llvm-6502/include/llvm/Analysis/InstructionSimplify.h
Chandler Carruth e949aa1c91 Teach instsimplify to use the constant folder where appropriate for
constant folding calls. Add the initial tests for this which show that
now instsimplify can simplify blindingly obvious code patterns expressed
with both intrinsics and library calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171194 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-28 14:23:29 +00:00

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//===-- 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. This does constant folding
// ("add i32 1, 1" -> "2") but can also handle non-constant operands, either
// returning a constant ("and i32 %x, 0" -> "0") or an already existing value
// ("and i32 %x, %x" -> "%x"). If the simplification is also an instruction
// then it dominates the original instruction.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
#include "llvm/User.h"
namespace llvm {
template<typename T>
class ArrayRef;
class DominatorTree;
class Instruction;
class DataLayout;
class FastMathFlags;
class TargetLibraryInfo;
class Type;
class Value;
/// SimplifyAddInst - Given operands for an Add, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifySubInst - Given operands for a Sub, see if we can
/// fold the result. If not, this returns null.
Value *SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// Given operands for an FAdd, see if we can fold the result. If not, this
/// returns null.
Value *SimplifyFAddInst(Value *LHS, Value *RHS, FastMathFlags FMF,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// Given operands for an FSub, see if we can fold the result. If not, this
/// returns null.
Value *SimplifyFSubInst(Value *LHS, Value *RHS, FastMathFlags FMF,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// Given operands for an FMul, see if we can fold the result. If not, this
/// returns null.
Value *SimplifyFMulInst(Value *LHS, Value *RHS,
FastMathFlags FMF,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyMulInst - Given operands for a Mul, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyMulInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifySDivInst - Given operands for an SDiv, see if we can
/// fold the result. If not, this returns null.
Value *SimplifySDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyUDivInst - Given operands for a UDiv, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyUDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyFDivInst - Given operands for an FDiv, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyFDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifySRemInst - Given operands for an SRem, see if we can
/// fold the result. If not, this returns null.
Value *SimplifySRemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyURemInst - Given operands for a URem, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyURemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyFRemInst - Given operands for an FRem, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyFRemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyShlInst - Given operands for a Shl, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyLShrInst - Given operands for a LShr, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyAShrInst - Given operands for a AShr, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyAndInst - Given operands for an And, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyAndInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyOrInst - Given operands for an Or, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyOrInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyXorInst - Given operands for a Xor, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyXorInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
/// the result. If not, this returns null.
Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
/// can fold the result. If not, this returns null.
Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
ArrayRef<unsigned> Idxs,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyTruncInst - Given operands for an TruncInst, see if we can fold
/// the result. If not, this returns null.
Value *SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
//=== Helper functions for higher up the class hierarchy.
/// SimplifyCmpInst - Given operands for a CmpInst, see if we can
/// fold the result. If not, this returns null.
Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 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 DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// \brief Given a function and iterators over arguments, see if we can fold
/// the result.
///
/// If this call could not be simplified returns null.
Value *SimplifyCall(Value *V, User::op_iterator ArgBegin,
User::op_iterator ArgEnd, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// \brief Given a function and set of arguments, see if we can fold the
/// result.
///
/// If this call could not be simplified returns null.
Value *SimplifyCall(Value *V, ArrayRef<Value *> Args,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// SimplifyInstruction - See if we can compute a simplified version of this
/// instruction. If not, this returns null.
Value *SimplifyInstruction(Instruction *I, const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// \brief Replace all uses of 'I' with 'SimpleV' and simplify the uses
/// recursively.
///
/// This first performs a normal RAUW of I with SimpleV. It then recursively
/// attempts to simplify those users updated by the operation. The 'I'
/// instruction must not be equal to the simplified value 'SimpleV'.
///
/// The function returns true if any simplifications were performed.
bool replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
/// \brief Recursively attempt to simplify an instruction.
///
/// This routine uses SimplifyInstruction to simplify 'I', and if successful
/// replaces uses of 'I' with the simplified value. It then recurses on each
/// of the users impacted. It returns true if any simplifications were
/// performed.
bool recursivelySimplifyInstruction(Instruction *I,
const DataLayout *TD = 0,
const TargetLibraryInfo *TLI = 0,
const DominatorTree *DT = 0);
} // end namespace llvm
#endif