#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/CommandLine.h"
-#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
+#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
using namespace PatternMatch;
ColdErrorCalls("error-reporting-is-cold", cl::init(true), cl::Hidden,
cl::desc("Treat error-reporting calls as cold"));
+static cl::opt<bool>
+ EnableUnsafeFPShrink("enable-double-float-shrink", cl::Hidden,
+ cl::init(false),
+ cl::desc("Enable unsafe double to float "
+ "shrinking for math lib calls"));
+
+
//===----------------------------------------------------------------------===//
// Helper Functions
//===----------------------------------------------------------------------===//
static bool ignoreCallingConv(LibFunc::Func Func) {
- switch (Func) {
- case LibFunc::abs:
- case LibFunc::labs:
- case LibFunc::llabs:
- case LibFunc::strlen:
- return true;
- default:
- return false;
- }
- llvm_unreachable("All cases should be covered in the switch.");
+ return Func == LibFunc::abs || Func == LibFunc::labs ||
+ Func == LibFunc::llabs || Func == LibFunc::strlen;
}
/// isOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
}
static bool callHasFloatingPointArgument(const CallInst *CI) {
- for (CallInst::const_op_iterator it = CI->op_begin(), e = CI->op_end();
- it != e; ++it) {
- if ((*it)->getType()->isFloatingPointTy())
- return true;
- }
- return false;
+ return std::any_of(CI->op_begin(), CI->op_end(), [](const Use &OI) {
+ return OI->getType()->isFloatingPointTy();
+ });
}
/// \brief Check whether the overloaded unary floating point function
-/// corresponing to \a Ty is available.
+/// corresponding to \a Ty is available.
static bool hasUnaryFloatFn(const TargetLibraryInfo *TLI, Type *Ty,
LibFunc::Func DoubleFn, LibFunc::Func FloatFn,
LibFunc::Func LongDoubleFn) {
}
}
-//===----------------------------------------------------------------------===//
-// Fortified Library Call Optimizations
-//===----------------------------------------------------------------------===//
+/// \brief Check whether we can use unsafe floating point math for
+/// the function passed as input.
+static bool canUseUnsafeFPMath(Function *F) {
-static bool isFortifiedCallFoldable(CallInst *CI, unsigned SizeCIOp, unsigned SizeArgOp,
- bool isString) {
- if (CI->getArgOperand(SizeCIOp) == CI->getArgOperand(SizeArgOp))
- return true;
- if (ConstantInt *SizeCI =
- dyn_cast<ConstantInt>(CI->getArgOperand(SizeCIOp))) {
- if (SizeCI->isAllOnesValue())
+ // FIXME: For finer-grain optimization, we need intrinsics to have the same
+ // fast-math flag decorations that are applied to FP instructions. For now,
+ // we have to rely on the function-level unsafe-fp-math attribute to do this
+ // optimization because there's no other way to express that the call can be
+ // relaxed.
+ if (F->hasFnAttribute("unsafe-fp-math")) {
+ Attribute Attr = F->getFnAttribute("unsafe-fp-math");
+ if (Attr.getValueAsString() == "true")
return true;
- if (isString) {
- uint64_t Len = GetStringLength(CI->getArgOperand(SizeArgOp));
- // 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 SizeCI->getZExtValue() >= Len;
- }
- if (ConstantInt *Arg = dyn_cast<ConstantInt>(CI->getArgOperand(SizeArgOp)))
- return SizeCI->getZExtValue() >= Arg->getZExtValue();
}
return false;
}
-Value *LibCallSimplifier::optimizeMemCpyChk(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- LLVMContext &Context = CI->getContext();
-
- // Check if this has the right signature.
- if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isPointerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(Context) ||
- FT->getParamType(3) != DL->getIntPtrType(Context))
- return nullptr;
-
- 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 *LibCallSimplifier::optimizeMemMoveChk(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- LLVMContext &Context = CI->getContext();
-
- // Check if this has the right signature.
- if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isPointerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(Context) ||
- FT->getParamType(3) != DL->getIntPtrType(Context))
- return nullptr;
-
- 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 *LibCallSimplifier::optimizeMemSetChk(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- LLVMContext &Context = CI->getContext();
-
- // Check if this has the right signature.
- if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isIntegerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(Context) ||
- FT->getParamType(3) != DL->getIntPtrType(Context))
- return nullptr;
-
- 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 *LibCallSimplifier::optimizeStrCpyChk(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- StringRef Name = Callee->getName();
- FunctionType *FT = Callee->getFunctionType();
- LLVMContext &Context = CI->getContext();
-
- // Check if this has the right signature.
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
- FT->getParamType(2) != DL->getIntPtrType(Context))
- return nullptr;
-
- Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
- if (Dst == Src) // __strcpy_chk(x,x) -> x
- return Src;
-
- // If a) we don't have any length information, or b) we know this will
- // fit then just lower to a plain strcpy. Otherwise we'll keep our
- // strcpy_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)) {
- Value *Ret = EmitStrCpy(Dst, Src, B, DL, TLI, Name.substr(2, 6));
- return Ret;
- } else {
- // Maybe we can stil fold __strcpy_chk to __memcpy_chk.
- uint64_t Len = GetStringLength(Src);
- if (Len == 0)
- return nullptr;
-
- // This optimization require DataLayout.
