ICmpInst
>(Op1
);
1870 V
= IsAnd
? simplifyAndOfICmps(ICmp0
, ICmp1
, Q
)
1871 : simplifyOrOfICmps(ICmp0
, ICmp1
, Q
);
1873 auto *FCmp0
= dyn_cast
<FCmpInst
>(Op0
);
1874 auto *FCmp1
= dyn_cast
<FCmpInst
>(Op1
);
1876 V
= simplifyAndOrOfFCmps(Q
, FCmp0
, FCmp1
, IsAnd
);
1883 // If we looked through casts, we can only handle a constant simplification
1884 // because we are not allowed to create a cast instruction here.
1885 if (auto *C
= dyn_cast
<Constant
>(V
))
1886 return ConstantFoldCastOperand(Cast0
->getOpcode(), C
, Cast0
->getType(),
1892 static Value
*simplifyWithOpReplaced(Value
*V
, Value
*Op
, Value
*RepOp
,
1893 const SimplifyQuery
&Q
,
1894 bool AllowRefinement
,
1895 SmallVectorImpl
<Instruction
*> *DropFlags
,
1896 unsigned MaxRecurse
);
1898 static Value
*simplifyAndOrWithICmpEq(unsigned Opcode
, Value
*Op0
, Value
*Op1
,
1899 const SimplifyQuery
&Q
,
1900 unsigned MaxRecurse
) {
1901 assert((Opcode
== Instruction::And
|| Opcode
== Instruction::Or
) &&
1905 if (!match(Op0
, m_ICmp(Pred
, m_Value(A
), m_Value(B
))) ||
1906 !ICmpInst::isEquality(Pred
))
1909 auto Simplify
= [&](Value
*Res
) -> Value
* {
1910 Constant
*Absorber
= ConstantExpr::getBinOpAbsorber(Opcode
, Res
->getType());
1912 // and (icmp eq a, b), x implies (a==b) inside x.
1913 // or (icmp ne a, b), x implies (a==b) inside x.
1914 // If x simplifies to true/false, we can simplify the and/or.
1916 (Opcode
== Instruction::And
? ICmpInst::ICMP_EQ
: ICmpInst::ICMP_NE
)) {
1917 if (Res
== Absorber
)
1919 if (Res
== ConstantExpr::getBinOpIdentity(Opcode
, Res
->getType()))
1924 // If we have and (icmp ne a, b), x and for a==b we can simplify x to false,
1925 // then we can drop the icmp, as x will already be false in the case where
1926 // the icmp is false. Similar for or and true.
1927 if (Res
== Absorber
)
1932 // In the final case (Res == Absorber with inverted predicate), it is safe to
1933 // refine poison during simplification, but not undef. For simplicity always
1934 // disable undef-based folds here.
1935 if (Value
*Res
= simplifyWithOpReplaced(Op1
, A
, B
, Q
.getWithoutUndef(),
1936 /* AllowRefinement */ true,
1937 /* DropFlags */ nullptr, MaxRecurse
))
1938 return Simplify(Res
);
1939 if (Value
*Res
= simplifyWithOpReplaced(Op1
, B
, A
, Q
.getWithoutUndef(),
1940 /* AllowRefinement */ true,
1941 /* DropFlags */ nullptr, MaxRecurse
))
1942 return Simplify(Res
);
1947 /// Given a bitwise logic op, check if the operands are add/sub with a common
1948 /// source value and inverted constant (identity: C - X -> ~(X + ~C)).
1949 static Value
*simplifyLogicOfAddSub(Value
*Op0
, Value
*Op1
,
1950 Instruction::BinaryOps Opcode
) {
1951 assert(Op0
->getType() == Op1
->getType() && "Mismatched binop types");
1952 assert(BinaryOperator::isBitwiseLogicOp(Opcode
) && "Expected logic op");
1955 if ((match(Op0
, m_Add(m_Value(X
), m_Constant(C1
))) &&
1956 match(Op1
, m_Sub(m_Constant(C2
), m_Specific(X
)))) ||
1957 (match(Op1
, m_Add(m_Value(X
), m_Constant(C1
))) &&
1958 match(Op0
, m_Sub(m_Constant(C2
), m_Specific(X
))))) {
1959 if (ConstantExpr::getNot(C1
) == C2
) {
1960 // (X + C) & (~C - X) --> (X + C) & ~(X + C) --> 0
1961 // (X + C) | (~C - X) --> (X + C) | ~(X + C) --> -1
1962 // (X + C) ^ (~C - X) --> (X + C) ^ ~(X + C) --> -1
1963 Type
*Ty
= Op0
->getType();
1964 return Opcode
== Instruction::And
? ConstantInt::getNullValue(Ty
)
1965 : ConstantInt::getAllOnesValue(Ty
);
1971 // Commutative patterns for and that will be tried with both operand orders.
1972 static Value
*simplifyAndCommutative(Value
*Op0
, Value
*Op1
,
1973 const SimplifyQuery
&Q
,
1974 unsigned MaxRecurse
) {
1976 if (match(Op0
, m_Not(m_Specific(Op1
))))
1977 return Constant::getNullValue(Op0
->getType());
1980 if (match(Op0
, m_c_Or(m_Specific(Op1
), m_Value())))
1983 // (X | ~Y) & (X | Y) --> X
1985 if (match(Op0
, m_c_Or(m_Value(X
), m_Not(m_Value(Y
)))) &&
1986 match(Op1
, m_c_Or(m_Specific(X
), m_Specific(Y
))))
1989 // If we have a multiplication overflow check that is being 'and'ed with a
1990 // check that one of the multipliers is not zero, we can omit the 'and', and
1991 // only keep the overflow check.
1992 if (isCheckForZeroAndMulWithOverflow(Op0
, Op1
, true))
1995 // -A & A = A if A is a power of two or zero.
1996 if (match(Op0
, m_Neg(m_Specific(Op1
))) &&
1997 isKnownToBeAPowerOfTwo(Op1
, Q
.DL
, /*OrZero*/ true, 0, Q
.AC
, Q
.CxtI
, Q
.DT
))
2000 // This is a similar pattern used for checking if a value is a power-of-2:
2001 // (A - 1) & A --> 0 (if A is a power-of-2 or 0)
2002 if (match(Op0
, m_Add(m_Specific(Op1
), m_AllOnes())) &&
2003 isKnownToBeAPowerOfTwo(Op1
, Q
.DL
, /*OrZero*/ true, 0, Q
.AC
, Q
.CxtI
, Q
.DT
))
2004 return Constant::getNullValue(Op1
->getType());
2006 // (x << N) & ((x << M) - 1) --> 0, where x is known to be a power of 2 and
2008 const APInt
*Shift1
, *Shift2
;
2009 if (match(Op0
, m_Shl(m_Value(X
), m_APInt(Shift1
))) &&
2010 match(Op1
, m_Add(m_Shl(m_Specific(X
), m_APInt(Shift2
)), m_AllOnes())) &&
2011 isKnownToBeAPowerOfTwo(X
, Q
.DL
, /*OrZero*/ true, /*Depth*/ 0, Q
.AC
,
2013 Shift1
->uge(*Shift2
))
2014 return Constant::getNullValue(Op0
->getType());
2017 simplifyAndOrWithICmpEq(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2023 /// Given operands for an And, see if we can fold the result.
2024 /// If not, this returns null.
2025 static Value
*simplifyAndInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
2026 unsigned MaxRecurse
) {
2027 if (Constant
*C
= foldOrCommuteConstant(Instruction::And
, Op0
, Op1
, Q
))
2030 // X & poison -> poison
2031 if (isa
<PoisonValue
>(Op1
))
2035 if (Q
.isUndefValue(Op1
))
2036 return Constant::getNullValue(Op0
->getType());
2043 if (match(Op1
, m_Zero()))
2044 return Constant::getNullValue(Op0
->getType());
2047 if (match(Op1
, m_AllOnes()))
2050 if (Value
*Res
= simplifyAndCommutative(Op0
, Op1
, Q
, MaxRecurse
))
2052 if (Value
*Res
= simplifyAndCommutative(Op1
, Op0
, Q
, MaxRecurse
))
2055 if (Value
*V
= simplifyLogicOfAddSub(Op0
, Op1
, Instruction::And
))
2058 // A mask that only clears known zeros of a shifted value is a no-op.
2062 if (match(Op1
, m_APInt(Mask
))) {
2063 // If all bits in the inverted and shifted mask are clear:
2064 // and (shl X, ShAmt), Mask --> shl X, ShAmt
2065 if (match(Op0
, m_Shl(m_Value(X
), m_APInt(ShAmt
))) &&
2066 (~(*Mask
)).lshr(*ShAmt
).isZero())
2069 // If all bits in the inverted and shifted mask are clear:
2070 // and (lshr X, ShAmt), Mask --> lshr X, ShAmt
2071 if (match(Op0
, m_LShr(m_Value(X
), m_APInt(ShAmt
))) &&
2072 (~(*Mask
)).shl(*ShAmt
).isZero())
2076 // and 2^x-1, 2^C --> 0 where x <= C.
2077 const APInt
*PowerC
;
2079 if (match(Op1
, m_Power2(PowerC
)) &&
2080 match(Op0
, m_Add(m_Value(Shift
), m_AllOnes())) &&
2081 isKnownToBeAPowerOfTwo(Shift
, Q
.DL
, /*OrZero*/ false, 0, Q
.AC
, Q
.CxtI
,
2083 KnownBits Known
= computeKnownBits(Shift
, /* Depth */ 0, Q
);
2084 // Use getActiveBits() to make use of the additional power of two knowledge
2085 if (PowerC
->getActiveBits() >= Known
.getMaxValue().getActiveBits())
2086 return ConstantInt::getNullValue(Op1
->getType());
2089 if (Value
*V
= simplifyAndOrOfCmps(Q
, Op0
, Op1
, true))
2092 // Try some generic simplifications for associative operations.
2094 simplifyAssociativeBinOp(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2097 // And distributes over Or. Try some generic simplifications based on this.
2098 if (Value
*V
= expandCommutativeBinOp(Instruction::And
, Op0
, Op1
,
2099 Instruction::Or
, Q
, MaxRecurse
))
2102 // And distributes over Xor. Try some generic simplifications based on this.
2103 if (Value
*V
= expandCommutativeBinOp(Instruction::And
, Op0
, Op1
,
2104 Instruction::Xor
, Q
, MaxRecurse
))
2107 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
)) {
2108 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2109 // A & (A && B) -> A && B
2110 if (match(Op1
, m_Select(m_Specific(Op0
), m_Value(), m_Zero())))
2112 else if (match(Op0
, m_Select(m_Specific(Op1
), m_Value(), m_Zero())))
2115 // If the operation is with the result of a select instruction, check
2116 // whether operating on either branch of the select always yields the same
2119 threadBinOpOverSelect(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2123 // If the operation is with the result of a phi instruction, check whether
2124 // operating on all incoming values of the phi always yields the same value.
2125 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
2127 threadBinOpOverPHI(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2130 // Assuming the effective width of Y is not larger than A, i.e. all bits
2131 // from X and Y are disjoint in (X << A) | Y,
2132 // if the mask of this AND op covers all bits of X or Y, while it covers
2133 // no bits from the other, we can bypass this AND op. E.g.,
2134 // ((X << A) | Y) & Mask -> Y,
2135 // if Mask = ((1 << effective_width_of(Y)) - 1)
2136 // ((X << A) | Y) & Mask -> X << A,
2137 // if Mask = ((1 << effective_width_of(X)) - 1) << A
2138 // SimplifyDemandedBits in InstCombine can optimize the general case.
2139 // This pattern aims to help other passes for a common case.
2141 if (Q
.IIQ
.UseInstrInfo
&& match(Op1
, m_APInt(Mask
)) &&
2142 match(Op0
, m_c_Or(m_CombineAnd(m_NUWShl(m_Value(X
), m_APInt(ShAmt
)),
2145 const unsigned Width
= Op0
->getType()->getScalarSizeInBits();
2146 const unsigned ShftCnt
= ShAmt
->getLimitedValue(Width
);
2147 const KnownBits YKnown
= computeKnownBits(Y
, /* Depth */ 0, Q
);
2148 const unsigned EffWidthY
= YKnown
.countMaxActiveBits();
2149 if (EffWidthY
<= ShftCnt
) {
2150 const KnownBits XKnown
= computeKnownBits(X
, /* Depth */ 0, Q
);
2151 const unsigned EffWidthX
= XKnown
.countMaxActiveBits();
2152 const APInt EffBitsY
= APInt::getLowBitsSet(Width
, EffWidthY
);
2153 const APInt EffBitsX
= APInt::getLowBitsSet(Width
, EffWidthX
) << ShftCnt
;
2154 // If the mask is extracting all bits from X or Y as is, we can skip
2156 if (EffBitsY
.isSubsetOf(*Mask
) && !EffBitsX
.intersects(*Mask
))
2158 if (EffBitsX
.isSubsetOf(*Mask
) && !EffBitsY
.intersects(*Mask
))
2163 // ((X | Y) ^ X ) & ((X | Y) ^ Y) --> 0
2164 // ((X | Y) ^ Y ) & ((X | Y) ^ X) --> 0
2166 if (match(Op0
, m_c_Xor(m_Value(X
),
2167 m_CombineAnd(m_BinOp(Or
),
2168 m_c_Or(m_Deferred(X
), m_Value(Y
))))) &&
2169 match(Op1
, m_c_Xor(m_Specific(Or
), m_Specific(Y
))))
2170 return Constant::getNullValue(Op0
->getType());
2174 // (A ^ C) & (A ^ ~C) -> 0
2175 if (match(Op0
, m_Xor(m_Value(A
), m_APInt(C1
))) &&
2176 match(Op1
, m_Xor(m_Specific(A
), m_SpecificInt(~*C1
))))
2177 return Constant::getNullValue(Op0
->getType());
2179 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2180 if (std::optional
<bool> Implied
= isImpliedCondition(Op0
, Op1
, Q
.DL
)) {
2181 // If Op0 is true implies Op1 is true, then Op0 is a subset of Op1.
2182 if (*Implied
== true)
2184 // If Op0 is true implies Op1 is false, then they are not true together.
2185 if (*Implied
== false)
2186 return ConstantInt::getFalse(Op0
->getType());
2188 if (std::optional
<bool> Implied
= isImpliedCondition(Op1
, Op0
, Q
.DL
)) {
2189 // If Op1 is true implies Op0 is true, then Op1 is a subset of Op0.
2192 // If Op1 is true implies Op0 is false, then they are not true together.
2194 return ConstantInt::getFalse(Op1
->getType());
2198 if (Value
*V
= simplifyByDomEq(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2204 Value
*llvm::simplifyAndInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
2205 return ::simplifyAndInst(Op0
, Op1
, Q
, RecursionLimit
);
2208 // TODO: Many of these folds could use LogicalAnd/LogicalOr.
2209 static Value
*simplifyOrLogic(Value
*X
, Value
*Y
) {
2210 assert(X
->getType() == Y
->getType() && "Expected same type for 'or' ops");
2211 Type
*Ty
= X
->getType();
2214 if (match(Y
, m_Not(m_Specific(X
))))
2215 return ConstantInt::getAllOnesValue(Ty
);
2217 // X | ~(X & ?) = -1
2218 if (match(Y
, m_Not(m_c_And(m_Specific(X
), m_Value()))))
2219 return ConstantInt::getAllOnesValue(Ty
);
2221 // X | (X & ?) --> X
2222 if (match(Y
, m_c_And(m_Specific(X
), m_Value())))
2227 // (A ^ B) | (A | B) --> A | B
2228 // (A ^ B) | (B | A) --> B | A
2229 if (match(X
, m_Xor(m_Value(A
), m_Value(B
))) &&
2230 match(Y
, m_c_Or(m_Specific(A
), m_Specific(B
))))
2233 // ~(A ^ B) | (A | B) --> -1
2234 // ~(A ^ B) | (B | A) --> -1
2235 if (match(X
, m_Not(m_Xor(m_Value(A
), m_Value(B
)))) &&
2236 match(Y
, m_c_Or(m_Specific(A
), m_Specific(B
))))
2237 return ConstantInt::getAllOnesValue(Ty
);
2239 // (A & ~B) | (A ^ B) --> A ^ B
2240 // (~B & A) | (A ^ B) --> A ^ B
2241 // (A & ~B) | (B ^ A) --> B ^ A
2242 // (~B & A) | (B ^ A) --> B ^ A
2243 if (match(X
, m_c_And(m_Value(A
), m_Not(m_Value(B
)))) &&
2244 match(Y
, m_c_Xor(m_Specific(A
), m_Specific(B
))))
2247 // (~A ^ B) | (A & B) --> ~A ^ B
2248 // (B ^ ~A) | (A & B) --> B ^ ~A
2249 // (~A ^ B) | (B & A) --> ~A ^ B
2250 // (B ^ ~A) | (B & A) --> B ^ ~A
2251 if (match(X
, m_c_Xor(m_Not(m_Value(A
)), m_Value(B
))) &&
2252 match(Y
, m_c_And(m_Specific(A
), m_Specific(B
))))
2255 // (~A | B) | (A ^ B) --> -1
2256 // (~A | B) | (B ^ A) --> -1
2257 // (B | ~A) | (A ^ B) --> -1
2258 // (B | ~A) | (B ^ A) --> -1
2259 if (match(X
, m_c_Or(m_Not(m_Value(A
)), m_Value(B
))) &&
2260 match(Y
, m_c_Xor(m_Specific(A
), m_Specific(B
))))
2261 return ConstantInt::getAllOnesValue(Ty
);
2263 // (~A & B) | ~(A | B) --> ~A
2264 // (~A & B) | ~(B | A) --> ~A
2265 // (B & ~A) | ~(A | B) --> ~A
2266 // (B & ~A) | ~(B | A) --> ~A
2268 if (match(X
, m_c_And(m_CombineAnd(m_Value(NotA
), m_Not(m_Value(A
))),
2270 match(Y
, m_Not(m_c_Or(m_Specific(A
), m_Specific(B
)))))
2272 // The same is true of Logical And
2273 // TODO: This could share the logic of the version above if there was a
2274 // version of LogicalAnd that allowed more than just i1 types.
2275 if (match(X
, m_c_LogicalAnd(m_CombineAnd(m_Value(NotA
), m_Not(m_Value(A
))),
2277 match(Y
, m_Not(m_c_LogicalOr(m_Specific(A
), m_Specific(B
)))))
2280 // ~(A ^ B) | (A & B) --> ~(A ^ B)
2281 // ~(A ^ B) | (B & A) --> ~(A ^ B)
2283 if (match(X
, m_CombineAnd(m_Not(m_Xor(m_Value(A
), m_Value(B
))),
2285 match(Y
, m_c_And(m_Specific(A
), m_Specific(B
))))
2288 // ~(A & B) | (A ^ B) --> ~(A & B)
2289 // ~(A & B) | (B ^ A) --> ~(A & B)
2290 if (match(X
, m_CombineAnd(m_Not(m_And(m_Value(A
), m_Value(B
))),
2292 match(Y
, m_c_Xor(m_Specific(A
), m_Specific(B
))))
2298 /// Given operands for an Or, see if we can fold the result.
2299 /// If not, this returns null.
2300 static Value
*simplifyOrInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
2301 unsigned MaxRecurse
) {
2302 if (Constant
*C
= foldOrCommuteConstant(Instruction::Or
, Op0
, Op1
, Q
))
2305 // X | poison -> poison
2306 if (isa
<PoisonValue
>(Op1
))
2311 // Do not return Op1 because it may contain undef elements if it's a vector.
2312 if (Q
.isUndefValue(Op1
) || match(Op1
, m_AllOnes()))
2313 return Constant::getAllOnesValue(Op0
->getType());
2317 if (Op0
== Op1
|| match(Op1
, m_Zero()))
2320 if (Value
*R
= simplifyOrLogic(Op0
, Op1
))
2322 if (Value
*R
= simplifyOrLogic(Op1
, Op0
))
2325 if (Value
*V
= simplifyLogicOfAddSub(Op0
, Op1
, Instruction::Or
))
2328 // Rotated -1 is still -1:
2329 // (-1 << X) | (-1 >> (C - X)) --> -1
2330 // (-1 >> X) | (-1 << (C - X)) --> -1
2331 // ...with C <= bitwidth (and commuted variants).
2333 if ((match(Op0
, m_Shl(m_AllOnes(), m_Value(X
))) &&
2334 match(Op1
, m_LShr(m_AllOnes(), m_Value(Y
)))) ||
2335 (match(Op1
, m_Shl(m_AllOnes(), m_Value(X
))) &&
2336 match(Op0
, m_LShr(m_AllOnes(), m_Value(Y
))))) {
2338 if ((match(X
, m_Sub(m_APInt(C
), m_Specific(Y
))) ||
2339 match(Y
, m_Sub(m_APInt(C
), m_Specific(X
)))) &&
2340 C
->ule(X
->getType()->getScalarSizeInBits())) {
2341 return ConstantInt::getAllOnesValue(X
->getType());
2345 // A funnel shift (rotate) can be decomposed into simpler shifts. See if we
2346 // are mixing in another shift that is redundant with the funnel shift.
2348 // (fshl X, ?, Y) | (shl X, Y) --> fshl X, ?, Y
2349 // (shl X, Y) | (fshl X, ?, Y) --> fshl X, ?, Y
2351 m_Intrinsic
<Intrinsic::fshl
>(m_Value(X
), m_Value(), m_Value(Y
))) &&
2352 match(Op1
, m_Shl(m_Specific(X
), m_Specific(Y
))))
2355 m_Intrinsic
<Intrinsic::fshl
>(m_Value(X
), m_Value(), m_Value(Y
))) &&
2356 match(Op0
, m_Shl(m_Specific(X
), m_Specific(Y
))))
2359 // (fshr ?, X, Y) | (lshr X, Y) --> fshr ?, X, Y
2360 // (lshr X, Y) | (fshr ?, X, Y) --> fshr ?, X, Y
2362 m_Intrinsic
<Intrinsic::fshr
>(m_Value(), m_Value(X
), m_Value(Y
))) &&
2363 match(Op1
, m_LShr(m_Specific(X
), m_Specific(Y
))))
2366 m_Intrinsic
<Intrinsic::fshr
>(m_Value(), m_Value(X
), m_Value(Y
))) &&
2367 match(Op0
, m_LShr(m_Specific(X
), m_Specific(Y
))))
2371 simplifyAndOrWithICmpEq(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2374 simplifyAndOrWithICmpEq(Instruction::Or
, Op1
, Op0
, Q
, MaxRecurse
))
2377 if (Value
*V
= simplifyAndOrOfCmps(Q
, Op0
, Op1
, false))
2380 // If we have a multiplication overflow check that is being 'and'ed with a
2381 // check that one of the multipliers is not zero, we can omit the 'and', and
2382 // only keep the overflow check.
2383 if (isCheckForZeroAndMulWithOverflow(Op0
, Op1
, false))
2385 if (isCheckForZeroAndMulWithOverflow(Op1
, Op0
, false))
2388 // Try some generic simplifications for associative operations.
2390 simplifyAssociativeBinOp(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2393 // Or distributes over And. Try some generic simplifications based on this.
2394 if (Value
*V
= expandCommutativeBinOp(Instruction::Or
, Op0
, Op1
,
2395 Instruction::And
, Q
, MaxRecurse
))
2398 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
)) {
2399 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2400 // A | (A || B) -> A || B
2401 if (match(Op1
, m_Select(m_Specific(Op0
), m_One(), m_Value())))
2403 else if (match(Op0
, m_Select(m_Specific(Op1
), m_One(), m_Value())))
2406 // If the operation is with the result of a select instruction, check
2407 // whether operating on either branch of the select always yields the same
2410 threadBinOpOverSelect(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2414 // (A & C1)|(B & C2)
2416 const APInt
*C1
, *C2
;
2417 if (match(Op0
, m_And(m_Value(A
), m_APInt(C1
))) &&
2418 match(Op1
, m_And(m_Value(B
), m_APInt(C2
)))) {
2420 // (A & C1)|(B & C2)
2421 // If we have: ((V + N) & C1) | (V & C2)
2422 // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
2423 // replace with V+N.
2425 if (C2
->isMask() && // C2 == 0+1+
2426 match(A
, m_c_Add(m_Specific(B
), m_Value(N
)))) {
2427 // Add commutes, try both ways.
2428 if (MaskedValueIsZero(N
, *C2
, Q
))
2431 // Or commutes, try both ways.
2432 if (C1
->isMask() && match(B
, m_c_Add(m_Specific(A
), m_Value(N
)))) {
2433 // Add commutes, try both ways.
2434 if (MaskedValueIsZero(N
, *C1
, Q
))
2440 // If the operation is with the result of a phi instruction, check whether
2441 // operating on all incoming values of the phi always yields the same value.
2442 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
2443 if (Value
*V
= threadBinOpOverPHI(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2446 // (A ^ C) | (A ^ ~C) -> -1, i.e. all bits set to one.
2447 if (match(Op0
, m_Xor(m_Value(A
), m_APInt(C1
))) &&
2448 match(Op1
, m_Xor(m_Specific(A
), m_SpecificInt(~*C1
))))
2449 return Constant::getAllOnesValue(Op0
->getType());
2451 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2452 if (std::optional
<bool> Implied
=
2453 isImpliedCondition(Op0
, Op1
, Q
.DL
, false)) {
2454 // If Op0 is false implies Op1 is false, then Op1 is a subset of Op0.
2455 if (*Implied
== false)
2457 // If Op0 is false implies Op1 is true, then at least one is always true.
2458 if (*Implied
== true)
2459 return ConstantInt::getTrue(Op0
->getType());
2461 if (std::optional
<bool> Implied
=
2462 isImpliedCondition(Op1
, Op0
, Q
.DL
, false)) {
2463 // If Op1 is false implies Op0 is false, then Op0 is a subset of Op1.
2464 if (*Implied
== false)
2466 // If Op1 is false implies Op0 is true, then at least one is always true.
2467 if (*Implied
== true)
2468 return ConstantInt::getTrue(Op1
->getType());
2472 if (Value
*V
= simplifyByDomEq(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2478 Value
*llvm::simplifyOrInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
2479 return ::simplifyOrInst(Op0
, Op1
, Q
, RecursionLimit
);
2482 /// Given operands for a Xor, see if we can fold the result.
2483 /// If not, this returns null.
2484 static Value
*simplifyXorInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
2485 unsigned MaxRecurse
) {
2486 if (Constant
*C
= foldOrCommuteConstant(Instruction::Xor
, Op0
, Op1
, Q
))
2489 // X ^ poison -> poison
2490 if (isa
<PoisonValue
>(Op1
))
2493 // A ^ undef -> undef
2494 if (Q
.isUndefValue(Op1
))
2498 if (match(Op1
, m_Zero()))
2503 return Constant::getNullValue(Op0
->getType());
2505 // A ^ ~A = ~A ^ A = -1
2506 if (match(Op0
, m_Not(m_Specific(Op1
))) || match(Op1
, m_Not(m_Specific(Op0
))))
2507 return Constant::getAllOnesValue(Op0
->getType());
2509 auto foldAndOrNot
= [](Value
*X
, Value
*Y
) -> Value
* {
2511 // (~A & B) ^ (A | B) --> A -- There are 8 commuted variants.
2512 if (match(X
, m_c_And(m_Not(m_Value(A
)), m_Value(B
))) &&
2513 match(Y
, m_c_Or(m_Specific(A
), m_Specific(B
))))
2516 // (~A | B) ^ (A & B) --> ~A -- There are 8 commuted variants.
2517 // The 'not' op must contain a complete -1 operand (no undef elements for
2518 // vector) for the transform to be safe.
2520 if (match(X
, m_c_Or(m_CombineAnd(m_Not(m_Value(A
)), m_Value(NotA
)),
2522 match(Y
, m_c_And(m_Specific(A
), m_Specific(B
))))
2527 if (Value
*R
= foldAndOrNot(Op0
, Op1
))
2529 if (Value
*R
= foldAndOrNot(Op1
, Op0
))
2532 if (Value
*V
= simplifyLogicOfAddSub(Op0
, Op1
, Instruction::Xor
))
2535 // Try some generic simplifications for associative operations.
2537 simplifyAssociativeBinOp(Instruction::Xor
, Op0
, Op1
, Q
, MaxRecurse
))
2540 // Threading Xor over selects and phi nodes is pointless, so don't bother.
2541 // Threading over the select in "A ^ select(cond, B, C)" means evaluating
2542 // "A^B" and "A^C" and seeing if they are equal; but they are equal if and
2543 // only if B and C are equal. If B and C are equal then (since we assume
2544 // that operands have already been simplified) "select(cond, B, C)" should
2545 // have been simplified to the common value of B and C already. Analysing
2546 // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
2547 // for threading over phi nodes.
2549 if (Value
*V
= simplifyByDomEq(Instruction::Xor
, Op0
, Op1
, Q
, MaxRecurse
))
2552 // (xor (sub nuw C_Mask, X), C_Mask) -> X
2555 if (match(Op0
, m_NUWSub(m_Specific(Op1
), m_Value(X
))) &&
2556 match(Op1
, m_LowBitMask()))
2563 Value
*llvm::simplifyXorInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
2564 return ::simplifyXorInst(Op0
, Op1
, Q
, RecursionLimit
);
2567 static Type
*getCompareTy(Value
*Op
) {
2568 return CmpInst::makeCmpResultType(Op
->getType());
2571 /// Rummage around inside V looking for something equivalent to the comparison
2572 /// "LHS Pred RHS". Return such a value if found, otherwise return null.
2573 /// Helper function for analyzing max/min idioms.
