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//===- SimplifyLibCalls.cpp - Optimize specific well-known library calls --===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file implements a simple pass that applies a variety of small
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// optimizations for calls to specific well-known function calls (e.g. runtime
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// library functions). Any optimization that takes the very simple form
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// "replace call to library function with simpler code that provides the same
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// result" belongs in this file.
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "simplify-libcalls"
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#include "llvm/Transforms/Scalar.h"
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#include "llvm/Transforms/Utils/BuildLibCalls.h"
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#include "llvm/Intrinsics.h"
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#include "llvm/LLVMContext.h"
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#include "llvm/Module.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/IRBuilder.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/StringMap.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Config/config.h"
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STATISTIC(NumSimplified, "Number of library calls simplified");
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STATISTIC(NumAnnotated, "Number of attributes added to library functions");
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//===----------------------------------------------------------------------===//
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// Optimizer Base Class
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//===----------------------------------------------------------------------===//
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/// This class is the abstract base class for the set of optimizations that
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/// corresponds to one library call.
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class LibCallOptimization {
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LibCallOptimization() { }
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virtual ~LibCallOptimization() {}
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/// CallOptimizer - This pure virtual method is implemented by base classes to
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/// do various optimizations. If this returns null then no transformation was
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/// performed. If it returns CI, then it transformed the call and CI is to be
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/// deleted. If it returns something else, replace CI with the new value and
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B)
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Value *OptimizeCall(CallInst *CI, const TargetData *TD, IRBuilder<> &B) {
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Caller = CI->getParent()->getParent();
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if (CI->getCalledFunction())
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Context = &CI->getCalledFunction()->getContext();
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// We never change the calling convention.
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if (CI->getCallingConv() != llvm::CallingConv::C)
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return CallOptimizer(CI->getCalledFunction(), CI, B);
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} // End anonymous namespace.
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//===----------------------------------------------------------------------===//
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//===----------------------------------------------------------------------===//
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/// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
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/// value is equal or not-equal to zero.
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static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
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for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
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if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
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if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
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// Unknown instruction.
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/// IsOnlyUsedInEqualityComparison - Return true if it is only used in equality
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/// comparisons with With.
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static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) {
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for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
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if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
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if (IC->isEquality() && IC->getOperand(1) == With)
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// Unknown instruction.
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//===----------------------------------------------------------------------===//
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// String and Memory LibCall Optimizations
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//===----------------------------------------------------------------------===//
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//===---------------------------------------===//
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// 'strcat' Optimizations
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struct StrCatOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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// Verify the "strcat" function prototype.
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 2 ||
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FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
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FT->getParamType(0) != FT->getReturnType() ||
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FT->getParamType(1) != FT->getReturnType())
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// Extract some information from the instruction
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Value *Dst = CI->getArgOperand(0);
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Value *Src = CI->getArgOperand(1);
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// See if we can get the length of the input string.
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uint64_t Len = GetStringLength(Src);
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if (Len == 0) return 0;
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--Len; // Unbias length.
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// Handle the simple, do-nothing case: strcat(x, "") -> x
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// These optimizations require TargetData.
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EmitStrLenMemCpy(Src, Dst, Len, B);
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void EmitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len, IRBuilder<> &B) {
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// We need to find the end of the destination string. That's where the
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// memory is to be moved to. We just generate a call to strlen.
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Value *DstLen = EmitStrLen(Dst, B, TD);
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// Now that we have the destination's length, we must index into the
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// destination's pointer to get the actual memcpy destination (end of
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// the string .. we're concatenating).
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Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
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// We have enough information to now generate the memcpy call to do the
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// concatenation for us. Make a memcpy to copy the nul byte with align = 1.
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EmitMemCpy(CpyDst, Src,
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ConstantInt::get(TD->getIntPtrType(*Context), Len+1),
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//===---------------------------------------===//
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// 'strncat' Optimizations
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struct StrNCatOpt : public StrCatOpt {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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// Verify the "strncat" function prototype.
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 3 ||
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FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
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FT->getParamType(0) != FT->getReturnType() ||
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FT->getParamType(1) != FT->getReturnType() ||
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!FT->getParamType(2)->isIntegerTy())
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// Extract some information from the instruction
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Value *Dst = CI->getArgOperand(0);
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Value *Src = CI->getArgOperand(1);
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// We don't do anything if length is not constant
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if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
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Len = LengthArg->getZExtValue();
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// See if we can get the length of the input string.
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uint64_t SrcLen = GetStringLength(Src);
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if (SrcLen == 0) return 0;
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--SrcLen; // Unbias length.
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// Handle the simple, do-nothing cases:
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// strncat(x, "", c) -> x
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// strncat(x, c, 0) -> x
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if (SrcLen == 0 || Len == 0) return Dst;
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// These optimizations require TargetData.
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// We don't optimize this case
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if (Len < SrcLen) return 0;
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// strncat(x, s, c) -> strcat(x, s)
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// s is constant so the strcat can be optimized further
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EmitStrLenMemCpy(Src, Dst, SrcLen, B);
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//===---------------------------------------===//
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// 'strchr' Optimizations
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struct StrChrOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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// Verify the "strchr" function prototype.
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 2 ||
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FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
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FT->getParamType(0) != FT->getReturnType())
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Value *SrcStr = CI->getArgOperand(0);
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// If the second operand is non-constant, see if we can compute the length
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// of the input string and turn this into memchr.
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ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
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// These optimizations require TargetData.
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uint64_t Len = GetStringLength(SrcStr);
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if (Len == 0 || !FT->getParamType(1)->isIntegerTy(32))// memchr needs i32.
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return EmitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
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ConstantInt::get(TD->getIntPtrType(*Context), Len),
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// Otherwise, the character is a constant, see if the first argument is
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// a string literal. If so, we can constant fold.
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if (!GetConstantStringInfo(SrcStr, Str))
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// strchr can find the nul character.
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char CharValue = CharC->getSExtValue();
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// Compute the offset.
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if (i == Str.size()) // Didn't find the char. strchr returns null.
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return Constant::getNullValue(CI->getType());
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// Did we find our match?
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if (Str[i] == CharValue)
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// strchr(s+n,c) -> gep(s+n+i,c)
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Value *Idx = ConstantInt::get(Type::getInt64Ty(*Context), i);
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return B.CreateGEP(SrcStr, Idx, "strchr");
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//===---------------------------------------===//
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// 'strcmp' Optimizations
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struct StrCmpOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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// Verify the "strcmp" function prototype.
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 2 ||
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!FT->getReturnType()->isIntegerTy(32) ||
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FT->getParamType(0) != FT->getParamType(1) ||
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FT->getParamType(0) != Type::getInt8PtrTy(*Context))
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Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
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if (Str1P == Str2P) // strcmp(x,x) -> 0
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return ConstantInt::get(CI->getType(), 0);
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std::string Str1, Str2;
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bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
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bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
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if (HasStr1 && Str1.empty()) // strcmp("", x) -> *x
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return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
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if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
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return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
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// strcmp(x, y) -> cnst (if both x and y are constant strings)
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if (HasStr1 && HasStr2)
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return ConstantInt::get(CI->getType(),
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strcmp(Str1.c_str(),Str2.c_str()));
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// strcmp(P, "x") -> memcmp(P, "x", 2)
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uint64_t Len1 = GetStringLength(Str1P);
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uint64_t Len2 = GetStringLength(Str2P);
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// These optimizations require TargetData.
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return EmitMemCmp(Str1P, Str2P,
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ConstantInt::get(TD->getIntPtrType(*Context),
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std::min(Len1, Len2)), B, TD);
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//===---------------------------------------===//
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// 'strncmp' Optimizations
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struct StrNCmpOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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// Verify the "strncmp" function prototype.
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 3 ||
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!FT->getReturnType()->isIntegerTy(32) ||
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FT->getParamType(0) != FT->getParamType(1) ||
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FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
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!FT->getParamType(2)->isIntegerTy())
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Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
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if (Str1P == Str2P) // strncmp(x,x,n) -> 0
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return ConstantInt::get(CI->getType(), 0);
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// Get the length argument if it is constant.
