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(),
2104 if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
2105 return AI->getParent() && AI->getParent()->getParent() &&
2106 AI->isStaticAlloca();
2107 if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
2108 return (GV->hasLocalLinkage() ||
2109 GV->hasHiddenVisibility() ||
2110 GV->hasProtectedVisibility() ||
2111 GV->hasUnnamedAddr()) &&
2112 !GV->isThreadLocal();
2113 if (const Argument *A = dyn_cast<Argument>(V))
2114 return A->hasByValAttr();
2119 if ((IsNAC(LHSUObjs) && IsAllocDisjoint(RHSUObjs)) ||
2120 (IsNAC(RHSUObjs) && IsAllocDisjoint(LHSUObjs)))
2121 return ConstantInt::get(GetCompareTy(LHS),
2122 !CmpInst::isTrueWhenEqual(Pred));
2129 /// Given operands for an ICmpInst, see if we can fold the result.
2130 /// If not, this returns null.
2131 static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2132 const Query &Q, unsigned MaxRecurse) {
2133 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
2134 assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
2136 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
2137 if (Constant *CRHS = dyn_cast<Constant>(RHS))
2138 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
2140 // If we have a constant, make sure it is on the RHS.
2141 std::swap(LHS, RHS);
2142 Pred = CmpInst::getSwappedPredicate(Pred);
2145 Type *ITy = GetCompareTy(LHS); // The return type.
2146 Type *OpTy = LHS->getType(); // The operand type.
2148 // icmp X, X -> true/false
2149 // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false
2150 // because X could be 0.
2151 if (LHS == RHS || isa<UndefValue>(RHS))
2152 return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
2154 // Special case logic when the operands have i1 type.
2155 if (OpTy->getScalarType()->isIntegerTy(1)) {
2158 case ICmpInst::ICMP_EQ:
2160 if (match(RHS, m_One()))
2163 case ICmpInst::ICMP_NE:
2165 if (match(RHS, m_Zero()))
2168 case ICmpInst::ICMP_UGT:
2170 if (match(RHS, m_Zero()))
2173 case ICmpInst::ICMP_UGE:
2175 if (match(RHS, m_One()))
2177 if (isImpliedCondition(RHS, LHS, Q.DL))
2178 return getTrue(ITy);
2180 case ICmpInst::ICMP_SGE:
2181 /// For signed comparison, the values for an i1 are 0 and -1
2182 /// respectively. This maps into a truth table of:
2183 /// LHS | RHS | LHS >=s RHS | LHS implies RHS
2184 /// 0 | 0 | 1 (0 >= 0) | 1
2185 /// 0 | 1 | 1 (0 >= -1) | 1
2186 /// 1 | 0 | 0 (-1 >= 0) | 0
2187 /// 1 | 1 | 1 (-1 >= -1) | 1
2188 if (isImpliedCondition(LHS, RHS, Q.DL))
2189 return getTrue(ITy);
2191 case ICmpInst::ICMP_SLT:
2193 if (match(RHS, m_Zero()))
2196 case ICmpInst::ICMP_SLE:
2198 if (match(RHS, m_One()))
2201 case ICmpInst::ICMP_ULE:
2202 if (isImpliedCondition(LHS, RHS, Q.DL))
2203 return getTrue(ITy);
2208 // If we are comparing with zero then try hard since this is a common case.
2209 if (match(RHS, m_Zero())) {
2210 bool LHSKnownNonNegative, LHSKnownNegative;
2212 default: llvm_unreachable("Unknown ICmp predicate!");
2213 case ICmpInst::ICMP_ULT:
2214 return getFalse(ITy);
2215 case ICmpInst::ICMP_UGE:
2216 return getTrue(ITy);
2217 case ICmpInst::ICMP_EQ:
2218 case ICmpInst::ICMP_ULE:
2219 if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2220 return getFalse(ITy);
2222 case ICmpInst::ICMP_NE:
2223 case ICmpInst::ICMP_UGT:
2224 if (isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2225 return getTrue(ITy);
2227 case ICmpInst::ICMP_SLT:
2228 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2230 if (LHSKnownNegative)
2231 return getTrue(ITy);
2232 if (LHSKnownNonNegative)
2233 return getFalse(ITy);
2235 case ICmpInst::ICMP_SLE:
2236 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2238 if (LHSKnownNegative)
2239 return getTrue(ITy);
2240 if (LHSKnownNonNegative &&
2241 isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2242 return getFalse(ITy);
2244 case ICmpInst::ICMP_SGE:
2245 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2247 if (LHSKnownNegative)
2248 return getFalse(ITy);
2249 if (LHSKnownNonNegative)
2250 return getTrue(ITy);
2252 case ICmpInst::ICMP_SGT:
2253 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.DL, 0, Q.AC,
2255 if (LHSKnownNegative)
2256 return getFalse(ITy);
2257 if (LHSKnownNonNegative &&
2258 isKnownNonZero(LHS, Q.DL, 0, Q.AC, Q.CxtI, Q.DT))
2259 return getTrue(ITy);
2264 // See if we are doing a comparison with a constant integer.
2265 if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2266 // Rule out tautological comparisons (eg., ult 0 or uge 0).
2267 ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue());
2268 if (RHS_CR.isEmptySet())
2269 return ConstantInt::getFalse(CI->getContext());
2270 if (RHS_CR.isFullSet())
2271 return ConstantInt::getTrue(CI->getContext());
2273 // Many binary operators with constant RHS have easy to compute constant
2274 // range. Use them to check whether the comparison is a tautology.
2275 unsigned Width = CI->getBitWidth();
2276 APInt Lower = APInt(Width, 0);
2277 APInt Upper = APInt(Width, 0);
2279 if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) {
2280 // 'urem x, CI2' produces [0, CI2).
2281 Upper = CI2->getValue();
2282 } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) {
2283 // 'srem x, CI2' produces (-|CI2|, |CI2|).
2284 Upper = CI2->getValue().abs();
2285 Lower = (-Upper) + 1;
2286 } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) {
2287 // 'udiv CI2, x' produces [0, CI2].
2288 Upper = CI2->getValue() + 1;
2289 } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) {
2290 // 'udiv x, CI2' produces [0, UINT_MAX / CI2].
2291 APInt NegOne = APInt::getAllOnesValue(Width);
2293 Upper = NegOne.udiv(CI2->getValue()) + 1;
2294 } else if (match(LHS, m_SDiv(m_ConstantInt(CI2), m_Value()))) {
2295 if (CI2->isMinSignedValue()) {
2296 // 'sdiv INT_MIN, x' produces [INT_MIN, INT_MIN / -2].
2297 Lower = CI2->getValue();
2298 Upper = Lower.lshr(1) + 1;
2300 // 'sdiv CI2, x' produces [-|CI2|, |CI2|].
2301 Upper = CI2->getValue().abs() + 1;
2302 Lower = (-Upper) + 1;
2304 } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) {
2305 APInt IntMin = APInt::getSignedMinValue(Width);
2306 APInt IntMax = APInt::getSignedMaxValue(Width);
2307 APInt Val = CI2->getValue();
2308 if (Val.isAllOnesValue()) {
2309 // 'sdiv x, -1' produces [INT_MIN + 1, INT_MAX]
2310 // where CI2 != -1 and CI2 != 0 and CI2 != 1
2313 } else if (Val.countLeadingZeros() < Width - 1) {
2314 // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2]
2315 // where CI2 != -1 and CI2 != 0 and CI2 != 1
2316 Lower = IntMin.sdiv(Val);
2317 Upper = IntMax.sdiv(Val);
2318 if (Lower.sgt(Upper))
2319 std::swap(Lower, Upper);
2321 assert(Upper != Lower && "Upper part of range has wrapped!");
2323 } else if (match(LHS, m_NUWShl(m_ConstantInt(CI2), m_Value()))) {
2324 // 'shl nuw CI2, x' produces [CI2, CI2 << CLZ(CI2)]
2325 Lower = CI2->getValue();
2326 Upper = Lower.shl(Lower.countLeadingZeros()) + 1;
2327 } else if (match(LHS, m_NSWShl(m_ConstantInt(CI2), m_Value()))) {
2328 if (CI2->isNegative()) {
2329 // 'shl nsw CI2, x' produces [CI2 << CLO(CI2)-1, CI2]
2330 unsigned ShiftAmount = CI2->getValue().countLeadingOnes() - 1;
2331 Lower = CI2->getValue().shl(ShiftAmount);
2332 Upper = CI2->getValue() + 1;
2334 // 'shl nsw CI2, x' produces [CI2, CI2 << CLZ(CI2)-1]
2335 unsigned ShiftAmount = CI2->getValue().countLeadingZeros() - 1;
2336 Lower = CI2->getValue();
2337 Upper = CI2->getValue().shl(ShiftAmount) + 1;
2339 } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {
2340 // 'lshr x, CI2' produces [0, UINT_MAX >> CI2].
