2357 lines
84 KiB
C++
2357 lines
84 KiB
C++
//===------ SimplifyLibCalls.cpp - Library calls simplifier ---------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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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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//===----------------------------------------------------------------------===//
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//
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// This is a utility pass used for testing the InstructionSimplify analysis.
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// The analysis is applied to every instruction, and if it simplifies then the
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// instruction is replaced by the simplification. If you are looking for a pass
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// that performs serious instruction folding, use the instcombine pass instead.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Utils/SimplifyLibCalls.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/StringMap.h"
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#include "llvm/ADT/Triple.h"
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#include "llvm/Analysis/TargetLibraryInfo.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/DiagnosticInfo.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/IRBuilder.h"
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#include "llvm/IR/IntrinsicInst.h"
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#include "llvm/IR/Intrinsics.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IR/PatternMatch.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Transforms/Utils/BuildLibCalls.h"
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#include "llvm/Transforms/Utils/Local.h"
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using namespace llvm;
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using namespace PatternMatch;
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static cl::opt<bool>
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ColdErrorCalls("error-reporting-is-cold", cl::init(true), cl::Hidden,
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cl::desc("Treat error-reporting calls as cold"));
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static cl::opt<bool>
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EnableUnsafeFPShrink("enable-double-float-shrink", cl::Hidden,
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cl::init(false),
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cl::desc("Enable unsafe double to float "
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"shrinking for math lib calls"));
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//===----------------------------------------------------------------------===//
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// Helper Functions
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//===----------------------------------------------------------------------===//
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static bool ignoreCallingConv(LibFunc::Func Func) {
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return Func == LibFunc::abs || Func == LibFunc::labs ||
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Func == LibFunc::llabs || Func == LibFunc::strlen;
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}
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/// Return true if it only matters that the value is equal or not-equal to zero.
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static bool isOnlyUsedInZeroEqualityComparison(Value *V) {
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for (User *U : V->users()) {
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if (ICmpInst *IC = dyn_cast<ICmpInst>(U))
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if (IC->isEquality())
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if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
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if (C->isNullValue())
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continue;
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// Unknown instruction.
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return false;
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}
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return true;
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}
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/// Return true if it is only used in equality comparisons with With.
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static bool isOnlyUsedInEqualityComparison(Value *V, Value *With) {
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for (User *U : V->users()) {
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if (ICmpInst *IC = dyn_cast<ICmpInst>(U))
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if (IC->isEquality() && IC->getOperand(1) == With)
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continue;
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// Unknown instruction.
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return false;
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}
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return true;
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}
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static bool callHasFloatingPointArgument(const CallInst *CI) {
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return any_of(CI->operands(), [](const Use &OI) {
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return OI->getType()->isFloatingPointTy();
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});
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}
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/// \brief Check whether the overloaded unary floating point function
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/// corresponding to \a Ty is available.
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static bool hasUnaryFloatFn(const TargetLibraryInfo *TLI, Type *Ty,
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LibFunc::Func DoubleFn, LibFunc::Func FloatFn,
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LibFunc::Func LongDoubleFn) {
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switch (Ty->getTypeID()) {
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case Type::FloatTyID:
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return TLI->has(FloatFn);
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case Type::DoubleTyID:
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return TLI->has(DoubleFn);
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default:
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return TLI->has(LongDoubleFn);
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}
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}
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//===----------------------------------------------------------------------===//
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// String and Memory Library Call Optimizations
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//===----------------------------------------------------------------------===//
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Value *LibCallSimplifier::optimizeStrCat(CallInst *CI, IRBuilder<> &B) {
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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)
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return nullptr;
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--Len; // Unbias length.
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// Handle the simple, do-nothing case: strcat(x, "") -> x
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if (Len == 0)
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return Dst;
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return emitStrLenMemCpy(Src, Dst, Len, B);
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}
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Value *LibCallSimplifier::emitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len,
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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, DL, TLI);
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if (!DstLen)
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return nullptr;
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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(B.getInt8Ty(), 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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B.CreateMemCpy(CpyDst, Src,
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ConstantInt::get(DL.getIntPtrType(Src->getContext()), Len + 1),
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1);
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return Dst;
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}
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Value *LibCallSimplifier::optimizeStrNCat(CallInst *CI, IRBuilder<> &B) {
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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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uint64_t Len;
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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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else
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return nullptr;
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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)
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return nullptr;
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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)
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return Dst;
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// We don't optimize this case.
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if (Len < SrcLen)
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return nullptr;
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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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return emitStrLenMemCpy(Src, Dst, SrcLen, B);
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}
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Value *LibCallSimplifier::optimizeStrChr(CallInst *CI, IRBuilder<> &B) {
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Function *Callee = CI->getCalledFunction();
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FunctionType *FT = Callee->getFunctionType();
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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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if (!CharC) {
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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 nullptr;
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return emitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
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ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len),
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B, DL, TLI);
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}
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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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StringRef Str;
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if (!getConstantStringInfo(SrcStr, Str)) {
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if (CharC->isZero()) // strchr(p, 0) -> p + strlen(p)
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return B.CreateGEP(B.getInt8Ty(), SrcStr, emitStrLen(SrcStr, B, DL, TLI),
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"strchr");
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return nullptr;
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}
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// Compute the offset, make sure to handle the case when we're searching for
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// zero (a weird way to spell strlen).
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size_t I = (0xFF & CharC->getSExtValue()) == 0
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? Str.size()
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: Str.find(CharC->getSExtValue());
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if (I == StringRef::npos) // Didn't find the char. strchr returns null.
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return Constant::getNullValue(CI->getType());
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// strchr(s+n,c) -> gep(s+n+i,c)
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return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "strchr");
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}
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Value *LibCallSimplifier::optimizeStrRChr(CallInst *CI, IRBuilder<> &B) {
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Value *SrcStr = CI->getArgOperand(0);
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ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
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// Cannot fold anything if we're not looking for a constant.
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if (!CharC)
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return nullptr;
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StringRef Str;
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if (!getConstantStringInfo(SrcStr, Str)) {
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// strrchr(s, 0) -> strchr(s, 0)
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if (CharC->isZero())
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return emitStrChr(SrcStr, '\0', B, TLI);
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return nullptr;
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}
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// Compute the offset.
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size_t I = (0xFF & CharC->getSExtValue()) == 0
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? Str.size()
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: Str.rfind(CharC->getSExtValue());
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if (I == StringRef::npos) // Didn't find the char. Return null.
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return Constant::getNullValue(CI->getType());
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// strrchr(s+n,c) -> gep(s+n+i,c)
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return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "strrchr");
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}
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Value *LibCallSimplifier::optimizeStrCmp(CallInst *CI, IRBuilder<> &B) {
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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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StringRef Str1, Str2;
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bool HasStr1 = getConstantStringInfo(Str1P, Str1);
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bool HasStr2 = getConstantStringInfo(Str2P, Str2);
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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(), Str1.compare(Str2));
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if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x
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return B.CreateNeg(
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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(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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if (Len1 && Len2) {
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return emitMemCmp(Str1P, Str2P,
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ConstantInt::get(DL.getIntPtrType(CI->getContext()),
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std::min(Len1, Len2)),
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B, DL, TLI);
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}
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return nullptr;
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}
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Value *LibCallSimplifier::optimizeStrNCmp(CallInst *CI, IRBuilder<> &B) {
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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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uint64_t Length;
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if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
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Length = LengthArg->getZExtValue();
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else
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return nullptr;
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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 (Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
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return emitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, DL, TLI);
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StringRef Str1, Str2;
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bool HasStr1 = getConstantStringInfo(Str1P, Str1);
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bool HasStr2 = getConstantStringInfo(Str2P, Str2);
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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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StringRef SubStr1 = Str1.substr(0, Length);
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StringRef SubStr2 = Str2.substr(0, Length);
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return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2));
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}
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if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> -*x
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return B.CreateNeg(
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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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return nullptr;
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}
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Value *LibCallSimplifier::optimizeStrCpy(CallInst *CI, IRBuilder<> &B) {
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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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return Src;
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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)
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return nullptr;
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// We have enough information to now generate the memcpy call to do the
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// copy for us. Make a memcpy to copy the nul byte with align = 1.
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B.CreateMemCpy(Dst, Src,
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ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len), 1);
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return Dst;
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}
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Value *LibCallSimplifier::optimizeStpCpy(CallInst *CI, IRBuilder<> &B) {
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Function *Callee = CI->getCalledFunction();
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Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
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if (Dst == Src) { // stpcpy(x,x) -> x+strlen(x)
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Value *StrLen = emitStrLen(Src, B, DL, TLI);
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return StrLen ? B.CreateInBoundsGEP(B.getInt8Ty(), Dst, StrLen) : nullptr;
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}
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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)
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return nullptr;
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Type *PT = Callee->getFunctionType()->getParamType(0);
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Value *LenV = ConstantInt::get(DL.getIntPtrType(PT), Len);
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Value *DstEnd = B.CreateGEP(B.getInt8Ty(), Dst,
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ConstantInt::get(DL.getIntPtrType(PT), Len - 1));
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// We have enough information to now generate the memcpy call to do the
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// copy for us. Make a memcpy to copy the nul byte with align = 1.
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B.CreateMemCpy(Dst, Src, LenV, 1);
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return DstEnd;
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}
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Value *LibCallSimplifier::optimizeStrNCpy(CallInst *CI, IRBuilder<> &B) {
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Function *Callee = CI->getCalledFunction();
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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)
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return nullptr;
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--SrcLen;
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if (SrcLen == 0) {
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// strncpy(x, "", y) -> memset(x, '\0', y, 1)
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B.CreateMemSet(Dst, B.getInt8('\0'), LenOp, 1);
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return Dst;
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}
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uint64_t Len;
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if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
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Len = LengthArg->getZExtValue();
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else
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return nullptr;
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if (Len == 0)
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return Dst; // strncpy(x, y, 0) -> x
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// Let strncpy handle the zero padding
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if (Len > SrcLen + 1)
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return nullptr;
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Type *PT = Callee->getFunctionType()->getParamType(0);
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// strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
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B.CreateMemCpy(Dst, Src, ConstantInt::get(DL.getIntPtrType(PT), Len), 1);
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return Dst;
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}
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Value *LibCallSimplifier::optimizeStrLen(CallInst *CI, IRBuilder<> &B) {
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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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// If s is a constant pointer pointing to a string literal, we can fold
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// strlen(s + x) to strlen(s) - x, when x is known to be in the range
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// [0, strlen(s)] or the string has a single null terminator '\0' at the end.
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// We only try to simplify strlen when the pointer s points to an array
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// of i8. Otherwise, we would need to scale the offset x before doing the
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// subtraction. This will make the optimization more complex, and it's not
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// very useful because calling strlen for a pointer of other types is
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// very uncommon.
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if (GEPOperator *GEP = dyn_cast<GEPOperator>(Src)) {
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if (!isGEPBasedOnPointerToString(GEP))
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return nullptr;
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StringRef Str;
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if (getConstantStringInfo(GEP->getOperand(0), Str, 0, false)) {
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size_t NullTermIdx = Str.find('\0');
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// If the string does not have '\0', leave it to strlen to compute
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// its length.
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if (NullTermIdx == StringRef::npos)
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return nullptr;
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Value *Offset = GEP->getOperand(2);
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unsigned BitWidth = Offset->getType()->getIntegerBitWidth();
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APInt KnownZero(BitWidth, 0);
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APInt KnownOne(BitWidth, 0);
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computeKnownBits(Offset, KnownZero, KnownOne, DL, 0, nullptr, CI,
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nullptr);
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KnownZero.flipAllBits();
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size_t ArrSize =
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cast<ArrayType>(GEP->getSourceElementType())->getNumElements();
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// KnownZero's bits are flipped, so zeros in KnownZero now represent
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// bits known to be zeros in Offset, and ones in KnowZero represent
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// bits unknown in Offset. Therefore, Offset is known to be in range
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// [0, NullTermIdx] when the flipped KnownZero is non-negative and
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// unsigned-less-than NullTermIdx.