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if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
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Length = LengthArg->getZExtValue();
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if (Length == 0) // strncmp(x,y,0) -> 0
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return ConstantInt::get(CI->getType(), 0);
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if (TD && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
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return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, TD);
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std::string Str1, Str2;
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bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
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bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
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if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> *x
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return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
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if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
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return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
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// strncmp(x, y) -> cnst (if both x and y are constant strings)
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if (HasStr1 && HasStr2)
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return ConstantInt::get(CI->getType(),
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strncmp(Str1.c_str(), Str2.c_str(), Length));
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//===---------------------------------------===//
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// 'strcpy' Optimizations
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struct StrCpyOpt : public LibCallOptimization {
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bool OptChkCall; // True if it's optimizing a __strcpy_chk libcall.
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StrCpyOpt(bool c) : OptChkCall(c) {}
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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// Verify the "strcpy" function prototype.
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unsigned NumParams = OptChkCall ? 3 : 2;
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != NumParams ||
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FT->getReturnType() != FT->getParamType(0) ||
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FT->getParamType(0) != FT->getParamType(1) ||
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FT->getParamType(0) != Type::getInt8PtrTy(*Context))
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Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
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if (Dst == Src) // strcpy(x,x) -> x
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// These optimizations require TargetData.
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// See if we can get the length of the input string.
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uint64_t Len = GetStringLength(Src);
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if (Len == 0) return 0;
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// We have enough information to now generate the memcpy call to do the
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// concatenation for us. Make a memcpy to copy the nul byte with align = 1.
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EmitMemCpyChk(Dst, Src,
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ConstantInt::get(TD->getIntPtrType(*Context), Len),
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CI->getArgOperand(2), B, TD);
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ConstantInt::get(TD->getIntPtrType(*Context), Len),
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//===---------------------------------------===//
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// 'strncpy' Optimizations
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struct StrNCpyOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
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FT->getParamType(0) != FT->getParamType(1) ||
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FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
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!FT->getParamType(2)->isIntegerTy())
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Value *Dst = CI->getArgOperand(0);
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Value *Src = CI->getArgOperand(1);
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Value *LenOp = CI->getArgOperand(2);
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// See if we can get the length of the input string.
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uint64_t SrcLen = GetStringLength(Src);
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if (SrcLen == 0) return 0;
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// strncpy(x, "", y) -> memset(x, '\0', y, 1)
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EmitMemSet(Dst, ConstantInt::get(Type::getInt8Ty(*Context), '\0'),
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LenOp, false, B, TD);
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if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
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Len = LengthArg->getZExtValue();
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if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
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// These optimizations require TargetData.
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// Let strncpy handle the zero padding
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if (Len > SrcLen+1) return 0;
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// strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
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ConstantInt::get(TD->getIntPtrType(*Context), Len),
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//===---------------------------------------===//
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// 'strlen' Optimizations
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struct StrLenOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 1 ||
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FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
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!FT->getReturnType()->isIntegerTy())
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Value *Src = CI->getArgOperand(0);
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// Constant folding: strlen("xyz") -> 3
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if (uint64_t Len = GetStringLength(Src))
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return ConstantInt::get(CI->getType(), Len-1);
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// strlen(x) != 0 --> *x != 0
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// strlen(x) == 0 --> *x == 0
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if (IsOnlyUsedInZeroEqualityComparison(CI))
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return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
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//===---------------------------------------===//
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// 'strto*' Optimizations. This handles strtol, strtod, strtof, strtoul, etc.
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struct StrToOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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const FunctionType *FT = Callee->getFunctionType();
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if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
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!FT->getParamType(0)->isPointerTy() ||
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!FT->getParamType(1)->isPointerTy())
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Value *EndPtr = CI->getArgOperand(1);
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if (isa<ConstantPointerNull>(EndPtr)) {
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CI->setOnlyReadsMemory();
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CI->addAttribute(1, Attribute::NoCapture);
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//===---------------------------------------===//
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// 'strstr' Optimizations
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struct StrStrOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 2 ||
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!FT->getParamType(0)->isPointerTy() ||
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!FT->getParamType(1)->isPointerTy() ||
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!FT->getReturnType()->isPointerTy())
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// fold strstr(x, x) -> x.
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if (CI->getArgOperand(0) == CI->getArgOperand(1))
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return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
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// fold strstr(a, b) == a -> strncmp(a, b, strlen(b)) == 0
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if (TD && IsOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
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Value *StrLen = EmitStrLen(CI->getArgOperand(1), B, TD);
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Value *StrNCmp = EmitStrNCmp(CI->getArgOperand(0), CI->getArgOperand(1),
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for (Value::use_iterator UI = CI->use_begin(), UE = CI->use_end();
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ICmpInst *Old = cast<ICmpInst>(*UI++);
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Value *Cmp = B.CreateICmp(Old->getPredicate(), StrNCmp,
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ConstantInt::getNullValue(StrNCmp->getType()),
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Old->replaceAllUsesWith(Cmp);
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Old->eraseFromParent();
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// See if either input string is a constant string.
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std::string SearchStr, ToFindStr;
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bool HasStr1 = GetConstantStringInfo(CI->getArgOperand(0), SearchStr);
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bool HasStr2 = GetConstantStringInfo(CI->getArgOperand(1), ToFindStr);
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// fold strstr(x, "") -> x.
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if (HasStr2 && ToFindStr.empty())
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return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
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// If both strings are known, constant fold it.
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if (HasStr1 && HasStr2) {
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std::string::size_type Offset = SearchStr.find(ToFindStr);
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if (Offset == std::string::npos) // strstr("foo", "bar") -> null
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return Constant::getNullValue(CI->getType());
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// strstr("abcd", "bc") -> gep((char*)"abcd", 1)
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Value *Result = CastToCStr(CI->getArgOperand(0), B);
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Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
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return B.CreateBitCast(Result, CI->getType());
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// fold strstr(x, "y") -> strchr(x, 'y').
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if (HasStr2 && ToFindStr.size() == 1)
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return B.CreateBitCast(EmitStrChr(CI->getArgOperand(0),
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ToFindStr[0], B, TD), CI->getType());
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//===---------------------------------------===//
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// 'memcmp' Optimizations
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struct MemCmpOpt : public LibCallOptimization {
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virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() ||
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!FT->getParamType(1)->isPointerTy() ||
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!FT->getReturnType()->isIntegerTy(32))
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Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1);
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if (LHS == RHS) // memcmp(s,s,x) -> 0
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return Constant::getNullValue(CI->getType());
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// Make sure we have a constant length.
593
ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
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uint64_t Len = LenC->getZExtValue();
597
if (Len == 0) // memcmp(s1,s2,0) -> 0
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return Constant::getNullValue(CI->getType());
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// memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS
602
Value *LHSV = B.CreateZExt(B.CreateLoad(CastToCStr(LHS, B), "lhsc"),
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CI->getType(), "lhsv");
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Value *RHSV = B.CreateZExt(B.CreateLoad(CastToCStr(RHS, B), "rhsc"),
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CI->getType(), "rhsv");
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return B.CreateSub(LHSV, RHSV, "chardiff");
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// Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
610
std::string LHSStr, RHSStr;
611
if (GetConstantStringInfo(LHS, LHSStr) &&
612
GetConstantStringInfo(RHS, RHSStr)) {
613
// Make sure we're not reading out-of-bounds memory.
614
if (Len > LHSStr.length() || Len > RHSStr.length())
616
uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len);
617
return ConstantInt::get(CI->getType(), Ret);
624
//===---------------------------------------===//
625
// 'memcpy' Optimizations
627
struct MemCpyOpt : public LibCallOptimization {
628
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
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// These optimizations require TargetData.
632
const FunctionType *FT = Callee->getFunctionType();
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if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
634
!FT->getParamType(0)->isPointerTy() ||
635
!FT->getParamType(1)->isPointerTy() ||
636
FT->getParamType(2) != TD->getIntPtrType(*Context))
639
// memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
640
EmitMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
641
CI->getArgOperand(2), 1, false, B, TD);
642
return CI->getArgOperand(0);
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//===---------------------------------------===//
647
// 'memmove' Optimizations
649
struct MemMoveOpt : public LibCallOptimization {
650
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
651
// These optimizations require TargetData.