2341 APInt NegOne = APInt::getAllOnesValue(Width);
2342 if (CI2->getValue().ult(Width))
2343 Upper = NegOne.lshr(CI2->getValue()) + 1;
2344 } else if (match(LHS, m_LShr(m_ConstantInt(CI2), m_Value()))) {
2345 // 'lshr CI2, x' produces [CI2 >> (Width-1), CI2].
2346 unsigned ShiftAmount = Width - 1;
2347 if (!CI2->isZero() && cast<BinaryOperator>(LHS)->isExact())
2348 ShiftAmount = CI2->getValue().countTrailingZeros();
2349 Lower = CI2->getValue().lshr(ShiftAmount);
2350 Upper = CI2->getValue() + 1;
2351 } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) {
2352 // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2].
2353 APInt IntMin = APInt::getSignedMinValue(Width);
2354 APInt IntMax = APInt::getSignedMaxValue(Width);
2355 if (CI2->getValue().ult(Width)) {
2356 Lower = IntMin.ashr(CI2->getValue());
2357 Upper = IntMax.ashr(CI2->getValue()) + 1;
2359 } else if (match(LHS, m_AShr(m_ConstantInt(CI2), m_Value()))) {
2360 unsigned ShiftAmount = Width - 1;
2361 if (!CI2->isZero() && cast<BinaryOperator>(LHS)->isExact())
2362 ShiftAmount = CI2->getValue().countTrailingZeros();
2363 if (CI2->isNegative()) {
2364 // 'ashr CI2, x' produces [CI2, CI2 >> (Width-1)]
2365 Lower = CI2->getValue();
2366 Upper = CI2->getValue().ashr(ShiftAmount) + 1;
2368 // 'ashr CI2, x' produces [CI2 >> (Width-1), CI2]
2369 Lower = CI2->getValue().ashr(ShiftAmount);
2370 Upper = CI2->getValue() + 1;
2372 } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) {
2373 // 'or x, CI2' produces [CI2, UINT_MAX].
2374 Lower = CI2->getValue();
2375 } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) {
2376 // 'and x, CI2' produces [0, CI2].
2377 Upper = CI2->getValue() + 1;
2378 } else if (match(LHS, m_NUWAdd(m_Value(), m_ConstantInt(CI2)))) {
2379 // 'add nuw x, CI2' produces [CI2, UINT_MAX].
2380 Lower = CI2->getValue();
2383 ConstantRange LHS_CR = Lower != Upper ? ConstantRange(Lower, Upper)
2384 : ConstantRange(Width, true);
2386 if (auto *I = dyn_cast<Instruction>(LHS))
2387 if (auto *Ranges = I->getMetadata(LLVMContext::MD_range))
2388 LHS_CR = LHS_CR.intersectWith(getConstantRangeFromMetadata(*Ranges));
2390 if (!LHS_CR.isFullSet()) {
2391 if (RHS_CR.contains(LHS_CR))
2392 return ConstantInt::getTrue(RHS->getContext());
2393 if (RHS_CR.inverse().contains(LHS_CR))
2394 return ConstantInt::getFalse(RHS->getContext());
2398 // If both operands have range metadata, use the metadata
2399 // to simplify the comparison.
2400 if (isa<Instruction>(RHS) && isa<Instruction>(LHS)) {
2401 auto RHS_Instr = dyn_cast<Instruction>(RHS);
2402 auto LHS_Instr = dyn_cast<Instruction>(LHS);
2404 if (RHS_Instr->getMetadata(LLVMContext::MD_range) &&
2405 LHS_Instr->getMetadata(LLVMContext::MD_range)) {
2406 auto RHS_CR = getConstantRangeFromMetadata(
2407 *RHS_Instr->getMetadata(LLVMContext::MD_range));
2408 auto LHS_CR = getConstantRangeFromMetadata(
2409 *LHS_Instr->getMetadata(LLVMContext::MD_range));
2411 auto Satisfied_CR = ConstantRange::makeSatisfyingICmpRegion(Pred, RHS_CR);
2412 if (Satisfied_CR.contains(LHS_CR))
2413 return ConstantInt::getTrue(RHS->getContext());
2415 auto InversedSatisfied_CR = ConstantRange::makeSatisfyingICmpRegion(
2416 CmpInst::getInversePredicate(Pred), RHS_CR);
2417 if (InversedSatisfied_CR.contains(LHS_CR))
2418 return ConstantInt::getFalse(RHS->getContext());
2422 // Compare of cast, for example (zext X) != 0 -> X != 0
2423 if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
2424 Instruction *LI = cast<CastInst>(LHS);
2425 Value *SrcOp = LI->getOperand(0);
2426 Type *SrcTy = SrcOp->getType();
2427 Type *DstTy = LI->getType();
2429 // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
2430 // if the integer type is the same size as the pointer type.
2431 if (MaxRecurse && isa<PtrToIntInst>(LI) &&
2432 Q.DL.getTypeSizeInBits(SrcTy) == DstTy->getPrimitiveSizeInBits()) {
2433 if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
2434 // Transfer the cast to the constant.
2435 if (Value *V = SimplifyICmpInst(Pred, SrcOp,
2436 ConstantExpr::getIntToPtr(RHSC, SrcTy),
2439 } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) {
2440 if (RI->getOperand(0)->getType() == SrcTy)
2441 // Compare without the cast.
2442 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
2448 if (isa<ZExtInst>(LHS)) {
2449 // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
2451 if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) {
2452 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
2453 // Compare X and Y. Note that signed predicates become unsigned.
2454 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
2455 SrcOp, RI->getOperand(0), Q,
2459 // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
2460 // too. If not, then try to deduce the result of the comparison.
2461 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2462 // Compute the constant that would happen if we truncated to SrcTy then
2463 // reextended to DstTy.
2464 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
2465 Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy);
2467 // If the re-extended constant didn't change then this is effectively
2468 // also a case of comparing two zero-extended values.
2469 if (RExt == CI && MaxRecurse)
2470 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
2471 SrcOp, Trunc, Q, MaxRecurse-1))
2474 // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
2475 // there. Use this to work out the result of the comparison.
2478 default: llvm_unreachable("Unknown ICmp predicate!");
2480 case ICmpInst::ICMP_EQ:
2481 case ICmpInst::ICMP_UGT:
2482 case ICmpInst::ICMP_UGE:
2483 return ConstantInt::getFalse(CI->getContext());
2485 case ICmpInst::ICMP_NE:
2486 case ICmpInst::ICMP_ULT:
2487 case ICmpInst::ICMP_ULE:
2488 return ConstantInt::getTrue(CI->getContext());
2490 // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
2491 // is non-negative then LHS <s RHS.
2492 case ICmpInst::ICMP_SGT:
2493 case ICmpInst::ICMP_SGE:
2494 return CI->getValue().isNegative() ?
2495 ConstantInt::getTrue(CI->getContext()) :
2496 ConstantInt::getFalse(CI->getContext());
2498 case ICmpInst::ICMP_SLT:
2499 case ICmpInst::ICMP_SLE:
2500 return CI->getValue().isNegative() ?
2501 ConstantInt::getFalse(CI->getContext()) :
2502 ConstantInt::getTrue(CI->getContext());
2508 if (isa<SExtInst>(LHS)) {
2509 // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
2511 if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) {
2512 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
2513 // Compare X and Y. Note that the predicate does not change.
2514 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
2518 // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
2519 // too. If not, then try to deduce the result of the comparison.
2520 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2521 // Compute the constant that would happen if we truncated to SrcTy then
2522 // reextended to DstTy.
2523 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
2524 Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy);
2526 // If the re-extended constant didn't change then this is effectively
2527 // also a case of comparing two sign-extended values.
2528 if (RExt == CI && MaxRecurse)
2529 if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1))
2532 // Otherwise the upper bits of LHS are all equal, while RHS has varying
2533 // bits there. Use this to work out the result of the comparison.
2536 default: llvm_unreachable("Unknown ICmp predicate!");
2537 case ICmpInst::ICMP_EQ:
2538 return ConstantInt::getFalse(CI->getContext());
2539 case ICmpInst::ICMP_NE:
2540 return ConstantInt::getTrue(CI->getContext());
2542 // If RHS is non-negative then LHS <s RHS. If RHS is negative then
2544 case ICmpInst::ICMP_SGT:
2545 case ICmpInst::ICMP_SGE:
2546 return CI->getValue().isNegative() ?
2547 ConstantInt::getTrue(CI->getContext()) :
2548 ConstantInt::getFalse(CI->getContext());
2549 case ICmpInst::ICMP_SLT:
2550 case ICmpInst::ICMP_SLE:
2551 return CI->getValue().isNegative() ?
2552 ConstantInt::getFalse(CI->getContext()) :
2553 ConstantInt::getTrue(CI->getContext());
2555 // If LHS is non-negative then LHS <u RHS. If LHS is negative then
2557 case ICmpInst::ICMP_UGT:
2558 case ICmpInst::ICMP_UGE:
2559 // Comparison is true iff the LHS <s 0.
