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.
666 static Constant *stripAndComputeConstantOffsets(const DataLayout &TD,
668 assert(V->getType()->isPointerTy());
670 unsigned IntPtrWidth = TD.getPointerSizeInBits();
671 APInt Offset = APInt::getNullValue(IntPtrWidth);
673 // Even though we don't look through PHI nodes, we could be called on an
674 // instruction in an unreachable block, which may be on a cycle.
675 SmallPtrSet<Value *, 4> Visited;
678 if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
679 if (!GEP->isInBounds() || !GEP->accumulateConstantOffset(TD, Offset))
681 V = GEP->getPointerOperand();
682 } else if (Operator::getOpcode(V) == Instruction::BitCast) {
683 V = cast<Operator>(V)->getOperand(0);
684 } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
685 if (GA->mayBeOverridden())
687 V = GA->getAliasee();
691 assert(V->getType()->isPointerTy() && "Unexpected operand type!");
692 } while (Visited.insert(V));
694 Type *IntPtrTy = TD.getIntPtrType(V->getContext());
695 return ConstantInt::get(IntPtrTy, Offset);
698 /// \brief Compute the constant difference between two pointer values.
699 /// If the difference is not a constant, returns zero.
700 static Constant *computePointerDifference(const DataLayout &TD,
701 Value *LHS, Value *RHS) {
702 Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS);
703 Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS);
705 // If LHS and RHS are not related via constant offsets to the same base
706 // value, there is nothing we can do here.
710 // Otherwise, the difference of LHS - RHS can be computed as:
712 // = (LHSOffset + Base) - (RHSOffset + Base)
713 // = LHSOffset - RHSOffset
714 return ConstantExpr::getSub(LHSOffset, RHSOffset);
717 /// SimplifySubInst - Given operands for a Sub, see if we can
718 /// fold the result. If not, this returns null.
719 static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
720 const Query &Q, unsigned MaxRecurse) {
721 if (Constant *CLHS = dyn_cast<Constant>(Op0))
722 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
723 Constant *Ops[] = { CLHS, CRHS };
724 return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(),
728 // X - undef -> undef
729 // undef - X -> undef
730 if (match(Op0, m_Undef()) || match(Op1, m_Undef()))
731 return UndefValue::get(Op0->getType());
734 if (match(Op1, m_Zero()))
739 return Constant::getNullValue(Op0->getType());
744 if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) ||
745 match(Op0, m_Shl(m_Specific(Op1), m_One())))
748 // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies.
749 // For example, (X + Y) - Y -> X; (Y + X) - Y -> X
750 Value *Y = 0, *Z = Op1;
751 if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z
752 // See if "V === Y - Z" simplifies.
753 if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1))
754 // It does! Now see if "X + V" simplifies.
755 if (Value *W = SimplifyBinOp(Instruction::Add, X, V, Q, MaxRecurse-1)) {
756 // It does, we successfully reassociated!
760 // See if "V === X - Z" simplifies.
761 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
762 // It does! Now see if "Y + V" simplifies.
763 if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, Q, MaxRecurse-1)) {
764 // It does, we successfully reassociated!
770 // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies.
771 // For example, X - (X + 1) -> -1
773 if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z)
774 // See if "V === X - Y" simplifies.
775 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
776 // It does! Now see if "V - Z" simplifies.
777 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, Q, MaxRecurse-1)) {
778 // It does, we successfully reassociated!
782 // See if "V === X - Z" simplifies.
783 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1))
784 // It does! Now see if "V - Y" simplifies.
785 if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, Q, MaxRecurse-1)) {
786 // It does, we successfully reassociated!
792 // Z - (X - Y) -> (Z - X) + Y if everything simplifies.
793 // For example, X - (X - Y) -> Y.
795 if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y)
796 // See if "V === Z - X" simplifies.
797 if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, Q, MaxRecurse-1))
798 // It does! Now see if "V + Y" simplifies.
799 if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, Q, MaxRecurse-1)) {
800 // It does, we successfully reassociated!
805 // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies.
806 if (MaxRecurse && match(Op0, m_Trunc(m_Value(X))) &&
807 match(Op1, m_Trunc(m_Value(Y))))
808 if (X->getType() == Y->getType())
809 // See if "V === X - Y" simplifies.
810 if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
811 // It does! Now see if "trunc V" simplifies.
812 if (Value *W = SimplifyTruncInst(V, Op0->getType(), Q, MaxRecurse-1))
813 // It does, return the simplified "trunc V".
816 // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...).
817 if (Q.TD && match(Op0, m_PtrToInt(m_Value(X))) &&
818 match(Op1, m_PtrToInt(m_Value(Y))))
819 if (Constant *Result = computePointerDifference(*Q.TD, X, Y))
820 return ConstantExpr::getIntegerCast(Result, Op0->getType(), true);
822 // Mul distributes over Sub. Try some generic simplifications based on this.
823 if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul,
828 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
829 if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1))
832 // Threading Sub over selects and phi nodes is pointless, so don't bother.
833 // Threading over the select in "A - select(cond, B, C)" means evaluating
834 // "A-B" and "A-C" and seeing if they are equal; but they are equal if and
835 // only if B and C are equal. If B and C are equal then (since we assume
836 // that operands have already been simplified) "select(cond, B, C)" should
837 // have been simplified to the common value of B and C already. Analysing
838 // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly
839 // for threading over phi nodes.
844 Value *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
845 const DataLayout *TD, const TargetLibraryInfo *TLI,
846 const DominatorTree *DT) {
847 return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
851 /// Given operands for an FAdd, see if we can fold the result. If not, this
853 static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
854 const Query &Q, unsigned MaxRecurse) {
855 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
856 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
857 Constant *Ops[] = { CLHS, CRHS };
858 return ConstantFoldInstOperands(Instruction::FAdd, CLHS->getType(),
862 // Canonicalize the constant to the RHS.
867 if (match(Op1, m_NegZero()))
870 // fadd X, 0 ==> X, when we know X is not -0
871 if (match(Op1, m_Zero()) &&
872 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
875 // fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
876 // where nnan and ninf have to occur at least once somewhere in this
879 if (match(Op1, m_FSub(m_AnyZero(), m_Specific(Op0))))
881 else if (match(Op0, m_FSub(m_AnyZero(), m_Specific(Op1))))
884 Instruction *FSub = cast<Instruction>(SubOp);
885 if ((FMF.noNaNs() || FSub->hasNoNaNs()) &&
886 (FMF.noInfs() || FSub->hasNoInfs()))
887 return Constant::getNullValue(Op0->getType());
893 /// Given operands for an FSub, see if we can fold the result. If not, this
895 static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
896 const Query &Q, unsigned MaxRecurse) {
897 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
898 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
899 Constant *Ops[] = { CLHS, CRHS };
900 return ConstantFoldInstOperands(Instruction::FSub, CLHS->getType(),
906 if (match(Op1, m_Zero()))
909 // fsub X, -0 ==> X, when we know X is not -0
910 if (match(Op1, m_NegZero()) &&
911 (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
914 // fsub 0, (fsub -0.0, X) ==> X
916 if (match(Op0, m_AnyZero())) {
917 if (match(Op1, m_FSub(m_NegZero(), m_Value(X))))
919 if (FMF.noSignedZeros() && match(Op1, m_FSub(m_AnyZero(), m_Value(X))))
923 // fsub nnan ninf x, x ==> 0.0
924 if (FMF.noNaNs() && FMF.noInfs() && Op0 == Op1)
925 return Constant::getNullValue(Op0->getType());
930 /// Given the operands for an FMul, see if we can fold the result
931 static Value *SimplifyFMulInst(Value *Op0, Value *Op1,
934 unsigned MaxRecurse) {
935 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
936 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
937 Constant *Ops[] = { CLHS, CRHS };
938 return ConstantFoldInstOperands(Instruction::FMul, CLHS->getType(),
942 // Canonicalize the constant to the RHS.
947 if (match(Op1, m_FPOne()))
950 // fmul nnan nsz X, 0 ==> 0
951 if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op1, m_AnyZero()))
957 /// SimplifyMulInst - Given operands for a Mul, see if we can
958 /// fold the result. If not, this returns null.
959 static Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q,
960 unsigned MaxRecurse) {
961 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
962 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
963 Constant *Ops[] = { CLHS, CRHS };
964 return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(),
968 // Canonicalize the constant to the RHS.
973 if (match(Op1, m_Undef()))
974 return Constant::getNullValue(Op0->getType());
977 if (match(Op1, m_Zero()))
981 if (match(Op1, m_One()))
984 // (X / Y) * Y -> X if the division is exact.
986 if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y
987 match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y)
991 if (MaxRecurse && Op0->getType()->isIntegerTy(1))
992 if (Value *V = SimplifyAndInst(Op0, Op1, Q, MaxRecurse-1))
995 // Try some generic simplifications for associative operations.
996 if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, Q,
1000 // Mul distributes over Add. Try some generic simplifications based on this.
