diff --git a/include/llvm/Analysis/InstructionSimplify.h b/include/llvm/Analysis/InstructionSimplify.h new file mode 100644 index 00000000000..7d754355754 --- /dev/null +++ b/include/llvm/Analysis/InstructionSimplify.h @@ -0,0 +1,37 @@ +//===-- InstructionSimplify.h - Fold instructions into simpler forms ------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file declares routines for folding instructions into simpler forms that +// do not require creating new instructions. For example, this does constant +// folding, and can handle identities like (X&0)->0. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H +#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H + +namespace llvm { + class Value; + class TargetData; + + /// SimplifyCompare - Given operands for a CmpInst, see if we can + /// fold the result. If not, this returns null. + Value *SimplifyCompare(unsigned Predicate, Value *LHS, Value *RHS, + const TargetData *TD = 0); + + + /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can + /// fold the result. If not, this returns null. + Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, + const TargetData *TD = 0); + +} // end namespace llvm + +#endif + diff --git a/lib/Analysis/CMakeLists.txt b/lib/Analysis/CMakeLists.txt index f21fd54596d..3f8356caf0a 100644 --- a/lib/Analysis/CMakeLists.txt +++ b/lib/Analysis/CMakeLists.txt @@ -15,6 +15,7 @@ add_llvm_library(LLVMAnalysis IVUsers.cpp InlineCost.cpp InstCount.cpp + InstructionSimplify.cpp Interval.cpp IntervalPartition.cpp LibCallAliasAnalysis.cpp diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp new file mode 100644 index 00000000000..692236a0f22 --- /dev/null +++ b/lib/Analysis/InstructionSimplify.cpp @@ -0,0 +1,57 @@ +//===- InstructionSimplify.cpp - Fold instruction operands ----------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements routines for folding instructions into simpler forms +// that do not require creating new instructions. For example, this does +// constant folding, and can handle identities like (X&0)->0. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Analysis/InstructionSimplify.h" +#include "llvm/Analysis/ConstantFolding.h" +#include "llvm/Instructions.h" +using namespace llvm; + + +/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can +/// fold the result. If not, this returns null. +Value *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, + const TargetData *TD) { + if (Constant *CLHS = dyn_cast(LHS)) + if (Constant *CRHS = dyn_cast(RHS)) { + Constant *COps[] = {CLHS, CRHS}; + return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD); + } + return 0; +} + + +/// SimplifyCompare - Given operands for a CmpInst, see if we can +/// fold the result. +Value *llvm::SimplifyCompare(unsigned Predicate, Value *LHS, Value *RHS, + const TargetData *TD) { + CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate; + + if (Constant *CLHS = dyn_cast(LHS)) + if (Constant *CRHS = dyn_cast(RHS)) { + Constant *COps[] = {CLHS, CRHS}; + return ConstantFoldCompareInstOperands(Pred, COps, 2, TD); + } + + // If this is an integer compare and the LHS and RHS are the same, fold it. + if (LHS == RHS) + if (isa(LHS->getType()) || isa(LHS->getType())) { + if (ICmpInst::isTrueWhenEqual(Pred)) + return ConstantInt::getTrue(LHS->getContext()); + else + return ConstantInt::getFalse(LHS->getContext()); + } + return 0; +} +