2574 static Value
*extractEquivalentCondition(Value
*V
, CmpPredicate Pred
,
2575 Value
*LHS
, Value
*RHS
) {
2576 SelectInst
*SI
= dyn_cast
<SelectInst
>(V
);
2579 CmpInst
*Cmp
= dyn_cast
<CmpInst
>(SI
->getCondition());
2582 Value
*CmpLHS
= Cmp
->getOperand(0), *CmpRHS
= Cmp
->getOperand(1);
2583 if (Pred
== Cmp
->getPredicate() && LHS
== CmpLHS
&& RHS
== CmpRHS
)
2585 if (Pred
== CmpInst::getSwappedPredicate(Cmp
->getPredicate()) &&
2586 LHS
== CmpRHS
&& RHS
== CmpLHS
)
2591 /// Return true if the underlying object (storage) must be disjoint from
2592 /// storage returned by any noalias return call.
2593 static bool isAllocDisjoint(const Value
*V
) {
2594 // For allocas, we consider only static ones (dynamic
2595 // allocas might be transformed into calls to malloc not simultaneously
2596 // live with the compared-to allocation). For globals, we exclude symbols
2597 // that might be resolve lazily to symbols in another dynamically-loaded
2598 // library (and, thus, could be malloc'ed by the implementation).
2599 if (const AllocaInst
*AI
= dyn_cast
<AllocaInst
>(V
))
2600 return AI
->isStaticAlloca();
2601 if (const GlobalValue
*GV
= dyn_cast
<GlobalValue
>(V
))
2602 return (GV
->hasLocalLinkage() || GV
->hasHiddenVisibility() ||
2603 GV
->hasProtectedVisibility() || GV
->hasGlobalUnnamedAddr()) &&
2604 !GV
->isThreadLocal();
2605 if (const Argument
*A
= dyn_cast
<Argument
>(V
))
2606 return A
->hasByValAttr();
2610 /// Return true if V1 and V2 are each the base of some distict storage region
2611 /// [V, object_size(V)] which do not overlap. Note that zero sized regions
2612 /// *are* possible, and that zero sized regions do not overlap with any other.
2613 static bool haveNonOverlappingStorage(const Value
*V1
, const Value
*V2
) {
2614 // Global variables always exist, so they always exist during the lifetime
2615 // of each other and all allocas. Global variables themselves usually have
2616 // non-overlapping storage, but since their addresses are constants, the
2617 // case involving two globals does not reach here and is instead handled in
2618 // constant folding.
2620 // Two different allocas usually have different addresses...
2622 // However, if there's an @llvm.stackrestore dynamically in between two
2623 // allocas, they may have the same address. It's tempting to reduce the
2624 // scope of the problem by only looking at *static* allocas here. That would
2625 // cover the majority of allocas while significantly reducing the likelihood
2626 // of having an @llvm.stackrestore pop up in the middle. However, it's not
2627 // actually impossible for an @llvm.stackrestore to pop up in the middle of
2628 // an entry block. Also, if we have a block that's not attached to a
2629 // function, we can't tell if it's "static" under the current definition.
2630 // Theoretically, this problem could be fixed by creating a new kind of
2631 // instruction kind specifically for static allocas. Such a new instruction
2632 // could be required to be at the top of the entry block, thus preventing it
2633 // from being subject to a @llvm.stackrestore. Instcombine could even
2634 // convert regular allocas into these special allocas. It'd be nifty.
2635 // However, until then, this problem remains open.
2637 // So, we'll assume that two non-empty allocas have different addresses
2639 auto isByValArg
= [](const Value
*V
) {
2640 const Argument
*A
= dyn_cast
<Argument
>(V
);
2641 return A
&& A
->hasByValAttr();
2644 // Byval args are backed by store which does not overlap with each other,
2645 // allocas, or globals.
2647 return isa
<AllocaInst
>(V2
) || isa
<GlobalVariable
>(V2
) || isByValArg(V2
);
2649 return isa
<AllocaInst
>(V1
) || isa
<GlobalVariable
>(V1
) || isByValArg(V1
);
2651 return isa
<AllocaInst
>(V1
) &&
2652 (isa
<AllocaInst
>(V2
) || isa
<GlobalVariable
>(V2
));
2655 // A significant optimization not implemented here is assuming that alloca
2656 // addresses are not equal to incoming argument values. They don't *alias*,
2657 // as we say, but that doesn't mean they aren't equal, so we take a
2658 // conservative approach.
2660 // This is inspired in part by C++11 5.10p1:
2661 // "Two pointers of the same type compare equal if and only if they are both
2662 // null, both point to the same function, or both represent the same
2665 // This is pretty permissive.
2667 // It's also partly due to C11 6.5.9p6:
2668 // "Two pointers compare equal if and only if both are null pointers, both are
2669 // pointers to the same object (including a pointer to an object and a
2670 // subobject at its beginning) or function, both are pointers to one past the
2671 // last element of the same array object, or one is a pointer to one past the
2672 // end of one array object and the other is a pointer to the start of a
2673 // different array object that happens to immediately follow the first array
2674 // object in the address space.)
2676 // C11's version is more restrictive, however there's no reason why an argument
2677 // couldn't be a one-past-the-end value for a stack object in the caller and be
2678 // equal to the beginning of a stack object in the callee.
2680 // If the C and C++ standards are ever made sufficiently restrictive in this
2681 // area, it may be possible to update LLVM's semantics accordingly and reinstate
2682 // this optimization.
2683 static Constant
*computePointerICmp(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
2684 const SimplifyQuery
&Q
) {
2685 assert(LHS
->getType() == RHS
->getType() && "Must have same types");
2686 const DataLayout
&DL
= Q
.DL
;
2687 const TargetLibraryInfo
*TLI
= Q
.TLI
;
2689 // We can only fold certain predicates on pointer comparisons.
2694 // Equality comparisons are easy to fold.
2695 case CmpInst::ICMP_EQ
:
2696 case CmpInst::ICMP_NE
:
2699 // We can only handle unsigned relational comparisons because 'inbounds' on
2700 // a GEP only protects against unsigned wrapping.
2701 case CmpInst::ICMP_UGT
:
2702 case CmpInst::ICMP_UGE
:
2703 case CmpInst::ICMP_ULT
:
2704 case CmpInst::ICMP_ULE
:
2705 // However, we have to switch them to their signed variants to handle
2706 // negative indices from the base pointer.
2707 Pred
= ICmpInst::getSignedPredicate(Pred
);
2711 // Strip off any constant offsets so that we can reason about them.
2712 // It's tempting to use getUnderlyingObject or even just stripInBoundsOffsets
2713 // here and compare base addresses like AliasAnalysis does, however there are
2714 // numerous hazards. AliasAnalysis and its utilities rely on special rules
2715 // governing loads and stores which don't apply to icmps. Also, AliasAnalysis
2716 // doesn't need to guarantee pointer inequality when it says NoAlias.
2718 // Even if an non-inbounds GEP occurs along the path we can still optimize
2719 // equality comparisons concerning the result.
2720 bool AllowNonInbounds
= ICmpInst::isEquality(Pred
);
2721 unsigned IndexSize
= DL
.getIndexTypeSizeInBits(LHS
->getType());
2722 APInt
LHSOffset(IndexSize
, 0), RHSOffset(IndexSize
, 0);
2723 LHS
= LHS
->stripAndAccumulateConstantOffsets(DL
, LHSOffset
, AllowNonInbounds
);
2724 RHS
= RHS
->stripAndAccumulateConstantOffsets(DL
, RHSOffset
, AllowNonInbounds
);
2726 // If LHS and RHS are related via constant offsets to the same base
2727 // value, we can replace it with an icmp which just compares the offsets.
2729 return ConstantInt::get(getCompareTy(LHS
),
2730 ICmpInst::compare(LHSOffset
, RHSOffset
, Pred
));
2732 // Various optimizations for (in)equality comparisons.
2733 if (Pred
== CmpInst::ICMP_EQ
|| Pred
== CmpInst::ICMP_NE
) {
2734 // Different non-empty allocations that exist at the same time have
2735 // different addresses (if the program can tell). If the offsets are
2736 // within the bounds of their allocations (and not one-past-the-end!
2737 // so we can't use inbounds!), and their allocations aren't the same,
2738 // the pointers are not equal.
2739 if (haveNonOverlappingStorage(LHS
, RHS
)) {
2740 uint64_t LHSSize
, RHSSize
;
2741 ObjectSizeOpts Opts
;
2742 Opts
.EvalMode
= ObjectSizeOpts::Mode::Min
;
2743 auto *F
= [](Value
*V
) -> Function
* {
2744 if (auto *I
= dyn_cast
<Instruction
>(V
))
2745 return I
->getFunction();
2746 if (auto *A
= dyn_cast
<Argument
>(V
))
2747 return A
->getParent();
2750 Opts
.NullIsUnknownSize
= F
? NullPointerIsDefined(F
) : true;
2751 if (getObjectSize(LHS
, LHSSize
, DL
, TLI
, Opts
) && LHSSize
!= 0 &&
2752 getObjectSize(RHS
, RHSSize
, DL
, TLI
, Opts
) && RHSSize
!= 0) {
2753 APInt Dist
= LHSOffset
- RHSOffset
;
2754 if (Dist
.isNonNegative() ? Dist
.ult(LHSSize
) : (-Dist
).ult(RHSSize
))
2755 return ConstantInt::get(getCompareTy(LHS
),
2756 !CmpInst::isTrueWhenEqual(Pred
));
2760 // If one side of the equality comparison must come from a noalias call
2761 // (meaning a system memory allocation function), and the other side must
2762 // come from a pointer that cannot overlap with dynamically-allocated
2763 // memory within the lifetime of the current function (allocas, byval
2764 // arguments, globals), then determine the comparison result here.
2765 SmallVector
<const Value
*, 8> LHSUObjs
, RHSUObjs
;
2766 getUnderlyingObjects(LHS
, LHSUObjs
);
2767 getUnderlyingObjects(RHS
, RHSUObjs
);
2769 // Is the set of underlying objects all noalias calls?
2770 auto IsNAC
= [](ArrayRef
<const Value
*> Objects
) {
2771 return all_of(Objects
, isNoAliasCall
);
2774 // Is the set of underlying objects all things which must be disjoint from
2775 // noalias calls. We assume that indexing from such disjoint storage
2776 // into the heap is undefined, and thus offsets can be safely ignored.
2777 auto IsAllocDisjoint
= [](ArrayRef
<const Value
*> Objects
) {
2778 return all_of(Objects
, ::isAllocDisjoint
);
2781 if ((IsNAC(LHSUObjs
) && IsAllocDisjoint(RHSUObjs
)) ||
2782 (IsNAC(RHSUObjs
) && IsAllocDisjoint(LHSUObjs
)))
2783 return ConstantInt::get(getCompareTy(LHS
),
2784 !CmpInst::isTrueWhenEqual(Pred
));
2786 // Fold comparisons for non-escaping pointer even if the allocation call
2787 // cannot be elided. We cannot fold malloc comparison to null. Also, the
2788 // dynamic allocation call could be either of the operands. Note that
2789 // the other operand can not be based on the alloc - if it were, then
2790 // the cmp itself would be a capture.
2791 Value
*MI
= nullptr;
2792 if (isAllocLikeFn(LHS
, TLI
) && llvm::isKnownNonZero(RHS
, Q
))
2794 else if (isAllocLikeFn(RHS
, TLI
) && llvm::isKnownNonZero(LHS
, Q
))
2797 // FIXME: This is incorrect, see PR54002. While we can assume that the
2798 // allocation is at an address that makes the comparison false, this
2799 // requires that *all* comparisons to that address be false, which
2800 // InstSimplify cannot guarantee.
2801 struct CustomCaptureTracker
: public CaptureTracker
{
2802 bool Captured
= false;
2803 void tooManyUses() override
{ Captured
= true; }
2804 bool captured(const Use
*U
) override
{
2805 if (auto *ICmp
= dyn_cast
<ICmpInst
>(U
->getUser())) {
2806 // Comparison against value stored in global variable. Given the
2807 // pointer does not escape, its value cannot be guessed and stored
2808 // separately in a global variable.
2809 unsigned OtherIdx
= 1 - U
->getOperandNo();
2810 auto *LI
= dyn_cast
<LoadInst
>(ICmp
->getOperand(OtherIdx
));
2811 if (LI
&& isa
<GlobalVariable
>(LI
->getPointerOperand()))
2819 CustomCaptureTracker Tracker
;
2820 PointerMayBeCaptured(MI
, &Tracker
);
2821 if (!Tracker
.Captured
)
2822 return ConstantInt::get(getCompareTy(LHS
),
2823 CmpInst::isFalseWhenEqual(Pred
));
2831 /// Fold an icmp when its operands have i1 scalar type.
2832 static Value
*simplifyICmpOfBools(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
2833 const SimplifyQuery
&Q
) {
2834 Type
*ITy
= getCompareTy(LHS
); // The return type.
2835 Type
*OpTy
= LHS
->getType(); // The operand type.
2836 if (!OpTy
->isIntOrIntVectorTy(1))
2839 // A boolean compared to true/false can be reduced in 14 out of the 20
2840 // (10 predicates * 2 constants) possible combinations. The other
2841 // 6 cases require a 'not' of the LHS.
2843 auto ExtractNotLHS
= [](Value
*V
) -> Value
* {
2845 if (match(V
, m_Not(m_Value(X
))))
2850 if (match(RHS
, m_Zero())) {
2852 case CmpInst::ICMP_NE
: // X != 0 -> X
2853 case CmpInst::ICMP_UGT
: // X >u 0 -> X
2854 case CmpInst::ICMP_SLT
: // X <s 0 -> X
2857 case CmpInst::ICMP_EQ
: // not(X) == 0 -> X != 0 -> X
2858 case CmpInst::ICMP_ULE
: // not(X) <=u 0 -> X >u 0 -> X
2859 case CmpInst::ICMP_SGE
: // not(X) >=s 0 -> X <s 0 -> X
2860 if (Value
*X
= ExtractNotLHS(LHS
))
2864 case CmpInst::ICMP_ULT
: // X <u 0 -> false
2865 case CmpInst::ICMP_SGT
: // X >s 0 -> false
2866 return getFalse(ITy
);
2868 case CmpInst::ICMP_UGE
: // X >=u 0 -> true
2869 case CmpInst::ICMP_SLE
: // X <=s 0 -> true
2870 return getTrue(ITy
);
2875 } else if (match(RHS
, m_One())) {
2877 case CmpInst::ICMP_EQ
: // X == 1 -> X
2878 case CmpInst::ICMP_UGE
: // X >=u 1 -> X
2879 case CmpInst::ICMP_SLE
: // X <=s -1 -> X
2882 case CmpInst::ICMP_NE
: // not(X) != 1 -> X == 1 -> X
2883 case CmpInst::ICMP_ULT
: // not(X) <=u 1 -> X >=u 1 -> X
2884 case CmpInst::ICMP_SGT
: // not(X) >s 1 -> X <=s -1 -> X
2885 if (Value
*X
= ExtractNotLHS(LHS
))
2889 case CmpInst::ICMP_UGT
: // X >u 1 -> false
2890 case CmpInst::ICMP_SLT
: // X <s -1 -> false
2891 return getFalse(ITy
);
2893 case CmpInst::ICMP_ULE
: // X <=u 1 -> true
2894 case CmpInst::ICMP_SGE
: // X >=s -1 -> true
2895 return getTrue(ITy
);
2905 case ICmpInst::ICMP_UGE
:
2906 if (isImpliedCondition(RHS
, LHS
, Q
.DL
).value_or(false))
2907 return getTrue(ITy
);
2909 case ICmpInst::ICMP_SGE
:
2910 /// For signed comparison, the values for an i1 are 0 and -1
2911 /// respectively. This maps into a truth table of:
2912 /// LHS | RHS | LHS >=s RHS | LHS implies RHS
2913 /// 0 | 0 | 1 (0 >= 0) | 1
2914 /// 0 | 1 | 1 (0 >= -1) | 1
2915 /// 1 | 0 | 0 (-1 >= 0) | 0
2916 /// 1 | 1 | 1 (-1 >= -1) | 1
2917 if (isImpliedCondition(LHS
, RHS
, Q
.DL
).value_or(false))
2918 return getTrue(ITy
);
2920 case ICmpInst::ICMP_ULE
:
2921 if (isImpliedCondition(LHS
, RHS
, Q
.DL
).value_or(false))
2922 return getTrue(ITy
);
2924 case ICmpInst::ICMP_SLE
:
2925 /// SLE follows the same logic as SGE with the LHS and RHS swapped.
2926 if (isImpliedCondition(RHS
, LHS
, Q
.DL
).value_or(false))
2927 return getTrue(ITy
);
2934 /// Try hard to fold icmp with zero RHS because this is a common case.
2935 static Value
*simplifyICmpWithZero(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
2936 const SimplifyQuery
&Q
) {
2937 if (!match(RHS
, m_Zero()))
2940 Type
*ITy
= getCompareTy(LHS
); // The return type.
2943 llvm_unreachable("Unknown ICmp predicate!");
2944 case ICmpInst::ICMP_ULT
:
2945 return getFalse(ITy
);
2946 case ICmpInst::ICMP_UGE
:
2947 return getTrue(ITy
);
2948 case ICmpInst::ICMP_EQ
:
2949 case ICmpInst::ICMP_ULE
:
2950 if (isKnownNonZero(LHS
, Q
))
2951 return getFalse(ITy
);
2953 case ICmpInst::ICMP_NE
:
2954 case ICmpInst::ICMP_UGT
:
2955 if (isKnownNonZero(LHS
, Q
))
2956 return getTrue(ITy
);
2958 case ICmpInst::ICMP_SLT
: {
2959 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
2960 if (LHSKnown
.isNegative())
2961 return getTrue(ITy
);
2962 if (LHSKnown
.isNonNegative())
2963 return getFalse(ITy
);
2966 case ICmpInst::ICMP_SLE
: {
2967 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
2968 if (LHSKnown
.isNegative())
2969 return getTrue(ITy
);
2970 if (LHSKnown
.isNonNegative() && isKnownNonZero(LHS
, Q
))
2971 return getFalse(ITy
);
2974 case ICmpInst::ICMP_SGE
: {
2975 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
2976 if (LHSKnown
.isNegative())
2977 return getFalse(ITy
);
2978 if (LHSKnown
.isNonNegative())
2979 return getTrue(ITy
);
2982 case ICmpInst::ICMP_SGT
: {
2983 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
2984 if (LHSKnown
.isNegative())
2985 return getFalse(ITy
);
2986 if (LHSKnown
.isNonNegative() && isKnownNonZero(LHS
, Q
))
2987 return getTrue(ITy
);
2995 static Value
*simplifyICmpWithConstant(CmpPredicate Pred
, Value
*LHS
,
2996 Value
*RHS
, const InstrInfoQuery
&IIQ
) {
2997 Type
*ITy
= getCompareTy(RHS
); // The return type.
3001 if (!match(RHS
, m_APIntAllowPoison(C
)))
3004 // Sign-bit checks can be optimized to true/false after unsigned
3005 // floating-point casts:
3006 // icmp slt (bitcast (uitofp X)), 0 --> false
3007 // icmp sgt (bitcast (uitofp X)), -1 --> true
3008 if (match(LHS
, m_ElementWiseBitCast(m_UIToFP(m_Value(X
))))) {
3010 if (isSignBitCheck(Pred
, *C
, TrueIfSigned
))
3011 return ConstantInt::getBool(ITy
, !TrueIfSigned
);
3014 // Rule out tautological comparisons (eg., ult 0 or uge 0).
3015 ConstantRange RHS_CR
= ConstantRange::makeExactICmpRegion(Pred
, *C
);
3016 if (RHS_CR
.isEmptySet())
3017 return ConstantInt::getFalse(ITy
);
3018 if (RHS_CR
.isFullSet())
3019 return ConstantInt::getTrue(ITy
);
3021 ConstantRange LHS_CR
=
3022 computeConstantRange(LHS
, CmpInst::isSigned(Pred
), IIQ
.UseInstrInfo
);
3023 if (!LHS_CR
.isFullSet()) {
3024 if (RHS_CR
.contains(LHS_CR
))
3025 return ConstantInt::getTrue(ITy
);
3026 if (RHS_CR
.inverse().contains(LHS_CR
))
3027 return ConstantInt::getFalse(ITy
);
3030 // (mul nuw/nsw X, MulC) != C --> true (if C is not a multiple of MulC)
3031 // (mul nuw/nsw X, MulC) == C --> false (if C is not a multiple of MulC)
3033 if (IIQ
.UseInstrInfo
&& ICmpInst::isEquality(Pred
) &&
3034 ((match(LHS
, m_NUWMul(m_Value(), m_APIntAllowPoison(MulC
))) &&
3035 *MulC
!= 0 && C
->urem(*MulC
) != 0) ||
3036 (match(LHS
, m_NSWMul(m_Value(), m_APIntAllowPoison(MulC
))) &&
3037 *MulC
!= 0 && C
->srem(*MulC
) != 0)))
3038 return ConstantInt::get(ITy
, Pred
== ICmpInst::ICMP_NE
);
3043 enum class MonotonicType
{ GreaterEq
, LowerEq
};
3045 /// Get values V_i such that V uge V_i (GreaterEq) or V ule V_i (LowerEq).
3046 static void getUnsignedMonotonicValues(SmallPtrSetImpl
<Value
*> &Res
, Value
*V
,
3047 MonotonicType Type
, unsigned Depth
= 0) {
3048 if (!Res
.insert(V
).second
)
3051 // Can be increased if useful.
3055 auto *I
= dyn_cast
<Instruction
>(V
);
3060 if (Type
== MonotonicType::GreaterEq
) {
3061 if (match(I
, m_Or(m_Value(X
), m_Value(Y
))) ||
3062 match(I
, m_Intrinsic
<Intrinsic::uadd_sat
>(m_Value(X
), m_Value(Y
)))) {
3063 getUnsignedMonotonicValues(Res
, X
, Type
, Depth
);
3064 getUnsignedMonotonicValues(Res
, Y
, Type
, Depth
);
3067 assert(Type
== MonotonicType::LowerEq
);
3068 switch (I
->getOpcode()) {
3069 case Instruction::And
:
3070 getUnsignedMonotonicValues(Res
, I
->getOperand(0), Type
, Depth
);
3071 getUnsignedMonotonicValues(Res
, I
->getOperand(1), Type
, Depth
);
3073 case Instruction::URem
:
3074 case Instruction::UDiv
:
3075 case Instruction::LShr
:
3076 getUnsignedMonotonicValues(Res
, I
->getOperand(0), Type
, Depth
);
3078 case Instruction::Call
:
3079 if (match(I
, m_Intrinsic
<Intrinsic::usub_sat
>(m_Value(X
))))
3080 getUnsignedMonotonicValues(Res
, X
, Type
, Depth
);
3088 static Value
*simplifyICmpUsingMonotonicValues(CmpPredicate Pred
, Value
*LHS
,
3090 if (Pred
!= ICmpInst::ICMP_UGE
&& Pred
!= ICmpInst::ICMP_ULT
)
3093 // We have LHS uge GreaterValues and LowerValues uge RHS. If any of the
3094 // GreaterValues and LowerValues are the same, it follows that LHS uge RHS.
3095 SmallPtrSet
<Value
*, 4> GreaterValues
;
3096 SmallPtrSet
<Value
*, 4> LowerValues
;
3097 getUnsignedMonotonicValues(GreaterValues
, LHS
, MonotonicType::GreaterEq
);
3098 getUnsignedMonotonicValues(LowerValues
, RHS
, MonotonicType::LowerEq
);
3099 for (Value
*GV
: GreaterValues
)
3100 if (LowerValues
.contains(GV
))
3101 return ConstantInt::getBool(getCompareTy(LHS
),
3102 Pred
== ICmpInst::ICMP_UGE
);
3106 static Value
*simplifyICmpWithBinOpOnLHS(CmpPredicate Pred
, BinaryOperator
*LBO
,
3107 Value
*RHS
, const SimplifyQuery
&Q
,
3108 unsigned MaxRecurse
) {
3109 Type
*ITy
= getCompareTy(RHS
); // The return type.
3112 // icmp pred (or X, Y), X
3113 if (match(LBO
, m_c_Or(m_Value(Y
), m_Specific(RHS
)))) {
3114 if (Pred
== ICmpInst::ICMP_SLT
|| Pred
== ICmpInst::ICMP_SGE
) {
3115 KnownBits RHSKnown
= computeKnownBits(RHS
, /* Depth */ 0, Q
);
3116 KnownBits YKnown
= computeKnownBits(Y
, /* Depth */ 0, Q
);
3117 if (RHSKnown
.isNonNegative() && YKnown
.isNegative())
3118 return Pred
== ICmpInst::ICMP_SLT
? getTrue(ITy
) : getFalse(ITy
);
3119 if (RHSKnown
.isNegative() || YKnown
.isNonNegative())
3120 return Pred
== ICmpInst::ICMP_SLT
? getFalse(ITy
) : getTrue(ITy
);
3124 // icmp pred (urem X, Y), Y
3125 if (match(LBO
, m_URem(m_Value(), m_Specific(RHS
)))) {
3129 case ICmpInst::ICMP_SGT
:
3130 case ICmpInst::ICMP_SGE
: {
3131 KnownBits Known
= computeKnownBits(RHS
, /* Depth */ 0, Q
);
3132 if (!Known
.isNonNegative())
3136 case ICmpInst::ICMP_EQ
:
3137 case ICmpInst::ICMP_UGT
:
3138 case ICmpInst::ICMP_UGE
:
3139 return getFalse(ITy
);
3140 case ICmpInst::ICMP_SLT
:
3141 case ICmpInst::ICMP_SLE
: {
3142 KnownBits Known
= computeKnownBits(RHS
, /* Depth */ 0, Q
);
3143 if (!Known
.isNonNegative())
3147 case ICmpInst::ICMP_NE
:
3148 case ICmpInst::ICMP_ULT
:
3149 case ICmpInst::ICMP_ULE
:
3150 return getTrue(ITy
);
3155 // x >>u C <u x --> true for C != 0.
3156 // x >>u C != x --> true for C != 0.
3157 // x >>u C >=u x --> false for C != 0.
3158 // x >>u C == x --> false for C != 0.
3159 // x udiv C <u x --> true for C != 1.
3160 // x udiv C != x --> true for C != 1.
3161 // x udiv C >=u x --> false for C != 1.
3162 // x udiv C == x --> false for C != 1.
3163 // TODO: allow non-constant shift amount/divisor
3165 if ((match(LBO
, m_LShr(m_Specific(RHS
), m_APInt(C
))) && *C
!= 0) ||
3166 (match(LBO
, m_UDiv(m_Specific(RHS
), m_APInt(C
))) && *C
!= 1)) {
3167 if (isKnownNonZero(RHS
, Q
)) {
3171 case ICmpInst::ICMP_EQ
:
3172 case ICmpInst::ICMP_UGE
:
3173 case ICmpInst::ICMP_UGT
:
3174 return getFalse(ITy
);
3175 case ICmpInst::ICMP_NE
:
3176 case ICmpInst::ICMP_ULT
:
3177 case ICmpInst::ICMP_ULE
:
3178 return getTrue(ITy
);
3183 // (x*C1)/C2 <= x for C1 <= C2.
3184 // This holds even if the multiplication overflows: Assume that x != 0 and
3185 // arithmetic is modulo M. For overflow to occur we must have C1 >= M/x and
3186 // thus C2 >= M/x. It follows that (x*C1)/C2 <= (M-1)/C2 <= ((M-1)*x)/M < x.
3188 // Additionally, either the multiplication and division might be represented
3190 // (x*C1)>>C2 <= x for C1 < 2**C2.
3191 // (x<<C1)/C2 <= x for 2**C1 < C2.
3192 const APInt
*C1
, *C2
;
3193 if ((match(LBO
, m_UDiv(m_Mul(m_Specific(RHS
), m_APInt(C1
)), m_APInt(C2
))) &&
3195 (match(LBO
, m_LShr(m_Mul(m_Specific(RHS
), m_APInt(C1
)), m_APInt(C2
))) &&
3196 C1
->ule(APInt(C2
->getBitWidth(), 1) << *C2
)) ||
3197 (match(LBO
, m_UDiv(m_Shl(m_Specific(RHS
), m_APInt(C1
)), m_APInt(C2
))) &&
3198 (APInt(C1
->getBitWidth(), 1) << *C1
).ule(*C2
))) {
3199 if (Pred
== ICmpInst::ICMP_UGT
)
3200 return getFalse(ITy
);
3201 if (Pred
== ICmpInst::ICMP_ULE
)
3202 return getTrue(ITy
);
3205 // (sub C, X) == X, C is odd --> false
3206 // (sub C, X) != X, C is odd --> true
3207 if (match(LBO
, m_Sub(m_APIntAllowPoison(C
), m_Specific(RHS
))) &&
3208 (*C
& 1) == 1 && ICmpInst::isEquality(Pred
))
3209 return (Pred
== ICmpInst::ICMP_EQ
) ? getFalse(ITy
) : getTrue(ITy
);
3214 // If only one of the icmp's operands has NSW flags, try to prove that:
3216 // icmp slt (x + C1), (x +nsw C2)
3218 // is equivalent to:
3222 // which is true if x + C2 has the NSW flags set and:
3223 // *) C1 < C2 && C1 >= 0, or
3224 // *) C2 < C1 && C1 <= 0.
3226 static bool trySimplifyICmpWithAdds(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
3227 const InstrInfoQuery
&IIQ
) {
3228 // TODO: only support icmp slt for now.