1001 if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add,
1005 // If the operation is with the result of a select instruction, check whether
1006 // operating on either branch of the select always yields the same value.
1007 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1008 if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, Q,
1012 // If the operation is with the result of a phi instruction, check whether
1013 // operating on all incoming values of the phi always yields the same value.
1014 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1015 if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, Q,
1022 Value *llvm::SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1023 const DataLayout *TD, const TargetLibraryInfo *TLI,
1024 const DominatorTree *DT) {
1025 return ::SimplifyFAddInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit);
1028 Value *llvm::SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
1029 const DataLayout *TD, const TargetLibraryInfo *TLI,
1030 const DominatorTree *DT) {
1031 return ::SimplifyFSubInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit);
1034 Value *llvm::SimplifyFMulInst(Value *Op0, Value *Op1,
1036 const DataLayout *TD,
1037 const TargetLibraryInfo *TLI,
1038 const DominatorTree *DT) {
1039 return ::SimplifyFMulInst(Op0, Op1, FMF, Query (TD, TLI, DT), RecursionLimit);
1042 Value *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const DataLayout *TD,
1043 const TargetLibraryInfo *TLI,
1044 const DominatorTree *DT) {
1045 return ::SimplifyMulInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1048 /// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can
1049 /// fold the result. If not, this returns null.
1050 static Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
1051 const Query &Q, unsigned MaxRecurse) {
1052 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1053 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1054 Constant *Ops[] = { C0, C1 };
1055 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
1059 bool isSigned = Opcode == Instruction::SDiv;
1061 // X / undef -> undef
1062 if (match(Op1, m_Undef()))
1066 if (match(Op0, m_Undef()))
1067 return Constant::getNullValue(Op0->getType());
1069 // 0 / X -> 0, we don't need to preserve faults!
1070 if (match(Op0, m_Zero()))
1074 if (match(Op1, m_One()))
1077 if (Op0->getType()->isIntegerTy(1))
1078 // It can't be division by zero, hence it must be division by one.
1083 return ConstantInt::get(Op0->getType(), 1);
1085 // (X * Y) / Y -> X if the multiplication does not overflow.
1086 Value *X = 0, *Y = 0;
1087 if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) {
1088 if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1
1089 OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0);
1090 // If the Mul knows it does not overflow, then we are good to go.
1091 if ((isSigned && Mul->hasNoSignedWrap()) ||
1092 (!isSigned && Mul->hasNoUnsignedWrap()))
1094 // If X has the form X = A / Y then X * Y cannot overflow.
1095 if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X))
1096 if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y)
1100 // (X rem Y) / Y -> 0
1101 if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) ||
1102 (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1)))))
1103 return Constant::getNullValue(Op0->getType());
1105 // If the operation is with the result of a select instruction, check whether
1106 // operating on either branch of the select always yields the same value.
1107 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1108 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1111 // If the operation is with the result of a phi instruction, check whether
1112 // operating on all incoming values of the phi always yields the same value.
1113 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1114 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1120 /// SimplifySDivInst - Given operands for an SDiv, see if we can
1121 /// fold the result. If not, this returns null.
1122 static Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q,
1123 unsigned MaxRecurse) {
1124 if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse))
1130 Value *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const DataLayout *TD,
1131 const TargetLibraryInfo *TLI,
1132 const DominatorTree *DT) {
1133 return ::SimplifySDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1136 /// SimplifyUDivInst - Given operands for a UDiv, see if we can
1137 /// fold the result. If not, this returns null.
1138 static Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q,
1139 unsigned MaxRecurse) {
1140 if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse))
1146 Value *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const DataLayout *TD,
1147 const TargetLibraryInfo *TLI,
1148 const DominatorTree *DT) {
1149 return ::SimplifyUDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1152 static Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q,
1154 // undef / X -> undef (the undef could be a snan).
1155 if (match(Op0, m_Undef()))
1158 // X / undef -> undef
1159 if (match(Op1, m_Undef()))
1165 Value *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const DataLayout *TD,
1166 const TargetLibraryInfo *TLI,
1167 const DominatorTree *DT) {
1168 return ::SimplifyFDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1171 /// SimplifyRem - Given operands for an SRem or URem, see if we can
1172 /// fold the result. If not, this returns null.
1173 static Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1,
1174 const Query &Q, unsigned MaxRecurse) {
1175 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1176 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1177 Constant *Ops[] = { C0, C1 };
1178 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
1182 // X % undef -> undef
1183 if (match(Op1, m_Undef()))
1187 if (match(Op0, m_Undef()))
1188 return Constant::getNullValue(Op0->getType());
1190 // 0 % X -> 0, we don't need to preserve faults!
1191 if (match(Op0, m_Zero()))
1194 // X % 0 -> undef, we don't need to preserve faults!
1195 if (match(Op1, m_Zero()))
1196 return UndefValue::get(Op0->getType());
1199 if (match(Op1, m_One()))
1200 return Constant::getNullValue(Op0->getType());
1202 if (Op0->getType()->isIntegerTy(1))
1203 // It can't be remainder by zero, hence it must be remainder by one.
1204 return Constant::getNullValue(Op0->getType());
1208 return Constant::getNullValue(Op0->getType());
1210 // If the operation is with the result of a select instruction, check whether
1211 // operating on either branch of the select always yields the same value.
1212 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1213 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1216 // If the operation is with the result of a phi instruction, check whether
1217 // operating on all incoming values of the phi always yields the same value.
1218 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1219 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1225 /// SimplifySRemInst - Given operands for an SRem, see if we can
1226 /// fold the result. If not, this returns null.
1227 static Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q,
1228 unsigned MaxRecurse) {
1229 if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse))
1235 Value *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const DataLayout *TD,
1236 const TargetLibraryInfo *TLI,
1237 const DominatorTree *DT) {
1238 return ::SimplifySRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1241 /// SimplifyURemInst - Given operands for a URem, see if we can
1242 /// fold the result. If not, this returns null.
1243 static Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q,
1244 unsigned MaxRecurse) {
1245 if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse))
1251 Value *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const DataLayout *TD,
1252 const TargetLibraryInfo *TLI,
1253 const DominatorTree *DT) {
1254 return ::SimplifyURemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1257 static Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &,
1259 // undef % X -> undef (the undef could be a snan).
1260 if (match(Op0, m_Undef()))
1263 // X % undef -> undef
1264 if (match(Op1, m_Undef()))
1270 Value *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const DataLayout *TD,
1271 const TargetLibraryInfo *TLI,
1272 const DominatorTree *DT) {
1273 return ::SimplifyFRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1276 /// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can
1277 /// fold the result. If not, this returns null.
1278 static Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1,
1279 const Query &Q, unsigned MaxRecurse) {
1280 if (Constant *C0 = dyn_cast<Constant>(Op0)) {
1281 if (Constant *C1 = dyn_cast<Constant>(Op1)) {
1282 Constant *Ops[] = { C0, C1 };
1283 return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI);
1287 // 0 shift by X -> 0
1288 if (match(Op0, m_Zero()))
1291 // X shift by 0 -> X
1292 if (match(Op1, m_Zero()))
1295 // X shift by undef -> undef because it may shift by the bitwidth.
1296 if (match(Op1, m_Undef()))
1299 // Shifting by the bitwidth or more is undefined.
1300 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1))
1301 if (CI->getValue().getLimitedValue() >=
1302 Op0->getType()->getScalarSizeInBits())
1303 return UndefValue::get(Op0->getType());
1305 // If the operation is with the result of a select instruction, check whether
1306 // operating on either branch of the select always yields the same value.
1307 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1308 if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse))
1311 // If the operation is with the result of a phi instruction, check whether
1312 // operating on all incoming values of the phi always yields the same value.
1313 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1314 if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse))
1320 /// SimplifyShlInst - Given operands for an Shl, see if we can
1321 /// fold the result. If not, this returns null.
1322 static Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1323 const Query &Q, unsigned MaxRecurse) {
1324 if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse))
1328 if (match(Op0, m_Undef()))
1329 return Constant::getNullValue(Op0->getType());
1331 // (X >> A) << A -> X
1333 if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1)))))
1338 Value *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
1339 const DataLayout *TD, const TargetLibraryInfo *TLI,
1340 const DominatorTree *DT) {
1341 return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT),
1345 /// SimplifyLShrInst - Given operands for an LShr, see if we can
1346 /// fold the result. If not, this returns null.
1347 static Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1348 const Query &Q, unsigned MaxRecurse) {
1349 if (Value *V = SimplifyShift(Instruction::LShr, Op0, Op1, Q, MaxRecurse))
1353 if (match(Op0, m_Undef()))
1354 return Constant::getNullValue(Op0->getType());
1356 // (X << A) >> A -> X
1358 if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
1359 cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap())
1365 Value *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
1366 const DataLayout *TD,
1367 const TargetLibraryInfo *TLI,
1368 const DominatorTree *DT) {
1369 return ::SimplifyLShrInst(Op0, Op1, isExact, Query (TD, TLI, DT),
1373 /// SimplifyAShrInst - Given operands for an AShr, see if we can
1374 /// fold the result. If not, this returns null.
