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/LoopAnalysisManager.h"
31 #include "llvm/Analysis/MemoryBuiltins.h"
32 #include "llvm/Analysis/OverflowInstAnalysis.h"
33 #include "llvm/Analysis/ValueTracking.h"
34 #include "llvm/Analysis/VectorUtils.h"
35 #include "llvm/IR/ConstantRange.h"
36 #include "llvm/IR/DataLayout.h"
37 #include "llvm/IR/Dominators.h"
38 #include "llvm/IR/InstrTypes.h"
39 #include "llvm/IR/Instructions.h"
40 #include "llvm/IR/Operator.h"
41 #include "llvm/IR/PatternMatch.h"
42 #include "llvm/Support/KnownBits.h"
46 using namespace llvm::PatternMatch
;
48 #define DEBUG_TYPE "instsimplify"
50 enum { RecursionLimit
= 3 };
52 STATISTIC(NumExpand
, "Number of expansions");
53 STATISTIC(NumReassoc
, "Number of reassociations");
55 static Value
*simplifyAndInst(Value
*, Value
*, const SimplifyQuery
&,
57 static Value
*simplifyUnOp(unsigned, Value
*, const SimplifyQuery
&, unsigned);
58 static Value
*simplifyFPUnOp(unsigned, Value
*, const FastMathFlags
&,
59 const SimplifyQuery
&, unsigned);
60 static Value
*simplifyBinOp(unsigned, Value
*, Value
*, const SimplifyQuery
&,
62 static Value
*simplifyBinOp(unsigned, Value
*, Value
*, const FastMathFlags
&,
63 const SimplifyQuery
&, unsigned);
64 static Value
*simplifyCmpInst(unsigned, Value
*, Value
*, const SimplifyQuery
&,
66 static Value
*simplifyICmpInst(unsigned Predicate
, Value
*LHS
, Value
*RHS
,
67 const SimplifyQuery
&Q
, unsigned MaxRecurse
);
68 static Value
*simplifyOrInst(Value
*, Value
*, const SimplifyQuery
&, unsigned);
69 static Value
*simplifyXorInst(Value
*, Value
*, const SimplifyQuery
&,
71 static Value
*simplifyCastInst(unsigned, Value
*, Type
*, const SimplifyQuery
&,
73 static Value
*simplifyGEPInst(Type
*, Value
*, ArrayRef
<Value
*>, bool,
74 const SimplifyQuery
&, unsigned);
75 static Value
*simplifySelectInst(Value
*, Value
*, Value
*,
76 const SimplifyQuery
&, unsigned);
77 static Value
*simplifyInstructionWithOperands(Instruction
*I
,
78 ArrayRef
<Value
*> NewOps
,
79 const SimplifyQuery
&SQ
,
82 static Value
*foldSelectWithBinaryOp(Value
*Cond
, Value
*TrueVal
,
84 BinaryOperator::BinaryOps BinOpCode
;
85 if (auto *BO
= dyn_cast
<BinaryOperator
>(Cond
))
86 BinOpCode
= BO
->getOpcode();
90 CmpInst::Predicate ExpectedPred
, Pred1
, Pred2
;
91 if (BinOpCode
== BinaryOperator::Or
) {
92 ExpectedPred
= ICmpInst::ICMP_NE
;
93 } else if (BinOpCode
== BinaryOperator::And
) {
94 ExpectedPred
= ICmpInst::ICMP_EQ
;
98 // %A = icmp eq %TV, %FV
99 // %B = icmp eq %X, %Y (and one of these is a select operand)
101 // %D = select %C, %TV, %FV
105 // %A = icmp ne %TV, %FV
106 // %B = icmp ne %X, %Y (and one of these is a select operand)
108 // %D = select %C, %TV, %FV
112 if (!match(Cond
, m_c_BinOp(m_c_ICmp(Pred1
, m_Specific(TrueVal
),
113 m_Specific(FalseVal
)),
114 m_ICmp(Pred2
, m_Value(X
), m_Value(Y
)))) ||
115 Pred1
!= Pred2
|| Pred1
!= ExpectedPred
)
118 if (X
== TrueVal
|| X
== FalseVal
|| Y
== TrueVal
|| Y
== FalseVal
)
119 return BinOpCode
== BinaryOperator::Or
? TrueVal
: FalseVal
;
124 /// For a boolean type or a vector of boolean type, return false or a vector
125 /// with every element false.
126 static Constant
*getFalse(Type
*Ty
) { return ConstantInt::getFalse(Ty
); }
128 /// For a boolean type or a vector of boolean type, return true or a vector
129 /// with every element true.
130 static Constant
*getTrue(Type
*Ty
) { return ConstantInt::getTrue(Ty
); }
132 /// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"?
133 static bool isSameCompare(Value
*V
, CmpInst::Predicate Pred
, Value
*LHS
,
135 CmpInst
*Cmp
= dyn_cast
<CmpInst
>(V
);
138 CmpInst::Predicate CPred
= Cmp
->getPredicate();
139 Value
*CLHS
= Cmp
->getOperand(0), *CRHS
= Cmp
->getOperand(1);
140 if (CPred
== Pred
&& CLHS
== LHS
&& CRHS
== RHS
)
142 return CPred
== CmpInst::getSwappedPredicate(Pred
) && CLHS
== RHS
&&
146 /// Simplify comparison with true or false branch of select:
147 /// %sel = select i1 %cond, i32 %tv, i32 %fv
148 /// %cmp = icmp sle i32 %sel, %rhs
149 /// Compose new comparison by substituting %sel with either %tv or %fv
150 /// and see if it simplifies.
151 static Value
*simplifyCmpSelCase(CmpInst::Predicate Pred
, Value
*LHS
,
152 Value
*RHS
, Value
*Cond
,
153 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
154 Constant
*TrueOrFalse
) {
155 Value
*SimplifiedCmp
= simplifyCmpInst(Pred
, LHS
, RHS
, Q
, MaxRecurse
);
156 if (SimplifiedCmp
== Cond
) {
157 // %cmp simplified to the select condition (%cond).
159 } else if (!SimplifiedCmp
&& isSameCompare(Cond
, Pred
, LHS
, RHS
)) {
160 // It didn't simplify. However, if composed comparison is equivalent
161 // to the select condition (%cond) then we can replace it.
164 return SimplifiedCmp
;
167 /// Simplify comparison with true branch of select
168 static Value
*simplifyCmpSelTrueCase(CmpInst::Predicate Pred
, Value
*LHS
,
169 Value
*RHS
, Value
*Cond
,
170 const SimplifyQuery
&Q
,
171 unsigned MaxRecurse
) {
172 return simplifyCmpSelCase(Pred
, LHS
, RHS
, Cond
, Q
, MaxRecurse
,
173 getTrue(Cond
->getType()));
176 /// Simplify comparison with false branch of select
177 static Value
*simplifyCmpSelFalseCase(CmpInst::Predicate Pred
, Value
*LHS
,
178 Value
*RHS
, Value
*Cond
,
179 const SimplifyQuery
&Q
,
180 unsigned MaxRecurse
) {
181 return simplifyCmpSelCase(Pred
, LHS
, RHS
, Cond
, Q
, MaxRecurse
,
182 getFalse(Cond
->getType()));
185 /// We know comparison with both branches of select can be simplified, but they
186 /// are not equal. This routine handles some logical simplifications.
187 static Value
*handleOtherCmpSelSimplifications(Value
*TCmp
, Value
*FCmp
,
189 const SimplifyQuery
&Q
,
190 unsigned MaxRecurse
) {
191 // If the false value simplified to false, then the result of the compare
192 // is equal to "Cond && TCmp". This also catches the case when the false
193 // value simplified to false and the true value to true, returning "Cond".
194 // Folding select to and/or isn't poison-safe in general; impliesPoison
195 // checks whether folding it does not convert a well-defined value into
197 if (match(FCmp
, m_Zero()) && impliesPoison(TCmp
, Cond
))
198 if (Value
*V
= simplifyAndInst(Cond
, TCmp
, Q
, MaxRecurse
))
200 // If the true value simplified to true, then the result of the compare
201 // is equal to "Cond || FCmp".
202 if (match(TCmp
, m_One()) && impliesPoison(FCmp
, Cond
))
203 if (Value
*V
= simplifyOrInst(Cond
, FCmp
, Q
, MaxRecurse
))
205 // Finally, if the false value simplified to true and the true value to
206 // false, then the result of the compare is equal to "!Cond".
207 if (match(FCmp
, m_One()) && match(TCmp
, m_Zero()))
208 if (Value
*V
= simplifyXorInst(
209 Cond
, Constant::getAllOnesValue(Cond
->getType()), Q
, MaxRecurse
))
214 /// Does the given value dominate the specified phi node?
215 static bool valueDominatesPHI(Value
*V
, PHINode
*P
, const DominatorTree
*DT
) {
216 Instruction
*I
= dyn_cast
<Instruction
>(V
);
218 // Arguments and constants dominate all instructions.
221 // If we have a DominatorTree then do a precise test.
223 return DT
->dominates(I
, P
);
225 // Otherwise, if the instruction is in the entry block and is not an invoke,
226 // then it obviously dominates all phi nodes.
227 if (I
->getParent()->isEntryBlock() && !isa
<InvokeInst
>(I
) &&
234 /// Try to simplify a binary operator of form "V op OtherOp" where V is
235 /// "(B0 opex B1)" by distributing 'op' across 'opex' as
236 /// "(B0 op OtherOp) opex (B1 op OtherOp)".
237 static Value
*expandBinOp(Instruction::BinaryOps Opcode
, Value
*V
,
238 Value
*OtherOp
, Instruction::BinaryOps OpcodeToExpand
,
239 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
240 auto *B
= dyn_cast
<BinaryOperator
>(V
);
241 if (!B
|| B
->getOpcode() != OpcodeToExpand
)
243 Value
*B0
= B
->getOperand(0), *B1
= B
->getOperand(1);
245 simplifyBinOp(Opcode
, B0
, OtherOp
, Q
.getWithoutUndef(), MaxRecurse
);
249 simplifyBinOp(Opcode
, B1
, OtherOp
, Q
.getWithoutUndef(), MaxRecurse
);
253 // Does the expanded pair of binops simplify to the existing binop?
254 if ((L
== B0
&& R
== B1
) ||
255 (Instruction::isCommutative(OpcodeToExpand
) && L
== B1
&& R
== B0
)) {
260 // Otherwise, return "L op' R" if it simplifies.
261 Value
*S
= simplifyBinOp(OpcodeToExpand
, L
, R
, Q
, MaxRecurse
);
269 /// Try to simplify binops of form "A op (B op' C)" or the commuted variant by
270 /// distributing op over op'.
271 static Value
*expandCommutativeBinOp(Instruction::BinaryOps Opcode
, Value
*L
,
273 Instruction::BinaryOps OpcodeToExpand
,
274 const SimplifyQuery
&Q
,
275 unsigned MaxRecurse
) {
276 // Recursion is always used, so bail out at once if we already hit the limit.
280 if (Value
*V
= expandBinOp(Opcode
, L
, R
, OpcodeToExpand
, Q
, MaxRecurse
))
282 if (Value
*V
= expandBinOp(Opcode
, R
, L
, OpcodeToExpand
, Q
, MaxRecurse
))
287 /// Generic simplifications for associative binary operations.
288 /// Returns the simpler value, or null if none was found.
289 static Value
*simplifyAssociativeBinOp(Instruction::BinaryOps Opcode
,
290 Value
*LHS
, Value
*RHS
,
291 const SimplifyQuery
&Q
,
292 unsigned MaxRecurse
) {
293 assert(Instruction::isAssociative(Opcode
) && "Not an associative operation!");
295 // Recursion is always used, so bail out at once if we already hit the limit.
299 BinaryOperator
*Op0
= dyn_cast
<BinaryOperator
>(LHS
);
300 BinaryOperator
*Op1
= dyn_cast
<BinaryOperator
>(RHS
);
302 // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely.
303 if (Op0
&& Op0
->getOpcode() == Opcode
) {
304 Value
*A
= Op0
->getOperand(0);
305 Value
*B
= Op0
->getOperand(1);
308 // Does "B op C" simplify?
309 if (Value
*V
= simplifyBinOp(Opcode
, B
, C
, Q
, MaxRecurse
)) {
310 // It does! Return "A op V" if it simplifies or is already available.
311 // If V equals B then "A op V" is just the LHS.
314 // Otherwise return "A op V" if it simplifies.
315 if (Value
*W
= simplifyBinOp(Opcode
, A
, V
, Q
, MaxRecurse
)) {
322 // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely.
323 if (Op1
&& Op1
->getOpcode() == Opcode
) {
325 Value
*B
= Op1
->getOperand(0);
326 Value
*C
= Op1
->getOperand(1);
328 // Does "A op B" simplify?
329 if (Value
*V
= simplifyBinOp(Opcode
, A
, B
, Q
, MaxRecurse
)) {
330 // It does! Return "V op C" if it simplifies or is already available.
331 // If V equals B then "V op C" is just the RHS.
334 // Otherwise return "V op C" if it simplifies.
335 if (Value
*W
= simplifyBinOp(Opcode
, V
, C
, Q
, MaxRecurse
)) {
342 // The remaining transforms require commutativity as well as associativity.
343 if (!Instruction::isCommutative(Opcode
))
346 // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely.
347 if (Op0
&& Op0
->getOpcode() == Opcode
) {
348 Value
*A
= Op0
->getOperand(0);
349 Value
*B
= Op0
->getOperand(1);
352 // Does "C op A" simplify?
353 if (Value
*V
= simplifyBinOp(Opcode
, C
, A
, Q
, MaxRecurse
)) {
354 // It does! Return "V op B" if it simplifies or is already available.
355 // If V equals A then "V op B" is just the LHS.
358 // Otherwise return "V op B" if it simplifies.
359 if (Value
*W
= simplifyBinOp(Opcode
, V
, B
, Q
, MaxRecurse
)) {
366 // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely.
367 if (Op1
&& Op1
->getOpcode() == Opcode
) {
369 Value
*B
= Op1
->getOperand(0);
370 Value
*C
= Op1
->getOperand(1);
372 // Does "C op A" simplify?
373 if (Value
*V
= simplifyBinOp(Opcode
, C
, A
, Q
, MaxRecurse
)) {
374 // It does! Return "B op V" if it simplifies or is already available.
375 // If V equals C then "B op V" is just the RHS.
378 // Otherwise return "B op V" if it simplifies.
379 if (Value
*W
= simplifyBinOp(Opcode
, B
, V
, Q
, MaxRecurse
)) {
389 /// In the case of a binary operation with a select instruction as an operand,
390 /// try to simplify the binop by seeing whether evaluating it on both branches
391 /// of the select results in the same value. Returns the common value if so,
392 /// otherwise returns null.
393 static Value
*threadBinOpOverSelect(Instruction::BinaryOps Opcode
, Value
*LHS
,
394 Value
*RHS
, const SimplifyQuery
&Q
,
395 unsigned MaxRecurse
) {
396 // Recursion is always used, so bail out at once if we already hit the limit.
401 if (isa
<SelectInst
>(LHS
)) {
402 SI
= cast
<SelectInst
>(LHS
);
404 assert(isa
<SelectInst
>(RHS
) && "No select instruction operand!");
405 SI
= cast
<SelectInst
>(RHS
);
408 // Evaluate the BinOp on the true and false branches of the select.
412 TV
= simplifyBinOp(Opcode
, SI
->getTrueValue(), RHS
, Q
, MaxRecurse
);
413 FV
= simplifyBinOp(Opcode
, SI
->getFalseValue(), RHS
, Q
, MaxRecurse
);
415 TV
= simplifyBinOp(Opcode
, LHS
, SI
->getTrueValue(), Q
, MaxRecurse
);
416 FV
= simplifyBinOp(Opcode
, LHS
, SI
->getFalseValue(), Q
, MaxRecurse
);
419 // If they simplified to the same value, then return the common value.
420 // If they both failed to simplify then return null.
424 // If one branch simplified to undef, return the other one.
425 if (TV
&& Q
.isUndefValue(TV
))
427 if (FV
&& Q
.isUndefValue(FV
))
430 // If applying the operation did not change the true and false select values,
431 // then the result of the binop is the select itself.
432 if (TV
== SI
->getTrueValue() && FV
== SI
->getFalseValue())
435 // If one branch simplified and the other did not, and the simplified
436 // value is equal to the unsimplified one, return the simplified value.
437 // For example, select (cond, X, X & Z) & Z -> X & Z.
438 if ((FV
&& !TV
) || (TV
&& !FV
)) {
439 // Check that the simplified value has the form "X op Y" where "op" is the
440 // same as the original operation.
441 Instruction
*Simplified
= dyn_cast
<Instruction
>(FV
? FV
: TV
);
442 if (Simplified
&& Simplified
->getOpcode() == unsigned(Opcode
)) {
443 // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS".
444 // We already know that "op" is the same as for the simplified value. See
445 // if the operands match too. If so, return the simplified value.
446 Value
*UnsimplifiedBranch
= FV
? SI
->getTrueValue() : SI
->getFalseValue();
447 Value
*UnsimplifiedLHS
= SI
== LHS
? UnsimplifiedBranch
: LHS
;
448 Value
*UnsimplifiedRHS
= SI
== LHS
? RHS
: UnsimplifiedBranch
;
449 if (Simplified
->getOperand(0) == UnsimplifiedLHS
&&
450 Simplified
->getOperand(1) == UnsimplifiedRHS
)
452 if (Simplified
->isCommutative() &&
453 Simplified
->getOperand(1) == UnsimplifiedLHS
&&
454 Simplified
->getOperand(0) == UnsimplifiedRHS
)
462 /// In the case of a comparison with a select instruction, try to simplify the
463 /// comparison by seeing whether both branches of the select result in the same
464 /// value. Returns the common value if so, otherwise returns null.
465 /// For example, if we have:
466 /// %tmp = select i1 %cmp, i32 1, i32 2
467 /// %cmp1 = icmp sle i32 %tmp, 3
468 /// We can simplify %cmp1 to true, because both branches of select are
469 /// less than 3. We compose new comparison by substituting %tmp with both
470 /// branches of select and see if it can be simplified.
471 static Value
*threadCmpOverSelect(CmpInst::Predicate Pred
, Value
*LHS
,
472 Value
*RHS
, const SimplifyQuery
&Q
,
473 unsigned MaxRecurse
) {
474 // Recursion is always used, so bail out at once if we already hit the limit.
478 // Make sure the select is on the LHS.
479 if (!isa
<SelectInst
>(LHS
)) {
481 Pred
= CmpInst::getSwappedPredicate(Pred
);
483 assert(isa
<SelectInst
>(LHS
) && "Not comparing with a select instruction!");
484 SelectInst
*SI
= cast
<SelectInst
>(LHS
);
485 Value
*Cond
= SI
->getCondition();
486 Value
*TV
= SI
->getTrueValue();
487 Value
*FV
= SI
->getFalseValue();
489 // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it.
490 // Does "cmp TV, RHS" simplify?
491 Value
*TCmp
= simplifyCmpSelTrueCase(Pred
, TV
, RHS
, Cond
, Q
, MaxRecurse
);
495 // Does "cmp FV, RHS" simplify?
496 Value
*FCmp
= simplifyCmpSelFalseCase(Pred
, FV
, RHS
, Cond
, Q
, MaxRecurse
);
500 // If both sides simplified to the same value, then use it as the result of
501 // the original comparison.
505 // The remaining cases only make sense if the select condition has the same
506 // type as the result of the comparison, so bail out if this is not so.
507 if (Cond
->getType()->isVectorTy() == RHS
->getType()->isVectorTy())
508 return handleOtherCmpSelSimplifications(TCmp
, FCmp
, Cond
, Q
, MaxRecurse
);
513 /// In the case of a binary operation with an operand that is a PHI instruction,
514 /// try to simplify the binop by seeing whether evaluating it on the incoming
515 /// phi values yields the same result for every value. If so returns the common
516 /// value, otherwise returns null.
517 static Value
*threadBinOpOverPHI(Instruction::BinaryOps Opcode
, Value
*LHS
,
518 Value
*RHS
, const SimplifyQuery
&Q
,
519 unsigned MaxRecurse
) {
520 // Recursion is always used, so bail out at once if we already hit the limit.
525 if (isa
<PHINode
>(LHS
)) {
526 PI
= cast
<PHINode
>(LHS
);
527 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
528 if (!valueDominatesPHI(RHS
, PI
, Q
.DT
))
531 assert(isa
<PHINode
>(RHS
) && "No PHI instruction operand!");
532 PI
= cast
<PHINode
>(RHS
);
533 // Bail out if LHS and the phi may be mutually interdependent due to a loop.
534 if (!valueDominatesPHI(LHS
, PI
, Q
.DT
))
538 // Evaluate the BinOp on the incoming phi values.
539 Value
*CommonValue
= nullptr;
540 for (Use
&Incoming
: PI
->incoming_values()) {
541 // If the incoming value is the phi node itself, it can safely be skipped.
544 Instruction
*InTI
= PI
->getIncomingBlock(Incoming
)->getTerminator();
546 ? simplifyBinOp(Opcode
, Incoming
, RHS
,
547 Q
.getWithInstruction(InTI
), MaxRecurse
)
548 : simplifyBinOp(Opcode
, LHS
, Incoming
,
549 Q
.getWithInstruction(InTI
), MaxRecurse
);
550 // If the operation failed to simplify, or simplified to a different value
551 // to previously, then give up.
552 if (!V
|| (CommonValue
&& V
!= CommonValue
))
560 /// In the case of a comparison with a PHI instruction, try to simplify the
561 /// comparison by seeing whether comparing with all of the incoming phi values
562 /// yields the same result every time. If so returns the common result,
563 /// otherwise returns null.
564 static Value
*threadCmpOverPHI(CmpInst::Predicate Pred
, Value
*LHS
, Value
*RHS
,
565 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
566 // Recursion is always used, so bail out at once if we already hit the limit.
570 // Make sure the phi is on the LHS.
571 if (!isa
<PHINode
>(LHS
)) {
573 Pred
= CmpInst::getSwappedPredicate(Pred
);
575 assert(isa
<PHINode
>(LHS
) && "Not comparing with a phi instruction!");
576 PHINode
*PI
= cast
<PHINode
>(LHS
);
578 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
579 if (!valueDominatesPHI(RHS
, PI
, Q
.DT
))
582 // Evaluate the BinOp on the incoming phi values.
583 Value
*CommonValue
= nullptr;
584 for (unsigned u
= 0, e
= PI
->getNumIncomingValues(); u
< e
; ++u
) {
585 Value
*Incoming
= PI
->getIncomingValue(u
);
586 Instruction
*InTI
= PI
->getIncomingBlock(u
)->getTerminator();
587 // If the incoming value is the phi node itself, it can safely be skipped.
590 // Change the context instruction to the "edge" that flows into the phi.
591 // This is important because that is where incoming is actually "evaluated"
592 // even though it is used later somewhere else.
593 Value
*V
= simplifyCmpInst(Pred
, Incoming
, RHS
, Q
.getWithInstruction(InTI
),
595 // If the operation failed to simplify, or simplified to a different value
596 // to previously, then give up.
597 if (!V
|| (CommonValue
&& V
!= CommonValue
))
605 static Constant
*foldOrCommuteConstant(Instruction::BinaryOps Opcode
,
606 Value
*&Op0
, Value
*&Op1
,
607 const SimplifyQuery
&Q
) {
608 if (auto *CLHS
= dyn_cast
<Constant
>(Op0
)) {
609 if (auto *CRHS
= dyn_cast
<Constant
>(Op1
)) {
613 case Instruction::FAdd
:
614 case Instruction::FSub
:
615 case Instruction::FMul
:
616 case Instruction::FDiv
:
617 case Instruction::FRem
:
618 if (Q
.CxtI
!= nullptr)
619 return ConstantFoldFPInstOperands(Opcode
, CLHS
, CRHS
, Q
.DL
, Q
.CxtI
);
621 return ConstantFoldBinaryOpOperands(Opcode
, CLHS
, CRHS
, Q
.DL
);
624 // Canonicalize the constant to the RHS if this is a commutative operation.
625 if (Instruction::isCommutative(Opcode
))
631 /// Given operands for an Add, see if we can fold the result.
632 /// If not, this returns null.
633 static Value
*simplifyAddInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
634 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
635 if (Constant
*C
= foldOrCommuteConstant(Instruction::Add
, Op0
, Op1
, Q
))
638 // X + poison -> poison
639 if (isa
<PoisonValue
>(Op1
))
642 // X + undef -> undef
643 if (Q
.isUndefValue(Op1
))
647 if (match(Op1
, m_Zero()))
650 // If two operands are negative, return 0.
651 if (isKnownNegation(Op0
, Op1
))
652 return Constant::getNullValue(Op0
->getType());
658 if (match(Op1
, m_Sub(m_Value(Y
), m_Specific(Op0
))) ||
659 match(Op0
, m_Sub(m_Value(Y
), m_Specific(Op1
))))
662 // X + ~X -> -1 since ~X = -X-1
663 Type
*Ty
= Op0
->getType();
664 if (match(Op0
, m_Not(m_Specific(Op1
))) || match(Op1
, m_Not(m_Specific(Op0
))))
665 return Constant::getAllOnesValue(Ty
);
667 // add nsw/nuw (xor Y, signmask), signmask --> Y
668 // The no-wrapping add guarantees that the top bit will be set by the add.
669 // Therefore, the xor must be clearing the already set sign bit of Y.
670 if ((IsNSW
|| IsNUW
) && match(Op1
, m_SignMask()) &&
671 match(Op0
, m_Xor(m_Value(Y
), m_SignMask())))
674 // add nuw %x, -1 -> -1, because %x can only be 0.
675 if (IsNUW
&& match(Op1
, m_AllOnes()))
676 return Op1
; // Which is -1.
679 if (MaxRecurse
&& Op0
->getType()->isIntOrIntVectorTy(1))
680 if (Value
*V
= simplifyXorInst(Op0
, Op1
, Q
, MaxRecurse
- 1))
683 // Try some generic simplifications for associative operations.
685 simplifyAssociativeBinOp(Instruction::Add
, Op0
, Op1
, Q
, MaxRecurse
))
688 // Threading Add over selects and phi nodes is pointless, so don't bother.
689 // Threading over the select in "A + select(cond, B, C)" means evaluating
690 // "A+B" and "A+C" and seeing if they are equal; but they are equal if and
691 // only if B and C are equal. If B and C are equal then (since we assume
692 // that operands have already been simplified) "select(cond, B, C)" should
693 // have been simplified to the common value of B and C already. Analysing
694 // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
695 // for threading over phi nodes.
700 Value
*llvm::simplifyAddInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
701 const SimplifyQuery
&Query
) {
702 return ::simplifyAddInst(Op0
, Op1
, IsNSW
, IsNUW
, Query
, RecursionLimit
);
705 /// Compute the base pointer and cumulative constant offsets for V.
707 /// This strips all constant offsets off of V, leaving it the base pointer, and
708 /// accumulates the total constant offset applied in the returned constant.
709 /// It returns zero if there are no constant offsets applied.
711 /// This is very similar to stripAndAccumulateConstantOffsets(), except it
712 /// normalizes the offset bitwidth to the stripped pointer type, not the
713 /// original pointer type.
714 static APInt
stripAndComputeConstantOffsets(const DataLayout
&DL
, Value
*&V
,
715 bool AllowNonInbounds
= false) {
716 assert(V
->getType()->isPtrOrPtrVectorTy());
718 APInt Offset
= APInt::getZero(DL
.getIndexTypeSizeInBits(V
->getType()));
719 V
= V
->stripAndAccumulateConstantOffsets(DL
, Offset
, AllowNonInbounds
);
720 // As that strip may trace through `addrspacecast`, need to sext or trunc
721 // the offset calculated.
722 return Offset
.sextOrTrunc(DL
.getIndexTypeSizeInBits(V
->getType()));
725 /// Compute the constant difference between two pointer values.
726 /// If the difference is not a constant, returns zero.
727 static Constant
*computePointerDifference(const DataLayout
&DL
, Value
*LHS
,
729 APInt LHSOffset
= stripAndComputeConstantOffsets(DL
, LHS
);
730 APInt RHSOffset
= stripAndComputeConstantOffsets(DL
, RHS
);
732 // If LHS and RHS are not related via constant offsets to the same base
733 // value, there is nothing we can do here.
737 // Otherwise, the difference of LHS - RHS can be computed as:
739 // = (LHSOffset + Base) - (RHSOffset + Base)
740 // = LHSOffset - RHSOffset
741 Constant
*Res
= ConstantInt::get(LHS
->getContext(), LHSOffset
- RHSOffset
);
742 if (auto *VecTy
= dyn_cast
<VectorType
>(LHS
->getType()))
743 Res
= ConstantVector::getSplat(VecTy
->getElementCount(), Res
);
747 /// Test if there is a dominating equivalence condition for the
748 /// two operands. If there is, try to reduce the binary operation
749 /// between the two operands.
750 /// Example: Op0 - Op1 --> 0 when Op0 == Op1
751 static Value
*simplifyByDomEq(unsigned Opcode
, Value
*Op0
, Value
*Op1
,
752 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
753 // Recursive run it can not get any benefit
754 if (MaxRecurse
!= RecursionLimit
)
757 std::optional
<bool> Imp
=
758 isImpliedByDomCondition(CmpInst::ICMP_EQ
, Op0
, Op1
, Q
.CxtI
, Q
.DL
);
760 Type
*Ty
= Op0
->getType();
762 case Instruction::Sub
:
763 case Instruction::Xor
:
764 case Instruction::URem
:
765 case Instruction::SRem
:
766 return Constant::getNullValue(Ty
);
768 case Instruction::SDiv
:
769 case Instruction::UDiv
:
770 return ConstantInt::get(Ty
, 1);
772 case Instruction::And
:
773 case Instruction::Or
:
774 // Could be either one - choose Op1 since that's more likely a constant.
783 /// Given operands for a Sub, see if we can fold the result.
784 /// If not, this returns null.
785 static Value
*simplifySubInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
786 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
787 if (Constant
*C
= foldOrCommuteConstant(Instruction::Sub
, Op0
, Op1
, Q
))
790 // X - poison -> poison
791 // poison - X -> poison
792 if (isa
<PoisonValue
>(Op0
) || isa
<PoisonValue
>(Op1
))
793 return PoisonValue::get(Op0
->getType());
795 // X - undef -> undef
796 // undef - X -> undef
797 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
798 return UndefValue::get(Op0
->getType());
801 if (match(Op1
, m_Zero()))
806 return Constant::getNullValue(Op0
->getType());
808 // Is this a negation?
809 if (match(Op0
, m_Zero())) {
810 // 0 - X -> 0 if the sub is NUW.
812 return Constant::getNullValue(Op0
->getType());
814 KnownBits Known
= computeKnownBits(Op1
, /* Depth */ 0, Q
);
815 if (Known
.Zero
.isMaxSignedValue()) {
816 // Op1 is either 0 or the minimum signed value. If the sub is NSW, then
817 // Op1 must be 0 because negating the minimum signed value is undefined.
819 return Constant::getNullValue(Op0
->getType());
821 // 0 - X -> X if X is 0 or the minimum signed value.
826 // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
827 // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
828 Value
*X
= nullptr, *Y
= nullptr, *Z
= Op1
;
829 if (MaxRecurse
&& match(Op0
, m_Add(m_Value(X
), m_Value(Y
)))) { // (X + Y) - Z
830 // See if "V === Y - Z" simplifies.
831 if (Value
*V
= simplifyBinOp(Instruction::Sub
, Y
, Z
, Q
, MaxRecurse
- 1))
832 // It does! Now see if "X + V" simplifies.
833 if (Value
*W
= simplifyBinOp(Instruction::Add
, X
, V
, Q
, MaxRecurse
- 1)) {
834 // It does, we successfully reassociated!
838 // See if "V === X - Z" simplifies.
839 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Z
, Q
, MaxRecurse
- 1))
840 // It does! Now see if "Y + V" simplifies.
841 if (Value
*W
= simplifyBinOp(Instruction::Add
, Y
, V
, Q
, MaxRecurse
- 1)) {
842 // It does, we successfully reassociated!
848 // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
849 // For example, X - (X + 1) -> -1
851 if (MaxRecurse
&& match(Op1
, m_Add(m_Value(Y
), m_Value(Z
)))) { // X - (Y + Z)
852 // See if "V === X - Y" simplifies.
853 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Y
, Q
, MaxRecurse
- 1))
854 // It does! Now see if "V - Z" simplifies.
855 if (Value
*W
= simplifyBinOp(Instruction::Sub
, V
, Z
, Q
, MaxRecurse
- 1)) {
856 // It does, we successfully reassociated!
860 // See if "V === X - Z" simplifies.
861 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Z
, Q
, MaxRecurse
- 1))
862 // It does! Now see if "V - Y" simplifies.
863 if (Value
*W
= simplifyBinOp(Instruction::Sub
, V
, Y
, Q
, MaxRecurse
- 1)) {
864 // It does, we successfully reassociated!
870 // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
871 // For example, X - (X - Y) -> Y.
873 if (MaxRecurse
&& match(Op1
, m_Sub(m_Value(X
), m_Value(Y
)))) // Z - (X - Y)
874 // See if "V === Z - X" simplifies.
875 if (Value
*V
= simplifyBinOp(Instruction::Sub
, Z
, X
, Q
, MaxRecurse
- 1))
876 // It does! Now see if "V + Y" simplifies.
877 if (Value
*W
= simplifyBinOp(Instruction::Add
, V
, Y
, Q
, MaxRecurse
- 1)) {
878 // It does, we successfully reassociated!
883 // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
884 if (MaxRecurse
&& match(Op0
, m_Trunc(m_Value(X
))) &&
885 match(Op1
, m_Trunc(m_Value(Y
))))
886 if (X
->getType() == Y
->getType())
887 // See if "V === X - Y" simplifies.
888 if (Value
*V
= simplifyBinOp(Instruction::Sub
, X
, Y
, Q
, MaxRecurse
- 1))
889 // It does! Now see if "trunc V" simplifies.
890 if (Value
*W
= simplifyCastInst(Instruction::Trunc
, V
, Op0
->getType(),
892 // It does, return the simplified "trunc V".
895 // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
896 if (match(Op0
, m_PtrToInt(m_Value(X
))) && match(Op1
, m_PtrToInt(m_Value(Y
))))
897 if (Constant
*Result
= computePointerDifference(Q
.DL
, X
, Y
))
898 return ConstantFoldIntegerCast(Result
, Op0
->getType(), /*IsSigned*/ true,
902 if (MaxRecurse
&& Op0
->getType()->isIntOrIntVectorTy(1))
903 if (Value
*V
= simplifyXorInst(Op0
, Op1
, Q
, MaxRecurse
- 1))
906 // Threading Sub over selects and phi nodes is pointless, so don't bother.
907 // Threading over the select in "A - select(cond, B, C)" means evaluating
908 // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
909 // only if B and C are equal. If B and C are equal then (since we assume
910 // that operands have already been simplified) "select(cond, B, C)" should
911 // have been simplified to the common value of B and C already. Analysing
912 // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
913 // for threading over phi nodes.
915 if (Value
*V
= simplifyByDomEq(Instruction::Sub
, Op0
, Op1
, Q
, MaxRecurse
))
921 Value
*llvm::simplifySubInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
922 const SimplifyQuery
&Q
) {
923 return ::simplifySubInst(Op0
, Op1
, IsNSW
, IsNUW
, Q
, RecursionLimit
);
926 /// Given operands for a Mul, see if we can fold the result.
927 /// If not, this returns null.
928 static Value
*simplifyMulInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
929 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
930 if (Constant
*C
= foldOrCommuteConstant(Instruction::Mul
, Op0
, Op1
, Q
))
933 // X * poison -> poison
934 if (isa
<PoisonValue
>(Op1
))
939 if (Q
.isUndefValue(Op1
) || match(Op1
, m_Zero()))
940 return Constant::getNullValue(Op0
->getType());
943 if (match(Op1
, m_One()))
946 // (X / Y) * Y -> X if the division is exact.
948 if (Q
.IIQ
.UseInstrInfo
&&
950 m_Exact(m_IDiv(m_Value(X
), m_Specific(Op1
)))) || // (X / Y) * Y
951 match(Op1
, m_Exact(m_IDiv(m_Value(X
), m_Specific(Op0
)))))) // Y * (X / Y)
954 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
955 // mul i1 nsw is a special-case because -1 * -1 is poison (+1 is not
956 // representable). All other cases reduce to 0, so just return 0.
958 return ConstantInt::getNullValue(Op0
->getType());
960 // Treat "mul i1" as "and i1".
962 if (Value
*V
= simplifyAndInst(Op0
, Op1
, Q
, MaxRecurse
- 1))
966 // Try some generic simplifications for associative operations.
968 simplifyAssociativeBinOp(Instruction::Mul
, Op0
, Op1
, Q
, MaxRecurse
))
971 // Mul distributes over Add. Try some generic simplifications based on this.
972 if (Value
*V
= expandCommutativeBinOp(Instruction::Mul
, Op0
, Op1
,
973 Instruction::Add
, Q
, MaxRecurse
))
976 // If the operation is with the result of a select instruction, check whether
977 // operating on either branch of the select always yields the same value.
978 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
))
980 threadBinOpOverSelect(Instruction::Mul
, Op0
, Op1
, Q
, MaxRecurse
))
983 // If the operation is with the result of a phi instruction, check whether
984 // operating on all incoming values of the phi always yields the same value.
985 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
987 threadBinOpOverPHI(Instruction::Mul
, Op0
, Op1
, Q
, MaxRecurse
))
993 Value
*llvm::simplifyMulInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
994 const SimplifyQuery
&Q
) {
995 return ::simplifyMulInst(Op0
, Op1
, IsNSW
, IsNUW
, Q
, RecursionLimit
);
998 /// Given a predicate and two operands, return true if the comparison is true.
999 /// This is a helper for div/rem simplification where we return some other value
1000 /// when we can prove a relationship between the operands.
1001 static bool isICmpTrue(ICmpInst::Predicate Pred
, Value
*LHS
, Value
*RHS
,
1002 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1003 Value
*V
= simplifyICmpInst(Pred
, LHS
, RHS
, Q
, MaxRecurse
);
1004 Constant
*C
= dyn_cast_or_null
<Constant
>(V
);
1005 return (C
&& C
->isAllOnesValue());
1008 /// Return true if we can simplify X / Y to 0. Remainder can adapt that answer
1009 /// to simplify X % Y to X.
1010 static bool isDivZero(Value
*X
, Value
*Y
, const SimplifyQuery
&Q
,
1011 unsigned MaxRecurse
, bool IsSigned
) {
1012 // Recursion is always used, so bail out at once if we already hit the limit.
1017 // (X srem Y) sdiv Y --> 0
1018 if (match(X
, m_SRem(m_Value(), m_Specific(Y
))))
1023 // We require that 1 operand is a simple constant. That could be extended to
1024 // 2 variables if we computed the sign bit for each.
1026 // Make sure that a constant is not the minimum signed value because taking
1027 // the abs() of that is undefined.