3229 if (Pred
!= CmpInst::ICMP_SLT
|| !IIQ
.UseInstrInfo
)
3232 // Canonicalize nsw add as RHS.
3233 if (!match(RHS
, m_NSWAdd(m_Value(), m_Value())))
3234 std::swap(LHS
, RHS
);
3235 if (!match(RHS
, m_NSWAdd(m_Value(), m_Value())))
3239 const APInt
*C1
, *C2
;
3240 if (!match(LHS
, m_Add(m_Value(X
), m_APInt(C1
))) ||
3241 !match(RHS
, m_Add(m_Specific(X
), m_APInt(C2
))))
3244 return (C1
->slt(*C2
) && C1
->isNonNegative()) ||
3245 (C2
->slt(*C1
) && C1
->isNonPositive());
3248 /// TODO: A large part of this logic is duplicated in InstCombine's
3249 /// foldICmpBinOp(). We should be able to share that and avoid the code
3251 static Value
*simplifyICmpWithBinOp(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
3252 const SimplifyQuery
&Q
,
3253 unsigned MaxRecurse
) {
3254 BinaryOperator
*LBO
= dyn_cast
<BinaryOperator
>(LHS
);
3255 BinaryOperator
*RBO
= dyn_cast
<BinaryOperator
>(RHS
);
3256 if (MaxRecurse
&& (LBO
|| RBO
)) {
3257 // Analyze the case when either LHS or RHS is an add instruction.
3258 Value
*A
= nullptr, *B
= nullptr, *C
= nullptr, *D
= nullptr;
3259 // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
3260 bool NoLHSWrapProblem
= false, NoRHSWrapProblem
= false;
3261 if (LBO
&& LBO
->getOpcode() == Instruction::Add
) {
3262 A
= LBO
->getOperand(0);
3263 B
= LBO
->getOperand(1);
3265 ICmpInst::isEquality(Pred
) ||
3266 (CmpInst::isUnsigned(Pred
) &&
3267 Q
.IIQ
.hasNoUnsignedWrap(cast
<OverflowingBinaryOperator
>(LBO
))) ||
3268 (CmpInst::isSigned(Pred
) &&
3269 Q
.IIQ
.hasNoSignedWrap(cast
<OverflowingBinaryOperator
>(LBO
)));
3271 if (RBO
&& RBO
->getOpcode() == Instruction::Add
) {
3272 C
= RBO
->getOperand(0);
3273 D
= RBO
->getOperand(1);
3275 ICmpInst::isEquality(Pred
) ||
3276 (CmpInst::isUnsigned(Pred
) &&
3277 Q
.IIQ
.hasNoUnsignedWrap(cast
<OverflowingBinaryOperator
>(RBO
))) ||
3278 (CmpInst::isSigned(Pred
) &&
3279 Q
.IIQ
.hasNoSignedWrap(cast
<OverflowingBinaryOperator
>(RBO
)));
3282 // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
3283 if ((A
== RHS
|| B
== RHS
) && NoLHSWrapProblem
)
3284 if (Value
*V
= simplifyICmpInst(Pred
, A
== RHS
? B
: A
,
3285 Constant::getNullValue(RHS
->getType()), Q
,
3289 // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
3290 if ((C
== LHS
|| D
== LHS
) && NoRHSWrapProblem
)
3292 simplifyICmpInst(Pred
, Constant::getNullValue(LHS
->getType()),
3293 C
== LHS
? D
: C
, Q
, MaxRecurse
- 1))
3296 // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
3297 bool CanSimplify
= (NoLHSWrapProblem
&& NoRHSWrapProblem
) ||
3298 trySimplifyICmpWithAdds(Pred
, LHS
, RHS
, Q
.IIQ
);
3299 if (A
&& C
&& (A
== C
|| A
== D
|| B
== C
|| B
== D
) && CanSimplify
) {
3300 // Determine Y and Z in the form icmp (X+Y), (X+Z).
3303 // C + B == C + D -> B == D
3306 } else if (A
== D
) {
3307 // D + B == C + D -> B == C
3310 } else if (B
== C
) {
3311 // A + C == C + D -> A == D
3316 // A + D == C + D -> A == C
3320 if (Value
*V
= simplifyICmpInst(Pred
, Y
, Z
, Q
, MaxRecurse
- 1))
3326 if (Value
*V
= simplifyICmpWithBinOpOnLHS(Pred
, LBO
, RHS
, Q
, MaxRecurse
))
3330 if (Value
*V
= simplifyICmpWithBinOpOnLHS(
3331 ICmpInst::getSwappedPredicate(Pred
), RBO
, LHS
, Q
, MaxRecurse
))
3334 // 0 - (zext X) pred C
3335 if (!CmpInst::isUnsigned(Pred
) && match(LHS
, m_Neg(m_ZExt(m_Value())))) {
3337 if (match(RHS
, m_APInt(C
))) {
3338 if (C
->isStrictlyPositive()) {
3339 if (Pred
== ICmpInst::ICMP_SLT
|| Pred
== ICmpInst::ICMP_NE
)
3340 return ConstantInt::getTrue(getCompareTy(RHS
));
3341 if (Pred
== ICmpInst::ICMP_SGE
|| Pred
== ICmpInst::ICMP_EQ
)
3342 return ConstantInt::getFalse(getCompareTy(RHS
));
3344 if (C
->isNonNegative()) {
3345 if (Pred
== ICmpInst::ICMP_SLE
)
3346 return ConstantInt::getTrue(getCompareTy(RHS
));
3347 if (Pred
== ICmpInst::ICMP_SGT
)
3348 return ConstantInt::getFalse(getCompareTy(RHS
));
3353 // If C2 is a power-of-2 and C is not:
3354 // (C2 << X) == C --> false
3355 // (C2 << X) != C --> true
3357 if (match(LHS
, m_Shl(m_Power2(), m_Value())) &&
3358 match(RHS
, m_APIntAllowPoison(C
)) && !C
->isPowerOf2()) {
3359 // C2 << X can equal zero in some circumstances.
3360 // This simplification might be unsafe if C is zero.
3362 // We know it is safe if:
3363 // - The shift is nsw. We can't shift out the one bit.
3364 // - The shift is nuw. We can't shift out the one bit.
3367 if (Q
.IIQ
.hasNoSignedWrap(cast
<OverflowingBinaryOperator
>(LBO
)) ||
3368 Q
.IIQ
.hasNoUnsignedWrap(cast
<OverflowingBinaryOperator
>(LBO
)) ||
3369 match(LHS
, m_Shl(m_One(), m_Value())) || !C
->isZero()) {
3370 if (Pred
== ICmpInst::ICMP_EQ
)
3371 return ConstantInt::getFalse(getCompareTy(RHS
));
3372 if (Pred
== ICmpInst::ICMP_NE
)
3373 return ConstantInt::getTrue(getCompareTy(RHS
));
3377 // If C is a power-of-2:
3378 // (C << X) >u 0x8000 --> false
3379 // (C << X) <=u 0x8000 --> true
3380 if (match(LHS
, m_Shl(m_Power2(), m_Value())) && match(RHS
, m_SignMask())) {
3381 if (Pred
== ICmpInst::ICMP_UGT
)
3382 return ConstantInt::getFalse(getCompareTy(RHS
));
3383 if (Pred
== ICmpInst::ICMP_ULE
)
3384 return ConstantInt::getTrue(getCompareTy(RHS
));
3387 if (!MaxRecurse
|| !LBO
|| !RBO
|| LBO
->getOpcode() != RBO
->getOpcode())
3390 if (LBO
->getOperand(0) == RBO
->getOperand(0)) {
3391 switch (LBO
->getOpcode()) {
3394 case Instruction::Shl
: {
3395 bool NUW
= Q
.IIQ
.hasNoUnsignedWrap(LBO
) && Q
.IIQ
.hasNoUnsignedWrap(RBO
);
3396 bool NSW
= Q
.IIQ
.hasNoSignedWrap(LBO
) && Q
.IIQ
.hasNoSignedWrap(RBO
);
3397 if (!NUW
|| (ICmpInst::isSigned(Pred
) && !NSW
) ||
3398 !isKnownNonZero(LBO
->getOperand(0), Q
))
3400 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(1),
3401 RBO
->getOperand(1), Q
, MaxRecurse
- 1))
3405 // If C1 & C2 == C1, A = X and/or C1, B = X and/or C2:
3406 // icmp ule A, B -> true
3407 // icmp ugt A, B -> false
3408 // icmp sle A, B -> true (C1 and C2 are the same sign)
3409 // icmp sgt A, B -> false (C1 and C2 are the same sign)
3410 case Instruction::And
:
3411 case Instruction::Or
: {
3412 const APInt
*C1
, *C2
;
3413 if (ICmpInst::isRelational(Pred
) &&
3414 match(LBO
->getOperand(1), m_APInt(C1
)) &&
3415 match(RBO
->getOperand(1), m_APInt(C2
))) {
3416 if (!C1
->isSubsetOf(*C2
)) {
3418 Pred
= ICmpInst::getSwappedPredicate(Pred
);
3420 if (C1
->isSubsetOf(*C2
)) {
3421 if (Pred
== ICmpInst::ICMP_ULE
)
3422 return ConstantInt::getTrue(getCompareTy(LHS
));
3423 if (Pred
== ICmpInst::ICMP_UGT
)
3424 return ConstantInt::getFalse(getCompareTy(LHS
));
3425 if (C1
->isNonNegative() == C2
->isNonNegative()) {
3426 if (Pred
== ICmpInst::ICMP_SLE
)
3427 return ConstantInt::getTrue(getCompareTy(LHS
));
3428 if (Pred
== ICmpInst::ICMP_SGT
)
3429 return ConstantInt::getFalse(getCompareTy(LHS
));
3438 if (LBO
->getOperand(1) == RBO
->getOperand(1)) {
3439 switch (LBO
->getOpcode()) {
3442 case Instruction::UDiv
:
3443 case Instruction::LShr
:
3444 if (ICmpInst::isSigned(Pred
) || !Q
.IIQ
.isExact(LBO
) ||
3445 !Q
.IIQ
.isExact(RBO
))
3447 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3448 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3451 case Instruction::SDiv
:
3452 if (!ICmpInst::isEquality(Pred
) || !Q
.IIQ
.isExact(LBO
) ||
3453 !Q
.IIQ
.isExact(RBO
))
3455 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3456 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3459 case Instruction::AShr
:
3460 if (!Q
.IIQ
.isExact(LBO
) || !Q
.IIQ
.isExact(RBO
))
3462 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3463 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3466 case Instruction::Shl
: {
3467 bool NUW
= Q
.IIQ
.hasNoUnsignedWrap(LBO
) && Q
.IIQ
.hasNoUnsignedWrap(RBO
);
3468 bool NSW
= Q
.IIQ
.hasNoSignedWrap(LBO
) && Q
.IIQ
.hasNoSignedWrap(RBO
);
3471 if (!NSW
&& ICmpInst::isSigned(Pred
))
3473 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3474 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3483 /// simplify integer comparisons where at least one operand of the compare
3484 /// matches an integer min/max idiom.
3485 static Value
*simplifyICmpWithMinMax(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
3486 const SimplifyQuery
&Q
,
3487 unsigned MaxRecurse
) {
3488 Type
*ITy
= getCompareTy(LHS
); // The return type.
3490 CmpInst::Predicate P
= CmpInst::BAD_ICMP_PREDICATE
;
3491 CmpInst::Predicate EqP
; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
3493 // Signed variants on "max(a,b)>=a -> true".
3494 if (match(LHS
, m_SMax(m_Value(A
), m_Value(B
))) && (A
== RHS
|| B
== RHS
)) {
3496 std::swap(A
, B
); // smax(A, B) pred A.
3497 EqP
= CmpInst::ICMP_SGE
; // "A == smax(A, B)" iff "A sge B".
3498 // We analyze this as smax(A, B) pred A.
3500 } else if (match(RHS
, m_SMax(m_Value(A
), m_Value(B
))) &&
3501 (A
== LHS
|| B
== LHS
)) {
3503 std::swap(A
, B
); // A pred smax(A, B).
3504 EqP
= CmpInst::ICMP_SGE
; // "A == smax(A, B)" iff "A sge B".
3505 // We analyze this as smax(A, B) swapped-pred A.
3506 P
= CmpInst::getSwappedPredicate(Pred
);
3507 } else if (match(LHS
, m_SMin(m_Value(A
), m_Value(B
))) &&
3508 (A
== RHS
|| B
== RHS
)) {
3510 std::swap(A
, B
); // smin(A, B) pred A.
3511 EqP
= CmpInst::ICMP_SLE
; // "A == smin(A, B)" iff "A sle B".
3512 // We analyze this as smax(-A, -B) swapped-pred -A.
3513 // Note that we do not need to actually form -A or -B thanks to EqP.
3514 P
= CmpInst::getSwappedPredicate(Pred
);
3515 } else if (match(RHS
, m_SMin(m_Value(A
), m_Value(B
))) &&
3516 (A
== LHS
|| B
== LHS
)) {
3518 std::swap(A
, B
); // A pred smin(A, B).
3519 EqP
= CmpInst::ICMP_SLE
; // "A == smin(A, B)" iff "A sle B".
3520 // We analyze this as smax(-A, -B) pred -A.
3521 // Note that we do not need to actually form -A or -B thanks to EqP.
3524 if (P
!= CmpInst::BAD_ICMP_PREDICATE
) {
3525 // Cases correspond to "max(A, B) p A".
3529 case CmpInst::ICMP_EQ
:
3530 case CmpInst::ICMP_SLE
:
3531 // Equivalent to "A EqP B". This may be the same as the condition tested
3532 // in the max/min; if so, we can just return that.
3533 if (Value
*V
= extractEquivalentCondition(LHS
, EqP
, A
, B
))
3535 if (Value
*V
= extractEquivalentCondition(RHS
, EqP
, A
, B
))
3537 // Otherwise, see if "A EqP B" simplifies.
3539 if (Value
*V
= simplifyICmpInst(EqP
, A
, B
, Q
, MaxRecurse
- 1))
3542 case CmpInst::ICMP_NE
:
3543 case CmpInst::ICMP_SGT
: {
3544 CmpInst::Predicate InvEqP
= CmpInst::getInversePredicate(EqP
);
3545 // Equivalent to "A InvEqP B". This may be the same as the condition
3546 // tested in the max/min; if so, we can just return that.
3547 if (Value
*V
= extractEquivalentCondition(LHS
, InvEqP
, A
, B
))
3549 if (Value
*V
= extractEquivalentCondition(RHS
, InvEqP
, A
, B
))
3551 // Otherwise, see if "A InvEqP B" simplifies.
3553 if (Value
*V
= simplifyICmpInst(InvEqP
, A
, B
, Q
, MaxRecurse
- 1))
3557 case CmpInst::ICMP_SGE
:
3559 return getTrue(ITy
);
3560 case CmpInst::ICMP_SLT
:
3562 return getFalse(ITy
);
3566 // Unsigned variants on "max(a,b)>=a -> true".
3567 P
= CmpInst::BAD_ICMP_PREDICATE
;
3568 if (match(LHS
, m_UMax(m_Value(A
), m_Value(B
))) && (A
== RHS
|| B
== RHS
)) {
3570 std::swap(A
, B
); // umax(A, B) pred A.
3571 EqP
= CmpInst::ICMP_UGE
; // "A == umax(A, B)" iff "A uge B".
3572 // We analyze this as umax(A, B) pred A.
3574 } else if (match(RHS
, m_UMax(m_Value(A
), m_Value(B
))) &&
3575 (A
== LHS
|| B
== LHS
)) {
3577 std::swap(A
, B
); // A pred umax(A, B).
3578 EqP
= CmpInst::ICMP_UGE
; // "A == umax(A, B)" iff "A uge B".
3579 // We analyze this as umax(A, B) swapped-pred A.
3580 P
= CmpInst::getSwappedPredicate(Pred
);
3581 } else if (match(LHS
, m_UMin(m_Value(A
), m_Value(B
))) &&
3582 (A
== RHS
|| B
== RHS
)) {
3584 std::swap(A
, B
); // umin(A, B) pred A.
3585 EqP
= CmpInst::ICMP_ULE
; // "A == umin(A, B)" iff "A ule B".
3586 // We analyze this as umax(-A, -B) swapped-pred -A.
3587 // Note that we do not need to actually form -A or -B thanks to EqP.
3588 P
= CmpInst::getSwappedPredicate(Pred
);
3589 } else if (match(RHS
, m_UMin(m_Value(A
), m_Value(B
))) &&
3590 (A
== LHS
|| B
== LHS
)) {
3592 std::swap(A
, B
); // A pred umin(A, B).
3593 EqP
= CmpInst::ICMP_ULE
; // "A == umin(A, B)" iff "A ule B".
3594 // We analyze this as umax(-A, -B) pred -A.
3595 // Note that we do not need to actually form -A or -B thanks to EqP.
3598 if (P
!= CmpInst::BAD_ICMP_PREDICATE
) {
3599 // Cases correspond to "max(A, B) p A".
3603 case CmpInst::ICMP_EQ
:
3604 case CmpInst::ICMP_ULE
:
3605 // Equivalent to "A EqP B". This may be the same as the condition tested
3606 // in the max/min; if so, we can just return that.
3607 if (Value
*V
= extractEquivalentCondition(LHS
, EqP
, A
, B
))
3609 if (Value
*V
= extractEquivalentCondition(RHS
, EqP
, A
, B
))
3611 // Otherwise, see if "A EqP B" simplifies.
3613 if (Value
*V
= simplifyICmpInst(EqP
, A
, B
, Q
, MaxRecurse
- 1))
3616 case CmpInst::ICMP_NE
:
3617 case CmpInst::ICMP_UGT
: {
3618 CmpInst::Predicate InvEqP
= CmpInst::getInversePredicate(EqP
);
3619 // Equivalent to "A InvEqP B". This may be the same as the condition
3620 // tested in the max/min; if so, we can just return that.
3621 if (Value
*V
= extractEquivalentCondition(LHS
, InvEqP
, A
, B
))
3623 if (Value
*V
= extractEquivalentCondition(RHS
, InvEqP
, A
, B
))
3625 // Otherwise, see if "A InvEqP B" simplifies.
3627 if (Value
*V
= simplifyICmpInst(InvEqP
, A
, B
, Q
, MaxRecurse
- 1))
3631 case CmpInst::ICMP_UGE
:
3632 return getTrue(ITy
);
3633 case CmpInst::ICMP_ULT
:
3634 return getFalse(ITy
);
3638 // Comparing 1 each of min/max with a common operand?
3639 // Canonicalize min operand to RHS.
3640 if (match(LHS
, m_UMin(m_Value(), m_Value())) ||
3641 match(LHS
, m_SMin(m_Value(), m_Value()))) {
3642 std::swap(LHS
, RHS
);
3643 Pred
= ICmpInst::getSwappedPredicate(Pred
);
3647 if (match(LHS
, m_SMax(m_Value(A
), m_Value(B
))) &&
3648 match(RHS
, m_SMin(m_Value(C
), m_Value(D
))) &&
3649 (A
== C
|| A
== D
|| B
== C
|| B
== D
)) {
3650 // smax(A, B) >=s smin(A, D) --> true
3651 if (Pred
== CmpInst::ICMP_SGE
)
3652 return getTrue(ITy
);
3653 // smax(A, B) <s smin(A, D) --> false
3654 if (Pred
== CmpInst::ICMP_SLT
)
3655 return getFalse(ITy
);
3656 } else if (match(LHS
, m_UMax(m_Value(A
), m_Value(B
))) &&
3657 match(RHS
, m_UMin(m_Value(C
), m_Value(D
))) &&
3658 (A
== C
|| A
== D
|| B
== C
|| B
== D
)) {
3659 // umax(A, B) >=u umin(A, D) --> true
3660 if (Pred
== CmpInst::ICMP_UGE
)
3661 return getTrue(ITy
);
3662 // umax(A, B) <u umin(A, D) --> false
3663 if (Pred
== CmpInst::ICMP_ULT
)
3664 return getFalse(ITy
);
3670 static Value
*simplifyICmpWithDominatingAssume(CmpPredicate Predicate
,
3671 Value
*LHS
, Value
*RHS
,
3672 const SimplifyQuery
&Q
) {
3673 // Gracefully handle instructions that have not been inserted yet.
3674 if (!Q
.AC
|| !Q
.CxtI
)
3677 for (Value
*AssumeBaseOp
: {LHS
, RHS
}) {
3678 for (auto &AssumeVH
: Q
.AC
->assumptionsFor(AssumeBaseOp
)) {
3682 CallInst
*Assume
= cast
<CallInst
>(AssumeVH
);
3683 if (std::optional
<bool> Imp
= isImpliedCondition(
3684 Assume
->getArgOperand(0), Predicate
, LHS
, RHS
, Q
.DL
))
3685 if (isValidAssumeForContext(Assume
, Q
.CxtI
, Q
.DT
))
3686 return ConstantInt::get(getCompareTy(LHS
), *Imp
);
3693 static Value
*simplifyICmpWithIntrinsicOnLHS(CmpPredicate Pred
, Value
*LHS
,
3695 auto *II
= dyn_cast
<IntrinsicInst
>(LHS
);
3699 switch (II
->getIntrinsicID()) {
3700 case Intrinsic::uadd_sat
:
3701 // uadd.sat(X, Y) uge X + Y
3702 if (match(RHS
, m_c_Add(m_Specific(II
->getArgOperand(0)),
3703 m_Specific(II
->getArgOperand(1))))) {
3704 if (Pred
== ICmpInst::ICMP_UGE
)
3705 return ConstantInt::getTrue(getCompareTy(II
));
3706 if (Pred
== ICmpInst::ICMP_ULT
)
3707 return ConstantInt::getFalse(getCompareTy(II
));
3710 case Intrinsic::usub_sat
:
3711 // usub.sat(X, Y) ule X - Y
3712 if (match(RHS
, m_Sub(m_Specific(II
->getArgOperand(0)),
3713 m_Specific(II
->getArgOperand(1))))) {
3714 if (Pred
== ICmpInst::ICMP_ULE
)
3715 return ConstantInt::getTrue(getCompareTy(II
));
3716 if (Pred
== ICmpInst::ICMP_UGT
)
3717 return ConstantInt::getFalse(getCompareTy(II
));
3725 /// Helper method to get range from metadata or attribute.
3726 static std::optional
<ConstantRange
> getRange(Value
*V
,
3727 const InstrInfoQuery
&IIQ
) {
3728 if (Instruction
*I
= dyn_cast
<Instruction
>(V
))
3729 if (MDNode
*MD
= IIQ
.getMetadata(I
, LLVMContext::MD_range
))
3730 return getConstantRangeFromMetadata(*MD
);
3732 if (const Argument
*A
= dyn_cast
<Argument
>(V
))
3733 return A
->getRange();
3734 else if (const CallBase
*CB
= dyn_cast
<CallBase
>(V
))
3735 return CB
->getRange();
3737 return std::nullopt
;
3740 /// Given operands for an ICmpInst, see if we can fold the result.
3741 /// If not, this returns null.
3742 static Value
*simplifyICmpInst(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
3743 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
3744 assert(CmpInst::isIntPredicate(Pred
) && "Not an integer compare!");
3746 if (Constant
*CLHS
= dyn_cast
<Constant
>(LHS
)) {
3747 if (Constant
*CRHS
= dyn_cast
<Constant
>(RHS
))
3748 return ConstantFoldCompareInstOperands(Pred
, CLHS
, CRHS
, Q
.DL
, Q
.TLI
);
3750 // If we have a constant, make sure it is on the RHS.
3751 std::swap(LHS
, RHS
);
3752 Pred
= CmpInst::getSwappedPredicate(Pred
);
3754 assert(!isa
<UndefValue
>(LHS
) && "Unexpected icmp undef,%X");
3756 Type
*ITy
= getCompareTy(LHS
); // The return type.
3758 // icmp poison, X -> poison
3759 if (isa
<PoisonValue
>(RHS
))
3760 return PoisonValue::get(ITy
);
3762 // For EQ and NE, we can always pick a value for the undef to make the
3763 // predicate pass or fail, so we can return undef.
3764 // Matches behavior in llvm::ConstantFoldCompareInstruction.
3765 if (Q
.isUndefValue(RHS
) && ICmpInst::isEquality(Pred
))
3766 return UndefValue::get(ITy
);
3768 // icmp X, X -> true/false
3769 // icmp X, undef -> true/false because undef could be X.
3770 if (LHS
== RHS
|| Q
.isUndefValue(RHS
))
3771 return ConstantInt::get(ITy
, CmpInst::isTrueWhenEqual(Pred
));
3773 if (Value
*V
= simplifyICmpOfBools(Pred
, LHS
, RHS
, Q
))
3776 // TODO: Sink/common this with other potentially expensive calls that use
3777 // ValueTracking? See comment below for isKnownNonEqual().
3778 if (Value
*V
= simplifyICmpWithZero(Pred
, LHS
, RHS
, Q
))
3781 if (Value
*V
= simplifyICmpWithConstant(Pred
, LHS
, RHS
, Q
.IIQ
))
3784 // If both operands have range metadata, use the metadata
3785 // to simplify the comparison.
3786 if (std::optional
<ConstantRange
> RhsCr
= getRange(RHS
, Q
.IIQ
))
3787 if (std::optional
<ConstantRange
> LhsCr
= getRange(LHS
, Q
.IIQ
)) {
3788 if (LhsCr
->icmp(Pred
, *RhsCr
))
3789 return ConstantInt::getTrue(ITy
);
3791 if (LhsCr
->icmp(CmpInst::getInversePredicate(Pred
), *RhsCr
))
3792 return ConstantInt::getFalse(ITy
);
3795 // Compare of cast, for example (zext X) != 0 -> X != 0
3796 if (isa
<CastInst
>(LHS
) && (isa
<Constant
>(RHS
) || isa
<CastInst
>(RHS
))) {
3797 Instruction
*LI
= cast
<CastInst
>(LHS
);
3798 Value
*SrcOp
= LI
->getOperand(0);
3799 Type
*SrcTy
= SrcOp
->getType();
3800 Type
*DstTy
= LI
->getType();
3802 // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
3803 // if the integer type is the same size as the pointer type.
3804 if (MaxRecurse
&& isa
<PtrToIntInst
>(LI
) &&
3805 Q
.DL
.getTypeSizeInBits(SrcTy
) == DstTy
->getPrimitiveSizeInBits()) {
3806 if (Constant
*RHSC
= dyn_cast
<Constant
>(RHS
)) {
3807 // Transfer the cast to the constant.
3808 if (Value
*V
= simplifyICmpInst(Pred
, SrcOp
,
3809 ConstantExpr::getIntToPtr(RHSC
, SrcTy
),
3812 } else if (PtrToIntInst
*RI
= dyn_cast
<PtrToIntInst
>(RHS
)) {
3813 if (RI
->getOperand(0)->getType() == SrcTy
)
3814 // Compare without the cast.
3815 if (Value
*V
= simplifyICmpInst(Pred
, SrcOp
, RI
->getOperand(0), Q
,
3821 if (isa
<ZExtInst
>(LHS
)) {
3822 // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
3824 if (ZExtInst
*RI
= dyn_cast
<ZExtInst
>(RHS
)) {
3825 if (MaxRecurse
&& SrcTy
== RI
->getOperand(0)->getType())
3826 // Compare X and Y. Note that signed predicates become unsigned.
3828 simplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred
), SrcOp
,
3829 RI
->getOperand(0), Q
, MaxRecurse
- 1))
3832 // Fold (zext X) ule (sext X), (zext X) sge (sext X) to true.
3833 else if (SExtInst
*RI
= dyn_cast
<SExtInst
>(RHS
)) {
3834 if (SrcOp
== RI
->getOperand(0)) {
3835 if (Pred
== ICmpInst::ICMP_ULE
|| Pred
== ICmpInst::ICMP_SGE
)
3836 return ConstantInt::getTrue(ITy
);
3837 if (Pred
== ICmpInst::ICMP_UGT
|| Pred
== ICmpInst::ICMP_SLT
)
3838 return ConstantInt::getFalse(ITy
);
3841 // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
3842 // too. If not, then try to deduce the result of the comparison.
3843 else if (match(RHS
, m_ImmConstant())) {
3844 Constant
*C
= dyn_cast
<Constant
>(RHS
);
3845 assert(C
!= nullptr);
3847 // Compute the constant that would happen if we truncated to SrcTy then
3848 // reextended to DstTy.
3850 ConstantFoldCastOperand(Instruction::Trunc
, C
, SrcTy
, Q
.DL
);
3851 assert(Trunc
&& "Constant-fold of ImmConstant should not fail");
3853 ConstantFoldCastOperand(CastInst::ZExt
, Trunc
, DstTy
, Q
.DL
);
3854 assert(RExt
&& "Constant-fold of ImmConstant should not fail");
3856 ConstantFoldCompareInstOperands(ICmpInst::ICMP_EQ
, RExt
, C
, Q
.DL
);
3857 assert(AnyEq
&& "Constant-fold of ImmConstant should not fail");
3859 // If the re-extended constant didn't change any of the elements then
3860 // this is effectively also a case of comparing two zero-extended
3862 if (AnyEq
->isAllOnesValue() && MaxRecurse
)
3863 if (Value
*V
= simplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred
),
3864 SrcOp
, Trunc
, Q
, MaxRecurse
- 1))
3867 // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
3868 // there. Use this to work out the result of the comparison.