1375 static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1376 const Query &Q, unsigned MaxRecurse) {
1377 if (Value *V = SimplifyShift(Instruction::AShr, Op0, Op1, Q, MaxRecurse))
1380 // all ones >>a X -> all ones
1381 if (match(Op0, m_AllOnes()))
1384 // undef >>a X -> all ones
1385 if (match(Op0, m_Undef()))
1386 return Constant::getAllOnesValue(Op0->getType());
1388 // (X << A) >> A -> X
1390 if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) &&
1391 cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap())
1397 Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
1398 const DataLayout *TD,
1399 const TargetLibraryInfo *TLI,
1400 const DominatorTree *DT) {
1401 return ::SimplifyAShrInst(Op0, Op1, isExact, Query (TD, TLI, DT),
1405 /// SimplifyAndInst - Given operands for an And, see if we can
1406 /// fold the result. If not, this returns null.
1407 static Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q,
1408 unsigned MaxRecurse) {
1409 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1410 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1411 Constant *Ops[] = { CLHS, CRHS };
1412 return ConstantFoldInstOperands(Instruction::And, CLHS->getType(),
1416 // Canonicalize the constant to the RHS.
1417 std::swap(Op0, Op1);
1421 if (match(Op1, m_Undef()))
1422 return Constant::getNullValue(Op0->getType());
1429 if (match(Op1, m_Zero()))
1433 if (match(Op1, m_AllOnes()))
1436 // A & ~A = ~A & A = 0
1437 if (match(Op0, m_Not(m_Specific(Op1))) ||
1438 match(Op1, m_Not(m_Specific(Op0))))
1439 return Constant::getNullValue(Op0->getType());
1442 Value *A = 0, *B = 0;
1443 if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
1444 (A == Op1 || B == Op1))
1448 if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
1449 (A == Op0 || B == Op0))
1452 // A & (-A) = A if A is a power of two or zero.
1453 if (match(Op0, m_Neg(m_Specific(Op1))) ||
1454 match(Op1, m_Neg(m_Specific(Op0)))) {
1455 if (isKnownToBeAPowerOfTwo(Op0, /*OrZero*/true))
1457 if (isKnownToBeAPowerOfTwo(Op1, /*OrZero*/true))
1461 // Try some generic simplifications for associative operations.
1462 if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q,
1466 // And distributes over Or. Try some generic simplifications based on this.
1467 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or,
1471 // And distributes over Xor. Try some generic simplifications based on this.
1472 if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor,
1476 // Or distributes over And. Try some generic simplifications based on this.
1477 if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or,
1481 // If the operation is with the result of a select instruction, check whether
1482 // operating on either branch of the select always yields the same value.
1483 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1484 if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, Q,
1488 // If the operation is with the result of a phi instruction, check whether
1489 // operating on all incoming values of the phi always yields the same value.
1490 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1491 if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, Q,
1498 Value *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const DataLayout *TD,
1499 const TargetLibraryInfo *TLI,
1500 const DominatorTree *DT) {
1501 return ::SimplifyAndInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1504 /// SimplifyOrInst - Given operands for an Or, see if we can
1505 /// fold the result. If not, this returns null.
1506 static Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q,
1507 unsigned MaxRecurse) {
1508 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1509 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1510 Constant *Ops[] = { CLHS, CRHS };
1511 return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(),
1515 // Canonicalize the constant to the RHS.
1516 std::swap(Op0, Op1);
1520 if (match(Op1, m_Undef()))
1521 return Constant::getAllOnesValue(Op0->getType());
1528 if (match(Op1, m_Zero()))
1532 if (match(Op1, m_AllOnes()))
1535 // A | ~A = ~A | A = -1
1536 if (match(Op0, m_Not(m_Specific(Op1))) ||
1537 match(Op1, m_Not(m_Specific(Op0))))
1538 return Constant::getAllOnesValue(Op0->getType());
1541 Value *A = 0, *B = 0;
1542 if (match(Op0, m_And(m_Value(A), m_Value(B))) &&
1543 (A == Op1 || B == Op1))
1547 if (match(Op1, m_And(m_Value(A), m_Value(B))) &&
1548 (A == Op0 || B == Op0))
1551 // ~(A & ?) | A = -1
1552 if (match(Op0, m_Not(m_And(m_Value(A), m_Value(B)))) &&
1553 (A == Op1 || B == Op1))
1554 return Constant::getAllOnesValue(Op1->getType());
1556 // A | ~(A & ?) = -1
1557 if (match(Op1, m_Not(m_And(m_Value(A), m_Value(B)))) &&
1558 (A == Op0 || B == Op0))
1559 return Constant::getAllOnesValue(Op0->getType());
1561 // Try some generic simplifications for associative operations.
1562 if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q,
1566 // Or distributes over And. Try some generic simplifications based on this.
1567 if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, Q,
1571 // And distributes over Or. Try some generic simplifications based on this.
1572 if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And,
1576 // If the operation is with the result of a select instruction, check whether
1577 // operating on either branch of the select always yields the same value.
1578 if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1))
1579 if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, Q,
1583 // If the operation is with the result of a phi instruction, check whether
1584 // operating on all incoming values of the phi always yields the same value.
1585 if (isa<PHINode>(Op0) || isa<PHINode>(Op1))
1586 if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse))
1592 Value *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const DataLayout *TD,
1593 const TargetLibraryInfo *TLI,
1594 const DominatorTree *DT) {
1595 return ::SimplifyOrInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1598 /// SimplifyXorInst - Given operands for a Xor, see if we can
1599 /// fold the result. If not, this returns null.
1600 static Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q,
1601 unsigned MaxRecurse) {
1602 if (Constant *CLHS = dyn_cast<Constant>(Op0)) {
1603 if (Constant *CRHS = dyn_cast<Constant>(Op1)) {
1604 Constant *Ops[] = { CLHS, CRHS };
1605 return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(),
1609 // Canonicalize the constant to the RHS.
1610 std::swap(Op0, Op1);
1613 // A ^ undef -> undef
1614 if (match(Op1, m_Undef()))
1618 if (match(Op1, m_Zero()))
1623 return Constant::getNullValue(Op0->getType());
1625 // A ^ ~A = ~A ^ A = -1
1626 if (match(Op0, m_Not(m_Specific(Op1))) ||
1627 match(Op1, m_Not(m_Specific(Op0))))
1628 return Constant::getAllOnesValue(Op0->getType());
1630 // Try some generic simplifications for associative operations.
1631 if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, Q,
1635 // And distributes over Xor. Try some generic simplifications based on this.
1636 if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And,
1640 // Threading Xor over selects and phi nodes is pointless, so don't bother.
1641 // Threading over the select in "A ^ select(cond, B, C)" means evaluating
1642 // "A^B" and "A^C" and seeing if they are equal; but they are equal if and
1643 // only if B and C are equal. If B and C are equal then (since we assume
1644 // that operands have already been simplified) "select(cond, B, C)" should
1645 // have been simplified to the common value of B and C already. Analysing
1646 // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly
1647 // for threading over phi nodes.
1652 Value *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const DataLayout *TD,
1653 const TargetLibraryInfo *TLI,
1654 const DominatorTree *DT) {
1655 return ::SimplifyXorInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit);
1658 static Type *GetCompareTy(Value *Op) {
1659 return CmpInst::makeCmpResultType(Op->getType());
1662 /// ExtractEquivalentCondition - Rummage around inside V looking for something
1663 /// equivalent to the comparison "LHS Pred RHS". Return such a value if found,
1664 /// otherwise return null. Helper function for analyzing max/min idioms.
1665 static Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred,
1666 Value *LHS, Value *RHS) {
1667 SelectInst *SI = dyn_cast<SelectInst>(V);
1670 CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition());
1673 Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1);
1674 if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS)
1676 if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) &&
1677 LHS == CmpRHS && RHS == CmpLHS)
1682 static Constant *computePointerICmp(const DataLayout &TD,
1683 CmpInst::Predicate Pred,
1684 Value *LHS, Value *RHS) {
1685 // We can only fold certain predicates on pointer comparisons.
1690 // Equality comaprisons are easy to fold.
1691 case CmpInst::ICMP_EQ:
1692 case CmpInst::ICMP_NE:
1695 // We can only handle unsigned relational comparisons because 'inbounds' on
1696 // a GEP only protects against unsigned wrapping.
1697 case CmpInst::ICMP_UGT:
1698 case CmpInst::ICMP_UGE:
1699 case CmpInst::ICMP_ULT:
1700 case CmpInst::ICMP_ULE:
1701 // However, we have to switch them to their signed variants to handle
1702 // negative indices from the base pointer.
1703 Pred = ICmpInst::getSignedPredicate(Pred);
1707 Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS);
1708 Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS);
1710 // If LHS and RHS are not related via constant offsets to the same base
1711 // value, there is nothing we can do here.
