//
// This file defines routines for folding instructions into constants.
//
-// Also, to supplement the basic VMCore ConstantExpr simplifications,
+// Also, to supplement the basic IR ConstantExpr simplifications,
// this file defines some additional folding routines that can make use of
-// TargetData information. These functions cannot go in VMCore due to library
+// DataLayout information. These functions cannot go in IR due to library
// dependency issues.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/GlobalVariable.h"
-#include "llvm/Instructions.h"
-#include "llvm/Intrinsics.h"
-#include "llvm/Operator.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetLibraryInfo.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Config/config.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Operator.h"
#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/FEnv.h"
+#include "llvm/Target/TargetLibraryInfo.h"
#include <cerrno>
#include <cmath>
+
+#ifdef HAVE_FENV_H
+#include <fenv.h>
+#endif
+
using namespace llvm;
//===----------------------------------------------------------------------===//
// Constant Folding internal helper functions
//===----------------------------------------------------------------------===//
-/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with
-/// TargetData. This always returns a non-null constant, but it may be a
+/// Constant fold bitcast, symbolically evaluating it with DataLayout.
+/// This always returns a non-null constant, but it may be a
/// ConstantExpr if unfoldable.
static Constant *FoldBitCast(Constant *C, Type *DestTy,
- const TargetData &TD) {
+ const DataLayout &TD) {
// Catch the obvious splat cases.
if (C->isNullValue() && !DestTy->isX86_MMXTy())
return Constant::getNullValue(DestTy);
- if (C->isAllOnesValue() && !DestTy->isX86_MMXTy())
+ if (C->isAllOnesValue() && !DestTy->isX86_MMXTy() &&
+ !DestTy->isPtrOrPtrVectorTy()) // Don't get ones for ptr types!
return Constant::getAllOnesValue(DestTy);
// Handle a vector->integer cast.
if (IntegerType *IT = dyn_cast<IntegerType>(DestTy)) {
- ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(C);
- if (CDV == 0)
+ VectorType *VTy = dyn_cast<VectorType>(C->getType());
+ if (!VTy)
return ConstantExpr::getBitCast(C, DestTy);
- unsigned NumSrcElts = CDV->getType()->getNumElements();
-
- Type *SrcEltTy = CDV->getType()->getElementType();
-
+ unsigned NumSrcElts = VTy->getNumElements();
+ Type *SrcEltTy = VTy->getElementType();
+
// If the vector is a vector of floating point, convert it to vector of int
// to simplify things.
if (SrcEltTy->isFloatingPointTy()) {
unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
Type *SrcIVTy =
VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElts);
- // Ask VMCore to do the conversion now that #elts line up.
+ // Ask IR to do the conversion now that #elts line up.
C = ConstantExpr::getBitCast(C, SrcIVTy);
- CDV = cast<ConstantDataVector>(C);
}
-
+
+ ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(C);
+ if (!CDV)
+ return ConstantExpr::getBitCast(C, DestTy);
+
// Now that we know that the input value is a vector of integers, just shift
// and insert them into our result.
unsigned BitShift = TD.getTypeAllocSizeInBits(SrcEltTy);
else
Result |= CDV->getElementAsInteger(i);
}
-
+
return ConstantInt::get(IT, Result);
}
-
+
// The code below only handles casts to vectors currently.
VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
- if (DestVTy == 0)
+ if (!DestVTy)
return ConstantExpr::getBitCast(C, DestTy);
-
+
// If this is a scalar -> vector cast, convert the input into a <1 x scalar>
// vector so the code below can handle it uniformly.
if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) {
Constant *Ops = C; // don't take the address of C!
return FoldBitCast(ConstantVector::get(Ops), DestTy, TD);
}
-
+
// If this is a bitcast from constant vector -> vector, fold it.
if (!isa<ConstantDataVector>(C) && !isa<ConstantVector>(C))
return ConstantExpr::getBitCast(C, DestTy);
-
- // If the element types match, VMCore can fold it.
+
+ // If the element types match, IR can fold it.
unsigned NumDstElt = DestVTy->getNumElements();
unsigned NumSrcElt = C->getType()->getVectorNumElements();
if (NumDstElt == NumSrcElt)
return ConstantExpr::getBitCast(C, DestTy);
-
+
Type *SrcEltTy = C->getType()->getVectorElementType();
Type *DstEltTy = DestVTy->getElementType();
-
- // Otherwise, we're changing the number of elements in a vector, which
+
+ // Otherwise, we're changing the number of elements in a vector, which
// requires endianness information to do the right thing. For example,
// bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
// folds to (little endian):
// <4 x i32> <i32 0, i32 0, i32 1, i32 0>
// and to (big endian):
// <4 x i32> <i32 0, i32 0, i32 0, i32 1>
-
+
// First thing is first. We only want to think about integer here, so if
// we have something in FP form, recast it as integer.
if (DstEltTy->isFloatingPointTy()) {
VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt);
// Recursively handle this integer conversion, if possible.
C = FoldBitCast(C, DestIVTy, TD);
-
- // Finally, VMCore can handle this now that #elts line up.
+
+ // Finally, IR can handle this now that #elts line up.
return ConstantExpr::getBitCast(C, DestTy);
}
-
+
// Okay, we know the destination is integer, if the input is FP, convert
// it to integer first.
if (SrcEltTy->isFloatingPointTy()) {
unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
Type *SrcIVTy =
VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt);
- // Ask VMCore to do the conversion now that #elts line up.
+ // Ask IR to do the conversion now that #elts line up.
C = ConstantExpr::getBitCast(C, SrcIVTy);
- // If VMCore wasn't able to fold it, bail out.
+ // If IR wasn't able to fold it, bail out.
if (!isa<ConstantVector>(C) && // FIXME: Remove ConstantVector.
!isa<ConstantDataVector>(C))
return C;
}
-
+
// Now we know that the input and output vectors are both integer vectors
// of the same size, and that their #elements is not the same. Do the
// conversion here, which depends on whether the input or output has
// more elements.
bool isLittleEndian = TD.isLittleEndian();
-
+
SmallVector<Constant*, 32> Result;
if (NumDstElt < NumSrcElt) {
// Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
Constant *Src =dyn_cast<ConstantInt>(C->getAggregateElement(SrcElt++));
if (!Src) // Reject constantexpr elements.
return ConstantExpr::getBitCast(C, DestTy);
-
+
// Zero extend the element to the right size.
Src = ConstantExpr::getZExt(Src, Elt->getType());
-
+
// Shift it to the right place, depending on endianness.
- Src = ConstantExpr::getShl(Src,
+ Src = ConstantExpr::getShl(Src,
ConstantInt::get(Src->getType(), ShiftAmt));
ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
-
+
// Mix it in.
Elt = ConstantExpr::getOr(Elt, Src);
}
}
return ConstantVector::get(Result);
}
-
+
// Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
unsigned Ratio = NumDstElt/NumSrcElt;
- unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits();
-
+ unsigned DstBitSize = TD.getTypeSizeInBits(DstEltTy);
+
// Loop over each source value, expanding into multiple results.
for (unsigned i = 0; i != NumSrcElt; ++i) {
Constant *Src = dyn_cast<ConstantInt>(C->getAggregateElement(i));
if (!Src) // Reject constantexpr elements.
return ConstantExpr::getBitCast(C, DestTy);
-
+
unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
for (unsigned j = 0; j != Ratio; ++j) {
// Shift the piece of the value into the right place, depending on
// endianness.
- Constant *Elt = ConstantExpr::getLShr(Src,
+ Constant *Elt = ConstantExpr::getLShr(Src,
ConstantInt::get(Src->getType(), ShiftAmt));
ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
-
+
+ // Truncate the element to an integer with the same pointer size and
+ // convert the element back to a pointer using a inttoptr.
+ if (DstEltTy->isPointerTy()) {
+ IntegerType *DstIntTy = Type::getIntNTy(C->getContext(), DstBitSize);
+ Constant *CE = ConstantExpr::getTrunc(Elt, DstIntTy);
+ Result.push_back(ConstantExpr::getIntToPtr(CE, DstEltTy));
+ continue;
+ }
+
// Truncate and remember this piece.
Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
}
}
-
+
return ConstantVector::get(Result);
}
-/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset
-/// from a global, return the global and the constant. Because of
-/// constantexprs, this function is recursive.
+/// If this constant is a constant offset from a global, return the global and
+/// the constant. Because of constantexprs, this function is recursive.
static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
- int64_t &Offset, const TargetData &TD) {
+ APInt &Offset, const DataLayout &TD) {
// Trivial case, constant is the global.
if ((GV = dyn_cast<GlobalValue>(C))) {
- Offset = 0;
+ unsigned BitWidth = TD.getPointerTypeSizeInBits(GV->getType());
+ Offset = APInt(BitWidth, 0);
return true;
}
-
+
// Otherwise, if this isn't a constant expr, bail out.
ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
if (!CE) return false;
-
+
// Look through ptr->int and ptr->ptr casts.
if (CE->getOpcode() == Instruction::PtrToInt ||
- CE->getOpcode() == Instruction::BitCast)
+ CE->getOpcode() == Instruction::BitCast ||
+ CE->getOpcode() == Instruction::AddrSpaceCast)
return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
-
- // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
- if (CE->getOpcode() == Instruction::GetElementPtr) {
- // Cannot compute this if the element type of the pointer is missing size
- // info.
- if (!cast<PointerType>(CE->getOperand(0)->getType())
- ->getElementType()->isSized())
- return false;
-
- // If the base isn't a global+constant, we aren't either.
- if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD))
- return false;
-
- // Otherwise, add any offset that our operands provide.
- gep_type_iterator GTI = gep_type_begin(CE);
- for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end();
- i != e; ++i, ++GTI) {
- ConstantInt *CI = dyn_cast<ConstantInt>(*i);
- if (!CI) return false; // Index isn't a simple constant?
- if (CI->isZero()) continue; // Not adding anything.
-
- if (StructType *ST = dyn_cast<StructType>(*GTI)) {
- // N = N + Offset
- Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue());
- } else {
- SequentialType *SQT = cast<SequentialType>(*GTI);
- Offset += TD.getTypeAllocSize(SQT->getElementType())*CI->getSExtValue();
- }
- }
- return true;
- }
-
- return false;
+
+ // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
+ GEPOperator *GEP = dyn_cast<GEPOperator>(CE);
+ if (!GEP)
+ return false;
+
+ unsigned BitWidth = TD.getPointerTypeSizeInBits(GEP->getType());
+ APInt TmpOffset(BitWidth, 0);
+
+ // If the base isn't a global+constant, we aren't either.
+ if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, TmpOffset, TD))
+ return false;
+
+ // Otherwise, add any offset that our operands provide.
+ if (!GEP->accumulateConstantOffset(TD, TmpOffset))
+ return false;
+
+ Offset = TmpOffset;
+ return true;
}
-/// ReadDataFromGlobal - Recursive helper to read bits out of global. C is the
-/// constant being copied out of. ByteOffset is an offset into C. CurPtr is the
-/// pointer to copy results into and BytesLeft is the number of bytes left in
-/// the CurPtr buffer. TD is the target data.
+/// Recursive helper to read bits out of global. C is the constant being copied
+/// out of. ByteOffset is an offset into C. CurPtr is the pointer to copy
+/// results into and BytesLeft is the number of bytes left in
+/// the CurPtr buffer. TD is the target data.
static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset,
unsigned char *CurPtr, unsigned BytesLeft,
- const TargetData &TD) {
+ const DataLayout &TD) {
assert(ByteOffset <= TD.getTypeAllocSize(C->getType()) &&
"Out of range access");
-
+
// If this element is zero or undefined, we can just return since *CurPtr is
// zero initialized.
if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
return true;
-
+
if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
if (CI->getBitWidth() > 64 ||
(CI->getBitWidth() & 7) != 0)
return false;
-
+
uint64_t Val = CI->getZExtValue();
unsigned IntBytes = unsigned(CI->getBitWidth()/8);
-
+
for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
- CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8));
+ int n = ByteOffset;
+ if (!TD.isLittleEndian())
+ n = IntBytes - n - 1;
+ CurPtr[i] = (unsigned char)(Val >> (n * 8));
++ByteOffset;
}
return true;
}
-
+
if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
if (CFP->getType()->isDoubleTy()) {
C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), TD);
C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), TD);
return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
}
+ if (CFP->getType()->isHalfTy()){
+ C = FoldBitCast(C, Type::getInt16Ty(C->getContext()), TD);
+ return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
+ }
return false;
}
-
+
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
const StructLayout *SL = TD.getStructLayout(CS->getType());
unsigned Index = SL->getElementContainingOffset(ByteOffset);
uint64_t CurEltOffset = SL->getElementOffset(Index);
ByteOffset -= CurEltOffset;
-
+
while (1) {
// If the element access is to the element itself and not to tail padding,
// read the bytes from the element.
!ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr,
BytesLeft, TD))
return false;
-
+
++Index;
-
+
// Check to see if we read from the last struct element, if so we're done.
if (Index == CS->getType()->getNumElements())
return true;
// If we read all of the bytes we needed from this element we're done.
uint64_t NextEltOffset = SL->getElementOffset(Index);
- if (BytesLeft <= NextEltOffset-CurEltOffset-ByteOffset)
+ if (BytesLeft <= NextEltOffset - CurEltOffset - ByteOffset)
return true;
// Move to the next element of the struct.
- CurPtr += NextEltOffset-CurEltOffset-ByteOffset;
- BytesLeft -= NextEltOffset-CurEltOffset-ByteOffset;
+ CurPtr += NextEltOffset - CurEltOffset - ByteOffset;
+ BytesLeft -= NextEltOffset - CurEltOffset - ByteOffset;
ByteOffset = 0;
CurEltOffset = NextEltOffset;
}
if (isa<ConstantArray>(C) || isa<ConstantVector>(C) ||
isa<ConstantDataSequential>(C)) {
- Type *EltTy = cast<SequentialType>(C->getType())->getElementType();
+ Type *EltTy = C->getType()->getSequentialElementType();
uint64_t EltSize = TD.getTypeAllocSize(EltTy);
uint64_t Index = ByteOffset / EltSize;
uint64_t Offset = ByteOffset - Index * EltSize;
if (ArrayType *AT = dyn_cast<ArrayType>(C->getType()))
NumElts = AT->getNumElements();
else
- NumElts = cast<VectorType>(C->getType())->getNumElements();
+ NumElts = C->getType()->getVectorNumElements();
for (; Index != NumElts; ++Index) {
if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr,
}
return true;
}
-
+
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
if (CE->getOpcode() == Instruction::IntToPtr &&
- CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getContext()))
- return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
+ CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getType())) {
+ return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
BytesLeft, TD);
+ }
}
// Otherwise, unknown initializer type.
}
static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
- const TargetData &TD) {
- Type *LoadTy = cast<PointerType>(C->getType())->getElementType();
+ const DataLayout &TD) {
+ PointerType *PTy = cast<PointerType>(C->getType());
+ Type *LoadTy = PTy->getElementType();
IntegerType *IntType = dyn_cast<IntegerType>(LoadTy);
-
+
// If this isn't an integer load we can't fold it directly.
if (!IntType) {
+ unsigned AS = PTy->getAddressSpace();
+
// If this is a float/double load, we can try folding it as an int32/64 load
// and then bitcast the result. This can be useful for union cases. Note
// that address spaces don't matter here since we're not going to result in
// an actual new load.