- if (!DL)
- return nullptr;
-
- Value *Ret = EmitMemCpyChk(
- Dst, Src, ConstantInt::get(DL->getIntPtrType(Context), Len),
- CI->getArgOperand(2), B, DL, TLI);
- return Ret;
- }
- return nullptr;
-}
-
-Value *LibCallSimplifier::optimizeStpCpyChk(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- StringRef Name = Callee->getName();
- FunctionType *FT = Callee->getFunctionType();
- LLVMContext &Context = CI->getContext();
-
- // Check if this has the right signature.
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
- FT->getParamType(2) != DL->getIntPtrType(FT->getParamType(0)))
- return nullptr;
-
- Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
- if (Dst == Src) { // stpcpy(x,x) -> x+strlen(x)
- Value *StrLen = EmitStrLen(Src, B, DL, TLI);
- return StrLen ? B.CreateInBoundsGEP(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 stpcpy. Otherwise we'll keep our
- // stpcpy_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)) {
- Value *Ret = EmitStrCpy(Dst, Src, B, DL, TLI, Name.substr(2, 6));
- return Ret;
- } else {
- // Maybe we can stil fold __stpcpy_chk to __memcpy_chk.
- uint64_t Len = GetStringLength(Src);
- if (Len == 0)
- return nullptr;
-
- // This optimization require DataLayout.
- if (!DL)
- return nullptr;
-
- Type *PT = FT->getParamType(0);
- Value *LenV = ConstantInt::get(DL->getIntPtrType(PT), Len);
- Value *DstEnd =
- B.CreateGEP(Dst, ConstantInt::get(DL->getIntPtrType(PT), Len - 1));
- if (!EmitMemCpyChk(Dst, Src, LenV, CI->getArgOperand(2), B, DL, TLI))
- return nullptr;
- return DstEnd;
- }
- return nullptr;
-}
-
-Value *LibCallSimplifier::optimizeStrNCpyChk(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- StringRef Name = Callee->getName();
- FunctionType *FT = Callee->getFunctionType();
- LLVMContext &Context = CI->getContext();
-
- // Check if this has the right signature.
- if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
- !FT->getParamType(2)->isIntegerTy() ||
- FT->getParamType(3) != DL->getIntPtrType(Context))
- return nullptr;
+/// \brief Returns whether \p F matches the signature expected for the
+/// string/memory copying library function \p Func.
+/// Acceptable functions are st[rp][n]?cpy, memove, memcpy, and memset.
+/// Their fortified (_chk) counterparts are also accepted.
+static bool checkStringCopyLibFuncSignature(Function *F, LibFunc::Func Func) {
+ const DataLayout &DL = F->getParent()->getDataLayout();
+ FunctionType *FT = F->getFunctionType();
+ LLVMContext &Context = F->getContext();
+ Type *PCharTy = Type::getInt8PtrTy(Context);
+ Type *SizeTTy = DL.getIntPtrType(Context);
+ unsigned NumParams = FT->getNumParams();
+
+ // All string libfuncs return the same type as the first parameter.
+ if (FT->getReturnType() != FT->getParamType(0))
+ return false;
- if (isFortifiedCallFoldable(CI, 3, 2, false)) {
- Value *Ret =
- EmitStrNCpy(CI->getArgOperand(0), CI->getArgOperand(1),
- CI->getArgOperand(2), B, DL, TLI, Name.substr(2, 7));
- return Ret;
- }
- return nullptr;
+ switch (Func) {
+ default:
+ llvm_unreachable("Can't check signature for non-string-copy libfunc.");
+ case LibFunc::stpncpy_chk:
+ case LibFunc::strncpy_chk:
+ --NumParams; // fallthrough
+ case LibFunc::stpncpy:
+ case LibFunc::strncpy: {
+ if (NumParams != 3 || FT->getParamType(0) != FT->getParamType(1) ||
+ FT->getParamType(0) != PCharTy || !FT->getParamType(2)->isIntegerTy())
+ return false;
+ break;
+ }
+ case LibFunc::strcpy_chk:
+ case LibFunc::stpcpy_chk:
+ --NumParams; // fallthrough
+ case LibFunc::stpcpy:
+ case LibFunc::strcpy: {
+ if (NumParams != 2 || FT->getParamType(0) != FT->getParamType(1) ||
+ FT->getParamType(0) != PCharTy)
+ return false;
+ break;
+ }
+ case LibFunc::memmove_chk:
+ case LibFunc::memcpy_chk:
+ --NumParams; // fallthrough
+ case LibFunc::memmove:
+ case LibFunc::memcpy: {
+ if (NumParams != 3 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isPointerTy() || FT->getParamType(2) != SizeTTy)
+ return false;
+ break;
+ }
+ case LibFunc::memset_chk:
+ --NumParams; // fallthrough
+ case LibFunc::memset: {
+ if (NumParams != 3 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isIntegerTy() || FT->getParamType(2) != SizeTTy)
+ return false;
+ break;
+ }
+ }
+ // If this is a fortified libcall, the last parameter is a size_t.
+ if (NumParams == FT->getNumParams() - 1)
+ return FT->getParamType(FT->getNumParams() - 1) == SizeTTy;
+ return true;
}
//===----------------------------------------------------------------------===//
if (Len == 0)
return Dst;
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
return emitStrLenMemCpy(Src, Dst, Len, B);
}
// Now that we have the destination's length, we must index into the
// destination's pointer to get the actual memcpy destination (end of
// the string .. we're concatenating).
- Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
+ Value *CpyDst = B.CreateGEP(B.getInt8Ty(), Dst, DstLen, "endptr");
// We have enough information to now generate the memcpy call to do the
// concatenation for us. Make a memcpy to copy the nul byte with align = 1.
- B.CreateMemCpy(
- CpyDst, Src,
- ConstantInt::get(DL->getIntPtrType(Src->getContext()), Len + 1), 1);
+ B.CreateMemCpy(CpyDst, Src,
+ ConstantInt::get(DL.getIntPtrType(Src->getContext()), Len + 1),
+ 1);
return Dst;
}
if (SrcLen == 0 || Len == 0)
return Dst;
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
// We don't optimize this case
if (Len < SrcLen)
return nullptr;
// of the input string and turn this into memchr.
ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
if (!CharC) {
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
uint64_t Len = GetStringLength(SrcStr);
if (Len == 0 || !FT->getParamType(1)->isIntegerTy(32)) // memchr needs i32.
return nullptr;
- return EmitMemChr(
- SrcStr, CI->getArgOperand(1), // include nul.
- ConstantInt::get(DL->getIntPtrType(CI->getContext()), Len), B, DL, TLI);
+ return EmitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
+ ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len),
+ B, DL, TLI);
}
// Otherwise, the character is a constant, see if the first argument is
// a string literal. If so, we can constant fold.
StringRef Str;
if (!getConstantStringInfo(SrcStr, Str)) {
- if (DL && CharC->isZero()) // strchr(p, 0) -> p + strlen(p)
- return B.CreateGEP(SrcStr, EmitStrLen(SrcStr, B, DL, TLI), "strchr");
+ if (CharC->isZero()) // strchr(p, 0) -> p + strlen(p)
+ return B.CreateGEP(B.getInt8Ty(), SrcStr, EmitStrLen(SrcStr, B, DL, TLI), "strchr");
return nullptr;
}
return Constant::getNullValue(CI->getType());
// strchr(s+n,c) -> gep(s+n+i,c)
- return B.CreateGEP(SrcStr, B.getInt64(I), "strchr");
+ return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "strchr");
}
Value *LibCallSimplifier::optimizeStrRChr(CallInst *CI, IRBuilder<> &B) {
StringRef Str;
if (!getConstantStringInfo(SrcStr, Str)) {
// strrchr(s, 0) -> strchr(s, 0)
- if (DL && CharC->isZero())
- return EmitStrChr(SrcStr, '\0', B, DL, TLI);
+ if (CharC->isZero())
+ return EmitStrChr(SrcStr, '\0', B, TLI);
return nullptr;
}
return Constant::getNullValue(CI->getType());
// strrchr(s+n,c) -> gep(s+n+i,c)
- return B.CreateGEP(SrcStr, B.getInt64(I), "strrchr");
+ return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "strrchr");
}
Value *LibCallSimplifier::optimizeStrCmp(CallInst *CI, IRBuilder<> &B) {
uint64_t Len1 = GetStringLength(Str1P);
uint64_t Len2 = GetStringLength(Str2P);
if (Len1 && Len2) {
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
return EmitMemCmp(Str1P, Str2P,
- ConstantInt::get(DL->getIntPtrType(CI->getContext()),
+ ConstantInt::get(DL.getIntPtrType(CI->getContext()),
std::min(Len1, Len2)),
B, DL, TLI);
}
if (Length == 0) // strncmp(x,y,0) -> 0
return ConstantInt::get(CI->getType(), 0);
- if (DL && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
+ if (Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, DL, TLI);
StringRef Str1, Str2;
Value *LibCallSimplifier::optimizeStrCpy(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- // Verify the "strcpy" function prototype.
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != B.getInt8PtrTy())
+
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::strcpy))
return nullptr;
Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
if (Dst == Src) // strcpy(x,x) -> x
return Src;
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
// See if we can get the length of the input string.
uint64_t Len = GetStringLength(Src);
if (Len == 0)
// We have enough information to now generate the memcpy call to do the
// copy for us. Make a memcpy to copy the nul byte with align = 1.
B.CreateMemCpy(Dst, Src,
- ConstantInt::get(DL->getIntPtrType(CI->getContext()), Len), 1);
+ ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len), 1);
return Dst;
}
Value *LibCallSimplifier::optimizeStpCpy(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- // Verify the "stpcpy" function prototype.
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != B.getInt8PtrTy())
- return nullptr;
-
- // These optimizations require DataLayout.
- if (!DL)
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::stpcpy))
return nullptr;
Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
if (Dst == Src) { // stpcpy(x,x) -> x+strlen(x)
Value *StrLen = EmitStrLen(Src, B, DL, TLI);
- return StrLen ? B.CreateInBoundsGEP(Dst, StrLen) : nullptr;
+ return StrLen ? B.CreateInBoundsGEP(B.getInt8Ty(), Dst, StrLen) : nullptr;
}
// See if we can get the length of the input string.
if (Len == 0)
return nullptr;
- Type *PT = FT->getParamType(0);
- Value *LenV = ConstantInt::get(DL->getIntPtrType(PT), Len);
+ Type *PT = Callee->getFunctionType()->getParamType(0);
+ Value *LenV = ConstantInt::get(DL.getIntPtrType(PT), Len);
Value *DstEnd =
- B.CreateGEP(Dst, ConstantInt::get(DL->getIntPtrType(PT), Len - 1));
+ B.CreateGEP(B.getInt8Ty(), Dst, ConstantInt::get(DL.getIntPtrType(PT), Len - 1));
// We have enough information to now generate the memcpy call to do the
// copy for us. Make a memcpy to copy the nul byte with align = 1.