1715 return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset);
1718 /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
1719 /// fold the result. If not, this returns null.
1720 static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
1721 const Query &Q, unsigned MaxRecurse) {
1722 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
1723 assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
1725 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
1726 if (Constant *CRHS = dyn_cast<Constant>(RHS))
1727 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI);
1729 // If we have a constant, make sure it is on the RHS.
1730 std::swap(LHS, RHS);
1731 Pred = CmpInst::getSwappedPredicate(Pred);
1734 Type *ITy = GetCompareTy(LHS); // The return type.
1735 Type *OpTy = LHS->getType(); // The operand type.
1737 // icmp X, X -> true/false
1738 // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false
1739 // because X could be 0.
1740 if (LHS == RHS || isa<UndefValue>(RHS))
1741 return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
1743 // Special case logic when the operands have i1 type.
1744 if (OpTy->getScalarType()->isIntegerTy(1)) {
1747 case ICmpInst::ICMP_EQ:
1749 if (match(RHS, m_One()))
1752 case ICmpInst::ICMP_NE:
1754 if (match(RHS, m_Zero()))
1757 case ICmpInst::ICMP_UGT:
1759 if (match(RHS, m_Zero()))
1762 case ICmpInst::ICMP_UGE:
1764 if (match(RHS, m_One()))
1767 case ICmpInst::ICMP_SLT:
1769 if (match(RHS, m_Zero()))
1772 case ICmpInst::ICMP_SLE:
1774 if (match(RHS, m_One()))
1780 // icmp <object*>, <object*/null> - Different identified objects have
1781 // different addresses (unless null), and what's more the address of an
1782 // identified local is never equal to another argument (again, barring null).
1783 // Note that generalizing to the case where LHS is a global variable address
1784 // or null is pointless, since if both LHS and RHS are constants then we
1785 // already constant folded the compare, and if only one of them is then we
1786 // moved it to RHS already.
1787 Value *LHSPtr = LHS->stripPointerCasts();
1788 Value *RHSPtr = RHS->stripPointerCasts();
1789 if (LHSPtr == RHSPtr)
1790 return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred));
1792 // Be more aggressive about stripping pointer adjustments when checking a
1793 // comparison of an alloca address to another object. We can rip off all
1794 // inbounds GEP operations, even if they are variable.
1795 LHSPtr = LHSPtr->stripInBoundsOffsets();
1796 if (llvm::isIdentifiedObject(LHSPtr)) {
1797 RHSPtr = RHSPtr->stripInBoundsOffsets();
1798 if (llvm::isKnownNonNull(LHSPtr) || llvm::isKnownNonNull(RHSPtr)) {
1799 // If both sides are different identified objects, they aren't equal
1800 // unless they're null.
1801 if (LHSPtr != RHSPtr && llvm::isIdentifiedObject(RHSPtr) &&
1802 Pred == CmpInst::ICMP_EQ)
1803 return ConstantInt::get(ITy, false);
1805 // A local identified object (alloca or noalias call) can't equal any
1806 // incoming argument, unless they're both null or they belong to
1807 // different functions. The latter happens during inlining.
1808 if (Instruction *LHSInst = dyn_cast<Instruction>(LHSPtr))
1809 if (Argument *RHSArg = dyn_cast<Argument>(RHSPtr))
1810 if (LHSInst->getParent()->getParent() == RHSArg->getParent() &&
1811 Pred == CmpInst::ICMP_EQ)
1812 return ConstantInt::get(ITy, false);
1815 // Assume that the constant null is on the right.
1816 if (llvm::isKnownNonNull(LHSPtr) && isa<ConstantPointerNull>(RHSPtr)) {
1817 if (Pred == CmpInst::ICMP_EQ)
1818 return ConstantInt::get(ITy, false);
1819 else if (Pred == CmpInst::ICMP_NE)
1820 return ConstantInt::get(ITy, true);
1822 } else if (Argument *LHSArg = dyn_cast<Argument>(LHSPtr)) {
1823 RHSPtr = RHSPtr->stripInBoundsOffsets();
1824 // An alloca can't be equal to an argument unless they come from separate
1825 // functions via inlining.
1826 if (AllocaInst *RHSInst = dyn_cast<AllocaInst>(RHSPtr)) {
1827 if (LHSArg->getParent() == RHSInst->getParent()->getParent()) {
1828 if (Pred == CmpInst::ICMP_EQ)
1829 return ConstantInt::get(ITy, false);
1830 else if (Pred == CmpInst::ICMP_NE)
1831 return ConstantInt::get(ITy, true);
1836 // If we are comparing with zero then try hard since this is a common case.
1837 if (match(RHS, m_Zero())) {
1838 bool LHSKnownNonNegative, LHSKnownNegative;
1840 default: llvm_unreachable("Unknown ICmp predicate!");
1841 case ICmpInst::ICMP_ULT:
1842 return getFalse(ITy);
1843 case ICmpInst::ICMP_UGE:
1844 return getTrue(ITy);
1845 case ICmpInst::ICMP_EQ:
1846 case ICmpInst::ICMP_ULE:
1847 if (isKnownNonZero(LHS, Q.TD))
1848 return getFalse(ITy);
1850 case ICmpInst::ICMP_NE:
1851 case ICmpInst::ICMP_UGT:
1852 if (isKnownNonZero(LHS, Q.TD))
1853 return getTrue(ITy);
1855 case ICmpInst::ICMP_SLT:
1856 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1857 if (LHSKnownNegative)
1858 return getTrue(ITy);
1859 if (LHSKnownNonNegative)
1860 return getFalse(ITy);
1862 case ICmpInst::ICMP_SLE:
1863 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1864 if (LHSKnownNegative)
1865 return getTrue(ITy);
1866 if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD))
1867 return getFalse(ITy);
1869 case ICmpInst::ICMP_SGE:
1870 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1871 if (LHSKnownNegative)
1872 return getFalse(ITy);
1873 if (LHSKnownNonNegative)
1874 return getTrue(ITy);
1876 case ICmpInst::ICMP_SGT:
1877 ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD);
1878 if (LHSKnownNegative)
1879 return getFalse(ITy);
1880 if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD))
1881 return getTrue(ITy);
1886 // See if we are doing a comparison with a constant integer.
1887 if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
1888 // Rule out tautological comparisons (eg., ult 0 or uge 0).
1889 ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue());
1890 if (RHS_CR.isEmptySet())
1891 return ConstantInt::getFalse(CI->getContext());
1892 if (RHS_CR.isFullSet())
1893 return ConstantInt::getTrue(CI->getContext());
1895 // Many binary operators with constant RHS have easy to compute constant
1896 // range. Use them to check whether the comparison is a tautology.
1897 uint32_t Width = CI->getBitWidth();
1898 APInt Lower = APInt(Width, 0);
1899 APInt Upper = APInt(Width, 0);
1901 if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) {
1902 // 'urem x, CI2' produces [0, CI2).
1903 Upper = CI2->getValue();
1904 } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) {
1905 // 'srem x, CI2' produces (-|CI2|, |CI2|).
1906 Upper = CI2->getValue().abs();
1907 Lower = (-Upper) + 1;
1908 } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) {
1909 // 'udiv CI2, x' produces [0, CI2].
1910 Upper = CI2->getValue() + 1;
1911 } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) {
1912 // 'udiv x, CI2' produces [0, UINT_MAX / CI2].
1913 APInt NegOne = APInt::getAllOnesValue(Width);
1915 Upper = NegOne.udiv(CI2->getValue()) + 1;
1916 } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) {
1917 // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2].
1918 APInt IntMin = APInt::getSignedMinValue(Width);
1919 APInt IntMax = APInt::getSignedMaxValue(Width);
1920 APInt Val = CI2->getValue().abs();
1921 if (!Val.isMinValue()) {
1922 Lower = IntMin.sdiv(Val);
1923 Upper = IntMax.sdiv(Val) + 1;
1925 } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) {
1926 // 'lshr x, CI2' produces [0, UINT_MAX >> CI2].
1927 APInt NegOne = APInt::getAllOnesValue(Width);
1928 if (CI2->getValue().ult(Width))
1929 Upper = NegOne.lshr(CI2->getValue()) + 1;
1930 } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) {
1931 // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2].
1932 APInt IntMin = APInt::getSignedMinValue(Width);
1933 APInt IntMax = APInt::getSignedMaxValue(Width);
1934 if (CI2->getValue().ult(Width)) {
1935 Lower = IntMin.ashr(CI2->getValue());
1936 Upper = IntMax.ashr(CI2->getValue()) + 1;
1938 } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) {
1939 // 'or x, CI2' produces [CI2, UINT_MAX].
1940 Lower = CI2->getValue();
1941 } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) {
1942 // 'and x, CI2' produces [0, CI2].