Type *MapTy;
- if (LoadTy->isFloatTy())
- MapTy = Type::getInt32PtrTy(C->getContext());
+ if (LoadTy->isHalfTy())
+ MapTy = Type::getInt16PtrTy(C->getContext(), AS);
+ else if (LoadTy->isFloatTy())
+ MapTy = Type::getInt32PtrTy(C->getContext(), AS);
else if (LoadTy->isDoubleTy())
- MapTy = Type::getInt64PtrTy(C->getContext());
+ MapTy = Type::getInt64PtrTy(C->getContext(), AS);
else if (LoadTy->isVectorTy()) {
- MapTy = IntegerType::get(C->getContext(),
- TD.getTypeAllocSizeInBits(LoadTy));
- MapTy = PointerType::getUnqual(MapTy);
+ MapTy = PointerType::getIntNPtrTy(C->getContext(),
+ TD.getTypeAllocSizeInBits(LoadTy),
+ AS);
} else
- return 0;
+ return nullptr;
C = FoldBitCast(C, MapTy, TD);
if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, TD))
return FoldBitCast(Res, LoadTy, TD);
- return 0;
+ return nullptr;
}
-
+
unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
- if (BytesLoaded > 32 || BytesLoaded == 0) return 0;
-
+ if (BytesLoaded > 32 || BytesLoaded == 0)
+ return nullptr;
+
GlobalValue *GVal;
- int64_t Offset;
+ APInt Offset;
if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD))
- return 0;
-
+ return nullptr;
+
GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal);
if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
!GV->getInitializer()->getType()->isSized())
- return 0;
+ return nullptr;
// If we're loading off the beginning of the global, some bytes may be valid,
// but we don't try to handle this.
- if (Offset < 0) return 0;
-
+ if (Offset.isNegative())
+ return nullptr;
+
// If we're not accessing anything in this constant, the result is undefined.
- if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType()))
+ if (Offset.getZExtValue() >=
+ TD.getTypeAllocSize(GV->getInitializer()->getType()))
return UndefValue::get(IntType);
-
+
unsigned char RawBytes[32] = {0};
- if (!ReadDataFromGlobal(GV->getInitializer(), Offset, RawBytes,
+ if (!ReadDataFromGlobal(GV->getInitializer(), Offset.getZExtValue(), RawBytes,
BytesLoaded, TD))
- return 0;
-
- APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]);
- for (unsigned i = 1; i != BytesLoaded; ++i) {
- ResultVal <<= 8;
- ResultVal |= RawBytes[BytesLoaded-1-i];
+ return nullptr;
+
+ APInt ResultVal = APInt(IntType->getBitWidth(), 0);
+ if (TD.isLittleEndian()) {
+ ResultVal = RawBytes[BytesLoaded - 1];
+ for (unsigned i = 1; i != BytesLoaded; ++i) {
+ ResultVal <<= 8;
+ ResultVal |= RawBytes[BytesLoaded - 1 - i];
+ }
+ } else {
+ ResultVal = RawBytes[0];
+ for (unsigned i = 1; i != BytesLoaded; ++i) {
+ ResultVal <<= 8;
+ ResultVal |= RawBytes[i];
+ }
}
return ConstantInt::get(IntType->getContext(), ResultVal);
}
-/// ConstantFoldLoadFromConstPtr - Return the value that a load from C would
-/// produce if it is constant and determinable. If this is not determinable,
-/// return null.
+static Constant *ConstantFoldLoadThroughBitcast(ConstantExpr *CE,
+ const DataLayout *DL) {
+ if (!DL)
+ return nullptr;
+ auto *DestPtrTy = dyn_cast<PointerType>(CE->getType());
+ if (!DestPtrTy)
+ return nullptr;
+ Type *DestTy = DestPtrTy->getElementType();
+
+ Constant *C = ConstantFoldLoadFromConstPtr(CE->getOperand(0), DL);
+ if (!C)
+ return nullptr;
+
+ do {
+ Type *SrcTy = C->getType();
+
+ // If the type sizes are the same and a cast is legal, just directly
+ // cast the constant.
+ if (DL->getTypeSizeInBits(DestTy) == DL->getTypeSizeInBits(SrcTy)) {
+ Instruction::CastOps Cast = Instruction::BitCast;
+ // If we are going from a pointer to int or vice versa, we spell the cast
+ // differently.
+ if (SrcTy->isIntegerTy() && DestTy->isPointerTy())
+ Cast = Instruction::IntToPtr;
+ else if (SrcTy->isPointerTy() && DestTy->isIntegerTy())
+ Cast = Instruction::PtrToInt;
+
+ if (CastInst::castIsValid(Cast, C, DestTy))
+ return ConstantExpr::getCast(Cast, C, DestTy);
+ }
+
+ // If this isn't an aggregate type, there is nothing we can do to drill down
+ // and find a bitcastable constant.
+ if (!SrcTy->isAggregateType())
+ return nullptr;
+
+ // We're simulating a load through a pointer that was bitcast to point to
+ // a different type, so we can try to walk down through the initial
+ // elements of an aggregate to see if some part of th e aggregate is
+ // castable to implement the "load" semantic model.
+ C = C->getAggregateElement(0u);
+ } while (C);
+
+ return nullptr;
+}
+
+/// Return the value that a load from C would produce if it is constant and
+/// determinable. If this is not determinable, return null.
Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C,
- const TargetData *TD) {
+ const DataLayout *TD) {
// First, try the easy cases:
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
if (GV->isConstant() && GV->hasDefinitiveInitializer())
// If the loaded value isn't a constant expr, we can't handle it.
ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
- if (!CE) return 0;
-
+ if (!CE)
+ return nullptr;
+
if (CE->getOpcode() == Instruction::GetElementPtr) {
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
- if (GV->isConstant() && GV->hasDefinitiveInitializer())
- if (Constant *V =
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0))) {
+ if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
+ if (Constant *V =
ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
return V;
+ }
+ }
}
-
+
+ if (CE->getOpcode() == Instruction::BitCast)
+ if (Constant *LoadedC = ConstantFoldLoadThroughBitcast(CE, TD))
+ return LoadedC;
+
// Instead of loading constant c string, use corresponding integer value
// directly if string length is small enough.
StringRef Str;
SingleChar = 0;
StrVal = (StrVal << 8) | SingleChar;
}
-
+
Constant *Res = ConstantInt::get(CE->getContext(), StrVal);
if (Ty->isFloatingPointTy())
Res = ConstantExpr::getBitCast(Res, Ty);
return Res;
}
}
-
+
// If this load comes from anywhere in a constant global, and if the global
// is all undef or zero, we know what it loads.
if (GlobalVariable *GV =
return UndefValue::get(ResTy);
}
}
-
- // Try hard to fold loads from bitcasted strange and non-type-safe things. We
- // currently don't do any of this for big endian systems. It can be
- // generalized in the future if someone is interested.
- if (TD && TD->isLittleEndian())
+
+ // Try hard to fold loads from bitcasted strange and non-type-safe things.
+ if (TD)
return FoldReinterpretLoadFromConstPtr(CE, *TD);
- return 0;
+ return nullptr;
}
-static Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){
- if (LI->isVolatile()) return 0;
-
+static Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout *TD){
+ if (LI->isVolatile()) return nullptr;
+
if (Constant *C = dyn_cast<Constant>(LI->getOperand(0)))
return ConstantFoldLoadFromConstPtr(C, TD);
- return 0;
+ return nullptr;
}
-/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
+/// One of Op0/Op1 is a constant expression.
/// Attempt to symbolically evaluate the result of a binary operator merging
-/// these together. If target data info is available, it is provided as TD,
-/// otherwise TD is null.
+/// these together. If target data info is available, it is provided as DL,
+/// otherwise DL is null.
static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
- Constant *Op1, const TargetData *TD){
+ Constant *Op1, const DataLayout *DL){
// SROA
-
+
// Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
// Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
// bits.
-
-
+
+
+ if (Opc == Instruction::And && DL) {
+ unsigned BitWidth = DL->getTypeSizeInBits(Op0->getType()->getScalarType());
+ APInt KnownZero0(BitWidth, 0), KnownOne0(BitWidth, 0);
+ APInt KnownZero1(BitWidth, 0), KnownOne1(BitWidth, 0);
+ computeKnownBits(Op0, KnownZero0, KnownOne0, DL);
+ computeKnownBits(Op1, KnownZero1, KnownOne1, DL);
+ if ((KnownOne1 | KnownZero0).isAllOnesValue()) {
+ // All the bits of Op0 that the 'and' could be masking are already zero.
+ return Op0;
+ }
+ if ((KnownOne0 | KnownZero1).isAllOnesValue()) {
+ // All the bits of Op1 that the 'and' could be masking are already zero.
