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 #define DEBUG_TYPE "instsimplify"
21 #include "llvm/Analysis/InstructionSimplify.h"
22 #include "llvm/ADT/SetVector.h"
23 #include "llvm/ADT/Statistic.h"
24 #include "llvm/Analysis/AliasAnalysis.h"
25 #include "llvm/Analysis/ConstantFolding.h"
26 #include "llvm/Analysis/Dominators.h"
27 #include "llvm/Analysis/ValueTracking.h"
28 #include "llvm/IR/DataLayout.h"
29 #include "llvm/IR/GlobalAlias.h"
30 #include "llvm/IR/Operator.h"
31 #include "llvm/Support/ConstantRange.h"
32 #include "llvm/Support/GetElementPtrTypeIterator.h"
33 #include "llvm/Support/PatternMatch.h"
34 #include "llvm/Support/ValueHandle.h"
36 using namespace llvm::PatternMatch;
38 enum { RecursionLimit = 3 };
40 STATISTIC(NumExpand, "Number of expansions");
41 STATISTIC(NumFactor , "Number of factorizations");
42 STATISTIC(NumReassoc, "Number of reassociations");
46 const TargetLibraryInfo *TLI;
47 const DominatorTree *DT;
49 Query(const DataLayout *td, const TargetLibraryInfo *tli,
50 const DominatorTree *dt) : TD(td), TLI(tli), DT(dt) {}
53 static Value *SimplifyAndInst(Value *, Value *, const Query &, unsigned);
54 static Value *SimplifyBinOp(unsigned, Value *, Value *, const Query &,
56 static Value *SimplifyCmpInst(unsigned, Value *, Value *, const Query &,
58 static Value *SimplifyOrInst(Value *, Value *, const Query &, unsigned);
59 static Value *SimplifyXorInst(Value *, Value *, const Query &, unsigned);
60 static Value *SimplifyTruncInst(Value *, Type *, const Query &, unsigned);
62 /// getFalse - For a boolean type, or a vector of boolean type, return false, or
63 /// a vector with every element false, as appropriate for the type.
64 static Constant *getFalse(Type *Ty) {
65 assert(Ty->getScalarType()->isIntegerTy(1) &&
66 "Expected i1 type or a vector of i1!");
67 return Constant::getNullValue(Ty);
70 /// getTrue - For a boolean type, or a vector of boolean type, return true, or
71 /// a vector with every element true, as appropriate for the type.
72 static Constant *getTrue(Type *Ty) {
73 assert(Ty->getScalarType()->isIntegerTy(1) &&
74 "Expected i1 type or a vector of i1!");
75 return Constant::getAllOnesValue(Ty);
78 /// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"?
79 static bool isSameCompare(Value *V, CmpInst::Predicate Pred, Value *LHS,
81 CmpInst *Cmp = dyn_cast<CmpInst>(V);
84 CmpInst::Predicate CPred = Cmp->getPredicate();
85 Value *CLHS = Cmp->getOperand(0), *CRHS = Cmp->getOperand(1);
86 if (CPred == Pred && CLHS == LHS && CRHS == RHS)
88 return CPred == CmpInst::getSwappedPredicate(Pred) && CLHS == RHS &&
92 /// ValueDominatesPHI - Does the given value dominate the specified phi node?
93 static bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) {
94 Instruction *I = dyn_cast<Instruction>(V);
96 // Arguments and constants dominate all instructions.
99 // If we are processing instructions (and/or basic blocks) that have not been
100 // fully added to a function, the parent nodes may still be null. Simply
101 // return the conservative answer in these cases.
102 if (!I->getParent() || !P->getParent() || !I->getParent()->getParent())
105 // If we have a DominatorTree then do a precise test.
107 if (!DT->isReachableFromEntry(P->getParent()))
109 if (!DT->isReachableFromEntry(I->getParent()))
111 return DT->dominates(I, P);
114 // Otherwise, if the instruction is in the entry block, and is not an invoke,
115 // then it obviously dominates all phi nodes.
116 if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() &&
123 /// ExpandBinOp - Simplify "A op (B op' C)" by distributing op over op', turning
124 /// it into "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is
125 /// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS.
126 /// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)".
127 /// Returns the simplified value, or null if no simplification was performed.
128 static Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS,
129 unsigned OpcToExpand, const Query &Q,
130 unsigned MaxRecurse) {
131 Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand;
132 // Recursion is always used, so bail out at once if we already hit the limit.
136 // Check whether the expression has the form "(A op' B) op C".
137 if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS))
138 if (Op0->getOpcode() == OpcodeToExpand) {
139 // It does! Try turning it into "(A op C) op' (B op C)".
140 Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS;
141 // Do "A op C" and "B op C" both simplify?
142 if (Value *L = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse))
143 if (Value *R = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
144 // They do! Return "L op' R" if it simplifies or is already available.
145 // If "L op' R" equals "A op' B" then "L op' R" is just the LHS.
146 if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand)
147 && L == B && R == A)) {
151 // Otherwise return "L op' R" if it simplifies.
152 if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
159 // Check whether the expression has the form "A op (B op' C)".
160 if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS))
161 if (Op1->getOpcode() == OpcodeToExpand) {
162 // It does! Try turning it into "(A op B) op' (A op C)".
163 Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1);
164 // Do "A op B" and "A op C" both simplify?
165 if (Value *L = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse))
166 if (Value *R = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse)) {
167 // They do! Return "L op' R" if it simplifies or is already available.
168 // If "L op' R" equals "B op' C" then "L op' R" is just the RHS.
169 if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand)
170 && L == C && R == B)) {
174 // Otherwise return "L op' R" if it simplifies.
175 if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) {
185 /// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term
186 /// using the operation OpCodeToExtract. For example, when Opcode is Add and
187 /// OpCodeToExtract is Mul then this tries to turn "(A*B)+(A*C)" into "A*(B+C)".
188 /// Returns the simplified value, or null if no simplification was performed.
189 static Value *FactorizeBinOp(unsigned Opcode, Value *LHS, Value *RHS,
190 unsigned OpcToExtract, const Query &Q,
191 unsigned MaxRecurse) {
192 Instruction::BinaryOps OpcodeToExtract = (Instruction::BinaryOps)OpcToExtract;
193 // Recursion is always used, so bail out at once if we already hit the limit.
197 BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
198 BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
200 if (!Op0 || Op0->getOpcode() != OpcodeToExtract ||
201 !Op1 || Op1->getOpcode() != OpcodeToExtract)
204 // The expression has the form "(A op' B) op (C op' D)".
205 Value *A = Op0->getOperand(0), *B = Op0->getOperand(1);
206 Value *C = Op1->getOperand(0), *D = Op1->getOperand(1);
208 // Use left distributivity, i.e. "X op' (Y op Z) = (X op' Y) op (X op' Z)".
209 // Does the instruction have the form "(A op' B) op (A op' D)" or, in the
210 // commutative case, "(A op' B) op (C op' A)"?
211 if (A == C || (Instruction::isCommutative(OpcodeToExtract) && A == D)) {
212 Value *DD = A == C ? D : C;
213 // Form "A op' (B op DD)" if it simplifies completely.
214 // Does "B op DD" simplify?
215 if (Value *V = SimplifyBinOp(Opcode, B, DD, Q, MaxRecurse)) {
216 // It does! Return "A op' V" if it simplifies or is already available.
217 // If V equals B then "A op' V" is just the LHS. If V equals DD then
218 // "A op' V" is just the RHS.
219 if (V == B || V == DD) {
221 return V == B ? LHS : RHS;
223 // Otherwise return "A op' V" if it simplifies.
224 if (Value *W = SimplifyBinOp(OpcodeToExtract, A, V, Q, MaxRecurse)) {
231 // Use right distributivity, i.e. "(X op Y) op' Z = (X op' Z) op (Y op' Z)".
232 // Does the instruction have the form "(A op' B) op (C op' B)" or, in the
233 // commutative case, "(A op' B) op (B op' D)"?
234 if (B == D || (Instruction::isCommutative(OpcodeToExtract) && B == C)) {
235 Value *CC = B == D ? C : D;
236 // Form "(A op CC) op' B" if it simplifies completely..
237 // Does "A op CC" simplify?
238 if (Value *V = SimplifyBinOp(Opcode, A, CC, Q, MaxRecurse)) {
239 // It does! Return "V op' B" if it simplifies or is already available.
240 // If V equals A then "V op' B" is just the LHS. If V equals CC then
241 // "V op' B" is just the RHS.
242 if (V == A || V == CC) {
244 return V == A ? LHS : RHS;
246 // Otherwise return "V op' B" if it simplifies.
247 if (Value *W = SimplifyBinOp(OpcodeToExtract, V, B, Q, MaxRecurse)) {
257 /// SimplifyAssociativeBinOp - Generic simplifications for associative binary
258 /// operations. Returns the simpler value, or null if none was found.
259 static Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS,
260 const Query &Q, unsigned MaxRecurse) {
261 Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc;
262 assert(Instruction::isAssociative(Opcode) && "Not an associative operation!");
264 // Recursion is always used, so bail out at once if we already hit the limit.
268 BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS);
269 BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS);
271 // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely.
272 if (Op0 && Op0->getOpcode() == Opcode) {
273 Value *A = Op0->getOperand(0);
274 Value *B = Op0->getOperand(1);
277 // Does "B op C" simplify?
278 if (Value *V = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) {
279 // It does! Return "A op V" if it simplifies or is already available.
280 // If V equals B then "A op V" is just the LHS.
281 if (V == B) return LHS;
282 // Otherwise return "A op V" if it simplifies.
283 if (Value *W = SimplifyBinOp(Opcode, A, V, Q, MaxRecurse)) {
290 // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely.
291 if (Op1 && Op1->getOpcode() == Opcode) {
293 Value *B = Op1->getOperand(0);
294 Value *C = Op1->getOperand(1);
296 // Does "A op B" simplify?
297 if (Value *V = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse)) {
298 // It does! Return "V op C" if it simplifies or is already available.
299 // If V equals B then "V op C" is just the RHS.
300 if (V == B) return RHS;
301 // Otherwise return "V op C" if it simplifies.
302 if (Value *W = SimplifyBinOp(Opcode, V, C, Q, MaxRecurse)) {
309 // The remaining transforms require commutativity as well as associativity.
310 if (!Instruction::isCommutative(Opcode))
313 // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely.
314 if (Op0 && Op0->getOpcode() == Opcode) {
315 Value *A = Op0->getOperand(0);
316 Value *B = Op0->getOperand(1);
319 // Does "C op A" simplify?
320 if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
321 // It does! Return "V op B" if it simplifies or is already available.
322 // If V equals A then "V op B" is just the LHS.
323 if (V == A) return LHS;
324 // Otherwise return "V op B" if it simplifies.
325 if (Value *W = SimplifyBinOp(Opcode, V, B, Q, MaxRecurse)) {
332 // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely.
333 if (Op1 && Op1->getOpcode() == Opcode) {
335 Value *B = Op1->getOperand(0);
336 Value *C = Op1->getOperand(1);
338 // Does "C op A" simplify?
339 if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) {
340 // It does! Return "B op V" if it simplifies or is already available.
341 // If V equals C then "B op V" is just the RHS.