2561 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
2562 Constant::getNullValue(SrcTy),
2566 case ICmpInst::ICMP_ULT:
2567 case ICmpInst::ICMP_ULE:
2568 // Comparison is true iff the LHS >=s 0.
2570 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
2571 Constant::getNullValue(SrcTy),
2581 // icmp eq|ne X, Y -> false|true if X != Y
2582 if ((Pred == ICmpInst::ICMP_EQ || Pred == ICmpInst::ICMP_NE) &&
2583 isKnownNonEqual(LHS, RHS, Q.DL, Q.AC, Q.CxtI, Q.DT)) {
2584 LLVMContext &Ctx = LHS->getType()->getContext();
2585 return Pred == ICmpInst::ICMP_NE ?
2586 ConstantInt::getTrue(Ctx) : ConstantInt::getFalse(Ctx);
2589 // Special logic for binary operators.
2590 BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS);
2591 BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
2592 if (MaxRecurse && (LBO || RBO)) {
2593 // Analyze the case when either LHS or RHS is an add instruction.
2594 Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr;
2595 // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
2596 bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
2597 if (LBO && LBO->getOpcode() == Instruction::Add) {
2598 A = LBO->getOperand(0); B = LBO->getOperand(1);
2599 NoLHSWrapProblem = ICmpInst::isEquality(Pred) ||
2600 (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) ||
2601 (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap());
2603 if (RBO && RBO->getOpcode() == Instruction::Add) {
2604 C = RBO->getOperand(0); D = RBO->getOperand(1);
2605 NoRHSWrapProblem = ICmpInst::isEquality(Pred) ||
2606 (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) ||
2607 (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap());
2610 // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
2611 if ((A == RHS || B == RHS) && NoLHSWrapProblem)
2612 if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A,
2613 Constant::getNullValue(RHS->getType()),
2617 // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
2618 if ((C == LHS || D == LHS) && NoRHSWrapProblem)
2619 if (Value *V = SimplifyICmpInst(Pred,
2620 Constant::getNullValue(LHS->getType()),
2621 C == LHS ? D : C, Q, MaxRecurse-1))
2624 // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
2625 if (A && C && (A == C || A == D || B == C || B == D) &&
2626 NoLHSWrapProblem && NoRHSWrapProblem) {
2627 // Determine Y and Z in the form icmp (X+Y), (X+Z).
2630 // C + B == C + D -> B == D
2633 } else if (A == D) {
2634 // D + B == C + D -> B == C
2637 } else if (B == C) {
2638 // A + C == C + D -> A == D
2643 // A + D == C + D -> A == C
2647 if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))
2652 // icmp pred (or X, Y), X
2653 if (LBO && match(LBO, m_CombineOr(m_Or(m_Value(), m_Specific(RHS)),
2654 m_Or(m_Specific(RHS), m_Value())))) {
2655 if (Pred == ICmpInst::ICMP_ULT)
2656 return getFalse(ITy);
2657 if (Pred == ICmpInst::ICMP_UGE)
2658 return getTrue(ITy);
2660 // icmp pred X, (or X, Y)
2661 if (RBO && match(RBO, m_CombineOr(m_Or(m_Value(), m_Specific(LHS)),
2662 m_Or(m_Specific(LHS), m_Value())))) {
2663 if (Pred == ICmpInst::ICMP_ULE)
2664 return getTrue(ITy);
2665 if (Pred == ICmpInst::ICMP_UGT)
2666 return getFalse(ITy);
2669 // icmp pred (and X, Y), X
2670 if (LBO && match(LBO, m_CombineOr(m_And(m_Value(), m_Specific(RHS)),
2671 m_And(m_Specific(RHS), m_Value())))) {
2672 if (Pred == ICmpInst::ICMP_UGT)
2673 return getFalse(ITy);
2674 if (Pred == ICmpInst::ICMP_ULE)
2675 return getTrue(ITy);
2677 // icmp pred X, (and X, Y)
2678 if (RBO && match(RBO, m_CombineOr(m_And(m_Value(), m_Specific(LHS)),
2679 m_And(m_Specific(LHS), m_Value())))) {
2680 if (Pred == ICmpInst::ICMP_UGE)
2681 return getTrue(ITy);
2682 if (Pred == ICmpInst::ICMP_ULT)
2683 return getFalse(ITy);
2686 // 0 - (zext X) pred C
2687 if (!CmpInst::isUnsigned(Pred) && match(LHS, m_Neg(m_ZExt(m_Value())))) {
2688 if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS)) {
2689 if (RHSC->getValue().isStrictlyPositive()) {
2690 if (Pred == ICmpInst::ICMP_SLT)
2691 return ConstantInt::getTrue(RHSC->getContext());
2692 if (Pred == ICmpInst::ICMP_SGE)
2693 return ConstantInt::getFalse(RHSC->getContext());
2694 if (Pred == ICmpInst::ICMP_EQ)
2695 return ConstantInt::getFalse(RHSC->getContext());
2696 if (Pred == ICmpInst::ICMP_NE)
2697 return ConstantInt::getTrue(RHSC->getContext());
2699 if (RHSC->getValue().isNonNegative()) {
2700 if (Pred == ICmpInst::ICMP_SLE)
2701 return ConstantInt::getTrue(RHSC->getContext());
2702 if (Pred == ICmpInst::ICMP_SGT)
2703 return ConstantInt::getFalse(RHSC->getContext());
2708 // icmp pred (urem X, Y), Y
2709 if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
2710 bool KnownNonNegative, KnownNegative;
2714 case ICmpInst::ICMP_SGT:
2715 case ICmpInst::ICMP_SGE:
2716 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2718 if (!KnownNonNegative)
2721 case ICmpInst::ICMP_EQ:
2722 case ICmpInst::ICMP_UGT:
2723 case ICmpInst::ICMP_UGE:
2724 return getFalse(ITy);
2725 case ICmpInst::ICMP_SLT:
2726 case ICmpInst::ICMP_SLE:
2727 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2729 if (!KnownNonNegative)
2732 case ICmpInst::ICMP_NE:
2733 case ICmpInst::ICMP_ULT:
2734 case ICmpInst::ICMP_ULE:
2735 return getTrue(ITy);
2739 // icmp pred X, (urem Y, X)
2740 if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
2741 bool KnownNonNegative, KnownNegative;
2745 case ICmpInst::ICMP_SGT:
2746 case ICmpInst::ICMP_SGE:
2747 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2749 if (!KnownNonNegative)
2752 case ICmpInst::ICMP_NE:
2753 case ICmpInst::ICMP_UGT:
2754 case ICmpInst::ICMP_UGE:
2755 return getTrue(ITy);
2756 case ICmpInst::ICMP_SLT:
2757 case ICmpInst::ICMP_SLE:
2758 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.DL, 0, Q.AC,
2760 if (!KnownNonNegative)
2763 case ICmpInst::ICMP_EQ:
2764 case ICmpInst::ICMP_ULT:
2765 case ICmpInst::ICMP_ULE:
2766 return getFalse(ITy);
2771 if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) {
2772 // icmp pred (X /u Y), X
2773 if (Pred == ICmpInst::ICMP_UGT)
2774 return getFalse(ITy);
2775 if (Pred == ICmpInst::ICMP_ULE)
2776 return getTrue(ITy);
2783 // where CI2 is a power of 2 and CI isn't
2784 if (auto *CI = dyn_cast<ConstantInt>(RHS)) {
2785 const APInt *CI2Val, *CIVal = &CI->getValue();
2786 if (LBO && match(LBO, m_Shl(m_APInt(CI2Val), m_Value())) &&
2787 CI2Val->isPowerOf2()) {
2788 if (!CIVal->isPowerOf2()) {
2789 // CI2 << X can equal zero in some circumstances,
2790 // this simplification is unsafe if CI is zero.
2792 // We know it is safe if:
2793 // - The shift is nsw, we can't shift out the one bit.
2794 // - The shift is nuw, we can't shift out the one bit.
2797 if (LBO->hasNoSignedWrap() || LBO->hasNoUnsignedWrap() ||
2798 *CI2Val == 1 || !CI->isZero()) {
2799 if (Pred == ICmpInst::ICMP_EQ)
2800 return ConstantInt::getFalse(RHS->getContext());
2801 if (Pred == ICmpInst::ICMP_NE)
2802 return ConstantInt::getTrue(RHS->getContext());
2805 if (CIVal->isSignBit() && *CI2Val == 1) {
2806 if (Pred == ICmpInst::ICMP_UGT)
2807 return ConstantInt::getFalse(RHS->getContext());
2808 if (Pred == ICmpInst::ICMP_ULE)
2809 return ConstantInt::getTrue(RHS->getContext());
2814 if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
2815 LBO->getOperand(1) == RBO->getOperand(1)) {
2816 switch (LBO->getOpcode()) {
2818 case Instruction::UDiv:
2819 case Instruction::LShr:
2820 if (ICmpInst::isSigned(Pred))
2823 case Instruction::SDiv:
2824 case Instruction::AShr:
2825 if (!LBO->isExact() || !RBO->isExact())
2827 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2828 RBO->getOperand(0), Q, MaxRecurse-1))
2831 case Instruction::Shl: {
2832 bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap();
2833 bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap();
2836 if (!NSW && ICmpInst::isSigned(Pred))
2838 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2839 RBO->getOperand(0), Q, MaxRecurse-1))
2846 // Simplify comparisons involving max/min.