3869 if (AnyEq
->isNullValue()) {
3872 llvm_unreachable("Unknown ICmp predicate!");
3874 case ICmpInst::ICMP_EQ
:
3875 case ICmpInst::ICMP_UGT
:
3876 case ICmpInst::ICMP_UGE
:
3877 return Constant::getNullValue(ITy
);
3879 case ICmpInst::ICMP_NE
:
3880 case ICmpInst::ICMP_ULT
:
3881 case ICmpInst::ICMP_ULE
:
3882 return Constant::getAllOnesValue(ITy
);
3884 // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
3885 // is non-negative then LHS <s RHS.
3886 case ICmpInst::ICMP_SGT
:
3887 case ICmpInst::ICMP_SGE
:
3888 return ConstantFoldCompareInstOperands(
3889 ICmpInst::ICMP_SLT
, C
, Constant::getNullValue(C
->getType()),
3891 case ICmpInst::ICMP_SLT
:
3892 case ICmpInst::ICMP_SLE
:
3893 return ConstantFoldCompareInstOperands(
3894 ICmpInst::ICMP_SGE
, C
, Constant::getNullValue(C
->getType()),
3901 if (isa
<SExtInst
>(LHS
)) {
3902 // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
3904 if (SExtInst
*RI
= dyn_cast
<SExtInst
>(RHS
)) {
3905 if (MaxRecurse
&& SrcTy
== RI
->getOperand(0)->getType())
3906 // Compare X and Y. Note that the predicate does not change.
3907 if (Value
*V
= simplifyICmpInst(Pred
, SrcOp
, RI
->getOperand(0), Q
,
3911 // Fold (sext X) uge (zext X), (sext X) sle (zext X) to true.
3912 else if (ZExtInst
*RI
= dyn_cast
<ZExtInst
>(RHS
)) {
3913 if (SrcOp
== RI
->getOperand(0)) {
3914 if (Pred
== ICmpInst::ICMP_UGE
|| Pred
== ICmpInst::ICMP_SLE
)
3915 return ConstantInt::getTrue(ITy
);
3916 if (Pred
== ICmpInst::ICMP_ULT
|| Pred
== ICmpInst::ICMP_SGT
)
3917 return ConstantInt::getFalse(ITy
);
3920 // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
3921 // too. If not, then try to deduce the result of the comparison.
3922 else if (match(RHS
, m_ImmConstant())) {
3923 Constant
*C
= cast
<Constant
>(RHS
);
3925 // Compute the constant that would happen if we truncated to SrcTy then
3926 // reextended to DstTy.
3928 ConstantFoldCastOperand(Instruction::Trunc
, C
, SrcTy
, Q
.DL
);
3929 assert(Trunc
&& "Constant-fold of ImmConstant should not fail");
3931 ConstantFoldCastOperand(CastInst::SExt
, Trunc
, DstTy
, Q
.DL
);
3932 assert(RExt
&& "Constant-fold of ImmConstant should not fail");
3934 ConstantFoldCompareInstOperands(ICmpInst::ICMP_EQ
, RExt
, C
, Q
.DL
);
3935 assert(AnyEq
&& "Constant-fold of ImmConstant should not fail");
3937 // If the re-extended constant didn't change then this is effectively
3938 // also a case of comparing two sign-extended values.
3939 if (AnyEq
->isAllOnesValue() && MaxRecurse
)
3941 simplifyICmpInst(Pred
, SrcOp
, Trunc
, Q
, MaxRecurse
- 1))
3944 // Otherwise the upper bits of LHS are all equal, while RHS has varying
3945 // bits there. Use this to work out the result of the comparison.
3946 if (AnyEq
->isNullValue()) {
3949 llvm_unreachable("Unknown ICmp predicate!");
3950 case ICmpInst::ICMP_EQ
:
3951 return Constant::getNullValue(ITy
);
3952 case ICmpInst::ICMP_NE
:
3953 return Constant::getAllOnesValue(ITy
);
3955 // If RHS is non-negative then LHS <s RHS. If RHS is negative then
3957 case ICmpInst::ICMP_SGT
:
3958 case ICmpInst::ICMP_SGE
:
3959 return ConstantFoldCompareInstOperands(
3960 ICmpInst::ICMP_SLT
, C
, Constant::getNullValue(C
->getType()),
3962 case ICmpInst::ICMP_SLT
:
3963 case ICmpInst::ICMP_SLE
:
3964 return ConstantFoldCompareInstOperands(
3965 ICmpInst::ICMP_SGE
, C
, Constant::getNullValue(C
->getType()),
3968 // If LHS is non-negative then LHS <u RHS. If LHS is negative then
3970 case ICmpInst::ICMP_UGT
:
3971 case ICmpInst::ICMP_UGE
:
3972 // Comparison is true iff the LHS <s 0.
3974 if (Value
*V
= simplifyICmpInst(ICmpInst::ICMP_SLT
, SrcOp
,
3975 Constant::getNullValue(SrcTy
), Q
,
3979 case ICmpInst::ICMP_ULT
:
3980 case ICmpInst::ICMP_ULE
:
3981 // Comparison is true iff the LHS >=s 0.
3983 if (Value
*V
= simplifyICmpInst(ICmpInst::ICMP_SGE
, SrcOp
,
3984 Constant::getNullValue(SrcTy
), Q
,
3994 // icmp eq|ne X, Y -> false|true if X != Y
3995 // This is potentially expensive, and we have already computedKnownBits for
3996 // compares with 0 above here, so only try this for a non-zero compare.
3997 if (ICmpInst::isEquality(Pred
) && !match(RHS
, m_Zero()) &&
3998 isKnownNonEqual(LHS
, RHS
, Q
)) {
3999 return Pred
== ICmpInst::ICMP_NE
? getTrue(ITy
) : getFalse(ITy
);
4002 if (Value
*V
= simplifyICmpWithBinOp(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4005 if (Value
*V
= simplifyICmpWithMinMax(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4008 if (Value
*V
= simplifyICmpWithIntrinsicOnLHS(Pred
, LHS
, RHS
))
4010 if (Value
*V
= simplifyICmpWithIntrinsicOnLHS(
4011 ICmpInst::getSwappedPredicate(Pred
), RHS
, LHS
))
4014 if (Value
*V
= simplifyICmpUsingMonotonicValues(Pred
, LHS
, RHS
))
4016 if (Value
*V
= simplifyICmpUsingMonotonicValues(
4017 ICmpInst::getSwappedPredicate(Pred
), RHS
, LHS
))
4020 if (Value
*V
= simplifyICmpWithDominatingAssume(Pred
, LHS
, RHS
, Q
))
4023 if (std::optional
<bool> Res
=
4024 isImpliedByDomCondition(Pred
, LHS
, RHS
, Q
.CxtI
, Q
.DL
))
4025 return ConstantInt::getBool(ITy
, *Res
);
4027 // Simplify comparisons of related pointers using a powerful, recursive
4028 // GEP-walk when we have target data available..
4029 if (LHS
->getType()->isPointerTy())
4030 if (auto *C
= computePointerICmp(Pred
, LHS
, RHS
, Q
))
4032 if (auto *CLHS
= dyn_cast
<PtrToIntOperator
>(LHS
))
4033 if (auto *CRHS
= dyn_cast
<PtrToIntOperator
>(RHS
))
4034 if (CLHS
->getPointerOperandType() == CRHS
->getPointerOperandType() &&
4035 Q
.DL
.getTypeSizeInBits(CLHS
->getPointerOperandType()) ==
4036 Q
.DL
.getTypeSizeInBits(CLHS
->getType()))
4037 if (auto *C
= computePointerICmp(Pred
, CLHS
->getPointerOperand(),
4038 CRHS
->getPointerOperand(), Q
))
4041 // If the comparison is with the result of a select instruction, check whether
4042 // comparing with either branch of the select always yields the same value.
4043 if (isa
<SelectInst
>(LHS
) || isa
<SelectInst
>(RHS
))
4044 if (Value
*V
= threadCmpOverSelect(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4047 // If the comparison is with the result of a phi instruction, check whether
4048 // doing the compare with each incoming phi value yields a common result.
4049 if (isa
<PHINode
>(LHS
) || isa
<PHINode
>(RHS
))
4050 if (Value
*V
= threadCmpOverPHI(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4056 Value
*llvm::simplifyICmpInst(CmpPredicate Predicate
, Value
*LHS
, Value
*RHS
,
4057 const SimplifyQuery
&Q
) {
4058 return ::simplifyICmpInst(Predicate
, LHS
, RHS
, Q
, RecursionLimit
);
4061 /// Given operands for an FCmpInst, see if we can fold the result.
4062 /// If not, this returns null.
4063 static Value
*simplifyFCmpInst(CmpPredicate Pred
, Value
*LHS
, Value
*RHS
,
4064 FastMathFlags FMF
, const SimplifyQuery
&Q
,
4065 unsigned MaxRecurse
) {
4066 assert(CmpInst::isFPPredicate(Pred
) && "Not an FP compare!");
4068 if (Constant
*CLHS
= dyn_cast
<Constant
>(LHS
)) {
4069 if (Constant
*CRHS
= dyn_cast
<Constant
>(RHS
))
4070 return ConstantFoldCompareInstOperands(Pred
, CLHS
, CRHS
, Q
.DL
, Q
.TLI
,
4073 // If we have a constant, make sure it is on the RHS.
4074 std::swap(LHS
, RHS
);
4075 Pred
= CmpInst::getSwappedPredicate(Pred
);
4078 // Fold trivial predicates.
4079 Type
*RetTy
= getCompareTy(LHS
);
4080 if (Pred
== FCmpInst::FCMP_FALSE
)
4081 return getFalse(RetTy
);
4082 if (Pred
== FCmpInst::FCMP_TRUE
)
4083 return getTrue(RetTy
);
4085 // fcmp pred x, poison and fcmp pred poison, x
4087 if (isa
<PoisonValue
>(LHS
) || isa
<PoisonValue
>(RHS
))
4088 return PoisonValue::get(RetTy
);
4090 // fcmp pred x, undef and fcmp pred undef, x
4091 // fold to true if unordered, false if ordered
4092 if (Q
.isUndefValue(LHS
) || Q
.isUndefValue(RHS
)) {
4093 // Choosing NaN for the undef will always make unordered comparison succeed
4094 // and ordered comparison fail.
4095 return ConstantInt::get(RetTy
, CmpInst::isUnordered(Pred
));
4098 // fcmp x,x -> true/false. Not all compares are foldable.
4100 if (CmpInst::isTrueWhenEqual(Pred
))
4101 return getTrue(RetTy
);
4102 if (CmpInst::isFalseWhenEqual(Pred
))
4103 return getFalse(RetTy
);
4106 // Fold (un)ordered comparison if we can determine there are no NaNs.
4108 // This catches the 2 variable input case, constants are handled below as a
4109 // class-like compare.
4110 if (Pred
== FCmpInst::FCMP_ORD
|| Pred
== FCmpInst::FCMP_UNO
) {
4111 KnownFPClass RHSClass
=
4112 computeKnownFPClass(RHS
, fcAllFlags
, /*Depth=*/0, Q
);
4113 KnownFPClass LHSClass
=
4114 computeKnownFPClass(LHS
, fcAllFlags
, /*Depth=*/0, Q
);
4117 (RHSClass
.isKnownNeverNaN() && LHSClass
.isKnownNeverNaN()))
4118 return ConstantInt::get(RetTy
, Pred
== FCmpInst::FCMP_ORD
);
4120 if (RHSClass
.isKnownAlwaysNaN() || LHSClass
.isKnownAlwaysNaN())
4121 return ConstantInt::get(RetTy
, Pred
== CmpInst::FCMP_UNO
);
4124 const APFloat
*C
= nullptr;
4125 match(RHS
, m_APFloatAllowPoison(C
));
4126 std::optional
<KnownFPClass
> FullKnownClassLHS
;
4128 // Lazily compute the possible classes for LHS. Avoid computing it twice if
4130 auto computeLHSClass
= [=, &FullKnownClassLHS
](FPClassTest InterestedFlags
=
4132 if (FullKnownClassLHS
)
4133 return *FullKnownClassLHS
;
4134 return computeKnownFPClass(LHS
, FMF
, InterestedFlags
, 0, Q
);
4138 // Fold out compares that express a class test.
4140 // FIXME: Should be able to perform folds without context
4141 // instruction. Always pass in the context function?
4143 const Function
*ParentF
= Q
.CxtI
->getFunction();
4144 auto [ClassVal
, ClassTest
] = fcmpToClassTest(Pred
, *ParentF
, LHS
, C
);
4146 FullKnownClassLHS
= computeLHSClass();
4147 if ((FullKnownClassLHS
->KnownFPClasses
& ClassTest
) == fcNone
)
4148 return getFalse(RetTy
);
4149 if ((FullKnownClassLHS
->KnownFPClasses
& ~ClassTest
) == fcNone
)
4150 return getTrue(RetTy
);
4154 // Handle fcmp with constant RHS.
4156 // TODO: If we always required a context function, we wouldn't need to
4157 // special case nans.
4159 return ConstantInt::get(RetTy
, CmpInst::isUnordered(Pred
));
4161 // TODO: Need version fcmpToClassTest which returns implied class when the
4162 // compare isn't a complete class test. e.g. > 1.0 implies fcPositive, but
4163 // isn't implementable as a class call.
4164 if (C
->isNegative() && !C
->isNegZero()) {
4165 FPClassTest Interested
= KnownFPClass::OrderedLessThanZeroMask
;
4167 // TODO: We can catch more cases by using a range check rather than
4168 // relying on CannotBeOrderedLessThanZero.
4170 case FCmpInst::FCMP_UGE
:
4171 case FCmpInst::FCMP_UGT
:
4172 case FCmpInst::FCMP_UNE
: {
4173 KnownFPClass KnownClass
= computeLHSClass(Interested
);
4175 // (X >= 0) implies (X > C) when (C < 0)
4176 if (KnownClass
.cannotBeOrderedLessThanZero())
4177 return getTrue(RetTy
);
4180 case FCmpInst::FCMP_OEQ
:
4181 case FCmpInst::FCMP_OLE
:
4182 case FCmpInst::FCMP_OLT
: {
4183 KnownFPClass KnownClass
= computeLHSClass(Interested
);
4185 // (X >= 0) implies !(X < C) when (C < 0)
4186 if (KnownClass
.cannotBeOrderedLessThanZero())
4187 return getFalse(RetTy
);
4194 // Check comparison of [minnum/maxnum with constant] with other constant.
4196 if ((match(LHS
, m_Intrinsic
<Intrinsic::minnum
>(m_Value(), m_APFloat(C2
))) &&
4198 (match(LHS
, m_Intrinsic
<Intrinsic::maxnum
>(m_Value(), m_APFloat(C2
))) &&
4201 cast
<IntrinsicInst
>(LHS
)->getIntrinsicID() == Intrinsic::maxnum
;
4202 // The ordered relationship and minnum/maxnum guarantee that we do not
4203 // have NaN constants, so ordered/unordered preds are handled the same.
4205 case FCmpInst::FCMP_OEQ
:
4206 case FCmpInst::FCMP_UEQ
:
4207 // minnum(X, LesserC) == C --> false
4208 // maxnum(X, GreaterC) == C --> false
4209 return getFalse(RetTy
);
4210 case FCmpInst::FCMP_ONE
:
4211 case FCmpInst::FCMP_UNE
:
4212 // minnum(X, LesserC) != C --> true
4213 // maxnum(X, GreaterC) != C --> true
4214 return getTrue(RetTy
);
4215 case FCmpInst::FCMP_OGE
:
4216 case FCmpInst::FCMP_UGE
:
4217 case FCmpInst::FCMP_OGT
:
4218 case FCmpInst::FCMP_UGT
:
4219 // minnum(X, LesserC) >= C --> false
4220 // minnum(X, LesserC) > C --> false
4221 // maxnum(X, GreaterC) >= C --> true
4222 // maxnum(X, GreaterC) > C --> true
4223 return ConstantInt::get(RetTy
, IsMaxNum
);
4224 case FCmpInst::FCMP_OLE
:
4225 case FCmpInst::FCMP_ULE
:
4226 case FCmpInst::FCMP_OLT
:
4227 case FCmpInst::FCMP_ULT
:
4228 // minnum(X, LesserC) <= C --> true
4229 // minnum(X, LesserC) < C --> true
4230 // maxnum(X, GreaterC) <= C --> false
4231 // maxnum(X, GreaterC) < C --> false
4232 return ConstantInt::get(RetTy
, !IsMaxNum
);
4234 // TRUE/FALSE/ORD/UNO should be handled before this.
4235 llvm_unreachable("Unexpected fcmp predicate");
4240 // TODO: Could fold this with above if there were a matcher which returned all
4241 // classes in a non-splat vector.
4242 if (match(RHS
, m_AnyZeroFP())) {
4244 case FCmpInst::FCMP_OGE
:
4245 case FCmpInst::FCMP_ULT
: {
4246 FPClassTest Interested
= KnownFPClass::OrderedLessThanZeroMask
;
4248 Interested
|= fcNan
;
4250 KnownFPClass Known
= computeLHSClass(Interested
);
4252 // Positive or zero X >= 0.0 --> true
4253 // Positive or zero X < 0.0 --> false
4254 if ((FMF
.noNaNs() || Known
.isKnownNeverNaN()) &&
4255 Known
.cannotBeOrderedLessThanZero())
4256 return Pred
== FCmpInst::FCMP_OGE
? getTrue(RetTy
) : getFalse(RetTy
);
4259 case FCmpInst::FCMP_UGE
:
4260 case FCmpInst::FCMP_OLT
: {
4261 FPClassTest Interested
= KnownFPClass::OrderedLessThanZeroMask
;
4262 KnownFPClass Known
= computeLHSClass(Interested
);
4264 // Positive or zero or nan X >= 0.0 --> true
4265 // Positive or zero or nan X < 0.0 --> false
4266 if (Known
.cannotBeOrderedLessThanZero())
4267 return Pred
== FCmpInst::FCMP_UGE
? getTrue(RetTy
) : getFalse(RetTy
);
4275 // If the comparison is with the result of a select instruction, check whether
4276 // comparing with either branch of the select always yields the same value.
4277 if (isa
<SelectInst
>(LHS
) || isa
<SelectInst
>(RHS
))
4278 if (Value
*V
= threadCmpOverSelect(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4281 // If the comparison is with the result of a phi instruction, check whether
4282 // doing the compare with each incoming phi value yields a common result.
4283 if (isa
<PHINode
>(LHS
) || isa
<PHINode
>(RHS
))
4284 if (Value
*V
= threadCmpOverPHI(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4290 Value
*llvm::simplifyFCmpInst(CmpPredicate Predicate
, Value
*LHS
, Value
*RHS
,
4291 FastMathFlags FMF
, const SimplifyQuery
&Q
) {
4292 return ::simplifyFCmpInst(Predicate
, LHS
, RHS
, FMF
, Q
, RecursionLimit
);
4295 static Value
*simplifyWithOpsReplaced(Value
*V
,
4296 ArrayRef
<std::pair
<Value
*, Value
*>> Ops
,
4297 const SimplifyQuery
&Q
,
4298 bool AllowRefinement
,
4299 SmallVectorImpl
<Instruction
*> *DropFlags
,
4300 unsigned MaxRecurse
) {
4301 assert((AllowRefinement
|| !Q
.CanUseUndef
) &&
4302 "If AllowRefinement=false then CanUseUndef=false");
4303 for (const auto &OpAndRepOp
: Ops
) {
4304 // We cannot replace a constant, and shouldn't even try.
4305 if (isa
<Constant
>(OpAndRepOp
.first
))
4308 // Trivial replacement.
4309 if (V
== OpAndRepOp
.first
)
4310 return OpAndRepOp
.second
;
4316 auto *I
= dyn_cast
<Instruction
>(V
);
4320 // The arguments of a phi node might refer to a value from a previous
4322 if (isa
<PHINode
>(I
))
4325 // Don't fold away llvm.is.constant checks based on assumptions.
4326 if (match(I
, m_Intrinsic
<Intrinsic::is_constant
>()))
4329 // Don't simplify freeze.
4330 if (isa
<FreezeInst
>(I
))
4333 for (const auto &OpAndRepOp
: Ops
) {
4334 // For vector types, the simplification must hold per-lane, so forbid
4335 // potentially cross-lane operations like shufflevector.
4336 if (OpAndRepOp
.first
->getType()->isVectorTy() &&
4337 !isNotCrossLaneOperation(I
))
4341 // Replace Op with RepOp in instruction operands.
4342 SmallVector
<Value
*, 8> NewOps
;
4343 bool AnyReplaced
= false;
4344 for (Value
*InstOp
: I
->operands()) {
4345 if (Value
*NewInstOp
= simplifyWithOpsReplaced(
4346 InstOp
, Ops
, Q
, AllowRefinement
, DropFlags
, MaxRecurse
)) {
4347 NewOps
.push_back(NewInstOp
);
4348 AnyReplaced
= InstOp
!= NewInstOp
;
4350 NewOps
.push_back(InstOp
);
4353 // Bail out if any operand is undef and SimplifyQuery disables undef
4354 // simplification. Constant folding currently doesn't respect this option.
4355 if (isa
<UndefValue
>(NewOps
.back()) && !Q
.CanUseUndef
)
4362 if (!AllowRefinement
) {
4363 // General InstSimplify functions may refine the result, e.g. by returning
4364 // a constant for a potentially poison value. To avoid this, implement only
4365 // a few non-refining but profitable transforms here.
4367 if (auto *BO
= dyn_cast
<BinaryOperator
>(I
)) {
4368 unsigned Opcode
= BO
->getOpcode();
4369 // id op x -> x, x op id -> x
4370 // Exclude floats, because x op id may produce a different NaN value.
4371 if (!BO
->getType()->isFPOrFPVectorTy()) {
4372 if (NewOps
[0] == ConstantExpr::getBinOpIdentity(Opcode
, I
->getType()))
4374 if (NewOps
[1] == ConstantExpr::getBinOpIdentity(Opcode
, I
->getType(),
4379 // x & x -> x, x | x -> x
4380 if ((Opcode
== Instruction::And
|| Opcode
== Instruction::Or
) &&
4381 NewOps
[0] == NewOps
[1]) {
4382 // or disjoint x, x results in poison.
4383 if (auto *PDI
= dyn_cast
<PossiblyDisjointInst
>(BO
)) {
4384 if (PDI
->isDisjoint()) {
4387 DropFlags
->push_back(BO
);
4393 // x - x -> 0, x ^ x -> 0. This is non-refining, because x is non-poison
4394 // by assumption and this case never wraps, so nowrap flags can be
4396 if ((Opcode
== Instruction::Sub
|| Opcode
== Instruction::Xor
) &&
4397 NewOps
[0] == NewOps
[1] &&
4398 any_of(Ops
, [=](const auto &Rep
) { return NewOps
[0] == Rep
.second
; }))
4399 return Constant::getNullValue(I
->getType());
4401 // If we are substituting an absorber constant into a binop and extra
4402 // poison can't leak if we remove the select -- because both operands of
4403 // the binop are based on the same value -- then it may be safe to replace
4404 // the value with the absorber constant. Examples:
4405 // (Op == 0) ? 0 : (Op & -Op) --> Op & -Op
4406 // (Op == 0) ? 0 : (Op * (binop Op, C)) --> Op * (binop Op, C)
4407 // (Op == -1) ? -1 : (Op | (binop C, Op) --> Op | (binop C, Op)
4408 Constant
*Absorber
= ConstantExpr::getBinOpAbsorber(Opcode
, I
->getType());
4409 if ((NewOps
[0] == Absorber
|| NewOps
[1] == Absorber
) &&
4411 [=](const auto &Rep
) { return impliesPoison(BO
, Rep
.first
); }))
4415 if (isa
<GetElementPtrInst
>(I
)) {
4416 // getelementptr x, 0 -> x.
4417 // This never returns poison, even if inbounds is set.
4418 if (NewOps
.size() == 2 && match(NewOps
[1], m_Zero()))
4422 // The simplification queries below may return the original value. Consider:
4423 // %div = udiv i32 %arg, %arg2
4424 // %mul = mul nsw i32 %div, %arg2
4425 // %cmp = icmp eq i32 %mul, %arg
4426 // %sel = select i1 %cmp, i32 %div, i32 undef
4427 // Replacing %arg by %mul, %div becomes "udiv i32 %mul, %arg2", which
4428 // simplifies back to %arg. This can only happen because %mul does not
4429 // dominate %div. To ensure a consistent return value contract, we make sure
4430 // that this case returns nullptr as well.
4431 auto PreventSelfSimplify
= [V
](Value
*Simplified
) {
4432 return Simplified
!= V
? Simplified
: nullptr;
4435 return PreventSelfSimplify(
4436 ::simplifyInstructionWithOperands(I
, NewOps
, Q
, MaxRecurse
));
4439 // If all operands are constant after substituting Op for RepOp then we can
4440 // constant fold the instruction.
4441 SmallVector
<Constant
*, 8> ConstOps
;
4442 for (Value
*NewOp
: NewOps
) {
4443 if (Constant
*ConstOp
= dyn_cast
<Constant
>(NewOp
))
4444 ConstOps
.push_back(ConstOp
);
4450 // %cmp = icmp eq i32 %x, 2147483647
4451 // %add = add nsw i32 %x, 1
4452 // %sel = select i1 %cmp, i32 -2147483648, i32 %add
4454 // We can't replace %sel with %add unless we strip away the flags (which
4455 // will be done in InstCombine).
4456 // TODO: This may be unsound, because it only catches some forms of
4458 if (!AllowRefinement
) {
4459 if (canCreatePoison(cast
<Operator
>(I
), !DropFlags
)) {
4460 // abs cannot create poison if the value is known to never be int_min.
4461 if (auto *II
= dyn_cast
<IntrinsicInst
>(I
);
4462 II
&& II
->getIntrinsicID() == Intrinsic::abs
) {
4463 if (!ConstOps
[0]->isNotMinSignedValue())
4468 Constant
*Res
= ConstantFoldInstOperands(I
, ConstOps
, Q
.DL
, Q
.TLI
,
4469 /*AllowNonDeterministic=*/false);
4470 if (DropFlags
&& Res
&& I
->hasPoisonGeneratingAnnotations())
4471 DropFlags
->push_back(I
);
4475 return ConstantFoldInstOperands(I
, ConstOps
, Q
.DL
, Q
.TLI
,
4476 /*AllowNonDeterministic=*/false);
4479 static Value
*simplifyWithOpReplaced(Value
*V
, Value
*Op
, Value
*RepOp
,
4480 const SimplifyQuery
&Q
,
4481 bool AllowRefinement
,
4482 SmallVectorImpl
<Instruction
*> *DropFlags
,
4483 unsigned MaxRecurse
) {
4484 return simplifyWithOpsReplaced(V
, {{Op
, RepOp
}}, Q
, AllowRefinement
,
4485 DropFlags
, MaxRecurse
);
4488 Value
*llvm::simplifyWithOpReplaced(Value
*V
, Value
*Op
, Value
*RepOp
,
4489 const SimplifyQuery
&Q
,
4490 bool AllowRefinement
,
4491 SmallVectorImpl
<Instruction
*> *DropFlags
) {
4492 // If refinement is disabled, also disable undef simplifications (which are
4493 // always refinements) in SimplifyQuery.
4494 if (!AllowRefinement
)
4495 return ::simplifyWithOpReplaced(V
, Op
, RepOp
, Q
.getWithoutUndef(),
4496 AllowRefinement
, DropFlags
, RecursionLimit
);
4497 return ::simplifyWithOpReplaced(V
, Op
, RepOp
, Q
, AllowRefinement
, DropFlags
,
4501 /// Try to simplify a select instruction when its condition operand is an
4502 /// integer comparison where one operand of the compare is a constant.
4503 static Value
*simplifySelectBitTest(Value
*TrueVal
, Value
*FalseVal
, Value
*X
,
4504 const APInt
*Y
, bool TrueWhenUnset
) {
4507 // (X & Y) == 0 ? X & ~Y : X --> X
4508 // (X & Y) != 0 ? X & ~Y : X --> X & ~Y
4509 if (FalseVal
== X
&& match(TrueVal
, m_And(m_Specific(X
), m_APInt(C
))) &&
4511 return TrueWhenUnset
? FalseVal
: TrueVal
;
4513 // (X & Y) == 0 ? X : X & ~Y --> X & ~Y
4514 // (X & Y) != 0 ? X : X & ~Y --> X
4515 if (TrueVal
== X
&& match(FalseVal
, m_And(m_Specific(X
), m_APInt(C
))) &&
4517 return TrueWhenUnset
? FalseVal
: TrueVal
;
4519 if (Y
->isPowerOf2()) {
4520 // (X & Y) == 0 ? X | Y : X --> X | Y
4521 // (X & Y) != 0 ? X | Y : X --> X
4522 if (FalseVal
== X
&& match(TrueVal
, m_Or(m_Specific(X
), m_APInt(C
))) &&
4524 // We can't return the or if it has the disjoint flag.
4525 if (TrueWhenUnset
&& cast
<PossiblyDisjointInst
>(TrueVal
)->isDisjoint())
4527 return TrueWhenUnset
? TrueVal
: FalseVal
;
4530 // (X & Y) == 0 ? X : X | Y --> X
4531 // (X & Y) != 0 ? X : X | Y --> X | Y
4532 if (TrueVal
== X
&& match(FalseVal
, m_Or(m_Specific(X
), m_APInt(C
))) &&
4534 // We can't return the or if it has the disjoint flag.
4535 if (!TrueWhenUnset
&& cast
<PossiblyDisjointInst
>(FalseVal
)->isDisjoint())
4537 return TrueWhenUnset
? TrueVal
: FalseVal
;
4544 static Value
*simplifyCmpSelOfMaxMin(Value
*CmpLHS
, Value
*CmpRHS
,
4545 CmpPredicate Pred
, Value
*TVal
,
4547 // Canonicalize common cmp+sel operand as CmpLHS.
