//
// 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/SmallVector.h"
#include "llvm/ADT/StringMap.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.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/FEnv.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>
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
+/// FoldBitCast - 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())
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)
+ return ConstantExpr::getBitCast(C, DestTy);
+
+ unsigned NumSrcElts = CDV->getType()->getNumElements();
+
+ Type *SrcEltTy = CDV->getType()->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 IR to do the conversion now that #elts line up.
+ C = ConstantExpr::getBitCast(C, SrcIVTy);
+ CDV = cast<ConstantDataVector>(C);
+ }
+
+ // 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);
+ APInt Result(IT->getBitWidth(), 0);
+ for (unsigned i = 0; i != NumSrcElts; ++i) {
+ Result <<= BitShift;
+ if (TD.isLittleEndian())
+ Result |= CDV->getElementAsInteger(NumSrcElts-i-1);
+ 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)
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.
- ConstantVector *CV = dyn_cast<ConstantVector>(C);
- if (CV == 0)
+ 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 = CV->getNumOperands();
+ unsigned NumSrcElt = C->getType()->getVectorNumElements();
if (NumDstElt == NumSrcElt)
return ConstantExpr::getBitCast(C, DestTy);
-
- Type *SrcEltTy = CV->getType()->getElementType();
+
+ 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);
- if (!C) return ConstantExpr::getBitCast(C, DestTy);
-
- // 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);
- CV = dyn_cast<ConstantVector>(C);
- if (!CV) // 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 *Elt = Zero;
unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
for (unsigned j = 0; j != Ratio; ++j) {
- Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(SrcElt++));
+ 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);
}
Result.push_back(Elt);
}
- } else {
- // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
- unsigned Ratio = NumDstElt/NumSrcElt;
- unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits();
-
- // Loop over each source value, expanding into multiple results.
- for (unsigned i = 0; i != NumSrcElt; ++i) {
- Constant *Src = dyn_cast<ConstantInt>(CV->getOperand(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,
- ConstantInt::get(Src->getType(), ShiftAmt));
- ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
-
- // Truncate and remember this piece.
- Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
- }
+ 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();
+
+ // 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,
+ ConstantInt::get(Src->getType(), ShiftAmt));
+ ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
+
+ // Truncate and remember this piece.
+ Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
}
}
-
+
return ConstantVector::get(Result);
}
/// 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) {
+ int64_t &Offset, const DataLayout &TD) {
// Trivial case, constant is the global.
if ((GV = dyn_cast<GlobalValue>(C))) {
Offset = 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)
return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
-
- // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
+
+ // 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();
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());
}
return true;
}
-
+
return false;
}
/// 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);
}
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;
// not reached.
}
- if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
- uint64_t EltSize = TD.getTypeAllocSize(CA->getType()->getElementType());
+ if (isa<ConstantArray>(C) || isa<ConstantVector>(C) ||
+ isa<ConstantDataSequential>(C)) {
+ Type *EltTy = cast<SequentialType>(C->getType())->getElementType();
+ uint64_t EltSize = TD.getTypeAllocSize(EltTy);
uint64_t Index = ByteOffset / EltSize;
uint64_t Offset = ByteOffset - Index * EltSize;
- for (; Index != CA->getType()->getNumElements(); ++Index) {
- if (!ReadDataFromGlobal(CA->getOperand(Index), Offset, CurPtr,
- BytesLeft, TD))
- return false;
- if (EltSize >= BytesLeft)
- return true;
-
- Offset = 0;
- BytesLeft -= EltSize;
- CurPtr += EltSize;
- }
- return true;
- }
-
- if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
- uint64_t EltSize = TD.getTypeAllocSize(CV->getType()->getElementType());
- uint64_t Index = ByteOffset / EltSize;
- uint64_t Offset = ByteOffset - Index * EltSize;
- for (; Index != CV->getType()->getNumElements(); ++Index) {
- if (!ReadDataFromGlobal(CV->getOperand(Index), Offset, CurPtr,
- BytesLeft, TD))
- return false;
- if (EltSize >= BytesLeft)
- return true;
-
- Offset = 0;
- BytesLeft -= EltSize;
- CurPtr += EltSize;
- }
- return true;
- }
-
- if (ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(C)) {
- uint64_t EltSize = CDS->getElementByteSize();
- uint64_t Index = ByteOffset / EltSize;
- uint64_t Offset = ByteOffset - Index * EltSize;
- for (; Index != CDS->getType()->getNumElements(); ++Index) {
- if (!ReadDataFromGlobal(CDS->getElementAsConstant(Index), Offset, CurPtr,
+ uint64_t NumElts;
+ if (ArrayType *AT = dyn_cast<ArrayType>(C->getType()))
+ NumElts = AT->getNumElements();
+ else
+ NumElts = cast<VectorType>(C->getType())->getNumElements();
+
+ for (; Index != NumElts; ++Index) {
+ if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr,
BytesLeft, TD))
return false;
- if (EltSize >= BytesLeft)
+
+ uint64_t BytesWritten = EltSize - Offset;
+ assert(BytesWritten <= EltSize && "Not indexing into this element?");
+ if (BytesWritten >= BytesLeft)
return true;
-
+
Offset = 0;
- BytesLeft -= EltSize;
- CurPtr += EltSize;
+ BytesLeft -= BytesWritten;
+ CurPtr += BytesWritten;
}
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,
- BytesLeft, TD);
+ CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getContext()))
+ return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
+ BytesLeft, TD);
}
// Otherwise, unknown initializer type.