1943 Upper = CI2->getValue() + 1;
1945 if (Lower != Upper) {
1946 ConstantRange LHS_CR = ConstantRange(Lower, Upper);
1947 if (RHS_CR.contains(LHS_CR))
1948 return ConstantInt::getTrue(RHS->getContext());
1949 if (RHS_CR.inverse().contains(LHS_CR))
1950 return ConstantInt::getFalse(RHS->getContext());
1954 // Compare of cast, for example (zext X) != 0 -> X != 0
1955 if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) {
1956 Instruction *LI = cast<CastInst>(LHS);
1957 Value *SrcOp = LI->getOperand(0);
1958 Type *SrcTy = SrcOp->getType();
1959 Type *DstTy = LI->getType();
1961 // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input
1962 // if the integer type is the same size as the pointer type.
1963 if (MaxRecurse && Q.TD && isa<PtrToIntInst>(LI) &&
1964 Q.TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) {
1965 if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
1966 // Transfer the cast to the constant.
1967 if (Value *V = SimplifyICmpInst(Pred, SrcOp,
1968 ConstantExpr::getIntToPtr(RHSC, SrcTy),
1971 } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) {
1972 if (RI->getOperand(0)->getType() == SrcTy)
1973 // Compare without the cast.
1974 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
1980 if (isa<ZExtInst>(LHS)) {
1981 // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the
1983 if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) {
1984 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
1985 // Compare X and Y. Note that signed predicates become unsigned.
1986 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
1987 SrcOp, RI->getOperand(0), Q,
1991 // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended
1992 // too. If not, then try to deduce the result of the comparison.
1993 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
1994 // Compute the constant that would happen if we truncated to SrcTy then
1995 // reextended to DstTy.
1996 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
1997 Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy);
1999 // If the re-extended constant didn't change then this is effectively
2000 // also a case of comparing two zero-extended values.
2001 if (RExt == CI && MaxRecurse)
2002 if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred),
2003 SrcOp, Trunc, Q, MaxRecurse-1))
2006 // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit
2007 // there. Use this to work out the result of the comparison.
2010 default: llvm_unreachable("Unknown ICmp predicate!");
2012 case ICmpInst::ICMP_EQ:
2013 case ICmpInst::ICMP_UGT:
2014 case ICmpInst::ICMP_UGE:
2015 return ConstantInt::getFalse(CI->getContext());
2017 case ICmpInst::ICMP_NE:
2018 case ICmpInst::ICMP_ULT:
2019 case ICmpInst::ICMP_ULE:
2020 return ConstantInt::getTrue(CI->getContext());
2022 // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS
2023 // is non-negative then LHS <s RHS.
2024 case ICmpInst::ICMP_SGT:
2025 case ICmpInst::ICMP_SGE:
2026 return CI->getValue().isNegative() ?
2027 ConstantInt::getTrue(CI->getContext()) :
2028 ConstantInt::getFalse(CI->getContext());
2030 case ICmpInst::ICMP_SLT:
2031 case ICmpInst::ICMP_SLE:
2032 return CI->getValue().isNegative() ?
2033 ConstantInt::getFalse(CI->getContext()) :
2034 ConstantInt::getTrue(CI->getContext());
2040 if (isa<SExtInst>(LHS)) {
2041 // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the
2043 if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) {
2044 if (MaxRecurse && SrcTy == RI->getOperand(0)->getType())
2045 // Compare X and Y. Note that the predicate does not change.
2046 if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0),
2050 // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended
2051 // too. If not, then try to deduce the result of the comparison.
2052 else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
2053 // Compute the constant that would happen if we truncated to SrcTy then
2054 // reextended to DstTy.
2055 Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy);
2056 Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy);
2058 // If the re-extended constant didn't change then this is effectively
2059 // also a case of comparing two sign-extended values.
2060 if (RExt == CI && MaxRecurse)
2061 if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1))
2064 // Otherwise the upper bits of LHS are all equal, while RHS has varying
2065 // bits there. Use this to work out the result of the comparison.
2068 default: llvm_unreachable("Unknown ICmp predicate!");
2069 case ICmpInst::ICMP_EQ:
2070 return ConstantInt::getFalse(CI->getContext());
2071 case ICmpInst::ICMP_NE:
2072 return ConstantInt::getTrue(CI->getContext());
2074 // If RHS is non-negative then LHS <s RHS. If RHS is negative then
2076 case ICmpInst::ICMP_SGT:
2077 case ICmpInst::ICMP_SGE:
2078 return CI->getValue().isNegative() ?
2079 ConstantInt::getTrue(CI->getContext()) :
2080 ConstantInt::getFalse(CI->getContext());
2081 case ICmpInst::ICMP_SLT:
2082 case ICmpInst::ICMP_SLE:
2083 return CI->getValue().isNegative() ?
2084 ConstantInt::getFalse(CI->getContext()) :
2085 ConstantInt::getTrue(CI->getContext());
2087 // If LHS is non-negative then LHS <u RHS. If LHS is negative then
2089 case ICmpInst::ICMP_UGT:
2090 case ICmpInst::ICMP_UGE:
2091 // Comparison is true iff the LHS <s 0.
2093 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp,
2094 Constant::getNullValue(SrcTy),
2098 case ICmpInst::ICMP_ULT:
2099 case ICmpInst::ICMP_ULE:
2100 // Comparison is true iff the LHS >=s 0.
2102 if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp,
2103 Constant::getNullValue(SrcTy),
2113 // Special logic for binary operators.
2114 BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS);
2115 BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS);
2116 if (MaxRecurse && (LBO || RBO)) {
2117 // Analyze the case when either LHS or RHS is an add instruction.
2118 Value *A = 0, *B = 0, *C = 0, *D = 0;
2119 // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null).
2120 bool NoLHSWrapProblem = false, NoRHSWrapProblem = false;
2121 if (LBO && LBO->getOpcode() == Instruction::Add) {
2122 A = LBO->getOperand(0); B = LBO->getOperand(1);
2123 NoLHSWrapProblem = ICmpInst::isEquality(Pred) ||
2124 (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) ||
2125 (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap());
2127 if (RBO && RBO->getOpcode() == Instruction::Add) {
2128 C = RBO->getOperand(0); D = RBO->getOperand(1);
2129 NoRHSWrapProblem = ICmpInst::isEquality(Pred) ||
2130 (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) ||
2131 (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap());
2134 // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow.
2135 if ((A == RHS || B == RHS) && NoLHSWrapProblem)
2136 if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A,
2137 Constant::getNullValue(RHS->getType()),
2141 // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow.
2142 if ((C == LHS || D == LHS) && NoRHSWrapProblem)
2143 if (Value *V = SimplifyICmpInst(Pred,
2144 Constant::getNullValue(LHS->getType()),
2145 C == LHS ? D : C, Q, MaxRecurse-1))
2148 // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow.
2149 if (A && C && (A == C || A == D || B == C || B == D) &&
2150 NoLHSWrapProblem && NoRHSWrapProblem) {
2151 // Determine Y and Z in the form icmp (X+Y), (X+Z).
2154 // C + B == C + D -> B == D
2157 } else if (A == D) {
2158 // D + B == C + D -> B == C
2161 } else if (B == C) {
2162 // A + C == C + D -> A == D
2167 // A + D == C + D -> A == C
2171 if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1))
2176 if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) {
2177 bool KnownNonNegative, KnownNegative;
2181 case ICmpInst::ICMP_SGT:
2182 case ICmpInst::ICMP_SGE:
2183 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
2184 if (!KnownNonNegative)
2187 case ICmpInst::ICMP_EQ:
2188 case ICmpInst::ICMP_UGT:
2189 case ICmpInst::ICMP_UGE:
2190 return getFalse(ITy);
2191 case ICmpInst::ICMP_SLT:
2192 case ICmpInst::ICMP_SLE:
2193 ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD);
2194 if (!KnownNonNegative)
2197 case ICmpInst::ICMP_NE:
2198 case ICmpInst::ICMP_ULT:
2199 case ICmpInst::ICMP_ULE:
2200 return getTrue(ITy);
2203 if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) {
2204 bool KnownNonNegative, KnownNegative;
2208 case ICmpInst::ICMP_SGT:
2209 case ICmpInst::ICMP_SGE:
2210 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
2211 if (!KnownNonNegative)
2214 case ICmpInst::ICMP_NE:
2215 case ICmpInst::ICMP_UGT:
2216 case ICmpInst::ICMP_UGE:
2217 return getTrue(ITy);
2218 case ICmpInst::ICMP_SLT:
2219 case ICmpInst::ICMP_SLE:
2220 ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD);
2221 if (!KnownNonNegative)
2224 case ICmpInst::ICMP_EQ:
2225 case ICmpInst::ICMP_ULT:
2226 case ICmpInst::ICMP_ULE:
2227 return getFalse(ITy);
2232 if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) {
2233 // icmp pred (X /u Y), X
2234 if (Pred == ICmpInst::ICMP_UGT)
2235 return getFalse(ITy);
2236 if (Pred == ICmpInst::ICMP_ULE)
2237 return getTrue(ITy);
2240 if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() &&
2241 LBO->getOperand(1) == RBO->getOperand(1)) {
2242 switch (LBO->getOpcode()) {
2244 case Instruction::UDiv:
2245 case Instruction::LShr:
2246 if (ICmpInst::isSigned(Pred))
2249 case Instruction::SDiv:
2250 case Instruction::AShr:
2251 if (!LBO->isExact() || !RBO->isExact())
2253 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2254 RBO->getOperand(0), Q, MaxRecurse-1))
2257 case Instruction::Shl: {
2258 bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap();
2259 bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap();
2262 if (!NSW && ICmpInst::isSigned(Pred))
2264 if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0),
2265 RBO->getOperand(0), Q, MaxRecurse-1))
2272 // Simplify comparisons involving max/min.