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//
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// If Offset is not provably in the range [0, NullTermIdx], we can still
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// optimize if we can prove that the program has undefined behavior when
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// Offset is outside that range. That is the case when GEP->getOperand(0)
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// is a pointer to an object whose memory extent is NullTermIdx+1.
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if ((KnownZero.isNonNegative() && KnownZero.ule(NullTermIdx)) ||
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(GEP->isInBounds() && isa<GlobalVariable>(GEP->getOperand(0)) &&
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NullTermIdx == ArrSize - 1))
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return B.CreateSub(ConstantInt::get(CI->getType(), NullTermIdx),
|
|
Offset);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
// strlen(x?"foo":"bars") --> x ? 3 : 4
|
|
if (SelectInst *SI = dyn_cast<SelectInst>(Src)) {
|
|
uint64_t LenTrue = GetStringLength(SI->getTrueValue());
|
|
uint64_t LenFalse = GetStringLength(SI->getFalseValue());
|
|
if (LenTrue && LenFalse) {
|
|
Function *Caller = CI->getParent()->getParent();
|
|
emitOptimizationRemark(CI->getContext(), "simplify-libcalls", *Caller,
|
|
SI->getDebugLoc(),
|
|
"folded strlen(select) to select of constants");
|
|
return B.CreateSelect(SI->getCondition(),
|
|
ConstantInt::get(CI->getType(), LenTrue - 1),
|
|
ConstantInt::get(CI->getType(), LenFalse - 1));
|
|
}
|
|
}
|
|
|
|
// strlen(x) != 0 --> *x != 0
|
|
// strlen(x) == 0 --> *x == 0
|
|
if (isOnlyUsedInZeroEqualityComparison(CI))
|
|
return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeStrPBrk(CallInst *CI, IRBuilder<> &B) {
|
|
StringRef S1, S2;
|
|
bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
|
|
bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
|
|
|
|
// strpbrk(s, "") -> nullptr
|
|
// strpbrk("", s) -> nullptr
|
|
if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// Constant folding.
|
|
if (HasS1 && HasS2) {
|
|
size_t I = S1.find_first_of(S2);
|
|
if (I == StringRef::npos) // No match.
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
return B.CreateGEP(B.getInt8Ty(), CI->getArgOperand(0), B.getInt64(I),
|
|
"strpbrk");
|
|
}
|
|
|
|
// strpbrk(s, "a") -> strchr(s, 'a')
|
|
if (HasS2 && S2.size() == 1)
|
|
return emitStrChr(CI->getArgOperand(0), S2[0], B, TLI);
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeStrTo(CallInst *CI, IRBuilder<> &B) {
|
|
Value *EndPtr = CI->getArgOperand(1);
|
|
if (isa<ConstantPointerNull>(EndPtr)) {
|
|
// With a null EndPtr, this function won't capture the main argument.
|
|
// It would be readonly too, except that it still may write to errno.
|
|
CI->addAttribute(1, Attribute::NoCapture);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeStrSpn(CallInst *CI, IRBuilder<> &B) {
|
|
StringRef S1, S2;
|
|
bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
|
|
bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
|
|
|
|
// strspn(s, "") -> 0
|
|
// strspn("", s) -> 0
|
|
if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// Constant folding.
|
|
if (HasS1 && HasS2) {
|
|
size_t Pos = S1.find_first_not_of(S2);
|
|
if (Pos == StringRef::npos)
|
|
Pos = S1.size();
|
|
return ConstantInt::get(CI->getType(), Pos);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeStrCSpn(CallInst *CI, IRBuilder<> &B) {
|
|
StringRef S1, S2;
|
|
bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
|
|
bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
|
|
|
|
// strcspn("", s) -> 0
|
|
if (HasS1 && S1.empty())
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// Constant folding.
|
|
if (HasS1 && HasS2) {
|
|
size_t Pos = S1.find_first_of(S2);
|
|
if (Pos == StringRef::npos)
|
|
Pos = S1.size();
|
|
return ConstantInt::get(CI->getType(), Pos);
|
|
}
|
|
|
|
// strcspn(s, "") -> strlen(s)
|
|
if (HasS2 && S2.empty())
|
|
return emitStrLen(CI->getArgOperand(0), B, DL, TLI);
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeStrStr(CallInst *CI, IRBuilder<> &B) {
|
|
// fold strstr(x, x) -> x.
|
|
if (CI->getArgOperand(0) == CI->getArgOperand(1))
|
|
return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
|
|
|
|
// fold strstr(a, b) == a -> strncmp(a, b, strlen(b)) == 0
|
|
if (isOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
|
|
Value *StrLen = emitStrLen(CI->getArgOperand(1), B, DL, TLI);
|
|
if (!StrLen)
|
|
return nullptr;
|
|
Value *StrNCmp = emitStrNCmp(CI->getArgOperand(0), CI->getArgOperand(1),
|
|
StrLen, B, DL, TLI);
|
|
if (!StrNCmp)
|
|
return nullptr;
|
|
for (auto UI = CI->user_begin(), UE = CI->user_end(); UI != UE;) {
|
|
ICmpInst *Old = cast<ICmpInst>(*UI++);
|
|
Value *Cmp =
|
|
B.CreateICmp(Old->getPredicate(), StrNCmp,
|
|
ConstantInt::getNullValue(StrNCmp->getType()), "cmp");
|
|
replaceAllUsesWith(Old, Cmp);
|
|
}
|
|
return CI;
|
|
}
|
|
|
|
// See if either input string is a constant string.
|
|
StringRef SearchStr, ToFindStr;
|
|
bool HasStr1 = getConstantStringInfo(CI->getArgOperand(0), SearchStr);
|
|
bool HasStr2 = getConstantStringInfo(CI->getArgOperand(1), ToFindStr);
|
|
|
|
// fold strstr(x, "") -> x.
|
|
if (HasStr2 && ToFindStr.empty())
|
|
return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
|
|
|
|
// If both strings are known, constant fold it.
|
|
if (HasStr1 && HasStr2) {
|
|
size_t Offset = SearchStr.find(ToFindStr);
|
|
|
|
if (Offset == StringRef::npos) // strstr("foo", "bar") -> null
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// strstr("abcd", "bc") -> gep((char*)"abcd", 1)
|
|
Value *Result = castToCStr(CI->getArgOperand(0), B);
|
|
Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
|
|
return B.CreateBitCast(Result, CI->getType());
|
|
}
|
|
|
|
// fold strstr(x, "y") -> strchr(x, 'y').
|
|
if (HasStr2 && ToFindStr.size() == 1) {
|
|
Value *StrChr = emitStrChr(CI->getArgOperand(0), ToFindStr[0], B, TLI);
|
|
return StrChr ? B.CreateBitCast(StrChr, CI->getType()) : nullptr;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeMemChr(CallInst *CI, IRBuilder<> &B) {
|
|
Value *SrcStr = CI->getArgOperand(0);
|
|
ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
|
|
ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
|
|
|
|
// memchr(x, y, 0) -> null
|
|
if (LenC && LenC->isNullValue())
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// From now on we need at least constant length and string.
|
|
StringRef Str;
|
|
if (!LenC || !getConstantStringInfo(SrcStr, Str, 0, /*TrimAtNul=*/false))
|
|
return nullptr;
|
|
|
|
// Truncate the string to LenC. If Str is smaller than LenC we will still only
|
|
// scan the string, as reading past the end of it is undefined and we can just
|
|
// return null if we don't find the char.
|
|
Str = Str.substr(0, LenC->getZExtValue());
|
|
|
|
// If the char is variable but the input str and length are not we can turn
|
|
// this memchr call into a simple bit field test. Of course this only works
|
|
// when the return value is only checked against null.
|
|
//
|
|
// It would be really nice to reuse switch lowering here but we can't change
|
|
// the CFG at this point.
|
|
//
|
|
// memchr("\r\n", C, 2) != nullptr -> (C & ((1 << '\r') | (1 << '\n'))) != 0
|
|
// after bounds check.
|
|
if (!CharC && !Str.empty() && isOnlyUsedInZeroEqualityComparison(CI)) {
|
|
unsigned char Max =
|
|
*std::max_element(reinterpret_cast<const unsigned char *>(Str.begin()),
|
|
reinterpret_cast<const unsigned char *>(Str.end()));
|
|
|
|
// Make sure the bit field we're about to create fits in a register on the
|
|
// target.
|
|
// FIXME: On a 64 bit architecture this prevents us from using the
|
|
// interesting range of alpha ascii chars. We could do better by emitting
|
|
// two bitfields or shifting the range by 64 if no lower chars are used.
|
|
if (!DL.fitsInLegalInteger(Max + 1))
|
|
return nullptr;
|
|
|
|
// For the bit field use a power-of-2 type with at least 8 bits to avoid
|
|
// creating unnecessary illegal types.
|
|
unsigned char Width = NextPowerOf2(std::max((unsigned char)7, Max));
|
|
|
|
// Now build the bit field.
|
|
APInt Bitfield(Width, 0);
|
|
for (char C : Str)
|
|
Bitfield.setBit((unsigned char)C);
|
|
Value *BitfieldC = B.getInt(Bitfield);
|
|
|
|
// First check that the bit field access is within bounds.
|
|
Value *C = B.CreateZExtOrTrunc(CI->getArgOperand(1), BitfieldC->getType());
|
|
Value *Bounds = B.CreateICmp(ICmpInst::ICMP_ULT, C, B.getIntN(Width, Width),
|
|
"memchr.bounds");
|
|
|
|
// Create code that checks if the given bit is set in the field.
|
|
Value *Shl = B.CreateShl(B.getIntN(Width, 1ULL), C);
|
|
Value *Bits = B.CreateIsNotNull(B.CreateAnd(Shl, BitfieldC), "memchr.bits");
|
|
|
|
// Finally merge both checks and cast to pointer type. The inttoptr
|
|
// implicitly zexts the i1 to intptr type.
|
|
return B.CreateIntToPtr(B.CreateAnd(Bounds, Bits, "memchr"), CI->getType());
|
|
}
|
|
|
|
// Check if all arguments are constants. If so, we can constant fold.
|
|
if (!CharC)
|
|
return nullptr;
|
|
|
|
// Compute the offset.
|
|
size_t I = Str.find(CharC->getSExtValue() & 0xFF);
|
|
if (I == StringRef::npos) // Didn't find the char. memchr returns null.