}
static Constant *FoldReinterpretLoadFromConstPtr(Constant *C,
- const TargetData &TD) {
+ const DataLayout &TD) {
Type *LoadTy = cast<PointerType>(C->getType())->getElementType();
IntegerType *IntType = dyn_cast<IntegerType>(LoadTy);
-
+
// If this isn't an integer load we can't fold it directly.
if (!IntType) {
// If this is a float/double load, we can try folding it as an int32/64 load
return FoldBitCast(Res, LoadTy, TD);
return 0;
}
-
+
unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
if (BytesLoaded > 32 || BytesLoaded == 0) return 0;
-
+
GlobalValue *GVal;
int64_t Offset;
if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD))
return 0;
-
+
GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal);
if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
!GV->getInitializer()->getType()->isSized())
// 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 we're not accessing anything in this constant, the result is undefined.
if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType()))
return UndefValue::get(IntType);
-
+
unsigned char RawBytes[32] = {0};
if (!ReadDataFromGlobal(GV->getInitializer(), Offset, 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];
+ 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);
/// 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->getOpcode() == Instruction::GetElementPtr) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
if (GV->isConstant() && GV->hasDefinitiveInitializer())
- if (Constant *V =
+ if (Constant *V =
ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
return V;
}
-
+
// Instead of loading constant c string, use corresponding integer value
// directly if string length is small enough.
- std::string Str;
- if (TD && GetConstantStringInfo(CE, Str) && !Str.empty()) {
- unsigned StrLen = Str.length();
+ StringRef Str;
+ if (TD && getConstantStringInfo(CE, Str) && !Str.empty()) {
+ unsigned StrLen = Str.size();
Type *Ty = cast<PointerType>(CE->getType())->getElementType();
unsigned NumBits = Ty->getPrimitiveSizeInBits();
// Replace load with immediate integer if the result is an integer or fp
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;
}
-static Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){
+static Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout *TD){
if (LI->isVolatile()) return 0;
-
+
if (Constant *C = dyn_cast<Constant>(LI->getOperand(0)))
return ConstantFoldLoadFromConstPtr(C, TD);
/// SymbolicallyEvaluateBinop - 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,
+/// these together. If target data info is available, it is provided as TD,
/// otherwise TD is null.
static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
- Constant *Op1, const TargetData *TD){
+ Constant *Op1, const DataLayout *TD){
// 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 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) {
GlobalValue *GV1, *GV2;
int64_t Offs1, Offs2;
-
+
if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD))
if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) &&
GV1 == GV2) {
return ConstantInt::get(Op0->getType(), Offs1-Offs2);
}
}
-
+
return 0;
}
/// 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());
return C;
}
+/// Strip the pointer casts, but preserve the address space information.
+static Constant* StripPtrCastKeepAS(Constant* Ptr) {
+ assert(Ptr->getType()->isPointerTy() && "Not a pointer type");
+ PointerType *OldPtrTy = cast<PointerType>(Ptr->getType());
+ Ptr = cast<Constant>(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);
+ }
+ return Ptr;
+}
+
/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified 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() ||
!Ptr->getType()->isPointerTy())
return 0;
-
+
Type *IntPtrTy = TD->getIntPtrType(Ptr->getContext());
// 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 &&
}
return 0;
}
-
+
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 = cast<Constant>(Ptr->stripPointerCasts());
+ 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)) {
Ptr = cast<Constant>(GEP->getOperand(0));
Offset += APInt(BitWidth,
TD->getIndexedOffset(Ptr->getType(), NestedOps));
- Ptr = cast<Constant>(Ptr->stripPointerCasts());
+ Ptr = StripPtrCastKeepAS(Ptr);
}
// If the base value for this address is a literal integer value, fold the
// This makes it easy to determine if the getelementptr is "inbounds".