1028 Type
*Ty
= X
->getType();
1030 if (match(X
, m_APInt(C
)) && !C
->isMinSignedValue()) {
1031 // Is the variable divisor magnitude always greater than the constant
1032 // dividend magnitude?
1033 // |Y| > |C| --> Y < -abs(C) or Y > abs(C)
1034 Constant
*PosDividendC
= ConstantInt::get(Ty
, C
->abs());
1035 Constant
*NegDividendC
= ConstantInt::get(Ty
, -C
->abs());
1036 if (isICmpTrue(CmpInst::ICMP_SLT
, Y
, NegDividendC
, Q
, MaxRecurse
) ||
1037 isICmpTrue(CmpInst::ICMP_SGT
, Y
, PosDividendC
, Q
, MaxRecurse
))
1040 if (match(Y
, m_APInt(C
))) {
1041 // Special-case: we can't take the abs() of a minimum signed value. If
1042 // that's the divisor, then all we have to do is prove that the dividend
1043 // is also not the minimum signed value.
1044 if (C
->isMinSignedValue())
1045 return isICmpTrue(CmpInst::ICMP_NE
, X
, Y
, Q
, MaxRecurse
);
1047 // Is the variable dividend magnitude always less than the constant
1048 // divisor magnitude?
1049 // |X| < |C| --> X > -abs(C) and X < abs(C)
1050 Constant
*PosDivisorC
= ConstantInt::get(Ty
, C
->abs());
1051 Constant
*NegDivisorC
= ConstantInt::get(Ty
, -C
->abs());
1052 if (isICmpTrue(CmpInst::ICMP_SGT
, X
, NegDivisorC
, Q
, MaxRecurse
) &&
1053 isICmpTrue(CmpInst::ICMP_SLT
, X
, PosDivisorC
, Q
, MaxRecurse
))
1059 // IsSigned == false.
1061 // Is the unsigned dividend known to be less than a constant divisor?
1062 // TODO: Convert this (and above) to range analysis
1063 // ("computeConstantRangeIncludingKnownBits")?
1065 if (match(Y
, m_APInt(C
)) &&
1066 computeKnownBits(X
, /* Depth */ 0, Q
).getMaxValue().ult(*C
))
1069 // Try again for any divisor:
1070 // Is the dividend unsigned less than the divisor?
1071 return isICmpTrue(ICmpInst::ICMP_ULT
, X
, Y
, Q
, MaxRecurse
);
1074 /// Check for common or similar folds of integer division or integer remainder.
1075 /// This applies to all 4 opcodes (sdiv/udiv/srem/urem).
1076 static Value
*simplifyDivRem(Instruction::BinaryOps Opcode
, Value
*Op0
,
1077 Value
*Op1
, const SimplifyQuery
&Q
,
1078 unsigned MaxRecurse
) {
1079 bool IsDiv
= (Opcode
== Instruction::SDiv
|| Opcode
== Instruction::UDiv
);
1080 bool IsSigned
= (Opcode
== Instruction::SDiv
|| Opcode
== Instruction::SRem
);
1082 Type
*Ty
= Op0
->getType();
1084 // X / undef -> poison
1085 // X % undef -> poison
1086 if (Q
.isUndefValue(Op1
) || isa
<PoisonValue
>(Op1
))
1087 return PoisonValue::get(Ty
);
1091 // We don't need to preserve faults!
1092 if (match(Op1
, m_Zero()))
1093 return PoisonValue::get(Ty
);
1095 // If any element of a constant divisor fixed width vector is zero or undef
1096 // the behavior is undefined and we can fold the whole op to poison.
1097 auto *Op1C
= dyn_cast
<Constant
>(Op1
);
1098 auto *VTy
= dyn_cast
<FixedVectorType
>(Ty
);
1100 unsigned NumElts
= VTy
->getNumElements();
1101 for (unsigned i
= 0; i
!= NumElts
; ++i
) {
1102 Constant
*Elt
= Op1C
->getAggregateElement(i
);
1103 if (Elt
&& (Elt
->isNullValue() || Q
.isUndefValue(Elt
)))
1104 return PoisonValue::get(Ty
);
1108 // poison / X -> poison
1109 // poison % X -> poison
1110 if (isa
<PoisonValue
>(Op0
))
1115 if (Q
.isUndefValue(Op0
))
1116 return Constant::getNullValue(Ty
);
1120 if (match(Op0
, m_Zero()))
1121 return Constant::getNullValue(Op0
->getType());
1126 return IsDiv
? ConstantInt::get(Ty
, 1) : Constant::getNullValue(Ty
);
1128 KnownBits Known
= computeKnownBits(Op1
, /* Depth */ 0, Q
);
1131 // If the divisor is known to be zero, just return poison. This can happen in
1132 // some cases where its provable indirectly the denominator is zero but it's
1133 // not trivially simplifiable (i.e known zero through a phi node).
1135 return PoisonValue::get(Ty
);
1139 // If the divisor can only be zero or one, we can't have division-by-zero
1140 // or remainder-by-zero, so assume the divisor is 1.
1141 // e.g. 1, zext (i8 X), sdiv X (Y and 1)
1142 if (Known
.countMinLeadingZeros() == Known
.getBitWidth() - 1)
1143 return IsDiv
? Op0
: Constant::getNullValue(Ty
);
1145 // If X * Y does not overflow, then:
1149 if (match(Op0
, m_c_Mul(m_Value(X
), m_Specific(Op1
)))) {
1150 auto *Mul
= cast
<OverflowingBinaryOperator
>(Op0
);
1151 // The multiplication can't overflow if it is defined not to, or if
1152 // X == A / Y for some A.
1153 if ((IsSigned
&& Q
.IIQ
.hasNoSignedWrap(Mul
)) ||
1154 (!IsSigned
&& Q
.IIQ
.hasNoUnsignedWrap(Mul
)) ||
1155 (IsSigned
&& match(X
, m_SDiv(m_Value(), m_Specific(Op1
)))) ||
1156 (!IsSigned
&& match(X
, m_UDiv(m_Value(), m_Specific(Op1
))))) {
1157 return IsDiv
? X
: Constant::getNullValue(Op0
->getType());
1161 if (isDivZero(Op0
, Op1
, Q
, MaxRecurse
, IsSigned
))
1162 return IsDiv
? Constant::getNullValue(Op0
->getType()) : Op0
;
1164 if (Value
*V
= simplifyByDomEq(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1167 // If the operation is with the result of a select instruction, check whether
1168 // operating on either branch of the select always yields the same value.
1169 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
))
1170 if (Value
*V
= threadBinOpOverSelect(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1173 // If the operation is with the result of a phi instruction, check whether
1174 // operating on all incoming values of the phi always yields the same value.
1175 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
1176 if (Value
*V
= threadBinOpOverPHI(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1182 /// These are simplifications common to SDiv and UDiv.
1183 static Value
*simplifyDiv(Instruction::BinaryOps Opcode
, Value
*Op0
, Value
*Op1
,
1184 bool IsExact
, const SimplifyQuery
&Q
,
1185 unsigned MaxRecurse
) {
1186 if (Constant
*C
= foldOrCommuteConstant(Opcode
, Op0
, Op1
, Q
))
1189 if (Value
*V
= simplifyDivRem(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1193 if (IsExact
&& match(Op1
, m_APInt(DivC
))) {
1194 // If this is an exact divide by a constant, then the dividend (Op0) must
1195 // have at least as many trailing zeros as the divisor to divide evenly. If
1196 // it has less trailing zeros, then the result must be poison.
1197 if (DivC
->countr_zero()) {
1198 KnownBits KnownOp0
= computeKnownBits(Op0
, /* Depth */ 0, Q
);
1199 if (KnownOp0
.countMaxTrailingZeros() < DivC
->countr_zero())
1200 return PoisonValue::get(Op0
->getType());
1203 // udiv exact (mul nsw X, C), C --> X
1204 // sdiv exact (mul nuw X, C), C --> X
1205 // where C is not a power of 2.
1207 if (!DivC
->isPowerOf2() &&
1208 (Opcode
== Instruction::UDiv
1209 ? match(Op0
, m_NSWMul(m_Value(X
), m_Specific(Op1
)))
1210 : match(Op0
, m_NUWMul(m_Value(X
), m_Specific(Op1
)))))
1217 /// These are simplifications common to SRem and URem.
1218 static Value
*simplifyRem(Instruction::BinaryOps Opcode
, Value
*Op0
, Value
*Op1
,
1219 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1220 if (Constant
*C
= foldOrCommuteConstant(Opcode
, Op0
, Op1
, Q
))
1223 if (Value
*V
= simplifyDivRem(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1226 // (X << Y) % X -> 0
1227 if (Q
.IIQ
.UseInstrInfo
&&
1228 ((Opcode
== Instruction::SRem
&&
1229 match(Op0
, m_NSWShl(m_Specific(Op1
), m_Value()))) ||
1230 (Opcode
== Instruction::URem
&&
1231 match(Op0
, m_NUWShl(m_Specific(Op1
), m_Value())))))
1232 return Constant::getNullValue(Op0
->getType());
1237 /// Given operands for an SDiv, see if we can fold the result.
1238 /// If not, this returns null.
1239 static Value
*simplifySDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1240 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1241 // If two operands are negated and no signed overflow, return -1.
1242 if (isKnownNegation(Op0
, Op1
, /*NeedNSW=*/true))
1243 return Constant::getAllOnesValue(Op0
->getType());
1245 return simplifyDiv(Instruction::SDiv
, Op0
, Op1
, IsExact
, Q
, MaxRecurse
);
1248 Value
*llvm::simplifySDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1249 const SimplifyQuery
&Q
) {
1250 return ::simplifySDivInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1253 /// Given operands for a UDiv, see if we can fold the result.
1254 /// If not, this returns null.
1255 static Value
*simplifyUDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1256 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1257 return simplifyDiv(Instruction::UDiv
, Op0
, Op1
, IsExact
, Q
, MaxRecurse
);
1260 Value
*llvm::simplifyUDivInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1261 const SimplifyQuery
&Q
) {
1262 return ::simplifyUDivInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1265 /// Given operands for an SRem, see if we can fold the result.
1266 /// If not, this returns null.
1267 static Value
*simplifySRemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
1268 unsigned MaxRecurse
) {
1269 // If the divisor is 0, the result is undefined, so assume the divisor is -1.
1270 // srem Op0, (sext i1 X) --> srem Op0, -1 --> 0
1272 if (match(Op1
, m_SExt(m_Value(X
))) && X
->getType()->isIntOrIntVectorTy(1))
1273 return ConstantInt::getNullValue(Op0
->getType());
1275 // If the two operands are negated, return 0.
1276 if (isKnownNegation(Op0
, Op1
))
1277 return ConstantInt::getNullValue(Op0
->getType());
1279 return simplifyRem(Instruction::SRem
, Op0
, Op1
, Q
, MaxRecurse
);
1282 Value
*llvm::simplifySRemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
1283 return ::simplifySRemInst(Op0
, Op1
, Q
, RecursionLimit
);
1286 /// Given operands for a URem, see if we can fold the result.
1287 /// If not, this returns null.
1288 static Value
*simplifyURemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
1289 unsigned MaxRecurse
) {
1290 return simplifyRem(Instruction::URem
, Op0
, Op1
, Q
, MaxRecurse
);
1293 Value
*llvm::simplifyURemInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
1294 return ::simplifyURemInst(Op0
, Op1
, Q
, RecursionLimit
);
1297 /// Returns true if a shift by \c Amount always yields poison.
1298 static bool isPoisonShift(Value
*Amount
, const SimplifyQuery
&Q
) {
1299 Constant
*C
= dyn_cast
<Constant
>(Amount
);
1303 // X shift by undef -> poison because it may shift by the bitwidth.
1304 if (Q
.isUndefValue(C
))
1307 // Shifting by the bitwidth or more is poison. This covers scalars and
1308 // fixed/scalable vectors with splat constants.
1309 const APInt
*AmountC
;
1310 if (match(C
, m_APInt(AmountC
)) && AmountC
->uge(AmountC
->getBitWidth()))
1313 // Try harder for fixed-length vectors:
1314 // If all lanes of a vector shift are poison, the whole shift is poison.
1315 if (isa
<ConstantVector
>(C
) || isa
<ConstantDataVector
>(C
)) {
1316 for (unsigned I
= 0,
1317 E
= cast
<FixedVectorType
>(C
->getType())->getNumElements();
1319 if (!isPoisonShift(C
->getAggregateElement(I
), Q
))
1327 /// Given operands for an Shl, LShr or AShr, see if we can fold the result.
1328 /// If not, this returns null.
1329 static Value
*simplifyShift(Instruction::BinaryOps Opcode
, Value
*Op0
,
1330 Value
*Op1
, bool IsNSW
, const SimplifyQuery
&Q
,
1331 unsigned MaxRecurse
) {
1332 if (Constant
*C
= foldOrCommuteConstant(Opcode
, Op0
, Op1
, Q
))
1335 // poison shift by X -> poison
1336 if (isa
<PoisonValue
>(Op0
))
1339 // 0 shift by X -> 0
1340 if (match(Op0
, m_Zero()))
1341 return Constant::getNullValue(Op0
->getType());
1343 // X shift by 0 -> X
1344 // Shift-by-sign-extended bool must be shift-by-0 because shift-by-all-ones
1347 if (match(Op1
, m_Zero()) ||
1348 (match(Op1
, m_SExt(m_Value(X
))) && X
->getType()->isIntOrIntVectorTy(1)))
1351 // Fold undefined shifts.
1352 if (isPoisonShift(Op1
, Q
))
1353 return PoisonValue::get(Op0
->getType());
1355 // If the operation is with the result of a select instruction, check whether
1356 // operating on either branch of the select always yields the same value.
1357 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
))
1358 if (Value
*V
= threadBinOpOverSelect(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1361 // If the operation is with the result of a phi instruction, check whether
1362 // operating on all incoming values of the phi always yields the same value.
1363 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
1364 if (Value
*V
= threadBinOpOverPHI(Opcode
, Op0
, Op1
, Q
, MaxRecurse
))
1367 // If any bits in the shift amount make that value greater than or equal to
1368 // the number of bits in the type, the shift is undefined.
1369 KnownBits KnownAmt
= computeKnownBits(Op1
, /* Depth */ 0, Q
);
1370 if (KnownAmt
.getMinValue().uge(KnownAmt
.getBitWidth()))
1371 return PoisonValue::get(Op0
->getType());
1373 // If all valid bits in the shift amount are known zero, the first operand is
1375 unsigned NumValidShiftBits
= Log2_32_Ceil(KnownAmt
.getBitWidth());
1376 if (KnownAmt
.countMinTrailingZeros() >= NumValidShiftBits
)
1379 // Check for nsw shl leading to a poison value.
1381 assert(Opcode
== Instruction::Shl
&& "Expected shl for nsw instruction");
1382 KnownBits KnownVal
= computeKnownBits(Op0
, /* Depth */ 0, Q
);
1383 KnownBits KnownShl
= KnownBits::shl(KnownVal
, KnownAmt
);
1385 if (KnownVal
.Zero
.isSignBitSet())
1386 KnownShl
.Zero
.setSignBit();
1387 if (KnownVal
.One
.isSignBitSet())
1388 KnownShl
.One
.setSignBit();
1390 if (KnownShl
.hasConflict())
1391 return PoisonValue::get(Op0
->getType());
1397 /// Given operands for an LShr or AShr, see if we can fold the result. If not,
1398 /// this returns null.
1399 static Value
*simplifyRightShift(Instruction::BinaryOps Opcode
, Value
*Op0
,
1400 Value
*Op1
, bool IsExact
,
1401 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1403 simplifyShift(Opcode
, Op0
, Op1
, /*IsNSW*/ false, Q
, MaxRecurse
))
1408 return Constant::getNullValue(Op0
->getType());
1411 // undef >> X -> undef (if it's exact)
1412 if (Q
.isUndefValue(Op0
))
1413 return IsExact
? Op0
: Constant::getNullValue(Op0
->getType());
1415 // The low bit cannot be shifted out of an exact shift if it is set.
1416 // TODO: Generalize by counting trailing zeros (see fold for exact division).
1418 KnownBits Op0Known
= computeKnownBits(Op0
, /* Depth */ 0, Q
);
1419 if (Op0Known
.One
[0])
1426 /// Given operands for an Shl, see if we can fold the result.
1427 /// If not, this returns null.
1428 static Value
*simplifyShlInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
1429 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1431 simplifyShift(Instruction::Shl
, Op0
, Op1
, IsNSW
, Q
, MaxRecurse
))
1434 Type
*Ty
= Op0
->getType();
1436 // undef << X -> undef if (if it's NSW/NUW)
1437 if (Q
.isUndefValue(Op0
))
1438 return IsNSW
|| IsNUW
? Op0
: Constant::getNullValue(Ty
);
1440 // (X >> A) << A -> X
1442 if (Q
.IIQ
.UseInstrInfo
&&
1443 match(Op0
, m_Exact(m_Shr(m_Value(X
), m_Specific(Op1
)))))
1446 // shl nuw i8 C, %x -> C iff C has sign bit set.
1447 if (IsNUW
&& match(Op0
, m_Negative()))
1449 // NOTE: could use computeKnownBits() / LazyValueInfo,
1450 // but the cost-benefit analysis suggests it isn't worth it.
1452 // "nuw" guarantees that only zeros are shifted out, and "nsw" guarantees
1453 // that the sign-bit does not change, so the only input that does not
1454 // produce poison is 0, and "0 << (bitwidth-1) --> 0".
1455 if (IsNSW
&& IsNUW
&&
1456 match(Op1
, m_SpecificInt(Ty
->getScalarSizeInBits() - 1)))
1457 return Constant::getNullValue(Ty
);
1462 Value
*llvm::simplifyShlInst(Value
*Op0
, Value
*Op1
, bool IsNSW
, bool IsNUW
,
1463 const SimplifyQuery
&Q
) {
1464 return ::simplifyShlInst(Op0
, Op1
, IsNSW
, IsNUW
, Q
, RecursionLimit
);
1467 /// Given operands for an LShr, see if we can fold the result.
1468 /// If not, this returns null.
1469 static Value
*simplifyLShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1470 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1471 if (Value
*V
= simplifyRightShift(Instruction::LShr
, Op0
, Op1
, IsExact
, Q
,
1475 // (X << A) >> A -> X
1477 if (Q
.IIQ
.UseInstrInfo
&& match(Op0
, m_NUWShl(m_Value(X
), m_Specific(Op1
))))
1480 // ((X << A) | Y) >> A -> X if effective width of Y is not larger than A.
1481 // We can return X as we do in the above case since OR alters no bits in X.
1482 // SimplifyDemandedBits in InstCombine can do more general optimization for
1483 // bit manipulation. This pattern aims to provide opportunities for other
1484 // optimizers by supporting a simple but common case in InstSimplify.
1486 const APInt
*ShRAmt
, *ShLAmt
;
1487 if (Q
.IIQ
.UseInstrInfo
&& match(Op1
, m_APInt(ShRAmt
)) &&
1488 match(Op0
, m_c_Or(m_NUWShl(m_Value(X
), m_APInt(ShLAmt
)), m_Value(Y
))) &&
1489 *ShRAmt
== *ShLAmt
) {
1490 const KnownBits YKnown
= computeKnownBits(Y
, /* Depth */ 0, Q
);
1491 const unsigned EffWidthY
= YKnown
.countMaxActiveBits();
1492 if (ShRAmt
->uge(EffWidthY
))
1499 Value
*llvm::simplifyLShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1500 const SimplifyQuery
&Q
) {
1501 return ::simplifyLShrInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1504 /// Given operands for an AShr, see if we can fold the result.
1505 /// If not, this returns null.
1506 static Value
*simplifyAShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1507 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
1508 if (Value
*V
= simplifyRightShift(Instruction::AShr
, Op0
, Op1
, IsExact
, Q
,
1513 // (-1 << X) a>> X --> -1
1514 // Do not return Op0 because it may contain undef elements if it's a vector.
1515 if (match(Op0
, m_AllOnes()) ||
1516 match(Op0
, m_Shl(m_AllOnes(), m_Specific(Op1
))))
1517 return Constant::getAllOnesValue(Op0
->getType());
1519 // (X << A) >> A -> X
1521 if (Q
.IIQ
.UseInstrInfo
&& match(Op0
, m_NSWShl(m_Value(X
), m_Specific(Op1
))))
1524 // Arithmetic shifting an all-sign-bit value is a no-op.
1525 unsigned NumSignBits
= ComputeNumSignBits(Op0
, Q
.DL
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
);
1526 if (NumSignBits
== Op0
->getType()->getScalarSizeInBits())
1532 Value
*llvm::simplifyAShrInst(Value
*Op0
, Value
*Op1
, bool IsExact
,
1533 const SimplifyQuery
&Q
) {
1534 return ::simplifyAShrInst(Op0
, Op1
, IsExact
, Q
, RecursionLimit
);
1537 /// Commuted variants are assumed to be handled by calling this function again
1538 /// with the parameters swapped.
1539 static Value
*simplifyUnsignedRangeCheck(ICmpInst
*ZeroICmp
,
1540 ICmpInst
*UnsignedICmp
, bool IsAnd
,
1541 const SimplifyQuery
&Q
) {
1544 ICmpInst::Predicate EqPred
;
1545 if (!match(ZeroICmp
, m_ICmp(EqPred
, m_Value(Y
), m_Zero())) ||
1546 !ICmpInst::isEquality(EqPred
))
1549 ICmpInst::Predicate UnsignedPred
;
1553 if (match(Y
, m_Sub(m_Value(A
), m_Value(B
)))) {
1554 if (match(UnsignedICmp
,
1555 m_c_ICmp(UnsignedPred
, m_Specific(A
), m_Specific(B
))) &&
1556 ICmpInst::isUnsigned(UnsignedPred
)) {
1557 // A >=/<= B || (A - B) != 0 <--> true
1558 if ((UnsignedPred
== ICmpInst::ICMP_UGE
||
1559 UnsignedPred
== ICmpInst::ICMP_ULE
) &&
1560 EqPred
== ICmpInst::ICMP_NE
&& !IsAnd
)
1561 return ConstantInt::getTrue(UnsignedICmp
->getType());
1562 // A </> B && (A - B) == 0 <--> false
1563 if ((UnsignedPred
== ICmpInst::ICMP_ULT
||
1564 UnsignedPred
== ICmpInst::ICMP_UGT
) &&
1565 EqPred
== ICmpInst::ICMP_EQ
&& IsAnd
)
1566 return ConstantInt::getFalse(UnsignedICmp
->getType());
1568 // A </> B && (A - B) != 0 <--> A </> B
1569 // A </> B || (A - B) != 0 <--> (A - B) != 0
1570 if (EqPred
== ICmpInst::ICMP_NE
&& (UnsignedPred
== ICmpInst::ICMP_ULT
||
1571 UnsignedPred
== ICmpInst::ICMP_UGT
))
1572 return IsAnd
? UnsignedICmp
: ZeroICmp
;
1574 // A <=/>= B && (A - B) == 0 <--> (A - B) == 0
1575 // A <=/>= B || (A - B) == 0 <--> A <=/>= B
1576 if (EqPred
== ICmpInst::ICMP_EQ
&& (UnsignedPred
== ICmpInst::ICMP_ULE
||
1577 UnsignedPred
== ICmpInst::ICMP_UGE
))
1578 return IsAnd
? ZeroICmp
: UnsignedICmp
;
1581 // Given Y = (A - B)
1582 // Y >= A && Y != 0 --> Y >= A iff B != 0
1583 // Y < A || Y == 0 --> Y < A iff B != 0
1584 if (match(UnsignedICmp
,
1585 m_c_ICmp(UnsignedPred
, m_Specific(Y
), m_Specific(A
)))) {
1586 if (UnsignedPred
== ICmpInst::ICMP_UGE
&& IsAnd
&&
1587 EqPred
== ICmpInst::ICMP_NE
&&
1588 isKnownNonZero(B
, Q
.DL
, /*Depth=*/0, Q
.AC
, Q
.CxtI
, Q
.DT
))
1589 return UnsignedICmp
;
1590 if (UnsignedPred
== ICmpInst::ICMP_ULT
&& !IsAnd
&&
1591 EqPred
== ICmpInst::ICMP_EQ
&&
1592 isKnownNonZero(B
, Q
.DL
, /*Depth=*/0, Q
.AC
, Q
.CxtI
, Q
.DT
))
1593 return UnsignedICmp
;
1597 if (match(UnsignedICmp
, m_ICmp(UnsignedPred
, m_Value(X
), m_Specific(Y
))) &&
1598 ICmpInst::isUnsigned(UnsignedPred
))
1600 else if (match(UnsignedICmp
,
1601 m_ICmp(UnsignedPred
, m_Specific(Y
), m_Value(X
))) &&
1602 ICmpInst::isUnsigned(UnsignedPred
))
1603 UnsignedPred
= ICmpInst::getSwappedPredicate(UnsignedPred
);
1607 // X > Y && Y == 0 --> Y == 0 iff X != 0
1608 // X > Y || Y == 0 --> X > Y iff X != 0
1609 if (UnsignedPred
== ICmpInst::ICMP_UGT
&& EqPred
== ICmpInst::ICMP_EQ
&&
1610 isKnownNonZero(X
, Q
.DL
, /*Depth=*/0, Q
.AC
, Q
.CxtI
, Q
.DT
))
1611 return IsAnd
? ZeroICmp
: UnsignedICmp
;
1613 // X <= Y && Y != 0 --> X <= Y iff X != 0
1614 // X <= Y || Y != 0 --> Y != 0 iff X != 0
1615 if (UnsignedPred
== ICmpInst::ICMP_ULE
&& EqPred
== ICmpInst::ICMP_NE
&&
1616 isKnownNonZero(X
, Q
.DL
, /*Depth=*/0, Q
.AC
, Q
.CxtI
, Q
.DT
))
1617 return IsAnd
? UnsignedICmp
: ZeroICmp
;
1619 // The transforms below here are expected to be handled more generally with
1620 // simplifyAndOrOfICmpsWithLimitConst() or in InstCombine's
1621 // foldAndOrOfICmpsWithConstEq(). If we are looking to trim optimizer overlap,
1622 // these are candidates for removal.
1624 // X < Y && Y != 0 --> X < Y
1625 // X < Y || Y != 0 --> Y != 0
1626 if (UnsignedPred
== ICmpInst::ICMP_ULT
&& EqPred
== ICmpInst::ICMP_NE
)
1627 return IsAnd
? UnsignedICmp
: ZeroICmp
;
1629 // X >= Y && Y == 0 --> Y == 0
1630 // X >= Y || Y == 0 --> X >= Y
1631 if (UnsignedPred
== ICmpInst::ICMP_UGE
&& EqPred
== ICmpInst::ICMP_EQ
)
1632 return IsAnd
? ZeroICmp
: UnsignedICmp
;
1634 // X < Y && Y == 0 --> false
1635 if (UnsignedPred
== ICmpInst::ICMP_ULT
&& EqPred
== ICmpInst::ICMP_EQ
&&
1637 return getFalse(UnsignedICmp
->getType());
1639 // X >= Y || Y != 0 --> true
1640 if (UnsignedPred
== ICmpInst::ICMP_UGE
&& EqPred
== ICmpInst::ICMP_NE
&&
1642 return getTrue(UnsignedICmp
->getType());
1647 /// Test if a pair of compares with a shared operand and 2 constants has an
1648 /// empty set intersection, full set union, or if one compare is a superset of
1650 static Value
*simplifyAndOrOfICmpsWithConstants(ICmpInst
*Cmp0
, ICmpInst
*Cmp1
,
1652 // Look for this pattern: {and/or} (icmp X, C0), (icmp X, C1)).
1653 if (Cmp0
->getOperand(0) != Cmp1
->getOperand(0))
1656 const APInt
*C0
, *C1
;
1657 if (!match(Cmp0
->getOperand(1), m_APInt(C0
)) ||
1658 !match(Cmp1
->getOperand(1), m_APInt(C1
)))
1661 auto Range0
= ConstantRange::makeExactICmpRegion(Cmp0
->getPredicate(), *C0
);
1662 auto Range1
= ConstantRange::makeExactICmpRegion(Cmp1
->getPredicate(), *C1
);
1664 // For and-of-compares, check if the intersection is empty:
1665 // (icmp X, C0) && (icmp X, C1) --> empty set --> false
1666 if (IsAnd
&& Range0
.intersectWith(Range1
).isEmptySet())
1667 return getFalse(Cmp0
->getType());
1669 // For or-of-compares, check if the union is full:
1670 // (icmp X, C0) || (icmp X, C1) --> full set --> true
1671 if (!IsAnd
&& Range0
.unionWith(Range1
).isFullSet())
1672 return getTrue(Cmp0
->getType());
1674 // Is one range a superset of the other?
1675 // If this is and-of-compares, take the smaller set:
1676 // (icmp sgt X, 4) && (icmp sgt X, 42) --> icmp sgt X, 42
1677 // If this is or-of-compares, take the larger set:
1678 // (icmp sgt X, 4) || (icmp sgt X, 42) --> icmp sgt X, 4
1679 if (Range0
.contains(Range1
))
1680 return IsAnd
? Cmp1
: Cmp0
;
1681 if (Range1
.contains(Range0
))
1682 return IsAnd
? Cmp0
: Cmp1
;
1687 static Value
*simplifyAndOfICmpsWithAdd(ICmpInst
*Op0
, ICmpInst
*Op1
,
1688 const InstrInfoQuery
&IIQ
) {
1689 // (icmp (add V, C0), C1) & (icmp V, C0)
1690 ICmpInst::Predicate Pred0
, Pred1
;
1691 const APInt
*C0
, *C1
;
1693 if (!match(Op0
, m_ICmp(Pred0
, m_Add(m_Value(V
), m_APInt(C0
)), m_APInt(C1
))))
1696 if (!match(Op1
, m_ICmp(Pred1
, m_Specific(V
), m_Value())))
1699 auto *AddInst
= cast
<OverflowingBinaryOperator
>(Op0
->getOperand(0));
1700 if (AddInst
->getOperand(1) != Op1
->getOperand(1))
1703 Type
*ITy
= Op0
->getType();
1704 bool IsNSW
= IIQ
.hasNoSignedWrap(AddInst
);
1705 bool IsNUW
= IIQ
.hasNoUnsignedWrap(AddInst
);
1707 const APInt Delta
= *C1
- *C0
;
1708 if (C0
->isStrictlyPositive()) {
1710 if (Pred0
== ICmpInst::ICMP_ULT
&& Pred1
== ICmpInst::ICMP_SGT
)
1711 return getFalse(ITy
);
1712 if (Pred0
== ICmpInst::ICMP_SLT
&& Pred1
== ICmpInst::ICMP_SGT
&& IsNSW
)
1713 return getFalse(ITy
);
1716 if (Pred0
== ICmpInst::ICMP_ULE
&& Pred1
== ICmpInst::ICMP_SGT
)
1717 return getFalse(ITy
);
1718 if (Pred0
== ICmpInst::ICMP_SLE
&& Pred1
== ICmpInst::ICMP_SGT
&& IsNSW
)
1719 return getFalse(ITy
);
1722 if (C0
->getBoolValue() && IsNUW
) {
1724 if (Pred0
== ICmpInst::ICMP_ULT
&& Pred1
== ICmpInst::ICMP_UGT
)
1725 return getFalse(ITy
);
1727 if (Pred0
== ICmpInst::ICMP_ULE
&& Pred1
== ICmpInst::ICMP_UGT
)
1728 return getFalse(ITy
);
1734 /// Try to simplify and/or of icmp with ctpop intrinsic.
1735 static Value
*simplifyAndOrOfICmpsWithCtpop(ICmpInst
*Cmp0
, ICmpInst
*Cmp1
,
1737 ICmpInst::Predicate Pred0
, Pred1
;
1740 if (!match(Cmp0
, m_ICmp(Pred0
, m_Intrinsic
<Intrinsic::ctpop
>(m_Value(X
)),
1742 !match(Cmp1
, m_ICmp(Pred1
, m_Specific(X
), m_ZeroInt())) || C
->isZero())
1745 // (ctpop(X) == C) || (X != 0) --> X != 0 where C > 0
1746 if (!IsAnd
&& Pred0
== ICmpInst::ICMP_EQ
&& Pred1
== ICmpInst::ICMP_NE
)
1748 // (ctpop(X) != C) && (X == 0) --> X == 0 where C > 0
1749 if (IsAnd
&& Pred0
== ICmpInst::ICMP_NE
&& Pred1
== ICmpInst::ICMP_EQ
)
1755 static Value
*simplifyAndOfICmps(ICmpInst
*Op0
, ICmpInst
*Op1
,
1756 const SimplifyQuery
&Q
) {
1757 if (Value
*X
= simplifyUnsignedRangeCheck(Op0
, Op1
, /*IsAnd=*/true, Q
))
1759 if (Value
*X
= simplifyUnsignedRangeCheck(Op1
, Op0
, /*IsAnd=*/true, Q
))
1762 if (Value
*X
= simplifyAndOrOfICmpsWithConstants(Op0
, Op1
, true))
1765 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op0
, Op1
, true))
1767 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op1
, Op0
, true))
1770 if (Value
*X
= simplifyAndOfICmpsWithAdd(Op0
, Op1
, Q
.IIQ
))
1772 if (Value
*X
= simplifyAndOfICmpsWithAdd(Op1
, Op0
, Q
.IIQ
))
1778 static Value
*simplifyOrOfICmpsWithAdd(ICmpInst
*Op0
, ICmpInst
*Op1
,
1779 const InstrInfoQuery
&IIQ
) {
1780 // (icmp (add V, C0), C1) | (icmp V, C0)
1781 ICmpInst::Predicate Pred0
, Pred1
;
1782 const APInt
*C0
, *C1
;
1784 if (!match(Op0
, m_ICmp(Pred0
, m_Add(m_Value(V
), m_APInt(C0
)), m_APInt(C1
))))
1787 if (!match(Op1
, m_ICmp(Pred1
, m_Specific(V
), m_Value())))
1790 auto *AddInst
= cast
<BinaryOperator
>(Op0
->getOperand(0));
1791 if (AddInst
->getOperand(1) != Op1
->getOperand(1))
1794 Type
*ITy
= Op0
->getType();
1795 bool IsNSW
= IIQ
.hasNoSignedWrap(AddInst
);
1796 bool IsNUW
= IIQ
.hasNoUnsignedWrap(AddInst
);
1798 const APInt Delta
= *C1
- *C0
;
1799 if (C0
->isStrictlyPositive()) {
1801 if (Pred0
== ICmpInst::ICMP_UGE
&& Pred1
== ICmpInst::ICMP_SLE
)
1802 return getTrue(ITy
);
1803 if (Pred0
== ICmpInst::ICMP_SGE
&& Pred1
== ICmpInst::ICMP_SLE
&& IsNSW
)
1804 return getTrue(ITy
);
1807 if (Pred0
== ICmpInst::ICMP_UGT
&& Pred1
== ICmpInst::ICMP_SLE
)
1808 return getTrue(ITy
);
1809 if (Pred0
== ICmpInst::ICMP_SGT
&& Pred1
== ICmpInst::ICMP_SLE
&& IsNSW
)
1810 return getTrue(ITy
);
1813 if (C0
->getBoolValue() && IsNUW
) {
1815 if (Pred0
== ICmpInst::ICMP_UGE
&& Pred1
== ICmpInst::ICMP_ULE
)
1816 return getTrue(ITy
);
1818 if (Pred0
== ICmpInst::ICMP_UGT
&& Pred1
== ICmpInst::ICMP_ULE
)
1819 return getTrue(ITy
);
1825 static Value
*simplifyOrOfICmps(ICmpInst
*Op0
, ICmpInst
*Op1
,
1826 const SimplifyQuery
&Q
) {
1827 if (Value
*X
= simplifyUnsignedRangeCheck(Op0
, Op1
, /*IsAnd=*/false, Q
))
1829 if (Value
*X
= simplifyUnsignedRangeCheck(Op1
, Op0
, /*IsAnd=*/false, Q
))
1832 if (Value
*X
= simplifyAndOrOfICmpsWithConstants(Op0
, Op1
, false))
1835 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op0
, Op1
, false))
1837 if (Value
*X
= simplifyAndOrOfICmpsWithCtpop(Op1
, Op0
, false))
1840 if (Value
*X
= simplifyOrOfICmpsWithAdd(Op0
, Op1
, Q
.IIQ
))
1842 if (Value
*X
= simplifyOrOfICmpsWithAdd(Op1
, Op0
, Q
.IIQ
))
1848 static Value
*simplifyAndOrOfFCmps(const SimplifyQuery
&Q
, FCmpInst
*LHS
,
1849 FCmpInst
*RHS
, bool IsAnd
) {
1850 Value
*LHS0
= LHS
->getOperand(0), *LHS1
= LHS
->getOperand(1);
1851 Value
*RHS0
= RHS
->getOperand(0), *RHS1
= RHS
->getOperand(1);
1852 if (LHS0
->getType() != RHS0
->getType())
1855 const DataLayout
&DL
= Q
.DL
;
1856 const TargetLibraryInfo
*TLI
= Q
.TLI
;
1858 FCmpInst::Predicate PredL
= LHS
->getPredicate(), PredR
= RHS
->getPredicate();
1859 if ((PredL
== FCmpInst::FCMP_ORD
&& PredR
== FCmpInst::FCMP_ORD
&& IsAnd
) ||
1860 (PredL
== FCmpInst::FCMP_UNO
&& PredR
== FCmpInst::FCMP_UNO
&& !IsAnd
)) {
1861 // (fcmp ord NNAN, X) & (fcmp ord X, Y) --> fcmp ord X, Y
1862 // (fcmp ord NNAN, X) & (fcmp ord Y, X) --> fcmp ord Y, X
1863 // (fcmp ord X, NNAN) & (fcmp ord X, Y) --> fcmp ord X, Y
1864 // (fcmp ord X, NNAN) & (fcmp ord Y, X) --> fcmp ord Y, X
1865 // (fcmp uno NNAN, X) | (fcmp uno X, Y) --> fcmp uno X, Y
1866 // (fcmp uno NNAN, X) | (fcmp uno Y, X) --> fcmp uno Y, X
1867 // (fcmp uno X, NNAN) | (fcmp uno X, Y) --> fcmp uno X, Y
1868 // (fcmp uno X, NNAN) | (fcmp uno Y, X) --> fcmp uno Y, X
1869 if (((LHS1
== RHS0
|| LHS1
== RHS1
) &&
1870 isKnownNeverNaN(LHS0
, DL
, TLI
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
)) ||
1871 ((LHS0
== RHS0
|| LHS0
== RHS1
) &&
1872 isKnownNeverNaN(LHS1
, DL
, TLI
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
)))
1875 // (fcmp ord X, Y) & (fcmp ord NNAN, X) --> fcmp ord X, Y
1876 // (fcmp ord Y, X) & (fcmp ord NNAN, X) --> fcmp ord Y, X
1877 // (fcmp ord X, Y) & (fcmp ord X, NNAN) --> fcmp ord X, Y
1878 // (fcmp ord Y, X) & (fcmp ord X, NNAN) --> fcmp ord Y, X
1879 // (fcmp uno X, Y) | (fcmp uno NNAN, X) --> fcmp uno X, Y
1880 // (fcmp uno Y, X) | (fcmp uno NNAN, X) --> fcmp uno Y, X
1881 // (fcmp uno X, Y) | (fcmp uno X, NNAN) --> fcmp uno X, Y
1882 // (fcmp uno Y, X) | (fcmp uno X, NNAN) --> fcmp uno Y, X
1883 if (((RHS1
== LHS0
|| RHS1
== LHS1
) &&
1884 isKnownNeverNaN(RHS0
, DL
, TLI
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
)) ||
1885 ((RHS0
== LHS0
|| RHS0
== LHS1
) &&
1886 isKnownNeverNaN(RHS1
, DL
, TLI
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
)))
1893 static Value
*simplifyAndOrOfCmps(const SimplifyQuery
&Q
, Value
*Op0
,
1894 Value
*Op1
, bool IsAnd
) {
1895 // Look through casts of the 'and' operands to find compares.