+ return Op1;
+ }
+
+ APInt KnownZero = KnownZero0 | KnownZero1;
+ APInt KnownOne = KnownOne0 & KnownOne1;
+ if ((KnownZero | KnownOne).isAllOnesValue()) {
+ return ConstantInt::get(Op0->getType(), KnownOne);
+ }
+ }
+
// If the constant expr is something like &A[123] - &A[4].f, fold this into a
// constant. This happens frequently when iterating over a global array.
- if (Opc == Instruction::Sub && TD) {
+ if (Opc == Instruction::Sub && DL) {
GlobalValue *GV1, *GV2;
- int64_t Offs1, Offs2;
-
- if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD))
- if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) &&
+ APInt Offs1, Offs2;
+
+ if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *DL))
+ if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *DL) &&
GV1 == GV2) {
+ unsigned OpSize = DL->getTypeSizeInBits(Op0->getType());
+
// (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
- return ConstantInt::get(Op0->getType(), Offs1-Offs2);
+ // PtrToInt may change the bitwidth so we have convert to the right size
+ // first.
+ return ConstantInt::get(Op0->getType(), Offs1.zextOrTrunc(OpSize) -
+ Offs2.zextOrTrunc(OpSize));
}
}
-
- return 0;
+
+ return nullptr;
}
-/// CastGEPIndices - If array indices are not pointer-sized integers,
-/// explicitly cast them so that they aren't implicitly casted by the
-/// getelementptr.
+/// If array indices are not pointer-sized integers, explicitly cast them so
+/// that they aren't implicitly casted by the getelementptr.
static Constant *CastGEPIndices(ArrayRef<Constant *> Ops,
- Type *ResultTy, const TargetData *TD,
+ Type *ResultTy, const DataLayout *TD,
const TargetLibraryInfo *TLI) {
- if (!TD) return 0;
- Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext());
+ if (!TD)
+ return nullptr;
+
+ Type *IntPtrTy = TD->getIntPtrType(ResultTy);
bool Any = false;
SmallVector<Constant*, 32> NewIdxs;
for (unsigned i = 1, e = Ops.size(); i != e; ++i) {
if ((i == 1 ||
- !isa<StructType>(GetElementPtrInst::getIndexedType(Ops[0]->getType(),
- Ops.slice(1, i-1)))) &&
+ !isa<StructType>(GetElementPtrInst::getIndexedType(
+ Ops[0]->getType(),
+ Ops.slice(1, i - 1)))) &&
Ops[i]->getType() != IntPtrTy) {
Any = true;
NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i],
} else
NewIdxs.push_back(Ops[i]);
}
- if (!Any) return 0;
- Constant *C =
- ConstantExpr::getGetElementPtr(Ops[0], NewIdxs);
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+ if (!Any)
+ return nullptr;
+
+ Constant *C = ConstantExpr::getGetElementPtr(Ops[0], NewIdxs);
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI))
C = Folded;
+ }
+
return C;
}
static Constant* StripPtrCastKeepAS(Constant* Ptr) {
assert(Ptr->getType()->isPointerTy() && "Not a pointer type");
PointerType *OldPtrTy = cast<PointerType>(Ptr->getType());
- Ptr = cast<Constant>(Ptr->stripPointerCasts());
+ Ptr = Ptr->stripPointerCasts();
PointerType *NewPtrTy = cast<PointerType>(Ptr->getType());
// Preserve the address space number of the pointer.
if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) {
NewPtrTy = NewPtrTy->getElementType()->getPointerTo(
OldPtrTy->getAddressSpace());
- Ptr = ConstantExpr::getBitCast(Ptr, NewPtrTy);
+ Ptr = ConstantExpr::getPointerCast(Ptr, NewPtrTy);
}
return Ptr;
}
-/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP
-/// constant expression, do so.
+/// If we can symbolically evaluate the GEP constant expression, do so.
static Constant *SymbolicallyEvaluateGEP(ArrayRef<Constant *> Ops,
- Type *ResultTy, const TargetData *TD,
+ Type *ResultTy, const DataLayout *TD,
const TargetLibraryInfo *TLI) {
Constant *Ptr = Ops[0];
- if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized() ||
+ if (!TD || !Ptr->getType()->getPointerElementType()->isSized() ||
!Ptr->getType()->isPointerTy())
- return 0;
-
- Type *IntPtrTy = TD->getIntPtrType(Ptr->getContext());
+ return nullptr;
+
+ Type *IntPtrTy = TD->getIntPtrType(Ptr->getType());
+ Type *ResultElementTy = ResultTy->getPointerElementType();
// If this is a constant expr gep that is effectively computing an
// "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
for (unsigned i = 1, e = Ops.size(); i != e; ++i)
if (!isa<ConstantInt>(Ops[i])) {
-
+
// If this is "gep i8* Ptr, (sub 0, V)", fold this as:
// "inttoptr (sub (ptrtoint Ptr), V)"
- if (Ops.size() == 2 &&
- cast<PointerType>(ResultTy)->getElementType()->isIntegerTy(8)) {
+ if (Ops.size() == 2 && ResultElementTy->isIntegerTy(8)) {
ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[1]);
- assert((CE == 0 || CE->getType() == IntPtrTy) &&
+ assert((!CE || CE->getType() == IntPtrTy) &&
"CastGEPIndices didn't canonicalize index types!");
if (CE && CE->getOpcode() == Instruction::Sub &&
CE->getOperand(0)->isNullValue()) {
return Res;
}
}
- return 0;
+ return nullptr;
}
unsigned BitWidth = TD->getTypeSizeInBits(IntPtrTy);
APInt Offset =
APInt(BitWidth, TD->getIndexedOffset(Ptr->getType(),
- makeArrayRef((Value **)Ops.data() + 1,
+ makeArrayRef((Value *const*)
+ Ops.data() + 1,
Ops.size() - 1)));
Ptr = StripPtrCastKeepAS(Ptr);
// If this is a GEP of a GEP, fold it all into a single GEP.
while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
- SmallVector<Value *, 4> NestedOps(GEP->op_begin()+1, GEP->op_end());
+ SmallVector<Value *, 4> NestedOps(GEP->op_begin() + 1, GEP->op_end());
// Do not try the incorporate the sub-GEP if some index is not a number.
bool AllConstantInt = true;
// If the base value for this address is a literal integer value, fold the
// getelementptr to the resulting integer value casted to the pointer type.
APInt BasePtr(BitWidth, 0);
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
- if (CE->getOpcode() == Instruction::IntToPtr)
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
+ if (CE->getOpcode() == Instruction::IntToPtr) {
if (ConstantInt *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
BasePtr = Base->getValue().zextOrTrunc(BitWidth);
+ }
+ }
+
if (Ptr->isNullValue() || BasePtr != 0) {
- Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr);
+ Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr);
return ConstantExpr::getIntToPtr(C, ResultTy);
}
// Also, this helps GlobalOpt do SROA on GlobalVariables.
Type *Ty = Ptr->getType();
assert(Ty->isPointerTy() && "Forming regular GEP of non-pointer type");
- SmallVector<Constant*, 32> NewIdxs;
+ SmallVector<Constant *, 32> NewIdxs;
+
do {
if (SequentialType *ATy = dyn_cast<SequentialType>(Ty)) {
if (ATy->isPointerTy()) {
// The only pointer indexing we'll do is on the first index of the GEP.
if (!NewIdxs.empty())
break;
-
+
// Only handle pointers to sized types, not pointers to functions.
if (!ATy->getElementType()->isSized())
- return 0;
+ return nullptr;
}
-
+
// Determine which element of the array the offset points into.
APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType()));
- IntegerType *IntPtrTy = TD->getIntPtrType(Ty->getContext());
if (ElemSize == 0)
// The element size is 0. This may be [0 x Ty]*, so just use a zero
// index for this level and proceed to the next level to see if it can
// We've reached some non-indexable type.
break;
}
- } while (Ty != cast<PointerType>(ResultTy)->getElementType());
+ } while (Ty != ResultElementTy);
// If we haven't used up the entire offset by descending the static
// type, then the offset is pointing into the middle of an indivisible
// member, so we can't simplify it.
if (Offset != 0)
- return 0;
+ return nullptr;
// Create a GEP.