Value *LibCallSimplifier::optimizeStrNCpy(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- FT->getParamType(0) != FT->getParamType(1) ||
- FT->getParamType(0) != B.getInt8PtrTy() ||
- !FT->getParamType(2)->isIntegerTy())
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::strncpy))
return nullptr;
Value *Dst = CI->getArgOperand(0);
if (Len == 0)
return Dst; // strncpy(x, y, 0) -> x
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
// Let strncpy handle the zero padding
if (Len > SrcLen + 1)
return nullptr;
- Type *PT = FT->getParamType(0);
+ Type *PT = Callee->getFunctionType()->getParamType(0);
// strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
- B.CreateMemCpy(Dst, Src, ConstantInt::get(DL->getIntPtrType(PT), Len), 1);
+ B.CreateMemCpy(Dst, Src, ConstantInt::get(DL.getIntPtrType(PT), Len), 1);
return Dst;
}
bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
- // strpbrk(s, "") -> NULL
- // strpbrk("", s) -> NULL
+ // strpbrk(s, "") -> nullptr
+ // strpbrk("", s) -> nullptr
if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
return Constant::getNullValue(CI->getType());
if (I == StringRef::npos) // No match.
return Constant::getNullValue(CI->getType());
- return B.CreateGEP(CI->getArgOperand(0), B.getInt64(I), "strpbrk");
+ return B.CreateGEP(B.getInt8Ty(), CI->getArgOperand(0), B.getInt64(I), "strpbrk");
}
// strpbrk(s, "a") -> strchr(s, 'a')
- if (DL && HasS2 && S2.size() == 1)
- return EmitStrChr(CI->getArgOperand(0), S2[0], B, DL, TLI);
+ if (HasS2 && S2.size() == 1)
+ return EmitStrChr(CI->getArgOperand(0), S2[0], B, TLI);
return nullptr;
}
}
// strcspn(s, "") -> strlen(s)
- if (DL && HasS2 && S2.empty())
+ if (HasS2 && S2.empty())
return EmitStrLen(CI->getArgOperand(0), B, DL, TLI);
return nullptr;
return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
// fold strstr(a, b) == a -> strncmp(a, b, strlen(b)) == 0
- if (DL && isOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
+ if (isOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
Value *StrLen = EmitStrLen(CI->getArgOperand(1), B, DL, TLI);
if (!StrLen)
return nullptr;
// fold strstr(x, "y") -> strchr(x, 'y').
if (HasStr2 && ToFindStr.size() == 1) {
- Value *StrChr = EmitStrChr(CI->getArgOperand(0), ToFindStr[0], B, DL, TLI);
+ 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) {
+ Function *Callee = CI->getCalledFunction();
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() ||
+ !FT->getParamType(1)->isIntegerTy(32) ||
+ !FT->getParamType(2)->isIntegerTy() ||
+ !FT->getReturnType()->isPointerTy())
+ return nullptr;
+
+ 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) {
Function *Callee = CI->getCalledFunction();
FunctionType *FT = Callee->getFunctionType();
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) &&
Value *LibCallSimplifier::optimizeMemCpy(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isPointerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(CI->getContext()))
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memcpy))
return nullptr;
// memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
Value *LibCallSimplifier::optimizeMemMove(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isPointerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(CI->getContext()))
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memmove))
return nullptr;
// memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
Value *LibCallSimplifier::optimizeMemSet(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
- FunctionType *FT = Callee->getFunctionType();
- if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isPointerTy() ||
- !FT->getParamType(1)->isIntegerTy() ||
- FT->getParamType(2) != DL->getIntPtrType(FT->getParamType(0)))
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memset))
return nullptr;
// memset(p, v, n) -> llvm.memset(p, v, n, 1)
// 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;
+}
+
//===----------------------------------------------------------------------===//
// Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
}
// If this is something like 'floor((double)floatval)', convert to floorf.
- FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getArgOperand(0));
- if (!Cast || !Cast->getOperand(0)->getType()->isFloatTy())
+ Value *V = valueHasFloatPrecision(CI->getArgOperand(0));
+ if (V == nullptr)
return nullptr;
// floor((double)floatval) -> (double)floorf(floatval)
- Value *V = Cast->getOperand(0);
- V = EmitUnaryFloatFnCall(V, Callee->getName(), B, Callee->getAttributes());
+ if (Callee->isIntrinsic()) {
+ Module *M = CI->getParent()->getParent()->getParent();
+ 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());
}
return nullptr;
// If this is something like 'fmin((double)floatval1, (double)floatval2)',
- // we convert it to fminf.