2848 CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
2849 CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
2851 // Signed variants on "max(a,b)>=a -> true".
2852 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2853 if (A != RHS) std::swap(A, B); // smax(A, B) pred A.
2854 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2855 // We analyze this as smax(A, B) pred A.
2857 } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
2858 (A == LHS || B == LHS)) {
2859 if (A != LHS) std::swap(A, B); // A pred smax(A, B).
2860 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2861 // We analyze this as smax(A, B) swapped-pred A.
2862 P = CmpInst::getSwappedPredicate(Pred);
2863 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2864 (A == RHS || B == RHS)) {
2865 if (A != RHS) std::swap(A, B); // smin(A, B) pred A.
2866 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2867 // We analyze this as smax(-A, -B) swapped-pred -A.
2868 // Note that we do not need to actually form -A or -B thanks to EqP.
2869 P = CmpInst::getSwappedPredicate(Pred);
2870 } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
2871 (A == LHS || B == LHS)) {
2872 if (A != LHS) std::swap(A, B); // A pred smin(A, B).
2873 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2874 // We analyze this as smax(-A, -B) pred -A.
2875 // Note that we do not need to actually form -A or -B thanks to EqP.
2878 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2879 // Cases correspond to "max(A, B) p A".
2883 case CmpInst::ICMP_EQ:
2884 case CmpInst::ICMP_SLE:
2885 // Equivalent to "A EqP B". This may be the same as the condition tested
2886 // in the max/min; if so, we can just return that.
2887 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2889 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2891 // Otherwise, see if "A EqP B" simplifies.
2893 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2896 case CmpInst::ICMP_NE:
2897 case CmpInst::ICMP_SGT: {
2898 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2899 // Equivalent to "A InvEqP B". This may be the same as the condition
2900 // tested in the max/min; if so, we can just return that.
2901 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2903 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2905 // Otherwise, see if "A InvEqP B" simplifies.
2907 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2911 case CmpInst::ICMP_SGE:
2913 return getTrue(ITy);
2914 case CmpInst::ICMP_SLT:
2916 return getFalse(ITy);
2920 // Unsigned variants on "max(a,b)>=a -> true".
2921 P = CmpInst::BAD_ICMP_PREDICATE;
2922 if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2923 if (A != RHS) std::swap(A, B); // umax(A, B) pred A.
2924 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2925 // We analyze this as umax(A, B) pred A.
2927 } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
2928 (A == LHS || B == LHS)) {
2929 if (A != LHS) std::swap(A, B); // A pred umax(A, B).
2930 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2931 // We analyze this as umax(A, B) swapped-pred A.
2932 P = CmpInst::getSwappedPredicate(Pred);
2933 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
2934 (A == RHS || B == RHS)) {
2935 if (A != RHS) std::swap(A, B); // umin(A, B) pred A.
2936 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2937 // We analyze this as umax(-A, -B) swapped-pred -A.
2938 // Note that we do not need to actually form -A or -B thanks to EqP.
2939 P = CmpInst::getSwappedPredicate(Pred);
2940 } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
2941 (A == LHS || B == LHS)) {
2942 if (A != LHS) std::swap(A, B); // A pred umin(A, B).
2943 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2944 // We analyze this as umax(-A, -B) pred -A.
2945 // Note that we do not need to actually form -A or -B thanks to EqP.
2948 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2949 // Cases correspond to "max(A, B) p A".
2953 case CmpInst::ICMP_EQ:
2954 case CmpInst::ICMP_ULE:
2955 // Equivalent to "A EqP B". This may be the same as the condition tested
2956 // in the max/min; if so, we can just return that.
2957 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2959 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2961 // Otherwise, see if "A EqP B" simplifies.
2963 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2966 case CmpInst::ICMP_NE:
2967 case CmpInst::ICMP_UGT: {
2968 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2969 // Equivalent to "A InvEqP B". This may be the same as the condition
2970 // tested in the max/min; if so, we can just return that.
2971 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2973 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2975 // Otherwise, see if "A InvEqP B" simplifies.
2977 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2981 case CmpInst::ICMP_UGE:
2983 return getTrue(ITy);
2984 case CmpInst::ICMP_ULT:
2986 return getFalse(ITy);
2990 // Variants on "max(x,y) >= min(x,z)".
2992 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) &&
2993 match(RHS, m_SMin(m_Value(C), m_Value(D))) &&
2994 (A == C || A == D || B == C || B == D)) {
2995 // max(x, ?) pred min(x, ?).
2996 if (Pred == CmpInst::ICMP_SGE)
2998 return getTrue(ITy);
2999 if (Pred == CmpInst::ICMP_SLT)
3001 return getFalse(ITy);
3002 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
3003 match(RHS, m_SMax(m_Value(C), m_Value(D))) &&
3004 (A == C || A == D || B == C || B == D)) {
3005 // min(x, ?) pred max(x, ?).
3006 if (Pred == CmpInst::ICMP_SLE)
3008 return getTrue(ITy);
3009 if (Pred == CmpInst::ICMP_SGT)
3011 return getFalse(ITy);
3012 } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) &&
3013 match(RHS, m_UMin(m_Value(C), m_Value(D))) &&
3014 (A == C || A == D || B == C || B == D)) {
3015 // max(x, ?) pred min(x, ?).
3016 if (Pred == CmpInst::ICMP_UGE)
3018 return getTrue(ITy);
3019 if (Pred == CmpInst::ICMP_ULT)
3021 return getFalse(ITy);
3022 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
3023 match(RHS, m_UMax(m_Value(C), m_Value(D))) &&
3024 (A == C || A == D || B == C || B == D)) {
3025 // min(x, ?) pred max(x, ?).
3026 if (Pred == CmpInst::ICMP_ULE)
3028 return getTrue(ITy);
3029 if (Pred == CmpInst::ICMP_UGT)
3031 return getFalse(ITy);
3034 // Simplify comparisons of related pointers using a powerful, recursive
3035 // GEP-walk when we have target data available..
3036 if (LHS->getType()->isPointerTy())
3037 if (Constant *C = computePointerICmp(Q.DL, Q.TLI, Pred, LHS, RHS))
3040 if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) {
3041 if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) {
3042 if (GLHS->getPointerOperand() == GRHS->getPointerOperand() &&
3043 GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() &&
3044 (ICmpInst::isEquality(Pred) ||
3045 (GLHS->isInBounds() && GRHS->isInBounds() &&
3046 Pred == ICmpInst::getSignedPredicate(Pred)))) {
3047 // The bases are equal and the indices are constant. Build a constant
3048 // expression GEP with the same indices and a null base pointer to see
3049 // what constant folding can make out of it.
3050 Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType());
3051 SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end());
3052 Constant *NewLHS = ConstantExpr::getGetElementPtr(
3053 GLHS->getSourceElementType(), Null, IndicesLHS);
3055 SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end());
3056 Constant *NewRHS = ConstantExpr::getGetElementPtr(
3057 GLHS->getSourceElementType(), Null, IndicesRHS);
3058 return ConstantExpr::getICmp(Pred, NewLHS, NewRHS);
3063 // If a bit is known to be zero for A and known to be one for B,
3064 // then A and B cannot be equal.
3065 if (ICmpInst::isEquality(Pred)) {
3066 if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
3067 uint32_t BitWidth = CI->getBitWidth();
3068 APInt LHSKnownZero(BitWidth, 0);
3069 APInt LHSKnownOne(BitWidth, 0);
3070 computeKnownBits(LHS, LHSKnownZero, LHSKnownOne, Q.DL, /*Depth=*/0, Q.AC,
3072 const APInt &RHSVal = CI->getValue();
3073 if (((LHSKnownZero & RHSVal) != 0) || ((LHSKnownOne & ~RHSVal) != 0))
3074 return Pred == ICmpInst::ICMP_EQ
3075 ? ConstantInt::getFalse(CI->getContext())
3076 : ConstantInt::getTrue(CI->getContext());
3080 // If the comparison is with the result of a select instruction, check whether
3081 // comparing with either branch of the select always yields the same value.
3082 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
3083 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
3086 // If the comparison is with the result of a phi instruction, check whether
3087 // doing the compare with each incoming phi value yields a common result.
3088 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3089 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
3095 Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3096 const DataLayout &DL,
3097 const TargetLibraryInfo *TLI,
3098 const DominatorTree *DT, AssumptionCache *AC,
3099 const Instruction *CxtI) {
3100 return ::SimplifyICmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
3104 /// Given operands for an FCmpInst, see if we can fold the result.
3105 /// If not, this returns null.
3106 static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3107 FastMathFlags FMF, const Query &Q,
3108 unsigned MaxRecurse) {
3109 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
3110 assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
3112 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
3113 if (Constant *CRHS = dyn_cast<Constant>(RHS))
3114 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.DL, Q.TLI);
3116 // If we have a constant, make sure it is on the RHS.
