1 //===- InstructionSimplify.cpp - Fold instruction operands ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements routines for folding instructions into simpler forms
11 // that do not require creating new instructions. This does constant folding
12 // ("add i32 1, 1" -> "2") but can also handle non-constant operands, either
13 // returning a constant ("and i32 %x, 0" -> "0") or an already existing value
14 // ("and i32 %x, %x" -> "%x"). All operands are assumed to have already been
15 // simplified: This is usually true and assuming it simplifies the logic (if
16 // they have not been simplified then results are correct but maybe suboptimal).
18 //===----------------------------------------------------------------------===//
20 #include "llvm/Analysis/InstructionSimplify.h"
21 #include "llvm/ADT/SetVector.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/Analysis/AliasAnalysis.h"
24 #include "llvm/Analysis/ConstantFolding.h"
25 #include "llvm/Analysis/MemoryBuiltins.h"
26 #include "llvm/Analysis/ValueTracking.h"
27 #include "llvm/Analysis/VectorUtils.h"
28 #include "llvm/IR/ConstantRange.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/Dominators.h"
31 #include "llvm/IR/GetElementPtrTypeIterator.h"
32 #include "llvm/IR/GlobalAlias.h"
33 #include "llvm/IR/Operator.h"
34 #include "llvm/IR/PatternMatch.h"
35 #include "llvm/IR/ValueHandle.h"
38 using namespace llvm::PatternMatch;
40 #define DEBUG_TYPE "instsimplify"
42 enum { RecursionLimit = 3 };
44 STATISTIC(NumExpand, "Number of expansions");
45 STATISTIC(NumReassoc, "Number of reassociations");
50 const TargetLibraryInfo *TLI;
51 const DominatorTree *DT;
53 const Instruction *CxtI;
55 Query(const DataLayout &DL, const TargetLibraryInfo *tli,
56 const DominatorTree *dt, AssumptionCache *ac = nullptr,
57 const Instruction *cxti = nullptr)
58 : DL(DL), TLI(tli), DT(dt), AC(ac), CxtI(cxti) {}
60 } // end anonymous namespace
62 static Value *SimplifyAndInst(Value *, Value *, const Query &, unsigned);
63 static Value *SimplifyBinOp(unsigned, Value *, Value *, const Query &,
65 static Value *SimplifyFPBinOp(unsigned, Value *, Value *, const FastMathFlags &,
66 const Query &, unsigned);
67 static Value *SimplifyCmpInst(unsigned, Value *, Value *, const Query &,
69 static Value *SimplifyOrInst(Value *, Value *, const Query &, unsigned);
70 static Value *SimplifyXorInst(Value *, Value *, const Query &, unsigned);
71 static Value *SimplifyTruncInst(Value *, Type *, const Query &, unsigned);
73 /// For a boolean type, or a vector of boolean type, return false, or
74 /// a vector with every element false, as appropriate for the type.
75 static Constant *getFalse(Type *Ty) {
76 assert(Ty->getScalarType()->isIntegerTy(1) &&
77 "Expected i1 type or a vector of i1!");
78 return Constant::getNullValue(Ty);
81 /// For a boolean type, or a vector of boolean type, return true, or
82 /// a vector with every element true, as appropriate for the type.
83 static Constant *getTrue(Type *Ty) {
84 assert(Ty->getScalarType()->isIntegerTy(1) &&
85 "Expected i1 type or a vector of i1!");
86 return Constant::getAllOnesValue(Ty);
89 /// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"?
90 static bool isSameCompare(Value *V, CmpInst::Predicate Pred, Value *LHS,
92 CmpInst *Cmp = dyn_cast<CmpInst>(V);
95 CmpInst::Predicate CPred = Cmp->getPredicate();
96 Value *CLHS = Cmp->getOperand(0), *CRHS = Cmp->getOperand(1);
97 if (CPred == Pred && CLHS == LHS && CRHS == RHS)
99 return CPred == CmpInst::getSwappedPredicate(Pred) && CLHS == RHS &&
103 /// Does the given value dominate the specified phi node?
104 static bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) {
105 Instruction *I = dyn_cast<Instruction>(V);
107 // Arguments and constants dominate all instructions.
110 // If we are processing instructions (and/or basic blocks) that have not been
111 // fully added to a function, the parent nodes may still be null. Simply
112 // return the conservative answer in these cases.
113 if (!I->getParent() || !P->getParent() || !I->getParent()->getParent())
116 // If we have a DominatorTree then do a precise test.
118 if (!DT->isReachableFromEntry(P->getParent()))
120 if (!DT->isReachableFromEntry(I->getParent()))
122 return DT->dominates(I, P);
125 // Otherwise, if the instruction is in the entry block and is not an invoke,
126 // then it obviously dominates all phi nodes.
127 if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() &&
134 /// Simplify "A op (B op' C)" by distributing op over op', turning it into
135 /// "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is
136 /// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS.
137 /// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)".
138 /// Returns the simplified value, or null if no simplification was performed.
139 static Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS,
140 unsigned OpcToExpand, const Query &Q,
141 unsigned MaxRecurse) {
142 Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand;
143 // Recursion is always used, so bail out at once if we already hit the limit.
147 // Check whether the expression has the form "(A op' B) op C".
148 if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS))
149 if (Op0->getOpcode() == OpcodeToExpand) {
150 // It does! Try turning it into "(A op C) op' (B op C)".
151 Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS;
152 // Do "A op C" and "B op C" both simplify?
153 if (Value *L = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse))
154 if (Value *R = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
155 // They do! Return "L op' R" if it simplifies or is already available.
156 // If "L op' R" equals "A op' B" then "L op' R" is just the LHS.
157 if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand)
158 && L == B && R == A)) {
162 // Otherwise return "L op' R" if it simplifies.
163 if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
170 // Check whether the expression has the form "A op (B op' C)".
171 if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS))
172 if (Op1->getOpcode() == OpcodeToExpand) {
173 // It does! Try turning it into "(A op B) op' (A op C)".
174 Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1);
175 // Do "A op B" and "A op C" both simplify?
176 if (Value *L = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse))
177 if (Value *R = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse)) {
178 // They do! Return "L op' R" if it simplifies or is already available.
179 // If "L op' R" equals "B op' C" then "L op' R" is just the RHS.
180 if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand)
181 && L == C && R == B)) {
185 // Otherwise return "L op' R" if it simplifies.
186 if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
196 /// Generic simplifications for associative binary operations.
197 /// Returns the simpler value, or null if none was found.
198 static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS,
199 const Query &Q, unsigned MaxRecurse) {
200 Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc;
201 assert(Instruction::isAssociative(Opcode) && "Not an associative operation!");
203 // Recursion is always used, so bail out at once if we already hit the limit.
207 BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
208 BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
210 // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely.
211 if (Op0 && Op0->getOpcode() == Opcode) {
212 Value *A = Op0->getOperand(0);
213 Value *B = Op0->getOperand(1);
216 // Does "B op C" simplify?
217 if (Value *V = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
218 // It does! Return "A op V" if it simplifies or is already available.
219 // If V equals B then "A op V" is just the LHS.
220 if (V == B) return LHS;
221 // Otherwise return "A op V" if it simplifies.
222 if (Value *W = SimplifyBinOp(Opcode, A, V, Q, MaxRecurse)) {
229 // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely.
230 if (Op1 && Op1->getOpcode() == Opcode) {
232 Value *B = Op1->getOperand(0);
233 Value *C = Op1->getOperand(1);
235 // Does "A op B" simplify?
236 if (Value *V = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse)) {
237 // It does! Return "V op C" if it simplifies or is already available.
238 // If V equals B then "V op C" is just the RHS.
239 if (V == B) return RHS;
240 // Otherwise return "V op C" if it simplifies.
241 if (Value *W = SimplifyBinOp(Opcode, V, C, Q, MaxRecurse)) {
248 // The remaining transforms require commutativity as well as associativity.
249 if (!Instruction::isCommutative(Opcode))
252 // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely.
253 if (Op0 && Op0->getOpcode() == Opcode) {
254 Value *A = Op0->getOperand(0);
255 Value *B = Op0->getOperand(1);
258 // Does "C op A" simplify?
259 if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
260 // It does! Return "V op B" if it simplifies or is already available.
261 // If V equals A then "V op B" is just the LHS.
262 if (V == A) return LHS;
263 // Otherwise return "V op B" if it simplifies.
264 if (Value *W = SimplifyBinOp(Opcode, V, B, Q, MaxRecurse)) {
271 // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely.
272 if (Op1 && Op1->getOpcode() == Opcode) {
274 Value *B = Op1->getOperand(0);
275 Value *C = Op1->getOperand(1);
277 // Does "C op A" simplify?
278 if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
279 // It does! Return "B op V" if it simplifies or is already available.
280 // If V equals C then "B op V" is just the RHS.
281 if (V == C) return RHS;
282 // Otherwise return "B op V" if it simplifies.
283 if (Value *W = SimplifyBinOp(Opcode, B, V, Q, MaxRecurse)) {
293 /// In the case of a binary operation with a select instruction as an operand,
294 /// try to simplify the binop by seeing whether evaluating it on both branches
295 /// of the select results in the same value. Returns the common value if so,
296 /// otherwise returns null.
297 static Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS,
298 const Query &Q, unsigned MaxRecurse) {
299 // Recursion is always used, so bail out at once if we already hit the limit.
304 if (isa<SelectInst>(LHS)) {
305 SI = cast<SelectInst>(LHS);
307 assert(isa<SelectInst>(RHS) && "No select instruction operand!");
308 SI = cast<SelectInst>(RHS);
311 // Evaluate the BinOp on the true and false branches of the select.
315 TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, Q, MaxRecurse);
316 FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, Q, MaxRecurse);
318 TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), Q, MaxRecurse);
319 FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), Q, MaxRecurse);
322 // If they simplified to the same value, then return the common value.
323 // If they both failed to simplify then return null.
327 // If one branch simplified to undef, return the other one.
328 if (TV && isa<UndefValue>(TV))
330 if (FV && isa<UndefValue>(FV))
333 // If applying the operation did not change the true and false select values,
334 // then the result of the binop is the select itself.
335 if (TV == SI->getTrueValue() && FV == SI->getFalseValue())
338 // If one branch simplified and the other did not, and the simplified
339 // value is equal to the unsimplified one, return the simplified value.
340 // For example, select (cond, X, X & Z) & Z -> X & Z.
341 if ((FV && !TV) || (TV && !FV)) {
342 // Check that the simplified value has the form "X op Y" where "op" is the
343 // same as the original operation.
344 Instruction *Simplified = dyn_cast<Instruction>(FV ? FV : TV);
345 if (Simplified && Simplified->getOpcode() == Opcode) {
346 // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS".
347 // We already know that "op" is the same as for the simplified value. See
348 // if the operands match too. If so, return the simplified value.
349 Value *UnsimplifiedBranch = FV ? SI->getTrueValue() : SI->getFalseValue();
350 Value *UnsimplifiedLHS = SI == LHS ? UnsimplifiedBranch : LHS;
351 Value *UnsimplifiedRHS = SI == LHS ? RHS : UnsimplifiedBranch;
352 if (Simplified->getOperand(0) == UnsimplifiedLHS &&
353 Simplified->getOperand(1) == UnsimplifiedRHS)
355 if (Simplified->isCommutative() &&
356 Simplified->getOperand(1) == UnsimplifiedLHS &&
357 Simplified->getOperand(0) == UnsimplifiedRHS)
365 /// In the case of a comparison with a select instruction, try to simplify the
366 /// comparison by seeing whether both branches of the select result in the same
367 /// value. Returns the common value if so, otherwise returns null.
368 static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS,
369 Value *RHS, const Query &Q,
370 unsigned MaxRecurse) {
371 // Recursion is always used, so bail out at once if we already hit the limit.
375 // Make sure the select is on the LHS.
376 if (!isa<SelectInst>(LHS)) {
378 Pred = CmpInst::getSwappedPredicate(Pred);
380 assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!");
381 SelectInst *SI = cast<SelectInst>(LHS);
382 Value *Cond = SI->getCondition();
383 Value *TV = SI->getTrueValue();
384 Value *FV = SI->getFalseValue();
386 // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it.
387 // Does "cmp TV, RHS" simplify?
388 Value *TCmp = SimplifyCmpInst(Pred, TV, RHS, Q, MaxRecurse);
390 // It not only simplified, it simplified to the select condition. Replace
392 TCmp = getTrue(Cond->getType());
394 // It didn't simplify. However if "cmp TV, RHS" is equal to the select
395 // condition then we can replace it with 'true'. Otherwise give up.
396 if (!isSameCompare(Cond, Pred, TV, RHS))
398 TCmp = getTrue(Cond->getType());
401 // Does "cmp FV, RHS" simplify?
402 Value *FCmp = SimplifyCmpInst(Pred, FV, RHS, Q, MaxRecurse);
404 // It not only simplified, it simplified to the select condition. Replace
406 FCmp = getFalse(Cond->getType());
408 // It didn't simplify. However if "cmp FV, RHS" is equal to the select
409 // condition then we can replace it with 'false'. Otherwise give up.
410 if (!isSameCompare(Cond, Pred, FV, RHS))
412 FCmp = getFalse(Cond->getType());
415 // If both sides simplified to the same value, then use it as the result of
416 // the original comparison.
420 // The remaining cases only make sense if the select condition has the same
421 // type as the result of the comparison, so bail out if this is not so.
422 if (Cond->getType()->isVectorTy() != RHS->getType()->isVectorTy())
424 // If the false value simplified to false, then the result of the compare
425 // is equal to "Cond && TCmp". This also catches the case when the false
426 // value simplified to false and the true value to true, returning "Cond".
427 if (match(FCmp, m_Zero()))
428 if (Value *V = SimplifyAndInst(Cond, TCmp, Q, MaxRecurse))
430 // If the true value simplified to true, then the result of the compare
431 // is equal to "Cond || FCmp".
432 if (match(TCmp, m_One()))
433 if (Value *V = SimplifyOrInst(Cond, FCmp, Q, MaxRecurse))
435 // Finally, if the false value simplified to true and the true value to
436 // false, then the result of the compare is equal to "!Cond".
437 if (match(FCmp, m_One()) && match(TCmp, m_Zero()))
439 SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()),
446 /// In the case of a binary operation with an operand that is a PHI instruction,
447 /// try to simplify the binop by seeing whether evaluating it on the incoming
448 /// phi values yields the same result for every value. If so returns the common
449 /// value, otherwise returns null.
450 static Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS,
451 const Query &Q, unsigned MaxRecurse) {
452 // Recursion is always used, so bail out at once if we already hit the limit.
457 if (isa<PHINode>(LHS)) {
458 PI = cast<PHINode>(LHS);
459 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
460 if (!ValueDominatesPHI(RHS, PI, Q.DT))
463 assert(isa<PHINode>(RHS) && "No PHI instruction operand!");
464 PI = cast<PHINode>(RHS);
465 // Bail out if LHS and the phi may be mutually interdependent due to a loop.
466 if (!ValueDominatesPHI(LHS, PI, Q.DT))
470 // Evaluate the BinOp on the incoming phi values.
471 Value *CommonValue = nullptr;
472 for (Value *Incoming : PI->incoming_values()) {
473 // If the incoming value is the phi node itself, it can safely be skipped.
474 if (Incoming == PI) continue;
475 Value *V = PI == LHS ?
476 SimplifyBinOp(Opcode, Incoming, RHS, Q, MaxRecurse) :
477 SimplifyBinOp(Opcode, LHS, Incoming, Q, MaxRecurse);
478 // If the operation failed to simplify, or simplified to a different value
479 // to previously, then give up.
480 if (!V || (CommonValue && V != CommonValue))
488 /// In the case of a comparison with a PHI instruction, try to simplify the
489 /// comparison by seeing whether comparing with all of the incoming phi values
490 /// yields the same result every time. If so returns the common result,
491 /// otherwise returns null.
492 static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS,
493 const Query &Q, unsigned MaxRecurse) {
494 // Recursion is always used, so bail out at once if we already hit the limit.
498 // Make sure the phi is on the LHS.
499 if (!isa<PHINode>(LHS)) {
501 Pred = CmpInst::getSwappedPredicate(Pred);
503 assert(isa<PHINode>(LHS) && "Not comparing with a phi instruction!");
504 PHINode *PI = cast<PHINode>(LHS);
506 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
507 if (!ValueDominatesPHI(RHS, PI, Q.DT))
510 // Evaluate the BinOp on the incoming phi values.
511 Value *CommonValue = nullptr;
512 for (Value *Incoming : PI->incoming_values()) {
513 // If the incoming value is the phi node itself, it can safely be skipped.