654
const FunctionType *FT = Callee->getFunctionType();
655
if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
656
!FT->getParamType(0)->isPointerTy() ||
657
!FT->getParamType(1)->isPointerTy() ||
658
FT->getParamType(2) != TD->getIntPtrType(*Context))
661
// memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
662
EmitMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
663
CI->getArgOperand(2), 1, false, B, TD);
664
return CI->getArgOperand(0);
668
//===---------------------------------------===//
669
// 'memset' Optimizations
671
struct MemSetOpt : public LibCallOptimization {
672
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
673
// These optimizations require TargetData.
676
const FunctionType *FT = Callee->getFunctionType();
677
if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
678
!FT->getParamType(0)->isPointerTy() ||
679
!FT->getParamType(1)->isIntegerTy() ||
680
FT->getParamType(2) != TD->getIntPtrType(*Context))
683
// memset(p, v, n) -> llvm.memset(p, v, n, 1)
684
Value *Val = B.CreateIntCast(CI->getArgOperand(1),
685
Type::getInt8Ty(*Context), false);
686
EmitMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), false, B, TD);
687
return CI->getArgOperand(0);
691
//===----------------------------------------------------------------------===//
692
// Math Library Optimizations
693
//===----------------------------------------------------------------------===//
695
//===---------------------------------------===//
696
// 'pow*' Optimizations
698
struct PowOpt : public LibCallOptimization {
699
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
700
const FunctionType *FT = Callee->getFunctionType();
701
// Just make sure this has 2 arguments of the same FP type, which match the
703
if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
704
FT->getParamType(0) != FT->getParamType(1) ||
705
!FT->getParamType(0)->isFloatingPointTy())
708
Value *Op1 = CI->getArgOperand(0), *Op2 = CI->getArgOperand(1);
709
if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
710
if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
712
if (Op1C->isExactlyValue(2.0)) // pow(2.0, x) -> exp2(x)
713
return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
716
ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
717
if (Op2C == 0) return 0;
719
if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
720
return ConstantFP::get(CI->getType(), 1.0);
722
if (Op2C->isExactlyValue(0.5)) {
723
// Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
724
// This is faster than calling pow, and still handles negative zero
725
// and negative infinite correctly.
726
// TODO: In fast-math mode, this could be just sqrt(x).
727
// TODO: In finite-only mode, this could be just fabs(sqrt(x)).
728
Value *Inf = ConstantFP::getInfinity(CI->getType());
729
Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
730
Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B,
731
Callee->getAttributes());
732
Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B,
733
Callee->getAttributes());
734
Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf, "tmp");
735
Value *Sel = B.CreateSelect(FCmp, Inf, FAbs, "tmp");
739
if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
741
if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
742
return B.CreateFMul(Op1, Op1, "pow2");
743
if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
744
return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
750
//===---------------------------------------===//
751
// 'exp2' Optimizations
753
struct Exp2Opt : public LibCallOptimization {
754
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
755
const FunctionType *FT = Callee->getFunctionType();
756
// Just make sure this has 1 argument of FP type, which matches the
758
if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
759
!FT->getParamType(0)->isFloatingPointTy())
762
Value *Op = CI->getArgOperand(0);
763
// Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
764
// Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
766
if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
767
if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
768
LdExpArg = B.CreateSExt(OpC->getOperand(0),
769
Type::getInt32Ty(*Context), "tmp");
770
} else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
771
if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
772
LdExpArg = B.CreateZExt(OpC->getOperand(0),
773
Type::getInt32Ty(*Context), "tmp");
778
if (Op->getType()->isFloatTy())
780
else if (Op->getType()->isDoubleTy())
785
Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
786
if (!Op->getType()->isFloatTy())
787
One = ConstantExpr::getFPExtend(One, Op->getType());
789
Module *M = Caller->getParent();
790
Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
792
Type::getInt32Ty(*Context),NULL);
793
CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
794
if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
795
CI->setCallingConv(F->getCallingConv());
803
//===---------------------------------------===//
804
// Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
806
struct UnaryDoubleFPOpt : public LibCallOptimization {
807
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
808
const FunctionType *FT = Callee->getFunctionType();
809
if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
810
!FT->getParamType(0)->isDoubleTy())
813
// If this is something like 'floor((double)floatval)', convert to floorf.
814
FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getArgOperand(0));
815
if (Cast == 0 || !Cast->getOperand(0)->getType()->isFloatTy())
818
// floor((double)floatval) -> (double)floorf(floatval)
819
Value *V = Cast->getOperand(0);
820
V = EmitUnaryFloatFnCall(V, Callee->getName().data(), B,
821
Callee->getAttributes());
822
return B.CreateFPExt(V, Type::getDoubleTy(*Context));
826
//===----------------------------------------------------------------------===//
827
// Integer Optimizations
828
//===----------------------------------------------------------------------===//
830
//===---------------------------------------===//
831
// 'ffs*' Optimizations
833
struct FFSOpt : public LibCallOptimization {
834
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
835
const FunctionType *FT = Callee->getFunctionType();
836
// Just make sure this has 2 arguments of the same FP type, which match the
838
if (FT->getNumParams() != 1 ||
839
!FT->getReturnType()->isIntegerTy(32) ||
840
!FT->getParamType(0)->isIntegerTy())
843
Value *Op = CI->getArgOperand(0);
846
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
847
if (CI->getValue() == 0) // ffs(0) -> 0.
848
return Constant::getNullValue(CI->getType());
849
return ConstantInt::get(Type::getInt32Ty(*Context), // ffs(c) -> cttz(c)+1
850
CI->getValue().countTrailingZeros()+1);
853
// ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
854
const Type *ArgType = Op->getType();
855
Value *F = Intrinsic::getDeclaration(Callee->getParent(),
856
Intrinsic::cttz, &ArgType, 1);
857
Value *V = B.CreateCall(F, Op, "cttz");
858
V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1), "tmp");
859
V = B.CreateIntCast(V, Type::getInt32Ty(*Context), false, "tmp");
861
Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType), "tmp");
862
return B.CreateSelect(Cond, V,
863
ConstantInt::get(Type::getInt32Ty(*Context), 0));
867
//===---------------------------------------===//
868
// 'isdigit' Optimizations
870
struct IsDigitOpt : public LibCallOptimization {
871
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
872
const FunctionType *FT = Callee->getFunctionType();
873
// We require integer(i32)
874
if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
875
!FT->getParamType(0)->isIntegerTy(32))
878
// isdigit(c) -> (c-'0') <u 10
879
Value *Op = CI->getArgOperand(0);
880
Op = B.CreateSub(Op, ConstantInt::get(Type::getInt32Ty(*Context), '0'),
882
Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 10),
884
return B.CreateZExt(Op, CI->getType());
888
//===---------------------------------------===//
889
// 'isascii' Optimizations
891
struct IsAsciiOpt : public LibCallOptimization {
892
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
893
const FunctionType *FT = Callee->getFunctionType();
894
// We require integer(i32)
895
if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
896
!FT->getParamType(0)->isIntegerTy(32))
899
// isascii(c) -> c <u 128
900
Value *Op = CI->getArgOperand(0);
901
Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 128),
903
return B.CreateZExt(Op, CI->getType());
907
//===---------------------------------------===//
908
// 'abs', 'labs', 'llabs' Optimizations
910
struct AbsOpt : public LibCallOptimization {
911
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
912
const FunctionType *FT = Callee->getFunctionType();
913
// We require integer(integer) where the types agree.
914
if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
915
FT->getParamType(0) != FT->getReturnType())
918
// abs(x) -> x >s -1 ? x : -x
919
Value *Op = CI->getArgOperand(0);
920
Value *Pos = B.CreateICmpSGT(Op,
921
Constant::getAllOnesValue(Op->getType()),
923
Value *Neg = B.CreateNeg(Op, "neg");
924
return B.CreateSelect(Pos, Op, Neg);
929
//===---------------------------------------===//
930
// 'toascii' Optimizations
932
struct ToAsciiOpt : public LibCallOptimization {
933
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
934
const FunctionType *FT = Callee->getFunctionType();
935
// We require i32(i32)
936
if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
937
!FT->getParamType(0)->isIntegerTy(32))
940
// isascii(c) -> c & 0x7f
941
return B.CreateAnd(CI->getArgOperand(0),
942
ConstantInt::get(CI->getType(),0x7F));
946
//===----------------------------------------------------------------------===//
947
// Formatting and IO Optimizations
948
//===----------------------------------------------------------------------===//
950
//===---------------------------------------===//
951
// 'printf' Optimizations
953
struct PrintFOpt : public LibCallOptimization {
954
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
955
// Require one fixed pointer argument and an integer/void result.