2274 CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE;
2275 CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B".
2277 // Signed variants on "max(a,b)>=a -> true".
2278 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2279 if (A != RHS) std::swap(A, B); // smax(A, B) pred A.
2280 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2281 // We analyze this as smax(A, B) pred A.
2283 } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) &&
2284 (A == LHS || B == LHS)) {
2285 if (A != LHS) std::swap(A, B); // A pred smax(A, B).
2286 EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B".
2287 // We analyze this as smax(A, B) swapped-pred A.
2288 P = CmpInst::getSwappedPredicate(Pred);
2289 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2290 (A == RHS || B == RHS)) {
2291 if (A != RHS) std::swap(A, B); // smin(A, B) pred A.
2292 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2293 // We analyze this as smax(-A, -B) swapped-pred -A.
2294 // Note that we do not need to actually form -A or -B thanks to EqP.
2295 P = CmpInst::getSwappedPredicate(Pred);
2296 } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) &&
2297 (A == LHS || B == LHS)) {
2298 if (A != LHS) std::swap(A, B); // A pred smin(A, B).
2299 EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B".
2300 // We analyze this as smax(-A, -B) pred -A.
2301 // Note that we do not need to actually form -A or -B thanks to EqP.
2304 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2305 // Cases correspond to "max(A, B) p A".
2309 case CmpInst::ICMP_EQ:
2310 case CmpInst::ICMP_SLE:
2311 // Equivalent to "A EqP B". This may be the same as the condition tested
2312 // in the max/min; if so, we can just return that.
2313 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2315 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2317 // Otherwise, see if "A EqP B" simplifies.
2319 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2322 case CmpInst::ICMP_NE:
2323 case CmpInst::ICMP_SGT: {
2324 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2325 // Equivalent to "A InvEqP B". This may be the same as the condition
2326 // tested in the max/min; if so, we can just return that.
2327 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2329 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2331 // Otherwise, see if "A InvEqP B" simplifies.
2333 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2337 case CmpInst::ICMP_SGE:
2339 return getTrue(ITy);
2340 case CmpInst::ICMP_SLT:
2342 return getFalse(ITy);
2346 // Unsigned variants on "max(a,b)>=a -> true".
2347 P = CmpInst::BAD_ICMP_PREDICATE;
2348 if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) {
2349 if (A != RHS) std::swap(A, B); // umax(A, B) pred A.
2350 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2351 // We analyze this as umax(A, B) pred A.
2353 } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) &&
2354 (A == LHS || B == LHS)) {
2355 if (A != LHS) std::swap(A, B); // A pred umax(A, B).
2356 EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B".
2357 // We analyze this as umax(A, B) swapped-pred A.
2358 P = CmpInst::getSwappedPredicate(Pred);
2359 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
2360 (A == RHS || B == RHS)) {
2361 if (A != RHS) std::swap(A, B); // umin(A, B) pred A.
2362 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2363 // We analyze this as umax(-A, -B) swapped-pred -A.
2364 // Note that we do not need to actually form -A or -B thanks to EqP.
2365 P = CmpInst::getSwappedPredicate(Pred);
2366 } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) &&
2367 (A == LHS || B == LHS)) {
2368 if (A != LHS) std::swap(A, B); // A pred umin(A, B).
2369 EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B".
2370 // We analyze this as umax(-A, -B) pred -A.
2371 // Note that we do not need to actually form -A or -B thanks to EqP.
2374 if (P != CmpInst::BAD_ICMP_PREDICATE) {
2375 // Cases correspond to "max(A, B) p A".
2379 case CmpInst::ICMP_EQ:
2380 case CmpInst::ICMP_ULE:
2381 // Equivalent to "A EqP B". This may be the same as the condition tested
2382 // in the max/min; if so, we can just return that.
2383 if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B))
2385 if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B))
2387 // Otherwise, see if "A EqP B" simplifies.
2389 if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1))
2392 case CmpInst::ICMP_NE:
2393 case CmpInst::ICMP_UGT: {
2394 CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP);
2395 // Equivalent to "A InvEqP B". This may be the same as the condition
2396 // tested in the max/min; if so, we can just return that.
2397 if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B))
2399 if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B))
2401 // Otherwise, see if "A InvEqP B" simplifies.
2403 if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1))
2407 case CmpInst::ICMP_UGE:
2409 return getTrue(ITy);
2410 case CmpInst::ICMP_ULT:
2412 return getFalse(ITy);
2416 // Variants on "max(x,y) >= min(x,z)".
2418 if (match(LHS, m_SMax(m_Value(A), m_Value(B))) &&
2419 match(RHS, m_SMin(m_Value(C), m_Value(D))) &&
2420 (A == C || A == D || B == C || B == D)) {
2421 // max(x, ?) pred min(x, ?).
2422 if (Pred == CmpInst::ICMP_SGE)
2424 return getTrue(ITy);
2425 if (Pred == CmpInst::ICMP_SLT)
2427 return getFalse(ITy);
2428 } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) &&
2429 match(RHS, m_SMax(m_Value(C), m_Value(D))) &&
2430 (A == C || A == D || B == C || B == D)) {
2431 // min(x, ?) pred max(x, ?).
2432 if (Pred == CmpInst::ICMP_SLE)
2434 return getTrue(ITy);
2435 if (Pred == CmpInst::ICMP_SGT)
2437 return getFalse(ITy);
2438 } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) &&
2439 match(RHS, m_UMin(m_Value(C), m_Value(D))) &&
2440 (A == C || A == D || B == C || B == D)) {
2441 // max(x, ?) pred min(x, ?).
2442 if (Pred == CmpInst::ICMP_UGE)
2444 return getTrue(ITy);
2445 if (Pred == CmpInst::ICMP_ULT)
2447 return getFalse(ITy);
2448 } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) &&
2449 match(RHS, m_UMax(m_Value(C), m_Value(D))) &&
2450 (A == C || A == D || B == C || B == D)) {
2451 // min(x, ?) pred max(x, ?).
2452 if (Pred == CmpInst::ICMP_ULE)
2454 return getTrue(ITy);
2455 if (Pred == CmpInst::ICMP_UGT)
2457 return getFalse(ITy);
2460 // Simplify comparisons of related pointers using a powerful, recursive
2461 // GEP-walk when we have target data available..
2462 if (Q.TD && LHS->getType()->isPointerTy())
2463 if (Constant *C = computePointerICmp(*Q.TD, Pred, LHS, RHS))
2466 if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) {
2467 if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) {
2468 if (GLHS->getPointerOperand() == GRHS->getPointerOperand() &&
2469 GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() &&
2470 (ICmpInst::isEquality(Pred) ||
2471 (GLHS->isInBounds() && GRHS->isInBounds() &&
2472 Pred == ICmpInst::getSignedPredicate(Pred)))) {
2473 // The bases are equal and the indices are constant. Build a constant
2474 // expression GEP with the same indices and a null base pointer to see
2475 // what constant folding can make out of it.
2476 Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType());
2477 SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end());
2478 Constant *NewLHS = ConstantExpr::getGetElementPtr(Null, IndicesLHS);
2480 SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end());
2481 Constant *NewRHS = ConstantExpr::getGetElementPtr(Null, IndicesRHS);
2482 return ConstantExpr::getICmp(Pred, NewLHS, NewRHS);
2487 // If the comparison is with the result of a select instruction, check whether
2488 // comparing with either branch of the select always yields the same value.
2489 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
2490 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
2493 // If the comparison is with the result of a phi instruction, check whether
2494 // doing the compare with each incoming phi value yields a common result.
2495 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
2496 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
2502 Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2503 const DataLayout *TD,
2504 const TargetLibraryInfo *TLI,
2505 const DominatorTree *DT) {
2506 return ::SimplifyICmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
2510 /// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
2511 /// fold the result. If not, this returns null.
2512 static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2513 const Query &Q, unsigned MaxRecurse) {
2514 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
2515 assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
2517 if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
2518 if (Constant *CRHS = dyn_cast<Constant>(RHS))
2519 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI);
2521 // If we have a constant, make sure it is on the RHS.
2522 std::swap(LHS, RHS);
2523 Pred = CmpInst::getSwappedPredicate(Pred);
2526 // Fold trivial predicates.