514 if (Incoming == PI) continue;
515 Value *V = SimplifyCmpInst(Pred, Incoming, RHS, Q, MaxRecurse);
516 // If the operation failed to simplify, or simplified to a different value
517 // to previously, then give up.
518 if (!V || (CommonValue && V != CommonValue))
526 /// Given operands for an Add, see if we can fold the result.
527 /// If not, this returns null.
528 static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
529 const Query &Q, unsigned MaxRecurse) {
530 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
531 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
532 Constant *Ops[] = { CLHS, CRHS };
533 return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), Ops,
537 // Canonicalize the constant to the RHS.
541 // X + undef -> undef
542 if (match(Op1, m_Undef()))
546 if (match(Op1, m_Zero()))
553 if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) ||
554 match(Op0, m_Sub(m_Value(Y), m_Specific(Op1))))
557 // X + ~X -> -1 since ~X = -X-1
558 if (match(Op0, m_Not(m_Specific(Op1))) ||
559 match(Op1, m_Not(m_Specific(Op0))))
560 return Constant::getAllOnesValue(Op0->getType());
563 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
564 if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
567 // Try some generic simplifications for associative operations.
568 if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, Q,
572 // Threading Add over selects and phi nodes is pointless, so don't bother.
573 // Threading over the select in "A + select(cond, B, C)" means evaluating
574 // "A+B" and "A+C" and seeing if they are equal; but they are equal if and
575 // only if B and C are equal. If B and C are equal then (since we assume
576 // that operands have already been simplified) "select(cond, B, C)" should
577 // have been simplified to the common value of B and C already. Analysing
578 // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
579 // for threading over phi nodes.
584 Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
585 const DataLayout &DL, const TargetLibraryInfo *TLI,
586 const DominatorTree *DT, AssumptionCache *AC,
587 const Instruction *CxtI) {
588 return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI),
592 /// \brief Compute the base pointer and cumulative constant offsets for V.
594 /// This strips all constant offsets off of V, leaving it the base pointer, and
595 /// accumulates the total constant offset applied in the returned constant. It
596 /// returns 0 if V is not a pointer, and returns the constant '0' if there are
597 /// no constant offsets applied.
599 /// This is very similar to GetPointerBaseWithConstantOffset except it doesn't
600 /// follow non-inbounds geps. This allows it to remain usable for icmp ult/etc.
602 static Constant *stripAndComputeConstantOffsets(const DataLayout &DL, Value *&V,
603 bool AllowNonInbounds = false) {
604 assert(V->getType()->getScalarType()->isPointerTy());
606 Type *IntPtrTy = DL.getIntPtrType(V->getType())->getScalarType();
607 APInt Offset = APInt::getNullValue(IntPtrTy->getIntegerBitWidth());
609 // Even though we don't look through PHI nodes, we could be called on an
610 // instruction in an unreachable block, which may be on a cycle.
611 SmallPtrSet<Value *, 4> Visited;
614 if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
615 if ((!AllowNonInbounds && !GEP->isInBounds()) ||
616 !GEP->accumulateConstantOffset(DL, Offset))
618 V = GEP->getPointerOperand();
619 } else if (Operator::getOpcode(V) == Instruction::BitCast) {
620 V = cast<Operator>(V)->getOperand(0);
621 } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
622 if (GA->mayBeOverridden())
624 V = GA->getAliasee();
628 assert(V->getType()->getScalarType()->isPointerTy() &&
629 "Unexpected operand type!");
630 } while (Visited.insert(V).second);
632 Constant *OffsetIntPtr = ConstantInt::get(IntPtrTy, Offset);
633 if (V->getType()->isVectorTy())
634 return ConstantVector::getSplat(V->getType()->getVectorNumElements(),
639 /// \brief Compute the constant difference between two pointer values.
640 /// If the difference is not a constant, returns zero.
641 static Constant *computePointerDifference(const DataLayout &DL, Value *LHS,
643 Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS);
644 Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS);
646 // If LHS and RHS are not related via constant offsets to the same base
647 // value, there is nothing we can do here.
651 // Otherwise, the difference of LHS - RHS can be computed as:
653 // = (LHSOffset + Base) - (RHSOffset + Base)
654 // = LHSOffset - RHSOffset
655 return ConstantExpr::getSub(LHSOffset, RHSOffset);
658 /// Given operands for a Sub, see if we can fold the result.
659 /// If not, this returns null.
660 static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
661 const Query &Q, unsigned MaxRecurse) {
662 if (Constant *CLHS = dyn_cast<Constant>(Op0))
663 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
664 Constant *Ops[] = { CLHS, CRHS };
665 return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(),
669 // X - undef -> undef
670 // undef - X -> undef
671 if (match(Op0, m_Undef()) || match(Op1, m_Undef()))
672 return UndefValue::get(Op0->getType());
675 if (match(Op1, m_Zero()))
680 return Constant::getNullValue(Op0->getType());
682 // 0 - X -> 0 if the sub is NUW.
683 if (isNUW && match(Op0, m_Zero()))
686 // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
687 // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
688 Value *X = nullptr, *Y = nullptr, *Z = Op1;
689 if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
690 // See if "V === Y - Z" simplifies.
691 if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1))
692 // It does! Now see if "X + V" simplifies.
693 if (Value *W = SimplifyBinOp(Instruction::Add, X, V, Q, MaxRecurse-1)) {
694 // It does, we successfully reassociated!
698 // See if "V === X - Z" simplifies.
699 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
700 // It does! Now see if "Y + V" simplifies.
701 if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, Q, MaxRecurse-1)) {
702 // It does, we successfully reassociated!
708 // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
709 // For example, X - (X + 1) -> -1
711 if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z)
712 // See if "V === X - Y" simplifies.
713 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
714 // It does! Now see if "V - Z" simplifies.
715 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, Q, MaxRecurse-1)) {
716 // It does, we successfully reassociated!
720 // See if "V === X - Z" simplifies.
721 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
722 // It does! Now see if "V - Y" simplifies.
723 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, Q, MaxRecurse-1)) {
724 // It does, we successfully reassociated!
730 // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
731 // For example, X - (X - Y) -> Y.
733 if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y)
734 // See if "V === Z - X" simplifies.
735 if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, Q, MaxRecurse-1))
736 // It does! Now see if "V + Y" simplifies.
737 if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, Q, MaxRecurse-1)) {
738 // It does, we successfully reassociated!
743 // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
744 if (MaxRecurse && match(Op0, m_Trunc(m_Value(X))) &&
745 match(Op1, m_Trunc(m_Value(Y))))
746 if (X->getType() == Y->getType())
747 // See if "V === X - Y" simplifies.
748 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
749 // It does! Now see if "trunc V" simplifies.
750 if (Value *W = SimplifyTruncInst(V, Op0->getType(), Q, MaxRecurse-1))
751 // It does, return the simplified "trunc V".
754 // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
755 if (match(Op0, m_PtrToInt(m_Value(X))) &&
756 match(Op1, m_PtrToInt(m_Value(Y))))
757 if (Constant *Result = computePointerDifference(Q.DL, X, Y))
758 return ConstantExpr::getIntegerCast(Result, Op0->getType(), true);
761 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
762 if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
765 // Threading Sub over selects and phi nodes is pointless, so don't bother.
766 // Threading over the select in "A - select(cond, B, C)" means evaluating
767 // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
768 // only if B and C are equal. If B and C are equal then (since we assume
769 // that operands have already been simplified) "select(cond, B, C)" should
770 // have been simplified to the common value of B and C already. Analysing
771 // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
772 // for threading over phi nodes.
777 Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
778 const DataLayout &DL, const TargetLibraryInfo *TLI,
779 const DominatorTree *DT, AssumptionCache *AC,
780 const Instruction *CxtI) {
781 return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI),
785 /// Given operands for an FAdd, see if we can fold the result. If not, this
787 static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
788 const Query &Q, unsigned MaxRecurse) {
789 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
790 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
791 Constant *Ops[] = { CLHS, CRHS };
792 return ConstantFoldInstOperands(Instruction::FAdd, CLHS->getType(),
796 // Canonicalize the constant to the RHS.
801 if (match(Op1, m_NegZero()))
804 // fadd X, 0 ==> X, when we know X is not -0
805 if (match(Op1, m_Zero()) &&
806 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
809 // fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
810 // where nnan and ninf have to occur at least once somewhere in this
812 Value *SubOp = nullptr;
813 if (match(Op1, m_FSub(m_AnyZero(), m_Specific(Op0))))
815 else if (match(Op0, m_FSub(m_AnyZero(), m_Specific(Op1))))
818 Instruction *FSub = cast<Instruction>(SubOp);
819 if ((FMF.noNaNs() || FSub->hasNoNaNs()) &&
820 (FMF.noInfs() || FSub->hasNoInfs()))
821 return Constant::getNullValue(Op0->getType());
827 /// Given operands for an FSub, see if we can fold the result. If not, this
829 static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
830 const Query &Q, unsigned MaxRecurse) {
831 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
832 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
833 Constant *Ops[] = { CLHS, CRHS };
834 return ConstantFoldInstOperands(Instruction::FSub, CLHS->getType(),
840 if (match(Op1, m_Zero()))
843 // fsub X, -0 ==> X, when we know X is not -0
844 if (match(Op1, m_NegZero()) &&
845 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
848 // fsub 0, (fsub -0.0, X) ==> X
850 if (match(Op0, m_AnyZero())) {
851 if (match(Op1, m_FSub(m_NegZero(), m_Value(X))))
853 if (FMF.noSignedZeros() && match(Op1, m_FSub(m_AnyZero(), m_Value(X))))
857 // fsub nnan x, x ==> 0.0
858 if (FMF.noNaNs() && Op0 == Op1)
859 return Constant::getNullValue(Op0->getType());
864 /// Given the operands for an FMul, see if we can fold the result
865 static Value *SimplifyFMulInst(Value *Op0, Value *Op1,
868 unsigned MaxRecurse) {
869 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
870 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
871 Constant *Ops[] = { CLHS, CRHS };
872 return ConstantFoldInstOperands(Instruction::FMul, CLHS->getType(),
876 // Canonicalize the constant to the RHS.
881 if (match(Op1, m_FPOne()))
884 // fmul nnan nsz X, 0 ==> 0
885 if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZero()))
891 /// Given operands for a Mul, see if we can fold the result.
892 /// If not, this returns null.
893 static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q,
894 unsigned MaxRecurse) {
895 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
896 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
897 Constant *Ops[] = { CLHS, CRHS };
898 return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(),
902 // Canonicalize the constant to the RHS.
907 if (match(Op1, m_Undef()))
908 return Constant::getNullValue(Op0->getType());
911 if (match(Op1, m_Zero()))
915 if (match(Op1, m_One()))
918 // (X / Y) * Y -> X if the division is exact.
920 if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y
921 match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y)
925 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
926 if (Value *V = SimplifyAndInst(Op0, Op1, Q, MaxRecurse-1))
929 // Try some generic simplifications for associative operations.
930 if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, Q,
934 // Mul distributes over Add. Try some generic simplifications based on this.
935 if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add,
939 // If the operation is with the result of a select instruction, check whether
940 // operating on either branch of the select always yields the same value.
941 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
942 if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, Q,
946 // If the operation is with the result of a phi instruction, check whether
947 // operating on all incoming values of the phi always yields the same value.
948 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
949 if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, Q,
956 Value *llvm::SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
957 const DataLayout &DL,
958 const TargetLibraryInfo *TLI,
959 const DominatorTree *DT, AssumptionCache *AC,
960 const Instruction *CxtI) {
961 return ::SimplifyFAddInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
965 Value *llvm::SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
966 const DataLayout &DL,
967 const TargetLibraryInfo *TLI,
968 const DominatorTree *DT, AssumptionCache *AC,
969 const Instruction *CxtI) {
970 return ::SimplifyFSubInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
974 Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF,
975 const DataLayout &DL,
976 const TargetLibraryInfo *TLI,
977 const DominatorTree *DT, AssumptionCache *AC,
978 const Instruction *CxtI) {
979 return ::SimplifyFMulInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
983 Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const DataLayout &DL,
984 const TargetLibraryInfo *TLI,
985 const DominatorTree *DT, AssumptionCache *AC,
986 const Instruction *CxtI) {
987 return ::SimplifyMulInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
991 /// Given operands for an SDiv or UDiv, see if we can fold the result.
992 /// If not, this returns null.
993 static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
994 const Query &Q, unsigned MaxRecurse) {
995 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
996 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
997 Constant *Ops[] = { C0, C1 };
998 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI);
1002 bool isSigned = Opcode == Instruction::SDiv;
1004 // X / undef -> undef
1005 if (match(Op1, m_Undef()))
1008 // X / 0 -> undef, we don't need to preserve faults!
1009 if (match(Op1, m_Zero()))
1010 return UndefValue::get(Op1->getType());
1013 if (match(Op0, m_Undef()))
1014 return Constant::getNullValue(Op0->getType());
1016 // 0 / X -> 0, we don't need to preserve faults!
1017 if (match(Op0, m_Zero()))
1021 if (match(Op1, m_One()))
1024 if (Op0->getType()->isIntegerTy(1))
1025 // It can't be division by zero, hence it must be division by one.
1030 return ConstantInt::get(Op0->getType(), 1);
1032 // (X * Y) / Y -> X if the multiplication does not overflow.
1033 Value *X = nullptr, *Y = nullptr;
1034 if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
1035 if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
1036 OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0);
1037 // If the Mul knows it does not overflow, then we are good to go.
1038 if ((isSigned && Mul->hasNoSignedWrap()) ||
1039 (!isSigned && Mul->hasNoUnsignedWrap()))
1041 // If X has the form X = A / Y then X * Y cannot overflow.
1042 if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X))
1043 if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y)
1047 // (X rem Y) / Y -> 0
1048 if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
1049 (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
1050 return Constant::getNullValue(Op0->getType());
1052 // (X /u C1) /u C2 -> 0 if C1 * C2 overflow
1053 ConstantInt *C1, *C2;
1054 if (!isSigned && match(Op0, m_UDiv(m_Value(X), m_ConstantInt(C1))) &&
1055 match(Op1, m_ConstantInt(C2))) {
1057 C1->getValue().umul_ov(C2->getValue(), Overflow);
1059 return Constant::getNullValue(Op0->getType());
1062 // If the operation is with the result of a select instruction, check whether
1063 // operating on either branch of the select always yields the same value.
1064 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1065 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1068 // If the operation is with the result of a phi instruction, check whether
1069 // operating on all incoming values of the phi always yields the same value.
1070 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1071 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1077 /// Given operands for an SDiv, see if we can fold the result.
1078 /// If not, this returns null.
1079 static Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q,
1080 unsigned MaxRecurse) {
1081 if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse))
1087 Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const DataLayout &DL,
1088 const TargetLibraryInfo *TLI,
1089 const DominatorTree *DT, AssumptionCache *AC,
1090 const Instruction *CxtI) {
1091 return ::SimplifySDivInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
1095 /// Given operands for a UDiv, see if we can fold the result.
1096 /// If not, this returns null.
1097 static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q,
1098 unsigned MaxRecurse) {
1099 if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse))
1105 Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const DataLayout &DL,
1106 const TargetLibraryInfo *TLI,
1107 const DominatorTree *DT, AssumptionCache *AC,
1108 const Instruction *CxtI) {
1109 return ::SimplifyUDivInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
1113 static Value *SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1114 const Query &Q, unsigned) {
1115 // undef / X -> undef (the undef could be a snan).
1116 if (match(Op0, m_Undef()))
1119 // X / undef -> undef
1120 if (match(Op1, m_Undef()))
1124 // Requires that NaNs are off (X could be zero) and signed zeroes are
1125 // ignored (X could be positive or negative, so the output sign is unknown).
1126 if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero()))
1130 // X / X -> 1.0 is legal when NaNs are ignored.
1132 return ConstantFP::get(Op0->getType(), 1.0);
1134 // -X / X -> -1.0 and
1135 // X / -X -> -1.0 are legal when NaNs are ignored.
1136 // We can ignore signed zeros because +-0.0/+-0.0 is NaN and ignored.
1137 if ((BinaryOperator::isFNeg(Op0, /*IgnoreZeroSign=*/true) &&
1138 BinaryOperator::getFNegArgument(Op0) == Op1) ||
1139 (BinaryOperator::isFNeg(Op1, /*IgnoreZeroSign=*/true) &&
1140 BinaryOperator::getFNegArgument(Op1) == Op0))
1141 return ConstantFP::get(Op0->getType(), -1.0);
1147 Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1148 const DataLayout &DL,
1149 const TargetLibraryInfo *TLI,
1150 const DominatorTree *DT, AssumptionCache *AC,
1151 const Instruction *CxtI) {
1152 return ::SimplifyFDivInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
1156 /// Given operands for an SRem or URem, see if we can fold the result.