- FPExtInst *Cast1 = dyn_cast<FPExtInst>(CI->getArgOperand(0));
- FPExtInst *Cast2 = dyn_cast<FPExtInst>(CI->getArgOperand(1));
- if (!Cast1 || !Cast1->getOperand(0)->getType()->isFloatTy() || !Cast2 ||
- !Cast2->getOperand(0)->getType()->isFloatTy())
+ // 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;
// fmin((double)floatval1, (double)floatval2)
- // -> (double)fmin(floatval1, floatval2)
- Value *V = nullptr;
- Value *V1 = Cast1->getOperand(0);
- Value *V2 = Cast2->getOperand(0);
- V = EmitBinaryFloatFnCall(V1, V2, Callee->getName(), B,
- Callee->getAttributes());
+ // -> (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;
- if (UnsafeFPShrink && Callee->getName() == "cos" && TLI->has(LibFunc::cosf)) {
+ StringRef Name = Callee->getName();
+ if (UnsafeFPShrink && Name == "cos" && hasFloatVersion(Name))
Ret = optimizeUnaryDoubleFP(CI, B, true);
- }
FunctionType *FT = Callee->getFunctionType();
// Just make sure this has 1 argument of FP type, which matches the
Value *LibCallSimplifier::optimizePow(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
-
Value *Ret = nullptr;
- if (UnsafeFPShrink && Callee->getName() == "pow" && TLI->has(LibFunc::powf)) {
+ StringRef Name = Callee->getName();
+ if (UnsafeFPShrink && Name == "pow" && hasFloatVersion(Name))
Ret = optimizeUnaryDoubleFP(CI, B, true);
- }
FunctionType *FT = Callee->getFunctionType();
// Just make sure this has 2 arguments of the same FP type, which match the
if (Op1C->isExactlyValue(2.0) &&
hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp2, LibFunc::exp2f,
LibFunc::exp2l))
- return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
+ return EmitUnaryFloatFnCall(Op2, TLI->getName(LibFunc::exp2), B,
+ Callee->getAttributes());
// pow(10.0, x) -> exp10(x)
if (Op1C->isExactlyValue(10.0) &&
hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp10, LibFunc::exp10f,
Callee->getAttributes());
}
+ bool unsafeFPMath = canUseUnsafeFPMath(CI->getParent()->getParent());
+
+ // pow(exp(x), y) -> exp(x*y)
+ // pow(exp2(x), y) -> exp2(x * y)
+ // We enable these only under 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).
+ if (unsafeFPMath) {
+ if (auto *OpC = dyn_cast<CallInst>(Op1)) {
+ IRBuilder<>::FastMathFlagGuard Guard(B);
+ FastMathFlags FMF;
+ FMF.setUnsafeAlgebra();
+ B.SetFastMathFlags(FMF);
+
+ LibFunc::Func Func;
+ Function *OpCCallee = OpC->getCalledFunction();
+ if (OpCCallee && TLI->getLibFunc(OpCCallee->getName(), Func) &&
+ TLI->has(Func) && (Func == LibFunc::exp || Func == LibFunc::exp2))
+ return EmitUnaryFloatFnCall(
+ B.CreateFMul(OpC->getArgOperand(0), Op2, "mul"),
+ OpCCallee->getName(), B, OpCCallee->getAttributes());
+ }
+ }
+
ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
if (!Op2C)
return Ret;
LibFunc::sqrtl) &&
hasUnaryFloatFn(TLI, Op2->getType(), LibFunc::fabs, LibFunc::fabsf,
LibFunc::fabsl)) {
+
+ // In -ffast-math, pow(x, 0.5) -> sqrt(x).
+ if (unsafeFPMath)
+ 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 fast-math mode, this could be just sqrt(x).
// 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 *LibCallSimplifier::optimizeExp2(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
Function *Caller = CI->getParent()->getParent();
-
Value *Ret = nullptr;
- if (UnsafeFPShrink && Callee->getName() == "exp2" &&
- TLI->has(LibFunc::exp2f)) {
+ StringRef Name = Callee->getName();
+ if (UnsafeFPShrink && Name == "exp2" && hasFloatVersion(Name))
Ret = optimizeUnaryDoubleFP(CI, B, true);
- }
FunctionType *FT = Callee->getFunctionType();
// Just make sure this has 1 argument of FP type, which matches the
Module *M = Caller->getParent();
Value *Callee =
M->getOrInsertFunction(TLI->getName(LdExp), Op->getType(),
- Op->getType(), B.getInt32Ty(), NULL);
- CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
+ Op->getType(), B.getInt32Ty(), nullptr);
+ CallInst *CI = B.CreateCall(Callee, {One, LdExpArg});
if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
CI->setCallingConv(F->getCallingConv());
Value *LibCallSimplifier::optimizeFabs(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
-
Value *Ret = nullptr;
- if (Callee->getName() == "fabs" && TLI->has(LibFunc::fabsf)) {
+ StringRef Name = Callee->getName();
+ if (Name == "fabs" && hasFloatVersion(Name))
Ret = optimizeUnaryDoubleFP(CI, B, false);
- }
FunctionType *FT = Callee->getFunctionType();
// Make sure this has 1 argument of FP type which matches the result type.
return Ret;
}
-Value *LibCallSimplifier::optimizeSqrt(CallInst *CI, IRBuilder<> &B) {
+Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilder<> &B) {
+ // If we can shrink the call to a float function rather than a double
+ // function, do that first.
Function *Callee = CI->getCalledFunction();
-
- Value *Ret = nullptr;
- if (UnsafeFPShrink && Callee->getName() == "sqrt" &&
- TLI->has(LibFunc::sqrtf)) {
- Ret = optimizeUnaryDoubleFP(CI, B, true);
+ StringRef Name = Callee->getName();
+ if ((Name == "fmin" && hasFloatVersion(Name)) ||
+ (Name == "fmax" && hasFloatVersion(Name))) {
+ Value *Ret = optimizeBinaryDoubleFP(CI, B);
+ if (Ret)
+ return Ret;
}
- // FIXME: For finer-grain optimization, we need intrinsics to have the same
- // fast-math flag decorations that are applied to FP instructions. For now,
- // we have to rely on the function-level unsafe-fp-math attribute to do this
- // optimization because there's no other way to express that the sqrt can be
- // reassociated.