956
const FunctionType *FT = Callee->getFunctionType();
957
if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
958
!(FT->getReturnType()->isIntegerTy() ||
959
FT->getReturnType()->isVoidTy()))
962
// Check for a fixed format string.
963
std::string FormatStr;
964
if (!GetConstantStringInfo(CI->getArgOperand(0), FormatStr))
967
// Empty format string -> noop.
968
if (FormatStr.empty()) // Tolerate printf's declared void.
969
return CI->use_empty() ? (Value*)CI :
970
ConstantInt::get(CI->getType(), 0);
972
// printf("x") -> putchar('x'), even for '%'. Return the result of putchar
973
// in case there is an error writing to stdout.
974
if (FormatStr.size() == 1) {
975
Value *Res = EmitPutChar(ConstantInt::get(Type::getInt32Ty(*Context),
976
FormatStr[0]), B, TD);
977
if (CI->use_empty()) return CI;
978
return B.CreateIntCast(Res, CI->getType(), true);
981
// printf("foo\n") --> puts("foo")
982
if (FormatStr[FormatStr.size()-1] == '\n' &&
983
FormatStr.find('%') == std::string::npos) { // no format characters.
984
// Create a string literal with no \n on it. We expect the constant merge
985
// pass to be run after this pass, to merge duplicate strings.
986
FormatStr.erase(FormatStr.end()-1);
987
Constant *C = ConstantArray::get(*Context, FormatStr, true);
988
C = new GlobalVariable(*Callee->getParent(), C->getType(), true,
989
GlobalVariable::InternalLinkage, C, "str");
991
return CI->use_empty() ? (Value*)CI :
992
ConstantInt::get(CI->getType(), FormatStr.size()+1);
995
// Optimize specific format strings.
996
// printf("%c", chr) --> putchar(chr)
997
if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
998
CI->getArgOperand(1)->getType()->isIntegerTy()) {
999
Value *Res = EmitPutChar(CI->getArgOperand(1), B, TD);
1001
if (CI->use_empty()) return CI;
1002
return B.CreateIntCast(Res, CI->getType(), true);
1005
// printf("%s\n", str) --> puts(str)
1006
if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
1007
CI->getArgOperand(1)->getType()->isPointerTy() &&
1009
EmitPutS(CI->getArgOperand(1), B, TD);
1016
//===---------------------------------------===//
1017
// 'sprintf' Optimizations
1019
struct SPrintFOpt : public LibCallOptimization {
1020
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1021
// Require two fixed pointer arguments and an integer result.
1022
const FunctionType *FT = Callee->getFunctionType();
1023
if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1024
!FT->getParamType(1)->isPointerTy() ||
1025
!FT->getReturnType()->isIntegerTy())
1028
// Check for a fixed format string.
1029
std::string FormatStr;
1030
if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr))
1033
// If we just have a format string (nothing else crazy) transform it.
1034
if (CI->getNumArgOperands() == 2) {
1035
// Make sure there's no % in the constant array. We could try to handle
1036
// %% -> % in the future if we cared.
1037
for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1038
if (FormatStr[i] == '%')
1039
return 0; // we found a format specifier, bail out.
1041
// These optimizations require TargetData.
1044
// sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1045
EmitMemCpy(CI->getArgOperand(0), CI->getArgOperand(1), // Copy the
1046
ConstantInt::get(TD->getIntPtrType(*Context), // nul byte.
1047
FormatStr.size() + 1), 1, false, B, TD);
1048
return ConstantInt::get(CI->getType(), FormatStr.size());
1051
// The remaining optimizations require the format string to be "%s" or "%c"
1052
// and have an extra operand.
1053
if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1054
CI->getNumArgOperands() < 3)
1057
// Decode the second character of the format string.
1058
if (FormatStr[1] == 'c') {
1059
// sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1060
if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0;
1061
Value *V = B.CreateTrunc(CI->getArgOperand(2),
1062
Type::getInt8Ty(*Context), "char");
1063
Value *Ptr = CastToCStr(CI->getArgOperand(0), B);
1064
B.CreateStore(V, Ptr);
1065
Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::getInt32Ty(*Context), 1),
1067
B.CreateStore(Constant::getNullValue(Type::getInt8Ty(*Context)), Ptr);
1069
return ConstantInt::get(CI->getType(), 1);
1072
if (FormatStr[1] == 's') {
1073
// These optimizations require TargetData.
1076
// sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1077
if (!CI->getArgOperand(2)->getType()->isPointerTy()) return 0;
1079
Value *Len = EmitStrLen(CI->getArgOperand(2), B, TD);
1080
Value *IncLen = B.CreateAdd(Len,
1081
ConstantInt::get(Len->getType(), 1),
1083
EmitMemCpy(CI->getArgOperand(0), CI->getArgOperand(2),
1084
IncLen, 1, false, B, TD);
1086
// The sprintf result is the unincremented number of bytes in the string.
1087
return B.CreateIntCast(Len, CI->getType(), false);
1093
//===---------------------------------------===//
1094
// 'fwrite' Optimizations
1096
struct FWriteOpt : public LibCallOptimization {
1097
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1098
// Require a pointer, an integer, an integer, a pointer, returning integer.
1099
const FunctionType *FT = Callee->getFunctionType();
1100
if (FT->getNumParams() != 4 || !FT->getParamType(0)->isPointerTy() ||
1101
!FT->getParamType(1)->isIntegerTy() ||
1102
!FT->getParamType(2)->isIntegerTy() ||
1103
!FT->getParamType(3)->isPointerTy() ||
1104
!FT->getReturnType()->isIntegerTy())
1107
// Get the element size and count.
1108
ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
1109
ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
1110
if (!SizeC || !CountC) return 0;
1111
uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1113
// If this is writing zero records, remove the call (it's a noop).
1115
return ConstantInt::get(CI->getType(), 0);
1117
// If this is writing one byte, turn it into fputc.
1118
if (Bytes == 1) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1119
Value *Char = B.CreateLoad(CastToCStr(CI->getArgOperand(0), B), "char");
1120
EmitFPutC(Char, CI->getArgOperand(3), B, TD);
1121
return ConstantInt::get(CI->getType(), 1);
1128
//===---------------------------------------===//
1129
// 'fputs' Optimizations
1131
struct FPutsOpt : public LibCallOptimization {
1132
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1133
// These optimizations require TargetData.
1136
// Require two pointers. Also, we can't optimize if return value is used.
1137
const FunctionType *FT = Callee->getFunctionType();
1138
if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1139
!FT->getParamType(1)->isPointerTy() ||
1143
// fputs(s,F) --> fwrite(s,1,strlen(s),F)
1144
uint64_t Len = GetStringLength(CI->getArgOperand(0));
1146
EmitFWrite(CI->getArgOperand(0),
1147
ConstantInt::get(TD->getIntPtrType(*Context), Len-1),
1148
CI->getArgOperand(1), B, TD);
1149
return CI; // Known to have no uses (see above).
1153
//===---------------------------------------===//
1154
// 'fprintf' Optimizations
1156
struct FPrintFOpt : public LibCallOptimization {
1157
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1158
// Require two fixed paramters as pointers and integer result.
1159
const FunctionType *FT = Callee->getFunctionType();
1160
if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1161
!FT->getParamType(1)->isPointerTy() ||
1162
!FT->getReturnType()->isIntegerTy())
1165
// All the optimizations depend on the format string.
1166
std::string FormatStr;
1167
if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr))
1170
// fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1171
if (CI->getNumArgOperands() == 2) {
1172
for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1173
if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1174
return 0; // We found a format specifier.