4548 if (CmpRHS
== TVal
|| CmpRHS
== FVal
) {
4549 std::swap(CmpLHS
, CmpRHS
);
4550 Pred
= ICmpInst::getSwappedPredicate(Pred
);
4553 // Canonicalize common cmp+sel operand as TVal.
4554 if (CmpLHS
== FVal
) {
4555 std::swap(TVal
, FVal
);
4556 Pred
= ICmpInst::getInversePredicate(Pred
);
4559 // A vector select may be shuffling together elements that are equivalent
4560 // based on the max/min/select relationship.
4561 Value
*X
= CmpLHS
, *Y
= CmpRHS
;
4562 bool PeekedThroughSelectShuffle
= false;
4563 auto *Shuf
= dyn_cast
<ShuffleVectorInst
>(FVal
);
4564 if (Shuf
&& Shuf
->isSelect()) {
4565 if (Shuf
->getOperand(0) == Y
)
4566 FVal
= Shuf
->getOperand(1);
4567 else if (Shuf
->getOperand(1) == Y
)
4568 FVal
= Shuf
->getOperand(0);
4571 PeekedThroughSelectShuffle
= true;
4574 // (X pred Y) ? X : max/min(X, Y)
4575 auto *MMI
= dyn_cast
<MinMaxIntrinsic
>(FVal
);
4576 if (!MMI
|| TVal
!= X
||
4577 !match(FVal
, m_c_MaxOrMin(m_Specific(X
), m_Specific(Y
))))
4580 // (X > Y) ? X : max(X, Y) --> max(X, Y)
4581 // (X >= Y) ? X : max(X, Y) --> max(X, Y)
4582 // (X < Y) ? X : min(X, Y) --> min(X, Y)
4583 // (X <= Y) ? X : min(X, Y) --> min(X, Y)
4585 // The equivalence allows a vector select (shuffle) of max/min and Y. Ex:
4586 // (X > Y) ? X : (Z ? max(X, Y) : Y)
4587 // If Z is true, this reduces as above, and if Z is false:
4588 // (X > Y) ? X : Y --> max(X, Y)
4589 ICmpInst::Predicate MMPred
= MMI
->getPredicate();
4590 if (MMPred
== CmpInst::getStrictPredicate(Pred
))
4593 // Other transforms are not valid with a shuffle.
4594 if (PeekedThroughSelectShuffle
)
4597 // (X == Y) ? X : max/min(X, Y) --> max/min(X, Y)
4598 if (Pred
== CmpInst::ICMP_EQ
)
4601 // (X != Y) ? X : max/min(X, Y) --> X
4602 if (Pred
== CmpInst::ICMP_NE
)
4605 // (X < Y) ? X : max(X, Y) --> X
4606 // (X <= Y) ? X : max(X, Y) --> X
4607 // (X > Y) ? X : min(X, Y) --> X
4608 // (X >= Y) ? X : min(X, Y) --> X
4609 ICmpInst::Predicate InvPred
= CmpInst::getInversePredicate(Pred
);
4610 if (MMPred
== CmpInst::getStrictPredicate(InvPred
))
4616 /// An alternative way to test if a bit is set or not.
4617 /// uses e.g. sgt/slt or trunc instead of eq/ne.
4618 static Value
*simplifySelectWithBitTest(Value
*CondVal
, Value
*TrueVal
,
4620 if (auto Res
= decomposeBitTest(CondVal
))
4621 return simplifySelectBitTest(TrueVal
, FalseVal
, Res
->X
, &Res
->Mask
,
4622 Res
->Pred
== ICmpInst::ICMP_EQ
);
4627 /// Try to simplify a select instruction when its condition operand is an
4628 /// integer equality or floating-point equivalence comparison.
4629 static Value
*simplifySelectWithEquivalence(
4630 ArrayRef
<std::pair
<Value
*, Value
*>> Replacements
, Value
*TrueVal
,
4631 Value
*FalseVal
, const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
4632 Value
*SimplifiedFalseVal
=
4633 simplifyWithOpsReplaced(FalseVal
, Replacements
, Q
.getWithoutUndef(),
4634 /* AllowRefinement */ false,
4635 /* DropFlags */ nullptr, MaxRecurse
);
4636 if (!SimplifiedFalseVal
)
4637 SimplifiedFalseVal
= FalseVal
;
4639 Value
*SimplifiedTrueVal
=
4640 simplifyWithOpsReplaced(TrueVal
, Replacements
, Q
,
4641 /* AllowRefinement */ true,
4642 /* DropFlags */ nullptr, MaxRecurse
);
4643 if (!SimplifiedTrueVal
)
4644 SimplifiedTrueVal
= TrueVal
;
4646 if (SimplifiedFalseVal
== SimplifiedTrueVal
)
4652 /// Try to simplify a select instruction when its condition operand is an
4653 /// integer comparison.
4654 static Value
*simplifySelectWithICmpCond(Value
*CondVal
, Value
*TrueVal
,
4656 const SimplifyQuery
&Q
,
4657 unsigned MaxRecurse
) {
4659 Value
*CmpLHS
, *CmpRHS
;
4660 if (!match(CondVal
, m_ICmp(Pred
, m_Value(CmpLHS
), m_Value(CmpRHS
))))
4663 if (Value
*V
= simplifyCmpSelOfMaxMin(CmpLHS
, CmpRHS
, Pred
, TrueVal
, FalseVal
))
4666 // Canonicalize ne to eq predicate.
4667 if (Pred
== ICmpInst::ICMP_NE
) {
4668 Pred
= ICmpInst::ICMP_EQ
;
4669 std::swap(TrueVal
, FalseVal
);
4672 // Check for integer min/max with a limit constant:
4673 // X > MIN_INT ? X : MIN_INT --> X
4674 // X < MAX_INT ? X : MAX_INT --> X
4675 if (TrueVal
->getType()->isIntOrIntVectorTy()) {
4677 SelectPatternFlavor SPF
=
4678 matchDecomposedSelectPattern(cast
<ICmpInst
>(CondVal
), TrueVal
, FalseVal
,
4681 if (SelectPatternResult::isMinOrMax(SPF
) && Pred
== getMinMaxPred(SPF
)) {
4682 APInt LimitC
= getMinMaxLimit(getInverseMinMaxFlavor(SPF
),
4683 X
->getType()->getScalarSizeInBits());
4684 if (match(Y
, m_SpecificInt(LimitC
)))
4689 if (Pred
== ICmpInst::ICMP_EQ
&& match(CmpRHS
, m_Zero())) {
4692 if (match(CmpLHS
, m_And(m_Value(X
), m_APInt(Y
))))
4693 if (Value
*V
= simplifySelectBitTest(TrueVal
, FalseVal
, X
, Y
,
4694 /*TrueWhenUnset=*/true))
4697 // Test for a bogus zero-shift-guard-op around funnel-shift or rotate.
4699 auto isFsh
= m_CombineOr(m_FShl(m_Value(X
), m_Value(), m_Value(ShAmt
)),
4700 m_FShr(m_Value(), m_Value(X
), m_Value(ShAmt
)));
4701 // (ShAmt == 0) ? fshl(X, *, ShAmt) : X --> X
4702 // (ShAmt == 0) ? fshr(*, X, ShAmt) : X --> X
4703 if (match(TrueVal
, isFsh
) && FalseVal
== X
&& CmpLHS
== ShAmt
)
4706 // Test for a zero-shift-guard-op around rotates. These are used to
4707 // avoid UB from oversized shifts in raw IR rotate patterns, but the
4708 // intrinsics do not have that problem.
4709 // We do not allow this transform for the general funnel shift case because
4710 // that would not preserve the poison safety of the original code.
4712 m_CombineOr(m_FShl(m_Value(X
), m_Deferred(X
), m_Value(ShAmt
)),
4713 m_FShr(m_Value(X
), m_Deferred(X
), m_Value(ShAmt
)));
4714 // (ShAmt == 0) ? X : fshl(X, X, ShAmt) --> fshl(X, X, ShAmt)
4715 // (ShAmt == 0) ? X : fshr(X, X, ShAmt) --> fshr(X, X, ShAmt)
4716 if (match(FalseVal
, isRotate
) && TrueVal
== X
&& CmpLHS
== ShAmt
&&
4717 Pred
== ICmpInst::ICMP_EQ
)
4720 // X == 0 ? abs(X) : -abs(X) --> -abs(X)
4721 // X == 0 ? -abs(X) : abs(X) --> abs(X)
4722 if (match(TrueVal
, m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
))) &&
4723 match(FalseVal
, m_Neg(m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
)))))
4726 m_Neg(m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
)))) &&
4727 match(FalseVal
, m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
))))
4731 // If we have a scalar equality comparison, then we know the value in one of
4732 // the arms of the select. See if substituting this value into the arm and
4733 // simplifying the result yields the same value as the other arm.
4734 if (Pred
== ICmpInst::ICMP_EQ
) {
4735 if (CmpLHS
->getType()->isIntOrIntVectorTy() ||
4736 canReplacePointersIfEqual(CmpLHS
, CmpRHS
, Q
.DL
))
4737 if (Value
*V
= simplifySelectWithEquivalence({{CmpLHS
, CmpRHS
}}, TrueVal
,
4738 FalseVal
, Q
, MaxRecurse
))
4740 if (CmpLHS
->getType()->isIntOrIntVectorTy() ||
4741 canReplacePointersIfEqual(CmpRHS
, CmpLHS
, Q
.DL
))
4742 if (Value
*V
= simplifySelectWithEquivalence({{CmpRHS
, CmpLHS
}}, TrueVal
,
4743 FalseVal
, Q
, MaxRecurse
))
4748 // select((X | Y) == 0 ? X : 0) --> 0 (commuted 2 ways)
4749 if (match(CmpLHS
, m_Or(m_Value(X
), m_Value(Y
))) &&
4750 match(CmpRHS
, m_Zero())) {
4751 // (X | Y) == 0 implies X == 0 and Y == 0.
4752 if (Value
*V
= simplifySelectWithEquivalence(
4753 {{X
, CmpRHS
}, {Y
, CmpRHS
}}, TrueVal
, FalseVal
, Q
, MaxRecurse
))
4757 // select((X & Y) == -1 ? X : -1) --> -1 (commuted 2 ways)
4758 if (match(CmpLHS
, m_And(m_Value(X
), m_Value(Y
))) &&
4759 match(CmpRHS
, m_AllOnes())) {
4760 // (X & Y) == -1 implies X == -1 and Y == -1.
4761 if (Value
*V
= simplifySelectWithEquivalence(
4762 {{X
, CmpRHS
}, {Y
, CmpRHS
}}, TrueVal
, FalseVal
, Q
, MaxRecurse
))
4770 /// Try to simplify a select instruction when its condition operand is a
4771 /// floating-point comparison.
4772 static Value
*simplifySelectWithFCmp(Value
*Cond
, Value
*T
, Value
*F
,
4773 const SimplifyQuery
&Q
,
4774 unsigned MaxRecurse
) {
4776 Value
*CmpLHS
, *CmpRHS
;
4777 if (!match(Cond
, m_FCmp(Pred
, m_Value(CmpLHS
), m_Value(CmpRHS
))))
4779 FCmpInst
*I
= cast
<FCmpInst
>(Cond
);
4781 bool IsEquiv
= I
->isEquivalence();
4782 if (I
->isEquivalence(/*Invert=*/true)) {
4784 Pred
= FCmpInst::getInversePredicate(Pred
);
4788 // This transforms is safe if at least one operand is known to not be zero.
4789 // Otherwise, the select can change the sign of a zero operand.
4791 if (Value
*V
= simplifySelectWithEquivalence({{CmpLHS
, CmpRHS
}}, T
, F
, Q
,
4794 if (Value
*V
= simplifySelectWithEquivalence({{CmpRHS
, CmpLHS
}}, T
, F
, Q
,
4799 // Canonicalize CmpLHS to be T, and CmpRHS to be F, if they're swapped.
4800 if (CmpLHS
== F
&& CmpRHS
== T
)
4801 std::swap(CmpLHS
, CmpRHS
);
4803 if (CmpLHS
!= T
|| CmpRHS
!= F
)
4806 // This transform is also safe if we do not have (do not care about) -0.0.
4807 if (Q
.CxtI
&& isa
<FPMathOperator
>(Q
.CxtI
) && Q
.CxtI
->hasNoSignedZeros()) {
4808 // (T == F) ? T : F --> F
4809 if (Pred
== FCmpInst::FCMP_OEQ
)
4812 // (T != F) ? T : F --> T
4813 if (Pred
== FCmpInst::FCMP_UNE
)
4820 /// Given operands for a SelectInst, see if we can fold the result.
4821 /// If not, this returns null.
4822 static Value
*simplifySelectInst(Value
*Cond
, Value
*TrueVal
, Value
*FalseVal
,
4823 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
4824 if (auto *CondC
= dyn_cast
<Constant
>(Cond
)) {
4825 if (auto *TrueC
= dyn_cast
<Constant
>(TrueVal
))
4826 if (auto *FalseC
= dyn_cast
<Constant
>(FalseVal
))
4827 if (Constant
*C
= ConstantFoldSelectInstruction(CondC
, TrueC
, FalseC
))
4830 // select poison, X, Y -> poison
4831 if (isa
<PoisonValue
>(CondC
))
4832 return PoisonValue::get(TrueVal
->getType());
4834 // select undef, X, Y -> X or Y
4835 if (Q
.isUndefValue(CondC
))
4836 return isa
<Constant
>(FalseVal
) ? FalseVal
: TrueVal
;
4838 // select true, X, Y --> X
4839 // select false, X, Y --> Y
4840 // For vectors, allow undef/poison elements in the condition to match the
4841 // defined elements, so we can eliminate the select.
4842 if (match(CondC
, m_One()))
4844 if (match(CondC
, m_Zero()))
4848 assert(Cond
->getType()->isIntOrIntVectorTy(1) &&
4849 "Select must have bool or bool vector condition");
4850 assert(TrueVal
->getType() == FalseVal
->getType() &&
4851 "Select must have same types for true/false ops");
4853 if (Cond
->getType() == TrueVal
->getType()) {
4854 // select i1 Cond, i1 true, i1 false --> i1 Cond
4855 if (match(TrueVal
, m_One()) && match(FalseVal
, m_ZeroInt()))
4858 // (X && Y) ? X : Y --> Y (commuted 2 ways)
4859 if (match(Cond
, m_c_LogicalAnd(m_Specific(TrueVal
), m_Specific(FalseVal
))))
4862 // (X || Y) ? X : Y --> X (commuted 2 ways)
4863 if (match(Cond
, m_c_LogicalOr(m_Specific(TrueVal
), m_Specific(FalseVal
))))
4866 // (X || Y) ? false : X --> false (commuted 2 ways)
4867 if (match(Cond
, m_c_LogicalOr(m_Specific(FalseVal
), m_Value())) &&
4868 match(TrueVal
, m_ZeroInt()))
4869 return ConstantInt::getFalse(Cond
->getType());
4871 // Match patterns that end in logical-and.
4872 if (match(FalseVal
, m_ZeroInt())) {
4873 // !(X || Y) && X --> false (commuted 2 ways)
4874 if (match(Cond
, m_Not(m_c_LogicalOr(m_Specific(TrueVal
), m_Value()))))
4875 return ConstantInt::getFalse(Cond
->getType());
4876 // X && !(X || Y) --> false (commuted 2 ways)
4877 if (match(TrueVal
, m_Not(m_c_LogicalOr(m_Specific(Cond
), m_Value()))))
4878 return ConstantInt::getFalse(Cond
->getType());
4880 // (X || Y) && Y --> Y (commuted 2 ways)
4881 if (match(Cond
, m_c_LogicalOr(m_Specific(TrueVal
), m_Value())))
4883 // Y && (X || Y) --> Y (commuted 2 ways)
4884 if (match(TrueVal
, m_c_LogicalOr(m_Specific(Cond
), m_Value())))
4887 // (X || Y) && (X || !Y) --> X (commuted 8 ways)
4889 if (match(Cond
, m_c_LogicalOr(m_Value(X
), m_Not(m_Value(Y
)))) &&
4890 match(TrueVal
, m_c_LogicalOr(m_Specific(X
), m_Specific(Y
))))
4892 if (match(TrueVal
, m_c_LogicalOr(m_Value(X
), m_Not(m_Value(Y
)))) &&
4893 match(Cond
, m_c_LogicalOr(m_Specific(X
), m_Specific(Y
))))
4897 // Match patterns that end in logical-or.
4898 if (match(TrueVal
, m_One())) {
4899 // !(X && Y) || X --> true (commuted 2 ways)
4900 if (match(Cond
, m_Not(m_c_LogicalAnd(m_Specific(FalseVal
), m_Value()))))
4901 return ConstantInt::getTrue(Cond
->getType());
4902 // X || !(X && Y) --> true (commuted 2 ways)
4903 if (match(FalseVal
, m_Not(m_c_LogicalAnd(m_Specific(Cond
), m_Value()))))
4904 return ConstantInt::getTrue(Cond
->getType());
4906 // (X && Y) || Y --> Y (commuted 2 ways)
4907 if (match(Cond
, m_c_LogicalAnd(m_Specific(FalseVal
), m_Value())))
4909 // Y || (X && Y) --> Y (commuted 2 ways)
4910 if (match(FalseVal
, m_c_LogicalAnd(m_Specific(Cond
), m_Value())))
4915 // select ?, X, X -> X
4916 if (TrueVal
== FalseVal
)
4919 if (Cond
== TrueVal
) {
4920 // select i1 X, i1 X, i1 false --> X (logical-and)
4921 if (match(FalseVal
, m_ZeroInt()))
4923 // select i1 X, i1 X, i1 true --> true
4924 if (match(FalseVal
, m_One()))
4925 return ConstantInt::getTrue(Cond
->getType());
4927 if (Cond
== FalseVal
) {
4928 // select i1 X, i1 true, i1 X --> X (logical-or)
4929 if (match(TrueVal
, m_One()))
4931 // select i1 X, i1 false, i1 X --> false
4932 if (match(TrueVal
, m_ZeroInt()))
4933 return ConstantInt::getFalse(Cond
->getType());
4936 // If the true or false value is poison, we can fold to the other value.
4937 // If the true or false value is undef, we can fold to the other value as
4938 // long as the other value isn't poison.
4939 // select ?, poison, X -> X
4940 // select ?, undef, X -> X
4941 if (isa
<PoisonValue
>(TrueVal
) ||
4942 (Q
.isUndefValue(TrueVal
) && impliesPoison(FalseVal
, Cond
)))
4944 // select ?, X, poison -> X
4945 // select ?, X, undef -> X
4946 if (isa
<PoisonValue
>(FalseVal
) ||
4947 (Q
.isUndefValue(FalseVal
) && impliesPoison(TrueVal
, Cond
)))
4950 // Deal with partial undef vector constants: select ?, VecC, VecC' --> VecC''
4951 Constant
*TrueC
, *FalseC
;
4952 if (isa
<FixedVectorType
>(TrueVal
->getType()) &&
4953 match(TrueVal
, m_Constant(TrueC
)) &&
4954 match(FalseVal
, m_Constant(FalseC
))) {
4956 cast
<FixedVectorType
>(TrueC
->getType())->getNumElements();
4957 SmallVector
<Constant
*, 16> NewC
;
4958 for (unsigned i
= 0; i
!= NumElts
; ++i
) {
4959 // Bail out on incomplete vector constants.
4960 Constant
*TEltC
= TrueC
->getAggregateElement(i
);
4961 Constant
*FEltC
= FalseC
->getAggregateElement(i
);
4962 if (!TEltC
|| !FEltC
)
4965 // If the elements match (undef or not), that value is the result. If only
4966 // one element is undef, choose the defined element as the safe result.
4968 NewC
.push_back(TEltC
);
4969 else if (isa
<PoisonValue
>(TEltC
) ||
4970 (Q
.isUndefValue(TEltC
) && isGuaranteedNotToBePoison(FEltC
)))
4971 NewC
.push_back(FEltC
);
4972 else if (isa
<PoisonValue
>(FEltC
) ||
4973 (Q
.isUndefValue(FEltC
) && isGuaranteedNotToBePoison(TEltC
)))
4974 NewC
.push_back(TEltC
);
4978 if (NewC
.size() == NumElts
)
4979 return ConstantVector::get(NewC
);
4983 simplifySelectWithICmpCond(Cond
, TrueVal
, FalseVal
, Q
, MaxRecurse
))
4986 if (Value
*V
= simplifySelectWithBitTest(Cond
, TrueVal
, FalseVal
))
4989 if (Value
*V
= simplifySelectWithFCmp(Cond
, TrueVal
, FalseVal
, Q
, MaxRecurse
))
4992 std::optional
<bool> Imp
= isImpliedByDomCondition(Cond
, Q
.CxtI
, Q
.DL
);
4994 return *Imp
? TrueVal
: FalseVal
;
4999 Value
*llvm::simplifySelectInst(Value
*Cond
, Value
*TrueVal
, Value
*FalseVal
,
5000 const SimplifyQuery
&Q
) {
5001 return ::simplifySelectInst(Cond
, TrueVal
, FalseVal
, Q
, RecursionLimit
);
5004 /// Given operands for an GetElementPtrInst, see if we can fold the result.
5005 /// If not, this returns null.
5006 static Value
*simplifyGEPInst(Type
*SrcTy
, Value
*Ptr
,
5007 ArrayRef
<Value
*> Indices
, GEPNoWrapFlags NW
,
5008 const SimplifyQuery
&Q
, unsigned) {
5009 // The type of the GEP pointer operand.
5011 cast
<PointerType
>(Ptr
->getType()->getScalarType())->getAddressSpace();
5013 // getelementptr P -> P.
5014 if (Indices
.empty())
5017 // Compute the (pointer) type returned by the GEP instruction.
5018 Type
*LastType
= GetElementPtrInst::getIndexedType(SrcTy
, Indices
);
5019 Type
*GEPTy
= Ptr
->getType();
5020 if (!GEPTy
->isVectorTy()) {
5021 for (Value
*Op
: Indices
) {
5022 // If one of the operands is a vector, the result type is a vector of
5023 // pointers. All vector operands must have the same number of elements.
5024 if (VectorType
*VT
= dyn_cast
<VectorType
>(Op
->getType())) {
5025 GEPTy
= VectorType::get(GEPTy
, VT
->getElementCount());
5031 // All-zero GEP is a no-op, unless it performs a vector splat.
5032 if (Ptr
->getType() == GEPTy
&&
5033 all_of(Indices
, [](const auto *V
) { return match(V
, m_Zero()); }))
5036 // getelementptr poison, idx -> poison
5037 // getelementptr baseptr, poison -> poison
5038 if (isa
<PoisonValue
>(Ptr
) ||
5039 any_of(Indices
, [](const auto *V
) { return isa
<PoisonValue
>(V
); }))
5040 return PoisonValue::get(GEPTy
);
5042 // getelementptr undef, idx -> undef
5043 if (Q
.isUndefValue(Ptr
))
5044 return UndefValue::get(GEPTy
);
5046 bool IsScalableVec
=
5047 SrcTy
->isScalableTy() || any_of(Indices
, [](const Value
*V
) {
5048 return isa
<ScalableVectorType
>(V
->getType());
5051 if (Indices
.size() == 1) {
5053 if (!IsScalableVec
&& Ty
->isSized()) {
5056 uint64_t TyAllocSize
= Q
.DL
.getTypeAllocSize(Ty
);
5057 // getelementptr P, N -> P if P points to a type of zero size.
5058 if (TyAllocSize
== 0 && Ptr
->getType() == GEPTy
)
5061 // The following transforms are only safe if the ptrtoint cast
5062 // doesn't truncate the pointers.
5063 if (Indices
[0]->getType()->getScalarSizeInBits() ==
5064 Q
.DL
.getPointerSizeInBits(AS
)) {
5065 auto CanSimplify
= [GEPTy
, &P
, Ptr
]() -> bool {
5066 return P
->getType() == GEPTy
&&
5067 getUnderlyingObject(P
) == getUnderlyingObject(Ptr
);
5069 // getelementptr V, (sub P, V) -> P if P points to a type of size 1.
5070 if (TyAllocSize
== 1 &&
5072 m_Sub(m_PtrToInt(m_Value(P
)), m_PtrToInt(m_Specific(Ptr
)))) &&
5076 // getelementptr V, (ashr (sub P, V), C) -> P if P points to a type of
5078 if (match(Indices
[0], m_AShr(m_Sub(m_PtrToInt(m_Value(P
)),
5079 m_PtrToInt(m_Specific(Ptr
))),
5080 m_ConstantInt(C
))) &&
5081 TyAllocSize
== 1ULL << C
&& CanSimplify())
5084 // getelementptr V, (sdiv (sub P, V), C) -> P if P points to a type of
5086 if (match(Indices
[0], m_SDiv(m_Sub(m_PtrToInt(m_Value(P
)),
5087 m_PtrToInt(m_Specific(Ptr
))),
5088 m_SpecificInt(TyAllocSize
))) &&
5095 if (!IsScalableVec
&& Q
.DL
.getTypeAllocSize(LastType
) == 1 &&
5096 all_of(Indices
.drop_back(1),
5097 [](Value
*Idx
) { return match(Idx
, m_Zero()); })) {
5099 Q
.DL
.getIndexSizeInBits(Ptr
->getType()->getPointerAddressSpace());
5100 if (Q
.DL
.getTypeSizeInBits(Indices
.back()->getType()) == IdxWidth
) {
5101 APInt
BasePtrOffset(IdxWidth
, 0);
5102 Value
*StrippedBasePtr
=
5103 Ptr
->stripAndAccumulateInBoundsConstantOffsets(Q
.DL
, BasePtrOffset
);
5105 // Avoid creating inttoptr of zero here: While LLVMs treatment of
5106 // inttoptr is generally conservative, this particular case is folded to
5107 // a null pointer, which will have incorrect provenance.
5109 // gep (gep V, C), (sub 0, V) -> C
5110 if (match(Indices
.back(),
5111 m_Neg(m_PtrToInt(m_Specific(StrippedBasePtr
)))) &&
5112 !BasePtrOffset
.isZero()) {
5113 auto *CI
= ConstantInt::get(GEPTy
->getContext(), BasePtrOffset
);
5114 return ConstantExpr::getIntToPtr(CI
, GEPTy
);
5116 // gep (gep V, C), (xor V, -1) -> C-1
5117 if (match(Indices
.back(),
5118 m_Xor(m_PtrToInt(m_Specific(StrippedBasePtr
)), m_AllOnes())) &&
5119 !BasePtrOffset
.isOne()) {
5120 auto *CI
= ConstantInt::get(GEPTy
->getContext(), BasePtrOffset
- 1);
5121 return ConstantExpr::getIntToPtr(CI
, GEPTy
);
5126 // Check to see if this is constant foldable.
5127 if (!isa
<Constant
>(Ptr
) ||
5128 !all_of(Indices
, [](Value
*V
) { return isa
<Constant
>(V
); }))
5131 if (!ConstantExpr::isSupportedGetElementPtr(SrcTy
))
5132 return ConstantFoldGetElementPtr(SrcTy
, cast
<Constant
>(Ptr
), std::nullopt
,
5136 ConstantExpr::getGetElementPtr(SrcTy
, cast
<Constant
>(Ptr
), Indices
, NW
);
5137 return ConstantFoldConstant(CE
, Q
.DL
);
5140 Value
*llvm::simplifyGEPInst(Type
*SrcTy
, Value
*Ptr
, ArrayRef
<Value
*> Indices
,
5141 GEPNoWrapFlags NW
, const SimplifyQuery
&Q
) {
5142 return ::simplifyGEPInst(SrcTy
, Ptr
, Indices
, NW
, Q
, RecursionLimit
);
5145 /// Given operands for an InsertValueInst, see if we can fold the result.
5146 /// If not, this returns null.
5147 static Value
*simplifyInsertValueInst(Value
*Agg
, Value
*Val
,
5148 ArrayRef
<unsigned> Idxs
,
5149 const SimplifyQuery
&Q
, unsigned) {
5150 if (Constant
*CAgg
= dyn_cast
<Constant
>(Agg
))
5151 if (Constant
*CVal
= dyn_cast
<Constant
>(Val
))
5152 return ConstantFoldInsertValueInstruction(CAgg
, CVal
, Idxs
);
5154 // insertvalue x, poison, n -> x
5155 // insertvalue x, undef, n -> x if x cannot be poison
5156 if (isa
<PoisonValue
>(Val
) ||
5157 (Q
.isUndefValue(Val
) && isGuaranteedNotToBePoison(Agg
)))
5160 // insertvalue x, (extractvalue y, n), n
5161 if (ExtractValueInst
*EV
= dyn_cast
<ExtractValueInst
>(Val
))
5162 if (EV
->getAggregateOperand()->getType() == Agg
->getType() &&
5163 EV
->getIndices() == Idxs
) {
5164 // insertvalue poison, (extractvalue y, n), n -> y
5165 // insertvalue undef, (extractvalue y, n), n -> y if y cannot be poison
5166 if (isa
<PoisonValue
>(Agg
) ||
5167 (Q
.isUndefValue(Agg
) &&
5168 isGuaranteedNotToBePoison(EV
->getAggregateOperand())))
5169 return EV
->getAggregateOperand();
5171 // insertvalue y, (extractvalue y, n), n -> y
5172 if (Agg
== EV
->getAggregateOperand())
5179 Value
*llvm::simplifyInsertValueInst(Value
*Agg
, Value
*Val
,
5180 ArrayRef
<unsigned> Idxs
,
5181 const SimplifyQuery
&Q
) {
5182 return ::simplifyInsertValueInst(Agg
, Val
, Idxs
, Q
, RecursionLimit
);
5185 Value
*llvm::simplifyInsertElementInst(Value
*Vec
, Value
*Val
, Value
*Idx
,
5186 const SimplifyQuery
&Q
) {
5187 // Try to constant fold.
