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. For example, this does
12 // constant folding, and can handle identities like (X&0)->0.
14 //===----------------------------------------------------------------------===//
16 #include "llvm/Analysis/InstructionSimplify.h"
17 #include "llvm/Analysis/ConstantFolding.h"
18 #include "llvm/Instructions.h"
22 /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
23 /// fold the result. If not, this returns null.
24 Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
25 const TargetData *TD) {
26 if (Constant *CLHS = dyn_cast<Constant>(LHS))
27 if (Constant *CRHS = dyn_cast<Constant>(RHS)) {
28 Constant *COps[] = {CLHS, CRHS};
29 return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD);
35 /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
36 /// fold the result. If not, this returns null.
37 Value *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
38 const TargetData *TD) {
39 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
40 assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!");
42 if (Constant *CLHS = dyn_cast<Constant>(LHS))
43 if (Constant *CRHS = dyn_cast<Constant>(RHS))
44 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
46 // If this is an integer compare and the LHS and RHS are the same, fold it.
48 if (ICmpInst::isTrueWhenEqual(Pred))
49 return ConstantInt::getTrue(LHS->getContext());
51 return ConstantInt::getFalse(LHS->getContext());
56 /// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
57 /// fold the result. If not, this returns null.
58 Value *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
59 const TargetData *TD) {
60 CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate;
61 assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!");
63 if (Constant *CLHS = dyn_cast<Constant>(LHS))
64 if (Constant *CRHS = dyn_cast<Constant>(RHS))
65 return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD);
72 /// SimplifyCmpInst - Given operands for a CmpInst, see if we can
74 Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
75 const TargetData *TD) {
76 if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate))
77 return SimplifyICmpInst(Predicate, LHS, RHS, TD);
78 return SimplifyFCmpInst(Predicate, LHS, RHS, TD);