3117 std::swap(LHS, RHS);
3118 Pred = CmpInst::getSwappedPredicate(Pred);
3121 // Fold trivial predicates.
3122 if (Pred == FCmpInst::FCMP_FALSE)
3123 return ConstantInt::get(GetCompareTy(LHS), 0);
3124 if (Pred == FCmpInst::FCMP_TRUE)
3125 return ConstantInt::get(GetCompareTy(LHS), 1);
3127 // UNO/ORD predicates can be trivially folded if NaNs are ignored.
3129 if (Pred == FCmpInst::FCMP_UNO)
3130 return ConstantInt::get(GetCompareTy(LHS), 0);
3131 if (Pred == FCmpInst::FCMP_ORD)
3132 return ConstantInt::get(GetCompareTy(LHS), 1);
3135 // fcmp pred x, undef and fcmp pred undef, x
3136 // fold to true if unordered, false if ordered
3137 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS)) {
3138 // Choosing NaN for the undef will always make unordered comparison succeed
3139 // and ordered comparison fail.
3140 return ConstantInt::get(GetCompareTy(LHS), CmpInst::isUnordered(Pred));
3143 // fcmp x,x -> true/false. Not all compares are foldable.
3145 if (CmpInst::isTrueWhenEqual(Pred))
3146 return ConstantInt::get(GetCompareTy(LHS), 1);
3147 if (CmpInst::isFalseWhenEqual(Pred))
3148 return ConstantInt::get(GetCompareTy(LHS), 0);
3151 // Handle fcmp with constant RHS
3152 if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHS)) {
3153 // If the constant is a nan, see if we can fold the comparison based on it.
3154 if (CFP->getValueAPF().isNaN()) {
3155 if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo"
3156 return ConstantInt::getFalse(CFP->getContext());
3157 assert(FCmpInst::isUnordered(Pred) &&
3158 "Comparison must be either ordered or unordered!");
3159 // True if unordered.
3160 return ConstantInt::getTrue(CFP->getContext());
3162 // Check whether the constant is an infinity.
3163 if (CFP->getValueAPF().isInfinity()) {
3164 if (CFP->getValueAPF().isNegative()) {
3166 case FCmpInst::FCMP_OLT:
3167 // No value is ordered and less than negative infinity.
3168 return ConstantInt::getFalse(CFP->getContext());
3169 case FCmpInst::FCMP_UGE:
3170 // All values are unordered with or at least negative infinity.
3171 return ConstantInt::getTrue(CFP->getContext());
3177 case FCmpInst::FCMP_OGT:
3178 // No value is ordered and greater than infinity.
3179 return ConstantInt::getFalse(CFP->getContext());
3180 case FCmpInst::FCMP_ULE:
3181 // All values are unordered with and at most infinity.
3182 return ConstantInt::getTrue(CFP->getContext());
3188 if (CFP->getValueAPF().isZero()) {
3190 case FCmpInst::FCMP_UGE:
3191 if (CannotBeOrderedLessThanZero(LHS))
3192 return ConstantInt::getTrue(CFP->getContext());
3194 case FCmpInst::FCMP_OLT:
3196 if (CannotBeOrderedLessThanZero(LHS))
3197 return ConstantInt::getFalse(CFP->getContext());
3205 // If the comparison is with the result of a select instruction, check whether
3206 // comparing with either branch of the select always yields the same value.
3207 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
3208 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
3211 // If the comparison is with the result of a phi instruction, check whether
3212 // doing the compare with each incoming phi value yields a common result.
3213 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3214 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
3220 Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3221 FastMathFlags FMF, const DataLayout &DL,
3222 const TargetLibraryInfo *TLI,
3223 const DominatorTree *DT, AssumptionCache *AC,
3224 const Instruction *CxtI) {
3225 return ::SimplifyFCmpInst(Predicate, LHS, RHS, FMF,
3226 Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3229 /// See if V simplifies when its operand Op is replaced with RepOp.
3230 static const Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
3232 unsigned MaxRecurse) {
3233 // Trivial replacement.
3237 auto *I = dyn_cast<Instruction>(V);
3241 // If this is a binary operator, try to simplify it with the replaced op.
3242 if (auto *B = dyn_cast<BinaryOperator>(I)) {
3244 // %cmp = icmp eq i32 %x, 2147483647
3245 // %add = add nsw i32 %x, 1
3246 // %sel = select i1 %cmp, i32 -2147483648, i32 %add
3248 // We can't replace %sel with %add unless we strip away the flags.
3249 if (isa<OverflowingBinaryOperator>(B))
3250 if (B->hasNoSignedWrap() || B->hasNoUnsignedWrap())
3252 if (isa<PossiblyExactOperator>(B))
3257 if (B->getOperand(0) == Op)
3258 return SimplifyBinOp(B->getOpcode(), RepOp, B->getOperand(1), Q,
3260 if (B->getOperand(1) == Op)
3261 return SimplifyBinOp(B->getOpcode(), B->getOperand(0), RepOp, Q,
3266 // Same for CmpInsts.
3267 if (CmpInst *C = dyn_cast<CmpInst>(I)) {
3269 if (C->getOperand(0) == Op)
3270 return SimplifyCmpInst(C->getPredicate(), RepOp, C->getOperand(1), Q,
3272 if (C->getOperand(1) == Op)
3273 return SimplifyCmpInst(C->getPredicate(), C->getOperand(0), RepOp, Q,
3278 // TODO: We could hand off more cases to instsimplify here.
3280 // If all operands are constant after substituting Op for RepOp then we can
3281 // constant fold the instruction.
3282 if (Constant *CRepOp = dyn_cast<Constant>(RepOp)) {
3283 // Build a list of all constant operands.
3284 SmallVector<Constant *, 8> ConstOps;
3285 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
3286 if (I->getOperand(i) == Op)
3287 ConstOps.push_back(CRepOp);
3288 else if (Constant *COp = dyn_cast<Constant>(I->getOperand(i)))
3289 ConstOps.push_back(COp);
3294 // All operands were constants, fold it.
3295 if (ConstOps.size() == I->getNumOperands()) {
3296 if (CmpInst *C = dyn_cast<CmpInst>(I))
3297 return ConstantFoldCompareInstOperands(C->getPredicate(), ConstOps[0],
3298 ConstOps[1], Q.DL, Q.TLI);
3300 if (LoadInst *LI = dyn_cast<LoadInst>(I))
3301 if (!LI->isVolatile())
3302 return ConstantFoldLoadFromConstPtr(ConstOps[0], Q.DL);
3304 return ConstantFoldInstOperands(I->getOpcode(), I->getType(), ConstOps,
3312 /// Given operands for a SelectInst, see if we can fold the result.
3313 /// If not, this returns null.
3314 static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
3315 Value *FalseVal, const Query &Q,
3316 unsigned MaxRecurse) {
3317 // select true, X, Y -> X
3318 // select false, X, Y -> Y
3319 if (Constant *CB = dyn_cast<Constant>(CondVal)) {
3320 if (CB->isAllOnesValue())
3322 if (CB->isNullValue())
3326 // select C, X, X -> X
3327 if (TrueVal == FalseVal)
3330 if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
3331 if (isa<Constant>(TrueVal))
3335 if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
3337 if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
3340 if (const auto *ICI = dyn_cast<ICmpInst>(CondVal)) {
3341 unsigned BitWidth = Q.DL.getTypeSizeInBits(TrueVal->getType());
3342 ICmpInst::Predicate Pred = ICI->getPredicate();
3343 Value *CmpLHS = ICI->getOperand(0);
3344 Value *CmpRHS = ICI->getOperand(1);
3345 APInt MinSignedValue = APInt::getSignBit(BitWidth);
3349 bool IsBitTest = false;
3350 if (ICmpInst::isEquality(Pred) &&
3351 match(CmpLHS, m_And(m_Value(X), m_APInt(Y))) &&
3352 match(CmpRHS, m_Zero())) {
3354 TrueWhenUnset = Pred == ICmpInst::ICMP_EQ;
3355 } else if (Pred == ICmpInst::ICMP_SLT && match(CmpRHS, m_Zero())) {
3357 Y = &MinSignedValue;
3359 TrueWhenUnset = false;
3360 } else if (Pred == ICmpInst::ICMP_SGT && match(CmpRHS, m_AllOnes())) {
3362 Y = &MinSignedValue;
3364 TrueWhenUnset = true;
3368 // (X & Y) == 0 ? X & ~Y : X --> X
3369 // (X & Y) != 0 ? X & ~Y : X --> X & ~Y
3370 if (FalseVal == X && match(TrueVal, m_And(m_Specific(X), m_APInt(C))) &&
3372 return TrueWhenUnset ? FalseVal : TrueVal;
3373 // (X & Y) == 0 ? X : X & ~Y --> X & ~Y
3374 // (X & Y) != 0 ? X : X & ~Y --> X
3375 if (TrueVal == X && match(FalseVal, m_And(m_Specific(X), m_APInt(C))) &&
3377 return TrueWhenUnset ? FalseVal : TrueVal;
3379 if (Y->isPowerOf2()) {
3380 // (X & Y) == 0 ? X | Y : X --> X | Y
3381 // (X & Y) != 0 ? X | Y : X --> X
3382 if (FalseVal == X && match(TrueVal, m_Or(m_Specific(X), m_APInt(C))) &&
3384 return TrueWhenUnset ? TrueVal : FalseVal;
3385 // (X & Y) == 0 ? X : X | Y --> X
3386 // (X & Y) != 0 ? X : X | Y --> X | Y
3387 if (TrueVal == X && match(FalseVal, m_Or(m_Specific(X), m_APInt(C))) &&
3389 return TrueWhenUnset ? TrueVal : FalseVal;
3392 if (ICI->hasOneUse()) {
3394 if (match(CmpRHS, m_APInt(C))) {
3395 // X < MIN ? T : F --> F
3396 if (Pred == ICmpInst::ICMP_SLT && C->isMinSignedValue())
3398 // X < MIN ? T : F --> F
3399 if (Pred == ICmpInst::ICMP_ULT && C->isMinValue())
3401 // X > MAX ? T : F --> F
3402 if (Pred == ICmpInst::ICMP_SGT && C->isMaxSignedValue())
3404 // X > MAX ? T : F --> F
3405 if (Pred == ICmpInst::ICMP_UGT && C->isMaxValue())
3410 // If we have an equality comparison then we know the value in one of the
3411 // arms of the select. See if substituting this value into the arm and
3412 // simplifying the result yields the same value as the other arm.