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// memchr(s+n,c,l) -> gep(s+n+i,c)
|
|
return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "memchr");
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeMemCmp(CallInst *CI, IRBuilder<> &B) {
|
|
Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1);
|
|
|
|
if (LHS == RHS) // memcmp(s,s,x) -> 0
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// Make sure we have a constant length.
|
|
ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
|
|
if (!LenC)
|
|
return nullptr;
|
|
uint64_t Len = LenC->getZExtValue();
|
|
|
|
if (Len == 0) // memcmp(s1,s2,0) -> 0
|
|
return Constant::getNullValue(CI->getType());
|
|
|
|
// memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS
|
|
if (Len == 1) {
|
|
Value *LHSV = B.CreateZExt(B.CreateLoad(castToCStr(LHS, B), "lhsc"),
|
|
CI->getType(), "lhsv");
|
|
Value *RHSV = B.CreateZExt(B.CreateLoad(castToCStr(RHS, B), "rhsc"),
|
|
CI->getType(), "rhsv");
|
|
return B.CreateSub(LHSV, RHSV, "chardiff");
|
|
}
|
|
|
|
// memcmp(S1,S2,N/8)==0 -> (*(intN_t*)S1 != *(intN_t*)S2)==0
|
|
if (DL.isLegalInteger(Len * 8) && isOnlyUsedInZeroEqualityComparison(CI)) {
|
|
|
|
IntegerType *IntType = IntegerType::get(CI->getContext(), Len * 8);
|
|
unsigned PrefAlignment = DL.getPrefTypeAlignment(IntType);
|
|
|
|
if (getKnownAlignment(LHS, DL, CI) >= PrefAlignment &&
|
|
getKnownAlignment(RHS, DL, CI) >= PrefAlignment) {
|
|
|
|
Type *LHSPtrTy =
|
|
IntType->getPointerTo(LHS->getType()->getPointerAddressSpace());
|
|
Type *RHSPtrTy =
|
|
IntType->getPointerTo(RHS->getType()->getPointerAddressSpace());
|
|
|
|
Value *LHSV =
|
|
B.CreateLoad(B.CreateBitCast(LHS, LHSPtrTy, "lhsc"), "lhsv");
|
|
Value *RHSV =
|
|
B.CreateLoad(B.CreateBitCast(RHS, RHSPtrTy, "rhsc"), "rhsv");
|
|
|
|
return B.CreateZExt(B.CreateICmpNE(LHSV, RHSV), CI->getType(), "memcmp");
|
|
}
|
|
}
|
|
|
|
// Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
|
|
StringRef LHSStr, RHSStr;
|
|
if (getConstantStringInfo(LHS, LHSStr) &&
|
|
getConstantStringInfo(RHS, RHSStr)) {
|
|
// Make sure we're not reading out-of-bounds memory.
|
|
if (Len > LHSStr.size() || Len > RHSStr.size())
|
|
return nullptr;
|
|
// Fold the memcmp and normalize the result. This way we get consistent
|
|
// results across multiple platforms.
|
|
uint64_t Ret = 0;
|
|
int Cmp = memcmp(LHSStr.data(), RHSStr.data(), Len);
|
|
if (Cmp < 0)
|
|
Ret = -1;
|
|
else if (Cmp > 0)
|
|
Ret = 1;
|
|
return ConstantInt::get(CI->getType(), Ret);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeMemCpy(CallInst *CI, IRBuilder<> &B) {
|
|
// memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
|
|
B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
|
|
CI->getArgOperand(2), 1);
|
|
return CI->getArgOperand(0);
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeMemMove(CallInst *CI, IRBuilder<> &B) {
|
|
// memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
|
|
B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
|
|
CI->getArgOperand(2), 1);
|
|
return CI->getArgOperand(0);
|
|
}
|
|
|
|
// TODO: Does this belong in BuildLibCalls or should all of those similar
|
|
// functions be moved here?
|
|
static Value *emitCalloc(Value *Num, Value *Size, const AttributeSet &Attrs,
|
|
IRBuilder<> &B, const TargetLibraryInfo &TLI) {
|
|
LibFunc::Func Func;
|
|
if (!TLI.getLibFunc("calloc", Func) || !TLI.has(Func))
|
|
return nullptr;
|
|
|
|
Module *M = B.GetInsertBlock()->getModule();
|
|
const DataLayout &DL = M->getDataLayout();
|
|
IntegerType *PtrType = DL.getIntPtrType((B.GetInsertBlock()->getContext()));
|
|
Value *Calloc = M->getOrInsertFunction("calloc", Attrs, B.getInt8PtrTy(),
|
|
PtrType, PtrType, nullptr);
|
|
CallInst *CI = B.CreateCall(Calloc, { Num, Size }, "calloc");
|
|
|
|
if (const auto *F = dyn_cast<Function>(Calloc->stripPointerCasts()))
|
|
CI->setCallingConv(F->getCallingConv());
|
|
|
|
return CI;
|
|
}
|
|
|
|
/// Fold memset[_chk](malloc(n), 0, n) --> calloc(1, n).
|
|
static Value *foldMallocMemset(CallInst *Memset, IRBuilder<> &B,
|
|
const TargetLibraryInfo &TLI) {
|
|
// This has to be a memset of zeros (bzero).
|
|
auto *FillValue = dyn_cast<ConstantInt>(Memset->getArgOperand(1));
|
|
if (!FillValue || FillValue->getZExtValue() != 0)
|
|
return nullptr;
|
|
|
|
// TODO: We should handle the case where the malloc has more than one use.
|
|
// This is necessary to optimize common patterns such as when the result of
|
|
// the malloc is checked against null or when a memset intrinsic is used in
|
|
// place of a memset library call.
|
|
auto *Malloc = dyn_cast<CallInst>(Memset->getArgOperand(0));
|
|
if (!Malloc || !Malloc->hasOneUse())
|
|
return nullptr;
|
|
|
|
// Is the inner call really malloc()?
|
|
Function *InnerCallee = Malloc->getCalledFunction();
|
|
LibFunc::Func Func;
|
|
if (!TLI.getLibFunc(*InnerCallee, Func) || !TLI.has(Func) ||
|
|
Func != LibFunc::malloc)
|
|
return nullptr;
|
|
|
|
// The memset must cover the same number of bytes that are malloc'd.
|
|
if (Memset->getArgOperand(2) != Malloc->getArgOperand(0))
|
|
return nullptr;
|
|
|
|
// Replace the malloc with a calloc. We need the data layout to know what the
|
|
// actual size of a 'size_t' parameter is.
|
|
B.SetInsertPoint(Malloc->getParent(), ++Malloc->getIterator());
|
|
const DataLayout &DL = Malloc->getModule()->getDataLayout();
|
|
IntegerType *SizeType = DL.getIntPtrType(B.GetInsertBlock()->getContext());
|
|
Value *Calloc = emitCalloc(ConstantInt::get(SizeType, 1),
|
|
Malloc->getArgOperand(0), Malloc->getAttributes(),
|
|
B, TLI);
|
|
if (!Calloc)
|
|
return nullptr;
|
|
|
|
Malloc->replaceAllUsesWith(Calloc);
|
|
Malloc->eraseFromParent();
|
|
|
|
return Calloc;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeMemSet(CallInst *CI, IRBuilder<> &B) {
|
|
if (auto *Calloc = foldMallocMemset(CI, B, *TLI))
|
|
return Calloc;
|
|
|
|
// memset(p, v, n) -> llvm.memset(p, v, n, 1)
|
|
Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
|
|
B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
|
|
return CI->getArgOperand(0);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Math Library Optimizations
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// Return a variant of Val with float type.
|
|
/// Currently this works in two cases: If Val is an FPExtension of a float
|
|
/// value to something bigger, simply return the operand.
|
|
/// If Val is a ConstantFP but can be converted to a float ConstantFP without
|
|
/// loss of precision do so.
|
|
static Value *valueHasFloatPrecision(Value *Val) {
|
|
if (FPExtInst *Cast = dyn_cast<FPExtInst>(Val)) {
|
|
Value *Op = Cast->getOperand(0);
|
|
if (Op->getType()->isFloatTy())
|
|
return Op;
|
|
}
|
|
if (ConstantFP *Const = dyn_cast<ConstantFP>(Val)) {
|
|
APFloat F = Const->getValueAPF();
|
|
bool losesInfo;
|
|
(void)F.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven,
|
|
&losesInfo);
|
|
if (!losesInfo)
|
|
return ConstantFP::get(Const->getContext(), F);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
/// Shrink double -> float for unary functions like 'floor'.
|
|
static Value *optimizeUnaryDoubleFP(CallInst *CI, IRBuilder<> &B,
|
|
bool CheckRetType) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
// We know this libcall has a valid prototype, but we don't know which.
|
|
if (!CI->getType()->isDoubleTy())
|
|
return nullptr;
|
|
|
|
if (CheckRetType) {
|
|
// Check if all the uses for function like 'sin' are converted to float.
|
|
for (User *U : CI->users()) {
|
|
FPTruncInst *Cast = dyn_cast<FPTruncInst>(U);
|
|
if (!Cast || !Cast->getType()->isFloatTy())
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
// If this is something like 'floor((double)floatval)', convert to floorf.
|
|
Value *V = valueHasFloatPrecision(CI->getArgOperand(0));
|
|
if (V == nullptr)
|
|
return nullptr;
|
|
|
|
// Propagate fast-math flags from the existing call to the new call.
|
|
IRBuilder<>::FastMathFlagGuard Guard(B);
|
|
B.setFastMathFlags(CI->getFastMathFlags());
|
|
|
|
// floor((double)floatval) -> (double)floorf(floatval)
|
|
if (Callee->isIntrinsic()) {
|
|
Module *M = CI->getModule();
|
|
Intrinsic::ID IID = Callee->getIntrinsicID();
|
|
Function *F = Intrinsic::getDeclaration(M, IID, B.getFloatTy());
|
|
V = B.CreateCall(F, V);
|
|
} else {
|
|
// The call is a library call rather than an intrinsic.
|
|
V = emitUnaryFloatFnCall(V, Callee->getName(), B, Callee->getAttributes());
|
|
}
|
|
|
|
return B.CreateFPExt(V, B.getDoubleTy());
|
|
}
|
|
|
|
/// Shrink double -> float for binary functions like 'fmin/fmax'.
|
|
static Value *optimizeBinaryDoubleFP(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
// We know this libcall has a valid prototype, but we don't know which.
|
|
if (!CI->getType()->isDoubleTy())
|
|
return nullptr;
|
|
|
|
// If this is something like 'fmin((double)floatval1, (double)floatval2)',
|
|
// or fmin(1.0, (double)floatval), then we convert it to fminf.
|
|
Value *V1 = valueHasFloatPrecision(CI->getArgOperand(0));
|
|
if (V1 == nullptr)
|
|
return nullptr;
|
|
Value *V2 = valueHasFloatPrecision(CI->getArgOperand(1));
|
|
if (V2 == nullptr)
|
|
return nullptr;
|
|
|
|
// Propagate fast-math flags from the existing call to the new call.
|
|
IRBuilder<>::FastMathFlagGuard Guard(B);
|
|
B.setFastMathFlags(CI->getFastMathFlags());
|
|
|
|
// fmin((double)floatval1, (double)floatval2)
|
|
// -> (double)fminf(floatval1, floatval2)
|
|
// TODO: Handle intrinsics in the same way as in optimizeUnaryDoubleFP().
|
|
Value *V = emitBinaryFloatFnCall(V1, V2, Callee->getName(), B,
|
|
Callee->getAttributes());
|
|
return B.CreateFPExt(V, B.getDoubleTy());
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeCos(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Ret = nullptr;
|
|
StringRef Name = Callee->getName();
|
|
if (UnsafeFPShrink && Name == "cos" && hasFloatVersion(Name))
|
|
Ret = optimizeUnaryDoubleFP(CI, B, true);
|
|
|
|
// cos(-x) -> cos(x)
|
|
Value *Op1 = CI->getArgOperand(0);
|
|
if (BinaryOperator::isFNeg(Op1)) {
|
|
BinaryOperator *BinExpr = cast<BinaryOperator>(Op1);
|
|
return B.CreateCall(Callee, BinExpr->getOperand(1), "cos");
|
|
}
|
|
return Ret;
|
|
}
|
|
|
|
static Value *getPow(Value *InnerChain[33], unsigned Exp, IRBuilder<> &B) {
|
|
// Multiplications calculated using Addition Chains.
|
|
// Refer: http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
|
|
|
|
assert(Exp != 0 && "Incorrect exponent 0 not handled");
|
|
|
|
if (InnerChain[Exp])
|
|
return InnerChain[Exp];
|
|
|
|
static const unsigned AddChain[33][2] = {
|
|
{0, 0}, // Unused.
|
|
{0, 0}, // Unused (base case = pow1).
|
|
{1, 1}, // Unused (pre-computed).