1896 auto *Cast0
= dyn_cast
<CastInst
>(Op0
);
1897 auto *Cast1
= dyn_cast
<CastInst
>(Op1
);
1898 if (Cast0
&& Cast1
&& Cast0
->getOpcode() == Cast1
->getOpcode() &&
1899 Cast0
->getSrcTy() == Cast1
->getSrcTy()) {
1900 Op0
= Cast0
->getOperand(0);
1901 Op1
= Cast1
->getOperand(0);
1905 auto *ICmp0
= dyn_cast
<ICmpInst
>(Op0
);
1906 auto *ICmp1
= dyn_cast
<ICmpInst
>(Op1
);
1908 V
= IsAnd
? simplifyAndOfICmps(ICmp0
, ICmp1
, Q
)
1909 : simplifyOrOfICmps(ICmp0
, ICmp1
, Q
);
1911 auto *FCmp0
= dyn_cast
<FCmpInst
>(Op0
);
1912 auto *FCmp1
= dyn_cast
<FCmpInst
>(Op1
);
1914 V
= simplifyAndOrOfFCmps(Q
, FCmp0
, FCmp1
, IsAnd
);
1921 // If we looked through casts, we can only handle a constant simplification
1922 // because we are not allowed to create a cast instruction here.
1923 if (auto *C
= dyn_cast
<Constant
>(V
))
1924 return ConstantFoldCastOperand(Cast0
->getOpcode(), C
, Cast0
->getType(),
1930 static Value
*simplifyWithOpReplaced(Value
*V
, Value
*Op
, Value
*RepOp
,
1931 const SimplifyQuery
&Q
,
1932 bool AllowRefinement
,
1933 SmallVectorImpl
<Instruction
*> *DropFlags
,
1934 unsigned MaxRecurse
);
1936 static Value
*simplifyAndOrWithICmpEq(unsigned Opcode
, Value
*Op0
, Value
*Op1
,
1937 const SimplifyQuery
&Q
,
1938 unsigned MaxRecurse
) {
1939 assert((Opcode
== Instruction::And
|| Opcode
== Instruction::Or
) &&
1941 ICmpInst::Predicate Pred
;
1943 if (!match(Op0
, m_ICmp(Pred
, m_Value(A
), m_Value(B
))) ||
1944 !ICmpInst::isEquality(Pred
))
1947 auto Simplify
= [&](Value
*Res
) -> Value
* {
1948 Constant
*Absorber
= ConstantExpr::getBinOpAbsorber(Opcode
, Res
->getType());
1950 // and (icmp eq a, b), x implies (a==b) inside x.
1951 // or (icmp ne a, b), x implies (a==b) inside x.
1952 // If x simplifies to true/false, we can simplify the and/or.
1954 (Opcode
== Instruction::And
? ICmpInst::ICMP_EQ
: ICmpInst::ICMP_NE
)) {
1955 if (Res
== Absorber
)
1957 if (Res
== ConstantExpr::getBinOpIdentity(Opcode
, Res
->getType()))
1962 // If we have and (icmp ne a, b), x and for a==b we can simplify x to false,
1963 // then we can drop the icmp, as x will already be false in the case where
1964 // the icmp is false. Similar for or and true.
1965 if (Res
== Absorber
)
1971 simplifyWithOpReplaced(Op1
, A
, B
, Q
, /* AllowRefinement */ true,
1972 /* DropFlags */ nullptr, MaxRecurse
))
1973 return Simplify(Res
);
1975 simplifyWithOpReplaced(Op1
, B
, A
, Q
, /* AllowRefinement */ true,
1976 /* DropFlags */ nullptr, MaxRecurse
))
1977 return Simplify(Res
);
1982 /// Given a bitwise logic op, check if the operands are add/sub with a common
1983 /// source value and inverted constant (identity: C - X -> ~(X + ~C)).
1984 static Value
*simplifyLogicOfAddSub(Value
*Op0
, Value
*Op1
,
1985 Instruction::BinaryOps Opcode
) {
1986 assert(Op0
->getType() == Op1
->getType() && "Mismatched binop types");
1987 assert(BinaryOperator::isBitwiseLogicOp(Opcode
) && "Expected logic op");
1990 if ((match(Op0
, m_Add(m_Value(X
), m_Constant(C1
))) &&
1991 match(Op1
, m_Sub(m_Constant(C2
), m_Specific(X
)))) ||
1992 (match(Op1
, m_Add(m_Value(X
), m_Constant(C1
))) &&
1993 match(Op0
, m_Sub(m_Constant(C2
), m_Specific(X
))))) {
1994 if (ConstantExpr::getNot(C1
) == C2
) {
1995 // (X + C) & (~C - X) --> (X + C) & ~(X + C) --> 0
1996 // (X + C) | (~C - X) --> (X + C) | ~(X + C) --> -1
1997 // (X + C) ^ (~C - X) --> (X + C) ^ ~(X + C) --> -1
1998 Type
*Ty
= Op0
->getType();
1999 return Opcode
== Instruction::And
? ConstantInt::getNullValue(Ty
)
2000 : ConstantInt::getAllOnesValue(Ty
);
2006 // Commutative patterns for and that will be tried with both operand orders.
2007 static Value
*simplifyAndCommutative(Value
*Op0
, Value
*Op1
,
2008 const SimplifyQuery
&Q
,
2009 unsigned MaxRecurse
) {
2011 if (match(Op0
, m_Not(m_Specific(Op1
))))
2012 return Constant::getNullValue(Op0
->getType());
2015 if (match(Op0
, m_c_Or(m_Specific(Op1
), m_Value())))
2018 // (X | ~Y) & (X | Y) --> X
2020 if (match(Op0
, m_c_Or(m_Value(X
), m_Not(m_Value(Y
)))) &&
2021 match(Op1
, m_c_Or(m_Deferred(X
), m_Deferred(Y
))))
2024 // If we have a multiplication overflow check that is being 'and'ed with a
2025 // check that one of the multipliers is not zero, we can omit the 'and', and
2026 // only keep the overflow check.
2027 if (isCheckForZeroAndMulWithOverflow(Op0
, Op1
, true))
2030 // -A & A = A if A is a power of two or zero.
2031 if (match(Op0
, m_Neg(m_Specific(Op1
))) &&
2032 isKnownToBeAPowerOfTwo(Op1
, Q
.DL
, /*OrZero*/ true, 0, Q
.AC
, Q
.CxtI
, Q
.DT
))
2035 // This is a similar pattern used for checking if a value is a power-of-2:
2036 // (A - 1) & A --> 0 (if A is a power-of-2 or 0)
2037 if (match(Op0
, m_Add(m_Specific(Op1
), m_AllOnes())) &&
2038 isKnownToBeAPowerOfTwo(Op1
, Q
.DL
, /*OrZero*/ true, 0, Q
.AC
, Q
.CxtI
, Q
.DT
))
2039 return Constant::getNullValue(Op1
->getType());
2041 // (x << N) & ((x << M) - 1) --> 0, where x is known to be a power of 2 and
2043 const APInt
*Shift1
, *Shift2
;
2044 if (match(Op0
, m_Shl(m_Value(X
), m_APInt(Shift1
))) &&
2045 match(Op1
, m_Add(m_Shl(m_Specific(X
), m_APInt(Shift2
)), m_AllOnes())) &&
2046 isKnownToBeAPowerOfTwo(X
, Q
.DL
, /*OrZero*/ true, /*Depth*/ 0, Q
.AC
,
2048 Shift1
->uge(*Shift2
))
2049 return Constant::getNullValue(Op0
->getType());
2052 simplifyAndOrWithICmpEq(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2058 /// Given operands for an And, see if we can fold the result.
2059 /// If not, this returns null.
2060 static Value
*simplifyAndInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
2061 unsigned MaxRecurse
) {
2062 if (Constant
*C
= foldOrCommuteConstant(Instruction::And
, Op0
, Op1
, Q
))
2065 // X & poison -> poison
2066 if (isa
<PoisonValue
>(Op1
))
2070 if (Q
.isUndefValue(Op1
))
2071 return Constant::getNullValue(Op0
->getType());
2078 if (match(Op1
, m_Zero()))
2079 return Constant::getNullValue(Op0
->getType());
2082 if (match(Op1
, m_AllOnes()))
2085 if (Value
*Res
= simplifyAndCommutative(Op0
, Op1
, Q
, MaxRecurse
))
2087 if (Value
*Res
= simplifyAndCommutative(Op1
, Op0
, Q
, MaxRecurse
))
2090 if (Value
*V
= simplifyLogicOfAddSub(Op0
, Op1
, Instruction::And
))
2093 // A mask that only clears known zeros of a shifted value is a no-op.
2097 if (match(Op1
, m_APInt(Mask
))) {
2098 // If all bits in the inverted and shifted mask are clear:
2099 // and (shl X, ShAmt), Mask --> shl X, ShAmt
2100 if (match(Op0
, m_Shl(m_Value(X
), m_APInt(ShAmt
))) &&
2101 (~(*Mask
)).lshr(*ShAmt
).isZero())
2104 // If all bits in the inverted and shifted mask are clear:
2105 // and (lshr X, ShAmt), Mask --> lshr X, ShAmt
2106 if (match(Op0
, m_LShr(m_Value(X
), m_APInt(ShAmt
))) &&
2107 (~(*Mask
)).shl(*ShAmt
).isZero())
2111 // and 2^x-1, 2^C --> 0 where x <= C.
2112 const APInt
*PowerC
;
2114 if (match(Op1
, m_Power2(PowerC
)) &&
2115 match(Op0
, m_Add(m_Value(Shift
), m_AllOnes())) &&
2116 isKnownToBeAPowerOfTwo(Shift
, Q
.DL
, /*OrZero*/ false, 0, Q
.AC
, Q
.CxtI
,
2118 KnownBits Known
= computeKnownBits(Shift
, /* Depth */ 0, Q
);
2119 // Use getActiveBits() to make use of the additional power of two knowledge
2120 if (PowerC
->getActiveBits() >= Known
.getMaxValue().getActiveBits())
2121 return ConstantInt::getNullValue(Op1
->getType());
2124 if (Value
*V
= simplifyAndOrOfCmps(Q
, Op0
, Op1
, true))
2127 // Try some generic simplifications for associative operations.
2129 simplifyAssociativeBinOp(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2132 // And distributes over Or. Try some generic simplifications based on this.
2133 if (Value
*V
= expandCommutativeBinOp(Instruction::And
, Op0
, Op1
,
2134 Instruction::Or
, Q
, MaxRecurse
))
2137 // And distributes over Xor. Try some generic simplifications based on this.
2138 if (Value
*V
= expandCommutativeBinOp(Instruction::And
, Op0
, Op1
,
2139 Instruction::Xor
, Q
, MaxRecurse
))
2142 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
)) {
2143 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2144 // A & (A && B) -> A && B
2145 if (match(Op1
, m_Select(m_Specific(Op0
), m_Value(), m_Zero())))
2147 else if (match(Op0
, m_Select(m_Specific(Op1
), m_Value(), m_Zero())))
2150 // If the operation is with the result of a select instruction, check
2151 // whether operating on either branch of the select always yields the same
2154 threadBinOpOverSelect(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2158 // If the operation is with the result of a phi instruction, check whether
2159 // operating on all incoming values of the phi always yields the same value.
2160 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
2162 threadBinOpOverPHI(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2165 // Assuming the effective width of Y is not larger than A, i.e. all bits
2166 // from X and Y are disjoint in (X << A) | Y,
2167 // if the mask of this AND op covers all bits of X or Y, while it covers
2168 // no bits from the other, we can bypass this AND op. E.g.,
2169 // ((X << A) | Y) & Mask -> Y,
2170 // if Mask = ((1 << effective_width_of(Y)) - 1)
2171 // ((X << A) | Y) & Mask -> X << A,
2172 // if Mask = ((1 << effective_width_of(X)) - 1) << A
2173 // SimplifyDemandedBits in InstCombine can optimize the general case.
2174 // This pattern aims to help other passes for a common case.
2176 if (Q
.IIQ
.UseInstrInfo
&& match(Op1
, m_APInt(Mask
)) &&
2177 match(Op0
, m_c_Or(m_CombineAnd(m_NUWShl(m_Value(X
), m_APInt(ShAmt
)),
2180 const unsigned Width
= Op0
->getType()->getScalarSizeInBits();
2181 const unsigned ShftCnt
= ShAmt
->getLimitedValue(Width
);
2182 const KnownBits YKnown
= computeKnownBits(Y
, /* Depth */ 0, Q
);
2183 const unsigned EffWidthY
= YKnown
.countMaxActiveBits();
2184 if (EffWidthY
<= ShftCnt
) {
2185 const KnownBits XKnown
= computeKnownBits(X
, /* Depth */ 0, Q
);
2186 const unsigned EffWidthX
= XKnown
.countMaxActiveBits();
2187 const APInt EffBitsY
= APInt::getLowBitsSet(Width
, EffWidthY
);
2188 const APInt EffBitsX
= APInt::getLowBitsSet(Width
, EffWidthX
) << ShftCnt
;
2189 // If the mask is extracting all bits from X or Y as is, we can skip
2191 if (EffBitsY
.isSubsetOf(*Mask
) && !EffBitsX
.intersects(*Mask
))
2193 if (EffBitsX
.isSubsetOf(*Mask
) && !EffBitsY
.intersects(*Mask
))
2198 // ((X | Y) ^ X ) & ((X | Y) ^ Y) --> 0
2199 // ((X | Y) ^ Y ) & ((X | Y) ^ X) --> 0
2201 if (match(Op0
, m_c_Xor(m_Value(X
),
2202 m_CombineAnd(m_BinOp(Or
),
2203 m_c_Or(m_Deferred(X
), m_Value(Y
))))) &&
2204 match(Op1
, m_c_Xor(m_Specific(Or
), m_Specific(Y
))))
2205 return Constant::getNullValue(Op0
->getType());
2209 // (A ^ C) & (A ^ ~C) -> 0
2210 if (match(Op0
, m_Xor(m_Value(A
), m_APInt(C1
))) &&
2211 match(Op1
, m_Xor(m_Specific(A
), m_SpecificInt(~*C1
))))
2212 return Constant::getNullValue(Op0
->getType());
2214 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2215 if (std::optional
<bool> Implied
= isImpliedCondition(Op0
, Op1
, Q
.DL
)) {
2216 // If Op0 is true implies Op1 is true, then Op0 is a subset of Op1.
2217 if (*Implied
== true)
2219 // If Op0 is true implies Op1 is false, then they are not true together.
2220 if (*Implied
== false)
2221 return ConstantInt::getFalse(Op0
->getType());
2223 if (std::optional
<bool> Implied
= isImpliedCondition(Op1
, Op0
, Q
.DL
)) {
2224 // If Op1 is true implies Op0 is true, then Op1 is a subset of Op0.
2227 // If Op1 is true implies Op0 is false, then they are not true together.
2229 return ConstantInt::getFalse(Op1
->getType());
2233 if (Value
*V
= simplifyByDomEq(Instruction::And
, Op0
, Op1
, Q
, MaxRecurse
))
2239 Value
*llvm::simplifyAndInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
2240 return ::simplifyAndInst(Op0
, Op1
, Q
, RecursionLimit
);
2243 // TODO: Many of these folds could use LogicalAnd/LogicalOr.
2244 static Value
*simplifyOrLogic(Value
*X
, Value
*Y
) {
2245 assert(X
->getType() == Y
->getType() && "Expected same type for 'or' ops");
2246 Type
*Ty
= X
->getType();
2249 if (match(Y
, m_Not(m_Specific(X
))))
2250 return ConstantInt::getAllOnesValue(Ty
);
2252 // X | ~(X & ?) = -1
2253 if (match(Y
, m_Not(m_c_And(m_Specific(X
), m_Value()))))
2254 return ConstantInt::getAllOnesValue(Ty
);
2256 // X | (X & ?) --> X
2257 if (match(Y
, m_c_And(m_Specific(X
), m_Value())))
2262 // (A ^ B) | (A | B) --> A | B
2263 // (A ^ B) | (B | A) --> B | A
2264 if (match(X
, m_Xor(m_Value(A
), m_Value(B
))) &&
2265 match(Y
, m_c_Or(m_Specific(A
), m_Specific(B
))))
2268 // ~(A ^ B) | (A | B) --> -1
2269 // ~(A ^ B) | (B | A) --> -1
2270 if (match(X
, m_Not(m_Xor(m_Value(A
), m_Value(B
)))) &&
2271 match(Y
, m_c_Or(m_Specific(A
), m_Specific(B
))))
2272 return ConstantInt::getAllOnesValue(Ty
);
2274 // (A & ~B) | (A ^ B) --> A ^ B
2275 // (~B & A) | (A ^ B) --> A ^ B
2276 // (A & ~B) | (B ^ A) --> B ^ A
2277 // (~B & A) | (B ^ A) --> B ^ A
2278 if (match(X
, m_c_And(m_Value(A
), m_Not(m_Value(B
)))) &&
2279 match(Y
, m_c_Xor(m_Specific(A
), m_Specific(B
))))
2282 // (~A ^ B) | (A & B) --> ~A ^ B
2283 // (B ^ ~A) | (A & B) --> B ^ ~A
2284 // (~A ^ B) | (B & A) --> ~A ^ B
2285 // (B ^ ~A) | (B & A) --> B ^ ~A
2286 if (match(X
, m_c_Xor(m_NotForbidUndef(m_Value(A
)), m_Value(B
))) &&
2287 match(Y
, m_c_And(m_Specific(A
), m_Specific(B
))))
2290 // (~A | B) | (A ^ B) --> -1
2291 // (~A | B) | (B ^ A) --> -1
2292 // (B | ~A) | (A ^ B) --> -1
2293 // (B | ~A) | (B ^ A) --> -1
2294 if (match(X
, m_c_Or(m_Not(m_Value(A
)), m_Value(B
))) &&
2295 match(Y
, m_c_Xor(m_Specific(A
), m_Specific(B
))))
2296 return ConstantInt::getAllOnesValue(Ty
);
2298 // (~A & B) | ~(A | B) --> ~A
2299 // (~A & B) | ~(B | A) --> ~A
2300 // (B & ~A) | ~(A | B) --> ~A
2301 // (B & ~A) | ~(B | A) --> ~A
2304 m_c_And(m_CombineAnd(m_Value(NotA
), m_NotForbidUndef(m_Value(A
))),
2306 match(Y
, m_Not(m_c_Or(m_Specific(A
), m_Specific(B
)))))
2308 // The same is true of Logical And
2309 // TODO: This could share the logic of the version above if there was a
2310 // version of LogicalAnd that allowed more than just i1 types.
2311 if (match(X
, m_c_LogicalAnd(
2312 m_CombineAnd(m_Value(NotA
), m_NotForbidUndef(m_Value(A
))),
2314 match(Y
, m_Not(m_c_LogicalOr(m_Specific(A
), m_Specific(B
)))))
2317 // ~(A ^ B) | (A & B) --> ~(A ^ B)
2318 // ~(A ^ B) | (B & A) --> ~(A ^ B)
2320 if (match(X
, m_CombineAnd(m_NotForbidUndef(m_Xor(m_Value(A
), m_Value(B
))),
2322 match(Y
, m_c_And(m_Specific(A
), m_Specific(B
))))
2325 // ~(A & B) | (A ^ B) --> ~(A & B)
2326 // ~(A & B) | (B ^ A) --> ~(A & B)
2327 if (match(X
, m_CombineAnd(m_NotForbidUndef(m_And(m_Value(A
), m_Value(B
))),
2329 match(Y
, m_c_Xor(m_Specific(A
), m_Specific(B
))))
2335 /// Given operands for an Or, see if we can fold the result.
2336 /// If not, this returns null.
2337 static Value
*simplifyOrInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
2338 unsigned MaxRecurse
) {
2339 if (Constant
*C
= foldOrCommuteConstant(Instruction::Or
, Op0
, Op1
, Q
))
2342 // X | poison -> poison
2343 if (isa
<PoisonValue
>(Op1
))
2348 // Do not return Op1 because it may contain undef elements if it's a vector.
2349 if (Q
.isUndefValue(Op1
) || match(Op1
, m_AllOnes()))
2350 return Constant::getAllOnesValue(Op0
->getType());
2354 if (Op0
== Op1
|| match(Op1
, m_Zero()))
2357 if (Value
*R
= simplifyOrLogic(Op0
, Op1
))
2359 if (Value
*R
= simplifyOrLogic(Op1
, Op0
))
2362 if (Value
*V
= simplifyLogicOfAddSub(Op0
, Op1
, Instruction::Or
))
2365 // Rotated -1 is still -1:
2366 // (-1 << X) | (-1 >> (C - X)) --> -1
2367 // (-1 >> X) | (-1 << (C - X)) --> -1
2368 // ...with C <= bitwidth (and commuted variants).
2370 if ((match(Op0
, m_Shl(m_AllOnes(), m_Value(X
))) &&
2371 match(Op1
, m_LShr(m_AllOnes(), m_Value(Y
)))) ||
2372 (match(Op1
, m_Shl(m_AllOnes(), m_Value(X
))) &&
2373 match(Op0
, m_LShr(m_AllOnes(), m_Value(Y
))))) {
2375 if ((match(X
, m_Sub(m_APInt(C
), m_Specific(Y
))) ||
2376 match(Y
, m_Sub(m_APInt(C
), m_Specific(X
)))) &&
2377 C
->ule(X
->getType()->getScalarSizeInBits())) {
2378 return ConstantInt::getAllOnesValue(X
->getType());
2382 // A funnel shift (rotate) can be decomposed into simpler shifts. See if we
2383 // are mixing in another shift that is redundant with the funnel shift.
2385 // (fshl X, ?, Y) | (shl X, Y) --> fshl X, ?, Y
2386 // (shl X, Y) | (fshl X, ?, Y) --> fshl X, ?, Y
2388 m_Intrinsic
<Intrinsic::fshl
>(m_Value(X
), m_Value(), m_Value(Y
))) &&
2389 match(Op1
, m_Shl(m_Specific(X
), m_Specific(Y
))))
2392 m_Intrinsic
<Intrinsic::fshl
>(m_Value(X
), m_Value(), m_Value(Y
))) &&
2393 match(Op0
, m_Shl(m_Specific(X
), m_Specific(Y
))))
2396 // (fshr ?, X, Y) | (lshr X, Y) --> fshr ?, X, Y
2397 // (lshr X, Y) | (fshr ?, X, Y) --> fshr ?, X, Y
2399 m_Intrinsic
<Intrinsic::fshr
>(m_Value(), m_Value(X
), m_Value(Y
))) &&
2400 match(Op1
, m_LShr(m_Specific(X
), m_Specific(Y
))))
2403 m_Intrinsic
<Intrinsic::fshr
>(m_Value(), m_Value(X
), m_Value(Y
))) &&
2404 match(Op0
, m_LShr(m_Specific(X
), m_Specific(Y
))))
2408 simplifyAndOrWithICmpEq(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2411 simplifyAndOrWithICmpEq(Instruction::Or
, Op1
, Op0
, Q
, MaxRecurse
))
2414 if (Value
*V
= simplifyAndOrOfCmps(Q
, Op0
, Op1
, false))
2417 // If we have a multiplication overflow check that is being 'and'ed with a
2418 // check that one of the multipliers is not zero, we can omit the 'and', and
2419 // only keep the overflow check.
2420 if (isCheckForZeroAndMulWithOverflow(Op0
, Op1
, false))
2422 if (isCheckForZeroAndMulWithOverflow(Op1
, Op0
, false))
2425 // Try some generic simplifications for associative operations.
2427 simplifyAssociativeBinOp(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2430 // Or distributes over And. Try some generic simplifications based on this.
2431 if (Value
*V
= expandCommutativeBinOp(Instruction::Or
, Op0
, Op1
,
2432 Instruction::And
, Q
, MaxRecurse
))
2435 if (isa
<SelectInst
>(Op0
) || isa
<SelectInst
>(Op1
)) {
2436 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2437 // A | (A || B) -> A || B
2438 if (match(Op1
, m_Select(m_Specific(Op0
), m_One(), m_Value())))
2440 else if (match(Op0
, m_Select(m_Specific(Op1
), m_One(), m_Value())))
2443 // If the operation is with the result of a select instruction, check
2444 // whether operating on either branch of the select always yields the same
2447 threadBinOpOverSelect(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2451 // (A & C1)|(B & C2)
2453 const APInt
*C1
, *C2
;
2454 if (match(Op0
, m_And(m_Value(A
), m_APInt(C1
))) &&
2455 match(Op1
, m_And(m_Value(B
), m_APInt(C2
)))) {
2457 // (A & C1)|(B & C2)
2458 // If we have: ((V + N) & C1) | (V & C2)
2459 // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
2460 // replace with V+N.
2462 if (C2
->isMask() && // C2 == 0+1+
2463 match(A
, m_c_Add(m_Specific(B
), m_Value(N
)))) {
2464 // Add commutes, try both ways.
2465 if (MaskedValueIsZero(N
, *C2
, Q
))
2468 // Or commutes, try both ways.
2469 if (C1
->isMask() && match(B
, m_c_Add(m_Specific(A
), m_Value(N
)))) {
2470 // Add commutes, try both ways.
2471 if (MaskedValueIsZero(N
, *C1
, Q
))
2477 // If the operation is with the result of a phi instruction, check whether
2478 // operating on all incoming values of the phi always yields the same value.
2479 if (isa
<PHINode
>(Op0
) || isa
<PHINode
>(Op1
))
2480 if (Value
*V
= threadBinOpOverPHI(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2483 // (A ^ C) | (A ^ ~C) -> -1, i.e. all bits set to one.
2484 if (match(Op0
, m_Xor(m_Value(A
), m_APInt(C1
))) &&
2485 match(Op1
, m_Xor(m_Specific(A
), m_SpecificInt(~*C1
))))
2486 return Constant::getAllOnesValue(Op0
->getType());
2488 if (Op0
->getType()->isIntOrIntVectorTy(1)) {
2489 if (std::optional
<bool> Implied
=
2490 isImpliedCondition(Op0
, Op1
, Q
.DL
, false)) {
2491 // If Op0 is false implies Op1 is false, then Op1 is a subset of Op0.
2492 if (*Implied
== false)
2494 // If Op0 is false implies Op1 is true, then at least one is always true.
2495 if (*Implied
== true)
2496 return ConstantInt::getTrue(Op0
->getType());
2498 if (std::optional
<bool> Implied
=
2499 isImpliedCondition(Op1
, Op0
, Q
.DL
, false)) {
2500 // If Op1 is false implies Op0 is false, then Op0 is a subset of Op1.
2501 if (*Implied
== false)
2503 // If Op1 is false implies Op0 is true, then at least one is always true.
2504 if (*Implied
== true)
2505 return ConstantInt::getTrue(Op1
->getType());
2509 if (Value
*V
= simplifyByDomEq(Instruction::Or
, Op0
, Op1
, Q
, MaxRecurse
))
2515 Value
*llvm::simplifyOrInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
2516 return ::simplifyOrInst(Op0
, Op1
, Q
, RecursionLimit
);
2519 /// Given operands for a Xor, see if we can fold the result.
2520 /// If not, this returns null.
2521 static Value
*simplifyXorInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
2522 unsigned MaxRecurse
) {
2523 if (Constant
*C
= foldOrCommuteConstant(Instruction::Xor
, Op0
, Op1
, Q
))
2526 // X ^ poison -> poison
2527 if (isa
<PoisonValue
>(Op1
))
2530 // A ^ undef -> undef
2531 if (Q
.isUndefValue(Op1
))
2535 if (match(Op1
, m_Zero()))
2540 return Constant::getNullValue(Op0
->getType());
2542 // A ^ ~A = ~A ^ A = -1
2543 if (match(Op0
, m_Not(m_Specific(Op1
))) || match(Op1
, m_Not(m_Specific(Op0
))))
2544 return Constant::getAllOnesValue(Op0
->getType());
2546 auto foldAndOrNot
= [](Value
*X
, Value
*Y
) -> Value
* {
2548 // (~A & B) ^ (A | B) --> A -- There are 8 commuted variants.
2549 if (match(X
, m_c_And(m_Not(m_Value(A
)), m_Value(B
))) &&
2550 match(Y
, m_c_Or(m_Specific(A
), m_Specific(B
))))
2553 // (~A | B) ^ (A & B) --> ~A -- There are 8 commuted variants.
2554 // The 'not' op must contain a complete -1 operand (no undef elements for
2555 // vector) for the transform to be safe.
2558 m_c_Or(m_CombineAnd(m_NotForbidUndef(m_Value(A
)), m_Value(NotA
)),
2560 match(Y
, m_c_And(m_Specific(A
), m_Specific(B
))))
2565 if (Value
*R
= foldAndOrNot(Op0
, Op1
))
2567 if (Value
*R
= foldAndOrNot(Op1
, Op0
))
2570 if (Value
*V
= simplifyLogicOfAddSub(Op0
, Op1
, Instruction::Xor
))
2573 // Try some generic simplifications for associative operations.
2575 simplifyAssociativeBinOp(Instruction::Xor
, Op0
, Op1
, Q
, MaxRecurse
))
2578 // Threading Xor over selects and phi nodes is pointless, so don't bother.
2579 // Threading over the select in "A ^ select(cond, B, C)" means evaluating
2580 // "A^B" and "A^C" and seeing if they are equal; but they are equal if and
2581 // only if B and C are equal. If B and C are equal then (since we assume
2582 // that operands have already been simplified) "select(cond, B, C)" should
2583 // have been simplified to the common value of B and C already. Analysing
2584 // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
2585 // for threading over phi nodes.
2587 if (Value
*V
= simplifyByDomEq(Instruction::Xor
, Op0
, Op1
, Q
, MaxRecurse
))
2593 Value
*llvm::simplifyXorInst(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
) {
2594 return ::simplifyXorInst(Op0
, Op1
, Q
, RecursionLimit
);
2597 static Type
*getCompareTy(Value
*Op
) {
2598 return CmpInst::makeCmpResultType(Op
->getType());
2601 /// Rummage around inside V looking for something equivalent to the comparison
2602 /// "LHS Pred RHS". Return such a value if found, otherwise return null.
2603 /// Helper function for analyzing max/min idioms.
2604 static Value
*extractEquivalentCondition(Value
*V
, CmpInst::Predicate Pred
,
2605 Value
*LHS
, Value
*RHS
) {
2606 SelectInst
*SI
= dyn_cast
<SelectInst
>(V
);
2609 CmpInst
*Cmp
= dyn_cast
<CmpInst
>(SI
->getCondition());
2612 Value
*CmpLHS
= Cmp
->getOperand(0), *CmpRHS
= Cmp
->getOperand(1);
2613 if (Pred
== Cmp
->getPredicate() && LHS
== CmpLHS
&& RHS
== CmpRHS
)
2615 if (Pred
== CmpInst::getSwappedPredicate(Cmp
->getPredicate()) &&
2616 LHS
== CmpRHS
&& RHS
== CmpLHS
)
2621 /// Return true if the underlying object (storage) must be disjoint from
2622 /// storage returned by any noalias return call.
2623 static bool isAllocDisjoint(const Value
*V
) {
2624 // For allocas, we consider only static ones (dynamic
2625 // allocas might be transformed into calls to malloc not simultaneously
2626 // live with the compared-to allocation). For globals, we exclude symbols
2627 // that might be resolve lazily to symbols in another dynamically-loaded
2628 // library (and, thus, could be malloc'ed by the implementation).
2629 if (const AllocaInst
*AI
= dyn_cast
<AllocaInst
>(V
))
2630 return AI
->isStaticAlloca();
2631 if (const GlobalValue
*GV
= dyn_cast
<GlobalValue
>(V
))
2632 return (GV
->hasLocalLinkage() || GV
->hasHiddenVisibility() ||
2633 GV
->hasProtectedVisibility() || GV
->hasGlobalUnnamedAddr()) &&
2634 !GV
->isThreadLocal();
2635 if (const Argument
*A
= dyn_cast
<Argument
>(V
))
2636 return A
->hasByValAttr();
2640 /// Return true if V1 and V2 are each the base of some distict storage region
2641 /// [V, object_size(V)] which do not overlap. Note that zero sized regions
2642 /// *are* possible, and that zero sized regions do not overlap with any other.
2643 static bool haveNonOverlappingStorage(const Value
*V1
, const Value
*V2
) {
2644 // Global variables always exist, so they always exist during the lifetime
2645 // of each other and all allocas. Global variables themselves usually have
2646 // non-overlapping storage, but since their addresses are constants, the
2647 // case involving two globals does not reach here and is instead handled in
2648 // constant folding.
2650 // Two different allocas usually have different addresses...
2652 // However, if there's an @llvm.stackrestore dynamically in between two
2653 // allocas, they may have the same address. It's tempting to reduce the
2654 // scope of the problem by only looking at *static* allocas here. That would
2655 // cover the majority of allocas while significantly reducing the likelihood
2656 // of having an @llvm.stackrestore pop up in the middle. However, it's not
2657 // actually impossible for an @llvm.stackrestore to pop up in the middle of
2658 // an entry block. Also, if we have a block that's not attached to a
2659 // function, we can't tell if it's "static" under the current definition.
2660 // Theoretically, this problem could be fixed by creating a new kind of
2661 // instruction kind specifically for static allocas. Such a new instruction
2662 // could be required to be at the top of the entry block, thus preventing it
2663 // from being subject to a @llvm.stackrestore. Instcombine could even
2664 // convert regular allocas into these special allocas. It'd be nifty.
2665 // However, until then, this problem remains open.
2667 // So, we'll assume that two non-empty allocas have different addresses
2669 auto isByValArg
= [](const Value
*V
) {
2670 const Argument
*A
= dyn_cast
<Argument
>(V
);
2671 return A
&& A
->hasByValAttr();
2674 // Byval args are backed by store which does not overlap with each other,
2675 // allocas, or globals.
2677 return isa
<AllocaInst
>(V2
) || isa
<GlobalVariable
>(V2
) || isByValArg(V2
);
2679 return isa
<AllocaInst
>(V1
) || isa
<GlobalVariable
>(V1
) || isByValArg(V1
);
2681 return isa
<AllocaInst
>(V1
) &&
2682 (isa
<AllocaInst
>(V2
) || isa
<GlobalVariable
>(V2
));
2685 // A significant optimization not implemented here is assuming that alloca
2686 // addresses are not equal to incoming argument values. They don't *alias*,
2687 // as we say, but that doesn't mean they aren't equal, so we take a
2688 // conservative approach.
2690 // This is inspired in part by C++11 5.10p1:
2691 // "Two pointers of the same type compare equal if and only if they are both
2692 // null, both point to the same function, or both represent the same
2695 // This is pretty permissive.
2697 // It's also partly due to C11 6.5.9p6:
2698 // "Two pointers compare equal if and only if both are null pointers, both are
2699 // pointers to the same object (including a pointer to an object and a
2700 // subobject at its beginning) or function, both are pointers to one past the
2701 // last element of the same array object, or one is a pointer to one past the
2702 // end of one array object and the other is a pointer to the start of a
2703 // different array object that happens to immediately follow the first array
2704 // object in the address space.)
2706 // C11's version is more restrictive, however there's no reason why an argument
2707 // couldn't be a one-past-the-end value for a stack object in the caller and be
2708 // equal to the beginning of a stack object in the callee.
2710 // If the C and C++ standards are ever made sufficiently restrictive in this
2711 // area, it may be possible to update LLVM's semantics accordingly and reinstate
2712 // this optimization.
2713 static Constant
*computePointerICmp(CmpInst::Predicate Pred
, Value
*LHS
,
2714 Value
*RHS
, const SimplifyQuery
&Q
) {
2715 assert(LHS
->getType() == RHS
->getType() && "Must have same types");
2716 const DataLayout
&DL
= Q
.DL
;
2717 const TargetLibraryInfo
*TLI
= Q
.TLI
;
2718 const DominatorTree
*DT
= Q
.DT
;
2719 const Instruction
*CxtI
= Q
.CxtI
;
2721 // We can only fold certain predicates on pointer comparisons.
2726 // Equality comparisons are easy to fold.
2727 case CmpInst::ICMP_EQ
:
2728 case CmpInst::ICMP_NE
:
2731 // We can only handle unsigned relational comparisons because 'inbounds' on
2732 // a GEP only protects against unsigned wrapping.
2733 case CmpInst::ICMP_UGT
:
2734 case CmpInst::ICMP_UGE
:
2735 case CmpInst::ICMP_ULT
:
2736 case CmpInst::ICMP_ULE
:
2737 // However, we have to switch them to their signed variants to handle
2738 // negative indices from the base pointer.
2739 Pred
= ICmpInst::getSignedPredicate(Pred
);
2743 // Strip off any constant offsets so that we can reason about them.
2744 // It's tempting to use getUnderlyingObject or even just stripInBoundsOffsets
2745 // here and compare base addresses like AliasAnalysis does, however there are
2746 // numerous hazards. AliasAnalysis and its utilities rely on special rules
2747 // governing loads and stores which don't apply to icmps. Also, AliasAnalysis
2748 // doesn't need to guarantee pointer inequality when it says NoAlias.
2750 // Even if an non-inbounds GEP occurs along the path we can still optimize
2751 // equality comparisons concerning the result.
2752 bool AllowNonInbounds
= ICmpInst::isEquality(Pred
);
2753 unsigned IndexSize
= DL
.getIndexTypeSizeInBits(LHS
->getType());
2754 APInt
LHSOffset(IndexSize
, 0), RHSOffset(IndexSize
, 0);
2755 LHS
= LHS
->stripAndAccumulateConstantOffsets(DL
, LHSOffset
, AllowNonInbounds
);
2756 RHS
= RHS
->stripAndAccumulateConstantOffsets(DL
, RHSOffset
, AllowNonInbounds
);
2758 // If LHS and RHS are related via constant offsets to the same base
2759 // value, we can replace it with an icmp which just compares the offsets.
2761 return ConstantInt::get(getCompareTy(LHS
),
2762 ICmpInst::compare(LHSOffset
, RHSOffset
, Pred
));
2764 // Various optimizations for (in)equality comparisons.
2765 if (Pred
== CmpInst::ICMP_EQ
|| Pred
== CmpInst::ICMP_NE
) {
2766 // Different non-empty allocations that exist at the same time have
2767 // different addresses (if the program can tell). If the offsets are
2768 // within the bounds of their allocations (and not one-past-the-end!
2769 // so we can't use inbounds!), and their allocations aren't the same,
2770 // the pointers are not equal.
2771 if (haveNonOverlappingStorage(LHS
, RHS
)) {
2772 uint64_t LHSSize
, RHSSize
;
2773 ObjectSizeOpts Opts
;
2774 Opts
.EvalMode
= ObjectSizeOpts::Mode::Min
;
2775 auto *F
= [](Value
*V
) -> Function
* {
2776 if (auto *I
= dyn_cast
<Instruction
>(V
))
2777 return I
->getFunction();
2778 if (auto *A
= dyn_cast
<Argument
>(V
))
2779 return A
->getParent();
2782 Opts
.NullIsUnknownSize
= F
? NullPointerIsDefined(F
) : true;
2783 if (getObjectSize(LHS
, LHSSize
, DL
, TLI
, Opts
) &&
2784 getObjectSize(RHS
, RHSSize
, DL
, TLI
, Opts
)) {
2785 APInt Dist
= LHSOffset
- RHSOffset
;
2786 if (Dist
.isNonNegative() ? Dist
.ult(LHSSize
) : (-Dist
).ult(RHSSize
))
2787 return ConstantInt::get(getCompareTy(LHS
),
2788 !CmpInst::isTrueWhenEqual(Pred
));
2792 // If one side of the equality comparison must come from a noalias call
2793 // (meaning a system memory allocation function), and the other side must
2794 // come from a pointer that cannot overlap with dynamically-allocated
2795 // memory within the lifetime of the current function (allocas, byval
2796 // arguments, globals), then determine the comparison result here.
2797 SmallVector
<const Value
*, 8> LHSUObjs
, RHSUObjs
;
2798 getUnderlyingObjects(LHS
, LHSUObjs
);
2799 getUnderlyingObjects(RHS
, RHSUObjs
);
2801 // Is the set of underlying objects all noalias calls?
2802 auto IsNAC
= [](ArrayRef
<const Value
*> Objects
) {
2803 return all_of(Objects
, isNoAliasCall
);
2806 // Is the set of underlying objects all things which must be disjoint from
2807 // noalias calls. We assume that indexing from such disjoint storage
2808 // into the heap is undefined, and thus offsets can be safely ignored.
2809 auto IsAllocDisjoint
= [](ArrayRef
<const Value
*> Objects
) {
2810 return all_of(Objects
, ::isAllocDisjoint
);
2813 if ((IsNAC(LHSUObjs
) && IsAllocDisjoint(RHSUObjs
)) ||
2814 (IsNAC(RHSUObjs
) && IsAllocDisjoint(LHSUObjs
)))
2815 return ConstantInt::get(getCompareTy(LHS
),
2816 !CmpInst::isTrueWhenEqual(Pred
));
2818 // Fold comparisons for non-escaping pointer even if the allocation call
2819 // cannot be elided. We cannot fold malloc comparison to null. Also, the
2820 // dynamic allocation call could be either of the operands. Note that
2821 // the other operand can not be based on the alloc - if it were, then
2822 // the cmp itself would be a capture.
2823 Value
*MI
= nullptr;
2824 if (isAllocLikeFn(LHS
, TLI
) &&
2825 llvm::isKnownNonZero(RHS
, DL
, 0, nullptr, CxtI
, DT
))
2827 else if (isAllocLikeFn(RHS
, TLI
) &&
2828 llvm::isKnownNonZero(LHS
, DL
, 0, nullptr, CxtI
, DT
))
2831 // FIXME: This is incorrect, see PR54002. While we can assume that the
2832 // allocation is at an address that makes the comparison false, this
2833 // requires that *all* comparisons to that address be false, which
2834 // InstSimplify cannot guarantee.
2835 struct CustomCaptureTracker
: public CaptureTracker
{
2836 bool Captured
= false;
2837 void tooManyUses() override
{ Captured
= true; }
2838 bool captured(const Use
*U
) override
{
2839 if (auto *ICmp
= dyn_cast
<ICmpInst
>(U
->getUser())) {
2840 // Comparison against value stored in global variable. Given the
2841 // pointer does not escape, its value cannot be guessed and stored
2842 // separately in a global variable.
2843 unsigned OtherIdx
= 1 - U
->getOperandNo();
2844 auto *LI
= dyn_cast
<LoadInst
>(ICmp
->getOperand(OtherIdx
));
2845 if (LI
&& isa
<GlobalVariable
>(LI
->getPointerOperand()))
2853 CustomCaptureTracker Tracker
;
2854 PointerMayBeCaptured(MI
, &Tracker
);
2855 if (!Tracker
.Captured
)
2856 return ConstantInt::get(getCompareTy(LHS
),
2857 CmpInst::isFalseWhenEqual(Pred
));
2865 /// Fold an icmp when its operands have i1 scalar type.
2866 static Value
*simplifyICmpOfBools(CmpInst::Predicate Pred
, Value
*LHS
,
2867 Value
*RHS
, const SimplifyQuery
&Q
) {
2868 Type
*ITy
= getCompareTy(LHS
); // The return type.
2869 Type
*OpTy
= LHS
->getType(); // The operand type.
2870 if (!OpTy
->isIntOrIntVectorTy(1))
2873 // A boolean compared to true/false can be reduced in 14 out of the 20
2874 // (10 predicates * 2 constants) possible combinations. The other
2875 // 6 cases require a 'not' of the LHS.
2877 auto ExtractNotLHS
= [](Value
*V
) -> Value
* {
2879 if (match(V
, m_Not(m_Value(X
))))
2884 if (match(RHS
, m_Zero())) {
2886 case CmpInst::ICMP_NE
: // X != 0 -> X
2887 case CmpInst::ICMP_UGT
: // X >u 0 -> X
2888 case CmpInst::ICMP_SLT
: // X <s 0 -> X
2891 case CmpInst::ICMP_EQ
: // not(X) == 0 -> X != 0 -> X
2892 case CmpInst::ICMP_ULE
: // not(X) <=u 0 -> X >u 0 -> X
2893 case CmpInst::ICMP_SGE
: // not(X) >=s 0 -> X <s 0 -> X
2894 if (Value
*X
= ExtractNotLHS(LHS
))
2898 case CmpInst::ICMP_ULT
: // X <u 0 -> false
2899 case CmpInst::ICMP_SGT
: // X >s 0 -> false
2900 return getFalse(ITy
);
2902 case CmpInst::ICMP_UGE
: // X >=u 0 -> true
2903 case CmpInst::ICMP_SLE
: // X <=s 0 -> true
2904 return getTrue(ITy
);
2909 } else if (match(RHS
, m_One())) {
2911 case CmpInst::ICMP_EQ
: // X == 1 -> X
2912 case CmpInst::ICMP_UGE
: // X >=u 1 -> X
2913 case CmpInst::ICMP_SLE
: // X <=s -1 -> X
2916 case CmpInst::ICMP_NE
: // not(X) != 1 -> X == 1 -> X
2917 case CmpInst::ICMP_ULT
: // not(X) <=u 1 -> X >=u 1 -> X
2918 case CmpInst::ICMP_SGT
: // not(X) >s 1 -> X <=s -1 -> X
2919 if (Value
*X
= ExtractNotLHS(LHS
))
2923 case CmpInst::ICMP_UGT
: // X >u 1 -> false
2924 case CmpInst::ICMP_SLT
: // X <s -1 -> false
2925 return getFalse(ITy
);
2927 case CmpInst::ICMP_ULE
: // X <=u 1 -> true
2928 case CmpInst::ICMP_SGE
: // X >=s -1 -> true
2929 return getTrue(ITy
);
2939 case ICmpInst::ICMP_UGE
:
2940 if (isImpliedCondition(RHS
, LHS
, Q
.DL
).value_or(false))
2941 return getTrue(ITy
);
2943 case ICmpInst::ICMP_SGE
:
2944 /// For signed comparison, the values for an i1 are 0 and -1
2945 /// respectively. This maps into a truth table of:
2946 /// LHS | RHS | LHS >=s RHS | LHS implies RHS
2947 /// 0 | 0 | 1 (0 >= 0) | 1
2948 /// 0 | 1 | 1 (0 >= -1) | 1
2949 /// 1 | 0 | 0 (-1 >= 0) | 0
2950 /// 1 | 1 | 1 (-1 >= -1) | 1
2951 if (isImpliedCondition(LHS
, RHS
, Q
.DL
).value_or(false))
2952 return getTrue(ITy
);
2954 case ICmpInst::ICMP_ULE
:
2955 if (isImpliedCondition(LHS
, RHS
, Q
.DL
).value_or(false))
2956 return getTrue(ITy
);
2958 case ICmpInst::ICMP_SLE
:
2959 /// SLE follows the same logic as SGE with the LHS and RHS swapped.
2960 if (isImpliedCondition(RHS
, LHS
, Q
.DL
).value_or(false))
2961 return getTrue(ITy
);
2968 /// Try hard to fold icmp with zero RHS because this is a common case.
2969 static Value
*simplifyICmpWithZero(CmpInst::Predicate Pred
, Value
*LHS
,
2970 Value
*RHS
, const SimplifyQuery
&Q
) {
2971 if (!match(RHS
, m_Zero()))
2974 Type
*ITy
= getCompareTy(LHS
); // The return type.
2977 llvm_unreachable("Unknown ICmp predicate!");
2978 case ICmpInst::ICMP_ULT
:
2979 return getFalse(ITy
);
2980 case ICmpInst::ICMP_UGE
:
2981 return getTrue(ITy
);
2982 case ICmpInst::ICMP_EQ
:
2983 case ICmpInst::ICMP_ULE
:
2984 if (isKnownNonZero(LHS
, Q
.DL
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
, Q
.IIQ
.UseInstrInfo
))
2985 return getFalse(ITy
);
2987 case ICmpInst::ICMP_NE
:
2988 case ICmpInst::ICMP_UGT
:
2989 if (isKnownNonZero(LHS
, Q
.DL
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
, Q
.IIQ
.UseInstrInfo
))
2990 return getTrue(ITy
);
2992 case ICmpInst::ICMP_SLT
: {
2993 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
2994 if (LHSKnown
.isNegative())
2995 return getTrue(ITy
);
2996 if (LHSKnown
.isNonNegative())
2997 return getFalse(ITy
);
3000 case ICmpInst::ICMP_SLE
: {
3001 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
3002 if (LHSKnown
.isNegative())
3003 return getTrue(ITy
);
3004 if (LHSKnown
.isNonNegative() &&
3005 isKnownNonZero(LHS
, Q
.DL
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
))
3006 return getFalse(ITy
);
3009 case ICmpInst::ICMP_SGE
: {
3010 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
3011 if (LHSKnown
.isNegative())
3012 return getFalse(ITy
);
3013 if (LHSKnown
.isNonNegative())
3014 return getTrue(ITy
);
3017 case ICmpInst::ICMP_SGT
: {
3018 KnownBits LHSKnown
= computeKnownBits(LHS
, /* Depth */ 0, Q
);
3019 if (LHSKnown
.isNegative())
3020 return getFalse(ITy
);
3021 if (LHSKnown
.isNonNegative() &&
3022 isKnownNonZero(LHS
, Q
.DL
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
))
3023 return getTrue(ITy
);
3031 static Value
*simplifyICmpWithConstant(CmpInst::Predicate Pred
, Value
*LHS
,
3032 Value
*RHS
, const InstrInfoQuery
&IIQ
) {
3033 Type
*ITy
= getCompareTy(RHS
); // The return type.
3036 // Sign-bit checks can be optimized to true/false after unsigned
3037 // floating-point casts:
3038 // icmp slt (bitcast (uitofp X)), 0 --> false
3039 // icmp sgt (bitcast (uitofp X)), -1 --> true
3040 if (match(LHS
, m_BitCast(m_UIToFP(m_Value(X
))))) {
3041 if (Pred
== ICmpInst::ICMP_SLT
&& match(RHS
, m_Zero()))
3042 return ConstantInt::getFalse(ITy
);
3043 if (Pred
== ICmpInst::ICMP_SGT
&& match(RHS
, m_AllOnes()))
3044 return ConstantInt::getTrue(ITy
);
3048 if (!match(RHS
, m_APIntAllowUndef(C
)))
3051 // Rule out tautological comparisons (eg., ult 0 or uge 0).
3052 ConstantRange RHS_CR
= ConstantRange::makeExactICmpRegion(Pred
, *C
);
3053 if (RHS_CR
.isEmptySet())
3054 return ConstantInt::getFalse(ITy
);
3055 if (RHS_CR
.isFullSet())
3056 return ConstantInt::getTrue(ITy
);
3058 ConstantRange LHS_CR
=
3059 computeConstantRange(LHS
, CmpInst::isSigned(Pred
), IIQ
.UseInstrInfo
);
3060 if (!LHS_CR
.isFullSet()) {
3061 if (RHS_CR
.contains(LHS_CR
))
3062 return ConstantInt::getTrue(ITy
);
3063 if (RHS_CR
.inverse().contains(LHS_CR
))
3064 return ConstantInt::getFalse(ITy
);
3067 // (mul nuw/nsw X, MulC) != C --> true (if C is not a multiple of MulC)
3068 // (mul nuw/nsw X, MulC) == C --> false (if C is not a multiple of MulC)
3070 if (IIQ
.UseInstrInfo
&& ICmpInst::isEquality(Pred
) &&
3071 ((match(LHS
, m_NUWMul(m_Value(), m_APIntAllowUndef(MulC
))) &&
3072 *MulC
!= 0 && C
->urem(*MulC
) != 0) ||
3073 (match(LHS
, m_NSWMul(m_Value(), m_APIntAllowUndef(MulC
))) &&
3074 *MulC
!= 0 && C
->srem(*MulC
) != 0)))
3075 return ConstantInt::get(ITy
, Pred
== ICmpInst::ICMP_NE
);
3080 static Value
*simplifyICmpWithBinOpOnLHS(CmpInst::Predicate Pred
,
3081 BinaryOperator
*LBO
, Value
*RHS
,
3082 const SimplifyQuery
&Q
,
3083 unsigned MaxRecurse
) {
3084 Type
*ITy
= getCompareTy(RHS
); // The return type.
3087 // icmp pred (or X, Y), X
3088 if (match(LBO
, m_c_Or(m_Value(Y
), m_Specific(RHS
)))) {
3089 if (Pred
== ICmpInst::ICMP_ULT
)
3090 return getFalse(ITy
);
3091 if (Pred
== ICmpInst::ICMP_UGE
)
3092 return getTrue(ITy
);
3094 if (Pred
== ICmpInst::ICMP_SLT
|| Pred
== ICmpInst::ICMP_SGE
) {
3095 KnownBits RHSKnown
= computeKnownBits(RHS
, /* Depth */ 0, Q
);
3096 KnownBits YKnown
= computeKnownBits(Y
, /* Depth */ 0, Q
);
3097 if (RHSKnown
.isNonNegative() && YKnown
.isNegative())
3098 return Pred
== ICmpInst::ICMP_SLT
? getTrue(ITy
) : getFalse(ITy
);
3099 if (RHSKnown
.isNegative() || YKnown
.isNonNegative())
3100 return Pred
== ICmpInst::ICMP_SLT
? getFalse(ITy
) : getTrue(ITy
);
3104 // icmp pred (and X, Y), X
3105 if (match(LBO
, m_c_And(m_Value(), m_Specific(RHS
)))) {
3106 if (Pred
== ICmpInst::ICMP_UGT
)
3107 return getFalse(ITy
);
3108 if (Pred
== ICmpInst::ICMP_ULE
)
3109 return getTrue(ITy
);
3112 // icmp pred (urem X, Y), Y
3113 if (match(LBO
, m_URem(m_Value(), m_Specific(RHS
)))) {
3117 case ICmpInst::ICMP_SGT
:
3118 case ICmpInst::ICMP_SGE
: {
3119 KnownBits Known
= computeKnownBits(RHS
, /* Depth */ 0, Q
);
3120 if (!Known
.isNonNegative())
3124 case ICmpInst::ICMP_EQ
:
3125 case ICmpInst::ICMP_UGT
:
3126 case ICmpInst::ICMP_UGE
:
3127 return getFalse(ITy
);
3128 case ICmpInst::ICMP_SLT
:
3129 case ICmpInst::ICMP_SLE
: {
3130 KnownBits Known
= computeKnownBits(RHS
, /* Depth */ 0, Q
);
3131 if (!Known
.isNonNegative())
3135 case ICmpInst::ICMP_NE
:
3136 case ICmpInst::ICMP_ULT
:
3137 case ICmpInst::ICMP_ULE
:
3138 return getTrue(ITy
);
3142 // icmp pred (urem X, Y), X
3143 if (match(LBO
, m_URem(m_Specific(RHS
), m_Value()))) {
3144 if (Pred
== ICmpInst::ICMP_ULE
)
3145 return getTrue(ITy
);
3146 if (Pred
== ICmpInst::ICMP_UGT
)
3147 return getFalse(ITy
);
3150 // x >>u y <=u x --> true.
3151 // x >>u y >u x --> false.
3152 // x udiv y <=u x --> true.
3153 // x udiv y >u x --> false.
3154 if (match(LBO
, m_LShr(m_Specific(RHS
), m_Value())) ||
3155 match(LBO
, m_UDiv(m_Specific(RHS
), m_Value()))) {
3156 // icmp pred (X op Y), X
3157 if (Pred
== ICmpInst::ICMP_UGT
)
3158 return getFalse(ITy
);
3159 if (Pred
== ICmpInst::ICMP_ULE
)
3160 return getTrue(ITy
);
3164 // x >>u C <u x --> true for C != 0.
3165 // x >>u C != x --> true for C != 0.
3166 // x >>u C >=u x --> false for C != 0.
3167 // x >>u C == x --> false for C != 0.
3168 // x udiv C <u x --> true for C != 1.
3169 // x udiv C != x --> true for C != 1.
3170 // x udiv C >=u x --> false for C != 1.
3171 // x udiv C == x --> false for C != 1.
3172 // TODO: allow non-constant shift amount/divisor
3174 if ((match(LBO
, m_LShr(m_Specific(RHS
), m_APInt(C
))) && *C
!= 0) ||
3175 (match(LBO
, m_UDiv(m_Specific(RHS
), m_APInt(C
))) && *C
!= 1)) {
3176 if (isKnownNonZero(RHS
, Q
.DL
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
)) {
3180 case ICmpInst::ICMP_EQ
:
3181 case ICmpInst::ICMP_UGE
:
3182 return getFalse(ITy
);
3183 case ICmpInst::ICMP_NE
:
3184 case ICmpInst::ICMP_ULT
:
3185 return getTrue(ITy
);
3186 case ICmpInst::ICMP_UGT
:
3187 case ICmpInst::ICMP_ULE
:
3188 // UGT/ULE are handled by the more general case just above
3189 llvm_unreachable("Unexpected UGT/ULE, should have been handled");
3194 // (x*C1)/C2 <= x for C1 <= C2.
3195 // This holds even if the multiplication overflows: Assume that x != 0 and
3196 // arithmetic is modulo M. For overflow to occur we must have C1 >= M/x and
3197 // thus C2 >= M/x. It follows that (x*C1)/C2 <= (M-1)/C2 <= ((M-1)*x)/M < x.
3199 // Additionally, either the multiplication and division might be represented
3201 // (x*C1)>>C2 <= x for C1 < 2**C2.
3202 // (x<<C1)/C2 <= x for 2**C1 < C2.
3203 const APInt
*C1
, *C2
;
3204 if ((match(LBO
, m_UDiv(m_Mul(m_Specific(RHS
), m_APInt(C1
)), m_APInt(C2
))) &&
3206 (match(LBO
, m_LShr(m_Mul(m_Specific(RHS
), m_APInt(C1
)), m_APInt(C2
))) &&
3207 C1
->ule(APInt(C2
->getBitWidth(), 1) << *C2
)) ||
3208 (match(LBO
, m_UDiv(m_Shl(m_Specific(RHS
), m_APInt(C1
)), m_APInt(C2
))) &&
3209 (APInt(C1
->getBitWidth(), 1) << *C1
).ule(*C2
))) {
3210 if (Pred
== ICmpInst::ICMP_UGT
)
3211 return getFalse(ITy
);
3212 if (Pred
== ICmpInst::ICMP_ULE
)
3213 return getTrue(ITy
);
3216 // (sub C, X) == X, C is odd --> false
3217 // (sub C, X) != X, C is odd --> true
3218 if (match(LBO
, m_Sub(m_APIntAllowUndef(C
), m_Specific(RHS
))) &&
3219 (*C
& 1) == 1 && ICmpInst::isEquality(Pred
))
3220 return (Pred
== ICmpInst::ICMP_EQ
) ? getFalse(ITy
) : getTrue(ITy
);
3225 // If only one of the icmp's operands has NSW flags, try to prove that:
3227 // icmp slt (x + C1), (x +nsw C2)
3229 // is equivalent to:
3233 // which is true if x + C2 has the NSW flags set and:
3234 // *) C1 < C2 && C1 >= 0, or
3235 // *) C2 < C1 && C1 <= 0.
3237 static bool trySimplifyICmpWithAdds(CmpInst::Predicate Pred
, Value
*LHS
,
3238 Value
*RHS
, const InstrInfoQuery
&IIQ
) {
3239 // TODO: only support icmp slt for now.
3240 if (Pred
!= CmpInst::ICMP_SLT
|| !IIQ
.UseInstrInfo
)
3243 // Canonicalize nsw add as RHS.
3244 if (!match(RHS
, m_NSWAdd(m_Value(), m_Value())))
3245 std::swap(LHS
, RHS
);
3246 if (!match(RHS
, m_NSWAdd(m_Value(), m_Value())))
3250 const APInt
*C1
, *C2
;
3251 if (!match(LHS
, m_c_Add(m_Value(X
), m_APInt(C1
))) ||
3252 !match(RHS
, m_c_Add(m_Specific(X
), m_APInt(C2
))))
3255 return (C1
->slt(*C2
) && C1
->isNonNegative()) ||
3256 (C2
->slt(*C1
) && C1
->isNonPositive());
3259 /// TODO: A large part of this logic is duplicated in InstCombine's
3260 /// foldICmpBinOp(). We should be able to share that and avoid the code
3262 static Value
*simplifyICmpWithBinOp(CmpInst::Predicate Pred
, Value
*LHS
,
3263 Value
*RHS
, const SimplifyQuery
&Q
,
3264 unsigned MaxRecurse
) {
3265 BinaryOperator
*LBO
= dyn_cast
<BinaryOperator
>(LHS
);
3266 BinaryOperator
*RBO
= dyn_cast
<BinaryOperator
>(RHS
);
3267 if (MaxRecurse
&& (LBO
|| RBO
)) {
3268 // Analyze the case when either LHS or RHS is an add instruction.
3269 Value
*A
= nullptr, *B
= nullptr, *C
= nullptr, *D
= nullptr;
3270 // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
3271 bool NoLHSWrapProblem
= false, NoRHSWrapProblem
= false;
3272 if (LBO
&& LBO
->getOpcode() == Instruction::Add
) {
3273 A
= LBO
->getOperand(0);
3274 B
= LBO
->getOperand(1);
3276 ICmpInst::isEquality(Pred
) ||
3277 (CmpInst::isUnsigned(Pred
) &&
3278 Q
.IIQ
.hasNoUnsignedWrap(cast
<OverflowingBinaryOperator
>(LBO
))) ||
3279 (CmpInst::isSigned(Pred
) &&
3280 Q
.IIQ
.hasNoSignedWrap(cast
<OverflowingBinaryOperator
>(LBO
)));
3282 if (RBO
&& RBO
->getOpcode() == Instruction::Add
) {
3283 C
= RBO
->getOperand(0);
3284 D
= RBO
->getOperand(1);
3286 ICmpInst::isEquality(Pred
) ||
3287 (CmpInst::isUnsigned(Pred
) &&
3288 Q
.IIQ
.hasNoUnsignedWrap(cast
<OverflowingBinaryOperator
>(RBO
))) ||
3289 (CmpInst::isSigned(Pred
) &&
3290 Q
.IIQ
.hasNoSignedWrap(cast
<OverflowingBinaryOperator
>(RBO
)));
3293 // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
3294 if ((A
== RHS
|| B
== RHS
) && NoLHSWrapProblem
)
3295 if (Value
*V
= simplifyICmpInst(Pred
, A
== RHS
? B
: A
,
3296 Constant::getNullValue(RHS
->getType()), Q
,
3300 // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
3301 if ((C
== LHS
|| D
== LHS
) && NoRHSWrapProblem
)
3303 simplifyICmpInst(Pred
, Constant::getNullValue(LHS
->getType()),
3304 C
== LHS
? D
: C
, Q
, MaxRecurse
- 1))
3307 // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
3308 bool CanSimplify
= (NoLHSWrapProblem
&& NoRHSWrapProblem
) ||
3309 trySimplifyICmpWithAdds(Pred
, LHS
, RHS
, Q
.IIQ
);
3310 if (A
&& C
&& (A
== C
|| A
== D
|| B
== C
|| B
== D
) && CanSimplify
) {
3311 // Determine Y and Z in the form icmp (X+Y), (X+Z).
3314 // C + B == C + D -> B == D
3317 } else if (A
== D
) {
3318 // D + B == C + D -> B == C
3321 } else if (B
== C
) {
3322 // A + C == C + D -> A == D
3327 // A + D == C + D -> A == C
3331 if (Value
*V
= simplifyICmpInst(Pred
, Y
, Z
, Q
, MaxRecurse
- 1))
3337 if (Value
*V
= simplifyICmpWithBinOpOnLHS(Pred
, LBO
, RHS
, Q
, MaxRecurse
))
3341 if (Value
*V
= simplifyICmpWithBinOpOnLHS(
3342 ICmpInst::getSwappedPredicate(Pred
), RBO
, LHS
, Q
, MaxRecurse
))
3345 // 0 - (zext X) pred C
3346 if (!CmpInst::isUnsigned(Pred
) && match(LHS
, m_Neg(m_ZExt(m_Value())))) {
3348 if (match(RHS
, m_APInt(C
))) {
3349 if (C
->isStrictlyPositive()) {
3350 if (Pred
== ICmpInst::ICMP_SLT
|| Pred
== ICmpInst::ICMP_NE
)
3351 return ConstantInt::getTrue(getCompareTy(RHS
));
3352 if (Pred
== ICmpInst::ICMP_SGE
|| Pred
== ICmpInst::ICMP_EQ
)
3353 return ConstantInt::getFalse(getCompareTy(RHS
));
3355 if (C
->isNonNegative()) {
3356 if (Pred
== ICmpInst::ICMP_SLE
)
3357 return ConstantInt::getTrue(getCompareTy(RHS
));
3358 if (Pred
== ICmpInst::ICMP_SGT
)
3359 return ConstantInt::getFalse(getCompareTy(RHS
));
3364 // If C2 is a power-of-2 and C is not:
3365 // (C2 << X) == C --> false
3366 // (C2 << X) != C --> true
3368 if (match(LHS
, m_Shl(m_Power2(), m_Value())) &&
3369 match(RHS
, m_APIntAllowUndef(C
)) && !C
->isPowerOf2()) {
3370 // C2 << X can equal zero in some circumstances.
3371 // This simplification might be unsafe if C is zero.
3373 // We know it is safe if:
3374 // - The shift is nsw. We can't shift out the one bit.
3375 // - The shift is nuw. We can't shift out the one bit.
3378 if (Q
.IIQ
.hasNoSignedWrap(cast
<OverflowingBinaryOperator
>(LBO
)) ||
3379 Q
.IIQ
.hasNoUnsignedWrap(cast
<OverflowingBinaryOperator
>(LBO
)) ||
3380 match(LHS
, m_Shl(m_One(), m_Value())) || !C
->isZero()) {
3381 if (Pred
== ICmpInst::ICMP_EQ
)
3382 return ConstantInt::getFalse(getCompareTy(RHS
));
3383 if (Pred
== ICmpInst::ICMP_NE
)
3384 return ConstantInt::getTrue(getCompareTy(RHS
));
3388 // If C is a power-of-2:
3389 // (C << X) >u 0x8000 --> false
3390 // (C << X) <=u 0x8000 --> true
3391 if (match(LHS
, m_Shl(m_Power2(), m_Value())) && match(RHS
, m_SignMask())) {
3392 if (Pred
== ICmpInst::ICMP_UGT
)
3393 return ConstantInt::getFalse(getCompareTy(RHS
));
3394 if (Pred
== ICmpInst::ICMP_ULE
)
3395 return ConstantInt::getTrue(getCompareTy(RHS
));
3398 if (!MaxRecurse
|| !LBO
|| !RBO
|| LBO
->getOpcode() != RBO
->getOpcode())
3401 if (LBO
->getOperand(0) == RBO
->getOperand(0)) {
3402 switch (LBO
->getOpcode()) {
3405 case Instruction::Shl
: {
3406 bool NUW
= Q
.IIQ
.hasNoUnsignedWrap(LBO
) && Q
.IIQ
.hasNoUnsignedWrap(RBO
);
3407 bool NSW
= Q
.IIQ
.hasNoSignedWrap(LBO
) && Q
.IIQ
.hasNoSignedWrap(RBO
);
3408 if (!NUW
|| (ICmpInst::isSigned(Pred
) && !NSW
) ||
3409 !isKnownNonZero(LBO
->getOperand(0), Q
.DL
))
3411 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(1),
3412 RBO
->getOperand(1), Q
, MaxRecurse
- 1))
3416 // If C1 & C2 == C1, A = X and/or C1, B = X and/or C2:
3417 // icmp ule A, B -> true
3418 // icmp ugt A, B -> false
3419 // icmp sle A, B -> true (C1 and C2 are the same sign)
3420 // icmp sgt A, B -> false (C1 and C2 are the same sign)
3421 case Instruction::And
:
3422 case Instruction::Or
: {
3423 const APInt
*C1
, *C2
;
3424 if (ICmpInst::isRelational(Pred
) &&
3425 match(LBO
->getOperand(1), m_APInt(C1
)) &&
3426 match(RBO
->getOperand(1), m_APInt(C2
))) {
3427 if (!C1
->isSubsetOf(*C2
)) {
3429 Pred
= ICmpInst::getSwappedPredicate(Pred
);
3431 if (C1
->isSubsetOf(*C2
)) {
3432 if (Pred
== ICmpInst::ICMP_ULE
)
3433 return ConstantInt::getTrue(getCompareTy(LHS
));
3434 if (Pred
== ICmpInst::ICMP_UGT
)
3435 return ConstantInt::getFalse(getCompareTy(LHS
));
3436 if (C1
->isNonNegative() == C2
->isNonNegative()) {
3437 if (Pred
== ICmpInst::ICMP_SLE
)
3438 return ConstantInt::getTrue(getCompareTy(LHS
));
3439 if (Pred
== ICmpInst::ICMP_SGT
)
3440 return ConstantInt::getFalse(getCompareTy(LHS
));
3449 if (LBO
->getOperand(1) == RBO
->getOperand(1)) {
3450 switch (LBO
->getOpcode()) {
3453 case Instruction::UDiv
:
3454 case Instruction::LShr
:
3455 if (ICmpInst::isSigned(Pred
) || !Q
.IIQ
.isExact(LBO
) ||
3456 !Q
.IIQ
.isExact(RBO
))
3458 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3459 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3462 case Instruction::SDiv
:
3463 if (!ICmpInst::isEquality(Pred
) || !Q
.IIQ
.isExact(LBO
) ||
3464 !Q
.IIQ
.isExact(RBO
))
3466 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3467 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3470 case Instruction::AShr
:
3471 if (!Q
.IIQ
.isExact(LBO
) || !Q
.IIQ
.isExact(RBO
))
3473 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3474 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3477 case Instruction::Shl
: {
3478 bool NUW
= Q
.IIQ
.hasNoUnsignedWrap(LBO
) && Q
.IIQ
.hasNoUnsignedWrap(RBO
);
3479 bool NSW
= Q
.IIQ
.hasNoSignedWrap(LBO
) && Q
.IIQ
.hasNoSignedWrap(RBO
);
3482 if (!NSW
&& ICmpInst::isSigned(Pred
))
3484 if (Value
*V
= simplifyICmpInst(Pred
, LBO
->getOperand(0),
3485 RBO
->getOperand(0), Q
, MaxRecurse
- 1))
3494 /// simplify integer comparisons where at least one operand of the compare
3495 /// matches an integer min/max idiom.
3496 static Value
*simplifyICmpWithMinMax(CmpInst::Predicate Pred
, Value
*LHS
,
3497 Value
*RHS
, const SimplifyQuery
&Q
,
3498 unsigned MaxRecurse
) {
3499 Type
*ITy
= getCompareTy(LHS
); // The return type.
3501 CmpInst::Predicate P
= CmpInst::BAD_ICMP_PREDICATE
;
3502 CmpInst::Predicate EqP
; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
3504 // Signed variants on "max(a,b)>=a -> true".
3505 if (match(LHS
, m_SMax(m_Value(A
), m_Value(B
))) && (A
== RHS
|| B
== RHS
)) {
3507 std::swap(A
, B
); // smax(A, B) pred A.
3508 EqP
= CmpInst::ICMP_SGE
; // "A == smax(A, B)" iff "A sge B".
3509 // We analyze this as smax(A, B) pred A.
3511 } else if (match(RHS
, m_SMax(m_Value(A
), m_Value(B
))) &&
3512 (A
== LHS
|| B
== LHS
)) {
3514 std::swap(A
, B
); // A pred smax(A, B).
3515 EqP
= CmpInst::ICMP_SGE
; // "A == smax(A, B)" iff "A sge B".
3516 // We analyze this as smax(A, B) swapped-pred A.
3517 P
= CmpInst::getSwappedPredicate(Pred
);
3518 } else if (match(LHS
, m_SMin(m_Value(A
), m_Value(B
))) &&
3519 (A
== RHS
|| B
== RHS
)) {
3521 std::swap(A
, B
); // smin(A, B) pred A.
3522 EqP
= CmpInst::ICMP_SLE
; // "A == smin(A, B)" iff "A sle B".
3523 // We analyze this as smax(-A, -B) swapped-pred -A.
3524 // Note that we do not need to actually form -A or -B thanks to EqP.
3525 P
= CmpInst::getSwappedPredicate(Pred
);
3526 } else if (match(RHS
, m_SMin(m_Value(A
), m_Value(B
))) &&
3527 (A
== LHS
|| B
== LHS
)) {
3529 std::swap(A
, B
); // A pred smin(A, B).
3530 EqP
= CmpInst::ICMP_SLE
; // "A == smin(A, B)" iff "A sle B".
3531 // We analyze this as smax(-A, -B) pred -A.
3532 // Note that we do not need to actually form -A or -B thanks to EqP.
3535 if (P
!= CmpInst::BAD_ICMP_PREDICATE
) {
3536 // Cases correspond to "max(A, B) p A".
3540 case CmpInst::ICMP_EQ
:
3541 case CmpInst::ICMP_SLE
:
3542 // Equivalent to "A EqP B". This may be the same as the condition tested
3543 // in the max/min; if so, we can just return that.
3544 if (Value
*V
= extractEquivalentCondition(LHS
, EqP
, A
, B
))
3546 if (Value
*V
= extractEquivalentCondition(RHS
, EqP
, A
, B
))
3548 // Otherwise, see if "A EqP B" simplifies.
3550 if (Value
*V
= simplifyICmpInst(EqP
, A
, B
, Q
, MaxRecurse
- 1))
3553 case CmpInst::ICMP_NE
:
3554 case CmpInst::ICMP_SGT
: {
3555 CmpInst::Predicate InvEqP
= CmpInst::getInversePredicate(EqP
);
3556 // Equivalent to "A InvEqP B". This may be the same as the condition
3557 // tested in the max/min; if so, we can just return that.
3558 if (Value
*V
= extractEquivalentCondition(LHS
, InvEqP
, A
, B
))
3560 if (Value
*V
= extractEquivalentCondition(RHS
, InvEqP
, A
, B
))
3562 // Otherwise, see if "A InvEqP B" simplifies.
3564 if (Value
*V
= simplifyICmpInst(InvEqP
, A
, B
, Q
, MaxRecurse
- 1))
3568 case CmpInst::ICMP_SGE
:
3570 return getTrue(ITy
);
3571 case CmpInst::ICMP_SLT
:
3573 return getFalse(ITy
);
3577 // Unsigned variants on "max(a,b)>=a -> true".
3578 P
= CmpInst::BAD_ICMP_PREDICATE
;
3579 if (match(LHS
, m_UMax(m_Value(A
), m_Value(B
))) && (A
== RHS
|| B
== RHS
)) {
3581 std::swap(A
, B
); // umax(A, B) pred A.
3582 EqP
= CmpInst::ICMP_UGE
; // "A == umax(A, B)" iff "A uge B".
3583 // We analyze this as umax(A, B) pred A.
3585 } else if (match(RHS
, m_UMax(m_Value(A
), m_Value(B
))) &&
3586 (A
== LHS
|| B
== LHS
)) {
3588 std::swap(A
, B
); // A pred umax(A, B).
3589 EqP
= CmpInst::ICMP_UGE
; // "A == umax(A, B)" iff "A uge B".
3590 // We analyze this as umax(A, B) swapped-pred A.
3591 P
= CmpInst::getSwappedPredicate(Pred
);
3592 } else if (match(LHS
, m_UMin(m_Value(A
), m_Value(B
))) &&
3593 (A
== RHS
|| B
== RHS
)) {
3595 std::swap(A
, B
); // umin(A, B) pred A.
3596 EqP
= CmpInst::ICMP_ULE
; // "A == umin(A, B)" iff "A ule B".
3597 // We analyze this as umax(-A, -B) swapped-pred -A.
3598 // Note that we do not need to actually form -A or -B thanks to EqP.
3599 P
= CmpInst::getSwappedPredicate(Pred
);
3600 } else if (match(RHS
, m_UMin(m_Value(A
), m_Value(B
))) &&
3601 (A
== LHS
|| B
== LHS
)) {
3603 std::swap(A
, B
); // A pred umin(A, B).
3604 EqP
= CmpInst::ICMP_ULE
; // "A == umin(A, B)" iff "A ule B".
3605 // We analyze this as umax(-A, -B) pred -A.
3606 // Note that we do not need to actually form -A or -B thanks to EqP.
3609 if (P
!= CmpInst::BAD_ICMP_PREDICATE
) {
3610 // Cases correspond to "max(A, B) p A".
3614 case CmpInst::ICMP_EQ
:
3615 case CmpInst::ICMP_ULE
:
3616 // Equivalent to "A EqP B". This may be the same as the condition tested
3617 // in the max/min; if so, we can just return that.