5188 auto *VecC
= dyn_cast
<Constant
>(Vec
);
5189 auto *ValC
= dyn_cast
<Constant
>(Val
);
5190 auto *IdxC
= dyn_cast
<Constant
>(Idx
);
5191 if (VecC
&& ValC
&& IdxC
)
5192 return ConstantExpr::getInsertElement(VecC
, ValC
, IdxC
);
5194 // For fixed-length vector, fold into poison if index is out of bounds.
5195 if (auto *CI
= dyn_cast
<ConstantInt
>(Idx
)) {
5196 if (isa
<FixedVectorType
>(Vec
->getType()) &&
5197 CI
->uge(cast
<FixedVectorType
>(Vec
->getType())->getNumElements()))
5198 return PoisonValue::get(Vec
->getType());
5201 // If index is undef, it might be out of bounds (see above case)
5202 if (Q
.isUndefValue(Idx
))
5203 return PoisonValue::get(Vec
->getType());
5205 // If the scalar is poison, or it is undef and there is no risk of
5206 // propagating poison from the vector value, simplify to the vector value.
5207 if (isa
<PoisonValue
>(Val
) ||
5208 (Q
.isUndefValue(Val
) && isGuaranteedNotToBePoison(Vec
)))
5211 // Inserting the splatted value into a constant splat does nothing.
5212 if (VecC
&& ValC
&& VecC
->getSplatValue() == ValC
)
5215 // If we are extracting a value from a vector, then inserting it into the same
5216 // place, that's the input vector:
5217 // insertelt Vec, (extractelt Vec, Idx), Idx --> Vec
5218 if (match(Val
, m_ExtractElt(m_Specific(Vec
), m_Specific(Idx
))))
5224 /// Given operands for an ExtractValueInst, see if we can fold the result.
5225 /// If not, this returns null.
5226 static Value
*simplifyExtractValueInst(Value
*Agg
, ArrayRef
<unsigned> Idxs
,
5227 const SimplifyQuery
&, unsigned) {
5228 if (auto *CAgg
= dyn_cast
<Constant
>(Agg
))
5229 return ConstantFoldExtractValueInstruction(CAgg
, Idxs
);
5231 // extractvalue x, (insertvalue y, elt, n), n -> elt
5232 unsigned NumIdxs
= Idxs
.size();
5233 for (auto *IVI
= dyn_cast
<InsertValueInst
>(Agg
); IVI
!= nullptr;
5234 IVI
= dyn_cast
<InsertValueInst
>(IVI
->getAggregateOperand())) {
5235 ArrayRef
<unsigned> InsertValueIdxs
= IVI
->getIndices();
5236 unsigned NumInsertValueIdxs
= InsertValueIdxs
.size();
5237 unsigned NumCommonIdxs
= std::min(NumInsertValueIdxs
, NumIdxs
);
5238 if (InsertValueIdxs
.slice(0, NumCommonIdxs
) ==
5239 Idxs
.slice(0, NumCommonIdxs
)) {
5240 if (NumIdxs
== NumInsertValueIdxs
)
5241 return IVI
->getInsertedValueOperand();
5249 Value
*llvm::simplifyExtractValueInst(Value
*Agg
, ArrayRef
<unsigned> Idxs
,
5250 const SimplifyQuery
&Q
) {
5251 return ::simplifyExtractValueInst(Agg
, Idxs
, Q
, RecursionLimit
);
5254 /// Given operands for an ExtractElementInst, see if we can fold the result.
5255 /// If not, this returns null.
5256 static Value
*simplifyExtractElementInst(Value
*Vec
, Value
*Idx
,
5257 const SimplifyQuery
&Q
, unsigned) {
5258 auto *VecVTy
= cast
<VectorType
>(Vec
->getType());
5259 if (auto *CVec
= dyn_cast
<Constant
>(Vec
)) {
5260 if (auto *CIdx
= dyn_cast
<Constant
>(Idx
))
5261 return ConstantExpr::getExtractElement(CVec
, CIdx
);
5263 if (Q
.isUndefValue(Vec
))
5264 return UndefValue::get(VecVTy
->getElementType());
5267 // An undef extract index can be arbitrarily chosen to be an out-of-range
5268 // index value, which would result in the instruction being poison.
5269 if (Q
.isUndefValue(Idx
))
5270 return PoisonValue::get(VecVTy
->getElementType());
5272 // If extracting a specified index from the vector, see if we can recursively
5273 // find a previously computed scalar that was inserted into the vector.
5274 if (auto *IdxC
= dyn_cast
<ConstantInt
>(Idx
)) {
5275 // For fixed-length vector, fold into undef if index is out of bounds.
5276 unsigned MinNumElts
= VecVTy
->getElementCount().getKnownMinValue();
5277 if (isa
<FixedVectorType
>(VecVTy
) && IdxC
->getValue().uge(MinNumElts
))
5278 return PoisonValue::get(VecVTy
->getElementType());
5279 // Handle case where an element is extracted from a splat.
5280 if (IdxC
->getValue().ult(MinNumElts
))
5281 if (auto *Splat
= getSplatValue(Vec
))
5283 if (Value
*Elt
= findScalarElement(Vec
, IdxC
->getZExtValue()))
5286 // extractelt x, (insertelt y, elt, n), n -> elt
5287 // If the possibly-variable indices are trivially known to be equal
5288 // (because they are the same operand) then use the value that was
5289 // inserted directly.
5290 auto *IE
= dyn_cast
<InsertElementInst
>(Vec
);
5291 if (IE
&& IE
->getOperand(2) == Idx
)
5292 return IE
->getOperand(1);
5294 // The index is not relevant if our vector is a splat.
5295 if (Value
*Splat
= getSplatValue(Vec
))
5301 Value
*llvm::simplifyExtractElementInst(Value
*Vec
, Value
*Idx
,
5302 const SimplifyQuery
&Q
) {
5303 return ::simplifyExtractElementInst(Vec
, Idx
, Q
, RecursionLimit
);
5306 /// See if we can fold the given phi. If not, returns null.
5307 static Value
*simplifyPHINode(PHINode
*PN
, ArrayRef
<Value
*> IncomingValues
,
5308 const SimplifyQuery
&Q
) {
5309 // WARNING: no matter how worthwhile it may seem, we can not perform PHI CSE
5310 // here, because the PHI we may succeed simplifying to was not
5311 // def-reachable from the original PHI!
5313 // If all of the PHI's incoming values are the same then replace the PHI node
5314 // with the common value.
5315 Value
*CommonValue
= nullptr;
5316 bool HasPoisonInput
= false;
5317 bool HasUndefInput
= false;
5318 for (Value
*Incoming
: IncomingValues
) {
5319 // If the incoming value is the phi node itself, it can safely be skipped.
5322 if (isa
<PoisonValue
>(Incoming
)) {
5323 HasPoisonInput
= true;
5326 if (Q
.isUndefValue(Incoming
)) {
5327 // Remember that we saw an undef value, but otherwise ignore them.
5328 HasUndefInput
= true;
5331 if (CommonValue
&& Incoming
!= CommonValue
)
5332 return nullptr; // Not the same, bail out.
5333 CommonValue
= Incoming
;
5336 // If CommonValue is null then all of the incoming values were either undef,
5337 // poison or equal to the phi node itself.
5339 return HasUndefInput
? UndefValue::get(PN
->getType())
5340 : PoisonValue::get(PN
->getType());
5342 if (HasPoisonInput
|| HasUndefInput
) {
5343 // If we have a PHI node like phi(X, undef, X), where X is defined by some
5344 // instruction, we cannot return X as the result of the PHI node unless it
5345 // dominates the PHI block.
5346 if (!valueDominatesPHI(CommonValue
, PN
, Q
.DT
))
5349 // Make sure we do not replace an undef value with poison.
5350 if (HasUndefInput
&&
5351 !isGuaranteedNotToBePoison(CommonValue
, Q
.AC
, Q
.CxtI
, Q
.DT
))
5359 static Value
*simplifyCastInst(unsigned CastOpc
, Value
*Op
, Type
*Ty
,
5360 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
5361 if (auto *C
= dyn_cast
<Constant
>(Op
))
5362 return ConstantFoldCastOperand(CastOpc
, C
, Ty
, Q
.DL
);
5364 if (auto *CI
= dyn_cast
<CastInst
>(Op
)) {
5365 auto *Src
= CI
->getOperand(0);
5366 Type
*SrcTy
= Src
->getType();
5367 Type
*MidTy
= CI
->getType();
5369 if (Src
->getType() == Ty
) {
5370 auto FirstOp
= static_cast<Instruction::CastOps
>(CI
->getOpcode());
5371 auto SecondOp
= static_cast<Instruction::CastOps
>(CastOpc
);
5373 SrcTy
->isPtrOrPtrVectorTy() ? Q
.DL
.getIntPtrType(SrcTy
) : nullptr;
5375 MidTy
->isPtrOrPtrVectorTy() ? Q
.DL
.getIntPtrType(MidTy
) : nullptr;
5377 DstTy
->isPtrOrPtrVectorTy() ? Q
.DL
.getIntPtrType(DstTy
) : nullptr;
5378 if (CastInst::isEliminableCastPair(FirstOp
, SecondOp
, SrcTy
, MidTy
, DstTy
,
5379 SrcIntPtrTy
, MidIntPtrTy
,
5380 DstIntPtrTy
) == Instruction::BitCast
)
5386 if (CastOpc
== Instruction::BitCast
)
5387 if (Op
->getType() == Ty
)
5390 // ptrtoint (ptradd (Ptr, X - ptrtoint(Ptr))) -> X
5392 if (CastOpc
== Instruction::PtrToInt
&&
5393 match(Op
, m_PtrAdd(m_Value(Ptr
),
5394 m_Sub(m_Value(X
), m_PtrToInt(m_Deferred(Ptr
))))) &&
5395 X
->getType() == Ty
&& Ty
== Q
.DL
.getIndexType(Ptr
->getType()))
5401 Value
*llvm::simplifyCastInst(unsigned CastOpc
, Value
*Op
, Type
*Ty
,
5402 const SimplifyQuery
&Q
) {
5403 return ::simplifyCastInst(CastOpc
, Op
, Ty
, Q
, RecursionLimit
);
5406 /// For the given destination element of a shuffle, peek through shuffles to
5407 /// match a root vector source operand that contains that element in the same
5408 /// vector lane (ie, the same mask index), so we can eliminate the shuffle(s).
5409 static Value
*foldIdentityShuffles(int DestElt
, Value
*Op0
, Value
*Op1
,
5410 int MaskVal
, Value
*RootVec
,
5411 unsigned MaxRecurse
) {
5415 // Bail out if any mask value is undefined. That kind of shuffle may be
5416 // simplified further based on demanded bits or other folds.
5420 // The mask value chooses which source operand we need to look at next.
5421 int InVecNumElts
= cast
<FixedVectorType
>(Op0
->getType())->getNumElements();
5422 int RootElt
= MaskVal
;
5423 Value
*SourceOp
= Op0
;
5424 if (MaskVal
>= InVecNumElts
) {
5425 RootElt
= MaskVal
- InVecNumElts
;
5429 // If the source operand is a shuffle itself, look through it to find the
5430 // matching root vector.
5431 if (auto *SourceShuf
= dyn_cast
<ShuffleVectorInst
>(SourceOp
)) {
5432 return foldIdentityShuffles(
5433 DestElt
, SourceShuf
->getOperand(0), SourceShuf
->getOperand(1),
5434 SourceShuf
->getMaskValue(RootElt
), RootVec
, MaxRecurse
);
5437 // The source operand is not a shuffle. Initialize the root vector value for
5438 // this shuffle if that has not been done yet.
5442 // Give up as soon as a source operand does not match the existing root value.
5443 if (RootVec
!= SourceOp
)
5446 // The element must be coming from the same lane in the source vector
5447 // (although it may have crossed lanes in intermediate shuffles).
5448 if (RootElt
!= DestElt
)
5454 static Value
*simplifyShuffleVectorInst(Value
*Op0
, Value
*Op1
,
5455 ArrayRef
<int> Mask
, Type
*RetTy
,
5456 const SimplifyQuery
&Q
,
5457 unsigned MaxRecurse
) {
5458 if (all_of(Mask
, [](int Elem
) { return Elem
== PoisonMaskElem
; }))
5459 return PoisonValue::get(RetTy
);
5461 auto *InVecTy
= cast
<VectorType
>(Op0
->getType());
5462 unsigned MaskNumElts
= Mask
.size();
5463 ElementCount InVecEltCount
= InVecTy
->getElementCount();
5465 bool Scalable
= InVecEltCount
.isScalable();
5467 SmallVector
<int, 32> Indices
;
5468 Indices
.assign(Mask
.begin(), Mask
.end());
5470 // Canonicalization: If mask does not select elements from an input vector,
5471 // replace that input vector with poison.
5473 bool MaskSelects0
= false, MaskSelects1
= false;
5474 unsigned InVecNumElts
= InVecEltCount
.getKnownMinValue();
5475 for (unsigned i
= 0; i
!= MaskNumElts
; ++i
) {
5476 if (Indices
[i
] == -1)
5478 if ((unsigned)Indices
[i
] < InVecNumElts
)
5479 MaskSelects0
= true;
5481 MaskSelects1
= true;
5484 Op0
= PoisonValue::get(InVecTy
);
5486 Op1
= PoisonValue::get(InVecTy
);
5489 auto *Op0Const
= dyn_cast
<Constant
>(Op0
);
5490 auto *Op1Const
= dyn_cast
<Constant
>(Op1
);
5492 // If all operands are constant, constant fold the shuffle. This
5493 // transformation depends on the value of the mask which is not known at
5494 // compile time for scalable vectors
5495 if (Op0Const
&& Op1Const
)
5496 return ConstantExpr::getShuffleVector(Op0Const
, Op1Const
, Mask
);
5498 // Canonicalization: if only one input vector is constant, it shall be the
5499 // second one. This transformation depends on the value of the mask which
5500 // is not known at compile time for scalable vectors
5501 if (!Scalable
&& Op0Const
&& !Op1Const
) {
5502 std::swap(Op0
, Op1
);
5503 ShuffleVectorInst::commuteShuffleMask(Indices
,
5504 InVecEltCount
.getKnownMinValue());
5507 // A splat of an inserted scalar constant becomes a vector constant:
5508 // shuf (inselt ?, C, IndexC), undef, <IndexC, IndexC...> --> <C, C...>
5509 // NOTE: We may have commuted above, so analyze the updated Indices, not the
5510 // original mask constant.
5511 // NOTE: This transformation depends on the value of the mask which is not
5512 // known at compile time for scalable vectors
5514 ConstantInt
*IndexC
;
5515 if (!Scalable
&& match(Op0
, m_InsertElt(m_Value(), m_Constant(C
),
5516 m_ConstantInt(IndexC
)))) {
5517 // Match a splat shuffle mask of the insert index allowing undef elements.
5518 int InsertIndex
= IndexC
->getZExtValue();
5519 if (all_of(Indices
, [InsertIndex
](int MaskElt
) {
5520 return MaskElt
== InsertIndex
|| MaskElt
== -1;
5522 assert(isa
<UndefValue
>(Op1
) && "Expected undef operand 1 for splat");
5524 // Shuffle mask poisons become poison constant result elements.
5525 SmallVector
<Constant
*, 16> VecC(MaskNumElts
, C
);
5526 for (unsigned i
= 0; i
!= MaskNumElts
; ++i
)
5527 if (Indices
[i
] == -1)
5528 VecC
[i
] = PoisonValue::get(C
->getType());
5529 return ConstantVector::get(VecC
);
5533 // A shuffle of a splat is always the splat itself. Legal if the shuffle's
5534 // value type is same as the input vectors' type.
5535 if (auto *OpShuf
= dyn_cast
<ShuffleVectorInst
>(Op0
))
5536 if (Q
.isUndefValue(Op1
) && RetTy
== InVecTy
&&
5537 all_equal(OpShuf
->getShuffleMask()))
5540 // All remaining transformation depend on the value of the mask, which is
5541 // not known at compile time for scalable vectors.
5545 // Don't fold a shuffle with undef mask elements. This may get folded in a
5546 // better way using demanded bits or other analysis.
5547 // TODO: Should we allow this?
5548 if (is_contained(Indices
, -1))
5551 // Check if every element of this shuffle can be mapped back to the
5552 // corresponding element of a single root vector. If so, we don't need this
5553 // shuffle. This handles simple identity shuffles as well as chains of
5554 // shuffles that may widen/narrow and/or move elements across lanes and back.
5555 Value
*RootVec
= nullptr;
5556 for (unsigned i
= 0; i
!= MaskNumElts
; ++i
) {
5557 // Note that recursion is limited for each vector element, so if any element
5558 // exceeds the limit, this will fail to simplify.
5560 foldIdentityShuffles(i
, Op0
, Op1
, Indices
[i
], RootVec
, MaxRecurse
);
5562 // We can't replace a widening/narrowing shuffle with one of its operands.
5563 if (!RootVec
|| RootVec
->getType() != RetTy
)
5569 /// Given operands for a ShuffleVectorInst, fold the result or return null.
5570 Value
*llvm::simplifyShuffleVectorInst(Value
*Op0
, Value
*Op1
,
5571 ArrayRef
<int> Mask
, Type
*RetTy
,
5572 const SimplifyQuery
&Q
) {
5573 return ::simplifyShuffleVectorInst(Op0
, Op1
, Mask
, RetTy
, Q
, RecursionLimit
);
5576 static Constant
*foldConstant(Instruction::UnaryOps Opcode
, Value
*&Op
,
5577 const SimplifyQuery
&Q
) {
5578 if (auto *C
= dyn_cast
<Constant
>(Op
))
5579 return ConstantFoldUnaryOpOperand(Opcode
, C
, Q
.DL
);
5583 /// Given the operand for an FNeg, see if we can fold the result. If not, this
5585 static Value
*simplifyFNegInst(Value
*Op
, FastMathFlags FMF
,
5586 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
5587 if (Constant
*C
= foldConstant(Instruction::FNeg
, Op
, Q
))
5591 // fneg (fneg X) ==> X
5592 if (match(Op
, m_FNeg(m_Value(X
))))
5598 Value
*llvm::simplifyFNegInst(Value
*Op
, FastMathFlags FMF
,
5599 const SimplifyQuery
&Q
) {
5600 return ::simplifyFNegInst(Op
, FMF
, Q
, RecursionLimit
);
5603 /// Try to propagate existing NaN values when possible. If not, replace the
5604 /// constant or elements in the constant with a canonical NaN.
5605 static Constant
*propagateNaN(Constant
*In
) {
5606 Type
*Ty
= In
->getType();
5607 if (auto *VecTy
= dyn_cast
<FixedVectorType
>(Ty
)) {
5608 unsigned NumElts
= VecTy
->getNumElements();
5609 SmallVector
<Constant
*, 32> NewC(NumElts
);
5610 for (unsigned i
= 0; i
!= NumElts
; ++i
) {
5611 Constant
*EltC
= In
->getAggregateElement(i
);
5612 // Poison elements propagate. NaN propagates except signaling is quieted.
5613 // Replace unknown or undef elements with canonical NaN.
5614 if (EltC
&& isa
<PoisonValue
>(EltC
))
5616 else if (EltC
&& EltC
->isNaN())
5617 NewC
[i
] = ConstantFP::get(
5618 EltC
->getType(), cast
<ConstantFP
>(EltC
)->getValue().makeQuiet());
5620 NewC
[i
] = ConstantFP::getNaN(VecTy
->getElementType());
5622 return ConstantVector::get(NewC
);
5625 // If it is not a fixed vector, but not a simple NaN either, return a
5628 return ConstantFP::getNaN(Ty
);
5630 // If we known this is a NaN, and it's scalable vector, we must have a splat
5631 // on our hands. Grab that before splatting a QNaN constant.
5632 if (isa
<ScalableVectorType
>(Ty
)) {
5633 auto *Splat
= In
->getSplatValue();
5634 assert(Splat
&& Splat
->isNaN() &&
5635 "Found a scalable-vector NaN but not a splat");
5639 // Propagate an existing QNaN constant. If it is an SNaN, make it quiet, but
5640 // preserve the sign/payload.
5641 return ConstantFP::get(Ty
, cast
<ConstantFP
>(In
)->getValue().makeQuiet());
5644 /// Perform folds that are common to any floating-point operation. This implies
5645 /// transforms based on poison/undef/NaN because the operation itself makes no
5646 /// difference to the result.
5647 static Constant
*simplifyFPOp(ArrayRef
<Value
*> Ops
, FastMathFlags FMF
,
5648 const SimplifyQuery
&Q
,
5649 fp::ExceptionBehavior ExBehavior
,
5650 RoundingMode Rounding
) {
5651 // Poison is independent of anything else. It always propagates from an
5652 // operand to a math result.
5653 if (any_of(Ops
, [](Value
*V
) { return match(V
, m_Poison()); }))
5654 return PoisonValue::get(Ops
[0]->getType());
5656 for (Value
*V
: Ops
) {
5657 bool IsNan
= match(V
, m_NaN());
5658 bool IsInf
= match(V
, m_Inf());
5659 bool IsUndef
= Q
.isUndefValue(V
);
5661 // If this operation has 'nnan' or 'ninf' and at least 1 disallowed operand
5662 // (an undef operand can be chosen to be Nan/Inf), then the result of
5663 // this operation is poison.
5664 if (FMF
.noNaNs() && (IsNan
|| IsUndef
))
5665 return PoisonValue::get(V
->getType());
5666 if (FMF
.noInfs() && (IsInf
|| IsUndef
))
5667 return PoisonValue::get(V
->getType());
5669 if (isDefaultFPEnvironment(ExBehavior
, Rounding
)) {
5670 // Undef does not propagate because undef means that all bits can take on
5671 // any value. If this is undef * NaN for example, then the result values
5672 // (at least the exponent bits) are limited. Assume the undef is a
5673 // canonical NaN and propagate that.
5675 return ConstantFP::getNaN(V
->getType());
5677 return propagateNaN(cast
<Constant
>(V
));
5678 } else if (ExBehavior
!= fp::ebStrict
) {
5680 return propagateNaN(cast
<Constant
>(V
));
5686 /// Given operands for an FAdd, see if we can fold the result. If not, this
5689 simplifyFAddInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5690 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5691 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5692 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5693 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5694 if (Constant
*C
= foldOrCommuteConstant(Instruction::FAdd
, Op0
, Op1
, Q
))
5697 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5701 // With strict/constrained FP, we have these possible edge cases that do
5702 // not simplify to Op0:
5703 // fadd SNaN, -0.0 --> QNaN
5704 // fadd +0.0, -0.0 --> -0.0 (but only with round toward negative)
5705 if (canIgnoreSNaN(ExBehavior
, FMF
) &&
5706 (!canRoundingModeBe(Rounding
, RoundingMode::TowardNegative
) ||
5707 FMF
.noSignedZeros()))
5708 if (match(Op1
, m_NegZeroFP()))
5711 // fadd X, 0 ==> X, when we know X is not -0
5712 if (canIgnoreSNaN(ExBehavior
, FMF
))
5713 if (match(Op1
, m_PosZeroFP()) &&
5714 (FMF
.noSignedZeros() || cannotBeNegativeZero(Op0
, /*Depth=*/0, Q
)))
5717 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5721 // With nnan: X + {+/-}Inf --> {+/-}Inf
5722 if (match(Op1
, m_Inf()))
5725 // With nnan: -X + X --> 0.0 (and commuted variant)
5726 // We don't have to explicitly exclude infinities (ninf): INF + -INF == NaN.
5727 // Negative zeros are allowed because we always end up with positive zero:
5728 // X = -0.0: (-0.0 - (-0.0)) + (-0.0) == ( 0.0) + (-0.0) == 0.0
5729 // X = -0.0: ( 0.0 - (-0.0)) + (-0.0) == ( 0.0) + (-0.0) == 0.0
5730 // X = 0.0: (-0.0 - ( 0.0)) + ( 0.0) == (-0.0) + ( 0.0) == 0.0
5731 // X = 0.0: ( 0.0 - ( 0.0)) + ( 0.0) == ( 0.0) + ( 0.0) == 0.0
5732 if (match(Op0
, m_FSub(m_AnyZeroFP(), m_Specific(Op1
))) ||
5733 match(Op1
, m_FSub(m_AnyZeroFP(), m_Specific(Op0
))))
5734 return ConstantFP::getZero(Op0
->getType());
5736 if (match(Op0
, m_FNeg(m_Specific(Op1
))) ||
5737 match(Op1
, m_FNeg(m_Specific(Op0
))))
5738 return ConstantFP::getZero(Op0
->getType());
5741 // (X - Y) + Y --> X
5742 // Y + (X - Y) --> X
5744 if (FMF
.noSignedZeros() && FMF
.allowReassoc() &&
5745 (match(Op0
, m_FSub(m_Value(X
), m_Specific(Op1
))) ||
5746 match(Op1
, m_FSub(m_Value(X
), m_Specific(Op0
)))))
5752 /// Given operands for an FSub, see if we can fold the result. If not, this
5755 simplifyFSubInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5756 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5757 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5758 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5759 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5760 if (Constant
*C
= foldOrCommuteConstant(Instruction::FSub
, Op0
, Op1
, Q
))
5763 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5767 if (canIgnoreSNaN(ExBehavior
, FMF
) &&
5768 (!canRoundingModeBe(Rounding
, RoundingMode::TowardNegative
) ||
5769 FMF
.noSignedZeros()))
5770 if (match(Op1
, m_PosZeroFP()))
5773 // fsub X, -0 ==> X, when we know X is not -0
5774 if (canIgnoreSNaN(ExBehavior
, FMF
))
5775 if (match(Op1
, m_NegZeroFP()) &&
5776 (FMF
.noSignedZeros() || cannotBeNegativeZero(Op0
, /*Depth=*/0, Q
)))
5779 // fsub -0.0, (fsub -0.0, X) ==> X
5780 // fsub -0.0, (fneg X) ==> X
5782 if (canIgnoreSNaN(ExBehavior
, FMF
))
5783 if (match(Op0
, m_NegZeroFP()) && match(Op1
, m_FNeg(m_Value(X
))))
5786 // fsub 0.0, (fsub 0.0, X) ==> X if signed zeros are ignored.
5787 // fsub 0.0, (fneg X) ==> X if signed zeros are ignored.
5788 if (canIgnoreSNaN(ExBehavior
, FMF
))
5789 if (FMF
.noSignedZeros() && match(Op0
, m_AnyZeroFP()) &&
5790 (match(Op1
, m_FSub(m_AnyZeroFP(), m_Value(X
))) ||
5791 match(Op1
, m_FNeg(m_Value(X
)))))
5794 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5798 // fsub nnan x, x ==> 0.0
5800 return Constant::getNullValue(Op0
->getType());
5802 // With nnan: {+/-}Inf - X --> {+/-}Inf
5803 if (match(Op0
, m_Inf()))
5806 // With nnan: X - {+/-}Inf --> {-/+}Inf
5807 if (match(Op1
, m_Inf()))
5808 return foldConstant(Instruction::FNeg
, Op1
, Q
);
5811 // Y - (Y - X) --> X
5812 // (X + Y) - Y --> X
5813 if (FMF
.noSignedZeros() && FMF
.allowReassoc() &&
5814 (match(Op1
, m_FSub(m_Specific(Op0
), m_Value(X
))) ||
5815 match(Op0
, m_c_FAdd(m_Specific(Op1
), m_Value(X
)))))
5821 static Value
*simplifyFMAFMul(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5822 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5823 fp::ExceptionBehavior ExBehavior
,
5824 RoundingMode Rounding
) {
5825 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5828 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5831 // Canonicalize special constants as operand 1.
5832 if (match(Op0
, m_FPOne()) || match(Op0
, m_AnyZeroFP()))
5833 std::swap(Op0
, Op1
);
5836 if (match(Op1
, m_FPOne()))
5839 if (match(Op1
, m_AnyZeroFP())) {
5840 // X * 0.0 --> 0.0 (with nnan and nsz)
5841 if (FMF
.noNaNs() && FMF
.noSignedZeros())
5842 return ConstantFP::getZero(Op0
->getType());
5844 KnownFPClass Known
=
5845 computeKnownFPClass(Op0
, FMF
, fcInf
| fcNan
, /*Depth=*/0, Q
);
5846 if (Known
.isKnownNever(fcInf
| fcNan
)) {
5847 // +normal number * (-)0.0 --> (-)0.0
5848 if (Known
.SignBit
== false)
5850 // -normal number * (-)0.0 --> -(-)0.0
5851 if (Known
.SignBit
== true)
5852 return foldConstant(Instruction::FNeg
, Op1
, Q
);
5856 // sqrt(X) * sqrt(X) --> X, if we can:
5857 // 1. Remove the intermediate rounding (reassociate).
5858 // 2. Ignore non-zero negative numbers because sqrt would produce NAN.
5859 // 3. Ignore -0.0 because sqrt(-0.0) == -0.0, but -0.0 * -0.0 == 0.0.
5861 if (Op0
== Op1
&& match(Op0
, m_Sqrt(m_Value(X
))) && FMF
.allowReassoc() &&
5862 FMF
.noNaNs() && FMF
.noSignedZeros())
5868 /// Given the operands for an FMul, see if we can fold the result
5870 simplifyFMulInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5871 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5872 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5873 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5874 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5875 if (Constant
*C
= foldOrCommuteConstant(Instruction::FMul
, Op0
, Op1
, Q
))
5878 // Now apply simplifications that do not require rounding.