// 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;
do {
if (SequentialType *ATy = dyn_cast<SequentialType>(Ty)) {
// 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;
}
-
+
// Determine which element of the array the offset points into.
APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType()));
IntegerType *IntPtrTy = TD->getIntPtrType(Ty->getContext());
}
Ty = ATy->getElementType();
} else if (StructType *STy = dyn_cast<StructType>(Ty)) {
- // Determine which field of the struct the offset points into. The
- // getZExtValue is at least as safe as the StructLayout API because we
- // know the offset is within the struct at this point.
+ // If we end up with an offset that isn't valid for this struct type, we
+ // can't re-form this GEP in a regular form, so bail out. The pointer
+ // operand likely went through casts that are necessary to make the GEP
+ // sensible.
const StructLayout &SL = *TD->getStructLayout(STy);
+ if (Offset.uge(SL.getSizeInBytes()))
+ break;
+
+ // Determine which field of the struct the offset points into. The
+ // getZExtValue is fine as we've already ensured that the offset is
+ // within the range representable by the StructLayout API.
unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue());
NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Ty->getContext()),
ElIdx));
/// 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)) {
// all operands are constants.
if (isa<UndefValue>(Incoming))
continue;
- // If the incoming value is not a constant, or is a different constant to
- // the one we saw previously, then give up.
+ // If the incoming value is not a constant, then give up.
Constant *C = dyn_cast<Constant>(Incoming);
- if (!C || (CommonValue && C != CommonValue))
+ if (!C)
+ return 0;
+ // 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;
CommonValue = C;
}
+
// If we reach here, all incoming values are the same constant or undef.
return CommonValue ? CommonValue : UndefValue::get(PN->getType());
}
// Scan the operand list, checking to see if they are all constants, if so,
// hand off to ConstantFoldInstOperands.
SmallVector<Constant*, 8> Ops;
- for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i)
- if (Constant *Op = dyn_cast<Constant>(*i))
- Ops.push_back(Op);
- else
+ 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!
+ // Fold the Instruction's operands.
+ if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(Op))
+ Op = ConstantFoldConstantExpression(NewCE, TD, TLI);
+
+ Ops.push_back(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);
}
/// ConstantFoldConstantExpression - Attempt to fold the constant expression
-/// using the specified TargetData. If successful, the constant result is
+/// 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 TargetData *TD,
+ const DataLayout *TD,
const TargetLibraryInfo *TLI) {
SmallVector<Constant*, 8> Ops;
for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end();
/// 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 (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD))
return C;
-
+
return ConstantExpr::get(Opcode, Ops[0], Ops[1]);
}
-
+
switch (Opcode) {
default: return 0;
case Instruction::ICmp:
- case Instruction::FCmp: assert(0 && "Invalid for compares");
+ case Instruction::FCmp: llvm_unreachable("Invalid for compares");
case Instruction::Call:
if (Function *F = dyn_cast<Function>(Ops.back()))
if (canConstantFoldCallTo(F))
Constant *Input = CE->getOperand(0);
unsigned InWidth = Input->getType()->getScalarSizeInBits();
if (TD->getPointerSizeInBits() < InWidth) {
- Constant *Mask =
+ Constant *Mask =
ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth,
TD->getPointerSizeInBits()));
Input = ConstantExpr::getAnd(Input, Mask);
return C;
if (Constant *C = SymbolicallyEvaluateGEP(Ops, DestTy, TD, TLI))
return C;
-
+
return ConstantExpr::getGetElementPtr(Ops[0], Ops.slice(1));
}
}
/// 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
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 &&
+ 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 (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
if (TD && CE0->getOpcode() == CE1->getOpcode()) {
Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
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,
+Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
ConstantExpr *CE) {
if (!CE->getOperand(1)->isNullValue())
return 0; // Do not allow stepping over the value!
-
- SmallVector<Constant*, 8> Indices(CE->getNumOperands()-2);
- for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i)
- Indices[i-2] = CE->getOperand(i);
- return ConstantFoldLoadThroughGEPIndices(C, Indices);
+
+ // 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;
+ }
+ return C;
}
/// ConstantFoldLoadThroughGEPIndices - Given a constant and getelementptr
// Loop over all of the operands, tracking down which value we are
// addressing.