+ // Make sure this has 2 arguments of FP type which match the result type.
+ FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
+ FT->getParamType(0) != FT->getParamType(1) ||
+ !FT->getParamType(0)->isFloatingPointTy())
+ return nullptr;
+
+ IRBuilder<>::FastMathFlagGuard Guard(B);
+ FastMathFlags FMF;
Function *F = CI->getParent()->getParent();
- if (F->hasFnAttribute("unsafe-fp-math")) {
- // Check for unsafe-fp-math = true.
- Attribute Attr = F->getFnAttribute("unsafe-fp-math");
+ if (canUseUnsafeFPMath(F)) {
+ // Unsafe algebra sets all fast-math-flags to true.
+ FMF.setUnsafeAlgebra();
+ } else {
+ // At a minimum, no-nans-fp-math must be true.
+ Attribute Attr = F->getFnAttribute("no-nans-fp-math");
if (Attr.getValueAsString() != "true")
- return Ret;
- }
+ 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);
+ FunctionType *FT = Callee->getFunctionType();
+
+ // Just make sure this has 1 argument of FP type, which matches the
+ // result type.
+ if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
+ !FT->getParamType(0)->isFloatingPointTy())
+ return Ret;
+
+ if (!canUseUnsafeFPMath(CI->getParent()->getParent()))
+ return Ret;
+ Value *Op1 = CI->getArgOperand(0);
+ auto *OpC = dyn_cast<CallInst>(Op1);
+ if (!OpC)
+ 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();
+ StringRef FuncName = F->getName();
+ if ((TLI->getLibFunc(FuncName, 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");
+ 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 (!canUseUnsafeFPMath(CI->getParent()->getParent()))
+ return Ret;
+
Value *Op = CI->getArgOperand(0);
if (Instruction *I = dyn_cast<Instruction>(Op)) {
if (I->getOpcode() == Instruction::FMul && I->hasUnsafeAlgebra()) {
// and multiply.
// FIXME: We're not checking the sqrt because it doesn't have
// fast-math-flags (see earlier comment).
- IRBuilder<true, ConstantFolder,
- IRBuilderDefaultInserter<true> >::FastMathFlagGuard Guard(B);
+ 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.
return Ret;
}
+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);
+ FunctionType *FT = Callee->getFunctionType();
+
+ // Just make sure this has 1 argument of FP type, which matches the
+ // result type.
+ if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
+ !FT->getParamType(0)->isFloatingPointTy())
+ return Ret;
+
+ if (!canUseUnsafeFPMath(CI->getParent()->getParent()))
+ return Ret;
+ Value *Op1 = CI->getArgOperand(0);
+ auto *OpC = dyn_cast<CallInst>(Op1);
+ if (!OpC)
+ 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);
static void insertSinCosCall(IRBuilder<> &B, Function *OrigCallee, Value *Arg,
bool UseFloat, Value *&Sin, Value *&Cos,
return;
Function *Callee = CI->getCalledFunction();
- StringRef FuncName = Callee->getName();
LibFunc::Func Func;
- if (!TLI->getLibFunc(FuncName, Func) || !TLI->has(Func) || !isTrigLibCall(CI))
+ if (!Callee || !TLI->getLibFunc(Callee->getName(), Func) || !TLI->has(Func) ||
+ !isTrigLibCall(CI))
return;
if (IsFloat) {
void LibCallSimplifier::replaceTrigInsts(SmallVectorImpl<CallInst *> &Calls,
Value *Res) {
- for (SmallVectorImpl<CallInst *>::iterator I = Calls.begin(), E = Calls.end();
- I != E; ++I) {
- replaceAllUsesWith(*I, Res);
- }
+ for (CallInst *C : Calls)
+ replaceAllUsesWith(C, Res);
}
void insertSinCosCall(IRBuilder<> &B, Function *OrigCallee, Value *Arg,
// 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, NULL));
+ : static_cast<Type *>(StructType::get(ArgTy, ArgTy, nullptr));
} else {
Name = "__sincospi_stret";
- ResTy = StructType::get(ArgTy, ArgTy, NULL);
+ ResTy = StructType::get(ArgTy, ArgTy, nullptr);
}
Module *M = OrigCallee->getParent();
Value *Callee = M->getOrInsertFunction(Name, OrigCallee->getAttributes(),
- ResTy, ArgTy, NULL);
+ 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.
- BasicBlock::iterator Loc = ArgInst;
- B.SetInsertPoint(ArgInst->getParent(), ++Loc);
+ 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.
// Integer Library Call Optimizations
//===----------------------------------------------------------------------===//
+static bool checkIntUnaryReturnAndParam(Function *Callee) {
+ FunctionType *FT = Callee->getFunctionType();
+ return FT->getNumParams() == 1 && FT->getReturnType()->isIntegerTy(32) &&
+ FT->getParamType(0)->isIntegerTy();
+}
+
Value *LibCallSimplifier::optimizeFFS(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- // Just make sure this has 2 arguments of the same FP type, which match the
- // result type.
- if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy(32) ||
- !FT->getParamType(0)->isIntegerTy())
+ if (!checkIntUnaryReturnAndParam(Callee))
return nullptr;
-
Value *Op = CI->getArgOperand(0);
// Constant fold.