|
|
{1, 2}, {2, 2}, {2, 3}, {3, 3}, {2, 5}, {4, 4},
|
|
{1, 8}, {5, 5}, {1, 10}, {6, 6}, {4, 9}, {7, 7},
|
|
{3, 12}, {8, 8}, {8, 9}, {2, 16}, {1, 18}, {10, 10},
|
|
{6, 15}, {11, 11}, {3, 20}, {12, 12}, {8, 17}, {13, 13},
|
|
{3, 24}, {14, 14}, {4, 25}, {15, 15}, {3, 28}, {16, 16},
|
|
};
|
|
|
|
InnerChain[Exp] = B.CreateFMul(getPow(InnerChain, AddChain[Exp][0], B),
|
|
getPow(InnerChain, AddChain[Exp][1], B));
|
|
return InnerChain[Exp];
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizePow(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Ret = nullptr;
|
|
StringRef Name = Callee->getName();
|
|
if (UnsafeFPShrink && Name == "pow" && hasFloatVersion(Name))
|
|
Ret = optimizeUnaryDoubleFP(CI, B, true);
|
|
|
|
Value *Op1 = CI->getArgOperand(0), *Op2 = CI->getArgOperand(1);
|
|
|
|
// pow(1.0, x) -> 1.0
|
|
if (match(Op1, m_SpecificFP(1.0)))
|
|
return Op1;
|
|
// pow(2.0, x) -> llvm.exp2(x)
|
|
if (match(Op1, m_SpecificFP(2.0))) {
|
|
Value *Exp2 = Intrinsic::getDeclaration(CI->getModule(), Intrinsic::exp2,
|
|
CI->getType());
|
|
return B.CreateCall(Exp2, Op2, "exp2");
|
|
}
|
|
|
|
// There's no llvm.exp10 intrinsic yet, but, maybe, some day there will
|
|
// be one.
|
|
if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
|
|
// pow(10.0, x) -> exp10(x)
|
|
if (Op1C->isExactlyValue(10.0) &&
|
|
hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp10, LibFunc::exp10f,
|
|
LibFunc::exp10l))
|
|
return emitUnaryFloatFnCall(Op2, TLI->getName(LibFunc::exp10), B,
|
|
Callee->getAttributes());
|
|
}
|
|
|
|
// pow(exp(x), y) -> exp(x * y)
|
|
// pow(exp2(x), y) -> exp2(x * y)
|
|
// We enable these only with fast-math. Besides rounding differences, the
|
|
// transformation changes overflow and underflow behavior quite dramatically.
|
|
// Example: x = 1000, y = 0.001.
|
|
// pow(exp(x), y) = pow(inf, 0.001) = inf, whereas exp(x*y) = exp(1).
|
|
auto *OpC = dyn_cast<CallInst>(Op1);
|
|
if (OpC && OpC->hasUnsafeAlgebra() && CI->hasUnsafeAlgebra()) {
|
|
LibFunc::Func Func;
|
|
Function *OpCCallee = OpC->getCalledFunction();
|
|
if (OpCCallee && TLI->getLibFunc(OpCCallee->getName(), Func) &&
|
|
TLI->has(Func) && (Func == LibFunc::exp || Func == LibFunc::exp2)) {
|
|
IRBuilder<>::FastMathFlagGuard Guard(B);
|
|
B.setFastMathFlags(CI->getFastMathFlags());
|
|
Value *FMul = B.CreateFMul(OpC->getArgOperand(0), Op2, "mul");
|
|
return emitUnaryFloatFnCall(FMul, OpCCallee->getName(), B,
|
|
OpCCallee->getAttributes());
|
|
}
|
|
}
|
|
|
|
ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
|
|
if (!Op2C)
|
|
return Ret;
|
|
|
|
if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
|
|
return ConstantFP::get(CI->getType(), 1.0);
|
|
|
|
if (Op2C->isExactlyValue(0.5) &&
|
|
hasUnaryFloatFn(TLI, Op2->getType(), LibFunc::sqrt, LibFunc::sqrtf,
|
|
LibFunc::sqrtl) &&
|
|
hasUnaryFloatFn(TLI, Op2->getType(), LibFunc::fabs, LibFunc::fabsf,
|
|
LibFunc::fabsl)) {
|
|
|
|
// In -ffast-math, pow(x, 0.5) -> sqrt(x).
|
|
if (CI->hasUnsafeAlgebra()) {
|
|
IRBuilder<>::FastMathFlagGuard Guard(B);
|
|
B.setFastMathFlags(CI->getFastMathFlags());
|
|
|
|
// Unlike other math intrinsics, sqrt has differerent semantics
|
|
// from the libc function. See LangRef for details.
|
|
return emitUnaryFloatFnCall(Op1, TLI->getName(LibFunc::sqrt), B,
|
|
Callee->getAttributes());
|
|
}
|
|
|
|
// Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
|
|
// This is faster than calling pow, and still handles negative zero
|
|
// and negative infinity correctly.
|
|
// TODO: In finite-only mode, this could be just fabs(sqrt(x)).
|
|
Value *Inf = ConstantFP::getInfinity(CI->getType());
|
|
Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
|
|
Value *Sqrt = emitUnaryFloatFnCall(Op1, "sqrt", B, Callee->getAttributes());
|
|
Value *FAbs =
|
|
emitUnaryFloatFnCall(Sqrt, "fabs", B, Callee->getAttributes());
|
|
Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf);
|
|
Value *Sel = B.CreateSelect(FCmp, Inf, FAbs);
|
|
return Sel;
|
|
}
|
|
|
|
if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
|
|
return Op1;
|
|
if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
|
|
return B.CreateFMul(Op1, Op1, "pow2");
|
|
if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
|
|
return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0), Op1, "powrecip");
|
|
|
|
// In -ffast-math, generate repeated fmul instead of generating pow(x, n).
|
|
if (CI->hasUnsafeAlgebra()) {
|
|
APFloat V = abs(Op2C->getValueAPF());
|
|
// We limit to a max of 7 fmul(s). Thus max exponent is 32.
|
|
// This transformation applies to integer exponents only.
|
|
if (V.compare(APFloat(V.getSemantics(), 32.0)) == APFloat::cmpGreaterThan ||
|
|
!V.isInteger())
|
|
return nullptr;
|
|
|
|
// We will memoize intermediate products of the Addition Chain.
|
|
Value *InnerChain[33] = {nullptr};
|
|
InnerChain[1] = Op1;
|
|
InnerChain[2] = B.CreateFMul(Op1, Op1);
|
|
|
|
// We cannot readily convert a non-double type (like float) to a double.
|
|
// So we first convert V to something which could be converted to double.
|
|
bool ignored;
|
|
V.convert(APFloat::IEEEdouble, APFloat::rmTowardZero, &ignored);
|
|
|
|
// TODO: Should the new instructions propagate the 'fast' flag of the pow()?
|
|
Value *FMul = getPow(InnerChain, V.convertToDouble(), B);
|
|
// For negative exponents simply compute the reciprocal.
|
|
if (Op2C->isNegative())
|
|
FMul = B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0), FMul);
|
|
return FMul;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeExp2(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Ret = nullptr;
|
|
StringRef Name = Callee->getName();
|
|
if (UnsafeFPShrink && Name == "exp2" && hasFloatVersion(Name))
|
|
Ret = optimizeUnaryDoubleFP(CI, B, true);
|
|
|
|
Value *Op = CI->getArgOperand(0);
|
|
// Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
|
|
// Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
|
|
LibFunc::Func LdExp = LibFunc::ldexpl;
|
|
if (Op->getType()->isFloatTy())
|
|
LdExp = LibFunc::ldexpf;
|
|
else if (Op->getType()->isDoubleTy())
|
|
LdExp = LibFunc::ldexp;
|
|
|
|
if (TLI->has(LdExp)) {
|
|
Value *LdExpArg = nullptr;
|
|
if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
|
|
if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
|
|
LdExpArg = B.CreateSExt(OpC->getOperand(0), B.getInt32Ty());
|
|
} else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
|
|
if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
|
|
LdExpArg = B.CreateZExt(OpC->getOperand(0), B.getInt32Ty());
|
|
}
|
|
|
|
if (LdExpArg) {
|
|
Constant *One = ConstantFP::get(CI->getContext(), APFloat(1.0f));
|
|
if (!Op->getType()->isFloatTy())
|
|
One = ConstantExpr::getFPExtend(One, Op->getType());
|
|
|
|
Module *M = CI->getModule();
|
|
Value *NewCallee =
|
|
M->getOrInsertFunction(TLI->getName(LdExp), Op->getType(),
|
|
Op->getType(), B.getInt32Ty(), nullptr);
|
|
CallInst *CI = B.CreateCall(NewCallee, {One, LdExpArg});
|
|
if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
|
|
CI->setCallingConv(F->getCallingConv());
|
|
|
|
return CI;
|
|
}
|
|
}
|
|
return Ret;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeFabs(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Ret = nullptr;
|
|
StringRef Name = Callee->getName();
|
|
if (Name == "fabs" && hasFloatVersion(Name))
|
|
Ret = optimizeUnaryDoubleFP(CI, B, false);
|
|
|
|
Value *Op = CI->getArgOperand(0);
|
|
if (Instruction *I = dyn_cast<Instruction>(Op)) {
|
|
// Fold fabs(x * x) -> x * x; any squared FP value must already be positive.
|
|
if (I->getOpcode() == Instruction::FMul)
|
|
if (I->getOperand(0) == I->getOperand(1))
|
|
return Op;
|
|
}
|
|
return Ret;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
// If we can shrink the call to a float function rather than a double
|
|
// function, do that first.
|
|
StringRef Name = Callee->getName();
|
|
if ((Name == "fmin" || Name == "fmax") && hasFloatVersion(Name))
|
|
if (Value *Ret = optimizeBinaryDoubleFP(CI, B))
|
|
return Ret;
|
|
|
|
IRBuilder<>::FastMathFlagGuard Guard(B);
|
|
FastMathFlags FMF;
|
|
if (CI->hasUnsafeAlgebra()) {
|
|
// Unsafe algebra sets all fast-math-flags to true.
|
|
FMF.setUnsafeAlgebra();
|
|
} else {
|
|
// At a minimum, no-nans-fp-math must be true.
|
|
if (!CI->hasNoNaNs())
|
|
return nullptr;
|
|
// No-signed-zeros is implied by the definitions of fmax/fmin themselves:
|
|
// "Ideally, fmax would be sensitive to the sign of zero, for example
|
|
// fmax(-0. 0, +0. 0) would return +0; however, implementation in software
|
|
// might be impractical."
|
|
FMF.setNoSignedZeros();
|
|
FMF.setNoNaNs();
|
|
}
|
|
B.setFastMathFlags(FMF);
|
|
|
|
// We have a relaxed floating-point environment. We can ignore NaN-handling
|
|
// and transform to a compare and select. We do not have to consider errno or
|
|
// exceptions, because fmin/fmax do not have those.
|
|
Value *Op0 = CI->getArgOperand(0);
|
|
Value *Op1 = CI->getArgOperand(1);
|
|
Value *Cmp = Callee->getName().startswith("fmin") ?
|
|
B.CreateFCmpOLT(Op0, Op1) : B.CreateFCmpOGT(Op0, Op1);
|
|
return B.CreateSelect(Cmp, Op0, Op1);
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeLog(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Ret = nullptr;
|
|
StringRef Name = Callee->getName();
|
|
if (UnsafeFPShrink && hasFloatVersion(Name))
|
|
Ret = optimizeUnaryDoubleFP(CI, B, true);
|
|
|
|
if (!CI->hasUnsafeAlgebra())
|
|
return Ret;
|
|
Value *Op1 = CI->getArgOperand(0);
|
|
auto *OpC = dyn_cast<CallInst>(Op1);
|
|
|
|
// The earlier call must also be unsafe in order to do these transforms.
|
|
if (!OpC || !OpC->hasUnsafeAlgebra())
|
|
return Ret;
|
|
|
|
// log(pow(x,y)) -> y*log(x)
|
|
// This is only applicable to log, log2, log10.