- Constant *C =
- ConstantExpr::getGetElementPtr(Ptr, NewIdxs);
- assert(cast<PointerType>(C->getType())->getElementType() == Ty &&
+ Constant *C = ConstantExpr::getGetElementPtr(Ptr, NewIdxs);
+ assert(C->getType()->getPointerElementType() == Ty &&
"Computed GetElementPtr has unexpected type!");
// If we ended up indexing a member with a type that doesn't match
// the type of what the original indices indexed, add a cast.
- if (Ty != cast<PointerType>(ResultTy)->getElementType())
+ if (Ty != ResultElementTy)
C = FoldBitCast(C, ResultTy, *TD);
return C;
// Constant Folding public APIs
//===----------------------------------------------------------------------===//
-/// ConstantFoldInstruction - Try to constant fold the specified instruction.
+/// Try to constant fold the specified instruction.
/// If successful, the constant result is returned, if not, null is returned.
/// Note that this fails if not all of the operands are constant. Otherwise,
/// this function can only fail when attempting to fold instructions like loads
/// and stores, which have no constant expression form.
Constant *llvm::ConstantFoldInstruction(Instruction *I,
- const TargetData *TD,
+ const DataLayout *TD,
const TargetLibraryInfo *TLI) {
// Handle PHI nodes quickly here...
if (PHINode *PN = dyn_cast<PHINode>(I)) {
- Constant *CommonValue = 0;
+ Constant *CommonValue = nullptr;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
Value *Incoming = PN->getIncomingValue(i);
// If the incoming value is not a constant, then give up.
Constant *C = dyn_cast<Constant>(Incoming);
if (!C)
- return 0;
+ return nullptr;
// Fold the PHI's operands.
if (ConstantExpr *NewC = dyn_cast<ConstantExpr>(C))
C = ConstantFoldConstantExpression(NewC, TD, TLI);
// If the incoming value is a different constant to
// the one we saw previously, then give up.
if (CommonValue && C != CommonValue)
- return 0;
+ return nullptr;
CommonValue = C;
}
for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) {
Constant *Op = dyn_cast<Constant>(*i);
if (!Op)
- return 0; // All operands not constant!
+ return nullptr; // All operands not constant!
// Fold the Instruction's operands.
if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(Op))
if (const CmpInst *CI = dyn_cast<CmpInst>(I))
return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
TD, TLI);
-
+
if (const LoadInst *LI = dyn_cast<LoadInst>(I))
return ConstantFoldLoadInst(LI, TD);
- if (InsertValueInst *IVI = dyn_cast<InsertValueInst>(I))
+ if (InsertValueInst *IVI = dyn_cast<InsertValueInst>(I)) {
return ConstantExpr::getInsertValue(
cast<Constant>(IVI->getAggregateOperand()),
cast<Constant>(IVI->getInsertedValueOperand()),
IVI->getIndices());
+ }
- if (ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I))
+ if (ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I)) {
return ConstantExpr::getExtractValue(
cast<Constant>(EVI->getAggregateOperand()),
EVI->getIndices());
+ }
return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Ops, TD, TLI);
}
-/// ConstantFoldConstantExpression - Attempt to fold the constant expression
-/// using the specified TargetData. If successful, the constant result is
-/// result is returned, if not, null is returned.
-Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
- const TargetData *TD,
- const TargetLibraryInfo *TLI) {
- SmallVector<Constant*, 8> Ops;
- for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end();
- i != e; ++i) {
+static Constant *
+ConstantFoldConstantExpressionImpl(const ConstantExpr *CE, const DataLayout *TD,
+ const TargetLibraryInfo *TLI,
+ SmallPtrSetImpl<ConstantExpr *> &FoldedOps) {
+ SmallVector<Constant *, 8> Ops;
+ for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); i != e;
+ ++i) {
Constant *NewC = cast<Constant>(*i);
- // Recursively fold the ConstantExpr's operands.
- if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC))
- NewC = ConstantFoldConstantExpression(NewCE, TD, TLI);
+ // Recursively fold the ConstantExpr's operands. If we have already folded
+ // a ConstantExpr, we don't have to process it again.
+ if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC)) {
+ if (FoldedOps.insert(NewCE))
+ NewC = ConstantFoldConstantExpressionImpl(NewCE, TD, TLI, FoldedOps);
+ }
Ops.push_back(NewC);
}
return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), Ops, TD, TLI);
}
-/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
+/// Attempt to fold the constant expression
+/// using the specified DataLayout. If successful, the constant result is
+/// result is returned, if not, null is returned.
+Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
+ const DataLayout *TD,
+ const TargetLibraryInfo *TLI) {
+ SmallPtrSet<ConstantExpr *, 4> FoldedOps;
+ return ConstantFoldConstantExpressionImpl(CE, TD, TLI, FoldedOps);
+}
+
+/// Attempt to constant fold an instruction with the
/// specified opcode and operands. If successful, the constant result is
/// returned, if not, null is returned. Note that this function can fail when
/// attempting to fold instructions like loads and stores, which have no
/// information, due to only being passed an opcode and operands. Constant
/// folding using this function strips this information.
///
-Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
+Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
ArrayRef<Constant *> Ops,
- const TargetData *TD,
- const TargetLibraryInfo *TLI) {
+ const DataLayout *TD,
+ const TargetLibraryInfo *TLI) {
// Handle easy binops first.
if (Instruction::isBinaryOp(Opcode)) {
- if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1]))
+ if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1])) {
if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD))
return C;
-
+ }
+
return ConstantExpr::get(Opcode, Ops[0], Ops[1]);
}
-
+
switch (Opcode) {
- default: return 0;
+ default: return nullptr;
case Instruction::ICmp:
case Instruction::FCmp: llvm_unreachable("Invalid for compares");
case Instruction::Call:
if (Function *F = dyn_cast<Function>(Ops.back()))
if (canConstantFoldCallTo(F))
return ConstantFoldCall(F, Ops.slice(0, Ops.size() - 1), TLI);
- return 0;
+ return nullptr;
case Instruction::PtrToInt:
// If the input is a inttoptr, eliminate the pair. This requires knowing
// the width of a pointer, so it can't be done in ConstantExpr::getCast.
if (TD && CE->getOpcode() == Instruction::IntToPtr) {
Constant *Input = CE->getOperand(0);
unsigned InWidth = Input->getType()->getScalarSizeInBits();
- if (TD->getPointerSizeInBits() < InWidth) {
- Constant *Mask =
- ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth,
- TD->getPointerSizeInBits()));
+ unsigned PtrWidth = TD->getPointerTypeSizeInBits(CE->getType());
+ if (PtrWidth < InWidth) {
+ Constant *Mask =
+ ConstantInt::get(CE->getContext(),
+ APInt::getLowBitsSet(InWidth, PtrWidth));
Input = ConstantExpr::getAnd(Input, Mask);
}
// Do a zext or trunc to get to the dest size.
return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
case Instruction::IntToPtr:
// If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
- // the int size is >= the ptr size. This requires knowing the width of a
- // pointer, so it can't be done in ConstantExpr::getCast.
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
- if (TD &&
- TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() &&
- CE->getOpcode() == Instruction::PtrToInt)
- return FoldBitCast(CE->getOperand(0), DestTy, *TD);
+ // the int size is >= the ptr size and the address spaces are the same.
+ // This requires knowing the width of a pointer, so it can't be done in
+ // ConstantExpr::getCast.
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0])) {
+ if (TD && CE->getOpcode() == Instruction::PtrToInt) {
+ Constant *SrcPtr = CE->getOperand(0);
+ unsigned SrcPtrSize = TD->getPointerTypeSizeInBits(SrcPtr->getType());
+ unsigned MidIntSize = CE->getType()->getScalarSizeInBits();
+
+ if (MidIntSize >= SrcPtrSize) {
+ unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace();
+ if (SrcAS == DestTy->getPointerAddressSpace())
+ return FoldBitCast(CE->getOperand(0), DestTy, *TD);
+ }
+ }
+ }
return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
case Instruction::Trunc:
case Instruction::SIToFP:
case Instruction::FPToUI:
case Instruction::FPToSI:
+ case Instruction::AddrSpaceCast:
return ConstantExpr::getCast(Opcode, Ops[0], DestTy);
case Instruction::BitCast:
if (TD)
return C;
if (Constant *C = SymbolicallyEvaluateGEP(Ops, DestTy, TD, TLI))
return C;
-
+
return ConstantExpr::getGetElementPtr(Ops[0], Ops.slice(1));
}
}
-/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare
+/// Attempt to constant fold a compare
/// instruction (icmp/fcmp) with the specified operands. If it fails, it
/// returns a constant expression of the specified operands.