Type *ArgType = Op->getType();
Value *F =
Intrinsic::getDeclaration(Callee->getParent(), Intrinsic::cttz, ArgType);
- Value *V = B.CreateCall2(F, Op, B.getFalse(), "cttz");
+ 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 *LibCallSimplifier::optimizeIsDigit(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- // We require integer(i32)
- if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
- !FT->getParamType(0)->isIntegerTy(32))
+ if (!checkIntUnaryReturnAndParam(CI->getCalledFunction()))
return nullptr;
// isdigit(c) -> (c-'0') <u 10
}
Value *LibCallSimplifier::optimizeIsAscii(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- // We require integer(i32)
- if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
- !FT->getParamType(0)->isIntegerTy(32))
+ if (!checkIntUnaryReturnAndParam(CI->getCalledFunction()))
return nullptr;
// isascii(c) -> c <u 128
}
Value *LibCallSimplifier::optimizeToAscii(CallInst *CI, IRBuilder<> &B) {
- Function *Callee = CI->getCalledFunction();
- FunctionType *FT = Callee->getFunctionType();
- // We require i32(i32)
- if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
- !FT->getParamType(0)->isIntegerTy(32))
+ if (!checkIntUnaryReturnAndParam(CI->getCalledFunction()))
return nullptr;
// toascii(c) -> c & 0x7f
}
static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg) {
- if (!ColdErrorCalls)
- return false;
-
- if (!Callee || !Callee->isDeclaration())
+ if (!ColdErrorCalls || !Callee || !Callee->isDeclaration())
return false;
if (StreamArg < 0)
// printf("x") -> putchar('x'), even for '%'.
if (FormatStr.size() == 1) {
- Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, DL, TLI);
+ Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, TLI);
if (CI->use_empty() || !Res)
return Res;
return B.CreateIntCast(Res, CI->getType(), true);
// pass to be run after this pass, to merge duplicate strings.
FormatStr = FormatStr.drop_back();
Value *GV = B.CreateGlobalString(FormatStr, "str");
- Value *NewCI = EmitPutS(GV, B, DL, TLI);
+ Value *NewCI = EmitPutS(GV, B, TLI);
return (CI->use_empty() || !NewCI)
? NewCI
: ConstantInt::get(CI->getType(), FormatStr.size() + 1);
// printf("%c", chr) --> putchar(chr)
if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
CI->getArgOperand(1)->getType()->isIntegerTy()) {
- Value *Res = EmitPutChar(CI->getArgOperand(1), B, DL, TLI);
+ Value *Res = EmitPutChar(CI->getArgOperand(1), B, TLI);
if (CI->use_empty() || !Res)
return Res;
// printf("%s\n", str) --> puts(str)
if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
CI->getArgOperand(1)->getType()->isPointerTy()) {
- return EmitPutS(CI->getArgOperand(1), B, DL, TLI);
+ return EmitPutS(CI->getArgOperand(1), B, TLI);
}
return nullptr;
}
if (FormatStr[i] == '%')
return nullptr; // we found a format specifier, bail out.
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
// 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.
+ 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());
}
Value *V = B.CreateTrunc(CI->getArgOperand(2), B.getInt8Ty(), "char");
Value *Ptr = CastToCStr(CI->getArgOperand(0), B);
B.CreateStore(V, Ptr);
- Ptr = B.CreateGEP(Ptr, B.getInt32(1), "nul");
+ 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') {
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
// sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
if (!CI->getArgOperand(2)->getType()->isPointerTy())
return nullptr;
if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
return nullptr; // We found a format specifier.
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
return EmitFWrite(
CI->getArgOperand(1),
- ConstantInt::get(DL->getIntPtrType(CI->getContext()), FormatStr.size()),
+ ConstantInt::get(DL.getIntPtrType(CI->getContext()), FormatStr.size()),
CI->getArgOperand(0), B, DL, TLI);
}
// fprintf(F, "%c", chr) --> fputc(chr, F)
if (!CI->getArgOperand(2)->getType()->isIntegerTy())
return nullptr;
- return EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, DL, TLI);
+ 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, DL, TLI);
+ return EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TLI);
}
return nullptr;
}
// 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, DL, TLI);
+ Value *NewCI = EmitFPutC(Char, CI->getArgOperand(3), B, TLI);
return NewCI ? ConstantInt::get(CI->getType(), 1) : nullptr;
}
Function *Callee = CI->getCalledFunction();
- // These optimizations require DataLayout.
- if (!DL)
- return nullptr;
-
// Require two pointers. Also, we can't optimize if return value is used.
FunctionType *FT = Callee->getFunctionType();
if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
// Known to have no uses (see above).
return EmitFWrite(
CI->getArgOperand(0),
- ConstantInt::get(DL->getIntPtrType(CI->getContext()), Len - 1),
+ ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len - 1),
CI->getArgOperand(1), B, DL, TLI);
}
if (Str.empty() && CI->use_empty()) {
// puts("") -> putchar('\n')
- Value *Res = EmitPutChar(B.getInt32('\n'), B, DL, TLI);
+ Value *Res = EmitPutChar(B.getInt32('\n'), B, TLI);
if (CI->use_empty() || !Res)
return Res;
return B.CreateIntCast(Res, CI->getType(), true);
return false;
}
-Value *LibCallSimplifier::optimizeCall(CallInst *CI) {
- if (CI->isNoBuiltin())
- return nullptr;
-
+Value *LibCallSimplifier::optimizeStringMemoryLibCall(CallInst *CI,
+ IRBuilder<> &Builder) {
LibFunc::Func Func;
Function *Callee = CI->getCalledFunction();
StringRef FuncName = Callee->getName();
- IRBuilder<> Builder(CI);
- bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
-
- // Next 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::sqrt:
- return optimizeSqrt(CI, Builder);
- default:
- return nullptr;
- }
- }
- // Then check for known library functions.