3413 if (Pred == ICmpInst::ICMP_EQ) {
3414 if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3416 SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3419 if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3421 SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3424 } else if (Pred == ICmpInst::ICMP_NE) {
3425 if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3427 SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3430 if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q, MaxRecurse) ==
3432 SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, Q, MaxRecurse) ==
3441 Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
3442 const DataLayout &DL,
3443 const TargetLibraryInfo *TLI,
3444 const DominatorTree *DT, AssumptionCache *AC,
3445 const Instruction *CxtI) {
3446 return ::SimplifySelectInst(Cond, TrueVal, FalseVal,
3447 Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3450 /// Given operands for an GetElementPtrInst, see if we can fold the result.
3451 /// If not, this returns null.
3452 static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops,
3453 const Query &Q, unsigned) {
3454 // The type of the GEP pointer operand.
3456 cast<PointerType>(Ops[0]->getType()->getScalarType())->getAddressSpace();
3458 // getelementptr P -> P.
3459 if (Ops.size() == 1)
3462 // Compute the (pointer) type returned by the GEP instruction.
3463 Type *LastType = GetElementPtrInst::getIndexedType(SrcTy, Ops.slice(1));
3464 Type *GEPTy = PointerType::get(LastType, AS);
3465 if (VectorType *VT = dyn_cast<VectorType>(Ops[0]->getType()))
3466 GEPTy = VectorType::get(GEPTy, VT->getNumElements());
3468 if (isa<UndefValue>(Ops[0]))
3469 return UndefValue::get(GEPTy);
3471 if (Ops.size() == 2) {
3472 // getelementptr P, 0 -> P.
3473 if (match(Ops[1], m_Zero()))
3477 if (Ty->isSized()) {
3480 uint64_t TyAllocSize = Q.DL.getTypeAllocSize(Ty);
3481 // getelementptr P, N -> P if P points to a type of zero size.
3482 if (TyAllocSize == 0)
3485 // The following transforms are only safe if the ptrtoint cast
3486 // doesn't truncate the pointers.
3487 if (Ops[1]->getType()->getScalarSizeInBits() ==
3488 Q.DL.getPointerSizeInBits(AS)) {
3489 auto PtrToIntOrZero = [GEPTy](Value *P) -> Value * {
3490 if (match(P, m_Zero()))
3491 return Constant::getNullValue(GEPTy);
3493 if (match(P, m_PtrToInt(m_Value(Temp))))
3494 if (Temp->getType() == GEPTy)
3499 // getelementptr V, (sub P, V) -> P if P points to a type of size 1.
3500 if (TyAllocSize == 1 &&
3501 match(Ops[1], m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0])))))
3502 if (Value *R = PtrToIntOrZero(P))
3505 // getelementptr V, (ashr (sub P, V), C) -> Q
3506 // if P points to a type of size 1 << C.
3508 m_AShr(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
3509 m_ConstantInt(C))) &&
3510 TyAllocSize == 1ULL << C)
3511 if (Value *R = PtrToIntOrZero(P))
3514 // getelementptr V, (sdiv (sub P, V), C) -> Q
3515 // if P points to a type of size C.
3517 m_SDiv(m_Sub(m_Value(P), m_PtrToInt(m_Specific(Ops[0]))),
3518 m_SpecificInt(TyAllocSize))))
3519 if (Value *R = PtrToIntOrZero(P))
3525 // Check to see if this is constant foldable.
3526 for (unsigned i = 0, e = Ops.size(); i != e; ++i)
3527 if (!isa<Constant>(Ops[i]))
3530 return ConstantExpr::getGetElementPtr(SrcTy, cast<Constant>(Ops[0]),
3534 Value *llvm::SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout &DL,
3535 const TargetLibraryInfo *TLI,
3536 const DominatorTree *DT, AssumptionCache *AC,
3537 const Instruction *CxtI) {
3538 return ::SimplifyGEPInst(
3539 cast<PointerType>(Ops[0]->getType()->getScalarType())->getElementType(),
3540 Ops, Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3543 /// Given operands for an InsertValueInst, see if we can fold the result.
3544 /// If not, this returns null.
3545 static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
3546 ArrayRef<unsigned> Idxs, const Query &Q,
3548 if (Constant *CAgg = dyn_cast<Constant>(Agg))
3549 if (Constant *CVal = dyn_cast<Constant>(Val))
3550 return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs);
3552 // insertvalue x, undef, n -> x
3553 if (match(Val, m_Undef()))
3556 // insertvalue x, (extractvalue y, n), n
3557 if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val))
3558 if (EV->getAggregateOperand()->getType() == Agg->getType() &&
3559 EV->getIndices() == Idxs) {
3560 // insertvalue undef, (extractvalue y, n), n -> y
3561 if (match(Agg, m_Undef()))
3562 return EV->getAggregateOperand();
3564 // insertvalue y, (extractvalue y, n), n -> y
3565 if (Agg == EV->getAggregateOperand())
3572 Value *llvm::SimplifyInsertValueInst(
3573 Value *Agg, Value *Val, ArrayRef<unsigned> Idxs, const DataLayout &DL,
3574 const TargetLibraryInfo *TLI, const DominatorTree *DT, AssumptionCache *AC,
3575 const Instruction *CxtI) {
3576 return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query(DL, TLI, DT, AC, CxtI),
3580 /// Given operands for an ExtractValueInst, see if we can fold the result.
3581 /// If not, this returns null.
3582 static Value *SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
3583 const Query &, unsigned) {
3584 if (auto *CAgg = dyn_cast<Constant>(Agg))
3585 return ConstantFoldExtractValueInstruction(CAgg, Idxs);
3587 // extractvalue x, (insertvalue y, elt, n), n -> elt
3588 unsigned NumIdxs = Idxs.size();
3589 for (auto *IVI = dyn_cast<InsertValueInst>(Agg); IVI != nullptr;
3590 IVI = dyn_cast<InsertValueInst>(IVI->getAggregateOperand())) {
3591 ArrayRef<unsigned> InsertValueIdxs = IVI->getIndices();
3592 unsigned NumInsertValueIdxs = InsertValueIdxs.size();
3593 unsigned NumCommonIdxs = std::min(NumInsertValueIdxs, NumIdxs);
3594 if (InsertValueIdxs.slice(0, NumCommonIdxs) ==
3595 Idxs.slice(0, NumCommonIdxs)) {
3596 if (NumIdxs == NumInsertValueIdxs)
3597 return IVI->getInsertedValueOperand();
3605 Value *llvm::SimplifyExtractValueInst(Value *Agg, ArrayRef<unsigned> Idxs,
3606 const DataLayout &DL,
3607 const TargetLibraryInfo *TLI,
3608 const DominatorTree *DT,
3609 AssumptionCache *AC,
3610 const Instruction *CxtI) {
3611 return ::SimplifyExtractValueInst(Agg, Idxs, Query(DL, TLI, DT, AC, CxtI),
3615 /// Given operands for an ExtractElementInst, see if we can fold the result.
3616 /// If not, this returns null.
3617 static Value *SimplifyExtractElementInst(Value *Vec, Value *Idx, const Query &,
3619 if (auto *CVec = dyn_cast<Constant>(Vec)) {
3620 if (auto *CIdx = dyn_cast<Constant>(Idx))
3621 return ConstantFoldExtractElementInstruction(CVec, CIdx);
3623 // The index is not relevant if our vector is a splat.