for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
- ConstantInt *Idx = dyn_cast<ConstantInt>(Indices[i]);
- if (Idx == 0) return 0;
-
- uint64_t IdxVal = Idx->getZExtValue();
-
- if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
- C = CS->getOperand(IdxVal);
- } else if (ConstantAggregateZero *CAZ = dyn_cast<ConstantAggregateZero>(C)){
- C = CAZ->getElementValue(Idx);
- } else if (UndefValue *UV = dyn_cast<UndefValue>(C)) {
- C = UV->getElementValue(Idx);
- } else if (ConstantArray *CA = dyn_cast<ConstantArray>(C)) {
- if (IdxVal >= CA->getType()->getNumElements())
- return 0;
- C = CA->getOperand(IdxVal);
- } else if (ConstantDataSequential *CDS=dyn_cast<ConstantDataSequential>(C)){
- if (IdxVal >= CDS->getType()->getNumElements())
- return 0;
- C = CDS->getElementAsConstant(IdxVal);
- } else if (ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
- if (IdxVal >= CV->getType()->getNumElements())
- return 0;
- C = CV->getOperand(IdxVal);
- } else {
- return 0;
- }
+ C = C->getAggregateElement(Indices[i]);
+ if (C == 0) return 0;
}
return C;
}
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" ||
+ return Name == "acos" || Name == "asin" ||
Name == "atan" || Name == "atan2";
case 'c':
return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh";
}
}
-static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
+static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
Type *Ty) {
sys::llvm_fenv_clearexcept();
V = NativeFP(V);
sys::llvm_fenv_clearexcept();
return 0;
}
-
+
if (Ty->isFloatTy())
return ConstantFP::get(Ty->getContext(), APFloat((float)V));
if (Ty->isDoubleTy())
sys::llvm_fenv_clearexcept();
return 0;
}
-
+
if (Ty->isFloatTy())
return ConstantFP::get(Ty->getContext(), APFloat((float)V));
if (Ty->isDoubleTy())
/// available for the result. Returns null if the conversion cannot be
/// performed, otherwise returns the Constant value resulting from the
/// conversion.
-static Constant *ConstantFoldConvertToInt(ConstantFP *Op, bool roundTowardZero,
- Type *Ty) {
- assert(Op && "Called with NULL operand");
- APFloat Val(Op->getValueAPF());
-
+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();
assert(ResultWidth <= 64 &&
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.
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 =
}
}
- if (ConstantVector *Op = dyn_cast<ConstantVector>(Operands[0])) {
+ // Support ConstantVector in case we have an Undef in the top.
+ if (isa<ConstantVector>(Operands[0]) ||
+ isa<ConstantDataVector>(Operands[0])) {
+ Constant *Op = cast<Constant>(Operands[0]);
switch (F->getIntrinsicID()) {
default: break;
case Intrinsic::x86_sse_cvtss2si:
case Intrinsic::x86_sse_cvtss2si64:
case Intrinsic::x86_sse2_cvtsd2si:
case Intrinsic::x86_sse2_cvtsd2si64:
- if (ConstantFP *FPOp = dyn_cast<ConstantFP>(Op->getOperand(0)))
- return ConstantFoldConvertToInt(FPOp, /*roundTowardZero=*/false, Ty);
+ if (ConstantFP *FPOp =
+ dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
+ return ConstantFoldConvertToInt(FPOp->getValueAPF(),
+ /*roundTowardZero=*/false, Ty);
case Intrinsic::x86_sse_cvttss2si:
case Intrinsic::x86_sse_cvttss2si64:
case Intrinsic::x86_sse2_cvttsd2si:
case Intrinsic::x86_sse2_cvttsd2si64:
- if (ConstantFP *FPOp = dyn_cast<ConstantFP>(Op->getOperand(0)))
- return ConstantFoldConvertToInt(FPOp, /*roundTowardZero=*/true, Ty);
+ if (ConstantFP *FPOp =
+ dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
+ return ConstantFoldConvertToInt(FPOp->getValueAPF(),
+ /*roundTowardZero=*/true, Ty);
}
}
if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
if (!Ty->isFloatTy() && !Ty->isDoubleTy())
return 0;
- double Op1V = Ty->isFloatTy() ?
+ double Op1V = Ty->isFloatTy() ?
(double)Op1->getValueAPF().convertToFloat() :
Op1->getValueAPF().convertToDouble();
if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
if (Op2->getType() != Op1->getType())
return 0;
- double Op2V = Ty->isFloatTy() ?
+ double Op2V = Ty->isFloatTy() ?
(double)Op2->getValueAPF().convertToFloat():
Op2->getValueAPF().convertToDouble();
}
return 0;
}
-
+
if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
switch (F->getIntrinsicID()) {
APInt Res;
bool Overflow;
switch (F->getIntrinsicID()) {
- default: assert(0 && "Invalid case");
+ default: llvm_unreachable("Invalid case");
case Intrinsic::sadd_with_overflow:
Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow);
break;
return ConstantInt::get(Ty, Op1->getValue().countLeadingZeros());
}
}
-
+
return 0;
}
return 0;