5879 return simplifyFMAFMul(Op0
, Op1
, FMF
, Q
, MaxRecurse
, ExBehavior
, Rounding
);
5882 Value
*llvm::simplifyFAddInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5883 const SimplifyQuery
&Q
,
5884 fp::ExceptionBehavior ExBehavior
,
5885 RoundingMode Rounding
) {
5886 return ::simplifyFAddInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5890 Value
*llvm::simplifyFSubInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5891 const SimplifyQuery
&Q
,
5892 fp::ExceptionBehavior ExBehavior
,
5893 RoundingMode Rounding
) {
5894 return ::simplifyFSubInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5898 Value
*llvm::simplifyFMulInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5899 const SimplifyQuery
&Q
,
5900 fp::ExceptionBehavior ExBehavior
,
5901 RoundingMode Rounding
) {
5902 return ::simplifyFMulInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5906 Value
*llvm::simplifyFMAFMul(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5907 const SimplifyQuery
&Q
,
5908 fp::ExceptionBehavior ExBehavior
,
5909 RoundingMode Rounding
) {
5910 return ::simplifyFMAFMul(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5915 simplifyFDivInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5916 const SimplifyQuery
&Q
, unsigned,
5917 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5918 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5919 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5920 if (Constant
*C
= foldOrCommuteConstant(Instruction::FDiv
, Op0
, Op1
, Q
))
5923 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5926 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5930 if (match(Op1
, m_FPOne()))
5934 // Requires that NaNs are off (X could be zero) and signed zeroes are
5935 // ignored (X could be positive or negative, so the output sign is unknown).
5936 if (FMF
.noNaNs() && FMF
.noSignedZeros() && match(Op0
, m_AnyZeroFP()))
5937 return ConstantFP::getZero(Op0
->getType());
5940 // X / X -> 1.0 is legal when NaNs are ignored.
5941 // We can ignore infinities because INF/INF is NaN.
5943 return ConstantFP::get(Op0
->getType(), 1.0);
5945 // (X * Y) / Y --> X if we can reassociate to the above form.
5947 if (FMF
.allowReassoc() && match(Op0
, m_c_FMul(m_Value(X
), m_Specific(Op1
))))
5950 // -X / X -> -1.0 and
5951 // X / -X -> -1.0 are legal when NaNs are ignored.
5952 // We can ignore signed zeros because +-0.0/+-0.0 is NaN and ignored.
5953 if (match(Op0
, m_FNegNSZ(m_Specific(Op1
))) ||
5954 match(Op1
, m_FNegNSZ(m_Specific(Op0
))))
5955 return ConstantFP::get(Op0
->getType(), -1.0);
5957 // nnan ninf X / [-]0.0 -> poison
5958 if (FMF
.noInfs() && match(Op1
, m_AnyZeroFP()))
5959 return PoisonValue::get(Op1
->getType());
5965 Value
*llvm::simplifyFDivInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5966 const SimplifyQuery
&Q
,
5967 fp::ExceptionBehavior ExBehavior
,
5968 RoundingMode Rounding
) {
5969 return ::simplifyFDivInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5974 simplifyFRemInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5975 const SimplifyQuery
&Q
, unsigned,
5976 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5977 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5978 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5979 if (Constant
*C
= foldOrCommuteConstant(Instruction::FRem
, Op0
, Op1
, Q
))
5982 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5985 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5988 // Unlike fdiv, the result of frem always matches the sign of the dividend.
5989 // The constant match may include undef elements in a vector, so return a full
5990 // zero constant as the result.
5993 if (match(Op0
, m_PosZeroFP()))
5994 return ConstantFP::getZero(Op0
->getType());
5996 if (match(Op0
, m_NegZeroFP()))
5997 return ConstantFP::getNegativeZero(Op0
->getType());
6003 Value
*llvm::simplifyFRemInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
6004 const SimplifyQuery
&Q
,
6005 fp::ExceptionBehavior ExBehavior
,
6006 RoundingMode Rounding
) {
6007 return ::simplifyFRemInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
6011 //=== Helper functions for higher up the class hierarchy.
6013 /// Given the operand for a UnaryOperator, see if we can fold the result.
6014 /// If not, this returns null.
6015 static Value
*simplifyUnOp(unsigned Opcode
, Value
*Op
, const SimplifyQuery
&Q
,
6016 unsigned MaxRecurse
) {
6018 case Instruction::FNeg
:
6019 return simplifyFNegInst(Op
, FastMathFlags(), Q
, MaxRecurse
);
6021 llvm_unreachable("Unexpected opcode");
6025 /// Given the operand for a UnaryOperator, see if we can fold the result.
6026 /// If not, this returns null.
6027 /// Try to use FastMathFlags when folding the result.
6028 static Value
*simplifyFPUnOp(unsigned Opcode
, Value
*Op
,
6029 const FastMathFlags
&FMF
, const SimplifyQuery
&Q
,
6030 unsigned MaxRecurse
) {
6032 case Instruction::FNeg
:
6033 return simplifyFNegInst(Op
, FMF
, Q
, MaxRecurse
);
6035 return simplifyUnOp(Opcode
, Op
, Q
, MaxRecurse
);
6039 Value
*llvm::simplifyUnOp(unsigned Opcode
, Value
*Op
, const SimplifyQuery
&Q
) {
6040 return ::simplifyUnOp(Opcode
, Op
, Q
, RecursionLimit
);
6043 Value
*llvm::simplifyUnOp(unsigned Opcode
, Value
*Op
, FastMathFlags FMF
,
6044 const SimplifyQuery
&Q
) {
6045 return ::simplifyFPUnOp(Opcode
, Op
, FMF
, Q
, RecursionLimit
);
6048 /// Given operands for a BinaryOperator, see if we can fold the result.
6049 /// If not, this returns null.
6050 static Value
*simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
6051 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
6053 case Instruction::Add
:
6054 return simplifyAddInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
6056 case Instruction::Sub
:
6057 return simplifySubInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
6059 case Instruction::Mul
:
6060 return simplifyMulInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
6062 case Instruction::SDiv
:
6063 return simplifySDivInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
6064 case Instruction::UDiv
:
6065 return simplifyUDivInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
6066 case Instruction::SRem
:
6067 return simplifySRemInst(LHS
, RHS
, Q
, MaxRecurse
);
6068 case Instruction::URem
:
6069 return simplifyURemInst(LHS
, RHS
, Q
, MaxRecurse
);
6070 case Instruction::Shl
:
6071 return simplifyShlInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
6073 case Instruction::LShr
:
6074 return simplifyLShrInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
6075 case Instruction::AShr
:
6076 return simplifyAShrInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
6077 case Instruction::And
:
6078 return simplifyAndInst(LHS
, RHS
, Q
, MaxRecurse
);
6079 case Instruction::Or
:
6080 return simplifyOrInst(LHS
, RHS
, Q
, MaxRecurse
);
6081 case Instruction::Xor
:
6082 return simplifyXorInst(LHS
, RHS
, Q
, MaxRecurse
);
6083 case Instruction::FAdd
:
6084 return simplifyFAddInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6085 case Instruction::FSub
:
6086 return simplifyFSubInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6087 case Instruction::FMul
:
6088 return simplifyFMulInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6089 case Instruction::FDiv
:
6090 return simplifyFDivInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6091 case Instruction::FRem
:
6092 return simplifyFRemInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6094 llvm_unreachable("Unexpected opcode");
6098 /// Given operands for a BinaryOperator, see if we can fold the result.
6099 /// If not, this returns null.
6100 /// Try to use FastMathFlags when folding the result.
6101 static Value
*simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
6102 const FastMathFlags
&FMF
, const SimplifyQuery
&Q
,
6103 unsigned MaxRecurse
) {
6105 case Instruction::FAdd
:
6106 return simplifyFAddInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6107 case Instruction::FSub
:
6108 return simplifyFSubInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6109 case Instruction::FMul
:
6110 return simplifyFMulInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6111 case Instruction::FDiv
:
6112 return simplifyFDivInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6114 return simplifyBinOp(Opcode
, LHS
, RHS
, Q
, MaxRecurse
);
6118 Value
*llvm::simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
6119 const SimplifyQuery
&Q
) {
6120 return ::simplifyBinOp(Opcode
, LHS
, RHS
, Q
, RecursionLimit
);
6123 Value
*llvm::simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
6124 FastMathFlags FMF
, const SimplifyQuery
&Q
) {
6125 return ::simplifyBinOp(Opcode
, LHS
, RHS
, FMF
, Q
, RecursionLimit
);
6128 /// Given operands for a CmpInst, see if we can fold the result.
6129 static Value
*simplifyCmpInst(CmpPredicate Predicate
, Value
*LHS
, Value
*RHS
,
6130 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
6131 if (CmpInst::isIntPredicate(Predicate
))
6132 return simplifyICmpInst(Predicate
, LHS
, RHS
, Q
, MaxRecurse
);
6133 return simplifyFCmpInst(Predicate
, LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6136 Value
*llvm::simplifyCmpInst(CmpPredicate Predicate
, Value
*LHS
, Value
*RHS
,
6137 const SimplifyQuery
&Q
) {
6138 return ::simplifyCmpInst(Predicate
, LHS
, RHS
, Q
, RecursionLimit
);
6141 static bool isIdempotent(Intrinsic::ID ID
) {
6146 // Unary idempotent: f(f(x)) = f(x)
6147 case Intrinsic::fabs
:
6148 case Intrinsic::floor
:
6149 case Intrinsic::ceil
:
6150 case Intrinsic::trunc
:
6151 case Intrinsic::rint
:
6152 case Intrinsic::nearbyint
:
6153 case Intrinsic::round
:
6154 case Intrinsic::roundeven
:
6155 case Intrinsic::canonicalize
:
6156 case Intrinsic::arithmetic_fence
:
6161 /// Return true if the intrinsic rounds a floating-point value to an integral
6162 /// floating-point value (not an integer type).
6163 static bool removesFPFraction(Intrinsic::ID ID
) {
6168 case Intrinsic::floor
:
6169 case Intrinsic::ceil
:
6170 case Intrinsic::trunc
:
6171 case Intrinsic::rint
:
6172 case Intrinsic::nearbyint
:
6173 case Intrinsic::round
:
6174 case Intrinsic::roundeven
:
6179 static Value
*simplifyRelativeLoad(Constant
*Ptr
, Constant
*Offset
,
6180 const DataLayout
&DL
) {
6181 GlobalValue
*PtrSym
;
6183 if (!IsConstantOffsetFromGlobal(Ptr
, PtrSym
, PtrOffset
, DL
))
6186 Type
*Int32Ty
= Type::getInt32Ty(Ptr
->getContext());
6188 auto *OffsetConstInt
= dyn_cast
<ConstantInt
>(Offset
);
6189 if (!OffsetConstInt
|| OffsetConstInt
->getBitWidth() > 64)
6192 APInt OffsetInt
= OffsetConstInt
->getValue().sextOrTrunc(
6193 DL
.getIndexTypeSizeInBits(Ptr
->getType()));
6194 if (OffsetInt
.srem(4) != 0)
6198 ConstantFoldLoadFromConstPtr(Ptr
, Int32Ty
, std::move(OffsetInt
), DL
);
6202 auto *LoadedCE
= dyn_cast
<ConstantExpr
>(Loaded
);
6206 if (LoadedCE
->getOpcode() == Instruction::Trunc
) {
6207 LoadedCE
= dyn_cast
<ConstantExpr
>(LoadedCE
->getOperand(0));
6212 if (LoadedCE
->getOpcode() != Instruction::Sub
)
6215 auto *LoadedLHS
= dyn_cast
<ConstantExpr
>(LoadedCE
->getOperand(0));
6216 if (!LoadedLHS
|| LoadedLHS
->getOpcode() != Instruction::PtrToInt
)
6218 auto *LoadedLHSPtr
= LoadedLHS
->getOperand(0);
6220 Constant
*LoadedRHS
= LoadedCE
->getOperand(1);
6221 GlobalValue
*LoadedRHSSym
;
6222 APInt LoadedRHSOffset
;
6223 if (!IsConstantOffsetFromGlobal(LoadedRHS
, LoadedRHSSym
, LoadedRHSOffset
,
6225 PtrSym
!= LoadedRHSSym
|| PtrOffset
!= LoadedRHSOffset
)
6228 return LoadedLHSPtr
;
6231 // TODO: Need to pass in FastMathFlags
6232 static Value
*simplifyLdexp(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
6234 // ldexp(poison, x) -> poison
6235 // ldexp(x, poison) -> poison
6236 if (isa
<PoisonValue
>(Op0
) || isa
<PoisonValue
>(Op1
))
6239 // ldexp(undef, x) -> nan
6240 if (Q
.isUndefValue(Op0
))
6241 return ConstantFP::getNaN(Op0
->getType());
6244 // TODO: Could insert a canonicalize for strict
6246 // ldexp(x, undef) -> x
6247 if (Q
.isUndefValue(Op1
))
6251 const APFloat
*C
= nullptr;
6252 match(Op0
, PatternMatch::m_APFloat(C
));
6254 // These cases should be safe, even with strictfp.
6255 // ldexp(0.0, x) -> 0.0
6256 // ldexp(-0.0, x) -> -0.0
6257 // ldexp(inf, x) -> inf
6258 // ldexp(-inf, x) -> -inf
6259 if (C
&& (C
->isZero() || C
->isInfinity()))
6262 // These are canonicalization dropping, could do it if we knew how we could
6263 // ignore denormal flushes and target handling of nan payload bits.
6267 // TODO: Could quiet this with strictfp if the exception mode isn't strict.
6268 if (C
&& C
->isNaN())
6269 return ConstantFP::get(Op0
->getType(), C
->makeQuiet());
6273 // TODO: Could fold this if we know the exception mode isn't
6274 // strict, we know the denormal mode and other target modes.
6275 if (match(Op1
, PatternMatch::m_ZeroInt()))
6281 static Value
*simplifyUnaryIntrinsic(Function
*F
, Value
*Op0
,
6282 const SimplifyQuery
&Q
,
6283 const CallBase
*Call
) {
6284 // Idempotent functions return the same result when called repeatedly.
6285 Intrinsic::ID IID
= F
->getIntrinsicID();
6286 if (isIdempotent(IID
))
6287 if (auto *II
= dyn_cast
<IntrinsicInst
>(Op0
))
6288 if (II
->getIntrinsicID() == IID
)
6291 if (removesFPFraction(IID
)) {
6292 // Converting from int or calling a rounding function always results in a
6293 // finite integral number or infinity. For those inputs, rounding functions
6294 // always return the same value, so the (2nd) rounding is eliminated. Ex:
6295 // floor (sitofp x) -> sitofp x
6296 // round (ceil x) -> ceil x
6297 auto *II
= dyn_cast
<IntrinsicInst
>(Op0
);
6298 if ((II
&& removesFPFraction(II
->getIntrinsicID())) ||
6299 match(Op0
, m_SIToFP(m_Value())) || match(Op0
, m_UIToFP(m_Value())))
6305 case Intrinsic::fabs
:
6306 if (computeKnownFPSignBit(Op0
, /*Depth=*/0, Q
) == false)
6309 case Intrinsic::bswap
:
6310 // bswap(bswap(x)) -> x
6311 if (match(Op0
, m_BSwap(m_Value(X
))))
6314 case Intrinsic::bitreverse
:
6315 // bitreverse(bitreverse(x)) -> x
6316 if (match(Op0
, m_BitReverse(m_Value(X
))))
6319 case Intrinsic::ctpop
: {
6320 // ctpop(X) -> 1 iff X is non-zero power of 2.
6321 if (isKnownToBeAPowerOfTwo(Op0
, Q
.DL
, /*OrZero*/ false, 0, Q
.AC
, Q
.CxtI
,
6323 return ConstantInt::get(Op0
->getType(), 1);
6324 // If everything but the lowest bit is zero, that bit is the pop-count. Ex:
6325 // ctpop(and X, 1) --> and X, 1
6326 unsigned BitWidth
= Op0
->getType()->getScalarSizeInBits();
6327 if (MaskedValueIsZero(Op0
, APInt::getHighBitsSet(BitWidth
, BitWidth
- 1),
6332 case Intrinsic::exp
:
6334 if (Call
->hasAllowReassoc() &&
6335 match(Op0
, m_Intrinsic
<Intrinsic::log
>(m_Value(X
))))
6338 case Intrinsic::exp2
:
6339 // exp2(log2(x)) -> x
6340 if (Call
->hasAllowReassoc() &&
6341 match(Op0
, m_Intrinsic
<Intrinsic::log2
>(m_Value(X
))))
6344 case Intrinsic::exp10
:
6345 // exp10(log10(x)) -> x
6346 if (Call
->hasAllowReassoc() &&
6347 match(Op0
, m_Intrinsic
<Intrinsic::log10
>(m_Value(X
))))
6350 case Intrinsic::log
:
6352 if (Call
->hasAllowReassoc() &&
6353 match(Op0
, m_Intrinsic
<Intrinsic::exp
>(m_Value(X
))))
6356 case Intrinsic::log2
:
6357 // log2(exp2(x)) -> x
6358 if (Call
->hasAllowReassoc() &&
6359 (match(Op0
, m_Intrinsic
<Intrinsic::exp2
>(m_Value(X
))) ||
6361 m_Intrinsic
<Intrinsic::pow
>(m_SpecificFP(2.0), m_Value(X
)))))
6364 case Intrinsic::log10
:
6365 // log10(pow(10.0, x)) -> x
6366 // log10(exp10(x)) -> x
6367 if (Call
->hasAllowReassoc() &&
6368 (match(Op0
, m_Intrinsic
<Intrinsic::exp10
>(m_Value(X
))) ||
6370 m_Intrinsic
<Intrinsic::pow
>(m_SpecificFP(10.0), m_Value(X
)))))
6373 case Intrinsic::vector_reverse
:
6374 // vector.reverse(vector.reverse(x)) -> x
6375 if (match(Op0
, m_VecReverse(m_Value(X
))))
6377 // vector.reverse(splat(X)) -> splat(X)
6378 if (isSplatValue(Op0
))
6381 case Intrinsic::frexp
: {
6382 // Frexp is idempotent with the added complication of the struct return.
6383 if (match(Op0
, m_ExtractValue
<0>(m_Value(X
)))) {
6384 if (match(X
, m_Intrinsic
<Intrinsic::frexp
>(m_Value())))
6397 /// Given a min/max intrinsic, see if it can be removed based on having an
6398 /// operand that is another min/max intrinsic with shared operand(s). The caller
6399 /// is expected to swap the operand arguments to handle commutation.
6400 static Value
*foldMinMaxSharedOp(Intrinsic::ID IID
, Value
*Op0
, Value
*Op1
) {
6402 if (!match(Op0
, m_MaxOrMin(m_Value(X
), m_Value(Y
))))
6405 auto *MM0
= dyn_cast
<IntrinsicInst
>(Op0
);
6408 Intrinsic::ID IID0
= MM0
->getIntrinsicID();
6410 if (Op1
== X
|| Op1
== Y
||
6411 match(Op1
, m_c_MaxOrMin(m_Specific(X
), m_Specific(Y
)))) {
6412 // max (max X, Y), X --> max X, Y
6415 // max (min X, Y), X --> X
6416 if (IID0
== getInverseMinMaxIntrinsic(IID
))
6422 /// Given a min/max intrinsic, see if it can be removed based on having an
6423 /// operand that is another min/max intrinsic with shared operand(s). The caller
6424 /// is expected to swap the operand arguments to handle commutation.
6425 static Value
*foldMinimumMaximumSharedOp(Intrinsic::ID IID
, Value
*Op0
,
6427 assert((IID
== Intrinsic::maxnum
|| IID
== Intrinsic::minnum
||
6428 IID
== Intrinsic::maximum
|| IID
== Intrinsic::minimum
) &&
6429 "Unsupported intrinsic");
6431 auto *M0
= dyn_cast
<IntrinsicInst
>(Op0
);
6432 // If Op0 is not the same intrinsic as IID, do not process.
6433 // This is a difference with integer min/max handling. We do not process the
6434 // case like max(min(X,Y),min(X,Y)) => min(X,Y). But it can be handled by GVN.
6435 if (!M0
|| M0
->getIntrinsicID() != IID
)
6437 Value
*X0
= M0
->getOperand(0);
6438 Value
*Y0
= M0
->getOperand(1);
6439 // Simple case, m(m(X,Y), X) => m(X, Y)
6440 // m(m(X,Y), Y) => m(X, Y)
6441 // For minimum/maximum, X is NaN => m(NaN, Y) == NaN and m(NaN, NaN) == NaN.
6442 // For minimum/maximum, Y is NaN => m(X, NaN) == NaN and m(NaN, NaN) == NaN.
6443 // For minnum/maxnum, X is NaN => m(NaN, Y) == Y and m(Y, Y) == Y.
6444 // For minnum/maxnum, Y is NaN => m(X, NaN) == X and m(X, NaN) == X.
6445 if (X0
== Op1
|| Y0
== Op1
)
6448 auto *M1
= dyn_cast
<IntrinsicInst
>(Op1
);
6451 Value
*X1
= M1
->getOperand(0);
6452 Value
*Y1
= M1
->getOperand(1);
6453 Intrinsic::ID IID1
= M1
->getIntrinsicID();
6454 // we have a case m(m(X,Y),m'(X,Y)) taking into account m' is commutative.
6455 // if m' is m or inversion of m => m(m(X,Y),m'(X,Y)) == m(X,Y).
6456 // For minimum/maximum, X is NaN => m(NaN,Y) == m'(NaN, Y) == NaN.
6457 // For minimum/maximum, Y is NaN => m(X,NaN) == m'(X, NaN) == NaN.
6458 // For minnum/maxnum, X is NaN => m(NaN,Y) == m'(NaN, Y) == Y.
6459 // For minnum/maxnum, Y is NaN => m(X,NaN) == m'(X, NaN) == X.
6460 if ((X0
== X1
&& Y0
== Y1
) || (X0
== Y1
&& Y0
== X1
))
6461 if (IID1
== IID
|| getInverseMinMaxIntrinsic(IID1
) == IID
)
6467 Value
*llvm::simplifyBinaryIntrinsic(Intrinsic::ID IID
, Type
*ReturnType
,
6468 Value
*Op0
, Value
*Op1
,
6469 const SimplifyQuery
&Q
,
6470 const CallBase
*Call
) {
6471 unsigned BitWidth
= ReturnType
->getScalarSizeInBits();
6473 case Intrinsic::abs
:
6474 // abs(abs(x)) -> abs(x). We don't need to worry about the nsw arg here.
6475 // It is always ok to pick the earlier abs. We'll just lose nsw if its only
6476 // on the outer abs.
6477 if (match(Op0
, m_Intrinsic
<Intrinsic::abs
>(m_Value(), m_Value())))
6481 case Intrinsic::cttz
: {
6483 if (match(Op0
, m_Shl(m_One(), m_Value(X
))))
6487 case Intrinsic::ctlz
: {
6489 if (match(Op0
, m_LShr(m_Negative(), m_Value(X
))))
6491 if (match(Op0
, m_AShr(m_Negative(), m_Value())))
6492 return Constant::getNullValue(ReturnType
);
6495 case Intrinsic::ptrmask
: {
6496 if (isa
<PoisonValue
>(Op0
) || isa
<PoisonValue
>(Op1
))
6497 return PoisonValue::get(Op0
->getType());
6499 // NOTE: We can't apply this simplifications based on the value of Op1
6500 // because we need to preserve provenance.
6501 if (Q
.isUndefValue(Op0
) || match(Op0
, m_Zero()))
6502 return Constant::getNullValue(Op0
->getType());
6504 assert(Op1
->getType()->getScalarSizeInBits() ==
6505 Q
.DL
.getIndexTypeSizeInBits(Op0
->getType()) &&
6506 "Invalid mask width");
6507 // If index-width (mask size) is less than pointer-size then mask is
6509 if (match(Op1
, m_PtrToInt(m_Specific(Op0
))))
6512 // NOTE: We may have attributes associated with the return value of the
6513 // llvm.ptrmask intrinsic that will be lost when we just return the
6514 // operand. We should try to preserve them.
6515 if (match(Op1
, m_AllOnes()) || Q
.isUndefValue(Op1
))
6519 if (match(Op1
, m_ImmConstant(C
))) {
6520 KnownBits PtrKnown
= computeKnownBits(Op0
, /*Depth=*/0, Q
);
6521 // See if we only masking off bits we know are already zero due to
6523 APInt IrrelevantPtrBits
=
6524 PtrKnown
.Zero
.zextOrTrunc(C
->getType()->getScalarSizeInBits());
6525 C
= ConstantFoldBinaryOpOperands(
6526 Instruction::Or
, C
, ConstantInt::get(C
->getType(), IrrelevantPtrBits
),
6528 if (C
!= nullptr && C
->isAllOnesValue())
6533 case Intrinsic::smax
:
6534 case Intrinsic::smin
:
6535 case Intrinsic::umax
:
6536 case Intrinsic::umin
: {
6537 // If the arguments are the same, this is a no-op.
6541 // Canonicalize immediate constant operand as Op1.
6542 if (match(Op0
, m_ImmConstant()))
6543 std::swap(Op0
, Op1
);
6545 // Assume undef is the limit value.
6546 if (Q
.isUndefValue(Op1
))
6547 return ConstantInt::get(
6548 ReturnType
, MinMaxIntrinsic::getSaturationPoint(IID
, BitWidth
));
6551 if (match(Op1
, m_APIntAllowPoison(C
))) {
6552 // Clamp to limit value. For example:
6553 // umax(i8 %x, i8 255) --> 255
6554 if (*C
== MinMaxIntrinsic::getSaturationPoint(IID
, BitWidth
))
6555 return ConstantInt::get(ReturnType
, *C
);
6557 // If the constant op is the opposite of the limit value, the other must
6558 // be larger/smaller or equal. For example:
6559 // umin(i8 %x, i8 255) --> %x
6560 if (*C
== MinMaxIntrinsic::getSaturationPoint(
6561 getInverseMinMaxIntrinsic(IID
), BitWidth
))
6564 // Remove nested call if constant operands allow it. Example:
6565 // max (max X, 7), 5 -> max X, 7
6566 auto *MinMax0
= dyn_cast
<IntrinsicInst
>(Op0
);
6567 if (MinMax0
&& MinMax0
->getIntrinsicID() == IID
) {
6568 // TODO: loosen undef/splat restrictions for vector constants.
6569 Value
*M00
= MinMax0
->getOperand(0), *M01
= MinMax0
->getOperand(1);
6570 const APInt
*InnerC
;
6571 if ((match(M00
, m_APInt(InnerC
)) || match(M01
, m_APInt(InnerC
))) &&
6572 ICmpInst::compare(*InnerC
, *C
,
6573 ICmpInst::getNonStrictPredicate(
6574 MinMaxIntrinsic::getPredicate(IID
))))
6579 if (Value
*V
= foldMinMaxSharedOp(IID
, Op0
, Op1
))
6581 if (Value
*V
= foldMinMaxSharedOp(IID
, Op1
, Op0
))
6584 ICmpInst::Predicate Pred
=
6585 ICmpInst::getNonStrictPredicate(MinMaxIntrinsic::getPredicate(IID
));
6586 if (isICmpTrue(Pred
, Op0
, Op1
, Q
.getWithoutUndef(), RecursionLimit
))
6588 if (isICmpTrue(Pred
, Op1
, Op0
, Q
.getWithoutUndef(), RecursionLimit
))
6593 case Intrinsic::scmp
:
6594 case Intrinsic::ucmp
: {
6595 // Fold to a constant if the relationship between operands can be
6596 // established with certainty
6597 if (isICmpTrue(CmpInst::ICMP_EQ
, Op0
, Op1
, Q
, RecursionLimit
))
6598 return Constant::getNullValue(ReturnType
);
6600 ICmpInst::Predicate PredGT
=
6601 IID
== Intrinsic::scmp
? ICmpInst::ICMP_SGT
: ICmpInst::ICMP_UGT
;
6602 if (isICmpTrue(PredGT
, Op0
, Op1
, Q
, RecursionLimit
))
6603 return ConstantInt::get(ReturnType
, 1);
6605 ICmpInst::Predicate PredLT
=
6606 IID
== Intrinsic::scmp
? ICmpInst::ICMP_SLT
: ICmpInst::ICMP_ULT
;
6607 if (isICmpTrue(PredLT
, Op0
, Op1
, Q
, RecursionLimit
))
6608 return ConstantInt::getSigned(ReturnType
, -1);
6612 case Intrinsic::usub_with_overflow
:
6613 case Intrinsic::ssub_with_overflow
:
6614 // X - X -> { 0, false }
6615 // X - undef -> { 0, false }
6616 // undef - X -> { 0, false }
6617 if (Op0
== Op1
|| Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6618 return Constant::getNullValue(ReturnType
);
6620 case Intrinsic::uadd_with_overflow
:
6621 case Intrinsic::sadd_with_overflow
:
6622 // X + undef -> { -1, false }
6623 // undef + x -> { -1, false }
6624 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
)) {
6625 return ConstantStruct::get(
6626 cast
<StructType
>(ReturnType
),
6627 {Constant::getAllOnesValue(ReturnType
->getStructElementType(0)),
6628 Constant::getNullValue(ReturnType
->getStructElementType(1))});
6631 case Intrinsic::umul_with_overflow
:
6632 case Intrinsic::smul_with_overflow
:
6633 // 0 * X -> { 0, false }
6634 // X * 0 -> { 0, false }
6635 if (match(Op0
, m_Zero()) || match(Op1
, m_Zero()))
6636 return Constant::getNullValue(ReturnType
);
6637 // undef * X -> { 0, false }
6638 // X * undef -> { 0, false }
6639 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6640 return Constant::getNullValue(ReturnType
);
6642 case Intrinsic::uadd_sat
:
6643 // sat(MAX + X) -> MAX
6644 // sat(X + MAX) -> MAX
6645 if (match(Op0
, m_AllOnes()) || match(Op1
, m_AllOnes()))
6646 return Constant::getAllOnesValue(ReturnType
);
6648 case Intrinsic::sadd_sat
:
6649 // sat(X + undef) -> -1
6650 // sat(undef + X) -> -1
6651 // For unsigned: Assume undef is MAX, thus we saturate to MAX (-1).
