llvm-6502/include/llvm/Transforms/Utils/SimplifyLibCalls.h
Sanjay Patel dc18ebc4b1 Shrinkify libcalls: use float versions of double libm functions with fast-math (bug 17850)
When a call to a double-precision libm function has fast-math semantics 
(via function attribute for now because there is no IR-level FMF on calls), 
we can avoid fpext/fptrunc operations and use the float version of the call
if the input and output are both float.

We already do this optimization using a command-line option; this patch just
adds the ability for fast-math to use the existing functionality.

I moved the cl::opt from InstructionCombining into SimplifyLibCalls because
it's only ever used internally to that class.

Modified the existing test cases to use the unsafe-fp-math attribute rather
than repeating all tests.

This patch should solve: http://llvm.org/bugs/show_bug.cgi?id=17850

Differential Revision: http://reviews.llvm.org/D5893



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220390 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 15:29:23 +00:00

133 lines
5.5 KiB
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//===- SimplifyLibCalls.h - Library call simplifier -------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file exposes an interface to build some C language libcalls for
// optimization passes that need to call the various functions.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_UTILS_SIMPLIFYLIBCALLS_H
#define LLVM_TRANSFORMS_UTILS_SIMPLIFYLIBCALLS_H
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/IRBuilder.h"
namespace llvm {
class Value;
class CallInst;
class DataLayout;
class Instruction;
class TargetLibraryInfo;
class BasicBlock;
class Function;
/// LibCallSimplifier - This class implements a collection of optimizations
/// that replace well formed calls to library functions with a more optimal
/// form. For example, replacing 'printf("Hello!")' with 'puts("Hello!")'.
class LibCallSimplifier {
private:
const DataLayout *DL;
const TargetLibraryInfo *TLI;
bool UnsafeFPShrink;
protected:
~LibCallSimplifier() {}
public:
LibCallSimplifier(const DataLayout *TD, const TargetLibraryInfo *TLI);
/// optimizeCall - Take the given call instruction and return a more
/// optimal value to replace the instruction with or 0 if a more
/// optimal form can't be found. Note that the returned value may
/// be equal to the instruction being optimized. In this case all
/// other instructions that use the given instruction were modified
/// and the given instruction is dead.
Value *optimizeCall(CallInst *CI);
/// replaceAllUsesWith - This method is used when the library call
/// simplifier needs to replace instructions other than the library
/// call being modified.
virtual void replaceAllUsesWith(Instruction *I, Value *With) const;
private:
// Fortified Library Call Optimizations
Value *optimizeMemCpyChk(CallInst *CI, IRBuilder<> &B);
Value *optimizeMemMoveChk(CallInst *CI, IRBuilder<> &B);
Value *optimizeMemSetChk(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrCpyChk(CallInst *CI, IRBuilder<> &B);
Value *optimizeStpCpyChk(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrNCpyChk(CallInst *CI, IRBuilder<> &B);
// String and Memory Library Call Optimizations
Value *optimizeStrCat(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrNCat(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrChr(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrRChr(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrCmp(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrNCmp(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrCpy(CallInst *CI, IRBuilder<> &B);
Value *optimizeStpCpy(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrNCpy(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrLen(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrPBrk(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrTo(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrSpn(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrCSpn(CallInst *CI, IRBuilder<> &B);
Value *optimizeStrStr(CallInst *CI, IRBuilder<> &B);
Value *optimizeMemCmp(CallInst *CI, IRBuilder<> &B);
Value *optimizeMemCpy(CallInst *CI, IRBuilder<> &B);
Value *optimizeMemMove(CallInst *CI, IRBuilder<> &B);
Value *optimizeMemSet(CallInst *CI, IRBuilder<> &B);
// Math Library Optimizations
Value *optimizeUnaryDoubleFP(CallInst *CI, IRBuilder<> &B, bool CheckRetType);
Value *optimizeBinaryDoubleFP(CallInst *CI, IRBuilder<> &B);
Value *optimizeCos(CallInst *CI, IRBuilder<> &B);
Value *optimizePow(CallInst *CI, IRBuilder<> &B);
Value *optimizeExp2(CallInst *CI, IRBuilder<> &B);
Value *optimizeFabs(CallInst *CI, IRBuilder<> &B);
Value *optimizeSqrt(CallInst *CI, IRBuilder<> &B);
Value *optimizeSinCosPi(CallInst *CI, IRBuilder<> &B);
// Integer Library Call Optimizations
Value *optimizeFFS(CallInst *CI, IRBuilder<> &B);
Value *optimizeAbs(CallInst *CI, IRBuilder<> &B);
Value *optimizeIsDigit(CallInst *CI, IRBuilder<> &B);
Value *optimizeIsAscii(CallInst *CI, IRBuilder<> &B);
Value *optimizeToAscii(CallInst *CI, IRBuilder<> &B);
// Formatting and IO Library Call Optimizations
Value *optimizeErrorReporting(CallInst *CI, IRBuilder<> &B,
int StreamArg = -1);
Value *optimizePrintF(CallInst *CI, IRBuilder<> &B);
Value *optimizeSPrintF(CallInst *CI, IRBuilder<> &B);
Value *optimizeFPrintF(CallInst *CI, IRBuilder<> &B);
Value *optimizeFWrite(CallInst *CI, IRBuilder<> &B);
Value *optimizeFPuts(CallInst *CI, IRBuilder<> &B);
Value *optimizePuts(CallInst *CI, IRBuilder<> &B);
// Helper methods
Value *emitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len, IRBuilder<> &B);
void classifyArgUse(Value *Val, BasicBlock *BB, bool IsFloat,
SmallVectorImpl<CallInst *> &SinCalls,
SmallVectorImpl<CallInst *> &CosCalls,
SmallVectorImpl<CallInst *> &SinCosCalls);
void replaceTrigInsts(SmallVectorImpl<CallInst *> &Calls, Value *Res);
Value *optimizePrintFString(CallInst *CI, IRBuilder<> &B);
Value *optimizeSPrintFString(CallInst *CI, IRBuilder<> &B);
Value *optimizeFPrintFString(CallInst *CI, IRBuilder<> &B);
/// hasFloatVersion - Checks if there is a float version of the specified
/// function by checking for an existing function with name FuncName + f
bool hasFloatVersion(StringRef FuncName);
};
} // End llvm namespace
#endif