3618 if (Value
*V
= extractEquivalentCondition(LHS
, EqP
, A
, B
))
3620 if (Value
*V
= extractEquivalentCondition(RHS
, EqP
, A
, B
))
3622 // Otherwise, see if "A EqP B" simplifies.
3624 if (Value
*V
= simplifyICmpInst(EqP
, A
, B
, Q
, MaxRecurse
- 1))
3627 case CmpInst::ICMP_NE
:
3628 case CmpInst::ICMP_UGT
: {
3629 CmpInst::Predicate InvEqP
= CmpInst::getInversePredicate(EqP
);
3630 // Equivalent to "A InvEqP B". This may be the same as the condition
3631 // tested in the max/min; if so, we can just return that.
3632 if (Value
*V
= extractEquivalentCondition(LHS
, InvEqP
, A
, B
))
3634 if (Value
*V
= extractEquivalentCondition(RHS
, InvEqP
, A
, B
))
3636 // Otherwise, see if "A InvEqP B" simplifies.
3638 if (Value
*V
= simplifyICmpInst(InvEqP
, A
, B
, Q
, MaxRecurse
- 1))
3642 case CmpInst::ICMP_UGE
:
3643 return getTrue(ITy
);
3644 case CmpInst::ICMP_ULT
:
3645 return getFalse(ITy
);
3649 // Comparing 1 each of min/max with a common operand?
3650 // Canonicalize min operand to RHS.
3651 if (match(LHS
, m_UMin(m_Value(), m_Value())) ||
3652 match(LHS
, m_SMin(m_Value(), m_Value()))) {
3653 std::swap(LHS
, RHS
);
3654 Pred
= ICmpInst::getSwappedPredicate(Pred
);
3658 if (match(LHS
, m_SMax(m_Value(A
), m_Value(B
))) &&
3659 match(RHS
, m_SMin(m_Value(C
), m_Value(D
))) &&
3660 (A
== C
|| A
== D
|| B
== C
|| B
== D
)) {
3661 // smax(A, B) >=s smin(A, D) --> true
3662 if (Pred
== CmpInst::ICMP_SGE
)
3663 return getTrue(ITy
);
3664 // smax(A, B) <s smin(A, D) --> false
3665 if (Pred
== CmpInst::ICMP_SLT
)
3666 return getFalse(ITy
);
3667 } else if (match(LHS
, m_UMax(m_Value(A
), m_Value(B
))) &&
3668 match(RHS
, m_UMin(m_Value(C
), m_Value(D
))) &&
3669 (A
== C
|| A
== D
|| B
== C
|| B
== D
)) {
3670 // umax(A, B) >=u umin(A, D) --> true
3671 if (Pred
== CmpInst::ICMP_UGE
)
3672 return getTrue(ITy
);
3673 // umax(A, B) <u umin(A, D) --> false
3674 if (Pred
== CmpInst::ICMP_ULT
)
3675 return getFalse(ITy
);
3681 static Value
*simplifyICmpWithDominatingAssume(CmpInst::Predicate Predicate
,
3682 Value
*LHS
, Value
*RHS
,
3683 const SimplifyQuery
&Q
) {
3684 // Gracefully handle instructions that have not been inserted yet.
3685 if (!Q
.AC
|| !Q
.CxtI
)
3688 for (Value
*AssumeBaseOp
: {LHS
, RHS
}) {
3689 for (auto &AssumeVH
: Q
.AC
->assumptionsFor(AssumeBaseOp
)) {
3693 CallInst
*Assume
= cast
<CallInst
>(AssumeVH
);
3694 if (std::optional
<bool> Imp
= isImpliedCondition(
3695 Assume
->getArgOperand(0), Predicate
, LHS
, RHS
, Q
.DL
))
3696 if (isValidAssumeForContext(Assume
, Q
.CxtI
, Q
.DT
))
3697 return ConstantInt::get(getCompareTy(LHS
), *Imp
);
3704 static Value
*simplifyICmpWithIntrinsicOnLHS(CmpInst::Predicate Pred
,
3705 Value
*LHS
, Value
*RHS
) {
3706 auto *II
= dyn_cast
<IntrinsicInst
>(LHS
);
3710 switch (II
->getIntrinsicID()) {
3711 case Intrinsic::uadd_sat
:
3712 // uadd.sat(X, Y) uge X, uadd.sat(X, Y) uge Y
3713 if (II
->getArgOperand(0) == RHS
|| II
->getArgOperand(1) == RHS
) {
3714 if (Pred
== ICmpInst::ICMP_UGE
)
3715 return ConstantInt::getTrue(getCompareTy(II
));
3716 if (Pred
== ICmpInst::ICMP_ULT
)
3717 return ConstantInt::getFalse(getCompareTy(II
));
3720 case Intrinsic::usub_sat
:
3721 // usub.sat(X, Y) ule X
3722 if (II
->getArgOperand(0) == RHS
) {
3723 if (Pred
== ICmpInst::ICMP_ULE
)
3724 return ConstantInt::getTrue(getCompareTy(II
));
3725 if (Pred
== ICmpInst::ICMP_UGT
)
3726 return ConstantInt::getFalse(getCompareTy(II
));
3734 /// Given operands for an ICmpInst, see if we can fold the result.
3735 /// If not, this returns null.
3736 static Value
*simplifyICmpInst(unsigned Predicate
, Value
*LHS
, Value
*RHS
,
3737 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
3738 CmpInst::Predicate Pred
= (CmpInst::Predicate
)Predicate
;
3739 assert(CmpInst::isIntPredicate(Pred
) && "Not an integer compare!");
3741 if (Constant
*CLHS
= dyn_cast
<Constant
>(LHS
)) {
3742 if (Constant
*CRHS
= dyn_cast
<Constant
>(RHS
))
3743 return ConstantFoldCompareInstOperands(Pred
, CLHS
, CRHS
, Q
.DL
, Q
.TLI
);
3745 // If we have a constant, make sure it is on the RHS.
3746 std::swap(LHS
, RHS
);
3747 Pred
= CmpInst::getSwappedPredicate(Pred
);
3749 assert(!isa
<UndefValue
>(LHS
) && "Unexpected icmp undef,%X");
3751 Type
*ITy
= getCompareTy(LHS
); // The return type.
3753 // icmp poison, X -> poison
3754 if (isa
<PoisonValue
>(RHS
))
3755 return PoisonValue::get(ITy
);
3757 // For EQ and NE, we can always pick a value for the undef to make the
3758 // predicate pass or fail, so we can return undef.
3759 // Matches behavior in llvm::ConstantFoldCompareInstruction.
3760 if (Q
.isUndefValue(RHS
) && ICmpInst::isEquality(Pred
))
3761 return UndefValue::get(ITy
);
3763 // icmp X, X -> true/false
3764 // icmp X, undef -> true/false because undef could be X.
3765 if (LHS
== RHS
|| Q
.isUndefValue(RHS
))
3766 return ConstantInt::get(ITy
, CmpInst::isTrueWhenEqual(Pred
));
3768 if (Value
*V
= simplifyICmpOfBools(Pred
, LHS
, RHS
, Q
))
3771 // TODO: Sink/common this with other potentially expensive calls that use
3772 // ValueTracking? See comment below for isKnownNonEqual().
3773 if (Value
*V
= simplifyICmpWithZero(Pred
, LHS
, RHS
, Q
))
3776 if (Value
*V
= simplifyICmpWithConstant(Pred
, LHS
, RHS
, Q
.IIQ
))
3779 // If both operands have range metadata, use the metadata
3780 // to simplify the comparison.
3781 if (isa
<Instruction
>(RHS
) && isa
<Instruction
>(LHS
)) {
3782 auto RHS_Instr
= cast
<Instruction
>(RHS
);
3783 auto LHS_Instr
= cast
<Instruction
>(LHS
);
3785 if (Q
.IIQ
.getMetadata(RHS_Instr
, LLVMContext::MD_range
) &&
3786 Q
.IIQ
.getMetadata(LHS_Instr
, LLVMContext::MD_range
)) {
3787 auto RHS_CR
= getConstantRangeFromMetadata(
3788 *RHS_Instr
->getMetadata(LLVMContext::MD_range
));
3789 auto LHS_CR
= getConstantRangeFromMetadata(
3790 *LHS_Instr
->getMetadata(LLVMContext::MD_range
));
3792 if (LHS_CR
.icmp(Pred
, RHS_CR
))
3793 return ConstantInt::getTrue(RHS
->getContext());
3795 if (LHS_CR
.icmp(CmpInst::getInversePredicate(Pred
), RHS_CR
))
3796 return ConstantInt::getFalse(RHS
->getContext());
3800 // Compare of cast, for example (zext X) != 0 -> X != 0
3801 if (isa
<CastInst
>(LHS
) && (isa
<Constant
>(RHS
) || isa
<CastInst
>(RHS
))) {
3802 Instruction
*LI
= cast
<CastInst
>(LHS
);
3803 Value
*SrcOp
= LI
->getOperand(0);
3804 Type
*SrcTy
= SrcOp
->getType();
3805 Type
*DstTy
= LI
->getType();
3807 // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
3808 // if the integer type is the same size as the pointer type.
3809 if (MaxRecurse
&& isa
<PtrToIntInst
>(LI
) &&
3810 Q
.DL
.getTypeSizeInBits(SrcTy
) == DstTy
->getPrimitiveSizeInBits()) {
3811 if (Constant
*RHSC
= dyn_cast
<Constant
>(RHS
)) {
3812 // Transfer the cast to the constant.
3813 if (Value
*V
= simplifyICmpInst(Pred
, SrcOp
,
3814 ConstantExpr::getIntToPtr(RHSC
, SrcTy
),
3817 } else if (PtrToIntInst
*RI
= dyn_cast
<PtrToIntInst
>(RHS
)) {
3818 if (RI
->getOperand(0)->getType() == SrcTy
)
3819 // Compare without the cast.
3820 if (Value
*V
= simplifyICmpInst(Pred
, SrcOp
, RI
->getOperand(0), Q
,
3826 if (isa
<ZExtInst
>(LHS
)) {
3827 // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
3829 if (ZExtInst
*RI
= dyn_cast
<ZExtInst
>(RHS
)) {
3830 if (MaxRecurse
&& SrcTy
== RI
->getOperand(0)->getType())
3831 // Compare X and Y. Note that signed predicates become unsigned.
3833 simplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred
), SrcOp
,
3834 RI
->getOperand(0), Q
, MaxRecurse
- 1))
3837 // Fold (zext X) ule (sext X), (zext X) sge (sext X) to true.
3838 else if (SExtInst
*RI
= dyn_cast
<SExtInst
>(RHS
)) {
3839 if (SrcOp
== RI
->getOperand(0)) {
3840 if (Pred
== ICmpInst::ICMP_ULE
|| Pred
== ICmpInst::ICMP_SGE
)
3841 return ConstantInt::getTrue(ITy
);
3842 if (Pred
== ICmpInst::ICMP_UGT
|| Pred
== ICmpInst::ICMP_SLT
)
3843 return ConstantInt::getFalse(ITy
);
3846 // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
3847 // too. If not, then try to deduce the result of the comparison.
3848 else if (match(RHS
, m_ImmConstant())) {
3849 Constant
*C
= dyn_cast
<Constant
>(RHS
);
3850 assert(C
!= nullptr);
3852 // Compute the constant that would happen if we truncated to SrcTy then
3853 // reextended to DstTy.
3855 ConstantFoldCastOperand(Instruction::Trunc
, C
, SrcTy
, Q
.DL
);
3856 assert(Trunc
&& "Constant-fold of ImmConstant should not fail");
3858 ConstantFoldCastOperand(CastInst::ZExt
, Trunc
, DstTy
, Q
.DL
);
3859 assert(RExt
&& "Constant-fold of ImmConstant should not fail");
3861 ConstantFoldCompareInstOperands(ICmpInst::ICMP_EQ
, RExt
, C
, Q
.DL
);
3862 assert(AnyEq
&& "Constant-fold of ImmConstant should not fail");
3864 // If the re-extended constant didn't change any of the elements then
3865 // this is effectively also a case of comparing two zero-extended
3867 if (AnyEq
->isAllOnesValue() && MaxRecurse
)
3868 if (Value
*V
= simplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred
),
3869 SrcOp
, Trunc
, Q
, MaxRecurse
- 1))
3872 // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
3873 // there. Use this to work out the result of the comparison.
3874 if (AnyEq
->isNullValue()) {
3877 llvm_unreachable("Unknown ICmp predicate!");
3879 case ICmpInst::ICMP_EQ
:
3880 case ICmpInst::ICMP_UGT
:
3881 case ICmpInst::ICMP_UGE
:
3882 return Constant::getNullValue(ITy
);
3884 case ICmpInst::ICMP_NE
:
3885 case ICmpInst::ICMP_ULT
:
3886 case ICmpInst::ICMP_ULE
:
3887 return Constant::getAllOnesValue(ITy
);
3889 // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
3890 // is non-negative then LHS <s RHS.
3891 case ICmpInst::ICMP_SGT
:
3892 case ICmpInst::ICMP_SGE
:
3893 return ConstantFoldCompareInstOperands(
3894 ICmpInst::ICMP_SLT
, C
, Constant::getNullValue(C
->getType()),
3896 case ICmpInst::ICMP_SLT
:
3897 case ICmpInst::ICMP_SLE
:
3898 return ConstantFoldCompareInstOperands(
3899 ICmpInst::ICMP_SGE
, C
, Constant::getNullValue(C
->getType()),
3906 if (isa
<SExtInst
>(LHS
)) {
3907 // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
3909 if (SExtInst
*RI
= dyn_cast
<SExtInst
>(RHS
)) {
3910 if (MaxRecurse
&& SrcTy
== RI
->getOperand(0)->getType())
3911 // Compare X and Y. Note that the predicate does not change.
3912 if (Value
*V
= simplifyICmpInst(Pred
, SrcOp
, RI
->getOperand(0), Q
,
3916 // Fold (sext X) uge (zext X), (sext X) sle (zext X) to true.
3917 else if (ZExtInst
*RI
= dyn_cast
<ZExtInst
>(RHS
)) {
3918 if (SrcOp
== RI
->getOperand(0)) {
3919 if (Pred
== ICmpInst::ICMP_UGE
|| Pred
== ICmpInst::ICMP_SLE
)
3920 return ConstantInt::getTrue(ITy
);
3921 if (Pred
== ICmpInst::ICMP_ULT
|| Pred
== ICmpInst::ICMP_SGT
)
3922 return ConstantInt::getFalse(ITy
);
3925 // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
3926 // too. If not, then try to deduce the result of the comparison.
3927 else if (match(RHS
, m_ImmConstant())) {
3928 Constant
*C
= cast
<Constant
>(RHS
);
3930 // Compute the constant that would happen if we truncated to SrcTy then
3931 // reextended to DstTy.
3933 ConstantFoldCastOperand(Instruction::Trunc
, C
, SrcTy
, Q
.DL
);
3934 assert(Trunc
&& "Constant-fold of ImmConstant should not fail");
3936 ConstantFoldCastOperand(CastInst::SExt
, Trunc
, DstTy
, Q
.DL
);
3937 assert(RExt
&& "Constant-fold of ImmConstant should not fail");
3939 ConstantFoldCompareInstOperands(ICmpInst::ICMP_EQ
, RExt
, C
, Q
.DL
);
3940 assert(AnyEq
&& "Constant-fold of ImmConstant should not fail");
3942 // If the re-extended constant didn't change then this is effectively
3943 // also a case of comparing two sign-extended values.
3944 if (AnyEq
->isAllOnesValue() && MaxRecurse
)
3946 simplifyICmpInst(Pred
, SrcOp
, Trunc
, Q
, MaxRecurse
- 1))
3949 // Otherwise the upper bits of LHS are all equal, while RHS has varying
3950 // bits there. Use this to work out the result of the comparison.
3951 if (AnyEq
->isNullValue()) {
3954 llvm_unreachable("Unknown ICmp predicate!");
3955 case ICmpInst::ICMP_EQ
:
3956 return Constant::getNullValue(ITy
);
3957 case ICmpInst::ICMP_NE
:
3958 return Constant::getAllOnesValue(ITy
);
3960 // If RHS is non-negative then LHS <s RHS. If RHS is negative then
3962 case ICmpInst::ICMP_SGT
:
3963 case ICmpInst::ICMP_SGE
:
3964 return ConstantExpr::getICmp(ICmpInst::ICMP_SLT
, C
,
3965 Constant::getNullValue(C
->getType()));
3966 case ICmpInst::ICMP_SLT
:
3967 case ICmpInst::ICMP_SLE
:
3968 return ConstantExpr::getICmp(ICmpInst::ICMP_SGE
, C
,
3969 Constant::getNullValue(C
->getType()));
3971 // If LHS is non-negative then LHS <u RHS. If LHS is negative then
3973 case ICmpInst::ICMP_UGT
:
3974 case ICmpInst::ICMP_UGE
:
3975 // Comparison is true iff the LHS <s 0.
3977 if (Value
*V
= simplifyICmpInst(ICmpInst::ICMP_SLT
, SrcOp
,
3978 Constant::getNullValue(SrcTy
), Q
,
3982 case ICmpInst::ICMP_ULT
:
3983 case ICmpInst::ICMP_ULE
:
3984 // Comparison is true iff the LHS >=s 0.
3986 if (Value
*V
= simplifyICmpInst(ICmpInst::ICMP_SGE
, SrcOp
,
3987 Constant::getNullValue(SrcTy
), Q
,
3997 // icmp eq|ne X, Y -> false|true if X != Y
3998 // This is potentially expensive, and we have already computedKnownBits for
3999 // compares with 0 above here, so only try this for a non-zero compare.
4000 if (ICmpInst::isEquality(Pred
) && !match(RHS
, m_Zero()) &&
4001 isKnownNonEqual(LHS
, RHS
, Q
.DL
, Q
.AC
, Q
.CxtI
, Q
.DT
, Q
.IIQ
.UseInstrInfo
)) {
4002 return Pred
== ICmpInst::ICMP_NE
? getTrue(ITy
) : getFalse(ITy
);
4005 if (Value
*V
= simplifyICmpWithBinOp(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4008 if (Value
*V
= simplifyICmpWithMinMax(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4011 if (Value
*V
= simplifyICmpWithIntrinsicOnLHS(Pred
, LHS
, RHS
))
4013 if (Value
*V
= simplifyICmpWithIntrinsicOnLHS(
4014 ICmpInst::getSwappedPredicate(Pred
), RHS
, LHS
))
4017 if (Value
*V
= simplifyICmpWithDominatingAssume(Pred
, LHS
, RHS
, Q
))
4020 if (std::optional
<bool> Res
=
4021 isImpliedByDomCondition(Pred
, LHS
, RHS
, Q
.CxtI
, Q
.DL
))
4022 return ConstantInt::getBool(ITy
, *Res
);
4024 // Simplify comparisons of related pointers using a powerful, recursive
4025 // GEP-walk when we have target data available..
4026 if (LHS
->getType()->isPointerTy())
4027 if (auto *C
= computePointerICmp(Pred
, LHS
, RHS
, Q
))
4029 if (auto *CLHS
= dyn_cast
<PtrToIntOperator
>(LHS
))
4030 if (auto *CRHS
= dyn_cast
<PtrToIntOperator
>(RHS
))
4031 if (CLHS
->getPointerOperandType() == CRHS
->getPointerOperandType() &&
4032 Q
.DL
.getTypeSizeInBits(CLHS
->getPointerOperandType()) ==
4033 Q
.DL
.getTypeSizeInBits(CLHS
->getType()))
4034 if (auto *C
= computePointerICmp(Pred
, CLHS
->getPointerOperand(),
4035 CRHS
->getPointerOperand(), Q
))
4038 // If the comparison is with the result of a select instruction, check whether
4039 // comparing with either branch of the select always yields the same value.
4040 if (isa
<SelectInst
>(LHS
) || isa
<SelectInst
>(RHS
))
4041 if (Value
*V
= threadCmpOverSelect(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4044 // If the comparison is with the result of a phi instruction, check whether
4045 // doing the compare with each incoming phi value yields a common result.
4046 if (isa
<PHINode
>(LHS
) || isa
<PHINode
>(RHS
))
4047 if (Value
*V
= threadCmpOverPHI(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4053 Value
*llvm::simplifyICmpInst(unsigned Predicate
, Value
*LHS
, Value
*RHS
,
4054 const SimplifyQuery
&Q
) {
4055 return ::simplifyICmpInst(Predicate
, LHS
, RHS
, Q
, RecursionLimit
);
4058 /// Given operands for an FCmpInst, see if we can fold the result.
4059 /// If not, this returns null.
4060 static Value
*simplifyFCmpInst(unsigned Predicate
, Value
*LHS
, Value
*RHS
,
4061 FastMathFlags FMF
, const SimplifyQuery
&Q
,
4062 unsigned MaxRecurse
) {
4063 CmpInst::Predicate Pred
= (CmpInst::Predicate
)Predicate
;
4064 assert(CmpInst::isFPPredicate(Pred
) && "Not an FP compare!");
4066 if (Constant
*CLHS
= dyn_cast
<Constant
>(LHS
)) {
4067 if (Constant
*CRHS
= dyn_cast
<Constant
>(RHS
))
4068 return ConstantFoldCompareInstOperands(Pred
, CLHS
, CRHS
, Q
.DL
, Q
.TLI
,
4071 // If we have a constant, make sure it is on the RHS.
4072 std::swap(LHS
, RHS
);
4073 Pred
= CmpInst::getSwappedPredicate(Pred
);
4076 // Fold trivial predicates.
4077 Type
*RetTy
= getCompareTy(LHS
);
4078 if (Pred
== FCmpInst::FCMP_FALSE
)
4079 return getFalse(RetTy
);
4080 if (Pred
== FCmpInst::FCMP_TRUE
)
4081 return getTrue(RetTy
);
4083 // fcmp pred x, poison and fcmp pred poison, x
4085 if (isa
<PoisonValue
>(LHS
) || isa
<PoisonValue
>(RHS
))
4086 return PoisonValue::get(RetTy
);
4088 // fcmp pred x, undef and fcmp pred undef, x
4089 // fold to true if unordered, false if ordered
4090 if (Q
.isUndefValue(LHS
) || Q
.isUndefValue(RHS
)) {
4091 // Choosing NaN for the undef will always make unordered comparison succeed
4092 // and ordered comparison fail.
4093 return ConstantInt::get(RetTy
, CmpInst::isUnordered(Pred
));
4096 // fcmp x,x -> true/false. Not all compares are foldable.
4098 if (CmpInst::isTrueWhenEqual(Pred
))
4099 return getTrue(RetTy
);
4100 if (CmpInst::isFalseWhenEqual(Pred
))
4101 return getFalse(RetTy
);
4104 // Fold (un)ordered comparison if we can determine there are no NaNs.
4106 // This catches the 2 variable input case, constants are handled below as a
4107 // class-like compare.
4108 if (Pred
== FCmpInst::FCMP_ORD
|| Pred
== FCmpInst::FCMP_UNO
) {
4110 (isKnownNeverNaN(RHS
, Q
.DL
, Q
.TLI
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
) &&
4111 isKnownNeverNaN(LHS
, Q
.DL
, Q
.TLI
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
)))
4112 return ConstantInt::get(RetTy
, Pred
== FCmpInst::FCMP_ORD
);
4115 const APFloat
*C
= nullptr;
4116 match(RHS
, m_APFloatAllowUndef(C
));
4117 std::optional
<KnownFPClass
> FullKnownClassLHS
;
4119 // Lazily compute the possible classes for LHS. Avoid computing it twice if
4121 auto computeLHSClass
= [=, &FullKnownClassLHS
](FPClassTest InterestedFlags
=
4123 if (FullKnownClassLHS
)
4124 return *FullKnownClassLHS
;
4125 return computeKnownFPClass(LHS
, FMF
, Q
.DL
, InterestedFlags
, 0, Q
.TLI
, Q
.AC
,
4126 Q
.CxtI
, Q
.DT
, Q
.IIQ
.UseInstrInfo
);
4130 // Fold out compares that express a class test.
4132 // FIXME: Should be able to perform folds without context
4133 // instruction. Always pass in the context function?
4135 const Function
*ParentF
= Q
.CxtI
->getFunction();
4136 auto [ClassVal
, ClassTest
] = fcmpToClassTest(Pred
, *ParentF
, LHS
, C
);
4138 FullKnownClassLHS
= computeLHSClass();
4139 if ((FullKnownClassLHS
->KnownFPClasses
& ClassTest
) == fcNone
)
4140 return getFalse(RetTy
);
4141 if ((FullKnownClassLHS
->KnownFPClasses
& ~ClassTest
) == fcNone
)
4142 return getTrue(RetTy
);
4146 // Handle fcmp with constant RHS.
4148 // TODO: If we always required a context function, we wouldn't need to
4149 // special case nans.
4151 return ConstantInt::get(RetTy
, CmpInst::isUnordered(Pred
));
4153 // TODO: Need version fcmpToClassTest which returns implied class when the
4154 // compare isn't a complete class test. e.g. > 1.0 implies fcPositive, but
4155 // isn't implementable as a class call.
4156 if (C
->isNegative() && !C
->isNegZero()) {
4157 FPClassTest Interested
= KnownFPClass::OrderedLessThanZeroMask
;
4159 // TODO: We can catch more cases by using a range check rather than
4160 // relying on CannotBeOrderedLessThanZero.
4162 case FCmpInst::FCMP_UGE
:
4163 case FCmpInst::FCMP_UGT
:
4164 case FCmpInst::FCMP_UNE
: {
4165 KnownFPClass KnownClass
= computeLHSClass(Interested
);
4167 // (X >= 0) implies (X > C) when (C < 0)
4168 if (KnownClass
.cannotBeOrderedLessThanZero())
4169 return getTrue(RetTy
);
4172 case FCmpInst::FCMP_OEQ
:
4173 case FCmpInst::FCMP_OLE
:
4174 case FCmpInst::FCMP_OLT
: {
4175 KnownFPClass KnownClass
= computeLHSClass(Interested
);
4177 // (X >= 0) implies !(X < C) when (C < 0)
4178 if (KnownClass
.cannotBeOrderedLessThanZero())
4179 return getFalse(RetTy
);
4186 // Check comparison of [minnum/maxnum with constant] with other constant.
4188 if ((match(LHS
, m_Intrinsic
<Intrinsic::minnum
>(m_Value(), m_APFloat(C2
))) &&
4190 (match(LHS
, m_Intrinsic
<Intrinsic::maxnum
>(m_Value(), m_APFloat(C2
))) &&
4193 cast
<IntrinsicInst
>(LHS
)->getIntrinsicID() == Intrinsic::maxnum
;
4194 // The ordered relationship and minnum/maxnum guarantee that we do not
4195 // have NaN constants, so ordered/unordered preds are handled the same.
4197 case FCmpInst::FCMP_OEQ
:
4198 case FCmpInst::FCMP_UEQ
:
4199 // minnum(X, LesserC) == C --> false
4200 // maxnum(X, GreaterC) == C --> false
4201 return getFalse(RetTy
);
4202 case FCmpInst::FCMP_ONE
:
4203 case FCmpInst::FCMP_UNE
:
4204 // minnum(X, LesserC) != C --> true
4205 // maxnum(X, GreaterC) != C --> true
4206 return getTrue(RetTy
);
4207 case FCmpInst::FCMP_OGE
:
4208 case FCmpInst::FCMP_UGE
:
4209 case FCmpInst::FCMP_OGT
:
4210 case FCmpInst::FCMP_UGT
:
4211 // minnum(X, LesserC) >= C --> false
4212 // minnum(X, LesserC) > C --> false
4213 // maxnum(X, GreaterC) >= C --> true
4214 // maxnum(X, GreaterC) > C --> true
4215 return ConstantInt::get(RetTy
, IsMaxNum
);
4216 case FCmpInst::FCMP_OLE
:
4217 case FCmpInst::FCMP_ULE
:
4218 case FCmpInst::FCMP_OLT
:
4219 case FCmpInst::FCMP_ULT
:
4220 // minnum(X, LesserC) <= C --> true
4221 // minnum(X, LesserC) < C --> true
4222 // maxnum(X, GreaterC) <= C --> false
4223 // maxnum(X, GreaterC) < C --> false
4224 return ConstantInt::get(RetTy
, !IsMaxNum
);
4226 // TRUE/FALSE/ORD/UNO should be handled before this.
4227 llvm_unreachable("Unexpected fcmp predicate");
4232 // TODO: Could fold this with above if there were a matcher which returned all
4233 // classes in a non-splat vector.
4234 if (match(RHS
, m_AnyZeroFP())) {
4236 case FCmpInst::FCMP_OGE
:
4237 case FCmpInst::FCMP_ULT
: {
4238 FPClassTest Interested
= KnownFPClass::OrderedLessThanZeroMask
;
4240 Interested
|= fcNan
;
4242 KnownFPClass Known
= computeLHSClass(Interested
);
4244 // Positive or zero X >= 0.0 --> true
4245 // Positive or zero X < 0.0 --> false
4246 if ((FMF
.noNaNs() || Known
.isKnownNeverNaN()) &&
4247 Known
.cannotBeOrderedLessThanZero())
4248 return Pred
== FCmpInst::FCMP_OGE
? getTrue(RetTy
) : getFalse(RetTy
);
4251 case FCmpInst::FCMP_UGE
:
4252 case FCmpInst::FCMP_OLT
: {
4253 FPClassTest Interested
= KnownFPClass::OrderedLessThanZeroMask
;
4254 KnownFPClass Known
= computeLHSClass(Interested
);
4256 // Positive or zero or nan X >= 0.0 --> true
4257 // Positive or zero or nan X < 0.0 --> false
4258 if (Known
.cannotBeOrderedLessThanZero())
4259 return Pred
== FCmpInst::FCMP_UGE
? getTrue(RetTy
) : getFalse(RetTy
);
4267 // If the comparison is with the result of a select instruction, check whether
4268 // comparing with either branch of the select always yields the same value.
4269 if (isa
<SelectInst
>(LHS
) || isa
<SelectInst
>(RHS
))
4270 if (Value
*V
= threadCmpOverSelect(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4273 // If the comparison is with the result of a phi instruction, check whether
4274 // doing the compare with each incoming phi value yields a common result.
4275 if (isa
<PHINode
>(LHS
) || isa
<PHINode
>(RHS
))
4276 if (Value
*V
= threadCmpOverPHI(Pred
, LHS
, RHS
, Q
, MaxRecurse
))
4282 Value
*llvm::simplifyFCmpInst(unsigned Predicate
, Value
*LHS
, Value
*RHS
,
4283 FastMathFlags FMF
, const SimplifyQuery
&Q
) {
4284 return ::simplifyFCmpInst(Predicate
, LHS
, RHS
, FMF
, Q
, RecursionLimit
);
4287 static Value
*simplifyWithOpReplaced(Value
*V
, Value
*Op
, Value
*RepOp
,
4288 const SimplifyQuery
&Q
,
4289 bool AllowRefinement
,
4290 SmallVectorImpl
<Instruction
*> *DropFlags
,
4291 unsigned MaxRecurse
) {
4292 // Trivial replacement.
4299 // We cannot replace a constant, and shouldn't even try.
4300 if (isa
<Constant
>(Op
))
4303 auto *I
= dyn_cast
<Instruction
>(V
);
4307 // The arguments of a phi node might refer to a value from a previous
4309 if (isa
<PHINode
>(I
))
4312 if (Op
->getType()->isVectorTy()) {
4313 // For vector types, the simplification must hold per-lane, so forbid
4314 // potentially cross-lane operations like shufflevector.
4315 if (!I
->getType()->isVectorTy() || isa
<ShuffleVectorInst
>(I
) ||
4316 isa
<CallBase
>(I
) || isa
<BitCastInst
>(I
))
4320 // Don't fold away llvm.is.constant checks based on assumptions.
4321 if (match(I
, m_Intrinsic
<Intrinsic::is_constant
>()))
4324 // Replace Op with RepOp in instruction operands.
4325 SmallVector
<Value
*, 8> NewOps
;
4326 bool AnyReplaced
= false;
4327 for (Value
*InstOp
: I
->operands()) {
4328 if (Value
*NewInstOp
= simplifyWithOpReplaced(
4329 InstOp
, Op
, RepOp
, Q
, AllowRefinement
, DropFlags
, MaxRecurse
)) {
4330 NewOps
.push_back(NewInstOp
);
4331 AnyReplaced
= InstOp
!= NewInstOp
;
4333 NewOps
.push_back(InstOp
);
4340 if (!AllowRefinement
) {
4341 // General InstSimplify functions may refine the result, e.g. by returning
4342 // a constant for a potentially poison value. To avoid this, implement only
4343 // a few non-refining but profitable transforms here.
4345 if (auto *BO
= dyn_cast
<BinaryOperator
>(I
)) {
4346 unsigned Opcode
= BO
->getOpcode();
4347 // id op x -> x, x op id -> x
4348 if (NewOps
[0] == ConstantExpr::getBinOpIdentity(Opcode
, I
->getType()))
4350 if (NewOps
[1] == ConstantExpr::getBinOpIdentity(Opcode
, I
->getType(),
4354 // x & x -> x, x | x -> x
4355 if ((Opcode
== Instruction::And
|| Opcode
== Instruction::Or
) &&
4356 NewOps
[0] == NewOps
[1]) {
4357 // or disjoint x, x results in poison.
4358 if (auto *PDI
= dyn_cast
<PossiblyDisjointInst
>(BO
)) {
4359 if (PDI
->isDisjoint()) {
4362 DropFlags
->push_back(BO
);
4368 // x - x -> 0, x ^ x -> 0. This is non-refining, because x is non-poison
4369 // by assumption and this case never wraps, so nowrap flags can be
4371 if ((Opcode
== Instruction::Sub
|| Opcode
== Instruction::Xor
) &&
4372 NewOps
[0] == RepOp
&& NewOps
[1] == RepOp
)
4373 return Constant::getNullValue(I
->getType());
4375 // If we are substituting an absorber constant into a binop and extra
4376 // poison can't leak if we remove the select -- because both operands of
4377 // the binop are based on the same value -- then it may be safe to replace
4378 // the value with the absorber constant. Examples:
4379 // (Op == 0) ? 0 : (Op & -Op) --> Op & -Op
4380 // (Op == 0) ? 0 : (Op * (binop Op, C)) --> Op * (binop Op, C)
4381 // (Op == -1) ? -1 : (Op | (binop C, Op) --> Op | (binop C, Op)
4382 Constant
*Absorber
=
4383 ConstantExpr::getBinOpAbsorber(Opcode
, I
->getType());
4384 if ((NewOps
[0] == Absorber
|| NewOps
[1] == Absorber
) &&
4385 impliesPoison(BO
, Op
))
4389 if (isa
<GetElementPtrInst
>(I
)) {
4390 // getelementptr x, 0 -> x.
4391 // This never returns poison, even if inbounds is set.
4392 if (NewOps
.size() == 2 && match(NewOps
[1], m_Zero()))
4396 // The simplification queries below may return the original value. Consider:
4397 // %div = udiv i32 %arg, %arg2
4398 // %mul = mul nsw i32 %div, %arg2
4399 // %cmp = icmp eq i32 %mul, %arg
4400 // %sel = select i1 %cmp, i32 %div, i32 undef
4401 // Replacing %arg by %mul, %div becomes "udiv i32 %mul, %arg2", which
4402 // simplifies back to %arg. This can only happen because %mul does not
4403 // dominate %div. To ensure a consistent return value contract, we make sure
4404 // that this case returns nullptr as well.
4405 auto PreventSelfSimplify
= [V
](Value
*Simplified
) {
4406 return Simplified
!= V
? Simplified
: nullptr;
4409 return PreventSelfSimplify(
4410 ::simplifyInstructionWithOperands(I
, NewOps
, Q
, MaxRecurse
));
4413 // If all operands are constant after substituting Op for RepOp then we can
4414 // constant fold the instruction.
4415 SmallVector
<Constant
*, 8> ConstOps
;
4416 for (Value
*NewOp
: NewOps
) {
4417 if (Constant
*ConstOp
= dyn_cast
<Constant
>(NewOp
))
4418 ConstOps
.push_back(ConstOp
);
4424 // %cmp = icmp eq i32 %x, 2147483647
4425 // %add = add nsw i32 %x, 1
4426 // %sel = select i1 %cmp, i32 -2147483648, i32 %add
4428 // We can't replace %sel with %add unless we strip away the flags (which
4429 // will be done in InstCombine).
4430 // TODO: This may be unsound, because it only catches some forms of
4432 if (!AllowRefinement
) {
4433 if (canCreatePoison(cast
<Operator
>(I
), !DropFlags
)) {
4434 // abs cannot create poison if the value is known to never be int_min.
4435 if (auto *II
= dyn_cast
<IntrinsicInst
>(I
);
4436 II
&& II
->getIntrinsicID() == Intrinsic::abs
) {
4437 if (!ConstOps
[0]->isNotMinSignedValue())
4442 Constant
*Res
= ConstantFoldInstOperands(I
, ConstOps
, Q
.DL
, Q
.TLI
);
4443 if (DropFlags
&& Res
&& I
->hasPoisonGeneratingFlagsOrMetadata())
4444 DropFlags
->push_back(I
);
4448 return ConstantFoldInstOperands(I
, ConstOps
, Q
.DL
, Q
.TLI
);
4451 Value
*llvm::simplifyWithOpReplaced(Value
*V
, Value
*Op
, Value
*RepOp
,
4452 const SimplifyQuery
&Q
,
4453 bool AllowRefinement
,
4454 SmallVectorImpl
<Instruction
*> *DropFlags
) {
4455 return ::simplifyWithOpReplaced(V
, Op
, RepOp
, Q
, AllowRefinement
, DropFlags
,
4459 /// Try to simplify a select instruction when its condition operand is an
4460 /// integer comparison where one operand of the compare is a constant.
4461 static Value
*simplifySelectBitTest(Value
*TrueVal
, Value
*FalseVal
, Value
*X
,
4462 const APInt
*Y
, bool TrueWhenUnset
) {
4465 // (X & Y) == 0 ? X & ~Y : X --> X
4466 // (X & Y) != 0 ? X & ~Y : X --> X & ~Y
4467 if (FalseVal
== X
&& match(TrueVal
, m_And(m_Specific(X
), m_APInt(C
))) &&
4469 return TrueWhenUnset
? FalseVal
: TrueVal
;
4471 // (X & Y) == 0 ? X : X & ~Y --> X & ~Y
4472 // (X & Y) != 0 ? X : X & ~Y --> X
4473 if (TrueVal
== X
&& match(FalseVal
, m_And(m_Specific(X
), m_APInt(C
))) &&
4475 return TrueWhenUnset
? FalseVal
: TrueVal
;
4477 if (Y
->isPowerOf2()) {
4478 // (X & Y) == 0 ? X | Y : X --> X | Y
4479 // (X & Y) != 0 ? X | Y : X --> X
4480 if (FalseVal
== X
&& match(TrueVal
, m_Or(m_Specific(X
), m_APInt(C
))) &&
4482 // We can't return the or if it has the disjoint flag.