|
|
if (Name != "log" && Name != "log2" && Name != "log10")
|
|
return Ret;
|
|
|
|
IRBuilder<>::FastMathFlagGuard Guard(B);
|
|
FastMathFlags FMF;
|
|
FMF.setUnsafeAlgebra();
|
|
B.setFastMathFlags(FMF);
|
|
|
|
LibFunc::Func Func;
|
|
Function *F = OpC->getCalledFunction();
|
|
if (F && ((TLI->getLibFunc(F->getName(), Func) && TLI->has(Func) &&
|
|
Func == LibFunc::pow) || F->getIntrinsicID() == Intrinsic::pow))
|
|
return B.CreateFMul(OpC->getArgOperand(1),
|
|
emitUnaryFloatFnCall(OpC->getOperand(0), Callee->getName(), B,
|
|
Callee->getAttributes()), "mul");
|
|
|
|
// log(exp2(y)) -> y*log(2)
|
|
if (F && Name == "log" && TLI->getLibFunc(F->getName(), Func) &&
|
|
TLI->has(Func) && Func == LibFunc::exp2)
|
|
return B.CreateFMul(
|
|
OpC->getArgOperand(0),
|
|
emitUnaryFloatFnCall(ConstantFP::get(CI->getType(), 2.0),
|
|
Callee->getName(), B, Callee->getAttributes()),
|
|
"logmul");
|
|
return Ret;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeSqrt(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Ret = nullptr;
|
|
if (TLI->has(LibFunc::sqrtf) && (Callee->getName() == "sqrt" ||
|
|
Callee->getIntrinsicID() == Intrinsic::sqrt))
|
|
Ret = optimizeUnaryDoubleFP(CI, B, true);
|
|
|
|
if (!CI->hasUnsafeAlgebra())
|
|
return Ret;
|
|
|
|
Instruction *I = dyn_cast<Instruction>(CI->getArgOperand(0));
|
|
if (!I || I->getOpcode() != Instruction::FMul || !I->hasUnsafeAlgebra())
|
|
return Ret;
|
|
|
|
// We're looking for a repeated factor in a multiplication tree,
|
|
// so we can do this fold: sqrt(x * x) -> fabs(x);
|
|
// or this fold: sqrt((x * x) * y) -> fabs(x) * sqrt(y).
|
|
Value *Op0 = I->getOperand(0);
|
|
Value *Op1 = I->getOperand(1);
|
|
Value *RepeatOp = nullptr;
|
|
Value *OtherOp = nullptr;
|
|
if (Op0 == Op1) {
|
|
// Simple match: the operands of the multiply are identical.
|
|
RepeatOp = Op0;
|
|
} else {
|
|
// Look for a more complicated pattern: one of the operands is itself
|
|
// a multiply, so search for a common factor in that multiply.
|
|
// Note: We don't bother looking any deeper than this first level or for
|
|
// variations of this pattern because instcombine's visitFMUL and/or the
|
|
// reassociation pass should give us this form.
|
|
Value *OtherMul0, *OtherMul1;
|
|
if (match(Op0, m_FMul(m_Value(OtherMul0), m_Value(OtherMul1)))) {
|
|
// Pattern: sqrt((x * y) * z)
|
|
if (OtherMul0 == OtherMul1 &&
|
|
cast<Instruction>(Op0)->hasUnsafeAlgebra()) {
|
|
// Matched: sqrt((x * x) * z)
|
|
RepeatOp = OtherMul0;
|
|
OtherOp = Op1;
|
|
}
|
|
}
|
|
}
|
|
if (!RepeatOp)
|
|
return Ret;
|
|
|
|
// Fast math flags for any created instructions should match the sqrt
|
|
// and multiply.
|
|
IRBuilder<>::FastMathFlagGuard Guard(B);
|
|
B.setFastMathFlags(I->getFastMathFlags());
|
|
|
|
// If we found a repeated factor, hoist it out of the square root and
|
|
// replace it with the fabs of that factor.
|
|
Module *M = Callee->getParent();
|
|
Type *ArgType = I->getType();
|
|
Value *Fabs = Intrinsic::getDeclaration(M, Intrinsic::fabs, ArgType);
|
|
Value *FabsCall = B.CreateCall(Fabs, RepeatOp, "fabs");
|
|
if (OtherOp) {
|
|
// If we found a non-repeated factor, we still need to get its square
|
|
// root. We then multiply that by the value that was simplified out
|
|
// of the square root calculation.
|
|
Value *Sqrt = Intrinsic::getDeclaration(M, Intrinsic::sqrt, ArgType);
|
|
Value *SqrtCall = B.CreateCall(Sqrt, OtherOp, "sqrt");
|
|
return B.CreateFMul(FabsCall, SqrtCall);
|
|
}
|
|
return FabsCall;
|
|
}
|
|
|
|
// TODO: Generalize to handle any trig function and its inverse.
|
|
Value *LibCallSimplifier::optimizeTan(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Ret = nullptr;
|
|
StringRef Name = Callee->getName();
|
|
if (UnsafeFPShrink && Name == "tan" && hasFloatVersion(Name))
|
|
Ret = optimizeUnaryDoubleFP(CI, B, true);
|
|
|
|
Value *Op1 = CI->getArgOperand(0);
|
|
auto *OpC = dyn_cast<CallInst>(Op1);
|
|
if (!OpC)
|
|
return Ret;
|
|
|
|
// Both calls must allow unsafe optimizations in order to remove them.
|
|
if (!CI->hasUnsafeAlgebra() || !OpC->hasUnsafeAlgebra())
|
|
return Ret;
|
|
|
|
// tan(atan(x)) -> x
|
|
// tanf(atanf(x)) -> x
|
|
// tanl(atanl(x)) -> x
|
|
LibFunc::Func Func;
|
|
Function *F = OpC->getCalledFunction();
|
|
if (F && TLI->getLibFunc(F->getName(), Func) && TLI->has(Func) &&
|
|
((Func == LibFunc::atan && Callee->getName() == "tan") ||
|
|
(Func == LibFunc::atanf && Callee->getName() == "tanf") ||
|
|
(Func == LibFunc::atanl && Callee->getName() == "tanl")))
|
|
Ret = OpC->getArgOperand(0);
|
|
return Ret;
|
|
}
|
|
|
|
static bool isTrigLibCall(CallInst *CI) {
|
|
// We can only hope to do anything useful if we can ignore things like errno
|
|
// and floating-point exceptions.
|
|
// We already checked the prototype.
|
|
return CI->hasFnAttr(Attribute::NoUnwind) &&
|
|
CI->hasFnAttr(Attribute::ReadNone);
|
|
}
|
|
|
|
static void insertSinCosCall(IRBuilder<> &B, Function *OrigCallee, Value *Arg,
|
|
bool UseFloat, Value *&Sin, Value *&Cos,
|
|
Value *&SinCos) {
|
|
Type *ArgTy = Arg->getType();
|
|
Type *ResTy;
|
|
StringRef Name;
|
|
|
|
Triple T(OrigCallee->getParent()->getTargetTriple());
|
|
if (UseFloat) {
|
|
Name = "__sincospif_stret";
|
|
|
|
assert(T.getArch() != Triple::x86 && "x86 messy and unsupported for now");
|
|
// x86_64 can't use {float, float} since that would be returned in both
|
|
// xmm0 and xmm1, which isn't what a real struct would do.
|
|
ResTy = T.getArch() == Triple::x86_64
|
|
? static_cast<Type *>(VectorType::get(ArgTy, 2))
|
|
: static_cast<Type *>(StructType::get(ArgTy, ArgTy, nullptr));
|
|
} else {
|
|
Name = "__sincospi_stret";
|
|
ResTy = StructType::get(ArgTy, ArgTy, nullptr);
|
|
}
|
|
|
|
Module *M = OrigCallee->getParent();
|
|
Value *Callee = M->getOrInsertFunction(Name, OrigCallee->getAttributes(),
|
|
ResTy, ArgTy, nullptr);
|
|
|
|
if (Instruction *ArgInst = dyn_cast<Instruction>(Arg)) {
|
|
// If the argument is an instruction, it must dominate all uses so put our
|
|
// sincos call there.
|
|
B.SetInsertPoint(ArgInst->getParent(), ++ArgInst->getIterator());
|
|
} else {
|
|
// Otherwise (e.g. for a constant) the beginning of the function is as
|
|
// good a place as any.
|
|
BasicBlock &EntryBB = B.GetInsertBlock()->getParent()->getEntryBlock();
|
|
B.SetInsertPoint(&EntryBB, EntryBB.begin());
|
|
}
|
|
|
|
SinCos = B.CreateCall(Callee, Arg, "sincospi");
|
|
|
|
if (SinCos->getType()->isStructTy()) {
|
|
Sin = B.CreateExtractValue(SinCos, 0, "sinpi");
|
|
Cos = B.CreateExtractValue(SinCos, 1, "cospi");
|
|
} else {
|
|
Sin = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 0),
|
|
"sinpi");
|
|
Cos = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 1),
|
|
"cospi");
|
|
}
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeSinCosPi(CallInst *CI, IRBuilder<> &B) {
|
|
// Make sure the prototype is as expected, otherwise the rest of the
|
|
// function is probably invalid and likely to abort.
|
|
if (!isTrigLibCall(CI))
|
|
return nullptr;
|
|
|
|
Value *Arg = CI->getArgOperand(0);
|
|
SmallVector<CallInst *, 1> SinCalls;
|
|
SmallVector<CallInst *, 1> CosCalls;
|
|
SmallVector<CallInst *, 1> SinCosCalls;
|
|
|
|
bool IsFloat = Arg->getType()->isFloatTy();
|
|
|
|
// Look for all compatible sinpi, cospi and sincospi calls with the same
|
|
// argument. If there are enough (in some sense) we can make the
|
|
// substitution.
|
|
Function *F = CI->getFunction();
|
|
for (User *U : Arg->users())
|
|
classifyArgUse(U, F, IsFloat, SinCalls, CosCalls, SinCosCalls);
|
|
|
|
// It's only worthwhile if both sinpi and cospi are actually used.
|
|
if (SinCosCalls.empty() && (SinCalls.empty() || CosCalls.empty()))
|
|
return nullptr;
|
|
|
|
Value *Sin, *Cos, *SinCos;
|
|
insertSinCosCall(B, CI->getCalledFunction(), Arg, IsFloat, Sin, Cos, SinCos);
|
|
|
|
replaceTrigInsts(SinCalls, Sin);
|
|
replaceTrigInsts(CosCalls, Cos);
|
|
replaceTrigInsts(SinCosCalls, SinCos);
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
void LibCallSimplifier::classifyArgUse(
|
|
Value *Val, Function *F, bool IsFloat,
|
|
SmallVectorImpl<CallInst *> &SinCalls,
|
|
SmallVectorImpl<CallInst *> &CosCalls,
|
|
SmallVectorImpl<CallInst *> &SinCosCalls) {
|
|
CallInst *CI = dyn_cast<CallInst>(Val);
|
|
|
|
if (!CI)
|
|
return;
|
|
|
|
// Don't consider calls in other functions.
|
|
if (CI->getFunction() != F)
|
|
return;
|
|
|
|
Function *Callee = CI->getCalledFunction();
|
|
LibFunc::Func Func;
|
|
if (!Callee || !TLI->getLibFunc(*Callee, Func) || !TLI->has(Func) ||
|
|
!isTrigLibCall(CI))
|
|
return;
|
|
|
|
if (IsFloat) {
|
|
if (Func == LibFunc::sinpif)
|
|
SinCalls.push_back(CI);
|
|
else if (Func == LibFunc::cospif)
|
|
CosCalls.push_back(CI);
|
|
else if (Func == LibFunc::sincospif_stret)
|
|
SinCosCalls.push_back(CI);
|
|
} else {
|
|
if (Func == LibFunc::sinpi)
|
|
SinCalls.push_back(CI);
|
|
else if (Func == LibFunc::cospi)
|
|
CosCalls.push_back(CI);
|
|
else if (Func == LibFunc::sincospi_stret)
|
|
SinCosCalls.push_back(CI);
|
|
}
|
|
}
|
|
|
|
void LibCallSimplifier::replaceTrigInsts(SmallVectorImpl<CallInst *> &Calls,
|
|
Value *Res) {
|
|
for (CallInst *C : Calls)
|
|
replaceAllUsesWith(C, Res);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Integer Library Call Optimizations
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
Value *LibCallSimplifier::optimizeFFS(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
Value *Op = CI->getArgOperand(0);
|
|
|
|
// Constant fold.
|
|
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
|
|
if (CI->isZero()) // ffs(0) -> 0.