1176
// These optimizations require TargetData.
1179
EmitFWrite(CI->getArgOperand(1),
1180
ConstantInt::get(TD->getIntPtrType(*Context),
1182
CI->getArgOperand(0), B, TD);
1183
return ConstantInt::get(CI->getType(), FormatStr.size());
1186
// The remaining optimizations require the format string to be "%s" or "%c"
1187
// and have an extra operand.
1188
if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1189
CI->getNumArgOperands() < 3)
1192
// Decode the second character of the format string.
1193
if (FormatStr[1] == 'c') {
1194
// fprintf(F, "%c", chr) --> fputc(chr, F)
1195
if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0;
1196
EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, TD);
1197
return ConstantInt::get(CI->getType(), 1);
1200
if (FormatStr[1] == 's') {
1201
// fprintf(F, "%s", str) --> fputs(str, F)
1202
if (!CI->getArgOperand(2)->getType()->isPointerTy() || !CI->use_empty())
1204
EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TD);
1211
} // end anonymous namespace.
1213
//===----------------------------------------------------------------------===//
1214
// SimplifyLibCalls Pass Implementation
1215
//===----------------------------------------------------------------------===//
1218
/// This pass optimizes well known library functions from libc and libm.
1220
class SimplifyLibCalls : public FunctionPass {
1221
StringMap<LibCallOptimization*> Optimizations;
1222
// String and Memory LibCall Optimizations
1223
StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
1224
StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
1225
StrNCpyOpt StrNCpy; StrLenOpt StrLen;
1226
StrToOpt StrTo; StrStrOpt StrStr;
1227
MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
1228
// Math Library Optimizations
1229
PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
1230
// Integer Optimizations
1231
FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1233
// Formatting and IO Optimizations
1234
SPrintFOpt SPrintF; PrintFOpt PrintF;
1235
FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1237
bool Modified; // This is only used by doInitialization.
1239
static char ID; // Pass identification
1240
SimplifyLibCalls() : FunctionPass(ID), StrCpy(false), StrCpyChk(true) {}
1241
void InitOptimizations();
1242
bool runOnFunction(Function &F);
1244
void setDoesNotAccessMemory(Function &F);
1245
void setOnlyReadsMemory(Function &F);
1246
void setDoesNotThrow(Function &F);
1247
void setDoesNotCapture(Function &F, unsigned n);
1248
void setDoesNotAlias(Function &F, unsigned n);
1249
bool doInitialization(Module &M);
1251
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1254
char SimplifyLibCalls::ID = 0;
1255
} // end anonymous namespace.
1257
INITIALIZE_PASS(SimplifyLibCalls, "simplify-libcalls",
1258
"Simplify well-known library calls", false, false);
1260
// Public interface to the Simplify LibCalls pass.
1261
FunctionPass *llvm::createSimplifyLibCallsPass() {
1262
return new SimplifyLibCalls();
1265
/// Optimizations - Populate the Optimizations map with all the optimizations
1267
void SimplifyLibCalls::InitOptimizations() {
1268
// String and Memory LibCall Optimizations
1269
Optimizations["strcat"] = &StrCat;
1270
Optimizations["strncat"] = &StrNCat;
1271
Optimizations["strchr"] = &StrChr;
1272
Optimizations["strcmp"] = &StrCmp;
1273
Optimizations["strncmp"] = &StrNCmp;
1274
Optimizations["strcpy"] = &StrCpy;
1275
Optimizations["strncpy"] = &StrNCpy;
1276
Optimizations["strlen"] = &StrLen;
1277
Optimizations["strtol"] = &StrTo;
1278
Optimizations["strtod"] = &StrTo;
1279
Optimizations["strtof"] = &StrTo;
1280
Optimizations["strtoul"] = &StrTo;
1281
Optimizations["strtoll"] = &StrTo;
1282
Optimizations["strtold"] = &StrTo;
1283
Optimizations["strtoull"] = &StrTo;
1284
Optimizations["strstr"] = &StrStr;
1285
Optimizations["memcmp"] = &MemCmp;
1286
Optimizations["memcpy"] = &MemCpy;
1287
Optimizations["memmove"] = &MemMove;
1288
Optimizations["memset"] = &MemSet;
1290
// _chk variants of String and Memory LibCall Optimizations.
1291
Optimizations["__strcpy_chk"] = &StrCpyChk;
1293
// Math Library Optimizations
1294
Optimizations["powf"] = &Pow;
1295
Optimizations["pow"] = &Pow;
1296
Optimizations["powl"] = &Pow;
1297
Optimizations["llvm.pow.f32"] = &Pow;
1298
Optimizations["llvm.pow.f64"] = &Pow;
1299
Optimizations["llvm.pow.f80"] = &Pow;
1300
Optimizations["llvm.pow.f128"] = &Pow;
1301
Optimizations["llvm.pow.ppcf128"] = &Pow;
1302
Optimizations["exp2l"] = &Exp2;
1303
Optimizations["exp2"] = &Exp2;
1304
Optimizations["exp2f"] = &Exp2;
1305
Optimizations["llvm.exp2.ppcf128"] = &Exp2;
1306
Optimizations["llvm.exp2.f128"] = &Exp2;
1307
Optimizations["llvm.exp2.f80"] = &Exp2;
1308
Optimizations["llvm.exp2.f64"] = &Exp2;
1309
Optimizations["llvm.exp2.f32"] = &Exp2;
1312
Optimizations["floor"] = &UnaryDoubleFP;
1315
Optimizations["ceil"] = &UnaryDoubleFP;
1318
Optimizations["round"] = &UnaryDoubleFP;
1321
Optimizations["rint"] = &UnaryDoubleFP;
1323
#ifdef HAVE_NEARBYINTF
1324
Optimizations["nearbyint"] = &UnaryDoubleFP;
1327
// Integer Optimizations
1328
Optimizations["ffs"] = &FFS;
1329
Optimizations["ffsl"] = &FFS;
1330
Optimizations["ffsll"] = &FFS;
1331
Optimizations["abs"] = &Abs;
1332
Optimizations["labs"] = &Abs;
1333
Optimizations["llabs"] = &Abs;
1334
Optimizations["isdigit"] = &IsDigit;
1335
Optimizations["isascii"] = &IsAscii;
1336
Optimizations["toascii"] = &ToAscii;
1338
// Formatting and IO Optimizations
1339
Optimizations["sprintf"] = &SPrintF;
1340
Optimizations["printf"] = &PrintF;
1341
Optimizations["fwrite"] = &FWrite;
1342
Optimizations["fputs"] = &FPuts;
1343
Optimizations["fprintf"] = &FPrintF;
1347
/// runOnFunction - Top level algorithm.
1349
bool SimplifyLibCalls::runOnFunction(Function &F) {
1350
if (Optimizations.empty())
1351
InitOptimizations();
1353
const TargetData *TD = getAnalysisIfAvailable<TargetData>();
1355
IRBuilder<> Builder(F.getContext());
1357
bool Changed = false;
1358
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1359
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
1360
// Ignore non-calls.
1361
CallInst *CI = dyn_cast<CallInst>(I++);
1364
// Ignore indirect calls and calls to non-external functions.
1365
Function *Callee = CI->getCalledFunction();
1366
if (Callee == 0 || !Callee->isDeclaration() ||
1367
!(Callee->hasExternalLinkage() || Callee->hasDLLImportLinkage()))
1370
// Ignore unknown calls.
1371
LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
1374
// Set the builder to the instruction after the call.
1375
Builder.SetInsertPoint(BB, I);
1377
// Try to optimize this call.
1378
Value *Result = LCO->OptimizeCall(CI, TD, Builder);
1379
if (Result == 0) continue;
1381
DEBUG(dbgs() << "SimplifyLibCalls simplified: " << *CI;
1382
dbgs() << " into: " << *Result << "\n");
1384
// Something changed!
1388
// Inspect the instruction after the call (which was potentially just
1392
if (CI != Result && !CI->use_empty()) {
1393
CI->replaceAllUsesWith(Result);
1394
if (!Result->hasName())
1395
Result->takeName(CI);
1397
CI->eraseFromParent();
1403
// Utility methods for doInitialization.