-///
Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
- Constant *Ops0, Constant *Ops1,
- const TargetData *TD,
+ Constant *Ops0, Constant *Ops1,
+ const DataLayout *TD,
const TargetLibraryInfo *TLI) {
// fold: icmp (inttoptr x), null -> icmp x, 0
// fold: icmp (ptrtoint x), 0 -> icmp x, null
// around to know if bit truncation is happening.
if (ConstantExpr *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
if (TD && Ops1->isNullValue()) {
- Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
if (CE0->getOpcode() == Instruction::IntToPtr) {
+ Type *IntPtrTy = TD->getIntPtrType(CE0->getType());
// Convert the integer value to the right size to ensure we get the
// proper extension or truncation.
Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0),
Constant *Null = Constant::getNullValue(C->getType());
return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI);
}
-
+
// Only do this transformation if the int is intptrty in size, otherwise
// there is a truncation or extension that we aren't modeling.
- if (CE0->getOpcode() == Instruction::PtrToInt &&
- CE0->getType() == IntPtrTy) {
- Constant *C = CE0->getOperand(0);
- Constant *Null = Constant::getNullValue(C->getType());
- return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI);
+ if (CE0->getOpcode() == Instruction::PtrToInt) {
+ Type *IntPtrTy = TD->getIntPtrType(CE0->getOperand(0)->getType());
+ if (CE0->getType() == IntPtrTy) {
+ Constant *C = CE0->getOperand(0);
+ Constant *Null = Constant::getNullValue(C->getType());
+ return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI);
+ }
}
}
-
+
if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
if (TD && CE0->getOpcode() == CE1->getOpcode()) {
- Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
-
if (CE0->getOpcode() == Instruction::IntToPtr) {
+ Type *IntPtrTy = TD->getIntPtrType(CE0->getType());
+
// Convert the integer value to the right size to ensure we get the
// proper extension or truncation.
Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0),
// Only do this transformation if the int is intptrty in size, otherwise
// there is a truncation or extension that we aren't modeling.
- if ((CE0->getOpcode() == Instruction::PtrToInt &&
- CE0->getType() == IntPtrTy &&
- CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()))
- return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0),
- CE1->getOperand(0), TD, TLI);
+ if (CE0->getOpcode() == Instruction::PtrToInt) {
+ Type *IntPtrTy = TD->getIntPtrType(CE0->getOperand(0)->getType());
+ if (CE0->getType() == IntPtrTy &&
+ CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()) {
+ return ConstantFoldCompareInstOperands(Predicate,
+ CE0->getOperand(0),
+ CE1->getOperand(0),
+ TD,
+ TLI);
+ }
+ }
}
}
-
+
// icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0)
// icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0)
if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) &&
CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) {
- Constant *LHS =
+ Constant *LHS =
ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1,
TD, TLI);
- Constant *RHS =
+ Constant *RHS =
ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1,
TD, TLI);
- unsigned OpC =
+ unsigned OpC =
Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
Constant *Ops[] = { LHS, RHS };
return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, TD, TLI);
}
}
-
+
return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
}
-/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a
-/// getelementptr constantexpr, return the constant value being addressed by the
-/// constant expression, or null if something is funny and we can't decide.
-Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
+/// Given a constant and a getelementptr constantexpr, return the constant value
+/// being addressed by the constant expression, or null if something is funny
+/// and we can't decide.
+Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
ConstantExpr *CE) {
if (!CE->getOperand(1)->isNullValue())
- return 0; // Do not allow stepping over the value!
+ return nullptr; // Do not allow stepping over the value!
// Loop over all of the operands, tracking down which value we are
// addressing.
for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i) {
C = C->getAggregateElement(CE->getOperand(i));
- if (C == 0) return 0;
+ if (!C)
+ return nullptr;
}
return C;
}
-/// ConstantFoldLoadThroughGEPIndices - Given a constant and getelementptr
-/// indices (with an *implied* zero pointer index that is not in the list),
-/// return the constant value being addressed by a virtual load, or null if
-/// something is funny and we can't decide.
+/// Given a constant and getelementptr indices (with an *implied* zero pointer
+/// index that is not in the list), return the constant value being addressed by
+/// a virtual load, or null if something is funny and we can't decide.
Constant *llvm::ConstantFoldLoadThroughGEPIndices(Constant *C,
ArrayRef<Constant*> Indices) {
// Loop over all of the operands, tracking down which value we are
// addressing.
for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
C = C->getAggregateElement(Indices[i]);
- if (C == 0) return 0;
+ if (!C)
+ return nullptr;
}
return C;
}
// Constant Folding for Calls
//
-/// canConstantFoldCallTo - Return true if its even possible to fold a call to
-/// the specified function.
-bool
-llvm::canConstantFoldCallTo(const Function *F) {
+/// Return true if it's even possible to fold a call to the specified function.
+bool llvm::canConstantFoldCallTo(const Function *F) {
switch (F->getIntrinsicID()) {
+ case Intrinsic::fabs:
+ case Intrinsic::minnum:
+ case Intrinsic::maxnum:
+ case Intrinsic::log:
+ case Intrinsic::log2:
+ case Intrinsic::log10:
+ case Intrinsic::exp:
+ case Intrinsic::exp2:
+ case Intrinsic::floor:
+ case Intrinsic::ceil:
case Intrinsic::sqrt:
case Intrinsic::pow:
case Intrinsic::powi:
case Intrinsic::ctpop:
case Intrinsic::ctlz:
case Intrinsic::cttz:
+ case Intrinsic::fma:
+ case Intrinsic::fmuladd:
+ case Intrinsic::copysign:
+ case Intrinsic::round:
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::ssub_with_overflow:
case 0: break;
}
- if (!F->hasName()) return false;
+ if (!F->hasName())
+ return false;
StringRef Name = F->getName();
-
+
// In these cases, the check of the length is required. We don't want to
// return true for a name like "cos\0blah" which strcmp would return equal to
// "cos", but has length 8.
switch (Name[0]) {
default: return false;
case 'a':
- return Name == "acos" || Name == "asin" ||
- Name == "atan" || Name == "atan2";
+ return Name == "acos" || Name == "asin" || Name == "atan" || Name =="atan2";
case 'c':
return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh";
case 'e':
}
}
-static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
- Type *Ty) {
- sys::llvm_fenv_clearexcept();
- V = NativeFP(V);
- if (sys::llvm_fenv_testexcept()) {
- sys::llvm_fenv_clearexcept();
- return 0;
+static Constant *GetConstantFoldFPValue(double V, Type *Ty) {
+ if (Ty->isHalfTy()) {
+ APFloat APF(V);
+ bool unused;
+ APF.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &unused);
+ return ConstantFP::get(Ty->getContext(), APF);
}
-
if (Ty->isFloatTy())
return ConstantFP::get(Ty->getContext(), APFloat((float)V));
if (Ty->isDoubleTy())
return ConstantFP::get(Ty->getContext(), APFloat(V));
- llvm_unreachable("Can only constant fold float/double");
+ llvm_unreachable("Can only constant fold half/float/double");
+
+}
+
+namespace {
+/// Clear the floating-point exception state.
+static inline void llvm_fenv_clearexcept() {
+#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT
+ feclearexcept(FE_ALL_EXCEPT);
+#endif
+ errno = 0;
+}
+
+/// Test if a floating-point exception was raised.