4483 if (TrueWhenUnset
&& cast
<PossiblyDisjointInst
>(TrueVal
)->isDisjoint())
4485 return TrueWhenUnset
? TrueVal
: FalseVal
;
4488 // (X & Y) == 0 ? X : X | Y --> X
4489 // (X & Y) != 0 ? X : X | Y --> X | Y
4490 if (TrueVal
== X
&& match(FalseVal
, m_Or(m_Specific(X
), m_APInt(C
))) &&
4492 // We can't return the or if it has the disjoint flag.
4493 if (!TrueWhenUnset
&& cast
<PossiblyDisjointInst
>(FalseVal
)->isDisjoint())
4495 return TrueWhenUnset
? TrueVal
: FalseVal
;
4502 static Value
*simplifyCmpSelOfMaxMin(Value
*CmpLHS
, Value
*CmpRHS
,
4503 ICmpInst::Predicate Pred
, Value
*TVal
,
4505 // Canonicalize common cmp+sel operand as CmpLHS.
4506 if (CmpRHS
== TVal
|| CmpRHS
== FVal
) {
4507 std::swap(CmpLHS
, CmpRHS
);
4508 Pred
= ICmpInst::getSwappedPredicate(Pred
);
4511 // Canonicalize common cmp+sel operand as TVal.
4512 if (CmpLHS
== FVal
) {
4513 std::swap(TVal
, FVal
);
4514 Pred
= ICmpInst::getInversePredicate(Pred
);
4517 // A vector select may be shuffling together elements that are equivalent
4518 // based on the max/min/select relationship.
4519 Value
*X
= CmpLHS
, *Y
= CmpRHS
;
4520 bool PeekedThroughSelectShuffle
= false;
4521 auto *Shuf
= dyn_cast
<ShuffleVectorInst
>(FVal
);
4522 if (Shuf
&& Shuf
->isSelect()) {
4523 if (Shuf
->getOperand(0) == Y
)
4524 FVal
= Shuf
->getOperand(1);
4525 else if (Shuf
->getOperand(1) == Y
)
4526 FVal
= Shuf
->getOperand(0);
4529 PeekedThroughSelectShuffle
= true;
4532 // (X pred Y) ? X : max/min(X, Y)
4533 auto *MMI
= dyn_cast
<MinMaxIntrinsic
>(FVal
);
4534 if (!MMI
|| TVal
!= X
||
4535 !match(FVal
, m_c_MaxOrMin(m_Specific(X
), m_Specific(Y
))))
4538 // (X > Y) ? X : max(X, Y) --> max(X, Y)
4539 // (X >= Y) ? X : max(X, Y) --> max(X, Y)
4540 // (X < Y) ? X : min(X, Y) --> min(X, Y)
4541 // (X <= Y) ? X : min(X, Y) --> min(X, Y)
4543 // The equivalence allows a vector select (shuffle) of max/min and Y. Ex:
4544 // (X > Y) ? X : (Z ? max(X, Y) : Y)
4545 // If Z is true, this reduces as above, and if Z is false:
4546 // (X > Y) ? X : Y --> max(X, Y)
4547 ICmpInst::Predicate MMPred
= MMI
->getPredicate();
4548 if (MMPred
== CmpInst::getStrictPredicate(Pred
))
4551 // Other transforms are not valid with a shuffle.
4552 if (PeekedThroughSelectShuffle
)
4555 // (X == Y) ? X : max/min(X, Y) --> max/min(X, Y)
4556 if (Pred
== CmpInst::ICMP_EQ
)
4559 // (X != Y) ? X : max/min(X, Y) --> X
4560 if (Pred
== CmpInst::ICMP_NE
)
4563 // (X < Y) ? X : max(X, Y) --> X
4564 // (X <= Y) ? X : max(X, Y) --> X
4565 // (X > Y) ? X : min(X, Y) --> X
4566 // (X >= Y) ? X : min(X, Y) --> X
4567 ICmpInst::Predicate InvPred
= CmpInst::getInversePredicate(Pred
);
4568 if (MMPred
== CmpInst::getStrictPredicate(InvPred
))
4574 /// An alternative way to test if a bit is set or not uses sgt/slt instead of
4576 static Value
*simplifySelectWithFakeICmpEq(Value
*CmpLHS
, Value
*CmpRHS
,
4577 ICmpInst::Predicate Pred
,
4578 Value
*TrueVal
, Value
*FalseVal
) {
4581 if (!decomposeBitTestICmp(CmpLHS
, CmpRHS
, Pred
, X
, Mask
))
4584 return simplifySelectBitTest(TrueVal
, FalseVal
, X
, &Mask
,
4585 Pred
== ICmpInst::ICMP_EQ
);
4588 /// Try to simplify a select instruction when its condition operand is an
4589 /// integer equality comparison.
4590 static Value
*simplifySelectWithICmpEq(Value
*CmpLHS
, Value
*CmpRHS
,
4591 Value
*TrueVal
, Value
*FalseVal
,
4592 const SimplifyQuery
&Q
,
4593 unsigned MaxRecurse
) {
4594 if (simplifyWithOpReplaced(FalseVal
, CmpLHS
, CmpRHS
, Q
,
4595 /* AllowRefinement */ false,
4596 /* DropFlags */ nullptr, MaxRecurse
) == TrueVal
)
4598 if (simplifyWithOpReplaced(TrueVal
, CmpLHS
, CmpRHS
, Q
,
4599 /* AllowRefinement */ true,
4600 /* DropFlags */ nullptr, MaxRecurse
) == FalseVal
)
4606 /// Try to simplify a select instruction when its condition operand is an
4607 /// integer comparison.
4608 static Value
*simplifySelectWithICmpCond(Value
*CondVal
, Value
*TrueVal
,
4610 const SimplifyQuery
&Q
,
4611 unsigned MaxRecurse
) {
4612 ICmpInst::Predicate Pred
;
4613 Value
*CmpLHS
, *CmpRHS
;
4614 if (!match(CondVal
, m_ICmp(Pred
, m_Value(CmpLHS
), m_Value(CmpRHS
))))
4617 if (Value
*V
= simplifyCmpSelOfMaxMin(CmpLHS
, CmpRHS
, Pred
, TrueVal
, FalseVal
))
4620 // Canonicalize ne to eq predicate.
4621 if (Pred
== ICmpInst::ICMP_NE
) {
4622 Pred
= ICmpInst::ICMP_EQ
;
4623 std::swap(TrueVal
, FalseVal
);
4626 // Check for integer min/max with a limit constant:
4627 // X > MIN_INT ? X : MIN_INT --> X
4628 // X < MAX_INT ? X : MAX_INT --> X
4629 if (TrueVal
->getType()->isIntOrIntVectorTy()) {
4631 SelectPatternFlavor SPF
=
4632 matchDecomposedSelectPattern(cast
<ICmpInst
>(CondVal
), TrueVal
, FalseVal
,
4635 if (SelectPatternResult::isMinOrMax(SPF
) && Pred
== getMinMaxPred(SPF
)) {
4636 APInt LimitC
= getMinMaxLimit(getInverseMinMaxFlavor(SPF
),
4637 X
->getType()->getScalarSizeInBits());
4638 if (match(Y
, m_SpecificInt(LimitC
)))
4643 if (Pred
== ICmpInst::ICMP_EQ
&& match(CmpRHS
, m_Zero())) {
4646 if (match(CmpLHS
, m_And(m_Value(X
), m_APInt(Y
))))
4647 if (Value
*V
= simplifySelectBitTest(TrueVal
, FalseVal
, X
, Y
,
4648 /*TrueWhenUnset=*/true))
4651 // Test for a bogus zero-shift-guard-op around funnel-shift or rotate.
4653 auto isFsh
= m_CombineOr(m_FShl(m_Value(X
), m_Value(), m_Value(ShAmt
)),
4654 m_FShr(m_Value(), m_Value(X
), m_Value(ShAmt
)));
4655 // (ShAmt == 0) ? fshl(X, *, ShAmt) : X --> X
4656 // (ShAmt == 0) ? fshr(*, X, ShAmt) : X --> X
4657 if (match(TrueVal
, isFsh
) && FalseVal
== X
&& CmpLHS
== ShAmt
)
4660 // Test for a zero-shift-guard-op around rotates. These are used to
4661 // avoid UB from oversized shifts in raw IR rotate patterns, but the
4662 // intrinsics do not have that problem.
4663 // We do not allow this transform for the general funnel shift case because
4664 // that would not preserve the poison safety of the original code.
4666 m_CombineOr(m_FShl(m_Value(X
), m_Deferred(X
), m_Value(ShAmt
)),
4667 m_FShr(m_Value(X
), m_Deferred(X
), m_Value(ShAmt
)));
4668 // (ShAmt == 0) ? X : fshl(X, X, ShAmt) --> fshl(X, X, ShAmt)
4669 // (ShAmt == 0) ? X : fshr(X, X, ShAmt) --> fshr(X, X, ShAmt)
4670 if (match(FalseVal
, isRotate
) && TrueVal
== X
&& CmpLHS
== ShAmt
&&
4671 Pred
== ICmpInst::ICMP_EQ
)
4674 // X == 0 ? abs(X) : -abs(X) --> -abs(X)
4675 // X == 0 ? -abs(X) : abs(X) --> abs(X)
4676 if (match(TrueVal
, m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
))) &&
4677 match(FalseVal
, m_Neg(m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
)))))
4680 m_Neg(m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
)))) &&
4681 match(FalseVal
, m_Intrinsic
<Intrinsic::abs
>(m_Specific(CmpLHS
))))
4685 // Check for other compares that behave like bit test.
4687 simplifySelectWithFakeICmpEq(CmpLHS
, CmpRHS
, Pred
, TrueVal
, FalseVal
))
4690 // If we have a scalar equality comparison, then we know the value in one of
4691 // the arms of the select. See if substituting this value into the arm and
4692 // simplifying the result yields the same value as the other arm.
4693 if (Pred
== ICmpInst::ICMP_EQ
) {
4694 if (Value
*V
= simplifySelectWithICmpEq(CmpLHS
, CmpRHS
, TrueVal
, FalseVal
,
4697 if (Value
*V
= simplifySelectWithICmpEq(CmpRHS
, CmpLHS
, TrueVal
, FalseVal
,
4703 // select((X | Y) == 0 ? X : 0) --> 0 (commuted 2 ways)
4704 if (match(CmpLHS
, m_Or(m_Value(X
), m_Value(Y
))) &&
4705 match(CmpRHS
, m_Zero())) {
4706 // (X | Y) == 0 implies X == 0 and Y == 0.
4707 if (Value
*V
= simplifySelectWithICmpEq(X
, CmpRHS
, TrueVal
, FalseVal
, Q
,
4710 if (Value
*V
= simplifySelectWithICmpEq(Y
, CmpRHS
, TrueVal
, FalseVal
, Q
,
4715 // select((X & Y) == -1 ? X : -1) --> -1 (commuted 2 ways)
4716 if (match(CmpLHS
, m_And(m_Value(X
), m_Value(Y
))) &&
4717 match(CmpRHS
, m_AllOnes())) {
4718 // (X & Y) == -1 implies X == -1 and Y == -1.
4719 if (Value
*V
= simplifySelectWithICmpEq(X
, CmpRHS
, TrueVal
, FalseVal
, Q
,
4722 if (Value
*V
= simplifySelectWithICmpEq(Y
, CmpRHS
, TrueVal
, FalseVal
, Q
,
4731 /// Try to simplify a select instruction when its condition operand is a
4732 /// floating-point comparison.
4733 static Value
*simplifySelectWithFCmp(Value
*Cond
, Value
*T
, Value
*F
,
4734 const SimplifyQuery
&Q
) {
4735 FCmpInst::Predicate Pred
;
4736 if (!match(Cond
, m_FCmp(Pred
, m_Specific(T
), m_Specific(F
))) &&
4737 !match(Cond
, m_FCmp(Pred
, m_Specific(F
), m_Specific(T
))))
4740 // This transform is safe if we do not have (do not care about) -0.0 or if
4741 // at least one operand is known to not be -0.0. Otherwise, the select can
4742 // change the sign of a zero operand.
4743 bool HasNoSignedZeros
=
4744 Q
.CxtI
&& isa
<FPMathOperator
>(Q
.CxtI
) && Q
.CxtI
->hasNoSignedZeros();
4746 if (HasNoSignedZeros
|| (match(T
, m_APFloat(C
)) && C
->isNonZero()) ||
4747 (match(F
, m_APFloat(C
)) && C
->isNonZero())) {
4748 // (T == F) ? T : F --> F
4749 // (F == T) ? T : F --> F
4750 if (Pred
== FCmpInst::FCMP_OEQ
)
4753 // (T != F) ? T : F --> T
4754 // (F != T) ? T : F --> T
4755 if (Pred
== FCmpInst::FCMP_UNE
)
4762 /// Given operands for a SelectInst, see if we can fold the result.
4763 /// If not, this returns null.
4764 static Value
*simplifySelectInst(Value
*Cond
, Value
*TrueVal
, Value
*FalseVal
,
4765 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
4766 if (auto *CondC
= dyn_cast
<Constant
>(Cond
)) {
4767 if (auto *TrueC
= dyn_cast
<Constant
>(TrueVal
))
4768 if (auto *FalseC
= dyn_cast
<Constant
>(FalseVal
))
4769 if (Constant
*C
= ConstantFoldSelectInstruction(CondC
, TrueC
, FalseC
))
4772 // select poison, X, Y -> poison
4773 if (isa
<PoisonValue
>(CondC
))
4774 return PoisonValue::get(TrueVal
->getType());
4776 // select undef, X, Y -> X or Y
4777 if (Q
.isUndefValue(CondC
))
4778 return isa
<Constant
>(FalseVal
) ? FalseVal
: TrueVal
;
4780 // select true, X, Y --> X
4781 // select false, X, Y --> Y
4782 // For vectors, allow undef/poison elements in the condition to match the
4783 // defined elements, so we can eliminate the select.
4784 if (match(CondC
, m_One()))
4786 if (match(CondC
, m_Zero()))
4790 assert(Cond
->getType()->isIntOrIntVectorTy(1) &&
4791 "Select must have bool or bool vector condition");
4792 assert(TrueVal
->getType() == FalseVal
->getType() &&
4793 "Select must have same types for true/false ops");
4795 if (Cond
->getType() == TrueVal
->getType()) {
4796 // select i1 Cond, i1 true, i1 false --> i1 Cond
4797 if (match(TrueVal
, m_One()) && match(FalseVal
, m_ZeroInt()))
4800 // (X && Y) ? X : Y --> Y (commuted 2 ways)
4801 if (match(Cond
, m_c_LogicalAnd(m_Specific(TrueVal
), m_Specific(FalseVal
))))
4804 // (X || Y) ? X : Y --> X (commuted 2 ways)
4805 if (match(Cond
, m_c_LogicalOr(m_Specific(TrueVal
), m_Specific(FalseVal
))))
4808 // (X || Y) ? false : X --> false (commuted 2 ways)
4809 if (match(Cond
, m_c_LogicalOr(m_Specific(FalseVal
), m_Value())) &&
4810 match(TrueVal
, m_ZeroInt()))
4811 return ConstantInt::getFalse(Cond
->getType());
4813 // Match patterns that end in logical-and.
4814 if (match(FalseVal
, m_ZeroInt())) {
4815 // !(X || Y) && X --> false (commuted 2 ways)
4816 if (match(Cond
, m_Not(m_c_LogicalOr(m_Specific(TrueVal
), m_Value()))))
4817 return ConstantInt::getFalse(Cond
->getType());
4818 // X && !(X || Y) --> false (commuted 2 ways)
4819 if (match(TrueVal
, m_Not(m_c_LogicalOr(m_Specific(Cond
), m_Value()))))
4820 return ConstantInt::getFalse(Cond
->getType());
4822 // (X || Y) && Y --> Y (commuted 2 ways)
4823 if (match(Cond
, m_c_LogicalOr(m_Specific(TrueVal
), m_Value())))
4825 // Y && (X || Y) --> Y (commuted 2 ways)
4826 if (match(TrueVal
, m_c_LogicalOr(m_Specific(Cond
), m_Value())))
4829 // (X || Y) && (X || !Y) --> X (commuted 8 ways)
4831 if (match(Cond
, m_c_LogicalOr(m_Value(X
), m_Not(m_Value(Y
)))) &&
4832 match(TrueVal
, m_c_LogicalOr(m_Specific(X
), m_Specific(Y
))))
4834 if (match(TrueVal
, m_c_LogicalOr(m_Value(X
), m_Not(m_Value(Y
)))) &&
4835 match(Cond
, m_c_LogicalOr(m_Specific(X
), m_Specific(Y
))))
4839 // Match patterns that end in logical-or.
4840 if (match(TrueVal
, m_One())) {
4841 // !(X && Y) || X --> true (commuted 2 ways)
4842 if (match(Cond
, m_Not(m_c_LogicalAnd(m_Specific(FalseVal
), m_Value()))))
4843 return ConstantInt::getTrue(Cond
->getType());
4844 // X || !(X && Y) --> true (commuted 2 ways)
4845 if (match(FalseVal
, m_Not(m_c_LogicalAnd(m_Specific(Cond
), m_Value()))))
4846 return ConstantInt::getTrue(Cond
->getType());
4848 // (X && Y) || Y --> Y (commuted 2 ways)
4849 if (match(Cond
, m_c_LogicalAnd(m_Specific(FalseVal
), m_Value())))
4851 // Y || (X && Y) --> Y (commuted 2 ways)
4852 if (match(FalseVal
, m_c_LogicalAnd(m_Specific(Cond
), m_Value())))
4857 // select ?, X, X -> X
4858 if (TrueVal
== FalseVal
)
4861 if (Cond
== TrueVal
) {
4862 // select i1 X, i1 X, i1 false --> X (logical-and)
4863 if (match(FalseVal
, m_ZeroInt()))
4865 // select i1 X, i1 X, i1 true --> true
4866 if (match(FalseVal
, m_One()))
4867 return ConstantInt::getTrue(Cond
->getType());
4869 if (Cond
== FalseVal
) {
4870 // select i1 X, i1 true, i1 X --> X (logical-or)
4871 if (match(TrueVal
, m_One()))
4873 // select i1 X, i1 false, i1 X --> false
4874 if (match(TrueVal
, m_ZeroInt()))
4875 return ConstantInt::getFalse(Cond
->getType());
4878 // If the true or false value is poison, we can fold to the other value.
4879 // If the true or false value is undef, we can fold to the other value as
4880 // long as the other value isn't poison.
4881 // select ?, poison, X -> X
4882 // select ?, undef, X -> X
4883 if (isa
<PoisonValue
>(TrueVal
) ||
4884 (Q
.isUndefValue(TrueVal
) && impliesPoison(FalseVal
, Cond
)))
4886 // select ?, X, poison -> X
4887 // select ?, X, undef -> X
4888 if (isa
<PoisonValue
>(FalseVal
) ||
4889 (Q
.isUndefValue(FalseVal
) && impliesPoison(TrueVal
, Cond
)))
4892 // Deal with partial undef vector constants: select ?, VecC, VecC' --> VecC''
4893 Constant
*TrueC
, *FalseC
;
4894 if (isa
<FixedVectorType
>(TrueVal
->getType()) &&
4895 match(TrueVal
, m_Constant(TrueC
)) &&
4896 match(FalseVal
, m_Constant(FalseC
))) {
4898 cast
<FixedVectorType
>(TrueC
->getType())->getNumElements();
4899 SmallVector
<Constant
*, 16> NewC
;
4900 for (unsigned i
= 0; i
!= NumElts
; ++i
) {
4901 // Bail out on incomplete vector constants.
4902 Constant
*TEltC
= TrueC
->getAggregateElement(i
);
4903 Constant
*FEltC
= FalseC
->getAggregateElement(i
);
4904 if (!TEltC
|| !FEltC
)
4907 // If the elements match (undef or not), that value is the result. If only
4908 // one element is undef, choose the defined element as the safe result.
4910 NewC
.push_back(TEltC
);
4911 else if (isa
<PoisonValue
>(TEltC
) ||
4912 (Q
.isUndefValue(TEltC
) && isGuaranteedNotToBePoison(FEltC
)))
4913 NewC
.push_back(FEltC
);
4914 else if (isa
<PoisonValue
>(FEltC
) ||
4915 (Q
.isUndefValue(FEltC
) && isGuaranteedNotToBePoison(TEltC
)))
4916 NewC
.push_back(TEltC
);
4920 if (NewC
.size() == NumElts
)
4921 return ConstantVector::get(NewC
);
4925 simplifySelectWithICmpCond(Cond
, TrueVal
, FalseVal
, Q
, MaxRecurse
))
4928 if (Value
*V
= simplifySelectWithFCmp(Cond
, TrueVal
, FalseVal
, Q
))
4931 if (Value
*V
= foldSelectWithBinaryOp(Cond
, TrueVal
, FalseVal
))
4934 std::optional
<bool> Imp
= isImpliedByDomCondition(Cond
, Q
.CxtI
, Q
.DL
);
4936 return *Imp
? TrueVal
: FalseVal
;
4941 Value
*llvm::simplifySelectInst(Value
*Cond
, Value
*TrueVal
, Value
*FalseVal
,
4942 const SimplifyQuery
&Q
) {
4943 return ::simplifySelectInst(Cond
, TrueVal
, FalseVal
, Q
, RecursionLimit
);
4946 /// Given operands for an GetElementPtrInst, see if we can fold the result.
4947 /// If not, this returns null.
4948 static Value
*simplifyGEPInst(Type
*SrcTy
, Value
*Ptr
,
4949 ArrayRef
<Value
*> Indices
, bool InBounds
,
4950 const SimplifyQuery
&Q
, unsigned) {
4951 // The type of the GEP pointer operand.
4953 cast
<PointerType
>(Ptr
->getType()->getScalarType())->getAddressSpace();
4955 // getelementptr P -> P.
4956 if (Indices
.empty())
4959 // Compute the (pointer) type returned by the GEP instruction.
4960 Type
*LastType
= GetElementPtrInst::getIndexedType(SrcTy
, Indices
);
4961 Type
*GEPTy
= Ptr
->getType();
4962 if (!GEPTy
->isVectorTy()) {
4963 for (Value
*Op
: Indices
) {
4964 // If one of the operands is a vector, the result type is a vector of
4965 // pointers. All vector operands must have the same number of elements.
4966 if (VectorType
*VT
= dyn_cast
<VectorType
>(Op
->getType())) {
4967 GEPTy
= VectorType::get(GEPTy
, VT
->getElementCount());
4973 // All-zero GEP is a no-op, unless it performs a vector splat.
4974 if (Ptr
->getType() == GEPTy
&&
4975 all_of(Indices
, [](const auto *V
) { return match(V
, m_Zero()); }))
4978 // getelementptr poison, idx -> poison
4979 // getelementptr baseptr, poison -> poison
4980 if (isa
<PoisonValue
>(Ptr
) ||
4981 any_of(Indices
, [](const auto *V
) { return isa
<PoisonValue
>(V
); }))
4982 return PoisonValue::get(GEPTy
);
4984 // getelementptr undef, idx -> undef
4985 if (Q
.isUndefValue(Ptr
))
4986 return UndefValue::get(GEPTy
);
4988 bool IsScalableVec
=
4989 SrcTy
->isScalableTy() || any_of(Indices
, [](const Value
*V
) {
4990 return isa
<ScalableVectorType
>(V
->getType());
4993 if (Indices
.size() == 1) {
4995 if (!IsScalableVec
&& Ty
->isSized()) {
4998 uint64_t TyAllocSize
= Q
.DL
.getTypeAllocSize(Ty
);
4999 // getelementptr P, N -> P if P points to a type of zero size.
5000 if (TyAllocSize
== 0 && Ptr
->getType() == GEPTy
)
5003 // The following transforms are only safe if the ptrtoint cast
5004 // doesn't truncate the pointers.
5005 if (Indices
[0]->getType()->getScalarSizeInBits() ==
5006 Q
.DL
.getPointerSizeInBits(AS
)) {
5007 auto CanSimplify
= [GEPTy
, &P
, Ptr
]() -> bool {
5008 return P
->getType() == GEPTy
&&
5009 getUnderlyingObject(P
) == getUnderlyingObject(Ptr
);
5011 // getelementptr V, (sub P, V) -> P if P points to a type of size 1.
5012 if (TyAllocSize
== 1 &&
5014 m_Sub(m_PtrToInt(m_Value(P
)), m_PtrToInt(m_Specific(Ptr
)))) &&
5018 // getelementptr V, (ashr (sub P, V), C) -> P if P points to a type of
5020 if (match(Indices
[0], m_AShr(m_Sub(m_PtrToInt(m_Value(P
)),
5021 m_PtrToInt(m_Specific(Ptr
))),
5022 m_ConstantInt(C
))) &&
5023 TyAllocSize
== 1ULL << C
&& CanSimplify())
5026 // getelementptr V, (sdiv (sub P, V), C) -> P if P points to a type of
5028 if (match(Indices
[0], m_SDiv(m_Sub(m_PtrToInt(m_Value(P
)),
5029 m_PtrToInt(m_Specific(Ptr
))),
5030 m_SpecificInt(TyAllocSize
))) &&
5037 if (!IsScalableVec
&& Q
.DL
.getTypeAllocSize(LastType
) == 1 &&
5038 all_of(Indices
.drop_back(1),
5039 [](Value
*Idx
) { return match(Idx
, m_Zero()); })) {
5041 Q
.DL
.getIndexSizeInBits(Ptr
->getType()->getPointerAddressSpace());
5042 if (Q
.DL
.getTypeSizeInBits(Indices
.back()->getType()) == IdxWidth
) {
5043 APInt
BasePtrOffset(IdxWidth
, 0);
5044 Value
*StrippedBasePtr
=
5045 Ptr
->stripAndAccumulateInBoundsConstantOffsets(Q
.DL
, BasePtrOffset
);
5047 // Avoid creating inttoptr of zero here: While LLVMs treatment of
5048 // inttoptr is generally conservative, this particular case is folded to
5049 // a null pointer, which will have incorrect provenance.
5051 // gep (gep V, C), (sub 0, V) -> C
5052 if (match(Indices
.back(),
5053 m_Sub(m_Zero(), m_PtrToInt(m_Specific(StrippedBasePtr
)))) &&
5054 !BasePtrOffset
.isZero()) {
5055 auto *CI
= ConstantInt::get(GEPTy
->getContext(), BasePtrOffset
);
5056 return ConstantExpr::getIntToPtr(CI
, GEPTy
);
5058 // gep (gep V, C), (xor V, -1) -> C-1
5059 if (match(Indices
.back(),
5060 m_Xor(m_PtrToInt(m_Specific(StrippedBasePtr
)), m_AllOnes())) &&
5061 !BasePtrOffset
.isOne()) {
5062 auto *CI
= ConstantInt::get(GEPTy
->getContext(), BasePtrOffset
- 1);
5063 return ConstantExpr::getIntToPtr(CI
, GEPTy
);
5068 // Check to see if this is constant foldable.
5069 if (!isa
<Constant
>(Ptr
) ||
5070 !all_of(Indices
, [](Value
*V
) { return isa
<Constant
>(V
); }))
5073 if (!ConstantExpr::isSupportedGetElementPtr(SrcTy
))
5074 return ConstantFoldGetElementPtr(SrcTy
, cast
<Constant
>(Ptr
), InBounds
,
5075 std::nullopt
, Indices
);
5077 auto *CE
= ConstantExpr::getGetElementPtr(SrcTy
, cast
<Constant
>(Ptr
), Indices
,
5079 return ConstantFoldConstant(CE
, Q
.DL
);
5082 Value
*llvm::simplifyGEPInst(Type
*SrcTy
, Value
*Ptr
, ArrayRef
<Value
*> Indices
,
5083 bool InBounds
, const SimplifyQuery
&Q
) {
5084 return ::simplifyGEPInst(SrcTy
, Ptr
, Indices
, InBounds
, Q
, RecursionLimit
);
5087 /// Given operands for an InsertValueInst, see if we can fold the result.
5088 /// If not, this returns null.
5089 static Value
*simplifyInsertValueInst(Value
*Agg
, Value
*Val
,
5090 ArrayRef
<unsigned> Idxs
,
5091 const SimplifyQuery
&Q
, unsigned) {
5092 if (Constant
*CAgg
= dyn_cast
<Constant
>(Agg
))
5093 if (Constant
*CVal
= dyn_cast
<Constant
>(Val
))
5094 return ConstantFoldInsertValueInstruction(CAgg
, CVal
, Idxs
);
5096 // insertvalue x, poison, n -> x
5097 // insertvalue x, undef, n -> x if x cannot be poison
5098 if (isa
<PoisonValue
>(Val
) ||
5099 (Q
.isUndefValue(Val
) && isGuaranteedNotToBePoison(Agg
)))
5102 // insertvalue x, (extractvalue y, n), n
5103 if (ExtractValueInst
*EV
= dyn_cast
<ExtractValueInst
>(Val
))
5104 if (EV
->getAggregateOperand()->getType() == Agg
->getType() &&
5105 EV
->getIndices() == Idxs
) {
5106 // insertvalue poison, (extractvalue y, n), n -> y
5107 // insertvalue undef, (extractvalue y, n), n -> y if y cannot be poison
5108 if (isa
<PoisonValue
>(Agg
) ||
5109 (Q
.isUndefValue(Agg
) &&
5110 isGuaranteedNotToBePoison(EV
->getAggregateOperand())))
5111 return EV
->getAggregateOperand();
5113 // insertvalue y, (extractvalue y, n), n -> y
5114 if (Agg
== EV
->getAggregateOperand())
5121 Value
*llvm::simplifyInsertValueInst(Value
*Agg
, Value
*Val
,
5122 ArrayRef
<unsigned> Idxs
,
5123 const SimplifyQuery
&Q
) {
5124 return ::simplifyInsertValueInst(Agg
, Val
, Idxs
, Q
, RecursionLimit
);
5127 Value
*llvm::simplifyInsertElementInst(Value
*Vec
, Value
*Val
, Value
*Idx
,
5128 const SimplifyQuery
&Q
) {
5129 // Try to constant fold.
5130 auto *VecC
= dyn_cast
<Constant
>(Vec
);
5131 auto *ValC
= dyn_cast
<Constant
>(Val
);
5132 auto *IdxC
= dyn_cast
<Constant
>(Idx
);
5133 if (VecC
&& ValC
&& IdxC
)
5134 return ConstantExpr::getInsertElement(VecC
, ValC
, IdxC
);
5136 // For fixed-length vector, fold into poison if index is out of bounds.
5137 if (auto *CI
= dyn_cast
<ConstantInt
>(Idx
)) {
5138 if (isa
<FixedVectorType
>(Vec
->getType()) &&
5139 CI
->uge(cast
<FixedVectorType
>(Vec
->getType())->getNumElements()))
5140 return PoisonValue::get(Vec
->getType());
5143 // If index is undef, it might be out of bounds (see above case)
5144 if (Q
.isUndefValue(Idx
))
5145 return PoisonValue::get(Vec
->getType());
5147 // If the scalar is poison, or it is undef and there is no risk of
5148 // propagating poison from the vector value, simplify to the vector value.
5149 if (isa
<PoisonValue
>(Val
) ||
5150 (Q
.isUndefValue(Val
) && isGuaranteedNotToBePoison(Vec
)))
5153 // If we are extracting a value from a vector, then inserting it into the same
5154 // place, that's the input vector:
5155 // insertelt Vec, (extractelt Vec, Idx), Idx --> Vec
5156 if (match(Val
, m_ExtractElt(m_Specific(Vec
), m_Specific(Idx
))))
5162 /// Given operands for an ExtractValueInst, see if we can fold the result.
5163 /// If not, this returns null.
5164 static Value
*simplifyExtractValueInst(Value
*Agg
, ArrayRef
<unsigned> Idxs
,
5165 const SimplifyQuery
&, unsigned) {
5166 if (auto *CAgg
= dyn_cast
<Constant
>(Agg
))
5167 return ConstantFoldExtractValueInstruction(CAgg
, Idxs
);
5169 // extractvalue x, (insertvalue y, elt, n), n -> elt
5170 unsigned NumIdxs
= Idxs
.size();
5171 for (auto *IVI
= dyn_cast
<InsertValueInst
>(Agg
); IVI
!= nullptr;
5172 IVI
= dyn_cast
<InsertValueInst
>(IVI
->getAggregateOperand())) {
5173 ArrayRef
<unsigned> InsertValueIdxs
= IVI
->getIndices();
5174 unsigned NumInsertValueIdxs
= InsertValueIdxs
.size();
5175 unsigned NumCommonIdxs
= std::min(NumInsertValueIdxs
, NumIdxs
);
5176 if (InsertValueIdxs
.slice(0, NumCommonIdxs
) ==
5177 Idxs
.slice(0, NumCommonIdxs
)) {
5178 if (NumIdxs
== NumInsertValueIdxs
)
5179 return IVI
->getInsertedValueOperand();
5187 Value
*llvm::simplifyExtractValueInst(Value
*Agg
, ArrayRef
<unsigned> Idxs
,
5188 const SimplifyQuery
&Q
) {
5189 return ::simplifyExtractValueInst(Agg
, Idxs
, Q
, RecursionLimit
);
5192 /// Given operands for an ExtractElementInst, see if we can fold the result.
5193 /// If not, this returns null.
5194 static Value
*simplifyExtractElementInst(Value
*Vec
, Value
*Idx
,
5195 const SimplifyQuery
&Q
, unsigned) {
5196 auto *VecVTy
= cast
<VectorType
>(Vec
->getType());
5197 if (auto *CVec
= dyn_cast
<Constant
>(Vec
)) {
5198 if (auto *CIdx
= dyn_cast
<Constant
>(Idx
))
5199 return ConstantExpr::getExtractElement(CVec
, CIdx
);
5201 if (Q
.isUndefValue(Vec
))
5202 return UndefValue::get(VecVTy
->getElementType());
5205 // An undef extract index can be arbitrarily chosen to be an out-of-range
5206 // index value, which would result in the instruction being poison.
5207 if (Q
.isUndefValue(Idx
))
5208 return PoisonValue::get(VecVTy
->getElementType());
5210 // If extracting a specified index from the vector, see if we can recursively
5211 // find a previously computed scalar that was inserted into the vector.
5212 if (auto *IdxC
= dyn_cast
<ConstantInt
>(Idx
)) {
5213 // For fixed-length vector, fold into undef if index is out of bounds.
5214 unsigned MinNumElts
= VecVTy
->getElementCount().getKnownMinValue();
5215 if (isa
<FixedVectorType
>(VecVTy
) && IdxC
->getValue().uge(MinNumElts
))
5216 return PoisonValue::get(VecVTy
->getElementType());
5217 // Handle case where an element is extracted from a splat.
5218 if (IdxC
->getValue().ult(MinNumElts
))
5219 if (auto *Splat
= getSplatValue(Vec
))
5221 if (Value
*Elt
= findScalarElement(Vec
, IdxC
->getZExtValue()))
5224 // extractelt x, (insertelt y, elt, n), n -> elt
5225 // If the possibly-variable indices are trivially known to be equal
5226 // (because they are the same operand) then use the value that was
5227 // inserted directly.
5228 auto *IE
= dyn_cast
<InsertElementInst
>(Vec
);
5229 if (IE
&& IE
->getOperand(2) == Idx
)
5230 return IE
->getOperand(1);
5232 // The index is not relevant if our vector is a splat.
5233 if (Value
*Splat
= getSplatValue(Vec
))
5239 Value
*llvm::simplifyExtractElementInst(Value
*Vec
, Value
*Idx
,
5240 const SimplifyQuery
&Q
) {
5241 return ::simplifyExtractElementInst(Vec
, Idx
, Q
, RecursionLimit
);
5244 /// See if we can fold the given phi. If not, returns null.
5245 static Value
*simplifyPHINode(PHINode
*PN
, ArrayRef
<Value
*> IncomingValues
,
5246 const SimplifyQuery
&Q
) {
5247 // WARNING: no matter how worthwhile it may seem, we can not perform PHI CSE
5248 // here, because the PHI we may succeed simplifying to was not
5249 // def-reachable from the original PHI!
5251 // If all of the PHI's incoming values are the same then replace the PHI node
5252 // with the common value.
5253 Value
*CommonValue
= nullptr;
5254 bool HasUndefInput
= false;
5255 for (Value
*Incoming
: IncomingValues
) {
5256 // If the incoming value is the phi node itself, it can safely be skipped.
5259 if (Q
.isUndefValue(Incoming
)) {
5260 // Remember that we saw an undef value, but otherwise ignore them.
5261 HasUndefInput
= true;
5264 if (CommonValue
&& Incoming
!= CommonValue
)
5265 return nullptr; // Not the same, bail out.
5266 CommonValue
= Incoming
;
5269 // If CommonValue is null then all of the incoming values were either undef or
5270 // equal to the phi node itself.
5272 return UndefValue::get(PN
->getType());
5274 if (HasUndefInput
) {
5275 // If we have a PHI node like phi(X, undef, X), where X is defined by some
5276 // instruction, we cannot return X as the result of the PHI node unless it
5277 // dominates the PHI block.
5278 return valueDominatesPHI(CommonValue
, PN
, Q
.DT
) ? CommonValue
: nullptr;
5284 static Value
*simplifyCastInst(unsigned CastOpc
, Value
*Op
, Type
*Ty
,
5285 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
5286 if (auto *C
= dyn_cast
<Constant
>(Op
))
5287 return ConstantFoldCastOperand(CastOpc
, C
, Ty
, Q
.DL
);
5289 if (auto *CI
= dyn_cast
<CastInst
>(Op
)) {
5290 auto *Src
= CI
->getOperand(0);
5291 Type
*SrcTy
= Src
->getType();
5292 Type
*MidTy
= CI
->getType();
5294 if (Src
->getType() == Ty
) {
5295 auto FirstOp
= static_cast<Instruction::CastOps
>(CI
->getOpcode());
5296 auto SecondOp
= static_cast<Instruction::CastOps
>(CastOpc
);
5298 SrcTy
->isPtrOrPtrVectorTy() ? Q
.DL
.getIntPtrType(SrcTy
) : nullptr;
5300 MidTy
->isPtrOrPtrVectorTy() ? Q
.DL
.getIntPtrType(MidTy
) : nullptr;
5302 DstTy
->isPtrOrPtrVectorTy() ? Q
.DL
.getIntPtrType(DstTy
) : nullptr;
5303 if (CastInst::isEliminableCastPair(FirstOp
, SecondOp
, SrcTy
, MidTy
, DstTy
,
5304 SrcIntPtrTy
, MidIntPtrTy
,
5305 DstIntPtrTy
) == Instruction::BitCast
)
5311 if (CastOpc
== Instruction::BitCast
)
5312 if (Op
->getType() == Ty
)
5318 Value
*llvm::simplifyCastInst(unsigned CastOpc
, Value
*Op
, Type
*Ty
,
5319 const SimplifyQuery
&Q
) {
5320 return ::simplifyCastInst(CastOpc
, Op
, Ty
, Q
, RecursionLimit
);
5323 /// For the given destination element of a shuffle, peek through shuffles to
5324 /// match a root vector source operand that contains that element in the same
5325 /// vector lane (ie, the same mask index), so we can eliminate the shuffle(s).