6652 // For signed: Assume undef is ~X, in which case X + ~X = -1.
6653 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6654 return Constant::getAllOnesValue(ReturnType
);
6657 if (match(Op1
, m_Zero()))
6660 if (match(Op0
, m_Zero()))
6663 case Intrinsic::usub_sat
:
6664 // sat(0 - X) -> 0, sat(X - MAX) -> 0
6665 if (match(Op0
, m_Zero()) || match(Op1
, m_AllOnes()))
6666 return Constant::getNullValue(ReturnType
);
6668 case Intrinsic::ssub_sat
:
6669 // X - X -> 0, X - undef -> 0, undef - X -> 0
6670 if (Op0
== Op1
|| Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6671 return Constant::getNullValue(ReturnType
);
6673 if (match(Op1
, m_Zero()))
6676 case Intrinsic::load_relative
:
6677 if (auto *C0
= dyn_cast
<Constant
>(Op0
))
6678 if (auto *C1
= dyn_cast
<Constant
>(Op1
))
6679 return simplifyRelativeLoad(C0
, C1
, Q
.DL
);
6681 case Intrinsic::powi
:
6682 if (auto *Power
= dyn_cast
<ConstantInt
>(Op1
)) {
6683 // powi(x, 0) -> 1.0
6684 if (Power
->isZero())
6685 return ConstantFP::get(Op0
->getType(), 1.0);
6691 case Intrinsic::ldexp
:
6692 return simplifyLdexp(Op0
, Op1
, Q
, false);
6693 case Intrinsic::copysign
:
6694 // copysign X, X --> X
6697 // copysign -X, X --> X
6698 // copysign X, -X --> -X
6699 if (match(Op0
, m_FNeg(m_Specific(Op1
))) ||
6700 match(Op1
, m_FNeg(m_Specific(Op0
))))
6703 case Intrinsic::is_fpclass
: {
6704 if (isa
<PoisonValue
>(Op0
))
6705 return PoisonValue::get(ReturnType
);
6707 uint64_t Mask
= cast
<ConstantInt
>(Op1
)->getZExtValue();
6708 // If all tests are made, it doesn't matter what the value is.
6709 if ((Mask
& fcAllFlags
) == fcAllFlags
)
6710 return ConstantInt::get(ReturnType
, true);
6711 if ((Mask
& fcAllFlags
) == 0)
6712 return ConstantInt::get(ReturnType
, false);
6713 if (Q
.isUndefValue(Op0
))
6714 return UndefValue::get(ReturnType
);
6717 case Intrinsic::maxnum
:
6718 case Intrinsic::minnum
:
6719 case Intrinsic::maximum
:
6720 case Intrinsic::minimum
: {
6721 // If the arguments are the same, this is a no-op.
6725 // Canonicalize constant operand as Op1.
6726 if (isa
<Constant
>(Op0
))
6727 std::swap(Op0
, Op1
);
6729 // If an argument is undef, return the other argument.
6730 if (Q
.isUndefValue(Op1
))
6733 bool PropagateNaN
= IID
== Intrinsic::minimum
|| IID
== Intrinsic::maximum
;
6734 bool IsMin
= IID
== Intrinsic::minimum
|| IID
== Intrinsic::minnum
;
6736 // minnum(X, nan) -> X
6737 // maxnum(X, nan) -> X
6738 // minimum(X, nan) -> nan
6739 // maximum(X, nan) -> nan
6740 if (match(Op1
, m_NaN()))
6741 return PropagateNaN
? propagateNaN(cast
<Constant
>(Op1
)) : Op0
;
6743 // In the following folds, inf can be replaced with the largest finite
6744 // float, if the ninf flag is set.
6746 if (match(Op1
, m_APFloat(C
)) &&
6747 (C
->isInfinity() || (Call
&& Call
->hasNoInfs() && C
->isLargest()))) {
6748 // minnum(X, -inf) -> -inf
6749 // maxnum(X, +inf) -> +inf
6750 // minimum(X, -inf) -> -inf if nnan
6751 // maximum(X, +inf) -> +inf if nnan
6752 if (C
->isNegative() == IsMin
&&
6753 (!PropagateNaN
|| (Call
&& Call
->hasNoNaNs())))
6754 return ConstantFP::get(ReturnType
, *C
);
6756 // minnum(X, +inf) -> X if nnan
6757 // maxnum(X, -inf) -> X if nnan
6758 // minimum(X, +inf) -> X
6759 // maximum(X, -inf) -> X
6760 if (C
->isNegative() != IsMin
&&
6761 (PropagateNaN
|| (Call
&& Call
->hasNoNaNs())))
6765 // Min/max of the same operation with common operand:
6766 // m(m(X, Y)), X --> m(X, Y) (4 commuted variants)
6767 if (Value
*V
= foldMinimumMaximumSharedOp(IID
, Op0
, Op1
))
6769 if (Value
*V
= foldMinimumMaximumSharedOp(IID
, Op1
, Op0
))
6774 case Intrinsic::vector_extract
: {
6775 // (extract_vector (insert_vector _, X, 0), 0) -> X
6776 unsigned IdxN
= cast
<ConstantInt
>(Op1
)->getZExtValue();
6778 if (match(Op0
, m_Intrinsic
<Intrinsic::vector_insert
>(m_Value(), m_Value(X
),
6780 IdxN
== 0 && X
->getType() == ReturnType
)
6792 static Value
*simplifyIntrinsic(CallBase
*Call
, Value
*Callee
,
6793 ArrayRef
<Value
*> Args
,
6794 const SimplifyQuery
&Q
) {
6795 // Operand bundles should not be in Args.
6796 assert(Call
->arg_size() == Args
.size());
6797 unsigned NumOperands
= Args
.size();
6798 Function
*F
= cast
<Function
>(Callee
);
6799 Intrinsic::ID IID
= F
->getIntrinsicID();
6801 // Most of the intrinsics with no operands have some kind of side effect.
6805 case Intrinsic::vscale
: {
6806 Type
*RetTy
= F
->getReturnType();
6807 ConstantRange CR
= getVScaleRange(Call
->getFunction(), 64);
6808 if (const APInt
*C
= CR
.getSingleElement())
6809 return ConstantInt::get(RetTy
, C
->getZExtValue());
6817 if (NumOperands
== 1)
6818 return simplifyUnaryIntrinsic(F
, Args
[0], Q
, Call
);
6820 if (NumOperands
== 2)
6821 return simplifyBinaryIntrinsic(IID
, F
->getReturnType(), Args
[0], Args
[1], Q
,
6824 // Handle intrinsics with 3 or more arguments.
6826 case Intrinsic::masked_load
:
6827 case Intrinsic::masked_gather
: {
6828 Value
*MaskArg
= Args
[2];
6829 Value
*PassthruArg
= Args
[3];
6830 // If the mask is all zeros or undef, the "passthru" argument is the result.
6831 if (maskIsAllZeroOrUndef(MaskArg
))
6835 case Intrinsic::fshl
:
6836 case Intrinsic::fshr
: {
6837 Value
*Op0
= Args
[0], *Op1
= Args
[1], *ShAmtArg
= Args
[2];
6839 // If both operands are undef, the result is undef.
6840 if (Q
.isUndefValue(Op0
) && Q
.isUndefValue(Op1
))
6841 return UndefValue::get(F
->getReturnType());
6843 // If shift amount is undef, assume it is zero.
6844 if (Q
.isUndefValue(ShAmtArg
))
6845 return Args
[IID
== Intrinsic::fshl
? 0 : 1];
6847 const APInt
*ShAmtC
;
6848 if (match(ShAmtArg
, m_APInt(ShAmtC
))) {
6849 // If there's effectively no shift, return the 1st arg or 2nd arg.
6850 APInt BitWidth
= APInt(ShAmtC
->getBitWidth(), ShAmtC
->getBitWidth());
6851 if (ShAmtC
->urem(BitWidth
).isZero())
6852 return Args
[IID
== Intrinsic::fshl
? 0 : 1];
6855 // Rotating zero by anything is zero.
6856 if (match(Op0
, m_Zero()) && match(Op1
, m_Zero()))
6857 return ConstantInt::getNullValue(F
->getReturnType());
6859 // Rotating -1 by anything is -1.
6860 if (match(Op0
, m_AllOnes()) && match(Op1
, m_AllOnes()))
6861 return ConstantInt::getAllOnesValue(F
->getReturnType());
6865 case Intrinsic::experimental_constrained_fma
: {
6866 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6867 if (Value
*V
= simplifyFPOp(Args
, {}, Q
, *FPI
->getExceptionBehavior(),
6868 *FPI
->getRoundingMode()))
6872 case Intrinsic::fma
:
6873 case Intrinsic::fmuladd
: {
6874 if (Value
*V
= simplifyFPOp(Args
, {}, Q
, fp::ebIgnore
,
6875 RoundingMode::NearestTiesToEven
))
6879 case Intrinsic::smul_fix
:
6880 case Intrinsic::smul_fix_sat
: {
6881 Value
*Op0
= Args
[0];
6882 Value
*Op1
= Args
[1];
6883 Value
*Op2
= Args
[2];
6884 Type
*ReturnType
= F
->getReturnType();
6886 // Canonicalize constant operand as Op1 (ConstantFolding handles the case
6887 // when both Op0 and Op1 are constant so we do not care about that special
6889 if (isa
<Constant
>(Op0
))
6890 std::swap(Op0
, Op1
);
6893 if (match(Op1
, m_Zero()))
6894 return Constant::getNullValue(ReturnType
);
6897 if (Q
.isUndefValue(Op1
))
6898 return Constant::getNullValue(ReturnType
);
6900 // X * (1 << Scale) -> X
6902 APInt::getOneBitSet(ReturnType
->getScalarSizeInBits(),
6903 cast
<ConstantInt
>(Op2
)->getZExtValue());
6904 if (ScaledOne
.isNonNegative() && match(Op1
, m_SpecificInt(ScaledOne
)))
6909 case Intrinsic::vector_insert
: {
6910 Value
*Vec
= Args
[0];
6911 Value
*SubVec
= Args
[1];
6912 Value
*Idx
= Args
[2];
6913 Type
*ReturnType
= F
->getReturnType();
6915 // (insert_vector Y, (extract_vector X, 0), 0) -> X
6916 // where: Y is X, or Y is undef
6917 unsigned IdxN
= cast
<ConstantInt
>(Idx
)->getZExtValue();
6920 m_Intrinsic
<Intrinsic::vector_extract
>(m_Value(X
), m_Zero())) &&
6921 (Q
.isUndefValue(Vec
) || Vec
== X
) && IdxN
== 0 &&
6922 X
->getType() == ReturnType
)
6927 case Intrinsic::experimental_constrained_fadd
: {
6928 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6929 return simplifyFAddInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6930 *FPI
->getExceptionBehavior(),
6931 *FPI
->getRoundingMode());
6933 case Intrinsic::experimental_constrained_fsub
: {
6934 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6935 return simplifyFSubInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6936 *FPI
->getExceptionBehavior(),
6937 *FPI
->getRoundingMode());
6939 case Intrinsic::experimental_constrained_fmul
: {
6940 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6941 return simplifyFMulInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6942 *FPI
->getExceptionBehavior(),
6943 *FPI
->getRoundingMode());
6945 case Intrinsic::experimental_constrained_fdiv
: {
6946 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6947 return simplifyFDivInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6948 *FPI
->getExceptionBehavior(),
6949 *FPI
->getRoundingMode());
6951 case Intrinsic::experimental_constrained_frem
: {
6952 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6953 return simplifyFRemInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6954 *FPI
->getExceptionBehavior(),
6955 *FPI
->getRoundingMode());
6957 case Intrinsic::experimental_constrained_ldexp
:
6958 return simplifyLdexp(Args
[0], Args
[1], Q
, true);
6959 case Intrinsic::experimental_gc_relocate
: {
6960 GCRelocateInst
&GCR
= *cast
<GCRelocateInst
>(Call
);
6961 Value
*DerivedPtr
= GCR
.getDerivedPtr();
6962 Value
*BasePtr
= GCR
.getBasePtr();
6964 // Undef is undef, even after relocation.
6965 if (isa
<UndefValue
>(DerivedPtr
) || isa
<UndefValue
>(BasePtr
)) {
6966 return UndefValue::get(GCR
.getType());
6969 if (auto *PT
= dyn_cast
<PointerType
>(GCR
.getType())) {
6970 // For now, the assumption is that the relocation of null will be null
6971 // for most any collector. If this ever changes, a corresponding hook
6972 // should be added to GCStrategy and this code should check it first.
6973 if (isa
<ConstantPointerNull
>(DerivedPtr
)) {
6974 // Use null-pointer of gc_relocate's type to replace it.
6975 return ConstantPointerNull::get(PT
);
6985 static Value
*tryConstantFoldCall(CallBase
*Call
, Value
*Callee
,
6986 ArrayRef
<Value
*> Args
,
6987 const SimplifyQuery
&Q
) {
6988 auto *F
= dyn_cast
<Function
>(Callee
);
6989 if (!F
|| !canConstantFoldCallTo(Call
, F
))
6992 SmallVector
<Constant
*, 4> ConstantArgs
;
6993 ConstantArgs
.reserve(Args
.size());
6994 for (Value
*Arg
: Args
) {
6995 Constant
*C
= dyn_cast
<Constant
>(Arg
);
6997 if (isa
<MetadataAsValue
>(Arg
))
7001 ConstantArgs
.push_back(C
);
7004 return ConstantFoldCall(Call
, F
, ConstantArgs
, Q
.TLI
);
7007 Value
*llvm::simplifyCall(CallBase
*Call
, Value
*Callee
, ArrayRef
<Value
*> Args
,
7008 const SimplifyQuery
&Q
) {
7009 // Args should not contain operand bundle operands.
7010 assert(Call
->arg_size() == Args
.size());
7012 // musttail calls can only be simplified if they are also DCEd.
7013 // As we can't guarantee this here, don't simplify them.
7014 if (Call
->isMustTailCall())
7017 // call undef -> poison
7018 // call null -> poison
7019 if (isa
<UndefValue
>(Callee
) || isa
<ConstantPointerNull
>(Callee
))
7020 return PoisonValue::get(Call
->getType());
7022 if (Value
*V
= tryConstantFoldCall(Call
, Callee
, Args
, Q
))
7025 auto *F
= dyn_cast
<Function
>(Callee
);
7026 if (F
&& F
->isIntrinsic())
7027 if (Value
*Ret
= simplifyIntrinsic(Call
, Callee
, Args
, Q
))
7033 Value
*llvm::simplifyConstrainedFPCall(CallBase
*Call
, const SimplifyQuery
&Q
) {
7034 assert(isa
<ConstrainedFPIntrinsic
>(Call
));
7035 SmallVector
<Value
*, 4> Args(Call
->args());
7036 if (Value
*V
= tryConstantFoldCall(Call
, Call
->getCalledOperand(), Args
, Q
))
7038 if (Value
*Ret
= simplifyIntrinsic(Call
, Call
->getCalledOperand(), Args
, Q
))
7043 /// Given operands for a Freeze, see if we can fold the result.
7044 static Value
*simplifyFreezeInst(Value
*Op0
, const SimplifyQuery
&Q
) {
7045 // Use a utility function defined in ValueTracking.
7046 if (llvm::isGuaranteedNotToBeUndefOrPoison(Op0
, Q
.AC
, Q
.CxtI
, Q
.DT
))
7048 // We have room for improvement.
7052 Value
*llvm::simplifyFreezeInst(Value
*Op0
, const SimplifyQuery
&Q
) {
7053 return ::simplifyFreezeInst(Op0
, Q
);
7056 Value
*llvm::simplifyLoadInst(LoadInst
*LI
, Value
*PtrOp
,
7057 const SimplifyQuery
&Q
) {
7058 if (LI
->isVolatile())
7061 if (auto *PtrOpC
= dyn_cast
<Constant
>(PtrOp
))
7062 return ConstantFoldLoadFromConstPtr(PtrOpC
, LI
->getType(), Q
.DL
);
7064 // We can only fold the load if it is from a constant global with definitive
7065 // initializer. Skip expensive logic if this is not the case.
7066 auto *GV
= dyn_cast
<GlobalVariable
>(getUnderlyingObject(PtrOp
));
7067 if (!GV
|| !GV
->isConstant() || !GV
->hasDefinitiveInitializer())
7070 // If GlobalVariable's initializer is uniform, then return the constant
7071 // regardless of its offset.
7072 if (Constant
*C
= ConstantFoldLoadFromUniformValue(GV
->getInitializer(),
7073 LI
->getType(), Q
.DL
))
7076 // Try to convert operand into a constant by stripping offsets while looking
7077 // through invariant.group intrinsics.
7078 APInt
Offset(Q
.DL
.getIndexTypeSizeInBits(PtrOp
->getType()), 0);
7079 PtrOp
= PtrOp
->stripAndAccumulateConstantOffsets(
7080 Q
.DL
, Offset
, /* AllowNonInbounts */ true,
7081 /* AllowInvariantGroup */ true);
7083 // Index size may have changed due to address space casts.
7084 Offset
= Offset
.sextOrTrunc(Q
.DL
.getIndexTypeSizeInBits(PtrOp
->getType()));
7085 return ConstantFoldLoadFromConstPtr(GV
, LI
->getType(), std::move(Offset
),
7092 /// See if we can compute a simplified version of this instruction.
7093 /// If not, this returns null.
7095 static Value
*simplifyInstructionWithOperands(Instruction
*I
,
7096 ArrayRef
<Value
*> NewOps
,
7097 const SimplifyQuery
&SQ
,
7098 unsigned MaxRecurse
) {
7099 assert(I
->getFunction() && "instruction should be inserted in a function");
7100 assert((!SQ
.CxtI
|| SQ
.CxtI
->getFunction() == I
->getFunction()) &&
7101 "context instruction should be in the same function");
7103 const SimplifyQuery Q
= SQ
.CxtI
? SQ
: SQ
.getWithInstruction(I
);
7105 switch (I
->getOpcode()) {
7107 if (llvm::all_of(NewOps
, [](Value
*V
) { return isa
<Constant
>(V
); })) {
7108 SmallVector
<Constant
*, 8> NewConstOps(NewOps
.size());
7109 transform(NewOps
, NewConstOps
.begin(),
7110 [](Value
*V
) { return cast
<Constant
>(V
); });
7111 return ConstantFoldInstOperands(I
, NewConstOps
, Q
.DL
, Q
.TLI
);
7114 case Instruction::FNeg
:
7115 return simplifyFNegInst(NewOps
[0], I
->getFastMathFlags(), Q
, MaxRecurse
);
7116 case Instruction::FAdd
:
7117 return simplifyFAddInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7119 case Instruction::Add
:
7120 return simplifyAddInst(
7121 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
7122 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
7123 case Instruction::FSub
:
7124 return simplifyFSubInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7126 case Instruction::Sub
:
7127 return simplifySubInst(
7128 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
7129 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
7130 case Instruction::FMul
:
7131 return simplifyFMulInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7133 case Instruction::Mul
:
7134 return simplifyMulInst(
7135 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
7136 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
7137 case Instruction::SDiv
:
7138 return simplifySDivInst(NewOps
[0], NewOps
[1],
7139 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7141 case Instruction::UDiv
:
7142 return simplifyUDivInst(NewOps
[0], NewOps
[1],
7143 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7145 case Instruction::FDiv
:
7146 return simplifyFDivInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7148 case Instruction::SRem
:
7149 return simplifySRemInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7150 case Instruction::URem
:
7151 return simplifyURemInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7152 case Instruction::FRem
:
7153 return simplifyFRemInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7155 case Instruction::Shl
:
7156 return simplifyShlInst(
7157 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
7158 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
7159 case Instruction::LShr
:
7160 return simplifyLShrInst(NewOps
[0], NewOps
[1],
7161 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7163 case Instruction::AShr
:
7164 return simplifyAShrInst(NewOps
[0], NewOps
[1],
7165 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7167 case Instruction::And
:
7168 return simplifyAndInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7169 case Instruction::Or
:
7170 return simplifyOrInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7171 case Instruction::Xor
:
7172 return simplifyXorInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7173 case Instruction::ICmp
:
7174 return simplifyICmpInst(cast
<ICmpInst
>(I
)->getCmpPredicate(), NewOps
[0],
7175 NewOps
[1], Q
, MaxRecurse
);
7176 case Instruction::FCmp
:
7177 return simplifyFCmpInst(cast
<FCmpInst
>(I
)->getPredicate(), NewOps
[0],
7178 NewOps
[1], I
->getFastMathFlags(), Q
, MaxRecurse
);
7179 case Instruction::Select
:
7180 return simplifySelectInst(NewOps
[0], NewOps
[1], NewOps
[2], Q
, MaxRecurse
);
7181 case Instruction::GetElementPtr
: {
7182 auto *GEPI
= cast
<GetElementPtrInst
>(I
);
7183 return simplifyGEPInst(GEPI
->getSourceElementType(), NewOps
[0],
7184 ArrayRef(NewOps
).slice(1), GEPI
->getNoWrapFlags(), Q
,
7187 case Instruction::InsertValue
: {
7188 InsertValueInst
*IV
= cast
<InsertValueInst
>(I
);
7189 return simplifyInsertValueInst(NewOps
[0], NewOps
[1], IV
->getIndices(), Q
,
7192 case Instruction::InsertElement
:
7193 return simplifyInsertElementInst(NewOps
[0], NewOps
[1], NewOps
[2], Q
);
7194 case Instruction::ExtractValue
: {
7195 auto *EVI
= cast
<ExtractValueInst
>(I
);
7196 return simplifyExtractValueInst(NewOps
[0], EVI
->getIndices(), Q
,
7199 case Instruction::ExtractElement
:
7200 return simplifyExtractElementInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7201 case Instruction::ShuffleVector
: {
7202 auto *SVI
= cast
<ShuffleVectorInst
>(I
);
7203 return simplifyShuffleVectorInst(NewOps
[0], NewOps
[1],
7204 SVI
->getShuffleMask(), SVI
->getType(), Q
,
7207 case Instruction::PHI
:
7208 return simplifyPHINode(cast
<PHINode
>(I
), NewOps
, Q
);
7209 case Instruction::Call
:
7210 return simplifyCall(
7211 cast
<CallInst
>(I
), NewOps
.back(),
7212 NewOps
.drop_back(1 + cast
<CallInst
>(I
)->getNumTotalBundleOperands()), Q
);
7213 case Instruction::Freeze
:
7214 return llvm::simplifyFreezeInst(NewOps
[0], Q
);
7215 #define HANDLE_CAST_INST(num, opc, clas) case Instruction::opc:
7216 #include "llvm/IR/Instruction.def"
7217 #undef HANDLE_CAST_INST
7218 return simplifyCastInst(I
->getOpcode(), NewOps
[0], I
->getType(), Q
,
7220 case Instruction::Alloca
:
7221 // No simplifications for Alloca and it can't be constant folded.
7223 case Instruction::Load
:
7224 return simplifyLoadInst(cast
<LoadInst
>(I
), NewOps
[0], Q
);
7228 Value
*llvm::simplifyInstructionWithOperands(Instruction
*I
,
7229 ArrayRef
<Value
*> NewOps
,
7230 const SimplifyQuery
&SQ
) {
7231 assert(NewOps
.size() == I
->getNumOperands() &&
7232 "Number of operands should match the instruction!");
7233 return ::simplifyInstructionWithOperands(I
, NewOps
, SQ
, RecursionLimit
);
7236 Value
*llvm::simplifyInstruction(Instruction
*I
, const SimplifyQuery
&SQ
) {
7237 SmallVector
<Value
*, 8> Ops(I
->operands());
7238 Value
*Result
= ::simplifyInstructionWithOperands(I
, Ops
, SQ
, RecursionLimit
);
7240 /// If called on unreachable code, the instruction may simplify to itself.
7241 /// Make life easier for users by detecting that case here, and returning a
7242 /// safe value instead.
7243 return Result
== I
? PoisonValue::get(I
->getType()) : Result
;
7246 /// Implementation of recursive simplification through an instruction's
7249 /// This is the common implementation of the recursive simplification routines.
7250 /// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
7251 /// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
7252 /// instructions to process and attempt to simplify it using
7253 /// InstructionSimplify. Recursively visited users which could not be
7254 /// simplified themselves are to the optional UnsimplifiedUsers set for
7255 /// further processing by the caller.
7257 /// This routine returns 'true' only when *it* simplifies something. The passed
7258 /// in simplified value does not count toward this.
7259 static bool replaceAndRecursivelySimplifyImpl(
7260 Instruction
*I
, Value
*SimpleV
, const TargetLibraryInfo
*TLI
,
7261 const DominatorTree
*DT
, AssumptionCache
*AC
,
7262 SmallSetVector
<Instruction
*, 8> *UnsimplifiedUsers
= nullptr) {
7263 bool Simplified
= false;
7264 SmallSetVector
<Instruction
*, 8> Worklist
;
7265 const DataLayout
&DL
= I
->getDataLayout();
7267 // If we have an explicit value to collapse to, do that round of the
7268 // simplification loop by hand initially.
7270 for (User
*U
: I
->users())
7272 Worklist
.insert(cast
<Instruction
>(U
));
7274 // Replace the instruction with its simplified value.
7275 I
->replaceAllUsesWith(SimpleV
);
7277 if (!I
->isEHPad() && !I
->isTerminator() && !I
->mayHaveSideEffects())
7278 I
->eraseFromParent();
7283 // Note that we must test the size on each iteration, the worklist can grow.
7284 for (unsigned Idx
= 0; Idx
!= Worklist
.size(); ++Idx
) {
7287 // See if this instruction simplifies.
7288 SimpleV
= simplifyInstruction(I
, {DL
, TLI
, DT
, AC
});
7290 if (UnsimplifiedUsers
)
7291 UnsimplifiedUsers
->insert(I
);
7297 // Stash away all the uses of the old instruction so we can check them for
7298 // recursive simplifications after a RAUW. This is cheaper than checking all
7299 // uses of To on the recursive step in most cases.
7300 for (User
*U
: I
->users())
7301 Worklist
.insert(cast
<Instruction
>(U
));
7303 // Replace the instruction with its simplified value.
7304 I
->replaceAllUsesWith(SimpleV
);
7306 if (!I
->isEHPad() && !I
->isTerminator() && !I
->mayHaveSideEffects())
7307 I
->eraseFromParent();
7312 bool llvm::replaceAndRecursivelySimplify(
7313 Instruction
*I
, Value
*SimpleV
, const TargetLibraryInfo
*TLI
,
7314 const DominatorTree
*DT
, AssumptionCache
*AC
,
7315 SmallSetVector
<Instruction
*, 8> *UnsimplifiedUsers
) {
7316 assert(I
!= SimpleV
&& "replaceAndRecursivelySimplify(X,X) is not valid!");
7317 assert(SimpleV
&& "Must provide a simplified value.");
7318 return replaceAndRecursivelySimplifyImpl(I
, SimpleV
, TLI
, DT
, AC
,
7323 const SimplifyQuery
getBestSimplifyQuery(Pass
&P
, Function
&F
) {
7324 auto *DTWP
= P
.getAnalysisIfAvailable
<DominatorTreeWrapperPass
>();
7325 auto *DT
= DTWP
? &DTWP
->getDomTree() : nullptr;
7326 auto *TLIWP
= P
.getAnalysisIfAvailable
<TargetLibraryInfoWrapperPass
>();
7327 auto *TLI
= TLIWP
? &TLIWP
->getTLI(F
) : nullptr;
7328 auto *ACWP
= P
.getAnalysisIfAvailable
<AssumptionCacheTracker
>();
7329 auto *AC
= ACWP
? &ACWP
->getAssumptionCache(F
) : nullptr;
7330 return {F
.getDataLayout(), TLI
, DT
, AC
};
7333 const SimplifyQuery
getBestSimplifyQuery(LoopStandardAnalysisResults
&AR
,
7334 const DataLayout
&DL
) {
7335 return {DL
, &AR
.TLI
, &AR
.DT
, &AR
.AC
};
7338 template <class T
, class... TArgs
>
7339 const SimplifyQuery
getBestSimplifyQuery(AnalysisManager
<T
, TArgs
...> &AM
,
7341 auto *DT
= AM
.template getCachedResult
<DominatorTreeAnalysis
>(F
);
7342 auto *TLI
= AM
.template getCachedResult
<TargetLibraryAnalysis
>(F
);
7343 auto *AC
= AM
.template getCachedResult
<AssumptionAnalysis
>(F
);
7344 return {F
.getDataLayout(), TLI
, DT
, AC
};
7346 template const SimplifyQuery
getBestSimplifyQuery(AnalysisManager
<Function
> &,
7349 bool SimplifyQuery::isUndefValue(Value
*V
) const {
7353 return match(V
, m_Undef());
7358 void InstSimplifyFolder::anchor() {}