|
|
return B.getInt32(0);
|
|
// ffs(c) -> cttz(c)+1
|
|
return B.getInt32(CI->getValue().countTrailingZeros() + 1);
|
|
}
|
|
|
|
// ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
|
|
Type *ArgType = Op->getType();
|
|
Value *F =
|
|
Intrinsic::getDeclaration(Callee->getParent(), Intrinsic::cttz, ArgType);
|
|
Value *V = B.CreateCall(F, {Op, B.getTrue()}, "cttz");
|
|
V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1));
|
|
V = B.CreateIntCast(V, B.getInt32Ty(), false);
|
|
|
|
Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType));
|
|
return B.CreateSelect(Cond, V, B.getInt32(0));
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeAbs(CallInst *CI, IRBuilder<> &B) {
|
|
// abs(x) -> x >s -1 ? x : -x
|
|
Value *Op = CI->getArgOperand(0);
|
|
Value *Pos =
|
|
B.CreateICmpSGT(Op, Constant::getAllOnesValue(Op->getType()), "ispos");
|
|
Value *Neg = B.CreateNeg(Op, "neg");
|
|
return B.CreateSelect(Pos, Op, Neg);
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeIsDigit(CallInst *CI, IRBuilder<> &B) {
|
|
// isdigit(c) -> (c-'0') <u 10
|
|
Value *Op = CI->getArgOperand(0);
|
|
Op = B.CreateSub(Op, B.getInt32('0'), "isdigittmp");
|
|
Op = B.CreateICmpULT(Op, B.getInt32(10), "isdigit");
|
|
return B.CreateZExt(Op, CI->getType());
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeIsAscii(CallInst *CI, IRBuilder<> &B) {
|
|
// isascii(c) -> c <u 128
|
|
Value *Op = CI->getArgOperand(0);
|
|
Op = B.CreateICmpULT(Op, B.getInt32(128), "isascii");
|
|
return B.CreateZExt(Op, CI->getType());
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeToAscii(CallInst *CI, IRBuilder<> &B) {
|
|
// toascii(c) -> c & 0x7f
|
|
return B.CreateAnd(CI->getArgOperand(0),
|
|
ConstantInt::get(CI->getType(), 0x7F));
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Formatting and IO Library Call Optimizations
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg);
|
|
|
|
Value *LibCallSimplifier::optimizeErrorReporting(CallInst *CI, IRBuilder<> &B,
|
|
int StreamArg) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
// Error reporting calls should be cold, mark them as such.
|
|
// This applies even to non-builtin calls: it is only a hint and applies to
|
|
// functions that the frontend might not understand as builtins.
|
|
|
|
// This heuristic was suggested in:
|
|
// Improving Static Branch Prediction in a Compiler
|
|
// Brian L. Deitrich, Ben-Chung Cheng, Wen-mei W. Hwu
|
|
// Proceedings of PACT'98, Oct. 1998, IEEE
|
|
if (!CI->hasFnAttr(Attribute::Cold) &&
|
|
isReportingError(Callee, CI, StreamArg)) {
|
|
CI->addAttribute(AttributeSet::FunctionIndex, Attribute::Cold);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg) {
|
|
if (!ColdErrorCalls || !Callee || !Callee->isDeclaration())
|
|
return false;
|
|
|
|
if (StreamArg < 0)
|
|
return true;
|
|
|
|
// These functions might be considered cold, but only if their stream
|
|
// argument is stderr.
|
|
|
|
if (StreamArg >= (int)CI->getNumArgOperands())
|
|
return false;
|
|
LoadInst *LI = dyn_cast<LoadInst>(CI->getArgOperand(StreamArg));
|
|
if (!LI)
|
|
return false;
|
|
GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getPointerOperand());
|
|
if (!GV || !GV->isDeclaration())
|
|
return false;
|
|
return GV->getName() == "stderr";
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizePrintFString(CallInst *CI, IRBuilder<> &B) {
|
|
// Check for a fixed format string.
|
|
StringRef FormatStr;
|
|
if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr))
|
|
return nullptr;
|
|
|
|
// Empty format string -> noop.
|
|
if (FormatStr.empty()) // Tolerate printf's declared void.
|
|
return CI->use_empty() ? (Value *)CI : ConstantInt::get(CI->getType(), 0);
|
|
|
|
// Do not do any of the following transformations if the printf return value
|
|
// is used, in general the printf return value is not compatible with either
|
|
// putchar() or puts().
|
|
if (!CI->use_empty())
|
|
return nullptr;
|
|
|
|
// printf("x") -> putchar('x'), even for "%" and "%%".
|
|
if (FormatStr.size() == 1 || FormatStr == "%%")
|
|
return emitPutChar(B.getInt32(FormatStr[0]), B, TLI);
|
|
|
|
// printf("%s", "a") --> putchar('a')
|
|
if (FormatStr == "%s" && CI->getNumArgOperands() > 1) {
|
|
StringRef ChrStr;
|
|
if (!getConstantStringInfo(CI->getOperand(1), ChrStr))
|
|
return nullptr;
|
|
if (ChrStr.size() != 1)
|
|
return nullptr;
|
|
return emitPutChar(B.getInt32(ChrStr[0]), B, TLI);
|
|
}
|
|
|
|
// printf("foo\n") --> puts("foo")
|
|
if (FormatStr[FormatStr.size() - 1] == '\n' &&
|
|
FormatStr.find('%') == StringRef::npos) { // No format characters.
|
|
// Create a string literal with no \n on it. We expect the constant merge
|
|
// pass to be run after this pass, to merge duplicate strings.
|
|
FormatStr = FormatStr.drop_back();
|
|
Value *GV = B.CreateGlobalString(FormatStr, "str");
|
|
return emitPutS(GV, B, TLI);
|
|
}
|
|
|
|
// Optimize specific format strings.
|
|
// printf("%c", chr) --> putchar(chr)
|
|
if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
|
|
CI->getArgOperand(1)->getType()->isIntegerTy())
|
|
return emitPutChar(CI->getArgOperand(1), B, TLI);
|
|
|
|
// printf("%s\n", str) --> puts(str)
|
|
if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
|
|
CI->getArgOperand(1)->getType()->isPointerTy())
|
|
return emitPutS(CI->getArgOperand(1), B, TLI);
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizePrintF(CallInst *CI, IRBuilder<> &B) {
|
|
|
|
Function *Callee = CI->getCalledFunction();
|
|
FunctionType *FT = Callee->getFunctionType();
|
|
if (Value *V = optimizePrintFString(CI, B)) {
|
|
return V;
|
|
}
|
|
|
|
// printf(format, ...) -> iprintf(format, ...) if no floating point
|
|
// arguments.
|
|
if (TLI->has(LibFunc::iprintf) && !callHasFloatingPointArgument(CI)) {
|
|
Module *M = B.GetInsertBlock()->getParent()->getParent();
|
|
Constant *IPrintFFn =
|
|
M->getOrInsertFunction("iprintf", FT, Callee->getAttributes());
|
|
CallInst *New = cast<CallInst>(CI->clone());
|
|
New->setCalledFunction(IPrintFFn);
|
|
B.Insert(New);
|
|
return New;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI, IRBuilder<> &B) {
|
|
// Check for a fixed format string.
|
|
StringRef FormatStr;
|
|
if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
|
|
return nullptr;
|
|
|
|
// If we just have a format string (nothing else crazy) transform it.
|
|
if (CI->getNumArgOperands() == 2) {
|
|
// Make sure there's no % in the constant array. We could try to handle
|
|
// %% -> % in the future if we cared.
|
|
for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
|
|
if (FormatStr[i] == '%')
|
|
return nullptr; // we found a format specifier, bail out.
|
|
|
|
// sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
|
|
B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
|
|
ConstantInt::get(DL.getIntPtrType(CI->getContext()),
|
|
FormatStr.size() + 1),
|
|
1); // Copy the null byte.
|
|
return ConstantInt::get(CI->getType(), FormatStr.size());
|
|
}
|
|
|
|
// The remaining optimizations require the format string to be "%s" or "%c"
|
|
// and have an extra operand.
|
|
if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
|
|
CI->getNumArgOperands() < 3)
|
|
return nullptr;
|
|
|
|
// Decode the second character of the format string.
|
|
if (FormatStr[1] == 'c') {
|
|
// sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
|
|
if (!CI->getArgOperand(2)->getType()->isIntegerTy())
|
|
return nullptr;
|
|
Value *V = B.CreateTrunc(CI->getArgOperand(2), B.getInt8Ty(), "char");
|
|
Value *Ptr = castToCStr(CI->getArgOperand(0), B);
|
|
B.CreateStore(V, Ptr);
|
|
Ptr = B.CreateGEP(B.getInt8Ty(), Ptr, B.getInt32(1), "nul");
|
|
B.CreateStore(B.getInt8(0), Ptr);
|
|
|
|
return ConstantInt::get(CI->getType(), 1);
|
|
}
|
|
|
|
if (FormatStr[1] == 's') {
|
|
// sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
|
|
if (!CI->getArgOperand(2)->getType()->isPointerTy())
|
|
return nullptr;
|
|
|
|
Value *Len = emitStrLen(CI->getArgOperand(2), B, DL, TLI);
|
|
if (!Len)
|
|
return nullptr;
|
|
Value *IncLen =
|
|
B.CreateAdd(Len, ConstantInt::get(Len->getType(), 1), "leninc");
|
|
B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(2), IncLen, 1);
|
|
|
|
// The sprintf result is the unincremented number of bytes in the string.
|
|
return B.CreateIntCast(Len, CI->getType(), false);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeSPrintF(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
FunctionType *FT = Callee->getFunctionType();
|
|
if (Value *V = optimizeSPrintFString(CI, B)) {
|
|
return V;
|
|
}
|
|
|
|
// sprintf(str, format, ...) -> siprintf(str, format, ...) if no floating
|
|
// point arguments.
|
|
if (TLI->has(LibFunc::siprintf) && !callHasFloatingPointArgument(CI)) {
|
|
Module *M = B.GetInsertBlock()->getParent()->getParent();
|
|
Constant *SIPrintFFn =
|
|
M->getOrInsertFunction("siprintf", FT, Callee->getAttributes());
|
|
CallInst *New = cast<CallInst>(CI->clone());
|
|
New->setCalledFunction(SIPrintFFn);
|
|
B.Insert(New);
|
|
return New;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeFPrintFString(CallInst *CI, IRBuilder<> &B) {
|
|
optimizeErrorReporting(CI, B, 0);
|
|
|
|
// All the optimizations depend on the format string.
|
|
StringRef FormatStr;
|
|
if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
|
|
return nullptr;
|
|
|
|
// Do not do any of the following transformations if the fprintf return
|
|
// value is used, in general the fprintf return value is not compatible
|
|
// with fwrite(), fputc() or fputs().
|
|
if (!CI->use_empty())
|
|
return nullptr;
|
|
|
|
// fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
|
|
if (CI->getNumArgOperands() == 2) {
|
|
for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
|
|
if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
|
|
return nullptr; // We found a format specifier.
|
|
|
|
return emitFWrite(
|
|
CI->getArgOperand(1),
|
|
ConstantInt::get(DL.getIntPtrType(CI->getContext()), FormatStr.size()),
|
|
CI->getArgOperand(0), B, DL, TLI);
|
|
}
|
|
|
|
// The remaining optimizations require the format string to be "%s" or "%c"
|
|
// and have an extra operand.
|
|
if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
|
|
CI->getNumArgOperands() < 3)
|
|
return nullptr;
|
|
|
|
// Decode the second character of the format string.
|
|
if (FormatStr[1] == 'c') {
|
|
// fprintf(F, "%c", chr) --> fputc(chr, F)
|
|
if (!CI->getArgOperand(2)->getType()->isIntegerTy())
|
|
return nullptr;
|
|
return emitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, TLI);
|
|
}
|
|
|
|
if (FormatStr[1] == 's') {
|
|
// fprintf(F, "%s", str) --> fputs(str, F)
|
|
if (!CI->getArgOperand(2)->getType()->isPointerTy())
|
|
return nullptr;
|
|
return emitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TLI);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeFPrintF(CallInst *CI, IRBuilder<> &B) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
FunctionType *FT = Callee->getFunctionType();
|
|
if (Value *V = optimizeFPrintFString(CI, B)) {
|
|
return V;
|
|
}
|
|
|
|
// fprintf(stream, format, ...) -> fiprintf(stream, format, ...) if no
|
|
// floating point arguments.