1405
void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1406
if (!F.doesNotAccessMemory()) {
1407
F.setDoesNotAccessMemory();
1412
void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1413
if (!F.onlyReadsMemory()) {
1414
F.setOnlyReadsMemory();
1419
void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1420
if (!F.doesNotThrow()) {
1421
F.setDoesNotThrow();
1426
void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1427
if (!F.doesNotCapture(n)) {
1428
F.setDoesNotCapture(n);
1433
void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1434
if (!F.doesNotAlias(n)) {
1435
F.setDoesNotAlias(n);
1441
/// doInitialization - Add attributes to well-known functions.
1443
bool SimplifyLibCalls::doInitialization(Module &M) {
1445
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
1447
if (!F.isDeclaration())
1453
const FunctionType *FTy = F.getFunctionType();
1455
StringRef Name = F.getName();
1458
if (Name == "strlen") {
1459
if (FTy->getNumParams() != 1 ||
1460
!FTy->getParamType(0)->isPointerTy())
1462
setOnlyReadsMemory(F);
1464
setDoesNotCapture(F, 1);
1465
} else if (Name == "strchr" ||
1466
Name == "strrchr") {
1467
if (FTy->getNumParams() != 2 ||
1468
!FTy->getParamType(0)->isPointerTy() ||
1469
!FTy->getParamType(1)->isIntegerTy())
1471
setOnlyReadsMemory(F);
1473
} else if (Name == "strcpy" ||
1479
Name == "strtoul" ||
1480
Name == "strtoll" ||
1481
Name == "strtold" ||
1482
Name == "strncat" ||
1483
Name == "strncpy" ||
1484
Name == "strtoull") {
1485
if (FTy->getNumParams() < 2 ||
1486
!FTy->getParamType(1)->isPointerTy())
1489
setDoesNotCapture(F, 2);
1490
} else if (Name == "strxfrm") {
1491
if (FTy->getNumParams() != 3 ||
1492
!FTy->getParamType(0)->isPointerTy() ||
1493
!FTy->getParamType(1)->isPointerTy())
1496
setDoesNotCapture(F, 1);
1497
setDoesNotCapture(F, 2);
1498
} else if (Name == "strcmp" ||
1500
Name == "strncmp" ||
1501
Name == "strcspn" ||
1502
Name == "strcoll" ||
1503
Name == "strcasecmp" ||
1504
Name == "strncasecmp") {
1505
if (FTy->getNumParams() < 2 ||
1506
!FTy->getParamType(0)->isPointerTy() ||
1507
!FTy->getParamType(1)->isPointerTy())
1509
setOnlyReadsMemory(F);
1511
setDoesNotCapture(F, 1);
1512
setDoesNotCapture(F, 2);
1513
} else if (Name == "strstr" ||
1514
Name == "strpbrk") {
1515
if (FTy->getNumParams() != 2 ||
1516
!FTy->getParamType(1)->isPointerTy())
1518
setOnlyReadsMemory(F);
1520
setDoesNotCapture(F, 2);
1521
} else if (Name == "strtok" ||
1522
Name == "strtok_r") {
1523
if (FTy->getNumParams() < 2 ||
1524
!FTy->getParamType(1)->isPointerTy())
1527
setDoesNotCapture(F, 2);
1528
} else if (Name == "scanf" ||
1530
Name == "setvbuf") {
1531
if (FTy->getNumParams() < 1 ||
1532
!FTy->getParamType(0)->isPointerTy())
1535
setDoesNotCapture(F, 1);
1536
} else if (Name == "strdup" ||
1537
Name == "strndup") {
1538
if (FTy->getNumParams() < 1 ||
1539
!FTy->getReturnType()->isPointerTy() ||
1540
!FTy->getParamType(0)->isPointerTy())
1543
setDoesNotAlias(F, 0);
1544
setDoesNotCapture(F, 1);
1545
} else if (Name == "stat" ||
1547
Name == "sprintf" ||
1548
Name == "statvfs") {
1549
if (FTy->getNumParams() < 2 ||
1550
!FTy->getParamType(0)->isPointerTy() ||
1551
!FTy->getParamType(1)->isPointerTy())
1554
setDoesNotCapture(F, 1);
1555
setDoesNotCapture(F, 2);
1556
} else if (Name == "snprintf") {
1557
if (FTy->getNumParams() != 3 ||
1558
!FTy->getParamType(0)->isPointerTy() ||
1559
!FTy->getParamType(2)->isPointerTy())
1562
setDoesNotCapture(F, 1);
1563
setDoesNotCapture(F, 3);
1564
} else if (Name == "setitimer") {
1565
if (FTy->getNumParams() != 3 ||
1566
!FTy->getParamType(1)->isPointerTy() ||
1567
!FTy->getParamType(2)->isPointerTy())
1570
setDoesNotCapture(F, 2);
1571
setDoesNotCapture(F, 3);
1572
} else if (Name == "system") {
1573
if (FTy->getNumParams() != 1 ||
1574
!FTy->getParamType(0)->isPointerTy())
1576
// May throw; "system" is a valid pthread cancellation point.
1577
setDoesNotCapture(F, 1);
1581
if (Name == "malloc") {
1582
if (FTy->getNumParams() != 1 ||
1583
!FTy->getReturnType()->isPointerTy())
1586
setDoesNotAlias(F, 0);
1587
} else if (Name == "memcmp") {
1588
if (FTy->getNumParams() != 3 ||
1589
!FTy->getParamType(0)->isPointerTy() ||
1590
!FTy->getParamType(1)->isPointerTy())
1592
setOnlyReadsMemory(F);
1594
setDoesNotCapture(F, 1);
1595
setDoesNotCapture(F, 2);
1596
} else if (Name == "memchr" ||
1597
Name == "memrchr") {
1598
if (FTy->getNumParams() != 3)
1600
setOnlyReadsMemory(F);
1602
} else if (Name == "modf" ||
1606
Name == "memccpy" ||
1607
Name == "memmove") {
1608
if (FTy->getNumParams() < 2 ||
1609
!FTy->getParamType(1)->isPointerTy())
1612
setDoesNotCapture(F, 2);
1613
} else if (Name == "memalign") {
1614
if (!FTy->getReturnType()->isPointerTy())
1616
setDoesNotAlias(F, 0);
1617
} else if (Name == "mkdir" ||
1619
if (FTy->getNumParams() == 0 ||
1620
!FTy->getParamType(0)->isPointerTy())
1623
setDoesNotCapture(F, 1);
1627
if (Name == "realloc") {
1628
if (FTy->getNumParams() != 2 ||
1629
!FTy->getParamType(0)->isPointerTy() ||
1630
!FTy->getReturnType()->isPointerTy())
1633
setDoesNotAlias(F, 0);
1634
setDoesNotCapture(F, 1);
1635
} else if (Name == "read") {
1636
if (FTy->getNumParams() != 3 ||
1637
!FTy->getParamType(1)->isPointerTy())
1639
// May throw; "read" is a valid pthread cancellation point.
1640
setDoesNotCapture(F, 2);
1641
} else if (Name == "rmdir" ||
1644
Name == "realpath") {
1645
if (FTy->getNumParams() < 1 ||
1646
!FTy->getParamType(0)->isPointerTy())
1649
setDoesNotCapture(F, 1);
1650
} else if (Name == "rename" ||
1651
Name == "readlink") {
1652
if (FTy->getNumParams() < 2 ||
1653
!FTy->getParamType(0)->isPointerTy() ||
1654
!FTy->getParamType(1)->isPointerTy())
1657
setDoesNotCapture(F, 1);
1658
setDoesNotCapture(F, 2);
1662
if (Name == "write") {
1663
if (FTy->getNumParams() != 3 ||
1664
!FTy->getParamType(1)->isPointerTy())
1666
// May throw; "write" is a valid pthread cancellation point.