3624 if (auto *Splat = CVec->getSplatValue())
3627 if (isa<UndefValue>(Vec))
3628 return UndefValue::get(Vec->getType()->getVectorElementType());
3631 // If extracting a specified index from the vector, see if we can recursively
3632 // find a previously computed scalar that was inserted into the vector.
3633 if (auto *IdxC = dyn_cast<ConstantInt>(Idx))
3634 if (Value *Elt = findScalarElement(Vec, IdxC->getZExtValue()))
3640 Value *llvm::SimplifyExtractElementInst(
3641 Value *Vec, Value *Idx, const DataLayout &DL, const TargetLibraryInfo *TLI,
3642 const DominatorTree *DT, AssumptionCache *AC, const Instruction *CxtI) {
3643 return ::SimplifyExtractElementInst(Vec, Idx, Query(DL, TLI, DT, AC, CxtI),
3647 /// See if we can fold the given phi. If not, returns null.
3648 static Value *SimplifyPHINode(PHINode *PN, const Query &Q) {
3649 // If all of the PHI's incoming values are the same then replace the PHI node
3650 // with the common value.
3651 Value *CommonValue = nullptr;
3652 bool HasUndefInput = false;
3653 for (Value *Incoming : PN->incoming_values()) {
3654 // If the incoming value is the phi node itself, it can safely be skipped.
3655 if (Incoming == PN) continue;
3656 if (isa<UndefValue>(Incoming)) {
3657 // Remember that we saw an undef value, but otherwise ignore them.
3658 HasUndefInput = true;
3661 if (CommonValue && Incoming != CommonValue)
3662 return nullptr; // Not the same, bail out.
3663 CommonValue = Incoming;
3666 // If CommonValue is null then all of the incoming values were either undef or
3667 // equal to the phi node itself.
3669 return UndefValue::get(PN->getType());
3671 // If we have a PHI node like phi(X, undef, X), where X is defined by some
3672 // instruction, we cannot return X as the result of the PHI node unless it
3673 // dominates the PHI block.
3675 return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : nullptr;
3680 static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
3681 if (Constant *C = dyn_cast<Constant>(Op))
3682 return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.DL, Q.TLI);
3687 Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout &DL,
3688 const TargetLibraryInfo *TLI,
3689 const DominatorTree *DT, AssumptionCache *AC,
3690 const Instruction *CxtI) {
3691 return ::SimplifyTruncInst(Op, Ty, Query(DL, TLI, DT, AC, CxtI),
3695 //=== Helper functions for higher up the class hierarchy.
3697 /// Given operands for a BinaryOperator, see if we can fold the result.
3698 /// If not, this returns null.
3699 static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3700 const Query &Q, unsigned MaxRecurse) {
3702 case Instruction::Add:
3703 return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
3705 case Instruction::FAdd:
3706 return SimplifyFAddInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3708 case Instruction::Sub:
3709 return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
3711 case Instruction::FSub:
3712 return SimplifyFSubInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3714 case Instruction::Mul: return SimplifyMulInst (LHS, RHS, Q, MaxRecurse);
3715 case Instruction::FMul:
3716 return SimplifyFMulInst (LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3717 case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse);
3718 case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse);
3719 case Instruction::FDiv:
3720 return SimplifyFDivInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3721 case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse);
3722 case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse);
3723 case Instruction::FRem:
3724 return SimplifyFRemInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3725 case Instruction::Shl:
3726 return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
3728 case Instruction::LShr:
3729 return SimplifyLShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
3730 case Instruction::AShr:
3731 return SimplifyAShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
3732 case Instruction::And: return SimplifyAndInst(LHS, RHS, Q, MaxRecurse);
3733 case Instruction::Or: return SimplifyOrInst (LHS, RHS, Q, MaxRecurse);
3734 case Instruction::Xor: return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
3736 if (Constant *CLHS = dyn_cast<Constant>(LHS))
3737 if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
3738 Constant *COps[] = {CLHS, CRHS};
3739 return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.DL,
3743 // If the operation is associative, try some generic simplifications.
3744 if (Instruction::isAssociative(Opcode))
3745 if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse))
3748 // If the operation is with the result of a select instruction check whether
3749 // operating on either branch of the select always yields the same value.
3750 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
3751 if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse))
3754 // If the operation is with the result of a phi instruction, check whether
3755 // operating on all incoming values of the phi always yields the same value.
3756 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
3757 if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
3764 /// Given operands for a BinaryOperator, see if we can fold the result.
3765 /// If not, this returns null.
3766 /// In contrast to SimplifyBinOp, try to use FastMathFlag when folding the
3767 /// result. In case we don't need FastMathFlags, simply fall to SimplifyBinOp.
3768 static Value *SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3769 const FastMathFlags &FMF, const Query &Q,
3770 unsigned MaxRecurse) {
3772 case Instruction::FAdd:
3773 return SimplifyFAddInst(LHS, RHS, FMF, Q, MaxRecurse);
3774 case Instruction::FSub:
3775 return SimplifyFSubInst(LHS, RHS, FMF, Q, MaxRecurse);
3776 case Instruction::FMul:
3777 return SimplifyFMulInst(LHS, RHS, FMF, Q, MaxRecurse);
3779 return SimplifyBinOp(Opcode, LHS, RHS, Q, MaxRecurse);
3783 Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3784 const DataLayout &DL, const TargetLibraryInfo *TLI,
3785 const DominatorTree *DT, AssumptionCache *AC,
3786 const Instruction *CxtI) {
3787 return ::SimplifyBinOp(Opcode, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
3791 Value *llvm::SimplifyFPBinOp(unsigned Opcode, Value *LHS, Value *RHS,
3792 const FastMathFlags &FMF, const DataLayout &DL,
3793 const TargetLibraryInfo *TLI,
3794 const DominatorTree *DT, AssumptionCache *AC,
3795 const Instruction *CxtI) {
3796 return ::SimplifyFPBinOp(Opcode, LHS, RHS, FMF, Query(DL, TLI, DT, AC, CxtI),
3800 /// Given operands for a CmpInst, see if we can fold the result.
3801 static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3802 const Query &Q, unsigned MaxRecurse) {
3803 if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
3804 return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
3805 return SimplifyFCmpInst(Predicate, LHS, RHS, FastMathFlags(), Q, MaxRecurse);
3808 Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
3809 const DataLayout &DL, const TargetLibraryInfo *TLI,
3810 const DominatorTree *DT, AssumptionCache *AC,
3811 const Instruction *CxtI) {
3812 return ::SimplifyCmpInst(Predicate, LHS, RHS, Query(DL, TLI, DT, AC, CxtI),
3816 static bool IsIdempotent(Intrinsic::ID ID) {
3818 default: return false;
3820 // Unary idempotent: f(f(x)) = f(x)
3821 case Intrinsic::fabs:
3822 case Intrinsic::floor:
3823 case Intrinsic::ceil:
3824 case Intrinsic::trunc:
3825 case Intrinsic::rint:
3826 case Intrinsic::nearbyint:
3827 case Intrinsic::round:
3832 template <typename IterTy>
3833 static Value *SimplifyIntrinsic(Function *F, IterTy ArgBegin, IterTy ArgEnd,
3834 const Query &Q, unsigned MaxRecurse) {
3835 Intrinsic::ID IID = F->getIntrinsicID();
3836 unsigned NumOperands = std::distance(ArgBegin, ArgEnd);
3837 Type *ReturnType = F->getReturnType();
3840 if (NumOperands == 2) {
3841 Value *LHS = *ArgBegin;
3842 Value *RHS = *(ArgBegin + 1);
3843 if (IID == Intrinsic::usub_with_overflow ||
3844 IID == Intrinsic::ssub_with_overflow) {
3845 // X - X -> { 0, false }
3847 return Constant::getNullValue(ReturnType);
3849 // X - undef -> undef
3850 // undef - X -> undef
3851 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS))
3852 return UndefValue::get(ReturnType);
3855 if (IID == Intrinsic::uadd_with_overflow ||
3856 IID == Intrinsic::sadd_with_overflow) {
3857 // X + undef -> undef
3858 if (isa<UndefValue>(RHS))
3859 return UndefValue::get(ReturnType);
3862 if (IID == Intrinsic::umul_with_overflow ||
3863 IID == Intrinsic::smul_with_overflow) {
3864 // X * 0 -> { 0, false }
3865 if (match(RHS, m_Zero()))
3866 return Constant::getNullValue(ReturnType);
3868 // X * undef -> { 0, false }
3869 if (match(RHS, m_Undef()))
3870 return Constant::getNullValue(ReturnType);
3874 // Perform idempotent optimizations
3875 if (!IsIdempotent(IID))
3879 if (NumOperands == 1)
3880 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(*ArgBegin))
3881 if (II->getIntrinsicID() == IID)
3887 template <typename IterTy>
3888 static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd,
3889 const Query &Q, unsigned MaxRecurse) {
3890 Type *Ty = V->getType();
3891 if (PointerType *PTy = dyn_cast<PointerType>(Ty))
3892 Ty = PTy->getElementType();
3893 FunctionType *FTy = cast<FunctionType>(Ty);
3895 // call undef -> undef
3896 if (isa<UndefValue>(V))
3897 return UndefValue::get(FTy->getReturnType());
3899 Function *F = dyn_cast<Function>(V);
3903 if (F->isIntrinsic())
3904 if (Value *Ret = SimplifyIntrinsic(F, ArgBegin, ArgEnd, Q, MaxRecurse))
3907 if (!canConstantFoldCallTo(F))
3910 SmallVector<Constant *, 4> ConstantArgs;
3911 ConstantArgs.reserve(ArgEnd - ArgBegin);
3912 for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) {
3913 Constant *C = dyn_cast<Constant>(*I);
3916 ConstantArgs.push_back(C);
3919 return ConstantFoldCall(F, ConstantArgs, Q.TLI);
3922 Value *llvm::SimplifyCall(Value *V, User::op_iterator ArgBegin,
3923 User::op_iterator ArgEnd, const DataLayout &DL,
3924 const TargetLibraryInfo *TLI, const DominatorTree *DT,
3925 AssumptionCache *AC, const Instruction *CxtI) {
3926 return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(DL, TLI, DT, AC, CxtI),
3930 Value *llvm::SimplifyCall(Value *V, ArrayRef<Value *> Args,
3931 const DataLayout &DL, const TargetLibraryInfo *TLI,
3932 const DominatorTree *DT, AssumptionCache *AC,
3933 const Instruction *CxtI) {
3934 return ::SimplifyCall(V, Args.begin(), Args.end(),
3935 Query(DL, TLI, DT, AC, CxtI), RecursionLimit);
3938 /// See if we can compute a simplified version of this instruction.