|
|
if (TLI->has(LibFunc::fiprintf) && !callHasFloatingPointArgument(CI)) {
|
|
Module *M = B.GetInsertBlock()->getParent()->getParent();
|
|
Constant *FIPrintFFn =
|
|
M->getOrInsertFunction("fiprintf", FT, Callee->getAttributes());
|
|
CallInst *New = cast<CallInst>(CI->clone());
|
|
New->setCalledFunction(FIPrintFFn);
|
|
B.Insert(New);
|
|
return New;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeFWrite(CallInst *CI, IRBuilder<> &B) {
|
|
optimizeErrorReporting(CI, B, 3);
|
|
|
|
// Get the element size and count.
|
|
ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
|
|
ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
|
|
if (!SizeC || !CountC)
|
|
return nullptr;
|
|
uint64_t Bytes = SizeC->getZExtValue() * CountC->getZExtValue();
|
|
|
|
// If this is writing zero records, remove the call (it's a noop).
|
|
if (Bytes == 0)
|
|
return ConstantInt::get(CI->getType(), 0);
|
|
|
|
// If this is writing one byte, turn it into fputc.
|
|
// This optimisation is only valid, if the return value is unused.
|
|
if (Bytes == 1 && CI->use_empty()) { // fwrite(S,1,1,F) -> fputc(S[0],F)
|
|
Value *Char = B.CreateLoad(castToCStr(CI->getArgOperand(0), B), "char");
|
|
Value *NewCI = emitFPutC(Char, CI->getArgOperand(3), B, TLI);
|
|
return NewCI ? ConstantInt::get(CI->getType(), 1) : nullptr;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeFPuts(CallInst *CI, IRBuilder<> &B) {
|
|
optimizeErrorReporting(CI, B, 1);
|
|
|
|
// Don't rewrite fputs to fwrite when optimising for size because fwrite
|
|
// requires more arguments and thus extra MOVs are required.
|
|
if (CI->getParent()->getParent()->optForSize())
|
|
return nullptr;
|
|
|
|
// We can't optimize if return value is used.
|
|
if (!CI->use_empty())
|
|
return nullptr;
|
|
|
|
// fputs(s,F) --> fwrite(s,1,strlen(s),F)
|
|
uint64_t Len = GetStringLength(CI->getArgOperand(0));
|
|
if (!Len)
|
|
return nullptr;
|
|
|
|
// Known to have no uses (see above).
|
|
return emitFWrite(
|
|
CI->getArgOperand(0),
|
|
ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len - 1),
|
|
CI->getArgOperand(1), B, DL, TLI);
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizePuts(CallInst *CI, IRBuilder<> &B) {
|
|
// Check for a constant string.
|
|
StringRef Str;
|
|
if (!getConstantStringInfo(CI->getArgOperand(0), Str))
|
|
return nullptr;
|
|
|
|
if (Str.empty() && CI->use_empty()) {
|
|
// puts("") -> putchar('\n')
|
|
Value *Res = emitPutChar(B.getInt32('\n'), B, TLI);
|
|
if (CI->use_empty() || !Res)
|
|
return Res;
|
|
return B.CreateIntCast(Res, CI->getType(), true);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
bool LibCallSimplifier::hasFloatVersion(StringRef FuncName) {
|
|
LibFunc::Func Func;
|
|
SmallString<20> FloatFuncName = FuncName;
|
|
FloatFuncName += 'f';
|
|
if (TLI->getLibFunc(FloatFuncName, Func))
|
|
return TLI->has(Func);
|
|
return false;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeStringMemoryLibCall(CallInst *CI,
|
|
IRBuilder<> &Builder) {
|
|
LibFunc::Func Func;
|
|
Function *Callee = CI->getCalledFunction();
|
|
// Check for string/memory library functions.
|
|
if (TLI->getLibFunc(*Callee, Func) && TLI->has(Func)) {
|
|
// Make sure we never change the calling convention.
|
|
assert((ignoreCallingConv(Func) ||
|
|
CI->getCallingConv() == llvm::CallingConv::C) &&
|
|
"Optimizing string/memory libcall would change the calling convention");
|
|
switch (Func) {
|
|
case LibFunc::strcat:
|
|
return optimizeStrCat(CI, Builder);
|
|
case LibFunc::strncat:
|
|
return optimizeStrNCat(CI, Builder);
|
|
case LibFunc::strchr:
|
|
return optimizeStrChr(CI, Builder);
|
|
case LibFunc::strrchr:
|
|
return optimizeStrRChr(CI, Builder);
|
|
case LibFunc::strcmp:
|
|
return optimizeStrCmp(CI, Builder);
|
|
case LibFunc::strncmp:
|
|
return optimizeStrNCmp(CI, Builder);
|
|
case LibFunc::strcpy:
|
|
return optimizeStrCpy(CI, Builder);
|
|
case LibFunc::stpcpy:
|
|
return optimizeStpCpy(CI, Builder);
|
|
case LibFunc::strncpy:
|
|
return optimizeStrNCpy(CI, Builder);
|
|
case LibFunc::strlen:
|
|
return optimizeStrLen(CI, Builder);
|
|
case LibFunc::strpbrk:
|
|
return optimizeStrPBrk(CI, Builder);
|
|
case LibFunc::strtol:
|
|
case LibFunc::strtod:
|
|
case LibFunc::strtof:
|
|
case LibFunc::strtoul:
|
|
case LibFunc::strtoll:
|
|
case LibFunc::strtold:
|
|
case LibFunc::strtoull:
|
|
return optimizeStrTo(CI, Builder);
|
|
case LibFunc::strspn:
|
|
return optimizeStrSpn(CI, Builder);
|
|
case LibFunc::strcspn:
|
|
return optimizeStrCSpn(CI, Builder);
|
|
case LibFunc::strstr:
|
|
return optimizeStrStr(CI, Builder);
|
|
case LibFunc::memchr:
|
|
return optimizeMemChr(CI, Builder);
|
|
case LibFunc::memcmp:
|
|
return optimizeMemCmp(CI, Builder);
|
|
case LibFunc::memcpy:
|
|
return optimizeMemCpy(CI, Builder);
|
|
case LibFunc::memmove:
|
|
return optimizeMemMove(CI, Builder);
|
|
case LibFunc::memset:
|
|
return optimizeMemSet(CI, Builder);
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *LibCallSimplifier::optimizeCall(CallInst *CI) {
|
|
if (CI->isNoBuiltin())
|
|
return nullptr;
|
|
|
|
LibFunc::Func Func;
|
|
Function *Callee = CI->getCalledFunction();
|
|
StringRef FuncName = Callee->getName();
|
|
|
|
SmallVector<OperandBundleDef, 2> OpBundles;
|
|
CI->getOperandBundlesAsDefs(OpBundles);
|
|
IRBuilder<> Builder(CI, /*FPMathTag=*/nullptr, OpBundles);
|
|
bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
|
|
|
|
// Command-line parameter overrides instruction attribute.
|
|
if (EnableUnsafeFPShrink.getNumOccurrences() > 0)
|
|
UnsafeFPShrink = EnableUnsafeFPShrink;
|
|
else if (isa<FPMathOperator>(CI) && CI->hasUnsafeAlgebra())
|
|
UnsafeFPShrink = true;
|
|
|
|
// First, check for intrinsics.
|
|
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI)) {
|
|
if (!isCallingConvC)
|
|
return nullptr;
|
|
switch (II->getIntrinsicID()) {
|
|
case Intrinsic::pow:
|
|
return optimizePow(CI, Builder);
|
|
case Intrinsic::exp2:
|
|
return optimizeExp2(CI, Builder);
|
|
case Intrinsic::fabs:
|
|
return optimizeFabs(CI, Builder);
|
|
case Intrinsic::log:
|
|
return optimizeLog(CI, Builder);
|
|
case Intrinsic::sqrt:
|
|
return optimizeSqrt(CI, Builder);
|
|
// TODO: Use foldMallocMemset() with memset intrinsic.
|
|
default:
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
// Also try to simplify calls to fortified library functions.
|
|
if (Value *SimplifiedFortifiedCI = FortifiedSimplifier.optimizeCall(CI)) {
|
|
// Try to further simplify the result.
|
|
CallInst *SimplifiedCI = dyn_cast<CallInst>(SimplifiedFortifiedCI);
|
|
if (SimplifiedCI && SimplifiedCI->getCalledFunction()) {
|
|
// Use an IR Builder from SimplifiedCI if available instead of CI
|
|
// to guarantee we reach all uses we might replace later on.
|
|
IRBuilder<> TmpBuilder(SimplifiedCI);
|
|
if (Value *V = optimizeStringMemoryLibCall(SimplifiedCI, TmpBuilder)) {
|
|
// If we were able to further simplify, remove the now redundant call.
|
|
SimplifiedCI->replaceAllUsesWith(V);
|
|
SimplifiedCI->eraseFromParent();
|
|
return V;
|
|
}
|
|
}
|
|
return SimplifiedFortifiedCI;
|
|
}
|
|
|
|
// Then check for known library functions.
|
|
if (TLI->getLibFunc(*Callee, Func) && TLI->has(Func)) {
|
|
// We never change the calling convention.
|
|
if (!ignoreCallingConv(Func) && !isCallingConvC)
|
|
return nullptr;
|
|
if (Value *V = optimizeStringMemoryLibCall(CI, Builder))
|
|
return V;
|
|
switch (Func) {
|
|
case LibFunc::cosf:
|
|
case LibFunc::cos:
|
|
case LibFunc::cosl:
|
|
return optimizeCos(CI, Builder);
|
|
case LibFunc::sinpif:
|
|
case LibFunc::sinpi:
|
|
case LibFunc::cospif:
|
|
case LibFunc::cospi:
|
|
return optimizeSinCosPi(CI, Builder);
|
|
case LibFunc::powf:
|
|
case LibFunc::pow:
|
|
case LibFunc::powl:
|
|
return optimizePow(CI, Builder);
|
|
case LibFunc::exp2l:
|
|
case LibFunc::exp2:
|
|
case LibFunc::exp2f:
|
|
return optimizeExp2(CI, Builder);
|
|
case LibFunc::fabsf:
|
|
case LibFunc::fabs:
|
|
case LibFunc::fabsl:
|
|
return optimizeFabs(CI, Builder);
|
|
case LibFunc::sqrtf:
|
|
case LibFunc::sqrt:
|
|
case LibFunc::sqrtl:
|
|
return optimizeSqrt(CI, Builder);
|
|
case LibFunc::ffs:
|
|
case LibFunc::ffsl:
|
|
case LibFunc::ffsll:
|
|
return optimizeFFS(CI, Builder);
|
|
case LibFunc::abs:
|
|
case LibFunc::labs:
|
|
case LibFunc::llabs:
|
|
return optimizeAbs(CI, Builder);
|
|
case LibFunc::isdigit:
|
|
return optimizeIsDigit(CI, Builder);
|
|
case LibFunc::isascii:
|
|
return optimizeIsAscii(CI, Builder);
|
|
case LibFunc::toascii:
|
|
return optimizeToAscii(CI, Builder);
|
|
case LibFunc::printf:
|
|
return optimizePrintF(CI, Builder);
|
|
case LibFunc::sprintf:
|
|
return optimizeSPrintF(CI, Builder);
|
|
case LibFunc::fprintf:
|
|
return optimizeFPrintF(CI, Builder);
|
|
case LibFunc::fwrite:
|
|
return optimizeFWrite(CI, Builder);
|
|
case LibFunc::fputs:
|
|
return optimizeFPuts(CI, Builder);
|
|
case LibFunc::log:
|
|
case LibFunc::log10:
|
|
case LibFunc::log1p:
|
|
case LibFunc::log2:
|
|
case LibFunc::logb:
|
|
return optimizeLog(CI, Builder);
|
|
case LibFunc::puts:
|
|
return optimizePuts(CI, Builder);
|
|
case LibFunc::tan:
|
|
case LibFunc::tanf:
|
|
case LibFunc::tanl:
|
|
return optimizeTan(CI, Builder);
|
|
case LibFunc::perror:
|
|
return optimizeErrorReporting(CI, Builder);
|
|
case LibFunc::vfprintf:
|
|
case LibFunc::fiprintf:
|
|
return optimizeErrorReporting(CI, Builder, 0);
|
|
case LibFunc::fputc:
|
|
return optimizeErrorReporting(CI, Builder, 1);
|
|
case LibFunc::ceil:
|
|
case LibFunc::floor:
|
|
case LibFunc::rint:
|
|
case LibFunc::round:
|
|
case LibFunc::nearbyint:
|
|
case LibFunc::trunc:
|
|
if (hasFloatVersion(FuncName))
|
|
return optimizeUnaryDoubleFP(CI, Builder, false);
|
|
return nullptr;
|
|
case LibFunc::acos:
|
|
case LibFunc::acosh:
|
|
case LibFunc::asin:
|
|
case LibFunc::asinh:
|
|
case LibFunc::atan:
|
|
case LibFunc::atanh:
|
|
case LibFunc::cbrt:
|
|
case LibFunc::cosh:
|
|
case LibFunc::exp:
|
|
case LibFunc::exp10:
|
|
case LibFunc::expm1:
|
|
case LibFunc::sin:
|
|
case LibFunc::sinh:
|
|
case LibFunc::tanh:
|
|
if (UnsafeFPShrink && hasFloatVersion(FuncName))
|
|
return optimizeUnaryDoubleFP(CI, Builder, true);
|
|
return nullptr;
|
|
case LibFunc::copysign:
|
|
if (hasFloatVersion(FuncName))
|
|
return optimizeBinaryDoubleFP(CI, Builder);
|
|
return nullptr;
|
|
case LibFunc::fminf:
|
|
case LibFunc::fmin:
|
|
case LibFunc::fminl:
|
|
case LibFunc::fmaxf:
|
|
case LibFunc::fmax:
|
|
case LibFunc::fmaxl:
|
|
return optimizeFMinFMax(CI, Builder);
|
|
default:
|
|
return nullptr;
|
|
}
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
LibCallSimplifier::LibCallSimplifier(
|
|
const DataLayout &DL, const TargetLibraryInfo *TLI,
|
|
function_ref<void(Instruction *, Value *)> Replacer)
|
|
: FortifiedSimplifier(TLI), DL(DL), TLI(TLI), UnsafeFPShrink(false),
|
|
Replacer(Replacer) {}
|
|
|
|
void LibCallSimplifier::replaceAllUsesWith(Instruction *I, Value *With) {
|
|
// Indirect through the replacer used in this instance.