1667
setDoesNotCapture(F, 2);
1671
if (Name == "bcopy") {
1672
if (FTy->getNumParams() != 3 ||
1673
!FTy->getParamType(0)->isPointerTy() ||
1674
!FTy->getParamType(1)->isPointerTy())
1677
setDoesNotCapture(F, 1);
1678
setDoesNotCapture(F, 2);
1679
} else if (Name == "bcmp") {
1680
if (FTy->getNumParams() != 3 ||
1681
!FTy->getParamType(0)->isPointerTy() ||
1682
!FTy->getParamType(1)->isPointerTy())
1685
setOnlyReadsMemory(F);
1686
setDoesNotCapture(F, 1);
1687
setDoesNotCapture(F, 2);
1688
} else if (Name == "bzero") {
1689
if (FTy->getNumParams() != 2 ||
1690
!FTy->getParamType(0)->isPointerTy())
1693
setDoesNotCapture(F, 1);
1697
if (Name == "calloc") {
1698
if (FTy->getNumParams() != 2 ||
1699
!FTy->getReturnType()->isPointerTy())
1702
setDoesNotAlias(F, 0);
1703
} else if (Name == "chmod" ||
1705
Name == "ctermid" ||
1706
Name == "clearerr" ||
1707
Name == "closedir") {
1708
if (FTy->getNumParams() == 0 ||
1709
!FTy->getParamType(0)->isPointerTy())
1712
setDoesNotCapture(F, 1);
1716
if (Name == "atoi" ||
1720
if (FTy->getNumParams() != 1 ||
1721
!FTy->getParamType(0)->isPointerTy())
1724
setOnlyReadsMemory(F);
1725
setDoesNotCapture(F, 1);
1726
} else if (Name == "access") {
1727
if (FTy->getNumParams() != 2 ||
1728
!FTy->getParamType(0)->isPointerTy())
1731
setDoesNotCapture(F, 1);
1735
if (Name == "fopen") {
1736
if (FTy->getNumParams() != 2 ||
1737
!FTy->getReturnType()->isPointerTy() ||
1738
!FTy->getParamType(0)->isPointerTy() ||
1739
!FTy->getParamType(1)->isPointerTy())
1742
setDoesNotAlias(F, 0);
1743
setDoesNotCapture(F, 1);
1744
setDoesNotCapture(F, 2);
1745
} else if (Name == "fdopen") {
1746
if (FTy->getNumParams() != 2 ||
1747
!FTy->getReturnType()->isPointerTy() ||
1748
!FTy->getParamType(1)->isPointerTy())
1751
setDoesNotAlias(F, 0);
1752
setDoesNotCapture(F, 2);
1753
} else if (Name == "feof" ||
1763
Name == "fsetpos" ||
1764
Name == "flockfile" ||
1765
Name == "funlockfile" ||
1766
Name == "ftrylockfile") {
1767
if (FTy->getNumParams() == 0 ||
1768
!FTy->getParamType(0)->isPointerTy())
1771
setDoesNotCapture(F, 1);
1772
} else if (Name == "ferror") {
1773
if (FTy->getNumParams() != 1 ||
1774
!FTy->getParamType(0)->isPointerTy())
1777
setDoesNotCapture(F, 1);
1778
setOnlyReadsMemory(F);
1779
} else if (Name == "fputc" ||
1784
Name == "fstatvfs") {
1785
if (FTy->getNumParams() != 2 ||
1786
!FTy->getParamType(1)->isPointerTy())
1789
setDoesNotCapture(F, 2);
1790
} else if (Name == "fgets") {
1791
if (FTy->getNumParams() != 3 ||
1792
!FTy->getParamType(0)->isPointerTy() ||
1793
!FTy->getParamType(2)->isPointerTy())
1796
setDoesNotCapture(F, 3);
1797
} else if (Name == "fread" ||
1799
if (FTy->getNumParams() != 4 ||
1800
!FTy->getParamType(0)->isPointerTy() ||
1801
!FTy->getParamType(3)->isPointerTy())
1804
setDoesNotCapture(F, 1);
1805
setDoesNotCapture(F, 4);
1806
} else if (Name == "fputs" ||
1808
Name == "fprintf" ||
1809
Name == "fgetpos") {
1810
if (FTy->getNumParams() < 2 ||
1811
!FTy->getParamType(0)->isPointerTy() ||
1812
!FTy->getParamType(1)->isPointerTy())
1815
setDoesNotCapture(F, 1);
1816
setDoesNotCapture(F, 2);
1820
if (Name == "getc" ||
1821
Name == "getlogin_r" ||
1822
Name == "getc_unlocked") {
1823
if (FTy->getNumParams() == 0 ||
1824
!FTy->getParamType(0)->isPointerTy())
1827
setDoesNotCapture(F, 1);
1828
} else if (Name == "getenv") {
1829
if (FTy->getNumParams() != 1 ||
1830
!FTy->getParamType(0)->isPointerTy())
1833
setOnlyReadsMemory(F);
1834
setDoesNotCapture(F, 1);
1835
} else if (Name == "gets" ||
1836
Name == "getchar") {
1838
} else if (Name == "getitimer") {
1839
if (FTy->getNumParams() != 2 ||
1840
!FTy->getParamType(1)->isPointerTy())
1843
setDoesNotCapture(F, 2);
1844
} else if (Name == "getpwnam") {
1845
if (FTy->getNumParams() != 1 ||
1846
!FTy->getParamType(0)->isPointerTy())
1849
setDoesNotCapture(F, 1);
1853
if (Name == "ungetc") {
1854
if (FTy->getNumParams() != 2 ||
1855
!FTy->getParamType(1)->isPointerTy())
1858
setDoesNotCapture(F, 2);
1859
} else if (Name == "uname" ||
1861
Name == "unsetenv") {
1862
if (FTy->getNumParams() != 1 ||
1863
!FTy->getParamType(0)->isPointerTy())
1866
setDoesNotCapture(F, 1);
1867
} else if (Name == "utime" ||
1869
if (FTy->getNumParams() != 2 ||
1870
!FTy->getParamType(0)->isPointerTy() ||
1871
!FTy->getParamType(1)->isPointerTy())
1874
setDoesNotCapture(F, 1);
1875
setDoesNotCapture(F, 2);
1879
if (Name == "putc") {
1880
if (FTy->getNumParams() != 2 ||
1881
!FTy->getParamType(1)->isPointerTy())
1884
setDoesNotCapture(F, 2);
1885
} else if (Name == "puts" ||
1888
if (FTy->getNumParams() != 1 ||
1889
!FTy->getParamType(0)->isPointerTy())
1892
setDoesNotCapture(F, 1);
1893
} else if (Name == "pread" ||
1895
if (FTy->getNumParams() != 4 ||
1896
!FTy->getParamType(1)->isPointerTy())
1898
// May throw; these are valid pthread cancellation points.
1899
setDoesNotCapture(F, 2);
1900
} else if (Name == "putchar") {
1902
} else if (Name == "popen") {
1903
if (FTy->getNumParams() != 2 ||
1904
!FTy->getReturnType()->isPointerTy() ||
1905
!FTy->getParamType(0)->isPointerTy() ||
1906
!FTy->getParamType(1)->isPointerTy())
1909
setDoesNotAlias(F, 0);
1910
setDoesNotCapture(F, 1);
1911
setDoesNotCapture(F, 2);
1912
} else if (Name == "pclose") {
1913
if (FTy->getNumParams() != 1 ||
1914
!FTy->getParamType(0)->isPointerTy())
1917
setDoesNotCapture(F, 1);
1921
if (Name == "vscanf") {
1922
if (FTy->getNumParams() != 2 ||
1923
!FTy->getParamType(1)->isPointerTy())
1926
setDoesNotCapture(F, 1);
1927
} else if (Name == "vsscanf" ||
1928
Name == "vfscanf") {
1929
if (FTy->getNumParams() != 3 ||
1930
!FTy->getParamType(1)->isPointerTy() ||
1931
!FTy->getParamType(2)->isPointerTy())
1934
setDoesNotCapture(F, 1);
1935
setDoesNotCapture(F, 2);
1936
} else if (Name == "valloc") {
1937
if (!FTy->getReturnType()->isPointerTy())
1940
setDoesNotAlias(F, 0);
1941
} else if (Name == "vprintf") {
1942
if (FTy->getNumParams() != 2 ||
1943
!FTy->getParamType(0)->isPointerTy())
1946
setDoesNotCapture(F, 1);
1947
} else if (Name == "vfprintf" ||
1948
Name == "vsprintf") {
1949
if (FTy->getNumParams() != 3 ||
1950
!FTy->getParamType(0)->isPointerTy() ||
1951
!FTy->getParamType(1)->isPointerTy())
1954
setDoesNotCapture(F, 1);
1955
setDoesNotCapture(F, 2);
1956
} else if (Name == "vsnprintf") {
1957
if (FTy->getNumParams() != 4 ||
1958
!FTy->getParamType(0)->isPointerTy() ||
1959
!FTy->getParamType(2)->isPointerTy())
1962
setDoesNotCapture(F, 1);
1963
setDoesNotCapture(F, 3);
1967
if (Name == "open") {
1968
if (FTy->getNumParams() < 2 ||
1969
!FTy->getParamType(0)->isPointerTy())
1971
// May throw; "open" is a valid pthread cancellation point.