3939 /// If not, this returns null.
3940 Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout &DL,
3941 const TargetLibraryInfo *TLI,
3942 const DominatorTree *DT, AssumptionCache *AC) {
3945 switch (I->getOpcode()) {
3947 Result = ConstantFoldInstruction(I, DL, TLI);
3949 case Instruction::FAdd:
3950 Result = SimplifyFAddInst(I->getOperand(0), I->getOperand(1),
3951 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3953 case Instruction::Add:
3954 Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1),
3955 cast<BinaryOperator>(I)->hasNoSignedWrap(),
3956 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
3959 case Instruction::FSub:
3960 Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1),
3961 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3963 case Instruction::Sub:
3964 Result = SimplifySubInst(I->getOperand(0), I->getOperand(1),
3965 cast<BinaryOperator>(I)->hasNoSignedWrap(),
3966 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
3969 case Instruction::FMul:
3970 Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1),
3971 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3973 case Instruction::Mul:
3975 SimplifyMulInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
3977 case Instruction::SDiv:
3978 Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3981 case Instruction::UDiv:
3982 Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3985 case Instruction::FDiv:
3986 Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1),
3987 I->getFastMathFlags(), DL, TLI, DT, AC, I);
3989 case Instruction::SRem:
3990 Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3993 case Instruction::URem:
3994 Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT,
3997 case Instruction::FRem:
3998 Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1),
3999 I->getFastMathFlags(), DL, TLI, DT, AC, I);
4001 case Instruction::Shl:
4002 Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1),
4003 cast<BinaryOperator>(I)->hasNoSignedWrap(),
4004 cast<BinaryOperator>(I)->hasNoUnsignedWrap(), DL,
4007 case Instruction::LShr:
4008 Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1),
4009 cast<BinaryOperator>(I)->isExact(), DL, TLI, DT,
4012 case Instruction::AShr:
4013 Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1),
4014 cast<BinaryOperator>(I)->isExact(), DL, TLI, DT,
4017 case Instruction::And:
4019 SimplifyAndInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
4021 case Instruction::Or:
4023 SimplifyOrInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
4025 case Instruction::Xor:
4027 SimplifyXorInst(I->getOperand(0), I->getOperand(1), DL, TLI, DT, AC, I);
4029 case Instruction::ICmp:
4031 SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), I->getOperand(0),
4032 I->getOperand(1), DL, TLI, DT, AC, I);
4034 case Instruction::FCmp:
4035 Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
4036 I->getOperand(0), I->getOperand(1),
4037 I->getFastMathFlags(), DL, TLI, DT, AC, I);
4039 case Instruction::Select:
4040 Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
4041 I->getOperand(2), DL, TLI, DT, AC, I);
4043 case Instruction::GetElementPtr: {
4044 SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
4045 Result = SimplifyGEPInst(Ops, DL, TLI, DT, AC, I);
4048 case Instruction::InsertValue: {
4049 InsertValueInst *IV = cast<InsertValueInst>(I);
4050 Result = SimplifyInsertValueInst(IV->getAggregateOperand(),
4051 IV->getInsertedValueOperand(),
4052 IV->getIndices(), DL, TLI, DT, AC, I);
4055 case Instruction::ExtractValue: {
4056 auto *EVI = cast<ExtractValueInst>(I);
4057 Result = SimplifyExtractValueInst(EVI->getAggregateOperand(),
4058 EVI->getIndices(), DL, TLI, DT, AC, I);
4061 case Instruction::ExtractElement: {
4062 auto *EEI = cast<ExtractElementInst>(I);
4063 Result = SimplifyExtractElementInst(
4064 EEI->getVectorOperand(), EEI->getIndexOperand(), DL, TLI, DT, AC, I);
4067 case Instruction::PHI:
4068 Result = SimplifyPHINode(cast<PHINode>(I), Query(DL, TLI, DT, AC, I));
4070 case Instruction::Call: {
4071 CallSite CS(cast<CallInst>(I));
4072 Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(), DL,
4076 case Instruction::Trunc:
4078 SimplifyTruncInst(I->getOperand(0), I->getType(), DL, TLI, DT, AC, I);
4082 // In general, it is possible for computeKnownBits to determine all bits in a
4083 // value even when the operands are not all constants.
4084 if (!Result && I->getType()->isIntegerTy()) {
4085 unsigned BitWidth = I->getType()->getScalarSizeInBits();
4086 APInt KnownZero(BitWidth, 0);
4087 APInt KnownOne(BitWidth, 0);
4088 computeKnownBits(I, KnownZero, KnownOne, DL, /*Depth*/0, AC, I, DT);
4089 if ((KnownZero | KnownOne).isAllOnesValue())
4090 Result = ConstantInt::get(I->getContext(), KnownOne);
4093 /// If called on unreachable code, the above logic may report that the
4094 /// instruction simplified to itself. Make life easier for users by
4095 /// detecting that case here, returning a safe value instead.
4096 return Result == I ? UndefValue::get(I->getType()) : Result;
4099 /// \brief Implementation of recursive simplification through an instructions
4102 /// This is the common implementation of the recursive simplification routines.
4103 /// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
4104 /// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
4105 /// instructions to process and attempt to simplify it using
4106 /// InstructionSimplify.
4108 /// This routine returns 'true' only when *it* simplifies something. The passed
4109 /// in simplified value does not count toward this.
4110 static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
4111 const TargetLibraryInfo *TLI,
4112 const DominatorTree *DT,
4113 AssumptionCache *AC) {
4114 bool Simplified = false;
4115 SmallSetVector<Instruction *, 8> Worklist;
4116 const DataLayout &DL = I->getModule()->getDataLayout();
4118 // If we have an explicit value to collapse to, do that round of the
4119 // simplification loop by hand initially.
4121 for (User *U : I->users())
4123 Worklist.insert(cast<Instruction>(U));
4125 // Replace the instruction with its simplified value.
4126 I->replaceAllUsesWith(SimpleV);
4128 // Gracefully handle edge cases where the instruction is not wired into any
4131 I->eraseFromParent();
4136 // Note that we must test the size on each iteration, the worklist can grow.
4137 for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
4140 // See if this instruction simplifies.
4141 SimpleV = SimplifyInstruction(I, DL, TLI, DT, AC);
4147 // Stash away all the uses of the old instruction so we can check them for
4148 // recursive simplifications after a RAUW. This is cheaper than checking all
4149 // uses of To on the recursive step in most cases.
4150 for (User *U : I->users())
4151 Worklist.insert(cast<Instruction>(U));
4153 // Replace the instruction with its simplified value.
4154 I->replaceAllUsesWith(SimpleV);
4156 // Gracefully handle edge cases where the instruction is not wired into any
4159 I->eraseFromParent();
4164 bool llvm::recursivelySimplifyInstruction(Instruction *I,
4165 const TargetLibraryInfo *TLI,
4166 const DominatorTree *DT,
4167 AssumptionCache *AC) {
4168 return replaceAndRecursivelySimplifyImpl(I, nullptr, TLI, DT, AC);
4171 bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
4172 const TargetLibraryInfo *TLI,
4173 const DominatorTree *DT,
4174 AssumptionCache *AC) {
4175 assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!");
4176 assert(SimpleV && "Must provide a simplified value.");
4177 return replaceAndRecursivelySimplifyImpl(I, SimpleV, TLI, DT, AC);