+static inline bool llvm_fenv_testexcept() {
+ int errno_val = errno;
+ if (errno_val == ERANGE || errno_val == EDOM)
+ return true;
+#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT && HAVE_DECL_FE_INEXACT
+ if (fetestexcept(FE_ALL_EXCEPT & ~FE_INEXACT))
+ return true;
+#endif
+ return false;
+}
+} // End namespace
+
+static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
+ Type *Ty) {
+ llvm_fenv_clearexcept();
+ V = NativeFP(V);
+ if (llvm_fenv_testexcept()) {
+ llvm_fenv_clearexcept();
+ return nullptr;
+ }
+
+ return GetConstantFoldFPValue(V, Ty);
}
static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
double V, double W, Type *Ty) {
- sys::llvm_fenv_clearexcept();
+ llvm_fenv_clearexcept();
V = NativeFP(V, W);
- if (sys::llvm_fenv_testexcept()) {
- sys::llvm_fenv_clearexcept();
- return 0;
+ if (llvm_fenv_testexcept()) {
+ llvm_fenv_clearexcept();
+ return nullptr;
}
-
- if (Ty->isFloatTy())
- return ConstantFP::get(Ty->getContext(), APFloat((float)V));
- if (Ty->isDoubleTy())
- return ConstantFP::get(Ty->getContext(), APFloat(V));
- llvm_unreachable("Can only constant fold float/double");
+
+ return GetConstantFoldFPValue(V, Ty);
}
-/// ConstantFoldConvertToInt - Attempt to an SSE floating point to integer
-/// conversion of a constant floating point. If roundTowardZero is false, the
-/// default IEEE rounding is used (toward nearest, ties to even). This matches
-/// the behavior of the non-truncating SSE instructions in the default rounding
-/// mode. The desired integer type Ty is used to select how many bits are
-/// available for the result. Returns null if the conversion cannot be
-/// performed, otherwise returns the Constant value resulting from the
-/// conversion.
+/// Attempt to fold an SSE floating point to integer conversion of a constant
+/// floating point. If roundTowardZero is false, the default IEEE rounding is
+/// used (toward nearest, ties to even). This matches the behavior of the
+/// non-truncating SSE instructions in the default rounding mode. The desired
+/// integer type Ty is used to select how many bits are available for the
+/// result. Returns null if the conversion cannot be performed, otherwise
+/// returns the Constant value resulting from the conversion.
static Constant *ConstantFoldConvertToInt(const APFloat &Val,
bool roundTowardZero, Type *Ty) {
// All of these conversion intrinsics form an integer of at most 64bits.
- unsigned ResultWidth = cast<IntegerType>(Ty)->getBitWidth();
+ unsigned ResultWidth = Ty->getIntegerBitWidth();
assert(ResultWidth <= 64 &&
"Can only constant fold conversions to 64 and 32 bit ints");
/*isSigned=*/true, mode,
&isExact);
if (status != APFloat::opOK && status != APFloat::opInexact)
- return 0;
+ return nullptr;
return ConstantInt::get(Ty, UIntVal, /*isSigned=*/true);
}
-/// ConstantFoldCall - Attempt to constant fold a call to the specified function
-/// with the specified arguments, returning null if unsuccessful.
-Constant *
-llvm::ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
- const TargetLibraryInfo *TLI) {
- if (!F->hasName()) return 0;
- StringRef Name = F->getName();
+static double getValueAsDouble(ConstantFP *Op) {
+ Type *Ty = Op->getType();
- Type *Ty = F->getReturnType();
+ if (Ty->isFloatTy())
+ return Op->getValueAPF().convertToFloat();
+
+ if (Ty->isDoubleTy())
+ return Op->getValueAPF().convertToDouble();
+
+ bool unused;
+ APFloat APF = Op->getValueAPF();
+ APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
+ return APF.convertToDouble();
+}
+
+static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
+ Type *Ty, ArrayRef<Constant *> Operands,
+ const TargetLibraryInfo *TLI) {
if (Operands.size() == 1) {
if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) {
- if (F->getIntrinsicID() == Intrinsic::convert_to_fp16) {
+ if (IntrinsicID == Intrinsic::convert_to_fp16) {
APFloat Val(Op->getValueAPF());
bool lost = false;
Val.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &lost);
- return ConstantInt::get(F->getContext(), Val.bitcastToAPInt());
+ return ConstantInt::get(Ty->getContext(), Val.bitcastToAPInt());
}
- if (!TLI)
- return 0;
- if (!Ty->isFloatTy() && !Ty->isDoubleTy())
- return 0;
+ if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
+ return nullptr;
+
+ if (IntrinsicID == Intrinsic::round) {
+ APFloat V = Op->getValueAPF();
+ V.roundToIntegral(APFloat::rmNearestTiesToAway);
+ return ConstantFP::get(Ty->getContext(), V);
+ }
/// We only fold functions with finite arguments. Folding NaN and inf is
/// likely to be aborted with an exception anyway, and some host libms
/// have known errors raising exceptions.
if (Op->getValueAPF().isNaN() || Op->getValueAPF().isInfinity())
- return 0;
+ return nullptr;
/// Currently APFloat versions of these functions do not exist, so we use
/// the host native double versions. Float versions are not called
/// directly but for all these it is true (float)(f((double)arg)) ==
/// f(arg). Long double not supported yet.
- double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() :
- Op->getValueAPF().convertToDouble();
+ double V = getValueAsDouble(Op);
+
+ switch (IntrinsicID) {
+ default: break;
+ case Intrinsic::fabs:
+ return ConstantFoldFP(fabs, V, Ty);
+#if HAVE_LOG2
+ case Intrinsic::log2:
+ return ConstantFoldFP(log2, V, Ty);
+#endif
+#if HAVE_LOG
+ case Intrinsic::log:
+ return ConstantFoldFP(log, V, Ty);
+#endif
+#if HAVE_LOG10
+ case Intrinsic::log10:
+ return ConstantFoldFP(log10, V, Ty);
+#endif
+#if HAVE_EXP
+ case Intrinsic::exp:
+ return ConstantFoldFP(exp, V, Ty);
+#endif
+#if HAVE_EXP2
+ case Intrinsic::exp2:
+ return ConstantFoldFP(exp2, V, Ty);
+#endif
+ case Intrinsic::floor:
+ return ConstantFoldFP(floor, V, Ty);
+ case Intrinsic::ceil:
+ return ConstantFoldFP(ceil, V, Ty);
+ }
+
+ if (!TLI)
+ return nullptr;
+
switch (Name[0]) {
case 'a':
if (Name == "acos" && TLI->has(LibFunc::acos))
case 'e':
if (Name == "exp" && TLI->has(LibFunc::exp))
return ConstantFoldFP(exp, V, Ty);
-
+
if (Name == "exp2" && TLI->has(LibFunc::exp2)) {
// Constant fold exp2(x) as pow(2,x) in case the host doesn't have a
// C99 library.
return ConstantFoldFP(log, V, Ty);
else if (Name == "log10" && V > 0 && TLI->has(LibFunc::log10))
return ConstantFoldFP(log10, V, Ty);
- else if (F->getIntrinsicID() == Intrinsic::sqrt &&
- (Ty->isFloatTy() || Ty->isDoubleTy())) {
+ else if (IntrinsicID == Intrinsic::sqrt &&
+ (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy())) {
if (V >= -0.0)
return ConstantFoldFP(sqrt, V, Ty);
- else // Undefined
- return Constant::getNullValue(Ty);
+ else {
+ // Unlike the sqrt definitions in C/C++, POSIX, and IEEE-754 - which
+ // all guarantee or favor returning NaN - the square root of a
+ // negative number is not defined for the LLVM sqrt intrinsic.
+ // This is because the intrinsic should only be emitted in place of
+ // libm's sqrt function when using "no-nans-fp-math".
+ return UndefValue::get(Ty);
+ }
}
break;
case 's':
default:
break;
}
- return 0;
+ return nullptr;
}
if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
case Intrinsic::bswap:
- return ConstantInt::get(F->getContext(), Op->getValue().byteSwap());
+ return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap());
case Intrinsic::ctpop:
return ConstantInt::get(Ty, Op->getValue().countPopulation());
case Intrinsic::convert_from_fp16: {
- APFloat Val(Op->getValue());
+ APFloat Val(APFloat::IEEEhalf, Op->getValue());
bool lost = false;
APFloat::opStatus status =
assert(status == APFloat::opOK && !lost &&
"Precision lost during fp16 constfolding");
- return ConstantFP::get(F->getContext(), Val);
+ return ConstantFP::get(Ty->getContext(), Val);
}
default:
- return 0;
+ return nullptr;
}
}
// Support ConstantVector in case we have an Undef in the top.