+ // Check for string/memory library functions.
if (TLI->getLibFunc(FuncName, Func) && TLI->has(Func)) {
- // We never change the calling convention.
- if (!ignoreCallingConv(Func) && !isCallingConvC)
- return nullptr;
+ // 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);
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 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();
+ IRBuilder<> Builder(CI);
+ bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
+
+ // Command-line parameter overrides function attribute.
+ if (EnableUnsafeFPShrink.getNumOccurrences() > 0)
+ UnsafeFPShrink = EnableUnsafeFPShrink;
+ else if (canUseUnsafeFPMath(Callee))
+ 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);
+ 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(FuncName, 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 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::exp:
case LibFunc::exp10:
case LibFunc::expm1:
- case LibFunc::log:
- case LibFunc::log10:
- case LibFunc::log1p:
- case LibFunc::log2:
- case LibFunc::logb:
case LibFunc::sin:
case LibFunc::sinh:
- case LibFunc::tan:
case LibFunc::tanh:
if (UnsafeFPShrink && hasFloatVersion(FuncName))
return optimizeUnaryDoubleFP(CI, Builder, true);
return nullptr;
- case LibFunc::fmin:
- case LibFunc::fmax:
+ case LibFunc::copysign:
if (hasFloatVersion(FuncName))
return optimizeBinaryDoubleFP(CI, Builder);
return nullptr;
- case LibFunc::memcpy_chk:
- return optimizeMemCpyChk(CI, Builder);
+ 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;
}
}
-
- if (!isCallingConvC)
- return nullptr;
-
- // Finally check for fortified library calls.
- if (FuncName.endswith("_chk")) {
- if (FuncName == "__memmove_chk")
- return optimizeMemMoveChk(CI, Builder);
- else if (FuncName == "__memset_chk")
- return optimizeMemSetChk(CI, Builder);
- else if (FuncName == "__strcpy_chk")
- return optimizeStrCpyChk(CI, Builder);
- else if (FuncName == "__stpcpy_chk")
- return optimizeStpCpyChk(CI, Builder);
- else if (FuncName == "__strncpy_chk")
- return optimizeStrNCpyChk(CI, Builder);
- else if (FuncName == "__stpncpy_chk")
- return optimizeStrNCpyChk(CI, Builder);
- }
-
return nullptr;
}
-LibCallSimplifier::LibCallSimplifier(const DataLayout *DL,
- const TargetLibraryInfo *TLI,
- bool UnsafeFPShrink) :
- DL(DL),
- TLI(TLI),
- UnsafeFPShrink(UnsafeFPShrink) {
-}
+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) const {
- I->replaceAllUsesWith(With);
- I->eraseFromParent();
+void LibCallSimplifier::replaceAllUsesWith(Instruction *I, Value *With) {
+ // Indirect through the replacer used in this instance.
+ Replacer(I, With);
}
// TODO:
// cbrt:
// * cbrt(expN(X)) -> expN(x/3)
// * cbrt(sqrt(x)) -> pow(x,1/6)
-// * cbrt(sqrt(x)) -> pow(x,1/9)
+// * cbrt(cbrt(x)) -> pow(x,1/9)
//
// exp, expf, expl:
// * exp(log(x)) -> x
//
// log, logf, logl:
// * log(exp(x)) -> x
-// * log(x**y) -> y*log(x)
// * log(exp(y)) -> y*log(e)
// * log(exp2(y)) -> y*log(2)
// * log(exp10(y)) -> y*log(10)
// * log(sqrt(x)) -> 0.5*log(x)
-// * log(pow(x,y)) -> y*log(x)
//
// lround, lroundf, lroundl:
// * lround(cnst) -> cnst'
//
// pow, powf, powl:
-// * pow(exp(x),y) -> exp(x*y)
// * pow(sqrt(x),y) -> pow(x,y*0.5)
// * pow(pow(x,y),z)-> pow(x,y*z)
//
// * sqrt(Nroot(x)) -> pow(x,1/(2*N))
// * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
//
-// tan, tanf, tanl:
-// * tan(atan(x)) -> x
-//
// 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) {
+ Function *Callee = CI->getCalledFunction();
+
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memcpy_chk))
+ return nullptr;
+
+ 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) {
+ Function *Callee = CI->getCalledFunction();
+
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memmove_chk))
+ return nullptr;
+
+ 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) {
+ Function *Callee = CI->getCalledFunction();
+
+ if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memset_chk))
+ return nullptr;
+
+ 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();
+
+ if (!checkStringCopyLibFuncSignature(Callee, Func))
+ return nullptr;
+
+ 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 (!checkStringCopyLibFuncSignature(Callee, Func))
+ return nullptr;
+ 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();
+ StringRef FuncName = Callee->getName();
+ IRBuilder<> Builder(CI);
+ bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
+
+ // First, check that this is a known library functions.
+ if (!TLI->getLibFunc(FuncName, 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) {}
projects / oota-llvm.git / blobdiff