1157 /// If not, this returns null.
1158 static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
1159 const Query &Q, unsigned MaxRecurse) {
1160 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1161 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1162 Constant *Ops[] = { C0, C1 };
1163 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI);
1167 // X % undef -> undef
1168 if (match(Op1, m_Undef()))
1172 if (match(Op0, m_Undef()))
1173 return Constant::getNullValue(Op0->getType());
1175 // 0 % X -> 0, we don't need to preserve faults!
1176 if (match(Op0, m_Zero()))
1179 // X % 0 -> undef, we don't need to preserve faults!
1180 if (match(Op1, m_Zero()))
1181 return UndefValue::get(Op0->getType());
1184 if (match(Op1, m_One()))
1185 return Constant::getNullValue(Op0->getType());
1187 if (Op0->getType()->isIntegerTy(1))
1188 // It can't be remainder by zero, hence it must be remainder by one.
1189 return Constant::getNullValue(Op0->getType());
1193 return Constant::getNullValue(Op0->getType());
1195 // (X % Y) % Y -> X % Y
1196 if ((Opcode == Instruction::SRem &&
1197 match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
1198 (Opcode == Instruction::URem &&
1199 match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
1202 // If the operation is with the result of a select instruction, check whether
1203 // operating on either branch of the select always yields the same value.
1204 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1205 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1208 // If the operation is with the result of a phi instruction, check whether
1209 // operating on all incoming values of the phi always yields the same value.
1210 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1211 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1217 /// Given operands for an SRem, see if we can fold the result.
1218 /// If not, this returns null.
1219 static Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q,
1220 unsigned MaxRecurse) {
1221 if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse))
1227 Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const DataLayout &DL,
1228 const TargetLibraryInfo *TLI,
1229 const DominatorTree *DT, AssumptionCache *AC,
1230 const Instruction *CxtI) {
1231 return ::SimplifySRemInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
1235 /// Given operands for a URem, see if we can fold the result.
1236 /// If not, this returns null.
1237 static Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q,
1238 unsigned MaxRecurse) {
1239 if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse))
1245 Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const DataLayout &DL,
1246 const TargetLibraryInfo *TLI,
1247 const DominatorTree *DT, AssumptionCache *AC,
1248 const Instruction *CxtI) {
1249 return ::SimplifyURemInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
1253 static Value *SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1254 const Query &, unsigned) {
1255 // undef % X -> undef (the undef could be a snan).
1256 if (match(Op0, m_Undef()))
1259 // X % undef -> undef
1260 if (match(Op1, m_Undef()))
1264 // Requires that NaNs are off (X could be zero) and signed zeroes are
1265 // ignored (X could be positive or negative, so the output sign is unknown).
1266 if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero()))
1272 Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1273 const DataLayout &DL,
1274 const TargetLibraryInfo *TLI,
1275 const DominatorTree *DT, AssumptionCache *AC,
1276 const Instruction *CxtI) {
1277 return ::SimplifyFRemInst(Op0, Op1, FMF, Query(DL, TLI, DT, AC, CxtI),
1281 /// Returns true if a shift by \c Amount always yields undef.
1282 static bool isUndefShift(Value *Amount) {
1283 Constant *C = dyn_cast<Constant>(Amount);
1287 // X shift by undef -> undef because it may shift by the bitwidth.
1288 if (isa<UndefValue>(C))
1291 // Shifting by the bitwidth or more is undefined.
1292 if (ConstantInt *CI = dyn_cast<ConstantInt>(C))
1293 if (CI->getValue().getLimitedValue() >=
1294 CI->getType()->getScalarSizeInBits())
1297 // If all lanes of a vector shift are undefined the whole shift is.
1298 if (isa<ConstantVector>(C) || isa<ConstantDataVector>(C)) {
1299 for (unsigned I = 0, E = C->getType()->getVectorNumElements(); I != E; ++I)
1300 if (!isUndefShift(C->getAggregateElement(I)))
1308 /// Given operands for an Shl, LShr or AShr, see if we can fold the result.
1309 /// If not, this returns null.
1310 static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
1311 const Query &Q, unsigned MaxRecurse) {
1312 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1313 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1314 Constant *Ops[] = { C0, C1 };
1315 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.DL, Q.TLI);
1319 // 0 shift by X -> 0
1320 if (match(Op0, m_Zero()))
1323 // X shift by 0 -> X
1324 if (match(Op1, m_Zero()))
1327 // Fold undefined shifts.
1328 if (isUndefShift(Op1))
1329 return UndefValue::get(Op0->getType());
1331 // If the operation is with the result of a select instruction, check whether
1332 // operating on either branch of the select always yields the same value.
1333 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1334 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1337 // If the operation is with the result of a phi instruction, check whether
1338 // operating on all incoming values of the phi always yields the same value.
1339 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1340 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1346 /// \brief Given operands for an Shl, LShr or AShr, see if we can
1347 /// fold the result. If not, this returns null.
1348 static Value *SimplifyRightShift(unsigned Opcode, Value *Op0, Value *Op1,
1349 bool isExact, const Query &Q,
1350 unsigned MaxRecurse) {
1351 if (Value *V = SimplifyShift(Opcode, Op0, Op1, Q, MaxRecurse))
1356 return Constant::getNullValue(Op0->getType());
1359 // undef >> X -> undef (if it's exact)
1360 if (match(Op0, m_Undef()))
1361 return isExact ? Op0 : Constant::getNullValue(Op0->getType());
1363 // The low bit cannot be shifted out of an exact shift if it is set.
1365 unsigned BitWidth = Op0->getType()->getScalarSizeInBits();
1366 APInt Op0KnownZero(BitWidth, 0);
1367 APInt Op0KnownOne(BitWidth, 0);
1368 computeKnownBits(Op0, Op0KnownZero, Op0KnownOne, Q.DL, /*Depth=*/0, Q.AC,
1377 /// Given operands for an Shl, see if we can fold the result.
1378 /// If not, this returns null.
1379 static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1380 const Query &Q, unsigned MaxRecurse) {
1381 if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse))
1385 // undef << X -> undef if (if it's NSW/NUW)
1386 if (match(Op0, m_Undef()))
1387 return isNSW || isNUW ? Op0 : Constant::getNullValue(Op0->getType());
1389 // (X >> A) << A -> X
1391 if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1)))))
1396 Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1397 const DataLayout &DL, const TargetLibraryInfo *TLI,
1398 const DominatorTree *DT, AssumptionCache *AC,
1399 const Instruction *CxtI) {
1400 return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query(DL, TLI, DT, AC, CxtI),
1404 /// Given operands for an LShr, see if we can fold the result.
1405 /// If not, this returns null.
1406 static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1407 const Query &Q, unsigned MaxRecurse) {
1408 if (Value *V = SimplifyRightShift(Instruction::LShr, Op0, Op1, isExact, Q,
1412 // (X << A) >> A -> X
1414 if (match(Op0, m_NUWShl(m_Value(X), m_Specific(Op1))))
1420 Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1421 const DataLayout &DL,
1422 const TargetLibraryInfo *TLI,
1423 const DominatorTree *DT, AssumptionCache *AC,
1424 const Instruction *CxtI) {
1425 return ::SimplifyLShrInst(Op0, Op1, isExact, Query(DL, TLI, DT, AC, CxtI),
1429 /// Given operands for an AShr, see if we can fold the result.
1430 /// If not, this returns null.
1431 static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1432 const Query &Q, unsigned MaxRecurse) {
1433 if (Value *V = SimplifyRightShift(Instruction::AShr, Op0, Op1, isExact, Q,
1437 // all ones >>a X -> all ones
1438 if (match(Op0, m_AllOnes()))
1441 // (X << A) >> A -> X
1443 if (match(Op0, m_NSWShl(m_Value(X), m_Specific(Op1))))
1446 // Arithmetic shifting an all-sign-bit value is a no-op.
1447 unsigned NumSignBits = ComputeNumSignBits(Op0, Q.DL, 0, Q.AC, Q.CxtI, Q.DT);
1448 if (NumSignBits == Op0->getType()->getScalarSizeInBits())
1454 Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1455 const DataLayout &DL,
1456 const TargetLibraryInfo *TLI,
1457 const DominatorTree *DT, AssumptionCache *AC,
1458 const Instruction *CxtI) {
1459 return ::SimplifyAShrInst(Op0, Op1, isExact, Query(DL, TLI, DT, AC, CxtI),
1463 static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
1464 ICmpInst *UnsignedICmp, bool IsAnd) {
1467 ICmpInst::Predicate EqPred;
1468 if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) ||
1469 !ICmpInst::isEquality(EqPred))
1472 ICmpInst::Predicate UnsignedPred;
1473 if (match(UnsignedICmp, m_ICmp(UnsignedPred, m_Value(X), m_Specific(Y))) &&
1474 ICmpInst::isUnsigned(UnsignedPred))
1476 else if (match(UnsignedICmp,
1477 m_ICmp(UnsignedPred, m_Value(Y), m_Specific(X))) &&
1478 ICmpInst::isUnsigned(UnsignedPred))
1479 UnsignedPred = ICmpInst::getSwappedPredicate(UnsignedPred);
1483 // X < Y && Y != 0 --> X < Y
1484 // X < Y || Y != 0 --> Y != 0
1485 if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_NE)
1486 return IsAnd ? UnsignedICmp : ZeroICmp;
1488 // X >= Y || Y != 0 --> true
1489 // X >= Y || Y == 0 --> X >= Y
1490 if (UnsignedPred == ICmpInst::ICMP_UGE && !IsAnd) {
1491 if (EqPred == ICmpInst::ICMP_NE)
1492 return getTrue(UnsignedICmp->getType());
1493 return UnsignedICmp;
1496 // X < Y && Y == 0 --> false
1497 if (UnsignedPred == ICmpInst::ICMP_ULT && EqPred == ICmpInst::ICMP_EQ &&
1499 return getFalse(UnsignedICmp->getType());
1504 /// Simplify (and (icmp ...) (icmp ...)) to true when we can tell that the range
1505 /// of possible values cannot be satisfied.
1506 static Value *SimplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
1507 ICmpInst::Predicate Pred0, Pred1;
1508 ConstantInt *CI1, *CI2;
1511 if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
1514 if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)),
1515 m_ConstantInt(CI2))))
1518 if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Specific(CI1))))
1521 Type *ITy = Op0->getType();
1523 auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
1524 bool isNSW = AddInst->hasNoSignedWrap();
1525 bool isNUW = AddInst->hasNoUnsignedWrap();
1527 const APInt &CI1V = CI1->getValue();
1528 const APInt &CI2V = CI2->getValue();
1529 const APInt Delta = CI2V - CI1V;
1530 if (CI1V.isStrictlyPositive()) {
1532 if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_SGT)
1533 return getFalse(ITy);
1534 if (Pred0 == ICmpInst::ICMP_SLT && Pred1 == ICmpInst::ICMP_SGT && isNSW)
1535 return getFalse(ITy);
1538 if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_SGT)
1539 return getFalse(ITy);
1540 if (Pred0 == ICmpInst::ICMP_SLE && Pred1 == ICmpInst::ICMP_SGT && isNSW)
1541 return getFalse(ITy);
1544 if (CI1V.getBoolValue() && isNUW) {
1546 if (Pred0 == ICmpInst::ICMP_ULT && Pred1 == ICmpInst::ICMP_UGT)
1547 return getFalse(ITy);
1549 if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGT)
1550 return getFalse(ITy);
1556 /// Given operands for an And, see if we can fold the result.
1557 /// If not, this returns null.
1558 static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q,
1559 unsigned MaxRecurse) {
1560 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1561 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1562 Constant *Ops[] = { CLHS, CRHS };
1563 return ConstantFoldInstOperands(Instruction::And, CLHS->getType(),
1567 // Canonicalize the constant to the RHS.
1568 std::swap(Op0, Op1);
1572 if (match(Op1, m_Undef()))
1573 return Constant::getNullValue(Op0->getType());
1580 if (match(Op1, m_Zero()))
1584 if (match(Op1, m_AllOnes()))
1587 // A & ~A = ~A & A = 0
1588 if (match(Op0, m_Not(m_Specific(Op1))) ||
1589 match(Op1, m_Not(m_Specific(Op0))))
1590 return Constant::getNullValue(Op0->getType());
1593 Value *A = nullptr, *B = nullptr;
1594 if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
1595 (A == Op1 || B == Op1))
1599 if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
1600 (A == Op0 || B == Op0))
1603 // A & (-A) = A if A is a power of two or zero.
1604 if (match(Op0, m_Neg(m_Specific(Op1))) ||
1605 match(Op1, m_Neg(m_Specific(Op0)))) {
1606 if (isKnownToBeAPowerOfTwo(Op0, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI,
1609 if (isKnownToBeAPowerOfTwo(Op1, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI,
1614 if (auto *ICILHS = dyn_cast<ICmpInst>(Op0)) {
1615 if (auto *ICIRHS = dyn_cast<ICmpInst>(Op1)) {
1616 if (Value *V = SimplifyAndOfICmps(ICILHS, ICIRHS))
1618 if (Value *V = SimplifyAndOfICmps(ICIRHS, ICILHS))
1623 // Try some generic simplifications for associative operations.
1624 if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q,
1628 // And distributes over Or. Try some generic simplifications based on this.
1629 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or,
1633 // And distributes over Xor. Try some generic simplifications based on this.
1634 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor,
1638 // If the operation is with the result of a select instruction, check whether
1639 // operating on either branch of the select always yields the same value.
1640 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1641 if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, Q,
1645 // If the operation is with the result of a phi instruction, check whether
1646 // operating on all incoming values of the phi always yields the same value.
1647 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1648 if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, Q,
1655 Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const DataLayout &DL,
1656 const TargetLibraryInfo *TLI,
1657 const DominatorTree *DT, AssumptionCache *AC,
1658 const Instruction *CxtI) {
1659 return ::SimplifyAndInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
1663 /// Simplify (or (icmp ...) (icmp ...)) to true when we can tell that the union
1664 /// contains all possible values.
1665 static Value *SimplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
1666 ICmpInst::Predicate Pred0, Pred1;
1667 ConstantInt *CI1, *CI2;
1670 if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
1673 if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_ConstantInt(CI1)),
1674 m_ConstantInt(CI2))))
1677 if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Specific(CI1))))
1680 Type *ITy = Op0->getType();
1682 auto *AddInst = cast<BinaryOperator>(Op0->getOperand(0));
1683 bool isNSW = AddInst->hasNoSignedWrap();
1684 bool isNUW = AddInst->hasNoUnsignedWrap();
1686 const APInt &CI1V = CI1->getValue();
1687 const APInt &CI2V = CI2->getValue();
1688 const APInt Delta = CI2V - CI1V;
1689 if (CI1V.isStrictlyPositive()) {
1691 if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_SLE)
1692 return getTrue(ITy);
1693 if (Pred0 == ICmpInst::ICMP_SGE && Pred1 == ICmpInst::ICMP_SLE && isNSW)
1694 return getTrue(ITy);
1697 if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_SLE)
1698 return getTrue(ITy);
1699 if (Pred0 == ICmpInst::ICMP_SGT && Pred1 == ICmpInst::ICMP_SLE && isNSW)
1700 return getTrue(ITy);
1703 if (CI1V.getBoolValue() && isNUW) {
1705 if (Pred0 == ICmpInst::ICMP_UGE && Pred1 == ICmpInst::ICMP_ULE)
1706 return getTrue(ITy);
1708 if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_ULE)
1709 return getTrue(ITy);
1715 /// Given operands for an Or, see if we can fold the result.
1716 /// If not, this returns null.
1717 static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q,
1718 unsigned MaxRecurse) {
1719 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1720 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1721 Constant *Ops[] = { CLHS, CRHS };
1722 return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(),
1726 // Canonicalize the constant to the RHS.
1727 std::swap(Op0, Op1);
1731 if (match(Op1, m_Undef()))
1732 return Constant::getAllOnesValue(Op0->getType());
1739 if (match(Op1, m_Zero()))
1743 if (match(Op1, m_AllOnes()))
1746 // A | ~A = ~A | A = -1
1747 if (match(Op0, m_Not(m_Specific(Op1))) ||
1748 match(Op1, m_Not(m_Specific(Op0))))
1749 return Constant::getAllOnesValue(Op0->getType());
1752 Value *A = nullptr, *B = nullptr;
1753 if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
1754 (A == Op1 || B == Op1))
1758 if (match(Op1, m_And(m_Value(A), m_Value(B))) &&
1759 (A == Op0 || B == Op0))
1762 // ~(A & ?) | A = -1
1763 if (match(Op0, m_Not(m_And(m_Value(A), m_Value(B)))) &&
1764 (A == Op1 || B == Op1))
1765 return Constant::getAllOnesValue(Op1->getType());
1767 // A | ~(A & ?) = -1
1768 if (match(Op1, m_Not(m_And(m_Value(A), m_Value(B)))) &&
1769 (A == Op0 || B == Op0))
1770 return Constant::getAllOnesValue(Op0->getType());
1772 if (auto *ICILHS = dyn_cast<ICmpInst>(Op0)) {
1773 if (auto *ICIRHS = dyn_cast<ICmpInst>(Op1)) {
1774 if (Value *V = SimplifyOrOfICmps(ICILHS, ICIRHS))
1776 if (Value *V = SimplifyOrOfICmps(ICIRHS, ICILHS))
1781 // Try some generic simplifications for associative operations.