5326 static Value
*foldIdentityShuffles(int DestElt
, Value
*Op0
, Value
*Op1
,
5327 int MaskVal
, Value
*RootVec
,
5328 unsigned MaxRecurse
) {
5332 // Bail out if any mask value is undefined. That kind of shuffle may be
5333 // simplified further based on demanded bits or other folds.
5337 // The mask value chooses which source operand we need to look at next.
5338 int InVecNumElts
= cast
<FixedVectorType
>(Op0
->getType())->getNumElements();
5339 int RootElt
= MaskVal
;
5340 Value
*SourceOp
= Op0
;
5341 if (MaskVal
>= InVecNumElts
) {
5342 RootElt
= MaskVal
- InVecNumElts
;
5346 // If the source operand is a shuffle itself, look through it to find the
5347 // matching root vector.
5348 if (auto *SourceShuf
= dyn_cast
<ShuffleVectorInst
>(SourceOp
)) {
5349 return foldIdentityShuffles(
5350 DestElt
, SourceShuf
->getOperand(0), SourceShuf
->getOperand(1),
5351 SourceShuf
->getMaskValue(RootElt
), RootVec
, MaxRecurse
);
5354 // TODO: Look through bitcasts? What if the bitcast changes the vector element
5357 // The source operand is not a shuffle. Initialize the root vector value for
5358 // this shuffle if that has not been done yet.
5362 // Give up as soon as a source operand does not match the existing root value.
5363 if (RootVec
!= SourceOp
)
5366 // The element must be coming from the same lane in the source vector
5367 // (although it may have crossed lanes in intermediate shuffles).
5368 if (RootElt
!= DestElt
)
5374 static Value
*simplifyShuffleVectorInst(Value
*Op0
, Value
*Op1
,
5375 ArrayRef
<int> Mask
, Type
*RetTy
,
5376 const SimplifyQuery
&Q
,
5377 unsigned MaxRecurse
) {
5378 if (all_of(Mask
, [](int Elem
) { return Elem
== PoisonMaskElem
; }))
5379 return PoisonValue::get(RetTy
);
5381 auto *InVecTy
= cast
<VectorType
>(Op0
->getType());
5382 unsigned MaskNumElts
= Mask
.size();
5383 ElementCount InVecEltCount
= InVecTy
->getElementCount();
5385 bool Scalable
= InVecEltCount
.isScalable();
5387 SmallVector
<int, 32> Indices
;
5388 Indices
.assign(Mask
.begin(), Mask
.end());
5390 // Canonicalization: If mask does not select elements from an input vector,
5391 // replace that input vector with poison.
5393 bool MaskSelects0
= false, MaskSelects1
= false;
5394 unsigned InVecNumElts
= InVecEltCount
.getKnownMinValue();
5395 for (unsigned i
= 0; i
!= MaskNumElts
; ++i
) {
5396 if (Indices
[i
] == -1)
5398 if ((unsigned)Indices
[i
] < InVecNumElts
)
5399 MaskSelects0
= true;
5401 MaskSelects1
= true;
5404 Op0
= PoisonValue::get(InVecTy
);
5406 Op1
= PoisonValue::get(InVecTy
);
5409 auto *Op0Const
= dyn_cast
<Constant
>(Op0
);
5410 auto *Op1Const
= dyn_cast
<Constant
>(Op1
);
5412 // If all operands are constant, constant fold the shuffle. This
5413 // transformation depends on the value of the mask which is not known at
5414 // compile time for scalable vectors
5415 if (Op0Const
&& Op1Const
)
5416 return ConstantExpr::getShuffleVector(Op0Const
, Op1Const
, Mask
);
5418 // Canonicalization: if only one input vector is constant, it shall be the
5419 // second one. This transformation depends on the value of the mask which
5420 // is not known at compile time for scalable vectors
5421 if (!Scalable
&& Op0Const
&& !Op1Const
) {
5422 std::swap(Op0
, Op1
);
5423 ShuffleVectorInst::commuteShuffleMask(Indices
,
5424 InVecEltCount
.getKnownMinValue());
5427 // A splat of an inserted scalar constant becomes a vector constant:
5428 // shuf (inselt ?, C, IndexC), undef, <IndexC, IndexC...> --> <C, C...>
5429 // NOTE: We may have commuted above, so analyze the updated Indices, not the
5430 // original mask constant.
5431 // NOTE: This transformation depends on the value of the mask which is not
5432 // known at compile time for scalable vectors
5434 ConstantInt
*IndexC
;
5435 if (!Scalable
&& match(Op0
, m_InsertElt(m_Value(), m_Constant(C
),
5436 m_ConstantInt(IndexC
)))) {
5437 // Match a splat shuffle mask of the insert index allowing undef elements.
5438 int InsertIndex
= IndexC
->getZExtValue();
5439 if (all_of(Indices
, [InsertIndex
](int MaskElt
) {
5440 return MaskElt
== InsertIndex
|| MaskElt
== -1;
5442 assert(isa
<UndefValue
>(Op1
) && "Expected undef operand 1 for splat");
5444 // Shuffle mask poisons become poison constant result elements.
5445 SmallVector
<Constant
*, 16> VecC(MaskNumElts
, C
);
5446 for (unsigned i
= 0; i
!= MaskNumElts
; ++i
)
5447 if (Indices
[i
] == -1)
5448 VecC
[i
] = PoisonValue::get(C
->getType());
5449 return ConstantVector::get(VecC
);
5453 // A shuffle of a splat is always the splat itself. Legal if the shuffle's
5454 // value type is same as the input vectors' type.
5455 if (auto *OpShuf
= dyn_cast
<ShuffleVectorInst
>(Op0
))
5456 if (Q
.isUndefValue(Op1
) && RetTy
== InVecTy
&&
5457 all_equal(OpShuf
->getShuffleMask()))
5460 // All remaining transformation depend on the value of the mask, which is
5461 // not known at compile time for scalable vectors.
5465 // Don't fold a shuffle with undef mask elements. This may get folded in a
5466 // better way using demanded bits or other analysis.
5467 // TODO: Should we allow this?
5468 if (is_contained(Indices
, -1))
5471 // Check if every element of this shuffle can be mapped back to the
5472 // corresponding element of a single root vector. If so, we don't need this
5473 // shuffle. This handles simple identity shuffles as well as chains of
5474 // shuffles that may widen/narrow and/or move elements across lanes and back.
5475 Value
*RootVec
= nullptr;
5476 for (unsigned i
= 0; i
!= MaskNumElts
; ++i
) {
5477 // Note that recursion is limited for each vector element, so if any element
5478 // exceeds the limit, this will fail to simplify.
5480 foldIdentityShuffles(i
, Op0
, Op1
, Indices
[i
], RootVec
, MaxRecurse
);
5482 // We can't replace a widening/narrowing shuffle with one of its operands.
5483 if (!RootVec
|| RootVec
->getType() != RetTy
)
5489 /// Given operands for a ShuffleVectorInst, fold the result or return null.
5490 Value
*llvm::simplifyShuffleVectorInst(Value
*Op0
, Value
*Op1
,
5491 ArrayRef
<int> Mask
, Type
*RetTy
,
5492 const SimplifyQuery
&Q
) {
5493 return ::simplifyShuffleVectorInst(Op0
, Op1
, Mask
, RetTy
, Q
, RecursionLimit
);
5496 static Constant
*foldConstant(Instruction::UnaryOps Opcode
, Value
*&Op
,
5497 const SimplifyQuery
&Q
) {
5498 if (auto *C
= dyn_cast
<Constant
>(Op
))
5499 return ConstantFoldUnaryOpOperand(Opcode
, C
, Q
.DL
);
5503 /// Given the operand for an FNeg, see if we can fold the result. If not, this
5505 static Value
*simplifyFNegInst(Value
*Op
, FastMathFlags FMF
,
5506 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
5507 if (Constant
*C
= foldConstant(Instruction::FNeg
, Op
, Q
))
5511 // fneg (fneg X) ==> X
5512 if (match(Op
, m_FNeg(m_Value(X
))))
5518 Value
*llvm::simplifyFNegInst(Value
*Op
, FastMathFlags FMF
,
5519 const SimplifyQuery
&Q
) {
5520 return ::simplifyFNegInst(Op
, FMF
, Q
, RecursionLimit
);
5523 /// Try to propagate existing NaN values when possible. If not, replace the
5524 /// constant or elements in the constant with a canonical NaN.
5525 static Constant
*propagateNaN(Constant
*In
) {
5526 Type
*Ty
= In
->getType();
5527 if (auto *VecTy
= dyn_cast
<FixedVectorType
>(Ty
)) {
5528 unsigned NumElts
= VecTy
->getNumElements();
5529 SmallVector
<Constant
*, 32> NewC(NumElts
);
5530 for (unsigned i
= 0; i
!= NumElts
; ++i
) {
5531 Constant
*EltC
= In
->getAggregateElement(i
);
5532 // Poison elements propagate. NaN propagates except signaling is quieted.
5533 // Replace unknown or undef elements with canonical NaN.
5534 if (EltC
&& isa
<PoisonValue
>(EltC
))
5536 else if (EltC
&& EltC
->isNaN())
5537 NewC
[i
] = ConstantFP::get(
5538 EltC
->getType(), cast
<ConstantFP
>(EltC
)->getValue().makeQuiet());
5540 NewC
[i
] = ConstantFP::getNaN(VecTy
->getElementType());
5542 return ConstantVector::get(NewC
);
5545 // If it is not a fixed vector, but not a simple NaN either, return a
5548 return ConstantFP::getNaN(Ty
);
5550 // If we known this is a NaN, and it's scalable vector, we must have a splat
5551 // on our hands. Grab that before splatting a QNaN constant.
5552 if (isa
<ScalableVectorType
>(Ty
)) {
5553 auto *Splat
= In
->getSplatValue();
5554 assert(Splat
&& Splat
->isNaN() &&
5555 "Found a scalable-vector NaN but not a splat");
5559 // Propagate an existing QNaN constant. If it is an SNaN, make it quiet, but
5560 // preserve the sign/payload.
5561 return ConstantFP::get(Ty
, cast
<ConstantFP
>(In
)->getValue().makeQuiet());
5564 /// Perform folds that are common to any floating-point operation. This implies
5565 /// transforms based on poison/undef/NaN because the operation itself makes no
5566 /// difference to the result.
5567 static Constant
*simplifyFPOp(ArrayRef
<Value
*> Ops
, FastMathFlags FMF
,
5568 const SimplifyQuery
&Q
,
5569 fp::ExceptionBehavior ExBehavior
,
5570 RoundingMode Rounding
) {
5571 // Poison is independent of anything else. It always propagates from an
5572 // operand to a math result.
5573 if (any_of(Ops
, [](Value
*V
) { return match(V
, m_Poison()); }))
5574 return PoisonValue::get(Ops
[0]->getType());
5576 for (Value
*V
: Ops
) {
5577 bool IsNan
= match(V
, m_NaN());
5578 bool IsInf
= match(V
, m_Inf());
5579 bool IsUndef
= Q
.isUndefValue(V
);
5581 // If this operation has 'nnan' or 'ninf' and at least 1 disallowed operand
5582 // (an undef operand can be chosen to be Nan/Inf), then the result of
5583 // this operation is poison.
5584 if (FMF
.noNaNs() && (IsNan
|| IsUndef
))
5585 return PoisonValue::get(V
->getType());
5586 if (FMF
.noInfs() && (IsInf
|| IsUndef
))
5587 return PoisonValue::get(V
->getType());
5589 if (isDefaultFPEnvironment(ExBehavior
, Rounding
)) {
5590 // Undef does not propagate because undef means that all bits can take on
5591 // any value. If this is undef * NaN for example, then the result values
5592 // (at least the exponent bits) are limited. Assume the undef is a
5593 // canonical NaN and propagate that.
5595 return ConstantFP::getNaN(V
->getType());
5597 return propagateNaN(cast
<Constant
>(V
));
5598 } else if (ExBehavior
!= fp::ebStrict
) {
5600 return propagateNaN(cast
<Constant
>(V
));
5606 /// Given operands for an FAdd, see if we can fold the result. If not, this
5609 simplifyFAddInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5610 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5611 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5612 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5613 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5614 if (Constant
*C
= foldOrCommuteConstant(Instruction::FAdd
, Op0
, Op1
, Q
))
5617 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5621 // With strict/constrained FP, we have these possible edge cases that do
5622 // not simplify to Op0:
5623 // fadd SNaN, -0.0 --> QNaN
5624 // fadd +0.0, -0.0 --> -0.0 (but only with round toward negative)
5625 if (canIgnoreSNaN(ExBehavior
, FMF
) &&
5626 (!canRoundingModeBe(Rounding
, RoundingMode::TowardNegative
) ||
5627 FMF
.noSignedZeros()))
5628 if (match(Op1
, m_NegZeroFP()))
5631 // fadd X, 0 ==> X, when we know X is not -0
5632 if (canIgnoreSNaN(ExBehavior
, FMF
))
5633 if (match(Op1
, m_PosZeroFP()) &&
5634 (FMF
.noSignedZeros() || cannotBeNegativeZero(Op0
, Q
.DL
, Q
.TLI
)))
5637 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5641 // With nnan: X + {+/-}Inf --> {+/-}Inf
5642 if (match(Op1
, m_Inf()))
5645 // With nnan: -X + X --> 0.0 (and commuted variant)
5646 // We don't have to explicitly exclude infinities (ninf): INF + -INF == NaN.
5647 // Negative zeros are allowed because we always end up with positive zero:
5648 // X = -0.0: (-0.0 - (-0.0)) + (-0.0) == ( 0.0) + (-0.0) == 0.0
5649 // X = -0.0: ( 0.0 - (-0.0)) + (-0.0) == ( 0.0) + (-0.0) == 0.0
5650 // X = 0.0: (-0.0 - ( 0.0)) + ( 0.0) == (-0.0) + ( 0.0) == 0.0
5651 // X = 0.0: ( 0.0 - ( 0.0)) + ( 0.0) == ( 0.0) + ( 0.0) == 0.0
5652 if (match(Op0
, m_FSub(m_AnyZeroFP(), m_Specific(Op1
))) ||
5653 match(Op1
, m_FSub(m_AnyZeroFP(), m_Specific(Op0
))))
5654 return ConstantFP::getZero(Op0
->getType());
5656 if (match(Op0
, m_FNeg(m_Specific(Op1
))) ||
5657 match(Op1
, m_FNeg(m_Specific(Op0
))))
5658 return ConstantFP::getZero(Op0
->getType());
5661 // (X - Y) + Y --> X
5662 // Y + (X - Y) --> X
5664 if (FMF
.noSignedZeros() && FMF
.allowReassoc() &&
5665 (match(Op0
, m_FSub(m_Value(X
), m_Specific(Op1
))) ||
5666 match(Op1
, m_FSub(m_Value(X
), m_Specific(Op0
)))))
5672 /// Given operands for an FSub, see if we can fold the result. If not, this
5675 simplifyFSubInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5676 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5677 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5678 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5679 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5680 if (Constant
*C
= foldOrCommuteConstant(Instruction::FSub
, Op0
, Op1
, Q
))
5683 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5687 if (canIgnoreSNaN(ExBehavior
, FMF
) &&
5688 (!canRoundingModeBe(Rounding
, RoundingMode::TowardNegative
) ||
5689 FMF
.noSignedZeros()))
5690 if (match(Op1
, m_PosZeroFP()))
5693 // fsub X, -0 ==> X, when we know X is not -0
5694 if (canIgnoreSNaN(ExBehavior
, FMF
))
5695 if (match(Op1
, m_NegZeroFP()) &&
5696 (FMF
.noSignedZeros() || cannotBeNegativeZero(Op0
, Q
.DL
, Q
.TLI
)))
5699 // fsub -0.0, (fsub -0.0, X) ==> X
5700 // fsub -0.0, (fneg X) ==> X
5702 if (canIgnoreSNaN(ExBehavior
, FMF
))
5703 if (match(Op0
, m_NegZeroFP()) && match(Op1
, m_FNeg(m_Value(X
))))
5706 // fsub 0.0, (fsub 0.0, X) ==> X if signed zeros are ignored.
5707 // fsub 0.0, (fneg X) ==> X if signed zeros are ignored.
5708 if (canIgnoreSNaN(ExBehavior
, FMF
))
5709 if (FMF
.noSignedZeros() && match(Op0
, m_AnyZeroFP()) &&
5710 (match(Op1
, m_FSub(m_AnyZeroFP(), m_Value(X
))) ||
5711 match(Op1
, m_FNeg(m_Value(X
)))))
5714 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5718 // fsub nnan x, x ==> 0.0
5720 return Constant::getNullValue(Op0
->getType());
5722 // With nnan: {+/-}Inf - X --> {+/-}Inf
5723 if (match(Op0
, m_Inf()))
5726 // With nnan: X - {+/-}Inf --> {-/+}Inf
5727 if (match(Op1
, m_Inf()))
5728 return foldConstant(Instruction::FNeg
, Op1
, Q
);
5731 // Y - (Y - X) --> X
5732 // (X + Y) - Y --> X
5733 if (FMF
.noSignedZeros() && FMF
.allowReassoc() &&
5734 (match(Op1
, m_FSub(m_Specific(Op0
), m_Value(X
))) ||
5735 match(Op0
, m_c_FAdd(m_Specific(Op1
), m_Value(X
)))))
5741 static Value
*simplifyFMAFMul(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5742 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5743 fp::ExceptionBehavior ExBehavior
,
5744 RoundingMode Rounding
) {
5745 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5748 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5751 // Canonicalize special constants as operand 1.
5752 if (match(Op0
, m_FPOne()) || match(Op0
, m_AnyZeroFP()))
5753 std::swap(Op0
, Op1
);
5756 if (match(Op1
, m_FPOne()))
5759 if (match(Op1
, m_AnyZeroFP())) {
5760 // X * 0.0 --> 0.0 (with nnan and nsz)
5761 if (FMF
.noNaNs() && FMF
.noSignedZeros())
5762 return ConstantFP::getZero(Op0
->getType());
5764 // +normal number * (-)0.0 --> (-)0.0
5765 if (isKnownNeverInfOrNaN(Op0
, Q
.DL
, Q
.TLI
, 0, Q
.AC
, Q
.CxtI
, Q
.DT
) &&
5766 // TODO: Check SignBit from computeKnownFPClass when it's more complete.
5767 SignBitMustBeZero(Op0
, Q
.DL
, Q
.TLI
))
5771 // sqrt(X) * sqrt(X) --> X, if we can:
5772 // 1. Remove the intermediate rounding (reassociate).
5773 // 2. Ignore non-zero negative numbers because sqrt would produce NAN.
5774 // 3. Ignore -0.0 because sqrt(-0.0) == -0.0, but -0.0 * -0.0 == 0.0.
5776 if (Op0
== Op1
&& match(Op0
, m_Sqrt(m_Value(X
))) && FMF
.allowReassoc() &&
5777 FMF
.noNaNs() && FMF
.noSignedZeros())
5783 /// Given the operands for an FMul, see if we can fold the result
5785 simplifyFMulInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5786 const SimplifyQuery
&Q
, unsigned MaxRecurse
,
5787 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5788 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5789 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5790 if (Constant
*C
= foldOrCommuteConstant(Instruction::FMul
, Op0
, Op1
, Q
))
5793 // Now apply simplifications that do not require rounding.
5794 return simplifyFMAFMul(Op0
, Op1
, FMF
, Q
, MaxRecurse
, ExBehavior
, Rounding
);
5797 Value
*llvm::simplifyFAddInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5798 const SimplifyQuery
&Q
,
5799 fp::ExceptionBehavior ExBehavior
,
5800 RoundingMode Rounding
) {
5801 return ::simplifyFAddInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5805 Value
*llvm::simplifyFSubInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5806 const SimplifyQuery
&Q
,
5807 fp::ExceptionBehavior ExBehavior
,
5808 RoundingMode Rounding
) {
5809 return ::simplifyFSubInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5813 Value
*llvm::simplifyFMulInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5814 const SimplifyQuery
&Q
,
5815 fp::ExceptionBehavior ExBehavior
,
5816 RoundingMode Rounding
) {
5817 return ::simplifyFMulInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5821 Value
*llvm::simplifyFMAFMul(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5822 const SimplifyQuery
&Q
,
5823 fp::ExceptionBehavior ExBehavior
,
5824 RoundingMode Rounding
) {
5825 return ::simplifyFMAFMul(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5830 simplifyFDivInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5831 const SimplifyQuery
&Q
, unsigned,
5832 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5833 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5834 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5835 if (Constant
*C
= foldOrCommuteConstant(Instruction::FDiv
, Op0
, Op1
, Q
))
5838 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5841 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5845 if (match(Op1
, m_FPOne()))
5849 // Requires that NaNs are off (X could be zero) and signed zeroes are
5850 // ignored (X could be positive or negative, so the output sign is unknown).
5851 if (FMF
.noNaNs() && FMF
.noSignedZeros() && match(Op0
, m_AnyZeroFP()))
5852 return ConstantFP::getZero(Op0
->getType());
5855 // X / X -> 1.0 is legal when NaNs are ignored.
5856 // We can ignore infinities because INF/INF is NaN.
5858 return ConstantFP::get(Op0
->getType(), 1.0);
5860 // (X * Y) / Y --> X if we can reassociate to the above form.
5862 if (FMF
.allowReassoc() && match(Op0
, m_c_FMul(m_Value(X
), m_Specific(Op1
))))
5865 // -X / X -> -1.0 and
5866 // X / -X -> -1.0 are legal when NaNs are ignored.
5867 // We can ignore signed zeros because +-0.0/+-0.0 is NaN and ignored.
5868 if (match(Op0
, m_FNegNSZ(m_Specific(Op1
))) ||
5869 match(Op1
, m_FNegNSZ(m_Specific(Op0
))))
5870 return ConstantFP::get(Op0
->getType(), -1.0);
5872 // nnan ninf X / [-]0.0 -> poison
5873 if (FMF
.noInfs() && match(Op1
, m_AnyZeroFP()))
5874 return PoisonValue::get(Op1
->getType());
5880 Value
*llvm::simplifyFDivInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5881 const SimplifyQuery
&Q
,
5882 fp::ExceptionBehavior ExBehavior
,
5883 RoundingMode Rounding
) {
5884 return ::simplifyFDivInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5889 simplifyFRemInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5890 const SimplifyQuery
&Q
, unsigned,
5891 fp::ExceptionBehavior ExBehavior
= fp::ebIgnore
,
5892 RoundingMode Rounding
= RoundingMode::NearestTiesToEven
) {
5893 if (isDefaultFPEnvironment(ExBehavior
, Rounding
))
5894 if (Constant
*C
= foldOrCommuteConstant(Instruction::FRem
, Op0
, Op1
, Q
))
5897 if (Constant
*C
= simplifyFPOp({Op0
, Op1
}, FMF
, Q
, ExBehavior
, Rounding
))
5900 if (!isDefaultFPEnvironment(ExBehavior
, Rounding
))
5903 // Unlike fdiv, the result of frem always matches the sign of the dividend.
5904 // The constant match may include undef elements in a vector, so return a full
5905 // zero constant as the result.
5908 if (match(Op0
, m_PosZeroFP()))
5909 return ConstantFP::getZero(Op0
->getType());
5911 if (match(Op0
, m_NegZeroFP()))
5912 return ConstantFP::getNegativeZero(Op0
->getType());
5918 Value
*llvm::simplifyFRemInst(Value
*Op0
, Value
*Op1
, FastMathFlags FMF
,
5919 const SimplifyQuery
&Q
,
5920 fp::ExceptionBehavior ExBehavior
,
5921 RoundingMode Rounding
) {
5922 return ::simplifyFRemInst(Op0
, Op1
, FMF
, Q
, RecursionLimit
, ExBehavior
,
5926 //=== Helper functions for higher up the class hierarchy.
5928 /// Given the operand for a UnaryOperator, see if we can fold the result.
5929 /// If not, this returns null.
5930 static Value
*simplifyUnOp(unsigned Opcode
, Value
*Op
, const SimplifyQuery
&Q
,
5931 unsigned MaxRecurse
) {
5933 case Instruction::FNeg
:
5934 return simplifyFNegInst(Op
, FastMathFlags(), Q
, MaxRecurse
);
5936 llvm_unreachable("Unexpected opcode");
5940 /// Given the operand for a UnaryOperator, see if we can fold the result.
5941 /// If not, this returns null.
5942 /// Try to use FastMathFlags when folding the result.
5943 static Value
*simplifyFPUnOp(unsigned Opcode
, Value
*Op
,
5944 const FastMathFlags
&FMF
, const SimplifyQuery
&Q
,
5945 unsigned MaxRecurse
) {
5947 case Instruction::FNeg
:
5948 return simplifyFNegInst(Op
, FMF
, Q
, MaxRecurse
);
5950 return simplifyUnOp(Opcode
, Op
, Q
, MaxRecurse
);
5954 Value
*llvm::simplifyUnOp(unsigned Opcode
, Value
*Op
, const SimplifyQuery
&Q
) {
5955 return ::simplifyUnOp(Opcode
, Op
, Q
, RecursionLimit
);
5958 Value
*llvm::simplifyUnOp(unsigned Opcode
, Value
*Op
, FastMathFlags FMF
,
5959 const SimplifyQuery
&Q
) {
5960 return ::simplifyFPUnOp(Opcode
, Op
, FMF
, Q
, RecursionLimit
);
5963 /// Given operands for a BinaryOperator, see if we can fold the result.
5964 /// If not, this returns null.
5965 static Value
*simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
5966 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
5968 case Instruction::Add
:
5969 return simplifyAddInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
5971 case Instruction::Sub
:
5972 return simplifySubInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
5974 case Instruction::Mul
:
5975 return simplifyMulInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
5977 case Instruction::SDiv
:
5978 return simplifySDivInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
5979 case Instruction::UDiv
:
5980 return simplifyUDivInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
5981 case Instruction::SRem
:
5982 return simplifySRemInst(LHS
, RHS
, Q
, MaxRecurse
);
5983 case Instruction::URem
:
5984 return simplifyURemInst(LHS
, RHS
, Q
, MaxRecurse
);
5985 case Instruction::Shl
:
5986 return simplifyShlInst(LHS
, RHS
, /* IsNSW */ false, /* IsNUW */ false, Q
,
5988 case Instruction::LShr
:
5989 return simplifyLShrInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
5990 case Instruction::AShr
:
5991 return simplifyAShrInst(LHS
, RHS
, /* IsExact */ false, Q
, MaxRecurse
);
5992 case Instruction::And
:
5993 return simplifyAndInst(LHS
, RHS
, Q
, MaxRecurse
);
5994 case Instruction::Or
:
5995 return simplifyOrInst(LHS
, RHS
, Q
, MaxRecurse
);
5996 case Instruction::Xor
:
5997 return simplifyXorInst(LHS
, RHS
, Q
, MaxRecurse
);
5998 case Instruction::FAdd
:
5999 return simplifyFAddInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6000 case Instruction::FSub
:
6001 return simplifyFSubInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6002 case Instruction::FMul
:
6003 return simplifyFMulInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6004 case Instruction::FDiv
:
6005 return simplifyFDivInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6006 case Instruction::FRem
:
6007 return simplifyFRemInst(LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6009 llvm_unreachable("Unexpected opcode");
6013 /// Given operands for a BinaryOperator, see if we can fold the result.
6014 /// If not, this returns null.
6015 /// Try to use FastMathFlags when folding the result.
6016 static Value
*simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
6017 const FastMathFlags
&FMF
, const SimplifyQuery
&Q
,
6018 unsigned MaxRecurse
) {
6020 case Instruction::FAdd
:
6021 return simplifyFAddInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6022 case Instruction::FSub
:
6023 return simplifyFSubInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6024 case Instruction::FMul
:
6025 return simplifyFMulInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6026 case Instruction::FDiv
:
6027 return simplifyFDivInst(LHS
, RHS
, FMF
, Q
, MaxRecurse
);
6029 return simplifyBinOp(Opcode
, LHS
, RHS
, Q
, MaxRecurse
);
6033 Value
*llvm::simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
6034 const SimplifyQuery
&Q
) {
6035 return ::simplifyBinOp(Opcode
, LHS
, RHS
, Q
, RecursionLimit
);
6038 Value
*llvm::simplifyBinOp(unsigned Opcode
, Value
*LHS
, Value
*RHS
,
6039 FastMathFlags FMF
, const SimplifyQuery
&Q
) {
6040 return ::simplifyBinOp(Opcode
, LHS
, RHS
, FMF
, Q
, RecursionLimit
);
6043 /// Given operands for a CmpInst, see if we can fold the result.
6044 static Value
*simplifyCmpInst(unsigned Predicate
, Value
*LHS
, Value
*RHS
,
6045 const SimplifyQuery
&Q
, unsigned MaxRecurse
) {
6046 if (CmpInst::isIntPredicate((CmpInst::Predicate
)Predicate
))
6047 return simplifyICmpInst(Predicate
, LHS
, RHS
, Q
, MaxRecurse
);
6048 return simplifyFCmpInst(Predicate
, LHS
, RHS
, FastMathFlags(), Q
, MaxRecurse
);
6051 Value
*llvm::simplifyCmpInst(unsigned Predicate
, Value
*LHS
, Value
*RHS
,
6052 const SimplifyQuery
&Q
) {
6053 return ::simplifyCmpInst(Predicate
, LHS
, RHS
, Q
, RecursionLimit
);
6056 static bool isIdempotent(Intrinsic::ID ID
) {
6061 // Unary idempotent: f(f(x)) = f(x)
6062 case Intrinsic::fabs
:
6063 case Intrinsic::floor
:
6064 case Intrinsic::ceil
:
6065 case Intrinsic::trunc
:
6066 case Intrinsic::rint
:
6067 case Intrinsic::nearbyint
:
6068 case Intrinsic::round
:
6069 case Intrinsic::roundeven
:
6070 case Intrinsic::canonicalize
:
6071 case Intrinsic::arithmetic_fence
:
6076 /// Return true if the intrinsic rounds a floating-point value to an integral
6077 /// floating-point value (not an integer type).
6078 static bool removesFPFraction(Intrinsic::ID ID
) {
6083 case Intrinsic::floor
:
6084 case Intrinsic::ceil
:
6085 case Intrinsic::trunc
:
6086 case Intrinsic::rint
:
6087 case Intrinsic::nearbyint
:
6088 case Intrinsic::round
:
6089 case Intrinsic::roundeven
:
6094 static Value
*simplifyRelativeLoad(Constant
*Ptr
, Constant
*Offset
,
6095 const DataLayout
&DL
) {
6096 GlobalValue
*PtrSym
;
6098 if (!IsConstantOffsetFromGlobal(Ptr
, PtrSym
, PtrOffset
, DL
))
6101 Type
*Int32Ty
= Type::getInt32Ty(Ptr
->getContext());
6103 auto *OffsetConstInt
= dyn_cast
<ConstantInt
>(Offset
);
6104 if (!OffsetConstInt
|| OffsetConstInt
->getBitWidth() > 64)
6107 APInt OffsetInt
= OffsetConstInt
->getValue().sextOrTrunc(
6108 DL
.getIndexTypeSizeInBits(Ptr
->getType()));
6109 if (OffsetInt
.srem(4) != 0)
6112 Constant
*Loaded
= ConstantFoldLoadFromConstPtr(Ptr
, Int32Ty
, OffsetInt
, DL
);
6116 auto *LoadedCE
= dyn_cast
<ConstantExpr
>(Loaded
);
6120 if (LoadedCE
->getOpcode() == Instruction::Trunc
) {
6121 LoadedCE
= dyn_cast
<ConstantExpr
>(LoadedCE
->getOperand(0));
6126 if (LoadedCE
->getOpcode() != Instruction::Sub
)
6129 auto *LoadedLHS
= dyn_cast
<ConstantExpr
>(LoadedCE
->getOperand(0));
6130 if (!LoadedLHS
|| LoadedLHS
->getOpcode() != Instruction::PtrToInt
)
6132 auto *LoadedLHSPtr
= LoadedLHS
->getOperand(0);
6134 Constant
*LoadedRHS
= LoadedCE
->getOperand(1);
6135 GlobalValue
*LoadedRHSSym
;
6136 APInt LoadedRHSOffset
;
6137 if (!IsConstantOffsetFromGlobal(LoadedRHS
, LoadedRHSSym
, LoadedRHSOffset
,
6139 PtrSym
!= LoadedRHSSym
|| PtrOffset
!= LoadedRHSOffset
)
6142 return LoadedLHSPtr
;
6145 // TODO: Need to pass in FastMathFlags
6146 static Value
*simplifyLdexp(Value
*Op0
, Value
*Op1
, const SimplifyQuery
&Q
,
6148 // ldexp(poison, x) -> poison
6149 // ldexp(x, poison) -> poison
6150 if (isa
<PoisonValue
>(Op0
) || isa
<PoisonValue
>(Op1
))
6153 // ldexp(undef, x) -> nan
6154 if (Q
.isUndefValue(Op0
))
6155 return ConstantFP::getNaN(Op0
->getType());
6158 // TODO: Could insert a canonicalize for strict
6160 // ldexp(x, undef) -> x
6161 if (Q
.isUndefValue(Op1
))
6165 const APFloat
*C
= nullptr;
6166 match(Op0
, PatternMatch::m_APFloat(C
));
6168 // These cases should be safe, even with strictfp.
6169 // ldexp(0.0, x) -> 0.0
6170 // ldexp(-0.0, x) -> -0.0
6171 // ldexp(inf, x) -> inf
6172 // ldexp(-inf, x) -> -inf
6173 if (C
&& (C
->isZero() || C
->isInfinity()))
6176 // These are canonicalization dropping, could do it if we knew how we could
6177 // ignore denormal flushes and target handling of nan payload bits.
6181 // TODO: Could quiet this with strictfp if the exception mode isn't strict.
6182 if (C
&& C
->isNaN())
6183 return ConstantFP::get(Op0
->getType(), C
->makeQuiet());
6187 // TODO: Could fold this if we know the exception mode isn't
6188 // strict, we know the denormal mode and other target modes.
6189 if (match(Op1
, PatternMatch::m_ZeroInt()))
6195 static Value
*simplifyUnaryIntrinsic(Function
*F
, Value
*Op0
,
6196 const SimplifyQuery
&Q
,
6197 const CallBase
*Call
) {
6198 // Idempotent functions return the same result when called repeatedly.
6199 Intrinsic::ID IID
= F
->getIntrinsicID();
6200 if (isIdempotent(IID
))
6201 if (auto *II
= dyn_cast
<IntrinsicInst
>(Op0
))
6202 if (II
->getIntrinsicID() == IID
)
6205 if (removesFPFraction(IID
)) {
6206 // Converting from int or calling a rounding function always results in a
6207 // finite integral number or infinity. For those inputs, rounding functions
6208 // always return the same value, so the (2nd) rounding is eliminated. Ex:
6209 // floor (sitofp x) -> sitofp x
6210 // round (ceil x) -> ceil x
6211 auto *II
= dyn_cast
<IntrinsicInst
>(Op0
);
6212 if ((II
&& removesFPFraction(II
->getIntrinsicID())) ||
6213 match(Op0
, m_SIToFP(m_Value())) || match(Op0
, m_UIToFP(m_Value())))
6219 case Intrinsic::fabs
:
6220 if (SignBitMustBeZero(Op0
, Q
.DL
, Q
.TLI
))
6223 case Intrinsic::bswap
:
6224 // bswap(bswap(x)) -> x
6225 if (match(Op0
, m_BSwap(m_Value(X
))))
6228 case Intrinsic::bitreverse
:
6229 // bitreverse(bitreverse(x)) -> x
6230 if (match(Op0
, m_BitReverse(m_Value(X
))))
6233 case Intrinsic::ctpop
: {
6234 // ctpop(X) -> 1 iff X is non-zero power of 2.
6235 if (isKnownToBeAPowerOfTwo(Op0
, Q
.DL
, /*OrZero*/ false, 0, Q
.AC
, Q
.CxtI
,
6237 return ConstantInt::get(Op0
->getType(), 1);
6238 // If everything but the lowest bit is zero, that bit is the pop-count. Ex:
6239 // ctpop(and X, 1) --> and X, 1
6240 unsigned BitWidth
= Op0
->getType()->getScalarSizeInBits();
6241 if (MaskedValueIsZero(Op0
, APInt::getHighBitsSet(BitWidth
, BitWidth
- 1),
6246 case Intrinsic::exp
:
6248 if (Call
->hasAllowReassoc() &&
6249 match(Op0
, m_Intrinsic
<Intrinsic::log
>(m_Value(X
))))
6252 case Intrinsic::exp2
:
6253 // exp2(log2(x)) -> x
6254 if (Call
->hasAllowReassoc() &&
6255 match(Op0
, m_Intrinsic
<Intrinsic::log2
>(m_Value(X
))))
6258 case Intrinsic::exp10
:
6259 // exp10(log10(x)) -> x
6260 if (Call
->hasAllowReassoc() &&
6261 match(Op0
, m_Intrinsic
<Intrinsic::log10
>(m_Value(X
))))
6264 case Intrinsic::log
:
6266 if (Call
->hasAllowReassoc() &&
6267 match(Op0
, m_Intrinsic
<Intrinsic::exp
>(m_Value(X
))))
6270 case Intrinsic::log2
:
6271 // log2(exp2(x)) -> x
6272 if (Call
->hasAllowReassoc() &&
6273 (match(Op0
, m_Intrinsic
<Intrinsic::exp2
>(m_Value(X
))) ||
6275 m_Intrinsic
<Intrinsic::pow
>(m_SpecificFP(2.0), m_Value(X
)))))
6278 case Intrinsic::log10
:
6279 // log10(pow(10.0, x)) -> x
6280 // log10(exp10(x)) -> x
6281 if (Call
->hasAllowReassoc() &&
6282 (match(Op0
, m_Intrinsic
<Intrinsic::exp10
>(m_Value(X
))) ||
6284 m_Intrinsic
<Intrinsic::pow
>(m_SpecificFP(10.0), m_Value(X
)))))
6287 case Intrinsic::experimental_vector_reverse
:
6288 // experimental.vector.reverse(experimental.vector.reverse(x)) -> x
6289 if (match(Op0
, m_VecReverse(m_Value(X
))))
6291 // experimental.vector.reverse(splat(X)) -> splat(X)
6292 if (isSplatValue(Op0
))
6295 case Intrinsic::frexp
: {
6296 // Frexp is idempotent with the added complication of the struct return.
6297 if (match(Op0
, m_ExtractValue
<0>(m_Value(X
)))) {
6298 if (match(X
, m_Intrinsic
<Intrinsic::frexp
>(m_Value())))
6311 /// Given a min/max intrinsic, see if it can be removed based on having an
6312 /// operand that is another min/max intrinsic with shared operand(s). The caller
6313 /// is expected to swap the operand arguments to handle commutation.
6314 static Value
*foldMinMaxSharedOp(Intrinsic::ID IID
, Value
*Op0
, Value
*Op1
) {
6316 if (!match(Op0
, m_MaxOrMin(m_Value(X
), m_Value(Y
))))
6319 auto *MM0
= dyn_cast
<IntrinsicInst
>(Op0
);
6322 Intrinsic::ID IID0
= MM0
->getIntrinsicID();
6324 if (Op1
== X
|| Op1
== Y
||
6325 match(Op1
, m_c_MaxOrMin(m_Specific(X
), m_Specific(Y
)))) {
6326 // max (max X, Y), X --> max X, Y
6329 // max (min X, Y), X --> X
6330 if (IID0
== getInverseMinMaxIntrinsic(IID
))
6336 /// Given a min/max intrinsic, see if it can be removed based on having an
6337 /// operand that is another min/max intrinsic with shared operand(s). The caller
6338 /// is expected to swap the operand arguments to handle commutation.
6339 static Value
*foldMinimumMaximumSharedOp(Intrinsic::ID IID
, Value
*Op0
,
6341 assert((IID
== Intrinsic::maxnum
|| IID
== Intrinsic::minnum
||
6342 IID
== Intrinsic::maximum
|| IID
== Intrinsic::minimum
) &&
6343 "Unsupported intrinsic");
6345 auto *M0
= dyn_cast
<IntrinsicInst
>(Op0
);
6346 // If Op0 is not the same intrinsic as IID, do not process.
6347 // This is a difference with integer min/max handling. We do not process the
6348 // case like max(min(X,Y),min(X,Y)) => min(X,Y). But it can be handled by GVN.
6349 if (!M0
|| M0
->getIntrinsicID() != IID
)
6351 Value
*X0
= M0
->getOperand(0);
6352 Value
*Y0
= M0
->getOperand(1);
6353 // Simple case, m(m(X,Y), X) => m(X, Y)
6354 // m(m(X,Y), Y) => m(X, Y)
6355 // For minimum/maximum, X is NaN => m(NaN, Y) == NaN and m(NaN, NaN) == NaN.
6356 // For minimum/maximum, Y is NaN => m(X, NaN) == NaN and m(NaN, NaN) == NaN.
6357 // For minnum/maxnum, X is NaN => m(NaN, Y) == Y and m(Y, Y) == Y.
6358 // For minnum/maxnum, Y is NaN => m(X, NaN) == X and m(X, NaN) == X.
6359 if (X0
== Op1
|| Y0
== Op1
)
6362 auto *M1
= dyn_cast
<IntrinsicInst
>(Op1
);
6365 Value
*X1
= M1
->getOperand(0);
6366 Value
*Y1
= M1
->getOperand(1);
6367 Intrinsic::ID IID1
= M1
->getIntrinsicID();
6368 // we have a case m(m(X,Y),m'(X,Y)) taking into account m' is commutative.
6369 // if m' is m or inversion of m => m(m(X,Y),m'(X,Y)) == m(X,Y).
6370 // For minimum/maximum, X is NaN => m(NaN,Y) == m'(NaN, Y) == NaN.
6371 // For minimum/maximum, Y is NaN => m(X,NaN) == m'(X, NaN) == NaN.
6372 // For minnum/maxnum, X is NaN => m(NaN,Y) == m'(NaN, Y) == Y.
6373 // For minnum/maxnum, Y is NaN => m(X,NaN) == m'(X, NaN) == X.
6374 if ((X0
== X1
&& Y0
== Y1
) || (X0
== Y1
&& Y0
== X1
))
6375 if (IID1
== IID
|| getInverseMinMaxIntrinsic(IID1
) == IID
)
6381 static Value
*simplifyBinaryIntrinsic(Function
*F
, Value
*Op0
, Value
*Op1
,
6382 const SimplifyQuery
&Q
,
6383 const CallBase
*Call
) {
6384 Intrinsic::ID IID
= F
->getIntrinsicID();
6385 Type
*ReturnType
= F
->getReturnType();
6386 unsigned BitWidth
= ReturnType
->getScalarSizeInBits();
6388 case Intrinsic::abs
:
6389 // abs(abs(x)) -> abs(x). We don't need to worry about the nsw arg here.
6390 // It is always ok to pick the earlier abs. We'll just lose nsw if its only
6391 // on the outer abs.
6392 if (match(Op0
, m_Intrinsic
<Intrinsic::abs
>(m_Value(), m_Value())))
6396 case Intrinsic::cttz
: {
6398 if (match(Op0
, m_Shl(m_One(), m_Value(X
))))
6402 case Intrinsic::ctlz
: {
6404 if (match(Op0
, m_LShr(m_Negative(), m_Value(X
))))
6406 if (match(Op0
, m_AShr(m_Negative(), m_Value())))
6407 return Constant::getNullValue(ReturnType
);
6410 case Intrinsic::ptrmask
: {
6411 if (isa
<PoisonValue
>(Op0
) || isa
<PoisonValue
>(Op1
))
6412 return PoisonValue::get(Op0
->getType());
6414 // NOTE: We can't apply this simplifications based on the value of Op1
6415 // because we need to preserve provenance.
6416 if (Q
.isUndefValue(Op0
) || match(Op0
, m_Zero()))
6417 return Constant::getNullValue(Op0
->getType());
6419 assert(Op1
->getType()->getScalarSizeInBits() ==
6420 Q
.DL
.getIndexTypeSizeInBits(Op0
->getType()) &&
6421 "Invalid mask width");
6422 // If index-width (mask size) is less than pointer-size then mask is
6424 if (match(Op1
, m_PtrToInt(m_Specific(Op0
))))
6427 // NOTE: We may have attributes associated with the return value of the
6428 // llvm.ptrmask intrinsic that will be lost when we just return the
6429 // operand. We should try to preserve them.
6430 if (match(Op1
, m_AllOnes()) || Q
.isUndefValue(Op1
))
6434 if (match(Op1
, m_ImmConstant(C
))) {
6435 KnownBits PtrKnown
= computeKnownBits(Op0
, /*Depth=*/0, Q
);
6436 // See if we only masking off bits we know are already zero due to
6438 APInt IrrelevantPtrBits
=
6439 PtrKnown
.Zero
.zextOrTrunc(C
->getType()->getScalarSizeInBits());
6440 C
= ConstantFoldBinaryOpOperands(
6441 Instruction::Or
, C
, ConstantInt::get(C
->getType(), IrrelevantPtrBits
),
6443 if (C
!= nullptr && C
->isAllOnesValue())
6448 case Intrinsic::smax
:
6449 case Intrinsic::smin
:
6450 case Intrinsic::umax
:
6451 case Intrinsic::umin
: {
6452 // If the arguments are the same, this is a no-op.
6456 // Canonicalize immediate constant operand as Op1.
6457 if (match(Op0
, m_ImmConstant()))
6458 std::swap(Op0
, Op1
);
6460 // Assume undef is the limit value.
6461 if (Q
.isUndefValue(Op1
))
6462 return ConstantInt::get(
6463 ReturnType
, MinMaxIntrinsic::getSaturationPoint(IID
, BitWidth
));
6466 if (match(Op1
, m_APIntAllowUndef(C
))) {
6467 // Clamp to limit value. For example:
6468 // umax(i8 %x, i8 255) --> 255
6469 if (*C
== MinMaxIntrinsic::getSaturationPoint(IID
, BitWidth
))
6470 return ConstantInt::get(ReturnType
, *C
);
6472 // If the constant op is the opposite of the limit value, the other must
6473 // be larger/smaller or equal. For example:
6474 // umin(i8 %x, i8 255) --> %x
6475 if (*C
== MinMaxIntrinsic::getSaturationPoint(
6476 getInverseMinMaxIntrinsic(IID
), BitWidth
))
6479 // Remove nested call if constant operands allow it. Example:
6480 // max (max X, 7), 5 -> max X, 7
6481 auto *MinMax0
= dyn_cast
<IntrinsicInst
>(Op0
);
6482 if (MinMax0
&& MinMax0
->getIntrinsicID() == IID
) {
6483 // TODO: loosen undef/splat restrictions for vector constants.
6484 Value
*M00
= MinMax0
->getOperand(0), *M01
= MinMax0
->getOperand(1);
6485 const APInt
*InnerC
;
6486 if ((match(M00
, m_APInt(InnerC
)) || match(M01
, m_APInt(InnerC
))) &&
6487 ICmpInst::compare(*InnerC
, *C
,
6488 ICmpInst::getNonStrictPredicate(
6489 MinMaxIntrinsic::getPredicate(IID
))))
6494 if (Value
*V
= foldMinMaxSharedOp(IID
, Op0
, Op1
))
6496 if (Value
*V
= foldMinMaxSharedOp(IID
, Op1
, Op0
))
6499 ICmpInst::Predicate Pred
=
6500 ICmpInst::getNonStrictPredicate(MinMaxIntrinsic::getPredicate(IID
));
6501 if (isICmpTrue(Pred
, Op0
, Op1
, Q
.getWithoutUndef(), RecursionLimit
))
6503 if (isICmpTrue(Pred
, Op1
, Op0
, Q
.getWithoutUndef(), RecursionLimit
))
6508 case Intrinsic::usub_with_overflow
:
6509 case Intrinsic::ssub_with_overflow
:
6510 // X - X -> { 0, false }
6511 // X - undef -> { 0, false }
6512 // undef - X -> { 0, false }
6513 if (Op0
== Op1
|| Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6514 return Constant::getNullValue(ReturnType
);
6516 case Intrinsic::uadd_with_overflow
:
6517 case Intrinsic::sadd_with_overflow
:
6518 // X + undef -> { -1, false }
6519 // undef + x -> { -1, false }
6520 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
)) {
6521 return ConstantStruct::get(
6522 cast
<StructType
>(ReturnType
),
6523 {Constant::getAllOnesValue(ReturnType
->getStructElementType(0)),
6524 Constant::getNullValue(ReturnType
->getStructElementType(1))});
6527 case Intrinsic::umul_with_overflow
:
6528 case Intrinsic::smul_with_overflow
:
6529 // 0 * X -> { 0, false }
6530 // X * 0 -> { 0, false }
6531 if (match(Op0
, m_Zero()) || match(Op1
, m_Zero()))
6532 return Constant::getNullValue(ReturnType
);
6533 // undef * X -> { 0, false }
6534 // X * undef -> { 0, false }
6535 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6536 return Constant::getNullValue(ReturnType
);
6538 case Intrinsic::uadd_sat
:
6539 // sat(MAX + X) -> MAX
6540 // sat(X + MAX) -> MAX
6541 if (match(Op0
, m_AllOnes()) || match(Op1
, m_AllOnes()))
6542 return Constant::getAllOnesValue(ReturnType
);
6544 case Intrinsic::sadd_sat
:
6545 // sat(X + undef) -> -1
6546 // sat(undef + X) -> -1
6547 // For unsigned: Assume undef is MAX, thus we saturate to MAX (-1).
6548 // For signed: Assume undef is ~X, in which case X + ~X = -1.
6549 if (Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6550 return Constant::getAllOnesValue(ReturnType
);
6553 if (match(Op1
, m_Zero()))
6556 if (match(Op0
, m_Zero()))
6559 case Intrinsic::usub_sat
:
6560 // sat(0 - X) -> 0, sat(X - MAX) -> 0
6561 if (match(Op0
, m_Zero()) || match(Op1
, m_AllOnes()))
6562 return Constant::getNullValue(ReturnType
);
6564 case Intrinsic::ssub_sat
:
6565 // X - X -> 0, X - undef -> 0, undef - X -> 0
6566 if (Op0
== Op1
|| Q
.isUndefValue(Op0
) || Q
.isUndefValue(Op1
))
6567 return Constant::getNullValue(ReturnType
);
6569 if (match(Op1
, m_Zero()))
6572 case Intrinsic::load_relative
:
6573 if (auto *C0
= dyn_cast
<Constant
>(Op0
))
6574 if (auto *C1
= dyn_cast
<Constant
>(Op1
))
6575 return simplifyRelativeLoad(C0
, C1
, Q
.DL
);
6577 case Intrinsic::powi
:
6578 if (auto *Power
= dyn_cast
<ConstantInt
>(Op1
)) {
6579 // powi(x, 0) -> 1.0
6580 if (Power
->isZero())
6581 return ConstantFP::get(Op0
->getType(), 1.0);
6587 case Intrinsic::ldexp
:
6588 return simplifyLdexp(Op0
, Op1
, Q
, false);
6589 case Intrinsic::copysign
:
6590 // copysign X, X --> X
6593 // copysign -X, X --> X
6594 // copysign X, -X --> -X
6595 if (match(Op0
, m_FNeg(m_Specific(Op1
))) ||
6596 match(Op1
, m_FNeg(m_Specific(Op0
))))
6599 case Intrinsic::is_fpclass
: {
6600 if (isa
<PoisonValue
>(Op0
))
6601 return PoisonValue::get(ReturnType
);
6603 uint64_t Mask
= cast
<ConstantInt
>(Op1
)->getZExtValue();
6604 // If all tests are made, it doesn't matter what the value is.
6605 if ((Mask
& fcAllFlags
) == fcAllFlags
)
6606 return ConstantInt::get(ReturnType
, true);
6607 if ((Mask
& fcAllFlags
) == 0)
6608 return ConstantInt::get(ReturnType
, false);
6609 if (Q
.isUndefValue(Op0
))
6610 return UndefValue::get(ReturnType
);
6613 case Intrinsic::maxnum
:
6614 case Intrinsic::minnum
:
6615 case Intrinsic::maximum
:
6616 case Intrinsic::minimum
: {
6617 // If the arguments are the same, this is a no-op.
6621 // Canonicalize constant operand as Op1.
6622 if (isa
<Constant
>(Op0
))
6623 std::swap(Op0
, Op1
);
6625 // If an argument is undef, return the other argument.
6626 if (Q
.isUndefValue(Op1
))
6629 bool PropagateNaN
= IID
== Intrinsic::minimum
|| IID
== Intrinsic::maximum
;
6630 bool IsMin
= IID
== Intrinsic::minimum
|| IID
== Intrinsic::minnum
;
6632 // minnum(X, nan) -> X
6633 // maxnum(X, nan) -> X
6634 // minimum(X, nan) -> nan
6635 // maximum(X, nan) -> nan
6636 if (match(Op1
, m_NaN()))
6637 return PropagateNaN
? propagateNaN(cast
<Constant
>(Op1
)) : Op0
;
6639 // In the following folds, inf can be replaced with the largest finite
6640 // float, if the ninf flag is set.
6642 if (match(Op1
, m_APFloat(C
)) &&
6643 (C
->isInfinity() || (Call
->hasNoInfs() && C
->isLargest()))) {
6644 // minnum(X, -inf) -> -inf
6645 // maxnum(X, +inf) -> +inf
6646 // minimum(X, -inf) -> -inf if nnan
6647 // maximum(X, +inf) -> +inf if nnan
6648 if (C
->isNegative() == IsMin
&& (!PropagateNaN
|| Call
->hasNoNaNs()))
6649 return ConstantFP::get(ReturnType
, *C
);
6651 // minnum(X, +inf) -> X if nnan
6652 // maxnum(X, -inf) -> X if nnan
6653 // minimum(X, +inf) -> X
6654 // maximum(X, -inf) -> X
6655 if (C
->isNegative() != IsMin
&& (PropagateNaN
|| Call
->hasNoNaNs()))
6659 // Min/max of the same operation with common operand:
6660 // m(m(X, Y)), X --> m(X, Y) (4 commuted variants)
6661 if (Value
*V
= foldMinimumMaximumSharedOp(IID
, Op0
, Op1
))
6663 if (Value
*V
= foldMinimumMaximumSharedOp(IID
, Op1
, Op0
))
6668 case Intrinsic::vector_extract
: {
6669 Type
*ReturnType
= F
->getReturnType();
6671 // (extract_vector (insert_vector _, X, 0), 0) -> X
6672 unsigned IdxN
= cast
<ConstantInt
>(Op1
)->getZExtValue();
6674 if (match(Op0
, m_Intrinsic
<Intrinsic::vector_insert
>(m_Value(), m_Value(X
),
6676 IdxN
== 0 && X
->getType() == ReturnType
)
6688 static Value
*simplifyIntrinsic(CallBase
*Call
, Value
*Callee
,
6689 ArrayRef
<Value
*> Args
,
6690 const SimplifyQuery
&Q
) {
6691 // Operand bundles should not be in Args.
6692 assert(Call
->arg_size() == Args
.size());
6693 unsigned NumOperands
= Args
.size();
6694 Function
*F
= cast
<Function
>(Callee
);
6695 Intrinsic::ID IID
= F
->getIntrinsicID();
6697 // Most of the intrinsics with no operands have some kind of side effect.
6701 case Intrinsic::vscale
: {
6702 Type
*RetTy
= F
->getReturnType();
6703 ConstantRange CR
= getVScaleRange(Call
->getFunction(), 64);
6704 if (const APInt
*C
= CR
.getSingleElement())
6705 return ConstantInt::get(RetTy
, C
->getZExtValue());
6713 if (NumOperands
== 1)
6714 return simplifyUnaryIntrinsic(F
, Args
[0], Q
, Call
);
6716 if (NumOperands
== 2)
6717 return simplifyBinaryIntrinsic(F
, Args
[0], Args
[1], Q
, Call
);
6719 // Handle intrinsics with 3 or more arguments.
6721 case Intrinsic::masked_load
:
6722 case Intrinsic::masked_gather
: {
6723 Value
*MaskArg
= Args
[2];
6724 Value
*PassthruArg
= Args
[3];
6725 // If the mask is all zeros or undef, the "passthru" argument is the result.
6726 if (maskIsAllZeroOrUndef(MaskArg
))
6730 case Intrinsic::fshl
:
6731 case Intrinsic::fshr
: {
6732 Value
*Op0
= Args
[0], *Op1
= Args
[1], *ShAmtArg
= Args
[2];
6734 // If both operands are undef, the result is undef.
6735 if (Q
.isUndefValue(Op0
) && Q
.isUndefValue(Op1
))
6736 return UndefValue::get(F
->getReturnType());
6738 // If shift amount is undef, assume it is zero.
6739 if (Q
.isUndefValue(ShAmtArg
))
6740 return Args
[IID
== Intrinsic::fshl
? 0 : 1];
6742 const APInt
*ShAmtC
;
6743 if (match(ShAmtArg
, m_APInt(ShAmtC
))) {
6744 // If there's effectively no shift, return the 1st arg or 2nd arg.
6745 APInt BitWidth
= APInt(ShAmtC
->getBitWidth(), ShAmtC
->getBitWidth());
6746 if (ShAmtC
->urem(BitWidth
).isZero())
6747 return Args
[IID
== Intrinsic::fshl
? 0 : 1];
6750 // Rotating zero by anything is zero.
6751 if (match(Op0
, m_Zero()) && match(Op1
, m_Zero()))
6752 return ConstantInt::getNullValue(F
->getReturnType());
6754 // Rotating -1 by anything is -1.
6755 if (match(Op0
, m_AllOnes()) && match(Op1
, m_AllOnes()))
6756 return ConstantInt::getAllOnesValue(F
->getReturnType());
6760 case Intrinsic::experimental_constrained_fma
: {
6761 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6762 if (Value
*V
= simplifyFPOp(Args
, {}, Q
, *FPI
->getExceptionBehavior(),
6763 *FPI
->getRoundingMode()))
6767 case Intrinsic::fma
:
6768 case Intrinsic::fmuladd
: {
6769 if (Value
*V
= simplifyFPOp(Args
, {}, Q
, fp::ebIgnore
,
6770 RoundingMode::NearestTiesToEven
))
6774 case Intrinsic::smul_fix
:
6775 case Intrinsic::smul_fix_sat
: {
6776 Value
*Op0
= Args
[0];
6777 Value
*Op1
= Args
[1];
6778 Value
*Op2
= Args
[2];
6779 Type
*ReturnType
= F
->getReturnType();
6781 // Canonicalize constant operand as Op1 (ConstantFolding handles the case
6782 // when both Op0 and Op1 are constant so we do not care about that special
6784 if (isa
<Constant
>(Op0
))
6785 std::swap(Op0
, Op1
);
6788 if (match(Op1
, m_Zero()))
6789 return Constant::getNullValue(ReturnType
);
6792 if (Q
.isUndefValue(Op1
))
6793 return Constant::getNullValue(ReturnType
);
6795 // X * (1 << Scale) -> X
6797 APInt::getOneBitSet(ReturnType
->getScalarSizeInBits(),
6798 cast
<ConstantInt
>(Op2
)->getZExtValue());
6799 if (ScaledOne
.isNonNegative() && match(Op1
, m_SpecificInt(ScaledOne
)))
6804 case Intrinsic::vector_insert
: {
6805 Value
*Vec
= Args
[0];
6806 Value
*SubVec
= Args
[1];
6807 Value
*Idx
= Args
[2];
6808 Type
*ReturnType
= F
->getReturnType();
6810 // (insert_vector Y, (extract_vector X, 0), 0) -> X
6811 // where: Y is X, or Y is undef
6812 unsigned IdxN
= cast
<ConstantInt
>(Idx
)->getZExtValue();
6815 m_Intrinsic
<Intrinsic::vector_extract
>(m_Value(X
), m_Zero())) &&
6816 (Q
.isUndefValue(Vec
) || Vec
== X
) && IdxN
== 0 &&
6817 X
->getType() == ReturnType
)
6822 case Intrinsic::experimental_constrained_fadd
: {
6823 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6824 return simplifyFAddInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6825 *FPI
->getExceptionBehavior(),
6826 *FPI
->getRoundingMode());
6828 case Intrinsic::experimental_constrained_fsub
: {
6829 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6830 return simplifyFSubInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6831 *FPI
->getExceptionBehavior(),
6832 *FPI
->getRoundingMode());
6834 case Intrinsic::experimental_constrained_fmul
: {
6835 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6836 return simplifyFMulInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6837 *FPI
->getExceptionBehavior(),
6838 *FPI
->getRoundingMode());
6840 case Intrinsic::experimental_constrained_fdiv
: {
6841 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6842 return simplifyFDivInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6843 *FPI
->getExceptionBehavior(),
6844 *FPI
->getRoundingMode());
6846 case Intrinsic::experimental_constrained_frem
: {
6847 auto *FPI
= cast
<ConstrainedFPIntrinsic
>(Call
);
6848 return simplifyFRemInst(Args
[0], Args
[1], FPI
->getFastMathFlags(), Q
,
6849 *FPI
->getExceptionBehavior(),
6850 *FPI
->getRoundingMode());
6852 case Intrinsic::experimental_constrained_ldexp
:
6853 return simplifyLdexp(Args
[0], Args
[1], Q
, true);
6859 static Value
*tryConstantFoldCall(CallBase
*Call
, Value
*Callee
,
6860 ArrayRef
<Value
*> Args
,
6861 const SimplifyQuery
&Q
) {
6862 auto *F
= dyn_cast
<Function
>(Callee
);
6863 if (!F
|| !canConstantFoldCallTo(Call
, F
))
6866 SmallVector
<Constant
*, 4> ConstantArgs
;
6867 ConstantArgs
.reserve(Args
.size());
6868 for (Value
*Arg
: Args
) {
6869 Constant
*C
= dyn_cast
<Constant
>(Arg
);
6871 if (isa
<MetadataAsValue
>(Arg
))
6875 ConstantArgs
.push_back(C
);
6878 return ConstantFoldCall(Call
, F
, ConstantArgs
, Q
.TLI
);
6881 Value
*llvm::simplifyCall(CallBase
*Call
, Value
*Callee
, ArrayRef
<Value
*> Args
,
6882 const SimplifyQuery
&Q
) {
6883 // Args should not contain operand bundle operands.
6884 assert(Call
->arg_size() == Args
.size());
6886 // musttail calls can only be simplified if they are also DCEd.
6887 // As we can't guarantee this here, don't simplify them.
6888 if (Call
->isMustTailCall())
6891 // call undef -> poison
6892 // call null -> poison
6893 if (isa
<UndefValue
>(Callee
) || isa
<ConstantPointerNull
>(Callee
))
6894 return PoisonValue::get(Call
->getType());
6896 if (Value
*V
= tryConstantFoldCall(Call
, Callee
, Args
, Q
))
6899 auto *F
= dyn_cast
<Function
>(Callee
);
6900 if (F
&& F
->isIntrinsic())
6901 if (Value
*Ret
= simplifyIntrinsic(Call
, Callee
, Args
, Q
))
6907 Value
*llvm::simplifyConstrainedFPCall(CallBase
*Call
, const SimplifyQuery
&Q
) {
6908 assert(isa
<ConstrainedFPIntrinsic
>(Call
));
6909 SmallVector
<Value
*, 4> Args(Call
->args());
6910 if (Value
*V
= tryConstantFoldCall(Call
, Call
->getCalledOperand(), Args
, Q
))
6912 if (Value
*Ret
= simplifyIntrinsic(Call
, Call
->getCalledOperand(), Args
, Q
))
6917 /// Given operands for a Freeze, see if we can fold the result.
6918 static Value
*simplifyFreezeInst(Value
*Op0
, const SimplifyQuery
&Q
) {
6919 // Use a utility function defined in ValueTracking.
6920 if (llvm::isGuaranteedNotToBeUndefOrPoison(Op0
, Q
.AC
, Q
.CxtI
, Q
.DT
))
6922 // We have room for improvement.
6926 Value
*llvm::simplifyFreezeInst(Value
*Op0
, const SimplifyQuery
&Q
) {
6927 return ::simplifyFreezeInst(Op0
, Q
);
6930 Value
*llvm::simplifyLoadInst(LoadInst
*LI
, Value
*PtrOp
,
6931 const SimplifyQuery
&Q
) {
6932 if (LI
->isVolatile())
6935 if (auto *PtrOpC
= dyn_cast
<Constant
>(PtrOp
))
6936 return ConstantFoldLoadFromConstPtr(PtrOpC
, LI
->getType(), Q
.DL
);
6938 // We can only fold the load if it is from a constant global with definitive
6939 // initializer. Skip expensive logic if this is not the case.
6940 auto *GV
= dyn_cast
<GlobalVariable
>(getUnderlyingObject(PtrOp
));
6941 if (!GV
|| !GV
->isConstant() || !GV
->hasDefinitiveInitializer())
6944 // If GlobalVariable's initializer is uniform, then return the constant
6945 // regardless of its offset.
6947 ConstantFoldLoadFromUniformValue(GV
->getInitializer(), LI
->getType()))
6950 // Try to convert operand into a constant by stripping offsets while looking
6951 // through invariant.group intrinsics.
6952 APInt
Offset(Q
.DL
.getIndexTypeSizeInBits(PtrOp
->getType()), 0);
6953 PtrOp
= PtrOp
->stripAndAccumulateConstantOffsets(
6954 Q
.DL
, Offset
, /* AllowNonInbounts */ true,
6955 /* AllowInvariantGroup */ true);
6957 // Index size may have changed due to address space casts.
6958 Offset
= Offset
.sextOrTrunc(Q
.DL
.getIndexTypeSizeInBits(PtrOp
->getType()));
6959 return ConstantFoldLoadFromConstPtr(GV
, LI
->getType(), Offset
, Q
.DL
);
6965 /// See if we can compute a simplified version of this instruction.
6966 /// If not, this returns null.
6968 static Value
*simplifyInstructionWithOperands(Instruction
*I
,
6969 ArrayRef
<Value
*> NewOps
,
6970 const SimplifyQuery
&SQ
,
6971 unsigned MaxRecurse
) {
6972 assert(I
->getFunction() && "instruction should be inserted in a function");
6973 assert((!SQ
.CxtI
|| SQ
.CxtI
->getFunction() == I
->getFunction()) &&
6974 "context instruction should be in the same function");
6976 const SimplifyQuery Q
= SQ
.CxtI
? SQ
: SQ
.getWithInstruction(I
);
6978 switch (I
->getOpcode()) {
6980 if (llvm::all_of(NewOps
, [](Value
*V
) { return isa
<Constant
>(V
); })) {
6981 SmallVector
<Constant
*, 8> NewConstOps(NewOps
.size());
6982 transform(NewOps
, NewConstOps
.begin(),
6983 [](Value
*V
) { return cast
<Constant
>(V
); });
6984 return ConstantFoldInstOperands(I
, NewConstOps
, Q
.DL
, Q
.TLI
);
6987 case Instruction::FNeg
:
6988 return simplifyFNegInst(NewOps
[0], I
->getFastMathFlags(), Q
, MaxRecurse
);
6989 case Instruction::FAdd
:
6990 return simplifyFAddInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
6992 case Instruction::Add
:
6993 return simplifyAddInst(
6994 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
6995 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
6996 case Instruction::FSub
:
6997 return simplifyFSubInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
6999 case Instruction::Sub
:
7000 return simplifySubInst(
7001 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
7002 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
7003 case Instruction::FMul
:
7004 return simplifyFMulInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7006 case Instruction::Mul
:
7007 return simplifyMulInst(
7008 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
7009 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
7010 case Instruction::SDiv
:
7011 return simplifySDivInst(NewOps
[0], NewOps
[1],
7012 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7014 case Instruction::UDiv
:
7015 return simplifyUDivInst(NewOps
[0], NewOps
[1],
7016 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7018 case Instruction::FDiv
:
7019 return simplifyFDivInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7021 case Instruction::SRem
:
7022 return simplifySRemInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7023 case Instruction::URem
:
7024 return simplifyURemInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7025 case Instruction::FRem
:
7026 return simplifyFRemInst(NewOps
[0], NewOps
[1], I
->getFastMathFlags(), Q
,
7028 case Instruction::Shl
:
7029 return simplifyShlInst(
7030 NewOps
[0], NewOps
[1], Q
.IIQ
.hasNoSignedWrap(cast
<BinaryOperator
>(I
)),
7031 Q
.IIQ
.hasNoUnsignedWrap(cast
<BinaryOperator
>(I
)), Q
, MaxRecurse
);
7032 case Instruction::LShr
:
7033 return simplifyLShrInst(NewOps
[0], NewOps
[1],
7034 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7036 case Instruction::AShr
:
7037 return simplifyAShrInst(NewOps
[0], NewOps
[1],
7038 Q
.IIQ
.isExact(cast
<BinaryOperator
>(I
)), Q
,
7040 case Instruction::And
:
7041 return simplifyAndInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7042 case Instruction::Or
:
7043 return simplifyOrInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7044 case Instruction::Xor
:
7045 return simplifyXorInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7046 case Instruction::ICmp
:
7047 return simplifyICmpInst(cast
<ICmpInst
>(I
)->getPredicate(), NewOps
[0],
7048 NewOps
[1], Q
, MaxRecurse
);
7049 case Instruction::FCmp
:
7050 return simplifyFCmpInst(cast
<FCmpInst
>(I
)->getPredicate(), NewOps
[0],
7051 NewOps
[1], I
->getFastMathFlags(), Q
, MaxRecurse
);
7052 case Instruction::Select
:
7053 return simplifySelectInst(NewOps
[0], NewOps
[1], NewOps
[2], Q
, MaxRecurse
);
7055 case Instruction::GetElementPtr
: {
7056 auto *GEPI
= cast
<GetElementPtrInst
>(I
);
7057 return simplifyGEPInst(GEPI
->getSourceElementType(), NewOps
[0],
7058 ArrayRef(NewOps
).slice(1), GEPI
->isInBounds(), Q
,
7061 case Instruction::InsertValue
: {
7062 InsertValueInst
*IV
= cast
<InsertValueInst
>(I
);
7063 return simplifyInsertValueInst(NewOps
[0], NewOps
[1], IV
->getIndices(), Q
,
7066 case Instruction::InsertElement
:
7067 return simplifyInsertElementInst(NewOps
[0], NewOps
[1], NewOps
[2], Q
);
7068 case Instruction::ExtractValue
: {
7069 auto *EVI
= cast
<ExtractValueInst
>(I
);
7070 return simplifyExtractValueInst(NewOps
[0], EVI
->getIndices(), Q
,
7073 case Instruction::ExtractElement
:
7074 return simplifyExtractElementInst(NewOps
[0], NewOps
[1], Q
, MaxRecurse
);
7075 case Instruction::ShuffleVector
: {
7076 auto *SVI
= cast
<ShuffleVectorInst
>(I
);
7077 return simplifyShuffleVectorInst(NewOps
[0], NewOps
[1],
7078 SVI
->getShuffleMask(), SVI
->getType(), Q
,
7081 case Instruction::PHI
:
7082 return simplifyPHINode(cast
<PHINode
>(I
), NewOps
, Q
);
7083 case Instruction::Call
:
7084 return simplifyCall(
7085 cast
<CallInst
>(I
), NewOps
.back(),
7086 NewOps
.drop_back(1 + cast
<CallInst
>(I
)->getNumTotalBundleOperands()), Q
);
7087 case Instruction::Freeze
:
7088 return llvm::simplifyFreezeInst(NewOps
[0], Q
);
7089 #define HANDLE_CAST_INST(num, opc, clas) case Instruction::opc:
7090 #include "llvm/IR/Instruction.def"
7091 #undef HANDLE_CAST_INST
7092 return simplifyCastInst(I
->getOpcode(), NewOps
[0], I
->getType(), Q
,
7094 case Instruction::Alloca
:
7095 // No simplifications for Alloca and it can't be constant folded.
7097 case Instruction::Load
:
7098 return simplifyLoadInst(cast
<LoadInst
>(I
), NewOps
[0], Q
);
7102 Value
*llvm::simplifyInstructionWithOperands(Instruction
*I
,
7103 ArrayRef
<Value
*> NewOps
,
7104 const SimplifyQuery
&SQ
) {
7105 assert(NewOps
.size() == I
->getNumOperands() &&
7106 "Number of operands should match the instruction!");
7107 return ::simplifyInstructionWithOperands(I
, NewOps
, SQ
, RecursionLimit
);
7110 Value
*llvm::simplifyInstruction(Instruction
*I
, const SimplifyQuery
&SQ
) {
7111 SmallVector
<Value
*, 8> Ops(I
->operands());
7112 Value
*Result
= ::simplifyInstructionWithOperands(I
, Ops
, SQ
, RecursionLimit
);
7114 /// If called on unreachable code, the instruction may simplify to itself.
7115 /// Make life easier for users by detecting that case here, and returning a
7116 /// safe value instead.
7117 return Result
== I
? UndefValue::get(I
->getType()) : Result
;
7120 /// Implementation of recursive simplification through an instruction's
7123 /// This is the common implementation of the recursive simplification routines.
7124 /// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
7125 /// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
7126 /// instructions to process and attempt to simplify it using
7127 /// InstructionSimplify. Recursively visited users which could not be
7128 /// simplified themselves are to the optional UnsimplifiedUsers set for
7129 /// further processing by the caller.
7131 /// This routine returns 'true' only when *it* simplifies something. The passed
7132 /// in simplified value does not count toward this.
7133 static bool replaceAndRecursivelySimplifyImpl(
7134 Instruction
*I
, Value
*SimpleV
, const TargetLibraryInfo
*TLI
,
7135 const DominatorTree
*DT
, AssumptionCache
*AC
,
7136 SmallSetVector
<Instruction
*, 8> *UnsimplifiedUsers
= nullptr) {
7137 bool Simplified
= false;
7138 SmallSetVector
<Instruction
*, 8> Worklist
;
7139 const DataLayout
&DL
= I
->getModule()->getDataLayout();
7141 // If we have an explicit value to collapse to, do that round of the
7142 // simplification loop by hand initially.
7144 for (User
*U
: I
->users())
7146 Worklist
.insert(cast
<Instruction
>(U
));
7148 // Replace the instruction with its simplified value.
7149 I
->replaceAllUsesWith(SimpleV
);
7151 if (!I
->isEHPad() && !I
->isTerminator() && !I
->mayHaveSideEffects())
7152 I
->eraseFromParent();
7157 // Note that we must test the size on each iteration, the worklist can grow.
7158 for (unsigned Idx
= 0; Idx
!= Worklist
.size(); ++Idx
) {
7161 // See if this instruction simplifies.
7162 SimpleV
= simplifyInstruction(I
, {DL
, TLI
, DT
, AC
});
7164 if (UnsimplifiedUsers
)
7165 UnsimplifiedUsers
->insert(I
);
7171 // Stash away all the uses of the old instruction so we can check them for
7172 // recursive simplifications after a RAUW. This is cheaper than checking all
7173 // uses of To on the recursive step in most cases.
7174 for (User
*U
: I
->users())
7175 Worklist
.insert(cast
<Instruction
>(U
));
7177 // Replace the instruction with its simplified value.
7178 I
->replaceAllUsesWith(SimpleV
);
7180 if (!I
->isEHPad() && !I
->isTerminator() && !I
->mayHaveSideEffects())
7181 I
->eraseFromParent();
7186 bool llvm::replaceAndRecursivelySimplify(
7187 Instruction
*I
, Value
*SimpleV
, const TargetLibraryInfo
*TLI
,
7188 const DominatorTree
*DT
, AssumptionCache
*AC
,
7189 SmallSetVector
<Instruction
*, 8> *UnsimplifiedUsers
) {
7190 assert(I
!= SimpleV
&& "replaceAndRecursivelySimplify(X,X) is not valid!");
7191 assert(SimpleV
&& "Must provide a simplified value.");
7192 return replaceAndRecursivelySimplifyImpl(I
, SimpleV
, TLI
, DT
, AC
,
7197 const SimplifyQuery
getBestSimplifyQuery(Pass
&P
, Function
&F
) {
7198 auto *DTWP
= P
.getAnalysisIfAvailable
<DominatorTreeWrapperPass
>();
7199 auto *DT
= DTWP
? &DTWP
->getDomTree() : nullptr;
7200 auto *TLIWP
= P
.getAnalysisIfAvailable
<TargetLibraryInfoWrapperPass
>();
7201 auto *TLI
= TLIWP
? &TLIWP
->getTLI(F
) : nullptr;
7202 auto *ACWP
= P
.getAnalysisIfAvailable
<AssumptionCacheTracker
>();
7203 auto *AC
= ACWP
? &ACWP
->getAssumptionCache(F
) : nullptr;
7204 return {F
.getParent()->getDataLayout(), TLI
, DT
, AC
};
7207 const SimplifyQuery
getBestSimplifyQuery(LoopStandardAnalysisResults
&AR
,
7208 const DataLayout
&DL
) {
7209 return {DL
, &AR
.TLI
, &AR
.DT
, &AR
.AC
};
7212 template <class T
, class... TArgs
>
7213 const SimplifyQuery
getBestSimplifyQuery(AnalysisManager
<T
, TArgs
...> &AM
,
7215 auto *DT
= AM
.template getCachedResult
<DominatorTreeAnalysis
>(F
);
7216 auto *TLI
= AM
.template getCachedResult
<TargetLibraryAnalysis
>(F
);
7217 auto *AC
= AM
.template getCachedResult
<AssumptionAnalysis
>(F
);
7218 return {F
.getParent()->getDataLayout(), TLI
, DT
, AC
};
7220 template const SimplifyQuery
getBestSimplifyQuery(AnalysisManager
<Function
> &,
7224 void InstSimplifyFolder::anchor() {}