|
|
Replacer(I, With);
|
|
}
|
|
|
|
// TODO:
|
|
// Additional cases that we need to add to this file:
|
|
//
|
|
// cbrt:
|
|
// * cbrt(expN(X)) -> expN(x/3)
|
|
// * cbrt(sqrt(x)) -> pow(x,1/6)
|
|
// * cbrt(cbrt(x)) -> pow(x,1/9)
|
|
//
|
|
// exp, expf, expl:
|
|
// * exp(log(x)) -> x
|
|
//
|
|
// log, logf, logl:
|
|
// * log(exp(x)) -> x
|
|
// * log(exp(y)) -> y*log(e)
|
|
// * log(exp10(y)) -> y*log(10)
|
|
// * log(sqrt(x)) -> 0.5*log(x)
|
|
//
|
|
// lround, lroundf, lroundl:
|
|
// * lround(cnst) -> cnst'
|
|
//
|
|
// pow, powf, powl:
|
|
// * pow(sqrt(x),y) -> pow(x,y*0.5)
|
|
// * pow(pow(x,y),z)-> pow(x,y*z)
|
|
//
|
|
// round, roundf, roundl:
|
|
// * round(cnst) -> cnst'
|
|
//
|
|
// signbit:
|
|
// * signbit(cnst) -> cnst'
|
|
// * signbit(nncst) -> 0 (if pstv is a non-negative constant)
|
|
//
|
|
// sqrt, sqrtf, sqrtl:
|
|
// * sqrt(expN(x)) -> expN(x*0.5)
|
|
// * sqrt(Nroot(x)) -> pow(x,1/(2*N))
|
|
// * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
|
|
//
|
|
// trunc, truncf, truncl:
|
|
// * trunc(cnst) -> cnst'
|
|
//
|
|
//
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Fortified Library Call Optimizations
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
bool FortifiedLibCallSimplifier::isFortifiedCallFoldable(CallInst *CI,
|
|
unsigned ObjSizeOp,
|
|
unsigned SizeOp,
|
|
bool isString) {
|
|
if (CI->getArgOperand(ObjSizeOp) == CI->getArgOperand(SizeOp))
|
|
return true;
|
|
if (ConstantInt *ObjSizeCI =
|
|
dyn_cast<ConstantInt>(CI->getArgOperand(ObjSizeOp))) {
|
|
if (ObjSizeCI->isAllOnesValue())
|
|
return true;
|
|
// If the object size wasn't -1 (unknown), bail out if we were asked to.
|
|
if (OnlyLowerUnknownSize)
|
|
return false;
|
|
if (isString) {
|
|
uint64_t Len = GetStringLength(CI->getArgOperand(SizeOp));
|
|
// If the length is 0 we don't know how long it is and so we can't
|
|
// remove the check.
|
|
if (Len == 0)
|
|
return false;
|
|
return ObjSizeCI->getZExtValue() >= Len;
|
|
}
|
|
if (ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getArgOperand(SizeOp)))
|
|
return ObjSizeCI->getZExtValue() >= SizeCI->getZExtValue();
|
|
}
|
|
return false;
|
|
}
|
|
|
|
Value *FortifiedLibCallSimplifier::optimizeMemCpyChk(CallInst *CI,
|
|
IRBuilder<> &B) {
|
|
if (isFortifiedCallFoldable(CI, 3, 2, false)) {
|
|
B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
|
|
CI->getArgOperand(2), 1);
|
|
return CI->getArgOperand(0);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *FortifiedLibCallSimplifier::optimizeMemMoveChk(CallInst *CI,
|
|
IRBuilder<> &B) {
|
|
if (isFortifiedCallFoldable(CI, 3, 2, false)) {
|
|
B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
|
|
CI->getArgOperand(2), 1);
|
|
return CI->getArgOperand(0);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *FortifiedLibCallSimplifier::optimizeMemSetChk(CallInst *CI,
|
|
IRBuilder<> &B) {
|
|
// TODO: Try foldMallocMemset() here.
|
|
|
|
if (isFortifiedCallFoldable(CI, 3, 2, false)) {
|
|
Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
|
|
B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
|
|
return CI->getArgOperand(0);
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *FortifiedLibCallSimplifier::optimizeStrpCpyChk(CallInst *CI,
|
|
IRBuilder<> &B,
|
|
LibFunc::Func Func) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
StringRef Name = Callee->getName();
|
|
const DataLayout &DL = CI->getModule()->getDataLayout();
|
|
Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1),
|
|
*ObjSize = CI->getArgOperand(2);
|
|
|
|
// __stpcpy_chk(x,x,...) -> x+strlen(x)
|
|
if (Func == LibFunc::stpcpy_chk && !OnlyLowerUnknownSize && Dst == Src) {
|
|
Value *StrLen = emitStrLen(Src, B, DL, TLI);
|
|
return StrLen ? B.CreateInBoundsGEP(B.getInt8Ty(), Dst, StrLen) : nullptr;
|
|
}
|
|
|
|
// If a) we don't have any length information, or b) we know this will
|
|
// fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
|
|
// st[rp]cpy_chk call which may fail at runtime if the size is too long.
|
|
// TODO: It might be nice to get a maximum length out of the possible
|
|
// string lengths for varying.
|
|
if (isFortifiedCallFoldable(CI, 2, 1, true))
|
|
return emitStrCpy(Dst, Src, B, TLI, Name.substr(2, 6));
|
|
|
|
if (OnlyLowerUnknownSize)
|
|
return nullptr;
|
|
|
|
// Maybe we can stil fold __st[rp]cpy_chk to __memcpy_chk.
|
|
uint64_t Len = GetStringLength(Src);
|
|
if (Len == 0)
|
|
return nullptr;
|
|
|
|
Type *SizeTTy = DL.getIntPtrType(CI->getContext());
|
|
Value *LenV = ConstantInt::get(SizeTTy, Len);
|
|
Value *Ret = emitMemCpyChk(Dst, Src, LenV, ObjSize, B, DL, TLI);
|
|
// If the function was an __stpcpy_chk, and we were able to fold it into
|
|
// a __memcpy_chk, we still need to return the correct end pointer.
|
|
if (Ret && Func == LibFunc::stpcpy_chk)
|
|
return B.CreateGEP(B.getInt8Ty(), Dst, ConstantInt::get(SizeTTy, Len - 1));
|
|
return Ret;
|
|
}
|
|
|
|
Value *FortifiedLibCallSimplifier::optimizeStrpNCpyChk(CallInst *CI,
|
|
IRBuilder<> &B,
|
|
LibFunc::Func Func) {
|
|
Function *Callee = CI->getCalledFunction();
|
|
StringRef Name = Callee->getName();
|
|
if (isFortifiedCallFoldable(CI, 3, 2, false)) {
|
|
Value *Ret = emitStrNCpy(CI->getArgOperand(0), CI->getArgOperand(1),
|
|
CI->getArgOperand(2), B, TLI, Name.substr(2, 7));
|
|
return Ret;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Value *FortifiedLibCallSimplifier::optimizeCall(CallInst *CI) {
|
|
// FIXME: We shouldn't be changing "nobuiltin" or TLI unavailable calls here.
|
|
// Some clang users checked for _chk libcall availability using:
|
|
// __has_builtin(__builtin___memcpy_chk)
|
|
// When compiling with -fno-builtin, this is always true.
|
|
// When passing -ffreestanding/-mkernel, which both imply -fno-builtin, we
|
|
// end up with fortified libcalls, which isn't acceptable in a freestanding
|
|
// environment which only provides their non-fortified counterparts.
|
|
//
|
|
// Until we change clang and/or teach external users to check for availability
|
|
// differently, disregard the "nobuiltin" attribute and TLI::has.
|
|
//
|
|
// PR23093.
|
|
|
|
LibFunc::Func Func;
|
|
Function *Callee = CI->getCalledFunction();
|
|
|
|
SmallVector<OperandBundleDef, 2> OpBundles;
|
|
CI->getOperandBundlesAsDefs(OpBundles);
|
|
IRBuilder<> Builder(CI, /*FPMathTag=*/nullptr, OpBundles);
|
|
bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
|
|
|
|
// First, check that this is a known library functions and that the prototype
|
|
// is correct.
|
|
if (!TLI->getLibFunc(*Callee, Func))
|
|
return nullptr;
|
|
|
|
// We never change the calling convention.
|
|
if (!ignoreCallingConv(Func) && !isCallingConvC)
|
|
return nullptr;
|
|
|
|
switch (Func) {
|
|
case LibFunc::memcpy_chk:
|
|
return optimizeMemCpyChk(CI, Builder);
|
|
case LibFunc::memmove_chk:
|
|
return optimizeMemMoveChk(CI, Builder);
|
|
case LibFunc::memset_chk:
|
|
return optimizeMemSetChk(CI, Builder);
|
|
case LibFunc::stpcpy_chk:
|
|
case LibFunc::strcpy_chk:
|
|
return optimizeStrpCpyChk(CI, Builder, Func);
|
|
case LibFunc::stpncpy_chk:
|
|
case LibFunc::strncpy_chk:
|
|
return optimizeStrpNCpyChk(CI, Builder, Func);
|
|
default:
|
|
break;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
FortifiedLibCallSimplifier::FortifiedLibCallSimplifier(
|
|
const TargetLibraryInfo *TLI, bool OnlyLowerUnknownSize)
|
|
: TLI(TLI), OnlyLowerUnknownSize(OnlyLowerUnknownSize) {}
|