1782 if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q,
1786 // Or distributes over And. Try some generic simplifications based on this.
1787 if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, Q,
1791 // If the operation is with the result of a select instruction, check whether
1792 // operating on either branch of the select always yields the same value.
1793 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1794 if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, Q,
1799 Value *C = nullptr, *D = nullptr;
1800 if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
1801 match(Op1, m_And(m_Value(B), m_Value(D)))) {
1802 ConstantInt *C1 = dyn_cast<ConstantInt>(C);
1803 ConstantInt *C2 = dyn_cast<ConstantInt>(D);
1804 if (C1 && C2 && (C1->getValue() == ~C2->getValue())) {
1805 // (A & C1)|(B & C2)
1806 // If we have: ((V + N) & C1) | (V & C2)
1807 // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
1808 // replace with V+N.
1810 if ((C2->getValue() & (C2->getValue() + 1)) == 0 && // C2 == 0+1+
1811 match(A, m_Add(m_Value(V1), m_Value(V2)))) {
1812 // Add commutes, try both ways.
1814 MaskedValueIsZero(V2, C2->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
1817 MaskedValueIsZero(V1, C2->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
1820 // Or commutes, try both ways.
1821 if ((C1->getValue() & (C1->getValue() + 1)) == 0 &&
1822 match(B, m_Add(m_Value(V1), m_Value(V2)))) {
1823 // Add commutes, try both ways.
1825 MaskedValueIsZero(V2, C1->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
1828 MaskedValueIsZero(V1, C1->getValue(), Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
1834 // If the operation is with the result of a phi instruction, check whether
1835 // operating on all incoming values of the phi always yields the same value.
1836 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1837 if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse))
1843 Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const DataLayout &DL,
1844 const TargetLibraryInfo *TLI,
1845 const DominatorTree *DT, AssumptionCache *AC,
1846 const Instruction *CxtI) {
1847 return ::SimplifyOrInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
1851 /// Given operands for a Xor, see if we can fold the result.
1852 /// If not, this returns null.
1853 static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q,
1854 unsigned MaxRecurse) {
1855 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1856 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1857 Constant *Ops[] = { CLHS, CRHS };
1858 return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(),
1862 // Canonicalize the constant to the RHS.
1863 std::swap(Op0, Op1);
1866 // A ^ undef -> undef
1867 if (match(Op1, m_Undef()))
1871 if (match(Op1, m_Zero()))
1876 return Constant::getNullValue(Op0->getType());
1878 // A ^ ~A = ~A ^ A = -1
1879 if (match(Op0, m_Not(m_Specific(Op1))) ||
1880 match(Op1, m_Not(m_Specific(Op0))))
1881 return Constant::getAllOnesValue(Op0->getType());
1883 // Try some generic simplifications for associative operations.
1884 if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, Q,
1888 // Threading Xor over selects and phi nodes is pointless, so don't bother.
1889 // Threading over the select in "A ^ select(cond, B, C)" means evaluating
1890 // "A^B" and "A^C" and seeing if they are equal; but they are equal if and
1891 // only if B and C are equal. If B and C are equal then (since we assume
1892 // that operands have already been simplified) "select(cond, B, C)" should
1893 // have been simplified to the common value of B and C already. Analysing
1894 // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
1895 // for threading over phi nodes.
1900 Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const DataLayout &DL,
1901 const TargetLibraryInfo *TLI,
1902 const DominatorTree *DT, AssumptionCache *AC,
1903 const Instruction *CxtI) {
1904 return ::SimplifyXorInst(Op0, Op1, Query(DL, TLI, DT, AC, CxtI),
1908 static Type *GetCompareTy(Value *Op) {
1909 return CmpInst::makeCmpResultType(Op->getType());
1912 /// Rummage around inside V looking for something equivalent to the comparison
1913 /// "LHS Pred RHS". Return such a value if found, otherwise return null.
1914 /// Helper function for analyzing max/min idioms.
1915 static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred,
1916 Value *LHS, Value *RHS) {
1917 SelectInst *SI = dyn_cast<SelectInst>(V);
1920 CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
1923 Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1);
1924 if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS)
1926 if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) &&
1927 LHS == CmpRHS && RHS == CmpLHS)
1932 // A significant optimization not implemented here is assuming that alloca
1933 // addresses are not equal to incoming argument values. They don't *alias*,
1934 // as we say, but that doesn't mean they aren't equal, so we take a
1935 // conservative approach.
1937 // This is inspired in part by C++11 5.10p1:
1938 // "Two pointers of the same type compare equal if and only if they are both
1939 // null, both point to the same function, or both represent the same
1942 // This is pretty permissive.
1944 // It's also partly due to C11 6.5.9p6:
1945 // "Two pointers compare equal if and only if both are null pointers, both are
1946 // pointers to the same object (including a pointer to an object and a
1947 // subobject at its beginning) or function, both are pointers to one past the
1948 // last element of the same array object, or one is a pointer to one past the
1949 // end of one array object and the other is a pointer to the start of a
1950 // different array object that happens to immediately follow the first array
1951 // object in the address space.)
1953 // C11's version is more restrictive, however there's no reason why an argument
1954 // couldn't be a one-past-the-end value for a stack object in the caller and be
1955 // equal to the beginning of a stack object in the callee.
1957 // If the C and C++ standards are ever made sufficiently restrictive in this
1958 // area, it may be possible to update LLVM's semantics accordingly and reinstate
1959 // this optimization.
1960 static Constant *computePointerICmp(const DataLayout &DL,
1961 const TargetLibraryInfo *TLI,
1962 CmpInst::Predicate Pred, Value *LHS,
1964 // First, skip past any trivial no-ops.
1965 LHS = LHS->stripPointerCasts();
1966 RHS = RHS->stripPointerCasts();
1968 // A non-null pointer is not equal to a null pointer.
1969 if (llvm::isKnownNonNull(LHS, TLI) && isa<ConstantPointerNull>(RHS) &&
1970 (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE))
1971 return ConstantInt::get(GetCompareTy(LHS),
1972 !CmpInst::isTrueWhenEqual(Pred));
1974 // We can only fold certain predicates on pointer comparisons.
1979 // Equality comaprisons are easy to fold.
1980 case CmpInst::ICMP_EQ:
1981 case CmpInst::ICMP_NE:
1984 // We can only handle unsigned relational comparisons because 'inbounds' on
1985 // a GEP only protects against unsigned wrapping.
1986 case CmpInst::ICMP_UGT:
1987 case CmpInst::ICMP_UGE:
1988 case CmpInst::ICMP_ULT:
1989 case CmpInst::ICMP_ULE:
1990 // However, we have to switch them to their signed variants to handle
1991 // negative indices from the base pointer.
1992 Pred = ICmpInst::getSignedPredicate(Pred);
1996 // Strip off any constant offsets so that we can reason about them.
1997 // It's tempting to use getUnderlyingObject or even just stripInBoundsOffsets
1998 // here and compare base addresses like AliasAnalysis does, however there are
1999 // numerous hazards. AliasAnalysis and its utilities rely on special rules
2000 // governing loads and stores which don't apply to icmps. Also, AliasAnalysis
2001 // doesn't need to guarantee pointer inequality when it says NoAlias.
2002 Constant *LHSOffset = stripAndComputeConstantOffsets(DL, LHS);
2003 Constant *RHSOffset = stripAndComputeConstantOffsets(DL, RHS);
2005 // If LHS and RHS are related via constant offsets to the same base
2006 // value, we can replace it with an icmp which just compares the offsets.
2008 return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset);
2010 // Various optimizations for (in)equality comparisons.
2011 if (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE) {
2012 // Different non-empty allocations that exist at the same time have
2013 // different addresses (if the program can tell). Global variables always
2014 // exist, so they always exist during the lifetime of each other and all
2015 // allocas. Two different allocas usually have different addresses...
2017 // However, if there's an @llvm.stackrestore dynamically in between two
2018 // allocas, they may have the same address. It's tempting to reduce the
2019 // scope of the problem by only looking at *static* allocas here. That would
2020 // cover the majority of allocas while significantly reducing the likelihood
2021 // of having an @llvm.stackrestore pop up in the middle. However, it's not
2022 // actually impossible for an @llvm.stackrestore to pop up in the middle of
2023 // an entry block. Also, if we have a block that's not attached to a
2024 // function, we can't tell if it's "static" under the current definition.
2025 // Theoretically, this problem could be fixed by creating a new kind of
2026 // instruction kind specifically for static allocas. Such a new instruction
2027 // could be required to be at the top of the entry block, thus preventing it
2028 // from being subject to a @llvm.stackrestore. Instcombine could even
2029 // convert regular allocas into these special allocas. It'd be nifty.
2030 // However, until then, this problem remains open.
2032 // So, we'll assume that two non-empty allocas have different addresses
2035 // With all that, if the offsets are within the bounds of their allocations
2036 // (and not one-past-the-end! so we can't use inbounds!), and their
2037 // allocations aren't the same, the pointers are not equal.
2039 // Note that it's not necessary to check for LHS being a global variable
2040 // address, due to canonicalization and constant folding.
2041 if (isa<AllocaInst>(LHS) &&
2042 (isa<AllocaInst>(RHS) || isa<GlobalVariable>(RHS))) {
2043 ConstantInt *LHSOffsetCI = dyn_cast<ConstantInt>(LHSOffset);
2044 ConstantInt *RHSOffsetCI = dyn_cast<ConstantInt>(RHSOffset);
2045 uint64_t LHSSize, RHSSize;
2046 if (LHSOffsetCI && RHSOffsetCI &&
2047 getObjectSize(LHS, LHSSize, DL, TLI) &&
2048 getObjectSize(RHS, RHSSize, DL, TLI)) {
2049 const APInt &LHSOffsetValue = LHSOffsetCI->getValue();
2050 const APInt &RHSOffsetValue = RHSOffsetCI->getValue();
2051 if (!LHSOffsetValue.isNegative() &&
2052 !RHSOffsetValue.isNegative() &&
2053 LHSOffsetValue.ult(LHSSize) &&
2054 RHSOffsetValue.ult(RHSSize)) {
2055 return ConstantInt::get(GetCompareTy(LHS),
2056 !CmpInst::isTrueWhenEqual(Pred));
2060 // Repeat the above check but this time without depending on DataLayout
2061 // or being able to compute a precise size.
2062 if (!cast<PointerType>(LHS->getType())->isEmptyTy() &&
2063 !cast<PointerType>(RHS->getType())->isEmptyTy() &&
2064 LHSOffset->isNullValue() &&
2065 RHSOffset->isNullValue())
2066 return ConstantInt::get(GetCompareTy(LHS),
2067 !CmpInst::isTrueWhenEqual(Pred));
2070 // Even if an non-inbounds GEP occurs along the path we can still optimize
2071 // equality comparisons concerning the result. We avoid walking the whole
2072 // chain again by starting where the last calls to
2073 // stripAndComputeConstantOffsets left off and accumulate the offsets.
2074 Constant *LHSNoBound = stripAndComputeConstantOffsets(DL, LHS, true);
2075 Constant *RHSNoBound = stripAndComputeConstantOffsets(DL, RHS, true);
2077 return ConstantExpr::getICmp(Pred,
2078 ConstantExpr::getAdd(LHSOffset, LHSNoBound),
2079 ConstantExpr::getAdd(RHSOffset, RHSNoBound));
2081 // If one side of the equality comparison must come from a noalias call
2082 // (meaning a system memory allocation function), and the other side must
2083 // come from a pointer that cannot overlap with dynamically-allocated
2084 // memory within the lifetime of the current function (allocas, byval
2085 // arguments, globals), then determine the comparison result here.
2086 SmallVector<Value *, 8> LHSUObjs, RHSUObjs;
2087 GetUnderlyingObjects(LHS, LHSUObjs, DL);
2088 GetUnderlyingObjects(RHS, RHSUObjs, DL);
2090 // Is the set of underlying objects all noalias calls?
2091 auto IsNAC = [](SmallVectorImpl<Value *> &Objects) {
2092 return std::all_of(Objects.begin(), Objects.end(), isNoAliasCall);
2095 // Is the set of underlying objects all things which must be disjoint from
2096 // noalias calls. For allocas, we consider only static ones (dynamic
2097 // allocas might be transformed into calls to malloc not simultaneously
2098 // live with the compared-to allocation). For globals, we exclude symbols
2099 // that might be resolve lazily to symbols in another dynamically-loaded
2100 // library (and, thus, could be malloc'ed by the implementation).
2101 auto IsAllocDisjoint = [](SmallVectorImpl<Value *> &Objects) {
2102 return std::all_of(Objects.begin(), Objects.end(), [](Value *V) {
2103 if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
2104 return AI->getParent() && AI->getFunction() && AI->isStaticAlloca();
2105 if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
2106 return (GV->hasLocalLinkage() || GV->hasHiddenVisibility() ||
2107 GV->hasProtectedVisibility() || GV->hasUnnamedAddr()) &&
2108 !GV->isThreadLocal();
2109 if (const Argument *A = dyn_cast<Argument>(V))
2110 return A->hasByValAttr();
2115 if ((IsNAC(LHSUObjs) && IsAllocDisjoint(RHSUObjs)) ||
2116 (IsNAC(RHSUObjs) && IsAllocDisjoint(LHSUObjs)))
2117 return ConstantInt::get(GetCompareTy(LHS),
2118 !CmpInst::isTrueWhenEqual(Pred));
2125 /// Given operands for an ICmpInst, see if we can fold the result.
2126 /// If not, this returns null.
2127 static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2128 const Query &Q, unsigned MaxRecurse) {
2129 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
2130 assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
2132 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
2133 if (Constant *CRHS = dyn_cast<Constant>(RHS))
2134 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
2136 // If we have a constant, make sure it is on the RHS.
2137 std::swap(LHS, RHS);
2138 Pred = CmpInst::getSwappedPredicate(Pred);
2141 Type *ITy = GetCompareTy(LHS); // The return type.
2142 Type *OpTy = LHS->getType(); // The operand type.
2144 // icmp X, X -> true/false
2145 // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false
2146 // because X could be 0.
2147 if (LHS == RHS || isa<UndefValue>(RHS))
2148 return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
2150 // Special case logic when the operands have i1 type.
2151 if (OpTy->getScalarType()->isIntegerTy(1)) {
2154 case ICmpInst::ICMP_EQ:
2156 if (match(RHS, m_One()))
2159 case ICmpInst::ICMP_NE:
2161 if (match(RHS, m_Zero()))
2164 case ICmpInst::ICMP_UGT:
2166 if (match(RHS, m_Zero()))
2169 case ICmpInst::ICMP_UGE:
2171 if (match(RHS, m_One()))
2173 if (isImpliedCondition(RHS, LHS, Q.DL))
2174 return getTrue(ITy);
2176 case ICmpInst::ICMP_SGE:
2177 /// For signed comparison, the values for an i1 are 0 and -1
2178 /// respectively. This maps into a truth table of:
2179 /// LHS | RHS | LHS >=s RHS | LHS implies RHS
2180 /// 0 | 0 | 1 (0 >= 0) | 1
2181 /// 0 | 1 | 1 (0 >= -1) | 1
2182 /// 1 | 0 | 0 (-1 >= 0) | 0
2183 /// 1 | 1 | 1 (-1 >= -1) | 1
2184 if (isImpliedCondition(LHS, RHS, Q.DL))
2185 return getTrue(ITy);
2187 case ICmpInst::ICMP_SLT:
2189 if (match(RHS, m_Zero()))
2192 case ICmpInst::ICMP_SLE:
2194 if (match(RHS, m_One()))
2197 case ICmpInst::ICMP_ULE:
2198 if (isImpliedCondition(LHS, RHS, Q.DL))
2199 return getTrue(ITy);
2204 // If we are comparing with zero then try hard since this is a common case.
2205 if (match(RHS, m_Zero())) {
2206 bool LHSKnownNonNegative, LHSKnownNegative;
2208 default: llvm_unreachable("Unknown ICmp predicate!");
2209 case ICmpInst::ICMP_ULT:
2210 return getFalse(ITy);
2211 case ICmpInst::ICMP_UGE:
2212 return getTrue(ITy);
2213 case ICmpInst::ICMP_EQ:
2214 case ICmpInst::ICMP_ULE:
2215 if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2216 return getFalse(ITy);
2218 case ICmpInst::ICMP_NE:
2219 case ICmpInst::ICMP_UGT:
2220 if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2221 return getTrue(ITy);
2223 case ICmpInst::ICMP_SLT:
2224 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2226 if (LHSKnownNegative)
2227 return getTrue(ITy);
2228 if (LHSKnownNonNegative)
2229 return getFalse(ITy);
2231 case ICmpInst::ICMP_SLE:
2232 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2234 if (LHSKnownNegative)
2235 return getTrue(ITy);
2236 if (LHSKnownNonNegative &&
2237 isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2238 return getFalse(ITy);
2240 case ICmpInst::ICMP_SGE:
2241 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2243 if (LHSKnownNegative)
2244 return getFalse(ITy);
2245 if (LHSKnownNonNegative)
2246 return getTrue(ITy);
2248 case ICmpInst::ICMP_SGT:
2249 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2251 if (LHSKnownNegative)
2252 return getFalse(ITy);
2253 if (LHSKnownNonNegative &&
2254 isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2255 return getTrue(ITy);
2260 // See if we are doing a comparison with a constant integer.
2261 if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2262 // Rule out tautological comparisons (eg., ult 0 or uge 0).
2263 ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue());
2264 if (RHS_CR.isEmptySet())
2265 return ConstantInt::getFalse(CI->getContext());
2266 if (RHS_CR.isFullSet())
2267 return ConstantInt::getTrue(CI->getContext());
2269 // Many binary operators with constant RHS have easy to compute constant
2270 // range. Use them to check whether the comparison is a tautology.
2271 unsigned Width = CI->getBitWidth();
2272 APInt Lower = APInt(Width, 0);
2273 APInt Upper = APInt(Width, 0);
2275 if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) {
2276 // 'urem x, CI2' produces [0, CI2).
2277 Upper = CI2->getValue();
2278 } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) {
2279 // 'srem x, CI2' produces (-|CI2|, |CI2|).
2280 Upper = CI2->getValue().abs();
2281 Lower = (-Upper) + 1;
2282 } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) {
2283 // 'udiv CI2, x' produces [0, CI2].
2284 Upper = CI2->getValue() + 1;
2285 } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) {
2286 // 'udiv x, CI2' produces [0, UINT_MAX / CI2].
2287 APInt NegOne = APInt::getAllOnesValue(Width);
2289 Upper = NegOne.udiv(CI2->getValue()) + 1;
2290 } else if (match(LHS, m_SDiv(m_ConstantInt(CI2), m_Value()))) {
2291 if (CI2->isMinSignedValue()) {
2292 // 'sdiv INT_MIN, x' produces [INT_MIN, INT_MIN / -2].
2293 Lower = CI2->getValue();
2294 Upper = Lower.lshr(1) + 1;
2296 // 'sdiv CI2, x' produces [-|CI2|, |CI2|].
2297 Upper = CI2->getValue().abs() + 1;
2298 Lower = (-Upper) + 1;
2300 } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) {
2301 APInt IntMin = APInt::getSignedMinValue(Width);
2302 APInt IntMax = APInt::getSignedMaxValue(Width);
2303 APInt Val = CI2->getValue();
2304 if (Val.isAllOnesValue()) {
2305 // 'sdiv x, -1' produces [INT_MIN + 1, INT_MAX]
2306 // where CI2 != -1 and CI2 != 0 and CI2 != 1
2309 } else if (Val.countLeadingZeros() < Width - 1) {
2310 // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2]
2311 // where CI2 != -1 and CI2 != 0 and CI2 != 1
2312 Lower = IntMin.sdiv(Val);
2313 Upper = IntMax.sdiv(Val);
2314 if (Lower.sgt(Upper))
2315 std::swap(Lower, Upper);
2317 assert(Upper != Lower && "Upper part of range has wrapped!");
2319 } else if (match(LHS, m_NUWShl(m_ConstantInt(CI2), m_Value()))) {
2320 // 'shl nuw CI2, x' produces [CI2, CI2 << CLZ(CI2)]
2321 Lower = CI2->getValue();
2322 Upper = Lower.shl(Lower.countLeadingZeros()) + 1;
2323 } else if (match(LHS, m_NSWShl(m_ConstantInt(CI2), m_Value()))) {
2324 if (CI2->isNegative()) {
2325 // 'shl nsw CI2, x' produces [CI2 << CLO(CI2)-1, CI2]
2326 unsigned ShiftAmount = CI2->getValue().countLeadingOnes() - 1;
2327 Lower = CI2->getValue().shl(ShiftAmount);
2328 Upper = CI2->getValue() + 1;
2330 // 'shl nsw CI2, x' produces [CI2, CI2 << CLZ(CI2)-1]
2331 unsigned ShiftAmount = CI2->getValue().countLeadingZeros() - 1;
2332 Lower = CI2->getValue();
2333 Upper = CI2->getValue().shl(ShiftAmount) + 1;
2335 } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {
2336 // 'lshr x, CI2' produces [0, UINT_MAX >> CI2].
2337 APInt NegOne = APInt::getAllOnesValue(Width);
2338 if (CI2->getValue().ult(Width))
2339 Upper = NegOne.lshr(CI2->getValue()) + 1;
2340 } else if (match(LHS, m_LShr(m_ConstantInt(CI2), m_Value()))) {
2341 // 'lshr CI2, x' produces [CI2 >> (Width-1), CI2].
2342 unsigned ShiftAmount = Width - 1;
2343 if (!CI2->isZero() && cast<BinaryOperator>(LHS)->isExact())
2344 ShiftAmount = CI2->getValue().countTrailingZeros();
2345 Lower = CI2->getValue().lshr(ShiftAmount);
2346 Upper = CI2->getValue() + 1;
2347 } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) {
2348 // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2].
2349 APInt IntMin = APInt::getSignedMinValue(Width);
2350 APInt IntMax = APInt::getSignedMaxValue(Width);
2351 if (CI2->getValue().ult(Width)) {
2352 Lower = IntMin.ashr(CI2->getValue());
2353 Upper = IntMax.ashr(CI2->getValue()) + 1;
2355 } else if (match(LHS, m_AShr(m_ConstantInt(CI2), m_Value()))) {
2356 unsigned ShiftAmount = Width - 1;
2357 if (!CI2->isZero() && cast<BinaryOperator>(LHS)->isExact())
2358 ShiftAmount = CI2->getValue().countTrailingZeros();
2359 if (CI2->isNegative()) {
2360 // 'ashr CI2, x' produces [CI2, CI2 >> (Width-1)]
2361 Lower = CI2->getValue();
2362 Upper = CI2->getValue().ashr(ShiftAmount) + 1;
2364 // 'ashr CI2, x' produces [CI2 >> (Width-1), CI2]
2365 Lower = CI2->getValue().ashr(ShiftAmount);
2366 Upper = CI2->getValue() + 1;
2368 } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) {
2369 // 'or x, CI2' produces [CI2, UINT_MAX].
2370 Lower = CI2->getValue();
2371 } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) {
2372 // 'and x, CI2' produces [0, CI2].
2373 Upper = CI2->getValue() + 1;
2374 } else if (match(LHS, m_NUWAdd(m_Value(), m_ConstantInt(CI2)))) {
2375 // 'add nuw x, CI2' produces [CI2, UINT_MAX].
2376 Lower = CI2->getValue();
2379 ConstantRange LHS_CR = Lower != Upper ? ConstantRange(Lower, Upper)
2380 : ConstantRange(Width, true);
2382 if (auto *I = dyn_cast<Instruction>(LHS))
2383 if (auto *Ranges = I->getMetadata(LLVMContext::MD_range))
2384 LHS_CR = LHS_CR.intersectWith(getConstantRangeFromMetadata(*Ranges));
2386 if (!LHS_CR.isFullSet()) {
2387 if (RHS_CR.contains(LHS_CR))
2388 return ConstantInt::getTrue(RHS->getContext());
2389 if (RHS_CR.inverse().contains(LHS_CR))
2390 return ConstantInt::getFalse(RHS->getContext());
2394 // If both operands have range metadata, use the metadata
2395 // to simplify the comparison.
2396 if (isa<Instruction>(RHS) && isa<Instruction>(LHS)) {
2397 auto RHS_Instr = dyn_cast<Instruction>(RHS);
2398 auto LHS_Instr = dyn_cast<Instruction>(LHS);
2400 if (RHS_Instr->getMetadata(LLVMContext::MD_range) &&
2401 LHS_Instr->getMetadata(LLVMContext::MD_range)) {
2402 auto RHS_CR = getConstantRangeFromMetadata(
2403 *RHS_Instr->getMetadata(LLVMContext::MD_range));
2404 auto LHS_CR = getConstantRangeFromMetadata(
2405 *LHS_Instr->getMetadata(LLVMContext::MD_range));
2407 auto Satisfied_CR = ConstantRange::makeSatisfyingICmpRegion(Pred, RHS_CR);
2408 if (Satisfied_CR.contains(LHS_CR))
2409 return ConstantInt::getTrue(RHS->getContext());
2411 auto InversedSatisfied_CR = ConstantRange::makeSatisfyingICmpRegion(
2412 CmpInst::getInversePredicate(Pred), RHS_CR);
2413 if (InversedSatisfied_CR.contains(LHS_CR))
2414 return ConstantInt::getFalse(RHS->getContext());
2418 // Compare of cast, for example (zext X) != 0 -> X != 0
2419 if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
2420 Instruction *LI = cast<CastInst>(LHS);
2421 Value *SrcOp = LI->getOperand(0);
2422 Type *SrcTy = SrcOp->getType();
2423 Type *DstTy = LI->getType();
2425 // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
2426 // if the integer type is the same size as the pointer type.
2427 if (MaxRecurse && isa<PtrToIntInst>(LI) &&
2428 Q.DL.getTypeSizeInBits(SrcTy) == DstTy->getPrimitiveSizeInBits()) {
2429 if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
2430 // Transfer the cast to the constant.
2431 if (Value *V = SimplifyICmpInst(Pred, SrcOp,
2432 ConstantExpr::getIntToPtr(RHSC, SrcTy),
2435 } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) {
2436 if (RI->getOperand(0)->getType() == SrcTy)
2437 // Compare without the cast.
2438 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
2444 if (isa<ZExtInst>(LHS)) {
2445 // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
2447 if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) {
2448 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
2449 // Compare X and Y. Note that signed predicates become unsigned.
2450 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
2451 SrcOp, RI->getOperand(0), Q,
2455 // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
2456 // too. If not, then try to deduce the result of the comparison.
2457 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2458 // Compute the constant that would happen if we truncated to SrcTy then
2459 // reextended to DstTy.
2460 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
2461 Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy);
2463 // If the re-extended constant didn't change then this is effectively
2464 // also a case of comparing two zero-extended values.
2465 if (RExt == CI && MaxRecurse)
2466 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
2467 SrcOp, Trunc, Q, MaxRecurse-1))
2470 // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
2471 // there. Use this to work out the result of the comparison.
2474 default: llvm_unreachable("Unknown ICmp predicate!");
2476 case ICmpInst::ICMP_EQ:
2477 case ICmpInst::ICMP_UGT:
2478 case ICmpInst::ICMP_UGE:
2479 return ConstantInt::getFalse(CI->getContext());
2481 case ICmpInst::ICMP_NE:
2482 case ICmpInst::ICMP_ULT:
2483 case ICmpInst::ICMP_ULE:
2484 return ConstantInt::getTrue(CI->getContext());
2486 // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
2487 // is non-negative then LHS <s RHS.
2488 case ICmpInst::ICMP_SGT:
2489 case ICmpInst::ICMP_SGE:
2490 return CI->getValue().isNegative() ?
2491 ConstantInt::getTrue(CI->getContext()) :
2492 ConstantInt::getFalse(CI->getContext());
2494 case ICmpInst::ICMP_SLT:
2495 case ICmpInst::ICMP_SLE:
2496 return CI->getValue().isNegative() ?
2497 ConstantInt::getFalse(CI->getContext()) :
2498 ConstantInt::getTrue(CI->getContext());
2504 if (isa<SExtInst>(LHS)) {
2505 // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
2507 if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) {
2508 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
2509 // Compare X and Y. Note that the predicate does not change.
2510 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
2514 // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
2515 // too. If not, then try to deduce the result of the comparison.
2516 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2517 // Compute the constant that would happen if we truncated to SrcTy then
2518 // reextended to DstTy.
2519 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
2520 Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy);
2522 // If the re-extended constant didn't change then this is effectively
2523 // also a case of comparing two sign-extended values.
2524 if (RExt == CI && MaxRecurse)
2525 if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1))
2528 // Otherwise the upper bits of LHS are all equal, while RHS has varying
2529 // bits there. Use this to work out the result of the comparison.
2532 default: llvm_unreachable("Unknown ICmp predicate!");
2533 case ICmpInst::ICMP_EQ:
2534 return ConstantInt::getFalse(CI->getContext());
2535 case ICmpInst::ICMP_NE:
2536 return ConstantInt::getTrue(CI->getContext());
2538 // If RHS is non-negative then LHS <s RHS. If RHS is negative then
2540 case ICmpInst::ICMP_SGT:
2541 case ICmpInst::ICMP_SGE:
2542 return CI->getValue().isNegative() ?
2543 ConstantInt::getTrue(CI->getContext()) :
2544 ConstantInt::getFalse(CI->getContext());
2545 case ICmpInst::ICMP_SLT:
2546 case ICmpInst::ICMP_SLE:
2547 return CI->getValue().isNegative() ?
2548 ConstantInt::getFalse(CI->getContext()) :
2549 ConstantInt::getTrue(CI->getContext());
2551 // If LHS is non-negative then LHS <u RHS. If LHS is negative then
2553 case ICmpInst::ICMP_UGT:
2554 case ICmpInst::ICMP_UGE:
2555 // Comparison is true iff the LHS <s 0.
2557 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
2558 Constant::getNullValue(SrcTy),
2562 case ICmpInst::ICMP_ULT:
2563 case ICmpInst::ICMP_ULE:
2564 // Comparison is true iff the LHS >=s 0.
2566 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
2567 Constant::getNullValue(SrcTy),
2577 // icmp eq|ne X, Y -> false|true if X != Y
2578 if ((Pred == ICmpInst::ICMP_EQ || Pred == ICmpInst::ICMP_NE) &&
2579 isKnownNonEqual(LHS, RHS, Q.DL, Q.AC, Q.CxtI, Q.DT)) {
2580 LLVMContext &Ctx = LHS->getType()->getContext();
2581 return Pred == ICmpInst::ICMP_NE ?
2582 ConstantInt::getTrue(Ctx) : ConstantInt::getFalse(Ctx);
2585 // Special logic for binary operators.
2586 BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS);
2587 BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
2588 if (MaxRecurse && (LBO || RBO)) {
2589 // Analyze the case when either LHS or RHS is an add instruction.
2590 Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr;
2591 // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
2592 bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
2593 if (LBO && LBO->getOpcode() == Instruction::Add) {
2594 A = LBO->getOperand(0); B = LBO->getOperand(1);
2595 NoLHSWrapProblem = ICmpInst::isEquality(Pred) ||
2596 (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) ||
2597 (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap());
2599 if (RBO && RBO->getOpcode() == Instruction::Add) {
2600 C = RBO->getOperand(0); D = RBO->getOperand(1);
2601 NoRHSWrapProblem = ICmpInst::isEquality(Pred) ||
2602 (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) ||
2603 (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap());
2606 // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
2607 if ((A == RHS || B == RHS) && NoLHSWrapProblem)
2608 if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A,
2609 Constant::getNullValue(RHS->getType()),
2613 // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
2614 if ((C == LHS || D == LHS) && NoRHSWrapProblem)
2615 if (Value *V = SimplifyICmpInst(Pred,
2616 Constant::getNullValue(LHS->getType()),
2617 C == LHS ? D : C, Q, MaxRecurse-1))
2620 // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
2621 if (A && C && (A == C || A == D || B == C || B == D) &&
2622 NoLHSWrapProblem && NoRHSWrapProblem) {
2623 // Determine Y and Z in the form icmp (X+Y), (X+Z).
2626 // C + B == C + D -> B == D
2629 } else if (A == D) {
2630 // D + B == C + D -> B == C
2633 } else if (B == C) {
2634 // A + C == C + D -> A == D
2639 // A + D == C + D -> A == C
2643 if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))
2648 // icmp pred (or X, Y), X
2649 if (LBO && match(LBO, m_CombineOr(m_Or(m_Value(), m_Specific(RHS)),
2650 m_Or(m_Specific(RHS), m_Value())))) {
2651 if (Pred == ICmpInst::ICMP_ULT)
2652 return getFalse(ITy);
2653 if (Pred == ICmpInst::ICMP_UGE)
2654 return getTrue(ITy);
2656 // icmp pred X, (or X, Y)
2657 if (RBO && match(RBO, m_CombineOr(m_Or(m_Value(), m_Specific(LHS)),
2658 m_Or(m_Specific(LHS), m_Value())))) {
2659 if (Pred == ICmpInst::ICMP_ULE)
2660 return getTrue(ITy);
2661 if (Pred == ICmpInst::ICMP_UGT)
2662 return getFalse(ITy);
2665 // icmp pred (and X, Y), X
2666 if (LBO && match(LBO, m_CombineOr(m_And(m_Value(), m_Specific(RHS)),
2667 m_And(m_Specific(RHS), m_Value())))) {
2668 if (Pred == ICmpInst::ICMP_UGT)
2669 return getFalse(ITy);
2670 if (Pred == ICmpInst::ICMP_ULE)
2671 return getTrue(ITy);
2673 // icmp pred X, (and X, Y)
2674 if (RBO && match(RBO, m_CombineOr(m_And(m_Value(), m_Specific(LHS)),
2675 m_And(m_Specific(LHS), m_Value())))) {
2676 if (Pred == ICmpInst::ICMP_UGE)
2677 return getTrue(ITy);
2678 if (Pred == ICmpInst::ICMP_ULT)
2679 return getFalse(ITy);
2682 // 0 - (zext X) pred C
2683 if (!CmpInst::isUnsigned(Pred) && match(LHS, m_Neg(m_ZExt(m_Value())))) {
2684 if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS)) {
2685 if (RHSC->getValue().isStrictlyPositive()) {
2686 if (Pred == ICmpInst::ICMP_SLT)
2687 return ConstantInt::getTrue(RHSC->getContext());
2688 if (Pred == ICmpInst::ICMP_SGE)
2689 return ConstantInt::getFalse(RHSC->getContext());
2690 if (Pred == ICmpInst::ICMP_EQ)
2691 return ConstantInt::getFalse(RHSC->getContext());
2692 if (Pred == ICmpInst::ICMP_NE)
2693 return ConstantInt::getTrue(RHSC->getContext());
2695 if (RHSC->getValue().isNonNegative()) {
2696 if (Pred == ICmpInst::ICMP_SLE)
2697 return ConstantInt::getTrue(RHSC->getContext());
2698 if (Pred == ICmpInst::ICMP_SGT)
2699 return ConstantInt::getFalse(RHSC->getContext());
2704 // icmp pred (urem X, Y), Y
2705 if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
2706 bool KnownNonNegative, KnownNegative;
2710 case ICmpInst::ICMP_SGT:
2711 case ICmpInst::ICMP_SGE:
2712 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2714 if (!KnownNonNegative)
2717 case ICmpInst::ICMP_EQ:
2718 case ICmpInst::ICMP_UGT:
2719 case ICmpInst::ICMP_UGE:
2720 return getFalse(ITy);
2721 case ICmpInst::ICMP_SLT:
2722 case ICmpInst::ICMP_SLE:
2723 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2725 if (!KnownNonNegative)
2728 case ICmpInst::ICMP_NE:
2729 case ICmpInst::ICMP_ULT:
2730 case ICmpInst::ICMP_ULE:
2731 return getTrue(ITy);
2735 // icmp pred X, (urem Y, X)
2736 if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
2737 bool KnownNonNegative, KnownNegative;
2741 case ICmpInst::ICMP_SGT:
2742 case ICmpInst::ICMP_SGE:
2743 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2745 if (!KnownNonNegative)
2748 case ICmpInst::ICMP_NE:
2749 case ICmpInst::ICMP_UGT:
2750 case ICmpInst::ICMP_UGE:
2751 return getTrue(ITy);
2752 case ICmpInst::ICMP_SLT:
2753 case ICmpInst::ICMP_SLE:
2754 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2756 if (!KnownNonNegative)
2759 case ICmpInst::ICMP_EQ:
2760 case ICmpInst::ICMP_ULT:
2761 case ICmpInst::ICMP_ULE:
2762 return getFalse(ITy);
2767 if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) {
2768 // icmp pred (X /u Y), X
2769 if (Pred == ICmpInst::ICMP_UGT)
2770 return getFalse(ITy);
2771 if (Pred == ICmpInst::ICMP_ULE)
2772 return getTrue(ITy);
2779 // where CI2 is a power of 2 and CI isn't
2780 if (auto *CI = dyn_cast<ConstantInt>(RHS)) {
2781 const APInt *CI2Val, *CIVal = &CI->getValue();
2782 if (LBO && match(LBO, m_Shl(m_APInt(CI2Val), m_Value())) &&
2783 CI2Val->isPowerOf2()) {
2784 if (!CIVal->isPowerOf2()) {
2785 // CI2 << X can equal zero in some circumstances,
2786 // this simplification is unsafe if CI is zero.
2788 // We know it is safe if:
2789 // - The shift is nsw, we can't shift out the one bit.
2790 // - The shift is nuw, we can't shift out the one bit.
2793 if (LBO->hasNoSignedWrap() || LBO->hasNoUnsignedWrap() ||
2794 *CI2Val == 1 || !CI->isZero()) {
2795 if (Pred == ICmpInst::ICMP_EQ)
2796 return ConstantInt::getFalse(RHS->getContext());
2797 if (Pred == ICmpInst::ICMP_NE)
2798 return ConstantInt::getTrue(RHS->getContext());
2801 if (CIVal->isSignBit() && *CI2Val == 1) {
2802 if (Pred == ICmpInst::ICMP_UGT)
2803 return ConstantInt::getFalse(RHS->getContext());
2804 if (Pred == ICmpInst::ICMP_ULE)
2805 return ConstantInt::getTrue(RHS->getContext());
2810 if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
2811 LBO->getOperand(1) == RBO->getOperand(1)) {
2812 switch (LBO->getOpcode()) {
2814 case Instruction::UDiv:
2815 case Instruction::LShr:
2816 if (ICmpInst::isSigned(Pred))
2819 case Instruction::SDiv:
2820 case Instruction::AShr:
2821 if (!LBO->isExact() || !RBO->isExact())
2823 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2824 RBO->getOperand(0), Q, MaxRecurse-1))
2827 case Instruction::Shl: {
2828 bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap();
2829 bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap();
2832 if (!NSW && ICmpInst::isSigned(Pred))
2834 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2835 RBO->getOperand(0), Q, MaxRecurse-1))
2842 // Simplify comparisons involving max/min.
2844 CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
2845 CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
2847 // Signed variants on "max(a,b)>=a -> true".
2848 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2849 if (A != RHS) std::swap(A, B); // smax(A, B) pred A.
2850 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2851 // We analyze this as smax(A, B) pred A.
2853 } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
2854 (A == LHS || B == LHS)) {
2855 if (A != LHS) std::swap(A, B); // A pred smax(A, B).
2856 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2857 // We analyze this as smax(A, B) swapped-pred A.
2858 P = CmpInst::getSwappedPredicate(Pred);
2859 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2860 (A == RHS || B == RHS)) {
2861 if (A != RHS) std::swap(A, B); // smin(A, B) pred A.
2862 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2863 // We analyze this as smax(-A, -B) swapped-pred -A.
2864 // Note that we do not need to actually form -A or -B thanks to EqP.
2865 P = CmpInst::getSwappedPredicate(Pred);
2866 } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
2867 (A == LHS || B == LHS)) {
2868 if (A != LHS) std::swap(A, B); // A pred smin(A, B).
2869 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2870 // We analyze this as smax(-A, -B) pred -A.
2871 // Note that we do not need to actually form -A or -B thanks to EqP.
2874 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2875 // Cases correspond to "max(A, B) p A".
2879 case CmpInst::ICMP_EQ:
2880 case CmpInst::ICMP_SLE:
2881 // Equivalent to "A EqP B". This may be the same as the condition tested
2882 // in the max/min; if so, we can just return that.
2883 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2885 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2887 // Otherwise, see if "A EqP B" simplifies.
2889 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2892 case CmpInst::ICMP_NE:
2893 case CmpInst::ICMP_SGT: {
2894 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2895 // Equivalent to "A InvEqP B". This may be the same as the condition
2896 // tested in the max/min; if so, we can just return that.
2897 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2899 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2901 // Otherwise, see if "A InvEqP B" simplifies.
2903 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2907 case CmpInst::ICMP_SGE:
2909 return getTrue(ITy);
2910 case CmpInst::ICMP_SLT:
2912 return getFalse(ITy);
2916 // Unsigned variants on "max(a,b)>=a -> true".
2917 P = CmpInst::BAD_ICMP_PREDICATE;
2918 if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2919 if (A != RHS) std::swap(A, B); // umax(A, B) pred A.
2920 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2921 // We analyze this as umax(A, B) pred A.
2923 } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
2924 (A == LHS || B == LHS)) {
2925 if (A != LHS) std::swap(A, B); // A pred umax(A, B).
2926 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2927 // We analyze this as umax(A, B) swapped-pred A.
2928 P = CmpInst::getSwappedPredicate(Pred);
2929 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
2930 (A == RHS || B == RHS)) {
2931 if (A != RHS) std::swap(A, B); // umin(A, B) pred A.
2932 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2933 // We analyze this as umax(-A, -B) swapped-pred -A.
2934 // Note that we do not need to actually form -A or -B thanks to EqP.
2935 P = CmpInst::getSwappedPredicate(Pred);
2936 } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
2937 (A == LHS || B == LHS)) {
2938 if (A != LHS) std::swap(A, B); // A pred umin(A, B).
2939 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2940 // We analyze this as umax(-A, -B) pred -A.
2941 // Note that we do not need to actually form -A or -B thanks to EqP.
2944 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2945 // Cases correspond to "max(A, B) p A".
2949 case CmpInst::ICMP_EQ:
2950 case CmpInst::ICMP_ULE:
2951 // Equivalent to "A EqP B". This may be the same as the condition tested
2952 // in the max/min; if so, we can just return that.
2953 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2955 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2957 // Otherwise, see if "A EqP B" simplifies.
2959 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2962 case CmpInst::ICMP_NE:
2963 case CmpInst::ICMP_UGT: {
2964 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2965 // Equivalent to "A InvEqP B". This may be the same as the condition
2966 // tested in the max/min; if so, we can just return that.
2967 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2969 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2971 // Otherwise, see if "A InvEqP B" simplifies.
2973 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2977 case CmpInst::ICMP_UGE:
2979 return getTrue(ITy);
2980 case CmpInst::ICMP_ULT:
2982 return getFalse(ITy);
2986 // Variants on "max(x,y) >= min(x,z)".
2988 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) &&
2989 match(RHS, m_SMin(m_Value(C), m_Value(D))) &&
2990 (A == C || A == D || B == C || B == D)) {
2991 // max(x, ?) pred min(x, ?).
2992 if (Pred == CmpInst::ICMP_SGE)
2994 return getTrue(ITy);
2995 if (Pred == CmpInst::ICMP_SLT)
2997 return getFalse(ITy);
2998 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2999 match(RHS, m_SMax(m_Value(C), m_Value(D))) &&
3000 (A == C || A == D || B == C || B == D)) {
3001 // min(x, ?) pred max(x, ?).
3002 if (Pred == CmpInst::ICMP_SLE)
3004 return getTrue(ITy);
3005 if (Pred == CmpInst::ICMP_SGT)
3007 return getFalse(ITy);
3008 } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) &&
3009 match(RHS, m_UMin(m_Value(C), m_Value(D))) &&
3010 (A == C || A == D || B == C || B == D)) {
3011 // max(x, ?) pred min(x, ?).
3012 if (Pred == CmpInst::ICMP_UGE)
3014 return getTrue(ITy);
3015 if (Pred == CmpInst::ICMP_ULT)
3017 return getFalse(ITy);
3018 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
3019 match(RHS, m_UMax(m_Value(C), m_Value(D))) &&
3020 (A == C || A == D || B == C || B == D)) {
3021 // min(x, ?) pred max(x, ?).
3022 if (Pred == CmpInst::ICMP_ULE)
3024 return getTrue(ITy);
3025 if (Pred == CmpInst::ICMP_UGT)
3027 return getFalse(ITy);
3030 // Simplify comparisons of related pointers using a powerful, recursive
3031 // GEP-walk when we have target data available..
3032 if (LHS->getType()->isPointerTy())
3033 if (Constant *C = computePointerICmp(Q.DL, Q.TLI, Pred, LHS, RHS))
3036 if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) {
3037 if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) {
3038 if (GLHS->getPointerOperand() == GRHS->getPointerOperand() &&
3039 GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() &&
3040 (ICmpInst::isEquality(Pred) ||
3041 (GLHS->isInBounds() && GRHS->isInBounds() &&
3042 Pred == ICmpInst::getSignedPredicate(Pred)))) {
3043 // The bases are equal and the indices are constant. Build a constant
3044 // expression GEP with the same indices and a null base pointer to see
3045 // what constant folding can make out of it.
3046 Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType());
3047 SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end());
3048 Constant *NewLHS = ConstantExpr::getGetElementPtr(
3049 GLHS->getSourceElementType(), Null, IndicesLHS);
3051 SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end());
3052 Constant *NewRHS = ConstantExpr::getGetElementPtr(
3053 GLHS->getSourceElementType(), Null, IndicesRHS);
3054 return ConstantExpr::getICmp(Pred, NewLHS, NewRHS);
3059 // If a bit is known to be zero for A and known to be one for B,
3060 // then A and B cannot be equal.
3061 if (ICmpInst::isEquality(Pred)) {
3062 if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
3063 uint32_t BitWidth = CI->getBitWidth();
3064 APInt LHSKnownZero(BitWidth, 0);
3065 APInt LHSKnownOne(BitWidth, 0);
3066 computeKnownBits(LHS, LHSKnownZero, LHSKnownOne, Q.DL, /*Depth=*/0, Q.AC,
3068 const APInt &RHSVal = CI->getValue();
3069 if (((LHSKnownZero & RHSVal) != 0) || ((LHSKnownOne & ~RHSVal) != 0))
3070 return Pred == ICmpInst::ICMP_EQ
3071 ? ConstantInt::getFalse(CI->getContext())
3072 : ConstantInt::getTrue(CI->getContext());
3076 // If the comparison is with the result of a select instruction, check whether
3077 // comparing with either branch of the select always yields the same value.
3078 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
3079 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
3082 // If the comparison is with the result of a phi instruction, check whether
3083 // doing the compare with each incoming phi value yields a common result.
3084 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3085 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
3091 Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3092 const DataLayout &DL,
3093 const TargetLibraryInfo *TLI,
3094 const DominatorTree *DT, AssumptionCache *AC,
3095 const Instruction *CxtI) {
3096 return ::SimplifyICmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
3100 /// Given operands for an FCmpInst, see if we can fold the result.
3101 /// If not, this returns null.
3102 static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3103 FastMathFlags FMF, const Query &Q,
3104 unsigned MaxRecurse) {
3105 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
3106 assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
3108 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
3109 if (Constant *CRHS = dyn_cast<Constant>(RHS))
3110 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
3112 // If we have a constant, make sure it is on the RHS.
3113 std::swap(LHS, RHS);
3114 Pred = CmpInst::getSwappedPredicate(Pred);
3117 // Fold trivial predicates.
3118 if (Pred == FCmpInst::FCMP_FALSE)
3119 return ConstantInt::get(GetCompareTy(LHS), 0);
3120 if (Pred == FCmpInst::FCMP_TRUE)
3121 return ConstantInt::get(GetCompareTy(LHS), 1);
3123 // UNO/ORD predicates can be trivially folded if NaNs are ignored.
3125 if (Pred == FCmpInst::FCMP_UNO)
3126 return ConstantInt::get(GetCompareTy(LHS), 0);
3127 if (Pred == FCmpInst::FCMP_ORD)
3128 return ConstantInt::get(GetCompareTy(LHS), 1);
3131 // fcmp pred x, undef and fcmp pred undef, x
3132 // fold to true if unordered, false if ordered
3133 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS)) {
3134 // Choosing NaN for the undef will always make unordered comparison succeed
3135 // and ordered comparison fail.
3136 return ConstantInt::get(GetCompareTy(LHS), CmpInst::isUnordered(Pred));
3139 // fcmp x,x -> true/false. Not all compares are foldable.
3141 if (CmpInst::isTrueWhenEqual(Pred))
3142 return ConstantInt::get(GetCompareTy(LHS), 1);
3143 if (CmpInst::isFalseWhenEqual(Pred))
3144 return ConstantInt::get(GetCompareTy(LHS), 0);
3147 // Handle fcmp with constant RHS
3148 if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHS)) {
3149 // If the constant is a nan, see if we can fold the comparison based on it.
3150 if (CFP->getValueAPF().isNaN()) {
3151 if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo"
3152 return ConstantInt::getFalse(CFP->getContext());
3153 assert(FCmpInst::isUnordered(Pred) &&
3154 "Comparison must be either ordered or unordered!");
3155 // True if unordered.
3156 return ConstantInt::getTrue(CFP->getContext());
3158 // Check whether the constant is an infinity.
3159 if (CFP->getValueAPF().isInfinity()) {
3160 if (CFP->getValueAPF().isNegative()) {
3162 case FCmpInst::FCMP_OLT:
3163 // No value is ordered and less than negative infinity.
3164 return ConstantInt::getFalse(CFP->getContext());
3165 case FCmpInst::FCMP_UGE:
3166 // All values are unordered with or at least negative infinity.
3167 return ConstantInt::getTrue(CFP->getContext());
3173 case FCmpInst::FCMP_OGT:
3174 // No value is ordered and greater than infinity.
3175 return ConstantInt::getFalse(CFP->getContext());
3176 case FCmpInst::FCMP_ULE:
3177 // All values are unordered with and at most infinity.
3178 return ConstantInt::getTrue(CFP->getContext());
3184 if (CFP->getValueAPF().isZero()) {
3186 case FCmpInst::FCMP_UGE:
3187 if (CannotBeOrderedLessThanZero(LHS))
3188 return ConstantInt::getTrue(CFP->getContext());
3190 case FCmpInst::FCMP_OLT:
3192 if (CannotBeOrderedLessThanZero(LHS))
3193 return ConstantInt::getFalse(CFP->getContext());
3201 // If the comparison is with the result of a select instruction, check whether
3202 // comparing with either branch of the select always yields the same value.
3203 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
3204 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
3207 // If the comparison is with the result of a phi instruction, check whether
3208 // doing the compare with each incoming phi value yields a common result.
3209 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3210 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
3216 Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3217 FastMathFlags FMF, const DataLayout &DL,
3218 const TargetLibraryInfo *TLI,
3219 const DominatorTree *DT, AssumptionCache *AC,
3220 const Instruction *CxtI) {
3221 return ::SimplifyFCmpInst(Predicate, LHS, RHS, FMF,
3222 Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3225 /// See if V simplifies when its operand Op is replaced with RepOp.
3226 static const Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
3228 unsigned MaxRecurse) {
3229 // Trivial replacement.
3233 auto *I = dyn_cast<Instruction>(V);
3237 // If this is a binary operator, try to simplify it with the replaced op.
3238 if (auto *B = dyn_cast<BinaryOperator>(I)) {
3240 // %cmp = icmp eq i32 %x, 2147483647
3241 // %add = add nsw i32 %x, 1
3242 // %sel = select i1 %cmp, i32 -2147483648, i32 %add
3244 // We can't replace %sel with %add unless we strip away the flags.
3245 if (isa<OverflowingBinaryOperator>(B))
3246 if (B->hasNoSignedWrap() || B->hasNoUnsignedWrap())
3248 if (isa<PossiblyExactOperator>(B))
3253 if (B->getOperand(0) == Op)
3254 return SimplifyBinOp(B->getOpcode(), RepOp, B->getOperand(1), Q,
3256 if (B->getOperand(1) == Op)
3257 return SimplifyBinOp(B->getOpcode(), B->getOperand(0), RepOp, Q,
3262 // Same for CmpInsts.
3263 if (CmpInst *C = dyn_cast<CmpInst>(I)) {
3265 if (C->getOperand(0) == Op)
3266 return SimplifyCmpInst(C->getPredicate(), RepOp, C->getOperand(1), Q,
3268 if (C->getOperand(1) == Op)
3269 return SimplifyCmpInst(C->getPredicate(), C->getOperand(0), RepOp, Q,
3274 // TODO: We could hand off more cases to instsimplify here.
3276 // If all operands are constant after substituting Op for RepOp then we can
3277 // constant fold the instruction.
3278 if (Constant *CRepOp = dyn_cast<Constant>(RepOp)) {
3279 // Build a list of all constant operands.
3280 SmallVector<Constant *, 8> ConstOps;
3281 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
3282 if (I->getOperand(i) == Op)
3283 ConstOps.push_back(CRepOp);
3284 else if (Constant *COp = dyn_cast<Constant>(I->getOperand(i)))
3285 ConstOps.push_back(COp);
3290 // All operands were constants, fold it.
3291 if (ConstOps.size() == I->getNumOperands()) {
3292 if (CmpInst *C = dyn_cast<CmpInst>(I))
3293 return ConstantFoldCompareInstOperands(C->getPredicate(), ConstOps[0],
3294 ConstOps[1], Q.DL, Q.TLI);
3296 if (LoadInst *LI = dyn_cast<LoadInst>(I))
3297 if (!LI->isVolatile())
3298 return ConstantFoldLoadFromConstPtr(ConstOps[0], Q.DL);
3300 return ConstantFoldInstOperands(I->getOpcode(), I->getType(), ConstOps,
3308 /// Given operands for a SelectInst, see if we can fold the result.
3309 /// If not, this returns null.
3310 static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
3311 Value *FalseVal, const Query &Q,
3312 unsigned MaxRecurse) {
3313 // select true, X, Y -> X
3314 // select false, X, Y -> Y
3315 if (Constant *CB = dyn_cast<Constant>(CondVal)) {
3316 if (CB->isAllOnesValue())
3318 if (CB->isNullValue())
3322 // select C, X, X -> X
3323 if (TrueVal == FalseVal)
3326 if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
3327 if (isa<Constant>(TrueVal))
3331 if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
3333 if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
3336 if (const auto *ICI = dyn_cast<ICmpInst>(CondVal)) {
3337 unsigned BitWidth = Q.DL.getTypeSizeInBits(TrueVal->getType());
3338 ICmpInst::Predicate Pred = ICI->getPredicate();
3339 Value *CmpLHS = ICI->getOperand(0);
3340 Value *CmpRHS = ICI->getOperand(1);
3341 APInt MinSignedValue = APInt::getSignBit(BitWidth);
3345 bool IsBitTest = false;
3346 if (ICmpInst::isEquality(Pred) &&
3347 match(CmpLHS, m_And(m_Value(X), m_APInt(Y))) &&
3348 match(CmpRHS, m_Zero())) {
3350 TrueWhenUnset = Pred == ICmpInst::ICMP_EQ;
3351 } else if (Pred == ICmpInst::ICMP_SLT && match(CmpRHS, m_Zero())) {
3353 Y = &MinSignedValue;
3355 TrueWhenUnset = false;
3356 } else if (Pred == ICmpInst::ICMP_SGT && match(CmpRHS, m_AllOnes())) {
3358 Y = &MinSignedValue;
3360 TrueWhenUnset = true;
3364 // (X & Y) == 0 ? X & ~Y : X --> X
3365 // (X & Y) != 0 ? X & ~Y : X --> X & ~Y
3366 if (FalseVal == X && match(TrueVal, m_And(m_Specific(X), m_APInt(C))) &&
3368 return TrueWhenUnset ? FalseVal : TrueVal;
3369 // (X & Y) == 0 ? X : X & ~Y --> X & ~Y
3370 // (X & Y) != 0 ? X : X & ~Y --> X
3371 if (TrueVal == X && match(FalseVal, m_And(m_Specific(X), m_APInt(C))) &&
3373 return TrueWhenUnset ? FalseVal : TrueVal;
3375 if (Y->isPowerOf2()) {
3376 // (X & Y) == 0 ? X | Y : X --> X | Y
3377 // (X & Y) != 0 ? X | Y : X --> X
3378 if (FalseVal == X && match(TrueVal, m_Or(m_Specific(X), m_APInt(C))) &&
3380 return TrueWhenUnset ? TrueVal : FalseVal;
3381 // (X & Y) == 0 ? X : X | Y --> X
3382 // (X & Y) != 0 ? X : X | Y --> X | Y
3383 if (TrueVal == X && match(FalseVal, m_Or(m_Specific(X), m_APInt(C))) &&
3385 return TrueWhenUnset ? TrueVal : FalseVal;
3388 if (ICI->hasOneUse()) {
3390 if (match(CmpRHS, m_APInt(C))) {
3391 // X < MIN ? T : F --> F
3392 if (Pred == ICmpInst::ICMP_SLT && C->isMinSignedValue())
3394 // X < MIN ? T : F --> F
3395 if (Pred == ICmpInst::ICMP_ULT && C->isMinValue())
3397 // X > MAX ? T : F --> F
3398 if (Pred == ICmpInst::ICMP_SGT && C->isMaxSignedValue())
3400 // X > MAX ? T : F --> F
3401 if (Pred == ICmpInst::ICMP_UGT && C->isMaxValue())
3406 // If we have an equality comparison then we know the value in one of the
3407 // arms of the select. See if substituting this value into the arm and
3408 // simplifying the result yields the same value as the other arm.
3409 if (Pred == ICmpInst::ICMP_EQ) {
3410 if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3412 SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3415 if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3417 SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3420 } else if (Pred == ICmpInst::ICMP_NE) {
3421 if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3423 SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3426 if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3428 SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3437 Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
3438 const DataLayout &DL,
3439 const TargetLibraryInfo *TLI,
3440 const DominatorTree *DT, AssumptionCache *AC,
3441 const Instruction *CxtI) {
3442 return ::SimplifySelectInst(Cond, TrueVal, FalseVal,
3443 Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3446 /// Given operands for an GetElementPtrInst, see if we can fold the result.
3447 /// If not, this returns null.
3448 static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops,
3449 const Query &Q, unsigned) {
3450 // The type of the GEP pointer operand.
3452 cast<PointerType>(Ops[0]->getType()->getScalarType())->getAddressSpace();
3454 // getelementptr P -> P.
3455 if (Ops.size() == 1)
3458 // Compute the (pointer) type returned by the GEP instruction.
3459 Type *LastType = GetElementPtrInst::getIndexedType(SrcTy, Ops.slice(1));
3460 Type *GEPTy = PointerType::get(LastType, AS);
3461 if (VectorType *VT = dyn_cast<VectorType>(Ops[0]->getType()))
3462 GEPTy = VectorType::get(GEPTy, VT->getNumElements());
3464 if (isa<UndefValue>(Ops[0]))
3465 return UndefValue::get(GEPTy);
3467 if (Ops.size() == 2) {
3468 // getelementptr P, 0 -> P.
3469 if (match(Ops[1], m_Zero()))
3473 if (Ty->isSized()) {
3476 uint64_t TyAllocSize = Q.DL.getTypeAllocSize(Ty);
3477 // getelementptr P, N -> P if P points to a type of zero size.
3478 if (TyAllocSize == 0)
3481 // The following transforms are only safe if the ptrtoint cast
3482 // doesn't truncate the pointers.
3483 if (Ops[1]->getType()->getScalarSizeInBits() ==
3484 Q.DL.getPointerSizeInBits(AS)) {
3485 auto PtrToIntOrZero = [GEPTy](Value *P) -> Value * {
3486 if (match(P, m_Zero()))
3487 return Constant::getNullValue(GEPTy);
3489 if (match(P, m_PtrToInt(m_Value(Temp))))
3490 if (Temp->getType() == GEPTy)
3495 // getelementptr V, (sub P, V) -> P if P points to a type of size 1.
3496 if (TyAllocSize == 1 &&
3497 match(Ops[1], m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0])))))
3498 if (Value *R = PtrToIntOrZero(P))
3501 // getelementptr V, (ashr (sub P, V), C) -> Q
3502 // if P points to a type of size 1 << C.
3504 m_AShr(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
3505 m_ConstantInt(C))) &&
3506 TyAllocSize == 1ULL << C)
3507 if (Value *R = PtrToIntOrZero(P))
3510 // getelementptr V, (sdiv (sub P, V), C) -> Q
3511 // if P points to a type of size C.
3513 m_SDiv(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
3514 m_SpecificInt(TyAllocSize))))
3515 if (Value *R = PtrToIntOrZero(P))
3521 // Check to see if this is constant foldable.
3522 for (unsigned i = 0, e = Ops.size(); i != e; ++i)
3523 if (!isa<Constant>(Ops[i]))
3526 return ConstantExpr::getGetElementPtr(SrcTy, cast<Constant>(Ops[0]),
3530 Value *llvm::SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout &DL,
3531 const TargetLibraryInfo *TLI,
3532 const DominatorTree *DT, AssumptionCache *AC,
3533 const Instruction *CxtI) {
3534 return ::SimplifyGEPInst(
3535 cast<PointerType>(Ops[0]->getType()->getScalarType())->getElementType(),
3536 Ops, Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3539 /// Given operands for an InsertValueInst, see if we can fold the result.
3540 /// If not, this returns null.
3541 static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
3542 ArrayRef<unsigned> Idxs, const Query &Q,
3544 if (Constant *CAgg = dyn_cast<Constant>(Agg))
3545 if (Constant *CVal = dyn_cast<Constant>(Val))
3546 return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs);
3548 // insertvalue x, undef, n -> x
3549 if (match(Val, m_Undef()))
3552 // insertvalue x, (extractvalue y, n), n
3553 if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val))
3554 if (EV->getAggregateOperand()->getType() == Agg->getType() &&
3555 EV->getIndices() == Idxs) {
3556 // insertvalue undef, (extractvalue y, n), n -> y
3557 if (match(Agg, m_Undef()))
3558 return EV->getAggregateOperand();
3560 // insertvalue y, (extractvalue y, n), n -> y
3561 if (Agg == EV->getAggregateOperand())
3568 Value *llvm::SimplifyInsertValueInst(
3569 Value *Agg, Value *Val, ArrayRef<unsigned> Idxs, const DataLayout &DL,
3570 const TargetLibraryInfo *TLI, const DominatorTree *DT, AssumptionCache *AC,
3571 const Instruction *CxtI) {
3572 return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query(DL, TLI, DT, AC, CxtI),
3576 /// Given operands for an ExtractValueInst, see if we can fold the result.
3577 /// If not, this returns null.
3578 static Value *SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
3579 const Query &, unsigned) {
3580 if (auto *CAgg = dyn_cast<Constant>(Agg))
3581 return ConstantFoldExtractValueInstruction(CAgg, Idxs);
3583 // extractvalue x, (insertvalue y, elt, n), n -> elt
3584 unsigned NumIdxs = Idxs.size();
3585 for (auto *IVI = dyn_cast<InsertValueInst>(Agg); IVI != nullptr;
3586 IVI = dyn_cast<InsertValueInst>(IVI->getAggregateOperand())) {
3587 ArrayRef<unsigned> InsertValueIdxs = IVI->getIndices();
3588 unsigned NumInsertValueIdxs = InsertValueIdxs.size();
3589 unsigned NumCommonIdxs = std::min(NumInsertValueIdxs, NumIdxs);
3590 if (InsertValueIdxs.slice(0, NumCommonIdxs) ==
3591 Idxs.slice(0, NumCommonIdxs)) {
3592 if (NumIdxs == NumInsertValueIdxs)
3593 return IVI->getInsertedValueOperand();
3601 Value *llvm::SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
3602 const DataLayout &DL,
3603 const TargetLibraryInfo *TLI,
3604 const DominatorTree *DT,
3605 AssumptionCache *AC,
3606 const Instruction *CxtI) {
3607 return ::SimplifyExtractValueInst(Agg, Idxs, Query(DL, TLI, DT, AC, CxtI),
3611 /// Given operands for an ExtractElementInst, see if we can fold the result.
3612 /// If not, this returns null.
3613 static Value *SimplifyExtractElementInst(Value *Vec, Value *Idx, const Query &,
3615 if (auto *CVec = dyn_cast<Constant>(Vec)) {
3616 if (auto *CIdx = dyn_cast<Constant>(Idx))
3617 return ConstantFoldExtractElementInstruction(CVec, CIdx);
3619 // The index is not relevant if our vector is a splat.
3620 if (auto *Splat = CVec->getSplatValue())
3623 if (isa<UndefValue>(Vec))
3624 return UndefValue::get(Vec->getType()->getVectorElementType());
3627 // If extracting a specified index from the vector, see if we can recursively
3628 // find a previously computed scalar that was inserted into the vector.
3629 if (auto *IdxC = dyn_cast<ConstantInt>(Idx))
3630 if (Value *Elt = findScalarElement(Vec, IdxC->getZExtValue()))
3636 Value *llvm::SimplifyExtractElementInst(
3637 Value *Vec, Value *Idx, const DataLayout &DL, const TargetLibraryInfo *TLI,
3638 const DominatorTree *DT, AssumptionCache *AC, const Instruction *CxtI) {
3639 return ::SimplifyExtractElementInst(Vec, Idx, Query(DL, TLI, DT, AC, CxtI),
3643 /// See if we can fold the given phi. If not, returns null.
3644 static Value *SimplifyPHINode(PHINode *PN, const Query &Q) {
3645 // If all of the PHI's incoming values are the same then replace the PHI node
3646 // with the common value.
3647 Value *CommonValue = nullptr;
3648 bool HasUndefInput = false;
3649 for (Value *Incoming : PN->incoming_values()) {
3650 // If the incoming value is the phi node itself, it can safely be skipped.
3651 if (Incoming == PN) continue;
3652 if (isa<UndefValue>(Incoming)) {
3653 // Remember that we saw an undef value, but otherwise ignore them.
3654 HasUndefInput = true;
3657 if (CommonValue && Incoming != CommonValue)
3658 return nullptr; // Not the same, bail out.
3659 CommonValue = Incoming;
3662 // If CommonValue is null then all of the incoming values were either undef or
3663 // equal to the phi node itself.
3665 return UndefValue::get(PN->getType());
3667 // If we have a PHI node like phi(X, undef, X), where X is defined by some
3668 // instruction, we cannot return X as the result of the PHI node unless it
3669 // dominates the PHI block.
3671 return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : nullptr;
3676 static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
3677 if (Constant *C = dyn_cast<Constant>(Op))
3678 return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.DL, Q.TLI);
3683 Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout &DL,
3684 const TargetLibraryInfo *TLI,
3685 const DominatorTree *DT, AssumptionCache *AC,
3686 const Instruction *CxtI) {
3687 return ::SimplifyTruncInst(Op, Ty, Query(DL, TLI, DT, AC, CxtI),
3691 //=== Helper functions for higher up the class hierarchy.
3693 /// Given operands for a BinaryOperator, see if we can fold the result.
3694 /// If not, this returns null.
3695 static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3696 const Query &Q, unsigned MaxRecurse) {
3698 case Instruction::Add:
3699 return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
3701 case Instruction::FAdd:
3702 return SimplifyFAddInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3704 case Instruction::Sub:
3705 return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
3707 case Instruction::FSub:
3708 return SimplifyFSubInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3710 case Instruction::Mul: return SimplifyMulInst (LHS, RHS, Q, MaxRecurse);
3711 case Instruction::FMul:
3712 return SimplifyFMulInst (LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3713 case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse);
3714 case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse);
3715 case Instruction::FDiv:
3716 return SimplifyFDivInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3717 case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse);
3718 case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse);
3719 case Instruction::FRem:
3720 return SimplifyFRemInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3721 case Instruction::Shl:
3722 return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
3724 case Instruction::LShr:
3725 return SimplifyLShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
3726 case Instruction::AShr:
3727 return SimplifyAShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
3728 case Instruction::And: return SimplifyAndInst(LHS, RHS, Q, MaxRecurse);
3729 case Instruction::Or: return SimplifyOrInst (LHS, RHS, Q, MaxRecurse);
3730 case Instruction::Xor: return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
3732 if (Constant *CLHS = dyn_cast<Constant>(LHS))
3733 if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
3734 Constant *COps[] = {CLHS, CRHS};
3735 return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.DL,
3739 // If the operation is associative, try some generic simplifications.
3740 if (Instruction::isAssociative(Opcode))
3741 if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse))
3744 // If the operation is with the result of a select instruction check whether
3745 // operating on either branch of the select always yields the same value.
3746 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
3747 if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse))
3750 // If the operation is with the result of a phi instruction, check whether
3751 // operating on all incoming values of the phi always yields the same value.
3752 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3753 if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
3760 /// Given operands for a BinaryOperator, see if we can fold the result.
3761 /// If not, this returns null.
3762 /// In contrast to SimplifyBinOp, try to use FastMathFlag when folding the
3763 /// result. In case we don't need FastMathFlags, simply fall to SimplifyBinOp.
3764 static Value *SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3765 const FastMathFlags &FMF, const Query &Q,
3766 unsigned MaxRecurse) {
3768 case Instruction::FAdd:
3769 return SimplifyFAddInst(LHS, RHS, FMF, Q, MaxRecurse);
3770 case Instruction::FSub:
3771 return SimplifyFSubInst(LHS, RHS, FMF, Q, MaxRecurse);
3772 case Instruction::FMul:
3773 return SimplifyFMulInst(LHS, RHS, FMF, Q, MaxRecurse);
3775 return SimplifyBinOp(Opcode, LHS, RHS, Q, MaxRecurse);
3779 Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3780 const DataLayout &DL, const TargetLibraryInfo *TLI,
3781 const DominatorTree *DT, AssumptionCache *AC,
3782 const Instruction *CxtI) {
3783 return ::SimplifyBinOp(Opcode, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
3787 Value *llvm::SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3788 const FastMathFlags &FMF, const DataLayout &DL,
3789 const TargetLibraryInfo *TLI,
3790 const DominatorTree *DT, AssumptionCache *AC,
3791 const Instruction *CxtI) {
3792 return ::SimplifyFPBinOp(Opcode, LHS, RHS, FMF, Query(DL, TLI, DT, AC, CxtI),
3796 /// Given operands for a CmpInst, see if we can fold the result.
3797 static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3798 const Query &Q, unsigned MaxRecurse) {
3799 if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
3800 return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
3801 return SimplifyFCmpInst(Predicate, LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3804 Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3805 const DataLayout &DL, const TargetLibraryInfo *TLI,
3806 const DominatorTree *DT, AssumptionCache *AC,
3807 const Instruction *CxtI) {
3808 return ::SimplifyCmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
3812 static bool IsIdempotent(Intrinsic::ID ID) {
3814 default: return false;
3816 // Unary idempotent: f(f(x)) = f(x)
3817 case Intrinsic::fabs:
3818 case Intrinsic::floor:
3819 case Intrinsic::ceil:
3820 case Intrinsic::trunc:
3821 case Intrinsic::rint:
3822 case Intrinsic::nearbyint:
3823 case Intrinsic::round:
3828 template <typename IterTy>
3829 static Value *SimplifyIntrinsic(Function *F, IterTy ArgBegin, IterTy ArgEnd,
3830 const Query &Q, unsigned MaxRecurse) {
3831 Intrinsic::ID IID = F->getIntrinsicID();
3832 unsigned NumOperands = std::distance(ArgBegin, ArgEnd);
3833 Type *ReturnType = F->getReturnType();
3836 if (NumOperands == 2) {
3837 Value *LHS = *ArgBegin;
3838 Value *RHS = *(ArgBegin + 1);
3839 if (IID == Intrinsic::usub_with_overflow ||
3840 IID == Intrinsic::ssub_with_overflow) {
3841 // X - X -> { 0, false }
3843 return Constant::getNullValue(ReturnType);
3845 // X - undef -> undef
3846 // undef - X -> undef
3847 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS))
3848 return UndefValue::get(ReturnType);
3851 if (IID == Intrinsic::uadd_with_overflow ||
3852 IID == Intrinsic::sadd_with_overflow) {
3853 // X + undef -> undef
3854 if (isa<UndefValue>(RHS))
3855 return UndefValue::get(ReturnType);
3858 if (IID == Intrinsic::umul_with_overflow ||
3859 IID == Intrinsic::smul_with_overflow) {
3860 // X * 0 -> { 0, false }
3861 if (match(RHS, m_Zero()))
3862 return Constant::getNullValue(ReturnType);
3864 // X * undef -> { 0, false }
3865 if (match(RHS, m_Undef()))
3866 return Constant::getNullValue(ReturnType);
3870 // Perform idempotent optimizations
3871 if (!IsIdempotent(IID))
3875 if (NumOperands == 1)
3876 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*ArgBegin))
3877 if (II->getIntrinsicID() == IID)
3883 template <typename IterTy>
3884 static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd,
3885 const Query &Q, unsigned MaxRecurse) {
3886 Type *Ty = V->getType();
3887 if (PointerType *PTy = dyn_cast<PointerType>(Ty))
3888 Ty = PTy->getElementType();
3889 FunctionType *FTy = cast<FunctionType>(Ty);
3891 // call undef -> undef
3892 if (isa<UndefValue>(V))
3893 return UndefValue::get(FTy->getReturnType());
3895 Function *F = dyn_cast<Function>(V);
3899 if (F->isIntrinsic())
3900 if (Value *Ret = SimplifyIntrinsic(F, ArgBegin, ArgEnd, Q, MaxRecurse))
3903 if (!canConstantFoldCallTo(F))
3906 SmallVector<Constant *, 4> ConstantArgs;
3907 ConstantArgs.reserve(ArgEnd - ArgBegin);
3908 for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) {
3909 Constant *C = dyn_cast<Constant>(*I);
3912 ConstantArgs.push_back(C);
3915 return ConstantFoldCall(F, ConstantArgs, Q.TLI);
3918 Value *llvm::SimplifyCall(Value *V, User::op_iterator ArgBegin,
3919 User::op_iterator ArgEnd, const DataLayout &DL,
3920 const TargetLibraryInfo *TLI, const DominatorTree *DT,
3921 AssumptionCache *AC, const Instruction *CxtI) {
3922 return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(DL, TLI, DT, AC, CxtI),
3926 Value *llvm::SimplifyCall(Value *V, ArrayRef<Value *> Args,
3927 const DataLayout &DL, const TargetLibraryInfo *TLI,
3928 const DominatorTree *DT, AssumptionCache *AC,
3929 const Instruction *CxtI) {
3930 return ::SimplifyCall(V, Args.begin(), Args.end(),
3931 Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3934 /// See if we can compute a simplified version of this instruction.
3935 /// If not, this returns null.
3936 Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout &DL,
3937 const TargetLibraryInfo *TLI,
3938 const DominatorTree *DT, AssumptionCache *AC) {
3941 switch (I->getOpcode()) {
3943 Result = ConstantFoldInstruction(I, DL, TLI);
3945 case Instruction::FAdd:
3946 Result = SimplifyFAddInst(I->getOperand(0), I->getOperand(1),
3947 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3949 case Instruction::Add:
3950 Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1),
3951 cast<BinaryOperator>(I)->hasNoSignedWrap(),
3952 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
3955 case Instruction::FSub:
3956 Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1),
3957 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3959 case Instruction::Sub:
3960 Result = SimplifySubInst(I->getOperand(0), I->getOperand(1),
3961 cast<BinaryOperator>(I)->hasNoSignedWrap(),
3962 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
3965 case Instruction::FMul:
3966 Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1),
3967 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3969 case Instruction::Mul:
3971 SimplifyMulInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
3973 case Instruction::SDiv:
3974 Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3977 case Instruction::UDiv:
3978 Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3981 case Instruction::FDiv:
3982 Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1),
3983 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3985 case Instruction::SRem:
3986 Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3989 case Instruction::URem:
3990 Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3993 case Instruction::FRem:
3994 Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1),
3995 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3997 case Instruction::Shl:
3998 Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1),
3999 cast<BinaryOperator>(I)->hasNoSignedWrap(),
4000 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
4003 case Instruction::LShr:
4004 Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1),
4005 cast<BinaryOperator>(I)->isExact(), DL, TLI, DT,
4008 case Instruction::AShr:
4009 Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1),
4010 cast<BinaryOperator>(I)->isExact(), DL, TLI, DT,
4013 case Instruction::And:
4015 SimplifyAndInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
4017 case Instruction::Or:
4019 SimplifyOrInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
4021 case Instruction::Xor:
4023 SimplifyXorInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
4025 case Instruction::ICmp:
4027 SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), I->getOperand(0),
4028 I->getOperand(1), DL, TLI, DT, AC, I);
4030 case Instruction::FCmp:
4031 Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
4032 I->getOperand(0), I->getOperand(1),
4033 I->getFastMathFlags(), DL, TLI, DT, AC, I);
4035 case Instruction::Select:
4036 Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
4037 I->getOperand(2), DL, TLI, DT, AC, I);
4039 case Instruction::GetElementPtr: {
4040 SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
4041 Result = SimplifyGEPInst(Ops, DL, TLI, DT, AC, I);
4044 case Instruction::InsertValue: {
4045 InsertValueInst *IV = cast<InsertValueInst>(I);
4046 Result = SimplifyInsertValueInst(IV->getAggregateOperand(),
4047 IV->getInsertedValueOperand(),
4048 IV->getIndices(), DL, TLI, DT, AC, I);
4051 case Instruction::ExtractValue: {
4052 auto *EVI = cast<ExtractValueInst>(I);
4053 Result = SimplifyExtractValueInst(EVI->getAggregateOperand(),
4054 EVI->getIndices(), DL, TLI, DT, AC, I);
4057 case Instruction::ExtractElement: {
4058 auto *EEI = cast<ExtractElementInst>(I);
4059 Result = SimplifyExtractElementInst(
4060 EEI->getVectorOperand(), EEI->getIndexOperand(), DL, TLI, DT, AC, I);
4063 case Instruction::PHI:
4064 Result = SimplifyPHINode(cast<PHINode>(I), Query(DL, TLI, DT, AC, I));
4066 case Instruction::Call: {
4067 CallSite CS(cast<CallInst>(I));
4068 Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(), DL,
4072 case Instruction::Trunc:
4074 SimplifyTruncInst(I->getOperand(0), I->getType(), DL, TLI, DT, AC, I);
4078 // In general, it is possible for computeKnownBits to determine all bits in a
4079 // value even when the operands are not all constants.
4080 if (!Result && I->getType()->isIntegerTy()) {
4081 unsigned BitWidth = I->getType()->getScalarSizeInBits();
4082 APInt KnownZero(BitWidth, 0);
4083 APInt KnownOne(BitWidth, 0);
4084 computeKnownBits(I, KnownZero, KnownOne, DL, /*Depth*/0, AC, I, DT);
4085 if ((KnownZero | KnownOne).isAllOnesValue())
4086 Result = ConstantInt::get(I->getContext(), KnownOne);
4089 /// If called on unreachable code, the above logic may report that the
4090 /// instruction simplified to itself. Make life easier for users by
4091 /// detecting that case here, returning a safe value instead.
4092 return Result == I ? UndefValue::get(I->getType()) : Result;
4095 /// \brief Implementation of recursive simplification through an instructions
4098 /// This is the common implementation of the recursive simplification routines.
4099 /// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
4100 /// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
4101 /// instructions to process and attempt to simplify it using
4102 /// InstructionSimplify.
4104 /// This routine returns 'true' only when *it* simplifies something. The passed
4105 /// in simplified value does not count toward this.
4106 static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
4107 const TargetLibraryInfo *TLI,
4108 const DominatorTree *DT,
4109 AssumptionCache *AC) {
4110 bool Simplified = false;
4111 SmallSetVector<Instruction *, 8> Worklist;
4112 const DataLayout &DL = I->getModule()->getDataLayout();
4114 // If we have an explicit value to collapse to, do that round of the
4115 // simplification loop by hand initially.
4117 for (User *U : I->users())
4119 Worklist.insert(cast<Instruction>(U));
4121 // Replace the instruction with its simplified value.
4122 I->replaceAllUsesWith(SimpleV);
4124 // Gracefully handle edge cases where the instruction is not wired into any
4127 I->eraseFromParent();
4132 // Note that we must test the size on each iteration, the worklist can grow.
4133 for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
4136 // See if this instruction simplifies.
4137 SimpleV = SimplifyInstruction(I, DL, TLI, DT, AC);
4143 // Stash away all the uses of the old instruction so we can check them for
4144 // recursive simplifications after a RAUW. This is cheaper than checking all
4145 // uses of To on the recursive step in most cases.
4146 for (User *U : I->users())
4147 Worklist.insert(cast<Instruction>(U));
4149 // Replace the instruction with its simplified value.
4150 I->replaceAllUsesWith(SimpleV);
4152 // Gracefully handle edge cases where the instruction is not wired into any
4155 I->eraseFromParent();
4160 bool llvm::recursivelySimplifyInstruction(Instruction *I,
4161 const TargetLibraryInfo *TLI,
4162 const DominatorTree *DT,
4163 AssumptionCache *AC) {
4164 return replaceAndRecursivelySimplifyImpl(I, nullptr, TLI, DT, AC);
4167 bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
4168 const TargetLibraryInfo *TLI,
4169 const DominatorTree *DT,
4170 AssumptionCache *AC) {
4171 assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!");
4172 assert(SimpleV && "Must provide a simplified value.");
4173 return replaceAndRecursivelySimplifyImpl(I, SimpleV, TLI, DT, AC);