2527 if (Pred == FCmpInst::FCMP_FALSE)
2528 return ConstantInt::get(GetCompareTy(LHS), 0);
2529 if (Pred == FCmpInst::FCMP_TRUE)
2530 return ConstantInt::get(GetCompareTy(LHS), 1);
2532 if (isa<UndefValue>(RHS)) // fcmp pred X, undef -> undef
2533 return UndefValue::get(GetCompareTy(LHS));
2535 // fcmp x,x -> true/false. Not all compares are foldable.
2537 if (CmpInst::isTrueWhenEqual(Pred))
2538 return ConstantInt::get(GetCompareTy(LHS), 1);
2539 if (CmpInst::isFalseWhenEqual(Pred))
2540 return ConstantInt::get(GetCompareTy(LHS), 0);
2543 // Handle fcmp with constant RHS
2544 if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
2545 // If the constant is a nan, see if we can fold the comparison based on it.
2546 if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) {
2547 if (CFP->getValueAPF().isNaN()) {
2548 if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo"
2549 return ConstantInt::getFalse(CFP->getContext());
2550 assert(FCmpInst::isUnordered(Pred) &&
2551 "Comparison must be either ordered or unordered!");
2552 // True if unordered.
2553 return ConstantInt::getTrue(CFP->getContext());
2555 // Check whether the constant is an infinity.
2556 if (CFP->getValueAPF().isInfinity()) {
2557 if (CFP->getValueAPF().isNegative()) {
2559 case FCmpInst::FCMP_OLT:
2560 // No value is ordered and less than negative infinity.
2561 return ConstantInt::getFalse(CFP->getContext());
2562 case FCmpInst::FCMP_UGE:
2563 // All values are unordered with or at least negative infinity.
2564 return ConstantInt::getTrue(CFP->getContext());
2570 case FCmpInst::FCMP_OGT:
2571 // No value is ordered and greater than infinity.
2572 return ConstantInt::getFalse(CFP->getContext());
2573 case FCmpInst::FCMP_ULE:
2574 // All values are unordered with and at most infinity.
2575 return ConstantInt::getTrue(CFP->getContext());
2584 // If the comparison is with the result of a select instruction, check whether
2585 // comparing with either branch of the select always yields the same value.
2586 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
2587 if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse))
2590 // If the comparison is with the result of a phi instruction, check whether
2591 // doing the compare with each incoming phi value yields a common result.
2592 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
2593 if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse))
2599 Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2600 const DataLayout *TD,
2601 const TargetLibraryInfo *TLI,
2602 const DominatorTree *DT) {
2603 return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
2607 /// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
2608 /// the result. If not, this returns null.
2609 static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal,
2610 Value *FalseVal, const Query &Q,
2611 unsigned MaxRecurse) {
2612 // select true, X, Y -> X
2613 // select false, X, Y -> Y
2614 if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal))
2615 return CB->getZExtValue() ? TrueVal : FalseVal;
2617 // select C, X, X -> X
2618 if (TrueVal == FalseVal)
2621 if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
2622 if (isa<Constant>(TrueVal))
2626 if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
2628 if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
2634 Value *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
2635 const DataLayout *TD,
2636 const TargetLibraryInfo *TLI,
2637 const DominatorTree *DT) {
2638 return ::SimplifySelectInst(Cond, TrueVal, FalseVal, Query (TD, TLI, DT),
2642 /// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
2643 /// fold the result. If not, this returns null.
2644 static Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const Query &Q, unsigned) {
2645 // The type of the GEP pointer operand.
2646 PointerType *PtrTy = dyn_cast<PointerType>(Ops[0]->getType());
2647 // The GEP pointer operand is not a pointer, it's a vector of pointers.
2651 // getelementptr P -> P.
2652 if (Ops.size() == 1)
2655 if (isa<UndefValue>(Ops[0])) {
2656 // Compute the (pointer) type returned by the GEP instruction.
2657 Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1));
2658 Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace());
2659 return UndefValue::get(GEPTy);
2662 if (Ops.size() == 2) {
2663 // getelementptr P, 0 -> P.
2664 if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1]))
2667 // getelementptr P, N -> P if P points to a type of zero size.
2669 Type *Ty = PtrTy->getElementType();
2670 if (Ty->isSized() && Q.TD->getTypeAllocSize(Ty) == 0)
2675 // Check to see if this is constant foldable.
2676 for (unsigned i = 0, e = Ops.size(); i != e; ++i)
2677 if (!isa<Constant>(Ops[i]))
2680 return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), Ops.slice(1));
2683 Value *llvm::SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout *TD,
2684 const TargetLibraryInfo *TLI,
2685 const DominatorTree *DT) {
2686 return ::SimplifyGEPInst(Ops, Query (TD, TLI, DT), RecursionLimit);
2689 /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
2690 /// can fold the result. If not, this returns null.
2691 static Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
2692 ArrayRef<unsigned> Idxs, const Query &Q,
2694 if (Constant *CAgg = dyn_cast<Constant>(Agg))
2695 if (Constant *CVal = dyn_cast<Constant>(Val))
2696 return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs);
2698 // insertvalue x, undef, n -> x
2699 if (match(Val, m_Undef()))
2702 // insertvalue x, (extractvalue y, n), n
2703 if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val))
2704 if (EV->getAggregateOperand()->getType() == Agg->getType() &&
2705 EV->getIndices() == Idxs) {
2706 // insertvalue undef, (extractvalue y, n), n -> y
2707 if (match(Agg, m_Undef()))
2708 return EV->getAggregateOperand();
2710 // insertvalue y, (extractvalue y, n), n -> y
2711 if (Agg == EV->getAggregateOperand())
2718 Value *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val,
2719 ArrayRef<unsigned> Idxs,
2720 const DataLayout *TD,
2721 const TargetLibraryInfo *TLI,
2722 const DominatorTree *DT) {
2723 return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query (TD, TLI, DT),
2727 /// SimplifyPHINode - See if we can fold the given phi. If not, returns null.
2728 static Value *SimplifyPHINode(PHINode *PN, const Query &Q) {
2729 // If all of the PHI's incoming values are the same then replace the PHI node
2730 // with the common value.
2731 Value *CommonValue = 0;
2732 bool HasUndefInput = false;
2733 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
2734 Value *Incoming = PN->getIncomingValue(i);
2735 // If the incoming value is the phi node itself, it can safely be skipped.
2736 if (Incoming == PN) continue;
2737 if (isa<UndefValue>(Incoming)) {
2738 // Remember that we saw an undef value, but otherwise ignore them.
2739 HasUndefInput = true;
2742 if (CommonValue && Incoming != CommonValue)
2743 return 0; // Not the same, bail out.
2744 CommonValue = Incoming;
2747 // If CommonValue is null then all of the incoming values were either undef or
2748 // equal to the phi node itself.
2750 return UndefValue::get(PN->getType());
2752 // If we have a PHI node like phi(X, undef, X), where X is defined by some
2753 // instruction, we cannot return X as the result of the PHI node unless it
2754 // dominates the PHI block.
2756 return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : 0;
2761 static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
2762 if (Constant *C = dyn_cast<Constant>(Op))
2763 return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.TD, Q.TLI);
2768 Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *TD,
2769 const TargetLibraryInfo *TLI,
2770 const DominatorTree *DT) {
2771 return ::SimplifyTruncInst(Op, Ty, Query (TD, TLI, DT), RecursionLimit);
2774 //=== Helper functions for higher up the class hierarchy.
2776 /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
2777 /// fold the result. If not, this returns null.
2778 static Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
2779 const Query &Q, unsigned MaxRecurse) {
2781 case Instruction::Add:
2782 return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
2784 case Instruction::FAdd:
2785 return SimplifyFAddInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
2787 case Instruction::Sub:
2788 return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
2790 case Instruction::FSub:
2791 return SimplifyFSubInst(LHS, RHS, FastMathFlags(), Q, MaxRecurse);
2793 case Instruction::Mul: return SimplifyMulInst (LHS, RHS, Q, MaxRecurse);
2794 case Instruction::FMul:
2795 return SimplifyFMulInst (LHS, RHS, FastMathFlags(), Q, MaxRecurse);
2796 case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse);
2797 case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse);
2798 case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, Q, MaxRecurse);
2799 case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse);
2800 case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse);
2801 case Instruction::FRem: return SimplifyFRemInst(LHS, RHS, Q, MaxRecurse);
2802 case Instruction::Shl:
2803 return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false,
2805 case Instruction::LShr:
2806 return SimplifyLShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
2807 case Instruction::AShr:
2808 return SimplifyAShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse);
2809 case Instruction::And: return SimplifyAndInst(LHS, RHS, Q, MaxRecurse);
2810 case Instruction::Or: return SimplifyOrInst (LHS, RHS, Q, MaxRecurse);
2811 case Instruction::Xor: return SimplifyXorInst(LHS, RHS, Q, MaxRecurse);
2813 if (Constant *CLHS = dyn_cast<Constant>(LHS))
2814 if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
2815 Constant *COps[] = {CLHS, CRHS};
2816 return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.TD,
2820 // If the operation is associative, try some generic simplifications.