342 if (V == C) return RHS;
343 // Otherwise return "B op V" if it simplifies.
344 if (Value *W = SimplifyBinOp(Opcode, B, V, Q, MaxRecurse)) {
354 /// ThreadBinOpOverSelect - In the case of a binary operation with a select
355 /// instruction as an operand, try to simplify the binop by seeing whether
356 /// evaluating it on both branches of the select results in the same value.
357 /// Returns the common value if so, otherwise returns null.
358 static Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS,
359 const Query &Q, unsigned MaxRecurse) {
360 // Recursion is always used, so bail out at once if we already hit the limit.
365 if (isa<SelectInst>(LHS)) {
366 SI = cast<SelectInst>(LHS);
368 assert(isa<SelectInst>(RHS) && "No select instruction operand!");
369 SI = cast<SelectInst>(RHS);
372 // Evaluate the BinOp on the true and false branches of the select.
376 TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, Q, MaxRecurse);
377 FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, Q, MaxRecurse);
379 TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), Q, MaxRecurse);
380 FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), Q, MaxRecurse);
383 // If they simplified to the same value, then return the common value.
384 // If they both failed to simplify then return null.
388 // If one branch simplified to undef, return the other one.
389 if (TV && isa<UndefValue>(TV))
391 if (FV && isa<UndefValue>(FV))
394 // If applying the operation did not change the true and false select values,
395 // then the result of the binop is the select itself.
396 if (TV == SI->getTrueValue() && FV == SI->getFalseValue())
399 // If one branch simplified and the other did not, and the simplified
400 // value is equal to the unsimplified one, return the simplified value.
401 // For example, select (cond, X, X & Z) & Z -> X & Z.
402 if ((FV && !TV) || (TV && !FV)) {
403 // Check that the simplified value has the form "X op Y" where "op" is the
404 // same as the original operation.
405 Instruction *Simplified = dyn_cast<Instruction>(FV ? FV : TV);
406 if (Simplified && Simplified->getOpcode() == Opcode) {
407 // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS".
408 // We already know that "op" is the same as for the simplified value. See
409 // if the operands match too. If so, return the simplified value.
410 Value *UnsimplifiedBranch = FV ? SI->getTrueValue() : SI->getFalseValue();
411 Value *UnsimplifiedLHS = SI == LHS ? UnsimplifiedBranch : LHS;
412 Value *UnsimplifiedRHS = SI == LHS ? RHS : UnsimplifiedBranch;
413 if (Simplified->getOperand(0) == UnsimplifiedLHS &&
414 Simplified->getOperand(1) == UnsimplifiedRHS)
416 if (Simplified->isCommutative() &&
417 Simplified->getOperand(1) == UnsimplifiedLHS &&
418 Simplified->getOperand(0) == UnsimplifiedRHS)
426 /// ThreadCmpOverSelect - In the case of a comparison with a select instruction,
427 /// try to simplify the comparison by seeing whether both branches of the select
428 /// result in the same value. Returns the common value if so, otherwise returns
430 static Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS,
431 Value *RHS, const Query &Q,
432 unsigned MaxRecurse) {
433 // Recursion is always used, so bail out at once if we already hit the limit.
437 // Make sure the select is on the LHS.
438 if (!isa<SelectInst>(LHS)) {
440 Pred = CmpInst::getSwappedPredicate(Pred);
442 assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!");
443 SelectInst *SI = cast<SelectInst>(LHS);
444 Value *Cond = SI->getCondition();
445 Value *TV = SI->getTrueValue();
446 Value *FV = SI->getFalseValue();
448 // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it.
449 // Does "cmp TV, RHS" simplify?
450 Value *TCmp = SimplifyCmpInst(Pred, TV, RHS, Q, MaxRecurse);
452 // It not only simplified, it simplified to the select condition. Replace
454 TCmp = getTrue(Cond->getType());
456 // It didn't simplify. However if "cmp TV, RHS" is equal to the select
457 // condition then we can replace it with 'true'. Otherwise give up.
458 if (!isSameCompare(Cond, Pred, TV, RHS))
460 TCmp = getTrue(Cond->getType());
463 // Does "cmp FV, RHS" simplify?
464 Value *FCmp = SimplifyCmpInst(Pred, FV, RHS, Q, MaxRecurse);
466 // It not only simplified, it simplified to the select condition. Replace
468 FCmp = getFalse(Cond->getType());
470 // It didn't simplify. However if "cmp FV, RHS" is equal to the select
471 // condition then we can replace it with 'false'. Otherwise give up.
472 if (!isSameCompare(Cond, Pred, FV, RHS))
474 FCmp = getFalse(Cond->getType());
477 // If both sides simplified to the same value, then use it as the result of
478 // the original comparison.
482 // The remaining cases only make sense if the select condition has the same
483 // type as the result of the comparison, so bail out if this is not so.
484 if (Cond->getType()->isVectorTy() != RHS->getType()->isVectorTy())
486 // If the false value simplified to false, then the result of the compare
487 // is equal to "Cond && TCmp". This also catches the case when the false
488 // value simplified to false and the true value to true, returning "Cond".
489 if (match(FCmp, m_Zero()))
490 if (Value *V = SimplifyAndInst(Cond, TCmp, Q, MaxRecurse))
492 // If the true value simplified to true, then the result of the compare
493 // is equal to "Cond || FCmp".
494 if (match(TCmp, m_One()))
495 if (Value *V = SimplifyOrInst(Cond, FCmp, Q, MaxRecurse))
497 // Finally, if the false value simplified to true and the true value to
498 // false, then the result of the compare is equal to "!Cond".
499 if (match(FCmp, m_One()) && match(TCmp, m_Zero()))
501 SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()),
508 /// ThreadBinOpOverPHI - In the case of a binary operation with an operand that
509 /// is a PHI instruction, try to simplify the binop by seeing whether evaluating
510 /// it on the incoming phi values yields the same result for every value. If so
511 /// returns the common value, otherwise returns null.
512 static Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS,
513 const Query &Q, unsigned MaxRecurse) {
514 // Recursion is always used, so bail out at once if we already hit the limit.
519 if (isa<PHINode>(LHS)) {
520 PI = cast<PHINode>(LHS);
521 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
522 if (!ValueDominatesPHI(RHS, PI, Q.DT))
525 assert(isa<PHINode>(RHS) && "No PHI instruction operand!");
526 PI = cast<PHINode>(RHS);
527 // Bail out if LHS and the phi may be mutually interdependent due to a loop.
528 if (!ValueDominatesPHI(LHS, PI, Q.DT))
532 // Evaluate the BinOp on the incoming phi values.
533 Value *CommonValue = 0;
534 for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) {
535 Value *Incoming = PI->getIncomingValue(i);
536 // If the incoming value is the phi node itself, it can safely be skipped.
537 if (Incoming == PI) continue;
538 Value *V = PI == LHS ?
539 SimplifyBinOp(Opcode, Incoming, RHS, Q, MaxRecurse) :
540 SimplifyBinOp(Opcode, LHS, Incoming, Q, MaxRecurse);
541 // If the operation failed to simplify, or simplified to a different value
542 // to previously, then give up.
543 if (!V || (CommonValue && V != CommonValue))
551 /// ThreadCmpOverPHI - In the case of a comparison with a PHI instruction, try
552 /// try to simplify the comparison by seeing whether comparing with all of the
553 /// incoming phi values yields the same result every time. If so returns the
554 /// common result, otherwise returns null.
555 static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS,
556 const Query &Q, unsigned MaxRecurse) {
557 // Recursion is always used, so bail out at once if we already hit the limit.
561 // Make sure the phi is on the LHS.
562 if (!isa<PHINode>(LHS)) {
564 Pred = CmpInst::getSwappedPredicate(Pred);
566 assert(isa<PHINode>(LHS) && "Not comparing with a phi instruction!");
567 PHINode *PI = cast<PHINode>(LHS);
569 // Bail out if RHS and the phi may be mutually interdependent due to a loop.
570 if (!ValueDominatesPHI(RHS, PI, Q.DT))
573 // Evaluate the BinOp on the incoming phi values.
574 Value *CommonValue = 0;
575 for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) {
576 Value *Incoming = PI->getIncomingValue(i);
577 // If the incoming value is the phi node itself, it can safely be skipped.
578 if (Incoming == PI) continue;
579 Value *V = SimplifyCmpInst(Pred, Incoming, RHS, Q, MaxRecurse);
580 // If the operation failed to simplify, or simplified to a different value
581 // to previously, then give up.
582 if (!V || (CommonValue && V != CommonValue))
590 /// SimplifyAddInst - Given operands for an Add, see if we can
591 /// fold the result. If not, this returns null.
592 static Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
593 const Query &Q, unsigned MaxRecurse) {
594 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
595 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
596 Constant *Ops[] = { CLHS, CRHS };
597 return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), Ops,
601 // Canonicalize the constant to the RHS.
605 // X + undef -> undef
606 if (match(Op1, m_Undef()))
610 if (match(Op1, m_Zero()))
617 if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) ||
618 match(Op0, m_Sub(m_Value(Y), m_Specific(Op1))))
621 // X + ~X -> -1 since ~X = -X-1
622 if (match(Op0, m_Not(m_Specific(Op1))) ||
623 match(Op1, m_Not(m_Specific(Op0))))
624 return Constant::getAllOnesValue(Op0->getType());
627 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
628 if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
631 // Try some generic simplifications for associative operations.
632 if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, Q,
636 // Mul distributes over Add. Try some generic simplifications based on this.
637 if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul,
641 // Threading Add over selects and phi nodes is pointless, so don't bother.
642 // Threading over the select in "A + select(cond, B, C)" means evaluating
643 // "A+B" and "A+C" and seeing if they are equal; but they are equal if and
644 // only if B and C are equal. If B and C are equal then (since we assume
645 // that operands have already been simplified) "select(cond, B, C)" should
646 // have been simplified to the common value of B and C already. Analysing
647 // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly
648 // for threading over phi nodes.
653 Value *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
654 const DataLayout *TD, const TargetLibraryInfo *TLI,
655 const DominatorTree *DT) {
656 return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
660 /// \brief Compute the base pointer and cumulative constant offsets for V.
662 /// This strips all constant offsets off of V, leaving it the base pointer, and
663 /// accumulates the total constant offset applied in the returned constant. It
664 /// returns 0 if V is not a pointer, and returns the constant '0' if there are
665 /// no constant offsets applied.
667 /// This is very similar to GetPointerBaseWithConstantOffset except it doesn't
668 /// follow non-inbounds geps. This allows it to remain usable for icmp ult/etc.
670 static Constant *stripAndComputeConstantOffsets(const DataLayout *TD,
672 assert(V->getType()->isPointerTy());
674 // Without DataLayout, just be conservative for now. Theoretically, more could
675 // be done in this case.
677 return ConstantInt::get(IntegerType::get(V->getContext(), 64), 0);
679 unsigned IntPtrWidth = TD->getPointerSizeInBits();
680 APInt Offset = APInt::getNullValue(IntPtrWidth);
682 // Even though we don't look through PHI nodes, we could be called on an
683 // instruction in an unreachable block, which may be on a cycle.
684 SmallPtrSet<Value *, 4> Visited;
687 if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
688 if (!GEP->isInBounds() || !GEP->accumulateConstantOffset(*TD, Offset))
690 V = GEP->getPointerOperand();
691 } else if (Operator::getOpcode(V) == Instruction::BitCast) {
692 V = cast<Operator>(V)->getOperand(0);
693 } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
694 if (GA->mayBeOverridden())
696 V = GA->getAliasee();
700 assert(V->getType()->isPointerTy() && "Unexpected operand type!");
701 } while (Visited.insert(V));
703 Type *IntPtrTy = TD->getIntPtrType(V->getContext());
704 return ConstantInt::get(IntPtrTy, Offset);
707 /// \brief Compute the constant difference between two pointer values.
708 /// If the difference is not a constant, returns zero.
709 static Constant *computePointerDifference(const DataLayout *TD,
710 Value *LHS, Value *RHS) {
711 Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS);
712 Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS);
714 // If LHS and RHS are not related via constant offsets to the same base
715 // value, there is nothing we can do here.
719 // Otherwise, the difference of LHS - RHS can be computed as:
721 // = (LHSOffset + Base) - (RHSOffset + Base)
722 // = LHSOffset - RHSOffset
723 return ConstantExpr::getSub(LHSOffset, RHSOffset);
726 /// SimplifySubInst - Given operands for a Sub, see if we can
727 /// fold the result. If not, this returns null.
728 static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
729 const Query &Q, unsigned MaxRecurse) {
730 if (Constant *CLHS = dyn_cast<Constant>(Op0))
731 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
732 Constant *Ops[] = { CLHS, CRHS };
733 return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(),
737 // X - undef -> undef
738 // undef - X -> undef
739 if (match(Op0, m_Undef()) || match(Op1, m_Undef()))
740 return UndefValue::get(Op0->getType());
743 if (match(Op1, m_Zero()))
748 return Constant::getNullValue(Op0->getType());
753 if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) ||
754 match(Op0, m_Shl(m_Specific(Op1), m_One())))
757 // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
758 // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
759 Value *Y = 0, *Z = Op1;
760 if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
761 // See if "V === Y - Z" simplifies.
762 if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1))
763 // It does! Now see if "X + V" simplifies.
764 if (Value *W = SimplifyBinOp(Instruction::Add, X, V, Q, MaxRecurse-1)) {
765 // It does, we successfully reassociated!
769 // See if "V === X - Z" simplifies.
770 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
771 // It does! Now see if "Y + V" simplifies.
772 if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, Q, MaxRecurse-1)) {
773 // It does, we successfully reassociated!
779 // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
780 // For example, X - (X + 1) -> -1
782 if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z)
783 // See if "V === X - Y" simplifies.
784 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
785 // It does! Now see if "V - Z" simplifies.
786 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, Q, MaxRecurse-1)) {
787 // It does, we successfully reassociated!
791 // See if "V === X - Z" simplifies.
792 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
793 // It does! Now see if "V - Y" simplifies.
794 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, Q, MaxRecurse-1)) {
795 // It does, we successfully reassociated!
801 // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
802 // For example, X - (X - Y) -> Y.
804 if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y)
805 // See if "V === Z - X" simplifies.
806 if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, Q, MaxRecurse-1))
807 // It does! Now see if "V + Y" simplifies.
808 if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, Q, MaxRecurse-1)) {
809 // It does, we successfully reassociated!
814 // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
815 if (MaxRecurse && match(Op0, m_Trunc(m_Value(X))) &&
816 match(Op1, m_Trunc(m_Value(Y))))
817 if (X->getType() == Y->getType())
818 // See if "V === X - Y" simplifies.
819 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
820 // It does! Now see if "trunc V" simplifies.
821 if (Value *W = SimplifyTruncInst(V, Op0->getType(), Q, MaxRecurse-1))
822 // It does, return the simplified "trunc V".
825 // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
826 if (match(Op0, m_PtrToInt(m_Value(X))) &&
827 match(Op1, m_PtrToInt(m_Value(Y))))
828 if (Constant *Result = computePointerDifference(Q.TD, X, Y))
829 return ConstantExpr::getIntegerCast(Result, Op0->getType(), true);
831 // Mul distributes over Sub. Try some generic simplifications based on this.
832 if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul,
837 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
838 if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
841 // Threading Sub over selects and phi nodes is pointless, so don't bother.
842 // Threading over the select in "A - select(cond, B, C)" means evaluating
843 // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
844 // only if B and C are equal. If B and C are equal then (since we assume
845 // that operands have already been simplified) "select(cond, B, C)" should
846 // have been simplified to the common value of B and C already. Analysing
847 // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
848 // for threading over phi nodes.
853 Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
854 const DataLayout *TD, const TargetLibraryInfo *TLI,
855 const DominatorTree *DT) {
856 return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
860 /// Given operands for an FAdd, see if we can fold the result. If not, this
862 static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
863 const Query &Q, unsigned MaxRecurse) {
864 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
865 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
866 Constant *Ops[] = { CLHS, CRHS };
867 return ConstantFoldInstOperands(Instruction::FAdd, CLHS->getType(),
871 // Canonicalize the constant to the RHS.
876 if (match(Op1, m_NegZero()))
879 // fadd X, 0 ==> X, when we know X is not -0
880 if (match(Op1, m_Zero()) &&
881 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
884 // fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
885 // where nnan and ninf have to occur at least once somewhere in this
888 if (match(Op1, m_FSub(m_AnyZero(), m_Specific(Op0))))
890 else if (match(Op0, m_FSub(m_AnyZero(), m_Specific(Op1))))
893 Instruction *FSub = cast<Instruction>(SubOp);
894 if ((FMF.noNaNs() || FSub->hasNoNaNs()) &&
895 (FMF.noInfs() || FSub->hasNoInfs()))
896 return Constant::getNullValue(Op0->getType());
902 /// Given operands for an FSub, see if we can fold the result. If not, this
904 static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
905 const Query &Q, unsigned MaxRecurse) {
906 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
907 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
908 Constant *Ops[] = { CLHS, CRHS };
909 return ConstantFoldInstOperands(Instruction::FSub, CLHS->getType(),
915 if (match(Op1, m_Zero()))
918 // fsub X, -0 ==> X, when we know X is not -0
919 if (match(Op1, m_NegZero()) &&
920 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
923 // fsub 0, (fsub -0.0, X) ==> X
925 if (match(Op0, m_AnyZero())) {
926 if (match(Op1, m_FSub(m_NegZero(), m_Value(X))))
928 if (FMF.noSignedZeros() && match(Op1, m_FSub(m_AnyZero(), m_Value(X))))
932 // fsub nnan ninf x, x ==> 0.0
933 if (FMF.noNaNs() && FMF.noInfs() && Op0 == Op1)
934 return Constant::getNullValue(Op0->getType());
939 /// Given the operands for an FMul, see if we can fold the result
940 static Value *SimplifyFMulInst(Value *Op0, Value *Op1,
943 unsigned MaxRecurse) {
944 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
945 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
946 Constant *Ops[] = { CLHS, CRHS };
947 return ConstantFoldInstOperands(Instruction::FMul, CLHS->getType(),
951 // Canonicalize the constant to the RHS.
956 if (match(Op1, m_FPOne()))
959 // fmul nnan nsz X, 0 ==> 0
960 if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZero()))
966 /// SimplifyMulInst - Given operands for a Mul, see if we can
967 /// fold the result. If not, this returns null.
968 static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q,
969 unsigned MaxRecurse) {
970 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
971 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
972 Constant *Ops[] = { CLHS, CRHS };
973 return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(),
977 // Canonicalize the constant to the RHS.
982 if (match(Op1, m_Undef()))
983 return Constant::getNullValue(Op0->getType());
986 if (match(Op1, m_Zero()))
990 if (match(Op1, m_One()))
993 // (X / Y) * Y -> X if the division is exact.
995 if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y
996 match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y)
1000 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
1001 if (Value *V = SimplifyAndInst(Op0, Op1, Q, MaxRecurse-1))
1004 // Try some generic simplifications for associative operations.
1005 if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, Q,
1009 // Mul distributes over Add. Try some generic simplifications based on this.
1010 if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add,
1014 // If the operation is with the result of a select instruction, check whether
1015 // operating on either branch of the select always yields the same value.
1016 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1017 if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, Q,
1021 // If the operation is with the result of a phi instruction, check whether
1022 // operating on all incoming values of the phi always yields the same value.
1023 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1024 if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, Q,
1031 Value *llvm::SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1032 const DataLayout *TD, const TargetLibraryInfo *TLI,
1033 const DominatorTree *DT) {
1034 return ::SimplifyFAddInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit);
1037 Value *llvm::SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1038 const DataLayout *TD, const TargetLibraryInfo *TLI,
1039 const DominatorTree *DT) {
1040 return ::SimplifyFSubInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit);
1043 Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1,
1045 const DataLayout *TD,
1046 const TargetLibraryInfo *TLI,
1047 const DominatorTree *DT) {
1048 return ::SimplifyFMulInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit);
1051 Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const DataLayout *TD,
1052 const TargetLibraryInfo *TLI,
1053 const DominatorTree *DT) {
1054 return ::SimplifyMulInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1057 /// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can
1058 /// fold the result. If not, this returns null.
1059 static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
1060 const Query &Q, unsigned MaxRecurse) {
1061 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1062 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1063 Constant *Ops[] = { C0, C1 };
1064 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
1068 bool isSigned = Opcode == Instruction::SDiv;
1070 // X / undef -> undef
1071 if (match(Op1, m_Undef()))
1075 if (match(Op0, m_Undef()))
1076 return Constant::getNullValue(Op0->getType());
1078 // 0 / X -> 0, we don't need to preserve faults!
1079 if (match(Op0, m_Zero()))
1083 if (match(Op1, m_One()))
1086 if (Op0->getType()->isIntegerTy(1))
1087 // It can't be division by zero, hence it must be division by one.
1092 return ConstantInt::get(Op0->getType(), 1);
1094 // (X * Y) / Y -> X if the multiplication does not overflow.
1095 Value *X = 0, *Y = 0;
1096 if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
1097 if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
1098 OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0);
1099 // If the Mul knows it does not overflow, then we are good to go.
1100 if ((isSigned && Mul->hasNoSignedWrap()) ||
1101 (!isSigned && Mul->hasNoUnsignedWrap()))
1103 // If X has the form X = A / Y then X * Y cannot overflow.
1104 if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X))
1105 if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y)
1109 // (X rem Y) / Y -> 0
1110 if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
1111 (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
1112 return Constant::getNullValue(Op0->getType());
1114 // If the operation is with the result of a select instruction, check whether
1115 // operating on either branch of the select always yields the same value.
1116 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1117 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1120 // If the operation is with the result of a phi instruction, check whether
1121 // operating on all incoming values of the phi always yields the same value.
1122 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1123 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1129 /// SimplifySDivInst - Given operands for an SDiv, see if we can
1130 /// fold the result. If not, this returns null.
1131 static Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q,
1132 unsigned MaxRecurse) {
1133 if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse))
1139 Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const DataLayout *TD,
1140 const TargetLibraryInfo *TLI,
1141 const DominatorTree *DT) {
1142 return ::SimplifySDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1145 /// SimplifyUDivInst - Given operands for a UDiv, see if we can
1146 /// fold the result. If not, this returns null.
1147 static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q,
1148 unsigned MaxRecurse) {
1149 if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse))
1155 Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const DataLayout *TD,
1156 const TargetLibraryInfo *TLI,
1157 const DominatorTree *DT) {
1158 return ::SimplifyUDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1161 static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q,
1163 // undef / X -> undef (the undef could be a snan).
1164 if (match(Op0, m_Undef()))
1167 // X / undef -> undef
1168 if (match(Op1, m_Undef()))
1174 Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const DataLayout *TD,
1175 const TargetLibraryInfo *TLI,
1176 const DominatorTree *DT) {
1177 return ::SimplifyFDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1180 /// SimplifyRem - Given operands for an SRem or URem, see if we can
1181 /// fold the result. If not, this returns null.
1182 static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
1183 const Query &Q, unsigned MaxRecurse) {
1184 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1185 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1186 Constant *Ops[] = { C0, C1 };
1187 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
1191 // X % undef -> undef
1192 if (match(Op1, m_Undef()))
1196 if (match(Op0, m_Undef()))
1197 return Constant::getNullValue(Op0->getType());
1199 // 0 % X -> 0, we don't need to preserve faults!
1200 if (match(Op0, m_Zero()))
1203 // X % 0 -> undef, we don't need to preserve faults!
1204 if (match(Op1, m_Zero()))
1205 return UndefValue::get(Op0->getType());
1208 if (match(Op1, m_One()))
1209 return Constant::getNullValue(Op0->getType());
1211 if (Op0->getType()->isIntegerTy(1))
1212 // It can't be remainder by zero, hence it must be remainder by one.
1213 return Constant::getNullValue(Op0->getType());
1217 return Constant::getNullValue(Op0->getType());
1219 // If the operation is with the result of a select instruction, check whether
1220 // operating on either branch of the select always yields the same value.
1221 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1222 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1225 // If the operation is with the result of a phi instruction, check whether
1226 // operating on all incoming values of the phi always yields the same value.
1227 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1228 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1234 /// SimplifySRemInst - Given operands for an SRem, see if we can
1235 /// fold the result. If not, this returns null.
1236 static Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q,
1237 unsigned MaxRecurse) {
1238 if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse))
1244 Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const DataLayout *TD,
1245 const TargetLibraryInfo *TLI,
1246 const DominatorTree *DT) {
1247 return ::SimplifySRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1250 /// SimplifyURemInst - Given operands for a URem, see if we can
1251 /// fold the result. If not, this returns null.
1252 static Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q,
1253 unsigned MaxRecurse) {
1254 if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse))
1260 Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const DataLayout *TD,
1261 const TargetLibraryInfo *TLI,
1262 const DominatorTree *DT) {
1263 return ::SimplifyURemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1266 static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &,
1268 // undef % X -> undef (the undef could be a snan).
1269 if (match(Op0, m_Undef()))
1272 // X % undef -> undef
1273 if (match(Op1, m_Undef()))
1279 Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const DataLayout *TD,
1280 const TargetLibraryInfo *TLI,
1281 const DominatorTree *DT) {
1282 return ::SimplifyFRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1285 /// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can
1286 /// fold the result. If not, this returns null.
1287 static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
1288 const Query &Q, unsigned MaxRecurse) {
1289 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1290 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1291 Constant *Ops[] = { C0, C1 };
1292 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
1296 // 0 shift by X -> 0
1297 if (match(Op0, m_Zero()))
1300 // X shift by 0 -> X
1301 if (match(Op1, m_Zero()))
1304 // X shift by undef -> undef because it may shift by the bitwidth.
1305 if (match(Op1, m_Undef()))
1308 // Shifting by the bitwidth or more is undefined.
1309 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1))
1310 if (CI->getValue().getLimitedValue() >=
1311 Op0->getType()->getScalarSizeInBits())
1312 return UndefValue::get(Op0->getType());
1314 // If the operation is with the result of a select instruction, check whether
1315 // operating on either branch of the select always yields the same value.
1316 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1317 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1320 // If the operation is with the result of a phi instruction, check whether
1321 // operating on all incoming values of the phi always yields the same value.
1322 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1323 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1329 /// SimplifyShlInst - Given operands for an Shl, see if we can
1330 /// fold the result. If not, this returns null.
1331 static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1332 const Query &Q, unsigned MaxRecurse) {
1333 if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse))
1337 if (match(Op0, m_Undef()))
1338 return Constant::getNullValue(Op0->getType());
1340 // (X >> A) << A -> X
1342 if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1)))))
1347 Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1348 const DataLayout *TD, const TargetLibraryInfo *TLI,
1349 const DominatorTree *DT) {
1350 return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
1354 /// SimplifyLShrInst - Given operands for an LShr, see if we can
1355 /// fold the result. If not, this returns null.
1356 static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1357 const Query &Q, unsigned MaxRecurse) {
1358 if (Value *V = SimplifyShift(Instruction::LShr, Op0, Op1, Q, MaxRecurse))
1362 if (match(Op0, m_Undef()))
1363 return Constant::getNullValue(Op0->getType());
1365 // (X << A) >> A -> X
1367 if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
1368 cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap())
1374 Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1375 const DataLayout *TD,
1376 const TargetLibraryInfo *TLI,
1377 const DominatorTree *DT) {
1378 return ::SimplifyLShrInst(Op0, Op1, isExact, Query (TD, TLI, DT),
1382 /// SimplifyAShrInst - Given operands for an AShr, see if we can
1383 /// fold the result. If not, this returns null.
1384 static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1385 const Query &Q, unsigned MaxRecurse) {
1386 if (Value *V = SimplifyShift(Instruction::AShr, Op0, Op1, Q, MaxRecurse))
1389 // all ones >>a X -> all ones
1390 if (match(Op0, m_AllOnes()))
1393 // undef >>a X -> all ones
1394 if (match(Op0, m_Undef()))
1395 return Constant::getAllOnesValue(Op0->getType());
1397 // (X << A) >> A -> X
1399 if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
1400 cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap())
1406 Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1407 const DataLayout *TD,
1408 const TargetLibraryInfo *TLI,
1409 const DominatorTree *DT) {
1410 return ::SimplifyAShrInst(Op0, Op1, isExact, Query (TD, TLI, DT),
1414 /// SimplifyAndInst - Given operands for an And, see if we can
1415 /// fold the result. If not, this returns null.
1416 static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q,
1417 unsigned MaxRecurse) {
1418 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1419 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1420 Constant *Ops[] = { CLHS, CRHS };
1421 return ConstantFoldInstOperands(Instruction::And, CLHS->getType(),
1425 // Canonicalize the constant to the RHS.
1426 std::swap(Op0, Op1);
1430 if (match(Op1, m_Undef()))
1431 return Constant::getNullValue(Op0->getType());
1438 if (match(Op1, m_Zero()))
1442 if (match(Op1, m_AllOnes()))
1445 // A & ~A = ~A & A = 0
1446 if (match(Op0, m_Not(m_Specific(Op1))) ||
1447 match(Op1, m_Not(m_Specific(Op0))))
1448 return Constant::getNullValue(Op0->getType());
1451 Value *A = 0, *B = 0;
1452 if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
1453 (A == Op1 || B == Op1))
1457 if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
1458 (A == Op0 || B == Op0))
1461 // A & (-A) = A if A is a power of two or zero.
1462 if (match(Op0, m_Neg(m_Specific(Op1))) ||
1463 match(Op1, m_Neg(m_Specific(Op0)))) {
1464 if (isKnownToBeAPowerOfTwo(Op0, /*OrZero*/true))
1466 if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/true))
1470 // Try some generic simplifications for associative operations.
1471 if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q,
1475 // And distributes over Or. Try some generic simplifications based on this.
1476 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or,
1480 // And distributes over Xor. Try some generic simplifications based on this.
1481 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor,
1485 // Or distributes over And. Try some generic simplifications based on this.
1486 if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or,
1490 // If the operation is with the result of a select instruction, check whether
1491 // operating on either branch of the select always yields the same value.
1492 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1493 if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, Q,
1497 // If the operation is with the result of a phi instruction, check whether
1498 // operating on all incoming values of the phi always yields the same value.
1499 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1500 if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, Q,
1507 Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const DataLayout *TD,
1508 const TargetLibraryInfo *TLI,
1509 const DominatorTree *DT) {
1510 return ::SimplifyAndInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1513 /// SimplifyOrInst - Given operands for an Or, see if we can
1514 /// fold the result. If not, this returns null.
1515 static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q,
1516 unsigned MaxRecurse) {
1517 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1518 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1519 Constant *Ops[] = { CLHS, CRHS };
1520 return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(),
1524 // Canonicalize the constant to the RHS.
1525 std::swap(Op0, Op1);
1529 if (match(Op1, m_Undef()))
1530 return Constant::getAllOnesValue(Op0->getType());
1537 if (match(Op1, m_Zero()))
1541 if (match(Op1, m_AllOnes()))
1544 // A | ~A = ~A | A = -1
1545 if (match(Op0, m_Not(m_Specific(Op1))) ||
1546 match(Op1, m_Not(m_Specific(Op0))))
1547 return Constant::getAllOnesValue(Op0->getType());
1550 Value *A = 0, *B = 0;
1551 if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
1552 (A == Op1 || B == Op1))
1556 if (match(Op1, m_And(m_Value(A), m_Value(B))) &&
1557 (A == Op0 || B == Op0))
1560 // ~(A & ?) | A = -1
1561 if (match(Op0, m_Not(m_And(m_Value(A), m_Value(B)))) &&
1562 (A == Op1 || B == Op1))
1563 return Constant::getAllOnesValue(Op1->getType());
1565 // A | ~(A & ?) = -1
1566 if (match(Op1, m_Not(m_And(m_Value(A), m_Value(B)))) &&
1567 (A == Op0 || B == Op0))
1568 return Constant::getAllOnesValue(Op0->getType());
1570 // Try some generic simplifications for associative operations.
1571 if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q,
1575 // Or distributes over And. Try some generic simplifications based on this.
1576 if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, Q,
1580 // And distributes over Or. Try some generic simplifications based on this.
1581 if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And,
1585 // If the operation is with the result of a select instruction, check whether
1586 // operating on either branch of the select always yields the same value.
1587 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1588 if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, Q,
1592 // If the operation is with the result of a phi instruction, check whether
1593 // operating on all incoming values of the phi always yields the same value.
1594 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1595 if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse))
1601 Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const DataLayout *TD,
1602 const TargetLibraryInfo *TLI,
1603 const DominatorTree *DT) {
1604 return ::SimplifyOrInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1607 /// SimplifyXorInst - Given operands for a Xor, see if we can
1608 /// fold the result. If not, this returns null.
1609 static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q,
1610 unsigned MaxRecurse) {
1611 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1612 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1613 Constant *Ops[] = { CLHS, CRHS };
1614 return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(),
1618 // Canonicalize the constant to the RHS.
1619 std::swap(Op0, Op1);
1622 // A ^ undef -> undef
1623 if (match(Op1, m_Undef()))
1627 if (match(Op1, m_Zero()))
1632 return Constant::getNullValue(Op0->getType());
1634 // A ^ ~A = ~A ^ A = -1
1635 if (match(Op0, m_Not(m_Specific(Op1))) ||
1636 match(Op1, m_Not(m_Specific(Op0))))
1637 return Constant::getAllOnesValue(Op0->getType());
1639 // Try some generic simplifications for associative operations.
1640 if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, Q,
1644 // And distributes over Xor. Try some generic simplifications based on this.
1645 if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And,
1649 // Threading Xor over selects and phi nodes is pointless, so don't bother.
1650 // Threading over the select in "A ^ select(cond, B, C)" means evaluating
1651 // "A^B" and "A^C" and seeing if they are equal; but they are equal if and
1652 // only if B and C are equal. If B and C are equal then (since we assume
1653 // that operands have already been simplified) "select(cond, B, C)" should
1654 // have been simplified to the common value of B and C already. Analysing
1655 // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
1656 // for threading over phi nodes.
1661 Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const DataLayout *TD,
1662 const TargetLibraryInfo *TLI,
1663 const DominatorTree *DT) {
1664 return ::SimplifyXorInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1667 static Type *GetCompareTy(Value *Op) {
1668 return CmpInst::makeCmpResultType(Op->getType());
1671 /// ExtractEquivalentCondition - Rummage around inside V looking for something
1672 /// equivalent to the comparison "LHS Pred RHS". Return such a value if found,
1673 /// otherwise return null. Helper function for analyzing max/min idioms.
1674 static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred,
1675 Value *LHS, Value *RHS) {
1676 SelectInst *SI = dyn_cast<SelectInst>(V);
1679 CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
1682 Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1);
1683 if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS)
1685 if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) &&
1686 LHS == CmpRHS && RHS == CmpLHS)
1691 static Constant *computePointerICmp(const DataLayout *TD,
1692 CmpInst::Predicate Pred,
1693 Value *LHS, Value *RHS) {
1694 // We can only fold certain predicates on pointer comparisons.
1699 // Equality comaprisons are easy to fold.
1700 case CmpInst::ICMP_EQ:
1701 case CmpInst::ICMP_NE:
1704 // We can only handle unsigned relational comparisons because 'inbounds' on
1705 // a GEP only protects against unsigned wrapping.
1706 case CmpInst::ICMP_UGT:
1707 case CmpInst::ICMP_UGE:
1708 case CmpInst::ICMP_ULT:
1709 case CmpInst::ICMP_ULE:
1710 // However, we have to switch them to their signed variants to handle
1711 // negative indices from the base pointer.
1712 Pred = ICmpInst::getSignedPredicate(Pred);
1716 Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS);
1717 Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS);
1719 // If LHS and RHS are not related via constant offsets to the same base
1720 // value, there is nothing we can do here.
1724 return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset);
1727 /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
1728 /// fold the result. If not, this returns null.
1729 static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
1730 const Query &Q, unsigned MaxRecurse) {
1731 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
1732 assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
1734 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
1735 if (Constant *CRHS = dyn_cast<Constant>(RHS))
1736 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI);
1738 // If we have a constant, make sure it is on the RHS.
1739 std::swap(LHS, RHS);
1740 Pred = CmpInst::getSwappedPredicate(Pred);
1743 Type *ITy = GetCompareTy(LHS); // The return type.
1744 Type *OpTy = LHS->getType(); // The operand type.
1746 // icmp X, X -> true/false
1747 // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false
1748 // because X could be 0.
1749 if (LHS == RHS || isa<UndefValue>(RHS))
1750 return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
1752 // Special case logic when the operands have i1 type.
1753 if (OpTy->getScalarType()->isIntegerTy(1)) {
1756 case ICmpInst::ICMP_EQ:
1758 if (match(RHS, m_One()))
1761 case ICmpInst::ICMP_NE:
1763 if (match(RHS, m_Zero()))
1766 case ICmpInst::ICMP_UGT:
1768 if (match(RHS, m_Zero()))
1771 case ICmpInst::ICMP_UGE:
1773 if (match(RHS, m_One()))
1776 case ICmpInst::ICMP_SLT:
1778 if (match(RHS, m_Zero()))
1781 case ICmpInst::ICMP_SLE:
1783 if (match(RHS, m_One()))
1789 // icmp <object*>, <object*/null> - Different identified objects have
1790 // different addresses (unless null), and what's more the address of an
1791 // identified local is never equal to another argument (again, barring null).
1792 // Note that generalizing to the case where LHS is a global variable address
1793 // or null is pointless, since if both LHS and RHS are constants then we
1794 // already constant folded the compare, and if only one of them is then we
1795 // moved it to RHS already.
1796 Value *LHSPtr = LHS->stripPointerCasts();
1797 Value *RHSPtr = RHS->stripPointerCasts();
1798 if (LHSPtr == RHSPtr)
1799 return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
1801 // Be more aggressive about stripping pointer adjustments when checking a
1802 // comparison of an alloca address to another object. We can rip off all
1803 // inbounds GEP operations, even if they are variable.
1804 LHSPtr = LHSPtr->stripInBoundsOffsets();
1805 if (llvm::isIdentifiedObject(LHSPtr)) {
1806 RHSPtr = RHSPtr->stripInBoundsOffsets();
1807 if (llvm::isKnownNonNull(LHSPtr) || llvm::isKnownNonNull(RHSPtr)) {
1808 // If both sides are different identified objects, they aren't equal
1809 // unless they're null.
1810 if (LHSPtr != RHSPtr && llvm::isIdentifiedObject(RHSPtr) &&
1811 Pred == CmpInst::ICMP_EQ)
1812 return ConstantInt::get(ITy, false);
1814 // A local identified object (alloca or noalias call) can't equal any
1815 // incoming argument, unless they're both null or they belong to
1816 // different functions. The latter happens during inlining.
1817 if (Instruction *LHSInst = dyn_cast<Instruction>(LHSPtr))
1818 if (Argument *RHSArg = dyn_cast<Argument>(RHSPtr))
1819 if (LHSInst->getParent()->getParent() == RHSArg->getParent() &&
1820 Pred == CmpInst::ICMP_EQ)
1821 return ConstantInt::get(ITy, false);
1824 // Assume that the constant null is on the right.
1825 if (llvm::isKnownNonNull(LHSPtr) && isa<ConstantPointerNull>(RHSPtr)) {
1826 if (Pred == CmpInst::ICMP_EQ)
1827 return ConstantInt::get(ITy, false);
1828 else if (Pred == CmpInst::ICMP_NE)
1829 return ConstantInt::get(ITy, true);
1833 // If we are comparing with zero then try hard since this is a common case.
1834 if (match(RHS, m_Zero())) {
1835 bool LHSKnownNonNegative, LHSKnownNegative;
1837 default: llvm_unreachable("Unknown ICmp predicate!");
1838 case ICmpInst::ICMP_ULT:
1839 return getFalse(ITy);
1840 case ICmpInst::ICMP_UGE:
1841 return getTrue(ITy);
1842 case ICmpInst::ICMP_EQ:
1843 case ICmpInst::ICMP_ULE:
1844 if (isKnownNonZero(LHS, Q.TD))
1845 return getFalse(ITy);
1847 case ICmpInst::ICMP_NE:
1848 case ICmpInst::ICMP_UGT:
1849 if (isKnownNonZero(LHS, Q.TD))
1850 return getTrue(ITy);
1852 case ICmpInst::ICMP_SLT:
1853 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1854 if (LHSKnownNegative)
1855 return getTrue(ITy);
1856 if (LHSKnownNonNegative)
1857 return getFalse(ITy);
1859 case ICmpInst::ICMP_SLE:
1860 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1861 if (LHSKnownNegative)
1862 return getTrue(ITy);
1863 if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD))
1864 return getFalse(ITy);
1866 case ICmpInst::ICMP_SGE:
1867 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1868 if (LHSKnownNegative)
1869 return getFalse(ITy);
1870 if (LHSKnownNonNegative)
1871 return getTrue(ITy);
1873 case ICmpInst::ICMP_SGT:
1874 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1875 if (LHSKnownNegative)
1876 return getFalse(ITy);
1877 if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD))
1878 return getTrue(ITy);
1883 // See if we are doing a comparison with a constant integer.
1884 if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
1885 // Rule out tautological comparisons (eg., ult 0 or uge 0).
1886 ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue());
1887 if (RHS_CR.isEmptySet())
1888 return ConstantInt::getFalse(CI->getContext());
1889 if (RHS_CR.isFullSet())
1890 return ConstantInt::getTrue(CI->getContext());
1892 // Many binary operators with constant RHS have easy to compute constant
1893 // range. Use them to check whether the comparison is a tautology.
1894 uint32_t Width = CI->getBitWidth();
1895 APInt Lower = APInt(Width, 0);
1896 APInt Upper = APInt(Width, 0);
1898 if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) {
1899 // 'urem x, CI2' produces [0, CI2).
1900 Upper = CI2->getValue();
1901 } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) {
1902 // 'srem x, CI2' produces (-|CI2|, |CI2|).
1903 Upper = CI2->getValue().abs();
1904 Lower = (-Upper) + 1;
1905 } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) {
1906 // 'udiv CI2, x' produces [0, CI2].
1907 Upper = CI2->getValue() + 1;
1908 } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) {
1909 // 'udiv x, CI2' produces [0, UINT_MAX / CI2].
1910 APInt NegOne = APInt::getAllOnesValue(Width);
1912 Upper = NegOne.udiv(CI2->getValue()) + 1;
1913 } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) {
1914 // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2].
1915 APInt IntMin = APInt::getSignedMinValue(Width);
1916 APInt IntMax = APInt::getSignedMaxValue(Width);
1917 APInt Val = CI2->getValue().abs();
1918 if (!Val.isMinValue()) {
1919 Lower = IntMin.sdiv(Val);
1920 Upper = IntMax.sdiv(Val) + 1;
1922 } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {
1923 // 'lshr x, CI2' produces [0, UINT_MAX >> CI2].
1924 APInt NegOne = APInt::getAllOnesValue(Width);
1925 if (CI2->getValue().ult(Width))
1926 Upper = NegOne.lshr(CI2->getValue()) + 1;
1927 } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) {
1928 // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2].
1929 APInt IntMin = APInt::getSignedMinValue(Width);
1930 APInt IntMax = APInt::getSignedMaxValue(Width);
1931 if (CI2->getValue().ult(Width)) {
1932 Lower = IntMin.ashr(CI2->getValue());
1933 Upper = IntMax.ashr(CI2->getValue()) + 1;
1935 } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) {
1936 // 'or x, CI2' produces [CI2, UINT_MAX].
1937 Lower = CI2->getValue();
1938 } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) {
1939 // 'and x, CI2' produces [0, CI2].
1940 Upper = CI2->getValue() + 1;
1942 if (Lower != Upper) {
1943 ConstantRange LHS_CR = ConstantRange(Lower, Upper);
1944 if (RHS_CR.contains(LHS_CR))
1945 return ConstantInt::getTrue(RHS->getContext());
1946 if (RHS_CR.inverse().contains(LHS_CR))
1947 return ConstantInt::getFalse(RHS->getContext());
1951 // Compare of cast, for example (zext X) != 0 -> X != 0
1952 if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
1953 Instruction *LI = cast<CastInst>(LHS);
1954 Value *SrcOp = LI->getOperand(0);
1955 Type *SrcTy = SrcOp->getType();
1956 Type *DstTy = LI->getType();
1958 // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
1959 // if the integer type is the same size as the pointer type.
1960 if (MaxRecurse && Q.TD && isa<PtrToIntInst>(LI) &&
1961 Q.TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) {
1962 if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
1963 // Transfer the cast to the constant.
1964 if (Value *V = SimplifyICmpInst(Pred, SrcOp,
1965 ConstantExpr::getIntToPtr(RHSC, SrcTy),
1968 } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) {
1969 if (RI->getOperand(0)->getType() == SrcTy)
1970 // Compare without the cast.
1971 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
1977 if (isa<ZExtInst>(LHS)) {
1978 // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
1980 if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) {
1981 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
1982 // Compare X and Y. Note that signed predicates become unsigned.
1983 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
1984 SrcOp, RI->getOperand(0), Q,
1988 // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
1989 // too. If not, then try to deduce the result of the comparison.
1990 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
1991 // Compute the constant that would happen if we truncated to SrcTy then
1992 // reextended to DstTy.
1993 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
1994 Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy);
1996 // If the re-extended constant didn't change then this is effectively
1997 // also a case of comparing two zero-extended values.
1998 if (RExt == CI && MaxRecurse)
1999 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
2000 SrcOp, Trunc, Q, MaxRecurse-1))
2003 // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
2004 // there. Use this to work out the result of the comparison.
2007 default: llvm_unreachable("Unknown ICmp predicate!");
2009 case ICmpInst::ICMP_EQ:
2010 case ICmpInst::ICMP_UGT:
2011 case ICmpInst::ICMP_UGE:
2012 return ConstantInt::getFalse(CI->getContext());
2014 case ICmpInst::ICMP_NE:
2015 case ICmpInst::ICMP_ULT:
2016 case ICmpInst::ICMP_ULE:
2017 return ConstantInt::getTrue(CI->getContext());
2019 // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
2020 // is non-negative then LHS <s RHS.
2021 case ICmpInst::ICMP_SGT:
2022 case ICmpInst::ICMP_SGE:
2023 return CI->getValue().isNegative() ?
2024 ConstantInt::getTrue(CI->getContext()) :
2025 ConstantInt::getFalse(CI->getContext());
2027 case ICmpInst::ICMP_SLT:
2028 case ICmpInst::ICMP_SLE:
2029 return CI->getValue().isNegative() ?
2030 ConstantInt::getFalse(CI->getContext()) :
2031 ConstantInt::getTrue(CI->getContext());
2037 if (isa<SExtInst>(LHS)) {
2038 // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
2040 if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) {
2041 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
2042 // Compare X and Y. Note that the predicate does not change.
2043 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
2047 // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
2048 // too. If not, then try to deduce the result of the comparison.
2049 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2050 // Compute the constant that would happen if we truncated to SrcTy then
2051 // reextended to DstTy.
2052 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
2053 Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy);
2055 // If the re-extended constant didn't change then this is effectively
2056 // also a case of comparing two sign-extended values.
2057 if (RExt == CI && MaxRecurse)
2058 if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1))
2061 // Otherwise the upper bits of LHS are all equal, while RHS has varying
2062 // bits there. Use this to work out the result of the comparison.
2065 default: llvm_unreachable("Unknown ICmp predicate!");
2066 case ICmpInst::ICMP_EQ:
2067 return ConstantInt::getFalse(CI->getContext());
2068 case ICmpInst::ICMP_NE:
2069 return ConstantInt::getTrue(CI->getContext());
2071 // If RHS is non-negative then LHS <s RHS. If RHS is negative then
2073 case ICmpInst::ICMP_SGT:
2074 case ICmpInst::ICMP_SGE:
2075 return CI->getValue().isNegative() ?
2076 ConstantInt::getTrue(CI->getContext()) :
2077 ConstantInt::getFalse(CI->getContext());
2078 case ICmpInst::ICMP_SLT:
2079 case ICmpInst::ICMP_SLE:
2080 return CI->getValue().isNegative() ?
2081 ConstantInt::getFalse(CI->getContext()) :
2082 ConstantInt::getTrue(CI->getContext());
2084 // If LHS is non-negative then LHS <u RHS. If LHS is negative then
2086 case ICmpInst::ICMP_UGT:
2087 case ICmpInst::ICMP_UGE:
2088 // Comparison is true iff the LHS <s 0.
2090 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
2091 Constant::getNullValue(SrcTy),
2095 case ICmpInst::ICMP_ULT:
2096 case ICmpInst::ICMP_ULE:
2097 // Comparison is true iff the LHS >=s 0.
2099 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
2100 Constant::getNullValue(SrcTy),
2110 // Special logic for binary operators.
2111 BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS);
2112 BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
2113 if (MaxRecurse && (LBO || RBO)) {
2114 // Analyze the case when either LHS or RHS is an add instruction.
2115 Value *A = 0, *B = 0, *C = 0, *D = 0;
2116 // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
2117 bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
2118 if (LBO && LBO->getOpcode() == Instruction::Add) {
2119 A = LBO->getOperand(0); B = LBO->getOperand(1);
2120 NoLHSWrapProblem = ICmpInst::isEquality(Pred) ||
2121 (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) ||
2122 (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap());
2124 if (RBO && RBO->getOpcode() == Instruction::Add) {
2125 C = RBO->getOperand(0); D = RBO->getOperand(1);
2126 NoRHSWrapProblem = ICmpInst::isEquality(Pred) ||
2127 (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) ||
2128 (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap());
2131 // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
2132 if ((A == RHS || B == RHS) && NoLHSWrapProblem)
2133 if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A,
2134 Constant::getNullValue(RHS->getType()),
2138 // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
2139 if ((C == LHS || D == LHS) && NoRHSWrapProblem)
2140 if (Value *V = SimplifyICmpInst(Pred,
2141 Constant::getNullValue(LHS->getType()),
2142 C == LHS ? D : C, Q, MaxRecurse-1))
2145 // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
2146 if (A && C && (A == C || A == D || B == C || B == D) &&
2147 NoLHSWrapProblem && NoRHSWrapProblem) {
2148 // Determine Y and Z in the form icmp (X+Y), (X+Z).
2151 // C + B == C + D -> B == D
2154 } else if (A == D) {
2155 // D + B == C + D -> B == C
2158 } else if (B == C) {
2159 // A + C == C + D -> A == D
2164 // A + D == C + D -> A == C
2168 if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))
2173 if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
2174 bool KnownNonNegative, KnownNegative;
2178 case ICmpInst::ICMP_SGT:
2179 case ICmpInst::ICMP_SGE:
2180 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
2181 if (!KnownNonNegative)
2184 case ICmpInst::ICMP_EQ:
2185 case ICmpInst::ICMP_UGT:
2186 case ICmpInst::ICMP_UGE:
2187 return getFalse(ITy);
2188 case ICmpInst::ICMP_SLT:
2189 case ICmpInst::ICMP_SLE:
2190 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
2191 if (!KnownNonNegative)
2194 case ICmpInst::ICMP_NE:
2195 case ICmpInst::ICMP_ULT:
2196 case ICmpInst::ICMP_ULE:
2197 return getTrue(ITy);
2200 if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
2201 bool KnownNonNegative, KnownNegative;
2205 case ICmpInst::ICMP_SGT:
2206 case ICmpInst::ICMP_SGE:
2207 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
2208 if (!KnownNonNegative)
2211 case ICmpInst::ICMP_NE:
2212 case ICmpInst::ICMP_UGT:
2213 case ICmpInst::ICMP_UGE:
2214 return getTrue(ITy);
2215 case ICmpInst::ICMP_SLT:
2216 case ICmpInst::ICMP_SLE:
2217 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
2218 if (!KnownNonNegative)
2221 case ICmpInst::ICMP_EQ:
2222 case ICmpInst::ICMP_ULT:
2223 case ICmpInst::ICMP_ULE:
2224 return getFalse(ITy);
2229 if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) {
2230 // icmp pred (X /u Y), X
2231 if (Pred == ICmpInst::ICMP_UGT)
2232 return getFalse(ITy);
2233 if (Pred == ICmpInst::ICMP_ULE)
2234 return getTrue(ITy);
2237 if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
2238 LBO->getOperand(1) == RBO->getOperand(1)) {
2239 switch (LBO->getOpcode()) {
2241 case Instruction::UDiv:
2242 case Instruction::LShr:
2243 if (ICmpInst::isSigned(Pred))
2246 case Instruction::SDiv:
2247 case Instruction::AShr:
2248 if (!LBO->isExact() || !RBO->isExact())
2250 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2251 RBO->getOperand(0), Q, MaxRecurse-1))
2254 case Instruction::Shl: {
2255 bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap();
2256 bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap();
2259 if (!NSW && ICmpInst::isSigned(Pred))
2261 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2262 RBO->getOperand(0), Q, MaxRecurse-1))
2269 // Simplify comparisons involving max/min.
2271 CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
2272 CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
2274 // Signed variants on "max(a,b)>=a -> true".
2275 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2276 if (A != RHS) std::swap(A, B); // smax(A, B) pred A.
2277 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2278 // We analyze this as smax(A, B) pred A.
2280 } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
2281 (A == LHS || B == LHS)) {
2282 if (A != LHS) std::swap(A, B); // A pred smax(A, B).
2283 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2284 // We analyze this as smax(A, B) swapped-pred A.
2285 P = CmpInst::getSwappedPredicate(Pred);
2286 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2287 (A == RHS || B == RHS)) {
2288 if (A != RHS) std::swap(A, B); // smin(A, B) pred A.
2289 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2290 // We analyze this as smax(-A, -B) swapped-pred -A.
2291 // Note that we do not need to actually form -A or -B thanks to EqP.
2292 P = CmpInst::getSwappedPredicate(Pred);
2293 } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
2294 (A == LHS || B == LHS)) {
2295 if (A != LHS) std::swap(A, B); // A pred smin(A, B).
2296 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2297 // We analyze this as smax(-A, -B) pred -A.
2298 // Note that we do not need to actually form -A or -B thanks to EqP.
2301 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2302 // Cases correspond to "max(A, B) p A".
2306 case CmpInst::ICMP_EQ:
2307 case CmpInst::ICMP_SLE:
2308 // Equivalent to "A EqP B". This may be the same as the condition tested
2309 // in the max/min; if so, we can just return that.
2310 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2312 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2314 // Otherwise, see if "A EqP B" simplifies.
2316 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2319 case CmpInst::ICMP_NE:
2320 case CmpInst::ICMP_SGT: {
2321 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2322 // Equivalent to "A InvEqP B". This may be the same as the condition
2323 // tested in the max/min; if so, we can just return that.
2324 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2326 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2328 // Otherwise, see if "A InvEqP B" simplifies.
2330 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2334 case CmpInst::ICMP_SGE:
2336 return getTrue(ITy);
2337 case CmpInst::ICMP_SLT:
2339 return getFalse(ITy);
2343 // Unsigned variants on "max(a,b)>=a -> true".
2344 P = CmpInst::BAD_ICMP_PREDICATE;
2345 if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2346 if (A != RHS) std::swap(A, B); // umax(A, B) pred A.
2347 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2348 // We analyze this as umax(A, B) pred A.
2350 } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
2351 (A == LHS || B == LHS)) {
2352 if (A != LHS) std::swap(A, B); // A pred umax(A, B).
2353 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2354 // We analyze this as umax(A, B) swapped-pred A.
2355 P = CmpInst::getSwappedPredicate(Pred);
2356 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
2357 (A == RHS || B == RHS)) {
2358 if (A != RHS) std::swap(A, B); // umin(A, B) pred A.
2359 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2360 // We analyze this as umax(-A, -B) swapped-pred -A.
2361 // Note that we do not need to actually form -A or -B thanks to EqP.
2362 P = CmpInst::getSwappedPredicate(Pred);
2363 } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
2364 (A == LHS || B == LHS)) {
2365 if (A != LHS) std::swap(A, B); // A pred umin(A, B).
2366 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2367 // We analyze this as umax(-A, -B) pred -A.
2368 // Note that we do not need to actually form -A or -B thanks to EqP.
2371 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2372 // Cases correspond to "max(A, B) p A".
2376 case CmpInst::ICMP_EQ:
2377 case CmpInst::ICMP_ULE:
2378 // Equivalent to "A EqP B". This may be the same as the condition tested
2379 // in the max/min; if so, we can just return that.
2380 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2382 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2384 // Otherwise, see if "A EqP B" simplifies.
2386 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2389 case CmpInst::ICMP_NE:
2390 case CmpInst::ICMP_UGT: {
2391 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2392 // Equivalent to "A InvEqP B". This may be the same as the condition
2393 // tested in the max/min; if so, we can just return that.
2394 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2396 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2398 // Otherwise, see if "A InvEqP B" simplifies.
2400 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2404 case CmpInst::ICMP_UGE:
2406 return getTrue(ITy);
2407 case CmpInst::ICMP_ULT:
2409 return getFalse(ITy);
2413 // Variants on "max(x,y) >= min(x,z)".
2415 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) &&
2416 match(RHS, m_SMin(m_Value(C), m_Value(D))) &&
2417 (A == C || A == D || B == C || B == D)) {
2418 // max(x, ?) pred min(x, ?).
2419 if (Pred == CmpInst::ICMP_SGE)
2421 return getTrue(ITy);
2422 if (Pred == CmpInst::ICMP_SLT)
2424 return getFalse(ITy);
2425 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2426 match(RHS, m_SMax(m_Value(C), m_Value(D))) &&
2427 (A == C || A == D || B == C || B == D)) {
2428 // min(x, ?) pred max(x, ?).
2429 if (Pred == CmpInst::ICMP_SLE)
2431 return getTrue(ITy);
2432 if (Pred == CmpInst::ICMP_SGT)
2434 return getFalse(ITy);
2435 } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) &&
2436 match(RHS, m_UMin(m_Value(C), m_Value(D))) &&
2437 (A == C || A == D || B == C || B == D)) {
2438 // max(x, ?) pred min(x, ?).
2439 if (Pred == CmpInst::ICMP_UGE)
2441 return getTrue(ITy);
2442 if (Pred == CmpInst::ICMP_ULT)
2444 return getFalse(ITy);
2445 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
2446 match(RHS, m_UMax(m_Value(C), m_Value(D))) &&
2447 (A == C || A == D || B == C || B == D)) {
2448 // min(x, ?) pred max(x, ?).
2449 if (Pred == CmpInst::ICMP_ULE)
2451 return getTrue(ITy);
2452 if (Pred == CmpInst::ICMP_UGT)
2454 return getFalse(ITy);
2457 // Simplify comparisons of related pointers using a powerful, recursive
2458 // GEP-walk when we have target data available..
2459 if (LHS->getType()->isPointerTy())
2460 if (Constant *C = computePointerICmp(Q.TD, Pred, LHS, RHS))
2463 if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) {
2464 if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) {
2465 if (GLHS->getPointerOperand() == GRHS->getPointerOperand() &&
2466 GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() &&
2467 (ICmpInst::isEquality(Pred) ||
2468 (GLHS->isInBounds() && GRHS->isInBounds() &&
2469 Pred == ICmpInst::getSignedPredicate(Pred)))) {
2470 // The bases are equal and the indices are constant. Build a constant
2471 // expression GEP with the same indices and a null base pointer to see
2472 // what constant folding can make out of it.
2473 Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType());
2474 SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end());
2475 Constant *NewLHS = ConstantExpr::getGetElementPtr(Null, IndicesLHS);
2477 SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end());
2478 Constant *NewRHS = ConstantExpr::getGetElementPtr(Null, IndicesRHS);
2479 return ConstantExpr::getICmp(Pred, NewLHS, NewRHS);
2484 // If the comparison is with the result of a select instruction, check whether
2485 // comparing with either branch of the select always yields the same value.
2486 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
2487 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
2490 // If the comparison is with the result of a phi instruction, check whether
2491 // doing the compare with each incoming phi value yields a common result.
2492 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
2493 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
2499 Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2500 const DataLayout *TD,
2501 const TargetLibraryInfo *TLI,
2502 const DominatorTree *DT) {
2503 return ::SimplifyICmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
2507 /// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
2508 /// fold the result. If not, this returns null.
2509 static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2510 const Query &Q, unsigned MaxRecurse) {
2511 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
2512 assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
2514 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
2515 if (Constant *CRHS = dyn_cast<Constant>(RHS))
2516 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI);
2518 // If we have a constant, make sure it is on the RHS.
2519 std::swap(LHS, RHS);
2520 Pred = CmpInst::getSwappedPredicate(Pred);
2523 // Fold trivial predicates.
2524 if (Pred == FCmpInst::FCMP_FALSE)
2525 return ConstantInt::get(GetCompareTy(LHS), 0);
2526 if (Pred == FCmpInst::FCMP_TRUE)
2527 return ConstantInt::get(GetCompareTy(LHS), 1);
2529 if (isa<UndefValue>(RHS)) // fcmp pred X, undef -> undef
2530 return UndefValue::get(GetCompareTy(LHS));
2532 // fcmp x,x -> true/false. Not all compares are foldable.
2534 if (CmpInst::isTrueWhenEqual(Pred))
2535 return ConstantInt::get(GetCompareTy(LHS), 1);
2536 if (CmpInst::isFalseWhenEqual(Pred))
2537 return ConstantInt::get(GetCompareTy(LHS), 0);
2540 // Handle fcmp with constant RHS
2541 if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
2542 // If the constant is a nan, see if we can fold the comparison based on it.
2543 if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) {
2544 if (CFP->getValueAPF().isNaN()) {
2545 if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo"
2546 return ConstantInt::getFalse(CFP->getContext());
2547 assert(FCmpInst::isUnordered(Pred) &&
2548 "Comparison must be either ordered or unordered!");
2549 // True if unordered.
2550 return ConstantInt::getTrue(CFP->getContext());
2552 // Check whether the constant is an infinity.
2553 if (CFP->getValueAPF().isInfinity()) {
2554 if (CFP->getValueAPF().isNegative()) {
2556 case FCmpInst::FCMP_OLT:
2557 // No value is ordered and less than negative infinity.
2558 return ConstantInt::getFalse(CFP->getContext());
2559 case FCmpInst::FCMP_UGE:
2560 // All values are unordered with or at least negative infinity.
2561 return ConstantInt::getTrue(CFP->getContext());
2567 case FCmpInst::FCMP_OGT:
2568 // No value is ordered and greater than infinity.
2569 return ConstantInt::getFalse(CFP->getContext());
2570 case FCmpInst::FCMP_ULE:
2571 // All values are unordered with and at most infinity.
2572 return ConstantInt::getTrue(CFP->getContext());
2581 // If the comparison is with the result of a select instruction, check whether
2582 // comparing with either branch of the select always yields the same value.
2583 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
2584 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
2587 // If the comparison is with the result of a phi instruction, check whether
2588 // doing the compare with each incoming phi value yields a common result.
2589 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
2590 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
2596 Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2597 const DataLayout *TD,
2598 const TargetLibraryInfo *TLI,
2599 const DominatorTree *DT) {
2600 return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
2604 /// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
2605 /// the result. If not, this returns null.
2606 static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
2607 Value *FalseVal, const Query &Q,
2608 unsigned MaxRecurse) {
2609 // select true, X, Y -> X
2610 // select false, X, Y -> Y
2611 if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal))
2612 return CB->getZExtValue() ? TrueVal : FalseVal;
2614 // select C, X, X -> X
2615 if (TrueVal == FalseVal)
2618 if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
2619 if (isa<Constant>(TrueVal))
2623 if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
2625 if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
2631 Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
2632 const DataLayout *TD,
2633 const TargetLibraryInfo *TLI,
2634 const DominatorTree *DT) {
2635 return ::SimplifySelectInst(Cond, TrueVal, FalseVal, Query (TD, TLI, DT),
2639 /// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
2640 /// fold the result. If not, this returns null.
2641 static Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const Query &Q, unsigned) {
2642 // The type of the GEP pointer operand.
2643 PointerType *PtrTy = dyn_cast<PointerType>(Ops[0]->getType());
2644 // The GEP pointer operand is not a pointer, it's a vector of pointers.
2648 // getelementptr P -> P.
2649 if (Ops.size() == 1)
2652 if (isa<UndefValue>(Ops[0])) {
2653 // Compute the (pointer) type returned by the GEP instruction.
2654 Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1));
2655 Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace());
2656 return UndefValue::get(GEPTy);
2659 if (Ops.size() == 2) {
2660 // getelementptr P, 0 -> P.
2661 if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1]))
2664 // getelementptr P, N -> P if P points to a type of zero size.
2666 Type *Ty = PtrTy->getElementType();
2667 if (Ty->isSized() && Q.TD->getTypeAllocSize(Ty) == 0)
2672 // Check to see if this is constant foldable.
2673 for (unsigned i = 0, e = Ops.size(); i != e; ++i)
2674 if (!isa<Constant>(Ops[i]))
2677 return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), Ops.slice(1));
2680 Value *llvm::SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout *TD,
2681 const TargetLibraryInfo *TLI,
2682 const DominatorTree *DT) {
2683 return ::SimplifyGEPInst(Ops, Query (TD, TLI, DT), RecursionLimit);
2686 /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
2687 /// can fold the result. If not, this returns null.
2688 static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
2689 ArrayRef<unsigned> Idxs, const Query &Q,
2691 if (Constant *CAgg = dyn_cast<Constant>(Agg))
2692 if (Constant *CVal = dyn_cast<Constant>(Val))
2693 return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs);
2695 // insertvalue x, undef, n -> x
2696 if (match(Val, m_Undef()))
2699 // insertvalue x, (extractvalue y, n), n
2700 if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val))
2701 if (EV->getAggregateOperand()->getType() == Agg->getType() &&
2702 EV->getIndices() == Idxs) {
2703 // insertvalue undef, (extractvalue y, n), n -> y
2704 if (match(Agg, m_Undef()))
2705 return EV->getAggregateOperand();
2707 // insertvalue y, (extractvalue y, n), n -> y
2708 if (Agg == EV->getAggregateOperand())
2715 Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val,
2716 ArrayRef<unsigned> Idxs,
2717 const DataLayout *TD,
2718 const TargetLibraryInfo *TLI,
2719 const DominatorTree *DT) {
2720 return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query (TD, TLI, DT),
2724 /// SimplifyPHINode - See if we can fold the given phi. If not, returns null.
2725 static Value *SimplifyPHINode(PHINode *PN, const Query &Q) {
2726 // If all of the PHI's incoming values are the same then replace the PHI node
2727 // with the common value.
2728 Value *CommonValue = 0;
2729 bool HasUndefInput = false;
2730 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
2731 Value *Incoming = PN->getIncomingValue(i);
2732 // If the incoming value is the phi node itself, it can safely be skipped.
2733 if (Incoming == PN) continue;
2734 if (isa<UndefValue>(Incoming)) {
2735 // Remember that we saw an undef value, but otherwise ignore them.
2736 HasUndefInput = true;
2739 if (CommonValue && Incoming != CommonValue)
2740 return 0; // Not the same, bail out.
2741 CommonValue = Incoming;
2744 // If CommonValue is null then all of the incoming values were either undef or
2745 // equal to the phi node itself.
2747 return UndefValue::get(PN->getType());
2749 // If we have a PHI node like phi(X, undef, X), where X is defined by some
2750 // instruction, we cannot return X as the result of the PHI node unless it
2751 // dominates the PHI block.
2753 return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : 0;
2758 static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
2759 if (Constant *C = dyn_cast<Constant>(Op))
2760 return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.TD, Q.TLI);
2765 Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *TD,
2766 const TargetLibraryInfo *TLI,
2767 const DominatorTree *DT) {
2768 return ::SimplifyTruncInst(Op, Ty, Query (TD, TLI, DT), RecursionLimit);
2771 //=== Helper functions for higher up the class hierarchy.
2773 /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
2774 /// fold the result. If not, this returns null.
2775 static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
2776 const Query &Q, unsigned MaxRecurse) {
2778 case Instruction::Add:
2779 return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
2781 case Instruction::FAdd:
2782 return SimplifyFAddInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
2784 case Instruction::Sub:
2785 return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
2787 case Instruction::FSub:
2788 return SimplifyFSubInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
2790 case Instruction::Mul: return SimplifyMulInst (LHS, RHS, Q, MaxRecurse);
2791 case Instruction::FMul:
2792 return SimplifyFMulInst (LHS, RHS, FastMathFlags(), Q, MaxRecurse);
2793 case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse);
2794 case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse);
2795 case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, Q, MaxRecurse);
2796 case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse);
2797 case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse);
2798 case Instruction::FRem: return SimplifyFRemInst(LHS, RHS, Q, MaxRecurse);
2799 case Instruction::Shl:
2800 return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
2802 case Instruction::LShr:
2803 return SimplifyLShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
2804 case Instruction::AShr:
2805 return SimplifyAShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
2806 case Instruction::And: return SimplifyAndInst(LHS, RHS, Q, MaxRecurse);
2807 case Instruction::Or: return SimplifyOrInst (LHS, RHS, Q, MaxRecurse);
2808 case Instruction::Xor: return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
2810 if (Constant *CLHS = dyn_cast<Constant>(LHS))
2811 if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
2812 Constant *COps[] = {CLHS, CRHS};
2813 return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.TD,
2817 // If the operation is associative, try some generic simplifications.
2818 if (Instruction::isAssociative(Opcode))
2819 if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse))
2822 // If the operation is with the result of a select instruction check whether
2823 // operating on either branch of the select always yields the same value.
2824 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
2825 if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse))
2828 // If the operation is with the result of a phi instruction, check whether
2829 // operating on all incoming values of the phi always yields the same value.
2830 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
2831 if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
2838 Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
2839 const DataLayout *TD, const TargetLibraryInfo *TLI,
2840 const DominatorTree *DT) {
2841 return ::SimplifyBinOp(Opcode, LHS, RHS, Query (TD, TLI, DT), RecursionLimit);
2844 /// SimplifyCmpInst - Given operands for a CmpInst, see if we can
2845 /// fold the result.
2846 static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2847 const Query &Q, unsigned MaxRecurse) {
2848 if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
2849 return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
2850 return SimplifyFCmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
2853 Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2854 const DataLayout *TD, const TargetLibraryInfo *TLI,
2855 const DominatorTree *DT) {
2856 return ::SimplifyCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
2860 template <typename IterTy>
2861 static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd,
2862 const Query &Q, unsigned MaxRecurse) {
2863 Type *Ty = V->getType();
2864 if (PointerType *PTy = dyn_cast<PointerType>(Ty))
2865 Ty = PTy->getElementType();
2866 FunctionType *FTy = cast<FunctionType>(Ty);
2868 // call undef -> undef
2869 if (isa<UndefValue>(V))
2870 return UndefValue::get(FTy->getReturnType());
2872 Function *F = dyn_cast<Function>(V);
2876 if (!canConstantFoldCallTo(F))
2879 SmallVector<Constant *, 4> ConstantArgs;
2880 ConstantArgs.reserve(ArgEnd - ArgBegin);
2881 for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) {
2882 Constant *C = dyn_cast<Constant>(*I);
2885 ConstantArgs.push_back(C);
2888 return ConstantFoldCall(F, ConstantArgs, Q.TLI);
2891 Value *llvm::SimplifyCall(Value *V, User::op_iterator ArgBegin,
2892 User::op_iterator ArgEnd, const DataLayout *TD,
2893 const TargetLibraryInfo *TLI,
2894 const DominatorTree *DT) {
2895 return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(TD, TLI, DT),
2899 Value *llvm::SimplifyCall(Value *V, ArrayRef<Value *> Args,
2900 const DataLayout *TD, const TargetLibraryInfo *TLI,
2901 const DominatorTree *DT) {
2902 return ::SimplifyCall(V, Args.begin(), Args.end(), Query(TD, TLI, DT),
2906 /// SimplifyInstruction - See if we can compute a simplified version of this
2907 /// instruction. If not, this returns null.
2908 Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout *TD,
2909 const TargetLibraryInfo *TLI,
2910 const DominatorTree *DT) {
2913 switch (I->getOpcode()) {
2915 Result = ConstantFoldInstruction(I, TD, TLI);
2917 case Instruction::FAdd:
2918 Result = SimplifyFAddInst(I->getOperand(0), I->getOperand(1),
2919 I->getFastMathFlags(), TD, TLI, DT);
2921 case Instruction::Add:
2922 Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1),
2923 cast<BinaryOperator>(I)->hasNoSignedWrap(),
2924 cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
2927 case Instruction::FSub:
2928 Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1),
2929 I->getFastMathFlags(), TD, TLI, DT);
2931 case Instruction::Sub:
2932 Result = SimplifySubInst(I->getOperand(0), I->getOperand(1),
2933 cast<BinaryOperator>(I)->hasNoSignedWrap(),
2934 cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
2937 case Instruction::FMul:
2938 Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1),
2939 I->getFastMathFlags(), TD, TLI, DT);
2941 case Instruction::Mul:
2942 Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2944 case Instruction::SDiv:
2945 Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2947 case Instruction::UDiv:
2948 Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2950 case Instruction::FDiv:
2951 Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2953 case Instruction::SRem:
2954 Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2956 case Instruction::URem:
2957 Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2959 case Instruction::FRem:
2960 Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2962 case Instruction::Shl:
2963 Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1),
2964 cast<BinaryOperator>(I)->hasNoSignedWrap(),
2965 cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
2968 case Instruction::LShr:
2969 Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1),
2970 cast<BinaryOperator>(I)->isExact(),
2973 case Instruction::AShr:
2974 Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1),
2975 cast<BinaryOperator>(I)->isExact(),
2978 case Instruction::And:
2979 Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2981 case Instruction::Or:
2982 Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2984 case Instruction::Xor:
2985 Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2987 case Instruction::ICmp:
2988 Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(),
2989 I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2991 case Instruction::FCmp:
2992 Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
2993 I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2995 case Instruction::Select:
2996 Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
2997 I->getOperand(2), TD, TLI, DT);
2999 case Instruction::GetElementPtr: {
3000 SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
3001 Result = SimplifyGEPInst(Ops, TD, TLI, DT);
3004 case Instruction::InsertValue: {
3005 InsertValueInst *IV = cast<InsertValueInst>(I);
3006 Result = SimplifyInsertValueInst(IV->getAggregateOperand(),
3007 IV->getInsertedValueOperand(),
3008 IV->getIndices(), TD, TLI, DT);
3011 case Instruction::PHI:
3012 Result = SimplifyPHINode(cast<PHINode>(I), Query (TD, TLI, DT));
3014 case Instruction::Call: {
3015 CallSite CS(cast<CallInst>(I));
3016 Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(),
3020 case Instruction::Trunc:
3021 Result = SimplifyTruncInst(I->getOperand(0), I->getType(), TD, TLI, DT);
3025 /// If called on unreachable code, the above logic may report that the
3026 /// instruction simplified to itself. Make life easier for users by
3027 /// detecting that case here, returning a safe value instead.
3028 return Result == I ? UndefValue::get(I->getType()) : Result;
3031 /// \brief Implementation of recursive simplification through an instructions
3034 /// This is the common implementation of the recursive simplification routines.
3035 /// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
3036 /// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
3037 /// instructions to process and attempt to simplify it using
3038 /// InstructionSimplify.
3040 /// This routine returns 'true' only when *it* simplifies something. The passed
3041 /// in simplified value does not count toward this.
3042 static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
3043 const DataLayout *TD,
3044 const TargetLibraryInfo *TLI,
3045 const DominatorTree *DT) {
3046 bool Simplified = false;
3047 SmallSetVector<Instruction *, 8> Worklist;
3049 // If we have an explicit value to collapse to, do that round of the
3050 // simplification loop by hand initially.
3052 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
3055 Worklist.insert(cast<Instruction>(*UI));
3057 // Replace the instruction with its simplified value.
3058 I->replaceAllUsesWith(SimpleV);
3060 // Gracefully handle edge cases where the instruction is not wired into any
3063 I->eraseFromParent();
3068 // Note that we must test the size on each iteration, the worklist can grow.
3069 for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
3072 // See if this instruction simplifies.
3073 SimpleV = SimplifyInstruction(I, TD, TLI, DT);
3079 // Stash away all the uses of the old instruction so we can check them for
3080 // recursive simplifications after a RAUW. This is cheaper than checking all
3081 // uses of To on the recursive step in most cases.
3082 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
3084 Worklist.insert(cast<Instruction>(*UI));
3086 // Replace the instruction with its simplified value.
3087 I->replaceAllUsesWith(SimpleV);
3089 // Gracefully handle edge cases where the instruction is not wired into any
3092 I->eraseFromParent();
3097 bool llvm::recursivelySimplifyInstruction(Instruction *I,
3098 const DataLayout *TD,
3099 const TargetLibraryInfo *TLI,
3100 const DominatorTree *DT) {
3101 return replaceAndRecursivelySimplifyImpl(I, 0, TD, TLI, DT);
3104 bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
3105 const DataLayout *TD,
3106 const TargetLibraryInfo *TLI,
3107 const DominatorTree *DT) {
3108 assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!");
3109 assert(SimpleV && "Must provide a simplified value.");
3110 return replaceAndRecursivelySimplifyImpl(I, SimpleV, TD, TLI, DT);