- if (isa<ConstantVector>(Operands[0]) ||
+ if (isa<ConstantVector>(Operands[0]) ||
isa<ConstantDataVector>(Operands[0])) {
Constant *Op = cast<Constant>(Operands[0]);
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
default: break;
case Intrinsic::x86_sse_cvtss2si:
case Intrinsic::x86_sse_cvtss2si64:
case Intrinsic::x86_sse2_cvttsd2si64:
if (ConstantFP *FPOp =
dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
- return ConstantFoldConvertToInt(FPOp->getValueAPF(),
+ return ConstantFoldConvertToInt(FPOp->getValueAPF(),
/*roundTowardZero=*/true, Ty);
}
}
-
+
if (isa<UndefValue>(Operands[0])) {
- if (F->getIntrinsicID() == Intrinsic::bswap)
+ if (IntrinsicID == Intrinsic::bswap)
return Operands[0];
- return 0;
+ return nullptr;
}
- return 0;
+ return nullptr;
}
if (Operands.size() == 2) {
if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
- if (!Ty->isFloatTy() && !Ty->isDoubleTy())
- return 0;
- double Op1V = Ty->isFloatTy() ?
- (double)Op1->getValueAPF().convertToFloat() :
- Op1->getValueAPF().convertToDouble();
+ if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
+ return nullptr;
+ double Op1V = getValueAsDouble(Op1);
+
if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
if (Op2->getType() != Op1->getType())
- return 0;
-
- double Op2V = Ty->isFloatTy() ?
- (double)Op2->getValueAPF().convertToFloat():
- Op2->getValueAPF().convertToDouble();
+ return nullptr;
- if (F->getIntrinsicID() == Intrinsic::pow) {
+ double Op2V = getValueAsDouble(Op2);
+ if (IntrinsicID == Intrinsic::pow) {
return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
}
+ if (IntrinsicID == Intrinsic::copysign) {
+ APFloat V1 = Op1->getValueAPF();
+ APFloat V2 = Op2->getValueAPF();
+ V1.copySign(V2);
+ return ConstantFP::get(Ty->getContext(), V1);
+ }
+
+ if (IntrinsicID == Intrinsic::minnum) {
+ const APFloat &C1 = Op1->getValueAPF();
+ const APFloat &C2 = Op2->getValueAPF();
+ return ConstantFP::get(Ty->getContext(), minnum(C1, C2));
+ }
+
+ if (IntrinsicID == Intrinsic::maxnum) {
+ const APFloat &C1 = Op1->getValueAPF();
+ const APFloat &C2 = Op2->getValueAPF();
+ return ConstantFP::get(Ty->getContext(), maxnum(C1, C2));
+ }
+
if (!TLI)
- return 0;
+ return nullptr;
if (Name == "pow" && TLI->has(LibFunc::pow))
return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
if (Name == "fmod" && TLI->has(LibFunc::fmod))
if (Name == "atan2" && TLI->has(LibFunc::atan2))
return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
} else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
- if (F->getIntrinsicID() == Intrinsic::powi && Ty->isFloatTy())
- return ConstantFP::get(F->getContext(),
+ if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy())
+ return ConstantFP::get(Ty->getContext(),
+ APFloat((float)std::pow((float)Op1V,
+ (int)Op2C->getZExtValue())));
+ if (IntrinsicID == Intrinsic::powi && Ty->isFloatTy())
+ return ConstantFP::get(Ty->getContext(),
APFloat((float)std::pow((float)Op1V,
(int)Op2C->getZExtValue())));
- if (F->getIntrinsicID() == Intrinsic::powi && Ty->isDoubleTy())
- return ConstantFP::get(F->getContext(),
+ if (IntrinsicID == Intrinsic::powi && Ty->isDoubleTy())
+ return ConstantFP::get(Ty->getContext(),
APFloat((double)std::pow((double)Op1V,
(int)Op2C->getZExtValue())));
}
- return 0;
+ return nullptr;
}
-
+
if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
default: break;
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::umul_with_overflow: {
APInt Res;
bool Overflow;
- switch (F->getIntrinsicID()) {
+ switch (IntrinsicID) {
default: llvm_unreachable("Invalid case");
case Intrinsic::sadd_with_overflow:
Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow);
break;
}
Constant *Ops[] = {
- ConstantInt::get(F->getContext(), Res),
- ConstantInt::get(Type::getInt1Ty(F->getContext()), Overflow)
+ ConstantInt::get(Ty->getContext(), Res),
+ ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow)
};
- return ConstantStruct::get(cast<StructType>(F->getReturnType()), Ops);
+ return ConstantStruct::get(cast<StructType>(Ty), Ops);
}
case Intrinsic::cttz:
- // FIXME: This should check for Op2 == 1, and become unreachable if
- // Op1 == 0.
+ if (Op2->isOne() && Op1->isZero()) // cttz(0, 1) is undef.
+ return UndefValue::get(Ty);
return ConstantInt::get(Ty, Op1->getValue().countTrailingZeros());
case Intrinsic::ctlz:
- // FIXME: This should check for Op2 == 1, and become unreachable if
- // Op1 == 0.
+ if (Op2->isOne() && Op1->isZero()) // ctlz(0, 1) is undef.
+ return UndefValue::get(Ty);
return ConstantInt::get(Ty, Op1->getValue().countLeadingZeros());
}
}
-
- return 0;
+
+ return nullptr;
+ }
+ return nullptr;
+ }
+
+ if (Operands.size() != 3)
+ return nullptr;
+
+ if (const ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
+ if (const ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
+ if (const ConstantFP *Op3 = dyn_cast<ConstantFP>(Operands[2])) {
+ switch (IntrinsicID) {
+ default: break;
+ case Intrinsic::fma:
+ case Intrinsic::fmuladd: {
+ APFloat V = Op1->getValueAPF();
+ APFloat::opStatus s = V.fusedMultiplyAdd(Op2->getValueAPF(),
+ Op3->getValueAPF(),
+ APFloat::rmNearestTiesToEven);
+ if (s != APFloat::opInvalidOp)
+ return ConstantFP::get(Ty->getContext(), V);
+
+ return nullptr;
+ }
+ }
+ }
}
- return 0;
}
- return 0;
+
+ return nullptr;
+}
+
+static Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
+ VectorType *VTy,
+ ArrayRef<Constant *> Operands,
+ const TargetLibraryInfo *TLI) {
+ SmallVector<Constant *, 4> Result(VTy->getNumElements());
+ SmallVector<Constant *, 4> Lane(Operands.size());
+ Type *Ty = VTy->getElementType();
+
+ for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
+ // Gather a column of constants.
+ for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) {
+ Constant *Agg = Operands[J]->getAggregateElement(I);
+ if (!Agg)
+ return nullptr;
+
+ Lane[J] = Agg;
+ }
+
+ // Use the regular scalar folding to simplify this column.
+ Constant *Folded = ConstantFoldScalarCall(Name, IntrinsicID, Ty, Lane, TLI);
+ if (!Folded)
+ return nullptr;
+ Result[I] = Folded;
+ }
+
+ return ConstantVector::get(Result);
+}
+
+/// Attempt to constant fold a call to the specified function
+/// with the specified arguments, returning null if unsuccessful.
+Constant *
+llvm::ConstantFoldCall(Function *F, ArrayRef<Constant *> Operands,
+ const TargetLibraryInfo *TLI) {
+ if (!F->hasName())
+ return nullptr;
+ StringRef Name = F->getName();
+
+ Type *Ty = F->getReturnType();
+
+ if (VectorType *VTy = dyn_cast<VectorType>(Ty))
+ return ConstantFoldVectorCall(Name, F->getIntrinsicID(), VTy, Operands, TLI);
+
+ return ConstantFoldScalarCall(Name, F->getIntrinsicID(), Ty, Operands, TLI);
}
projects / oota-llvm.git / blobdiff