2821 if (Instruction::isAssociative(Opcode))
2822 if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse))
2825 // If the operation is with the result of a select instruction check whether
2826 // operating on either branch of the select always yields the same value.
2827 if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS))
2828 if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse))
2831 // If the operation is with the result of a phi instruction, check whether
2832 // operating on all incoming values of the phi always yields the same value.
2833 if (isa<PHINode>(LHS) || isa<PHINode>(RHS))
2834 if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse))
2841 Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
2842 const DataLayout *TD, const TargetLibraryInfo *TLI,
2843 const DominatorTree *DT) {
2844 return ::SimplifyBinOp(Opcode, LHS, RHS, Query (TD, TLI, DT), RecursionLimit);
2847 /// SimplifyCmpInst - Given operands for a CmpInst, see if we can
2848 /// fold the result.
2849 static Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2850 const Query &Q, unsigned MaxRecurse) {
2851 if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
2852 return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
2853 return SimplifyFCmpInst(Predicate, LHS, RHS, Q, MaxRecurse);
2856 Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
2857 const DataLayout *TD, const TargetLibraryInfo *TLI,
2858 const DominatorTree *DT) {
2859 return ::SimplifyCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT),
2863 template <typename IterTy>
2864 static Value *SimplifyCall(Value *V, IterTy ArgBegin, IterTy ArgEnd,
2865 const Query &Q, unsigned MaxRecurse) {
2866 Type *Ty = V->getType();
2867 if (PointerType *PTy = dyn_cast<PointerType>(Ty))
2868 Ty = PTy->getElementType();
2869 FunctionType *FTy = cast<FunctionType>(Ty);
2871 // call undef -> undef
2872 if (isa<UndefValue>(V))
2873 return UndefValue::get(FTy->getReturnType());
2875 Function *F = dyn_cast<Function>(V);
2879 if (!canConstantFoldCallTo(F))
2882 SmallVector<Constant *, 4> ConstantArgs;
2883 ConstantArgs.reserve(ArgEnd - ArgBegin);
2884 for (IterTy I = ArgBegin, E = ArgEnd; I != E; ++I) {
2885 Constant *C = dyn_cast<Constant>(*I);
2888 ConstantArgs.push_back(C);
2891 return ConstantFoldCall(F, ConstantArgs, Q.TLI);
2894 Value *llvm::SimplifyCall(Value *V, User::op_iterator ArgBegin,
2895 User::op_iterator ArgEnd, const DataLayout *TD,
2896 const TargetLibraryInfo *TLI,
2897 const DominatorTree *DT) {
2898 return ::SimplifyCall(V, ArgBegin, ArgEnd, Query(TD, TLI, DT),
2902 Value *llvm::SimplifyCall(Value *V, ArrayRef<Value *> Args,
2903 const DataLayout *TD, const TargetLibraryInfo *TLI,
2904 const DominatorTree *DT) {
2905 return ::SimplifyCall(V, Args.begin(), Args.end(), Query(TD, TLI, DT),
2909 /// SimplifyInstruction - See if we can compute a simplified version of this
2910 /// instruction. If not, this returns null.
2911 Value *llvm::SimplifyInstruction(Instruction *I, const DataLayout *TD,
2912 const TargetLibraryInfo *TLI,
2913 const DominatorTree *DT) {
2916 switch (I->getOpcode()) {
2918 Result = ConstantFoldInstruction(I, TD, TLI);
2920 case Instruction::FAdd:
2921 Result = SimplifyFAddInst(I->getOperand(0), I->getOperand(1),
2922 I->getFastMathFlags(), TD, TLI, DT);
2924 case Instruction::Add:
2925 Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1),
2926 cast<BinaryOperator>(I)->hasNoSignedWrap(),
2927 cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
2930 case Instruction::FSub:
2931 Result = SimplifyFSubInst(I->getOperand(0), I->getOperand(1),
2932 I->getFastMathFlags(), TD, TLI, DT);
2934 case Instruction::Sub:
2935 Result = SimplifySubInst(I->getOperand(0), I->getOperand(1),
2936 cast<BinaryOperator>(I)->hasNoSignedWrap(),
2937 cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
2940 case Instruction::FMul:
2941 Result = SimplifyFMulInst(I->getOperand(0), I->getOperand(1),
2942 I->getFastMathFlags(), TD, TLI, DT);
2944 case Instruction::Mul:
2945 Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2947 case Instruction::SDiv:
2948 Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2950 case Instruction::UDiv:
2951 Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2953 case Instruction::FDiv:
2954 Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2956 case Instruction::SRem:
2957 Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2959 case Instruction::URem:
2960 Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2962 case Instruction::FRem:
2963 Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2965 case Instruction::Shl:
2966 Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1),
2967 cast<BinaryOperator>(I)->hasNoSignedWrap(),
2968 cast<BinaryOperator>(I)->hasNoUnsignedWrap(),
2971 case Instruction::LShr:
2972 Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1),
2973 cast<BinaryOperator>(I)->isExact(),
2976 case Instruction::AShr:
2977 Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1),
2978 cast<BinaryOperator>(I)->isExact(),
2981 case Instruction::And:
2982 Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2984 case Instruction::Or:
2985 Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2987 case Instruction::Xor:
2988 Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2990 case Instruction::ICmp:
2991 Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(),
2992 I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2994 case Instruction::FCmp:
2995 Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
2996 I->getOperand(0), I->getOperand(1), TD, TLI, DT);
2998 case Instruction::Select:
2999 Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1),
3000 I->getOperand(2), TD, TLI, DT);
3002 case Instruction::GetElementPtr: {
3003 SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
3004 Result = SimplifyGEPInst(Ops, TD, TLI, DT);
3007 case Instruction::InsertValue: {
3008 InsertValueInst *IV = cast<InsertValueInst>(I);
3009 Result = SimplifyInsertValueInst(IV->getAggregateOperand(),
3010 IV->getInsertedValueOperand(),
3011 IV->getIndices(), TD, TLI, DT);
3014 case Instruction::PHI:
3015 Result = SimplifyPHINode(cast<PHINode>(I), Query (TD, TLI, DT));
3017 case Instruction::Call: {
3018 CallSite CS(cast<CallInst>(I));
3019 Result = SimplifyCall(CS.getCalledValue(), CS.arg_begin(), CS.arg_end(),
3023 case Instruction::Trunc:
3024 Result = SimplifyTruncInst(I->getOperand(0), I->getType(), TD, TLI, DT);
3028 /// If called on unreachable code, the above logic may report that the
3029 /// instruction simplified to itself. Make life easier for users by
3030 /// detecting that case here, returning a safe value instead.
3031 return Result == I ? UndefValue::get(I->getType()) : Result;
3034 /// \brief Implementation of recursive simplification through an instructions
3037 /// This is the common implementation of the recursive simplification routines.
3038 /// If we have a pre-simplified value in 'SimpleV', that is forcibly used to
3039 /// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of
3040 /// instructions to process and attempt to simplify it using
3041 /// InstructionSimplify.
3043 /// This routine returns 'true' only when *it* simplifies something. The passed
3044 /// in simplified value does not count toward this.
3045 static bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV,
3046 const DataLayout *TD,
3047 const TargetLibraryInfo *TLI,
3048 const DominatorTree *DT) {
3049 bool Simplified = false;
3050 SmallSetVector<Instruction *, 8> Worklist;
3052 // If we have an explicit value to collapse to, do that round of the
3053 // simplification loop by hand initially.
3055 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
3058 Worklist.insert(cast<Instruction>(*UI));
3060 // Replace the instruction with its simplified value.
3061 I->replaceAllUsesWith(SimpleV);
3063 // Gracefully handle edge cases where the instruction is not wired into any
3066 I->eraseFromParent();
3071 // Note that we must test the size on each iteration, the worklist can grow.
3072 for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) {
3075 // See if this instruction simplifies.
3076 SimpleV = SimplifyInstruction(I, TD, TLI, DT);
3082 // Stash away all the uses of the old instruction so we can check them for
3083 // recursive simplifications after a RAUW. This is cheaper than checking all
3084 // uses of To on the recursive step in most cases.
3085 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE;
3087 Worklist.insert(cast<Instruction>(*UI));
3089 // Replace the instruction with its simplified value.
3090 I->replaceAllUsesWith(SimpleV);
3092 // Gracefully handle edge cases where the instruction is not wired into any
3095 I->eraseFromParent();
3100 bool llvm::recursivelySimplifyInstruction(Instruction *I,
3101 const DataLayout *TD,
3102 const TargetLibraryInfo *TLI,
3103 const DominatorTree *DT) {
3104 return replaceAndRecursivelySimplifyImpl(I, 0, TD, TLI, DT);
3107 bool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
3108 const DataLayout *TD,
3109 const TargetLibraryInfo *TLI,
3110 const DominatorTree *DT) {
3111 assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!");
3112 assert(SimpleV && "Must provide a simplified value.");
3113 return replaceAndRecursivelySimplifyImpl(I, SimpleV, TD, TLI, DT);