1972
setDoesNotCapture(F, 1);
1973
} else if (Name == "opendir") {
1974
if (FTy->getNumParams() != 1 ||
1975
!FTy->getReturnType()->isPointerTy() ||
1976
!FTy->getParamType(0)->isPointerTy())
1979
setDoesNotAlias(F, 0);
1980
setDoesNotCapture(F, 1);
1984
if (Name == "tmpfile") {
1985
if (!FTy->getReturnType()->isPointerTy())
1988
setDoesNotAlias(F, 0);
1989
} else if (Name == "times") {
1990
if (FTy->getNumParams() != 1 ||
1991
!FTy->getParamType(0)->isPointerTy())
1994
setDoesNotCapture(F, 1);
1998
if (Name == "htonl" ||
2001
setDoesNotAccessMemory(F);
2005
if (Name == "ntohl" ||
2008
setDoesNotAccessMemory(F);
2012
if (Name == "lstat") {
2013
if (FTy->getNumParams() != 2 ||
2014
!FTy->getParamType(0)->isPointerTy() ||
2015
!FTy->getParamType(1)->isPointerTy())
2018
setDoesNotCapture(F, 1);
2019
setDoesNotCapture(F, 2);
2020
} else if (Name == "lchown") {
2021
if (FTy->getNumParams() != 3 ||
2022
!FTy->getParamType(0)->isPointerTy())
2025
setDoesNotCapture(F, 1);
2029
if (Name == "qsort") {
2030
if (FTy->getNumParams() != 4 ||
2031
!FTy->getParamType(3)->isPointerTy())
2033
// May throw; places call through function pointer.
2034
setDoesNotCapture(F, 4);
2038
if (Name == "__strdup" ||
2039
Name == "__strndup") {
2040
if (FTy->getNumParams() < 1 ||
2041
!FTy->getReturnType()->isPointerTy() ||
2042
!FTy->getParamType(0)->isPointerTy())
2045
setDoesNotAlias(F, 0);
2046
setDoesNotCapture(F, 1);
2047
} else if (Name == "__strtok_r") {
2048
if (FTy->getNumParams() != 3 ||
2049
!FTy->getParamType(1)->isPointerTy())
2052
setDoesNotCapture(F, 2);
2053
} else if (Name == "_IO_getc") {
2054
if (FTy->getNumParams() != 1 ||
2055
!FTy->getParamType(0)->isPointerTy())
2058
setDoesNotCapture(F, 1);
2059
} else if (Name == "_IO_putc") {
2060
if (FTy->getNumParams() != 2 ||
2061
!FTy->getParamType(1)->isPointerTy())
2064
setDoesNotCapture(F, 2);
2068
if (Name == "\1__isoc99_scanf") {
2069
if (FTy->getNumParams() < 1 ||
2070
!FTy->getParamType(0)->isPointerTy())
2073
setDoesNotCapture(F, 1);
2074
} else if (Name == "\1stat64" ||
2075
Name == "\1lstat64" ||
2076
Name == "\1statvfs64" ||
2077
Name == "\1__isoc99_sscanf") {
2078
if (FTy->getNumParams() < 1 ||
2079
!FTy->getParamType(0)->isPointerTy() ||
2080
!FTy->getParamType(1)->isPointerTy())
2083
setDoesNotCapture(F, 1);
2084
setDoesNotCapture(F, 2);
2085
} else if (Name == "\1fopen64") {
2086
if (FTy->getNumParams() != 2 ||
2087
!FTy->getReturnType()->isPointerTy() ||
2088
!FTy->getParamType(0)->isPointerTy() ||
2089
!FTy->getParamType(1)->isPointerTy())
2092
setDoesNotAlias(F, 0);
2093
setDoesNotCapture(F, 1);
2094
setDoesNotCapture(F, 2);
2095
} else if (Name == "\1fseeko64" ||
2096
Name == "\1ftello64") {
2097
if (FTy->getNumParams() == 0 ||
2098
!FTy->getParamType(0)->isPointerTy())
2101
setDoesNotCapture(F, 1);
2102
} else if (Name == "\1tmpfile64") {
2103
if (!FTy->getReturnType()->isPointerTy())
2106
setDoesNotAlias(F, 0);
2107
} else if (Name == "\1fstat64" ||
2108
Name == "\1fstatvfs64") {
2109
if (FTy->getNumParams() != 2 ||
2110
!FTy->getParamType(1)->isPointerTy())
2113
setDoesNotCapture(F, 2);
2114
} else if (Name == "\1open64") {
2115
if (FTy->getNumParams() < 2 ||
2116
!FTy->getParamType(0)->isPointerTy())
2118
// May throw; "open" is a valid pthread cancellation point.
2119
setDoesNotCapture(F, 1);
2128
// Additional cases that we need to add to this file:
2131
// * cbrt(expN(X)) -> expN(x/3)
2132
// * cbrt(sqrt(x)) -> pow(x,1/6)
2133
// * cbrt(sqrt(x)) -> pow(x,1/9)
2136
// * cos(-x) -> cos(x)
2139
// * exp(log(x)) -> x
2142
// * log(exp(x)) -> x
2143
// * log(x**y) -> y*log(x)
2144
// * log(exp(y)) -> y*log(e)
2145
// * log(exp2(y)) -> y*log(2)
2146
// * log(exp10(y)) -> y*log(10)
2147
// * log(sqrt(x)) -> 0.5*log(x)
2148
// * log(pow(x,y)) -> y*log(x)
2150
// lround, lroundf, lroundl:
2151
// * lround(cnst) -> cnst'
2154
// * pow(exp(x),y) -> exp(x*y)
2155
// * pow(sqrt(x),y) -> pow(x,y*0.5)
2156
// * pow(pow(x,y),z)-> pow(x,y*z)
2159
// * puts("") -> putchar('\n')
2161
// round, roundf, roundl:
2162
// * round(cnst) -> cnst'
2165
// * signbit(cnst) -> cnst'
2166
// * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2168
// sqrt, sqrtf, sqrtl:
2169
// * sqrt(expN(x)) -> expN(x*0.5)
2170
// * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2171
// * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2174
// * stpcpy(str, "literal") ->
2175
// llvm.memcpy(str,"literal",strlen("literal")+1,1)
2177
// * strrchr(s,c) -> reverse_offset_of_in(c,s)
2178
// (if c is a constant integer and s is a constant string)
2179
// * strrchr(s1,0) -> strchr(s1,0)
2182
// * strpbrk(s,a) -> offset_in_for(s,a)
2183
// (if s and a are both constant strings)
2184
// * strpbrk(s,"") -> 0
2185
// * strpbrk(s,a) -> strchr(s,a[0]) (if a is constant string of length 1)
2188
// * strspn(s,a) -> const_int (if both args are constant)
2189
// * strspn("",a) -> 0
2190
// * strspn(s,"") -> 0
2191
// * strcspn(s,a) -> const_int (if both args are constant)
2192
// * strcspn("",a) -> 0
2193
// * strcspn(s,"") -> strlen(a)
2196
// * tan(atan(x)) -> x
2198
// trunc, truncf, truncl:
2199
// * trunc(cnst) -> cnst'
added
removed
libclamav/c++/llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp
