-//===- ConstantFolding.cpp - LLVM constant folder -------------------------===//
+//===- ConstantFold.cpp - LLVM constant folder ----------------------------===//
//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements folding of constants for LLVM. This implements the
-// (internal) ConstantFolding.h interface, which is used by the
+// (internal) ConstantFold.h interface, which is used by the
// ConstantExpr::get* methods to automatically fold constants when possible.
//
// The current constant folding implementation is implemented in two pieces: the
//
//===----------------------------------------------------------------------===//
-#include "ConstantFolding.h"
+#include "ConstantFold.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
+#include "llvm/GlobalAlias.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/ManagedStatic.h"
// ConstantFold*Instruction Implementations
//===----------------------------------------------------------------------===//
-/// CastConstantPacked - Convert the specified ConstantPacked node to the
-/// specified packed type. At this point, we know that the elements of the
-/// input packed constant are all simple integer or FP values.
-static Constant *CastConstantPacked(ConstantPacked *CP,
- const PackedType *DstTy) {
- unsigned SrcNumElts = CP->getType()->getNumElements();
- unsigned DstNumElts = DstTy->getNumElements();
- const Type *SrcEltTy = CP->getType()->getElementType();
- const Type *DstEltTy = DstTy->getElementType();
+/// BitCastConstantVector - Convert the specified ConstantVector node to the
+/// specified vector type. At this point, we know that the elements of the
+/// input vector constant are all simple integer or FP values.
+static Constant *BitCastConstantVector(ConstantVector *CV,
+ const VectorType *DstTy) {
+ // If this cast changes element count then we can't handle it here:
+ // doing so requires endianness information. This should be handled by
+ // Analysis/ConstantFolding.cpp
+ unsigned NumElts = DstTy->getNumElements();
+ if (NumElts != CV->getNumOperands())
+ return 0;
- // If both vectors have the same number of elements (thus, the elements
- // are the same size), perform the conversion now.
- if (SrcNumElts == DstNumElts) {
- std::vector<Constant*> Result;
-
- // If the src and dest elements are both integers, or both floats, we can
- // just BitCast each element because the elements are the same size.
- if ((SrcEltTy->isIntegral() && DstEltTy->isIntegral()) ||
- (SrcEltTy->isFloatingPoint() && DstEltTy->isFloatingPoint())) {
- for (unsigned i = 0; i != SrcNumElts; ++i)
- Result.push_back(
- ConstantExpr::getBitCast(CP->getOperand(i), DstEltTy));
- return ConstantPacked::get(Result);
- }
-
- // If this is an int-to-fp cast ..
- if (SrcEltTy->isIntegral()) {
- // Ensure that it is int-to-fp cast
- assert(DstEltTy->isFloatingPoint());
- if (DstEltTy->getTypeID() == Type::DoubleTyID) {
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- double V =
- BitsToDouble(cast<ConstantInt>(CP->getOperand(i))->getZExtValue());
- Result.push_back(ConstantFP::get(Type::DoubleTy, V));
- }
- return ConstantPacked::get(Result);
- }
- assert(DstEltTy == Type::FloatTy && "Unknown fp type!");
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- float V =
- BitsToFloat(cast<ConstantInt>(CP->getOperand(i))->getZExtValue());
- Result.push_back(ConstantFP::get(Type::FloatTy, V));
- }
- return ConstantPacked::get(Result);
- }
-
- // Otherwise, this is an fp-to-int cast.
- assert(SrcEltTy->isFloatingPoint() && DstEltTy->isIntegral());
-
- if (SrcEltTy->getTypeID() == Type::DoubleTyID) {
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- uint64_t V =
- DoubleToBits(cast<ConstantFP>(CP->getOperand(i))->getValue());
- Constant *C = ConstantInt::get(Type::Int64Ty, V);
- Result.push_back(ConstantExpr::getBitCast(C, DstEltTy ));
- }
- return ConstantPacked::get(Result);
- }
-
- assert(SrcEltTy->getTypeID() == Type::FloatTyID);
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- uint32_t V = FloatToBits(cast<ConstantFP>(CP->getOperand(i))->getValue());
- Constant *C = ConstantInt::get(Type::Int32Ty, V);
- Result.push_back(ConstantExpr::getBitCast(C, DstEltTy));
- }
- return ConstantPacked::get(Result);
+ // Check to verify that all elements of the input are simple.
+ for (unsigned i = 0; i != NumElts; ++i) {
+ if (!isa<ConstantInt>(CV->getOperand(i)) &&
+ !isa<ConstantFP>(CV->getOperand(i)))
+ return 0;
}
-
- // Otherwise, this is a cast that changes element count and size. Handle
- // casts which shrink the elements here.
-
- // FIXME: We need to know endianness to do this!
-
- return 0;
+
+ // Bitcast each element now.
+ std::vector<Constant*> Result;
+ const Type *DstEltTy = DstTy->getElementType();
+ for (unsigned i = 0; i != NumElts; ++i)
+ Result.push_back(ConstantExpr::getBitCast(CV->getOperand(i), DstEltTy));
+ return ConstantVector::get(Result);
}
/// This function determines which opcode to use to fold two constant cast
/// expressions together. It uses CastInst::isEliminableCastPair to determine
/// the opcode. Consequently its just a wrapper around that function.
-/// @Determine if it is valid to fold a cast of a cast
+/// @brief Determine if it is valid to fold a cast of a cast
static unsigned
foldConstantCastPair(
unsigned opc, ///< opcode of the second cast constant expression
Type::Int64Ty);
}
-Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
- const Type *DestTy) {
+static Constant *FoldBitCast(Constant *V, const Type *DestTy) {
const Type *SrcTy = V->getType();
+ if (SrcTy == DestTy)
+ return V; // no-op cast
+
+ // Check to see if we are casting a pointer to an aggregate to a pointer to
+ // the first element. If so, return the appropriate GEP instruction.
+ if (const PointerType *PTy = dyn_cast<PointerType>(V->getType()))
+ if (const PointerType *DPTy = dyn_cast<PointerType>(DestTy))
+ if (PTy->getAddressSpace() == DPTy->getAddressSpace()) {
+ SmallVector<Value*, 8> IdxList;
+ IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
+ const Type *ElTy = PTy->getElementType();
+ while (ElTy != DPTy->getElementType()) {
+ if (const StructType *STy = dyn_cast<StructType>(ElTy)) {
+ if (STy->getNumElements() == 0) break;
+ ElTy = STy->getElementType(0);
+ IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
+ } else if (const SequentialType *STy =
+ dyn_cast<SequentialType>(ElTy)) {
+ if (isa<PointerType>(ElTy)) break; // Can't index into pointers!
+ ElTy = STy->getElementType();
+ IdxList.push_back(IdxList[0]);
+ } else {
+ break;
+ }
+ }
+
+ if (ElTy == DPTy->getElementType())
+ return ConstantExpr::getGetElementPtr(V, &IdxList[0], IdxList.size());
+ }
+
+ // Handle casts from one vector constant to another. We know that the src
+ // and dest type have the same size (otherwise its an illegal cast).
+ if (const VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
+ if (const VectorType *SrcTy = dyn_cast<VectorType>(V->getType())) {
+ assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
+ "Not cast between same sized vectors!");
+ SrcTy = NULL;
+ // First, check for null. Undef is already handled.
+ if (isa<ConstantAggregateZero>(V))
+ return Constant::getNullValue(DestTy);
+
+ if (ConstantVector *CV = dyn_cast<ConstantVector>(V))
+ return BitCastConstantVector(CV, DestPTy);
+ }
+
+ // Canonicalize scalar-to-vector bitcasts into vector-to-vector bitcasts
+ // This allows for other simplifications (although some of them
+ // can only be handled by Analysis/ConstantFolding.cpp).
+ if (isa<ConstantInt>(V) || isa<ConstantFP>(V))
+ return ConstantExpr::getBitCast(ConstantVector::get(&V, 1), DestPTy);
+ }
+
+ // Finally, implement bitcast folding now. The code below doesn't handle
+ // bitcast right.
+ if (isa<ConstantPointerNull>(V)) // ptr->ptr cast.
+ return ConstantPointerNull::get(cast<PointerType>(DestTy));
+
+ // Handle integral constant input.
+ if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ if (DestTy->isInteger())
+ // Integral -> Integral. This is a no-op because the bit widths must
+ // be the same. Consequently, we just fold to V.
+ return V;
+
+ if (DestTy->isFloatingPoint())
+ return ConstantFP::get(APFloat(CI->getValue(),
+ DestTy != Type::PPC_FP128Ty));
+
+ // Otherwise, can't fold this (vector?)
+ return 0;
+ }
+
+ // Handle ConstantFP input.
+ if (const ConstantFP *FP = dyn_cast<ConstantFP>(V))
+ // FP -> Integral.
+ return ConstantInt::get(FP->getValueAPF().bitcastToAPInt());
+
+ return 0;
+}
+
- if (isa<UndefValue>(V))
+Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
+ const Type *DestTy) {
+ if (isa<UndefValue>(V)) {
+ // zext(undef) = 0, because the top bits will be zero.
+ // sext(undef) = 0, because the top bits will all be the same.
+ // [us]itofp(undef) = 0, because the result value is bounded.
+ if (opc == Instruction::ZExt || opc == Instruction::SExt ||
+ opc == Instruction::UIToFP || opc == Instruction::SIToFP)
+ return Constant::getNullValue(DestTy);
return UndefValue::get(DestTy);
+ }
+ // No compile-time operations on this type yet.
+ if (V->getType() == Type::PPC_FP128Ty || DestTy == Type::PPC_FP128Ty)
+ return 0;
// If the cast operand is a constant expression, there's a few things we can
// do to try to simplify it.
}
}
+ // If the cast operand is a constant vector, perform the cast by
+ // operating on each element. In the cast of bitcasts, the element
+ // count may be mismatched; don't attempt to handle that here.
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(V))
+ if (isa<VectorType>(DestTy) &&
+ cast<VectorType>(DestTy)->getNumElements() ==
+ CV->getType()->getNumElements()) {
+ std::vector<Constant*> res;
+ const VectorType *DestVecTy = cast<VectorType>(DestTy);
+ const Type *DstEltTy = DestVecTy->getElementType();
+ for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
+ res.push_back(ConstantExpr::getCast(opc,
+ CV->getOperand(i), DstEltTy));
+ return ConstantVector::get(DestVecTy, res);
+ }
+
// We actually have to do a cast now. Perform the cast according to the
// opcode specified.
switch (opc) {
case Instruction::FPTrunc:
case Instruction::FPExt:
- if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V))
- return ConstantFP::get(DestTy, FPC->getValue());
+ if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
+ bool ignored;
+ APFloat Val = FPC->getValueAPF();
+ Val.convert(DestTy == Type::FloatTy ? APFloat::IEEEsingle :
+ DestTy == Type::DoubleTy ? APFloat::IEEEdouble :
+ DestTy == Type::X86_FP80Ty ? APFloat::x87DoubleExtended :
+ DestTy == Type::FP128Ty ? APFloat::IEEEquad :
+ APFloat::Bogus,
+ APFloat::rmNearestTiesToEven, &ignored);
+ return ConstantFP::get(Val);
+ }
return 0; // Can't fold.
case Instruction::FPToUI:
- if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V))
- return ConstantInt::get(DestTy,(uint64_t) FPC->getValue());
- return 0; // Can't fold.
case Instruction::FPToSI:
- if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V))
- return ConstantInt::get(DestTy,(int64_t) FPC->getValue());
+ if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
+ const APFloat &V = FPC->getValueAPF();
+ bool ignored;
+ uint64_t x[2];
+ uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ (void) V.convertToInteger(x, DestBitWidth, opc==Instruction::FPToSI,
+ APFloat::rmTowardZero, &ignored);
+ APInt Val(DestBitWidth, 2, x);
+ return ConstantInt::get(Val);
+ }
return 0; // Can't fold.
case Instruction::IntToPtr: //always treated as unsigned
if (V->isNullValue()) // Is it an integral null value?
return ConstantInt::get(DestTy, 0);
return 0; // Other pointer types cannot be casted
case Instruction::UIToFP:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
- return ConstantFP::get(DestTy, double(CI->getZExtValue()));
- return 0;
case Instruction::SIToFP:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
- return ConstantFP::get(DestTy, double(CI->getSExtValue()));
+ if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ APInt api = CI->getValue();
+ const uint64_t zero[] = {0, 0};
+ APFloat apf = APFloat(APInt(DestTy->getPrimitiveSizeInBits(),
+ 2, zero));
+ (void)apf.convertFromAPInt(api,
+ opc==Instruction::SIToFP,
+ APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(apf);
+ }
return 0;
case Instruction::ZExt:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
- return ConstantInt::get(DestTy, CI->getZExtValue());
+ if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ APInt Result(CI->getValue());
+ Result.zext(BitWidth);
+ return ConstantInt::get(Result);
+ }
return 0;
case Instruction::SExt:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V))
- return ConstantInt::get(DestTy, CI->getSExtValue());
+ if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
+ uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ APInt Result(CI->getValue());
+ Result.sext(BitWidth);
+ return ConstantInt::get(Result);
+ }
return 0;
case Instruction::Trunc:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) // Can't trunc a bool
- return ConstantInt::get(DestTy, CI->getZExtValue());
- return 0;
- case Instruction::BitCast:
- if (SrcTy == DestTy)
- return (Constant*)V; // no-op cast
-
- // Check to see if we are casting a pointer to an aggregate to a pointer to
- // the first element. If so, return the appropriate GEP instruction.
- if (const PointerType *PTy = dyn_cast<PointerType>(V->getType()))
- if (const PointerType *DPTy = dyn_cast<PointerType>(DestTy)) {
- std::vector<Value*> IdxList;
- IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
- const Type *ElTy = PTy->getElementType();
- while (ElTy != DPTy->getElementType()) {
- if (const StructType *STy = dyn_cast<StructType>(ElTy)) {
- if (STy->getNumElements() == 0) break;
- ElTy = STy->getElementType(0);
- IdxList.push_back(Constant::getNullValue(Type::Int32Ty));
- } else if (const SequentialType *STy =
- dyn_cast<SequentialType>(ElTy)) {
- if (isa<PointerType>(ElTy)) break; // Can't index into pointers!
- ElTy = STy->getElementType();
- IdxList.push_back(IdxList[0]);
- } else {
- break;
- }
- }
-
- if (ElTy == DPTy->getElementType())
- return ConstantExpr::getGetElementPtr(
- const_cast<Constant*>(V),IdxList);
- }
-
- // Handle casts from one packed constant to another. We know that the src
- // and dest type have the same size (otherwise its an illegal cast).
- if (const PackedType *DestPTy = dyn_cast<PackedType>(DestTy)) {
- if (const PackedType *SrcTy = dyn_cast<PackedType>(V->getType())) {
- assert(DestPTy->getBitWidth() == SrcTy->getBitWidth() &&
- "Not cast between same sized vectors!");
- // First, check for null and undef
- if (isa<ConstantAggregateZero>(V))
- return Constant::getNullValue(DestTy);
- if (isa<UndefValue>(V))
- return UndefValue::get(DestTy);
-
- if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(V)) {
- // This is a cast from a ConstantPacked of one type to a
- // ConstantPacked of another type. Check to see if all elements of
- // the input are simple.
- bool AllSimpleConstants = true;
- for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i) {
- if (!isa<ConstantInt>(CP->getOperand(i)) &&
- !isa<ConstantFP>(CP->getOperand(i))) {
- AllSimpleConstants = false;
- break;
- }
- }
-
- // If all of the elements are simple constants, we can fold this.
- if (AllSimpleConstants)
- return CastConstantPacked(const_cast<ConstantPacked*>(CP), DestPTy);
- }
- }
- }
-
- // Finally, implement bitcast folding now. The code below doesn't handle
- // bitcast right.
- if (isa<ConstantPointerNull>(V)) // ptr->ptr cast.
- return ConstantPointerNull::get(cast<PointerType>(DestTy));
-
- // Handle integral constant input.
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- // Integral -> Integral, must be changing sign.
- if (DestTy->isIntegral())
- return ConstantInt::get(DestTy, CI->getZExtValue());
-
- if (DestTy->isFloatingPoint()) {
- if (DestTy == Type::FloatTy)
- return ConstantFP::get(DestTy, BitsToFloat(CI->getZExtValue()));
- assert(DestTy == Type::DoubleTy && "Unknown FP type!");
- return ConstantFP::get(DestTy, BitsToDouble(CI->getZExtValue()));
- }
- // Otherwise, can't fold this (packed?)
- return 0;
- }
-
- // Handle ConstantFP input.
- if (const ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
- // FP -> Integral.
- if (DestTy->isIntegral()) {
- if (DestTy == Type::Int32Ty)
- return ConstantInt::get(DestTy, FloatToBits(FP->getValue()));
- assert(DestTy == Type::Int64Ty &&
- "Incorrect integer type for bitcast!");
- return ConstantInt::get(DestTy, DoubleToBits(FP->getValue()));
- }
+ uint32_t BitWidth = cast<IntegerType>(DestTy)->getBitWidth();
+ APInt Result(CI->getValue());
+ Result.trunc(BitWidth);
+ return ConstantInt::get(Result);
}
return 0;
+ case Instruction::BitCast:
+ return FoldBitCast(const_cast<Constant*>(V), DestTy);
default:
assert(!"Invalid CE CastInst opcode");
break;
Constant *llvm::ConstantFoldExtractElementInstruction(const Constant *Val,
const Constant *Idx) {
if (isa<UndefValue>(Val)) // ee(undef, x) -> undef
- return UndefValue::get(cast<PackedType>(Val->getType())->getElementType());
+ return UndefValue::get(cast<VectorType>(Val->getType())->getElementType());
if (Val->isNullValue()) // ee(zero, x) -> zero
return Constant::getNullValue(
- cast<PackedType>(Val->getType())->getElementType());
+ cast<VectorType>(Val->getType())->getElementType());
- if (const ConstantPacked *CVal = dyn_cast<ConstantPacked>(Val)) {
+ if (const ConstantVector *CVal = dyn_cast<ConstantVector>(Val)) {
if (const ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx)) {
- return const_cast<Constant*>(CVal->getOperand(CIdx->getZExtValue()));
+ return CVal->getOperand(CIdx->getZExtValue());
} else if (isa<UndefValue>(Idx)) {
// ee({w,x,y,z}, undef) -> w (an arbitrary value).
- return const_cast<Constant*>(CVal->getOperand(0));
+ return CVal->getOperand(0);
}
}
return 0;
const Constant *Idx) {
const ConstantInt *CIdx = dyn_cast<ConstantInt>(Idx);
if (!CIdx) return 0;
- uint64_t idxVal = CIdx->getZExtValue();
+ APInt idxVal = CIdx->getValue();
if (isa<UndefValue>(Val)) {
- // Insertion of scalar constant into packed undef
+ // Insertion of scalar constant into vector undef
// Optimize away insertion of undef
if (isa<UndefValue>(Elt))
return const_cast<Constant*>(Val);
// Otherwise break the aggregate undef into multiple undefs and do
// the insertion
unsigned numOps =
- cast<PackedType>(Val->getType())->getNumElements();
+ cast<VectorType>(Val->getType())->getNumElements();
std::vector<Constant*> Ops;
Ops.reserve(numOps);
for (unsigned i = 0; i < numOps; ++i) {
const Constant *Op =
- (i == idxVal) ? Elt : UndefValue::get(Elt->getType());
+ (idxVal == i) ? Elt : UndefValue::get(Elt->getType());
Ops.push_back(const_cast<Constant*>(Op));
}
- return ConstantPacked::get(Ops);
+ return ConstantVector::get(Ops);
}
if (isa<ConstantAggregateZero>(Val)) {
- // Insertion of scalar constant into packed aggregate zero
+ // Insertion of scalar constant into vector aggregate zero
// Optimize away insertion of zero
if (Elt->isNullValue())
return const_cast<Constant*>(Val);
// Otherwise break the aggregate zero into multiple zeros and do
// the insertion
unsigned numOps =
- cast<PackedType>(Val->getType())->getNumElements();
+ cast<VectorType>(Val->getType())->getNumElements();
std::vector<Constant*> Ops;
Ops.reserve(numOps);
for (unsigned i = 0; i < numOps; ++i) {
const Constant *Op =
- (i == idxVal) ? Elt : Constant::getNullValue(Elt->getType());
+ (idxVal == i) ? Elt : Constant::getNullValue(Elt->getType());
Ops.push_back(const_cast<Constant*>(Op));
}
- return ConstantPacked::get(Ops);
+ return ConstantVector::get(Ops);
}
- if (const ConstantPacked *CVal = dyn_cast<ConstantPacked>(Val)) {
- // Insertion of scalar constant into packed constant
+ if (const ConstantVector *CVal = dyn_cast<ConstantVector>(Val)) {
+ // Insertion of scalar constant into vector constant
std::vector<Constant*> Ops;
Ops.reserve(CVal->getNumOperands());
for (unsigned i = 0; i < CVal->getNumOperands(); ++i) {
const Constant *Op =
- (i == idxVal) ? Elt : cast<Constant>(CVal->getOperand(i));
+ (idxVal == i) ? Elt : cast<Constant>(CVal->getOperand(i));
Ops.push_back(const_cast<Constant*>(Op));
}
- return ConstantPacked::get(Ops);
+ return ConstantVector::get(Ops);
}
+
+ return 0;
+}
+
+/// GetVectorElement - If C is a ConstantVector, ConstantAggregateZero or Undef
+/// return the specified element value. Otherwise return null.
+static Constant *GetVectorElement(const Constant *C, unsigned EltNo) {
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(C))
+ return CV->getOperand(EltNo);
+
+ const Type *EltTy = cast<VectorType>(C->getType())->getElementType();
+ if (isa<ConstantAggregateZero>(C))
+ return Constant::getNullValue(EltTy);
+ if (isa<UndefValue>(C))
+ return UndefValue::get(EltTy);
return 0;
}
Constant *llvm::ConstantFoldShuffleVectorInstruction(const Constant *V1,
const Constant *V2,
const Constant *Mask) {
- // TODO:
+ // Undefined shuffle mask -> undefined value.
+ if (isa<UndefValue>(Mask)) return UndefValue::get(V1->getType());
+
+ unsigned MaskNumElts = cast<VectorType>(Mask->getType())->getNumElements();
+ unsigned SrcNumElts = cast<VectorType>(V1->getType())->getNumElements();
+ const Type *EltTy = cast<VectorType>(V1->getType())->getElementType();
+
+ // Loop over the shuffle mask, evaluating each element.
+ SmallVector<Constant*, 32> Result;
+ for (unsigned i = 0; i != MaskNumElts; ++i) {
+ Constant *InElt = GetVectorElement(Mask, i);
+ if (InElt == 0) return 0;
+
+ if (isa<UndefValue>(InElt))
+ InElt = UndefValue::get(EltTy);
+ else if (ConstantInt *CI = dyn_cast<ConstantInt>(InElt)) {
+ unsigned Elt = CI->getZExtValue();
+ if (Elt >= SrcNumElts*2)
+ InElt = UndefValue::get(EltTy);
+ else if (Elt >= SrcNumElts)
+ InElt = GetVectorElement(V2, Elt - SrcNumElts);
+ else
+ InElt = GetVectorElement(V1, Elt);
+ if (InElt == 0) return 0;
+ } else {
+ // Unknown value.
+ return 0;
+ }
+ Result.push_back(InElt);
+ }
+
+ return ConstantVector::get(&Result[0], Result.size());
+}
+
+Constant *llvm::ConstantFoldExtractValueInstruction(const Constant *Agg,
+ const unsigned *Idxs,
+ unsigned NumIdx) {
+ // Base case: no indices, so return the entire value.
+ if (NumIdx == 0)
+ return const_cast<Constant *>(Agg);
+
+ if (isa<UndefValue>(Agg)) // ev(undef, x) -> undef
+ return UndefValue::get(ExtractValueInst::getIndexedType(Agg->getType(),
+ Idxs,
+ Idxs + NumIdx));
+
+ if (isa<ConstantAggregateZero>(Agg)) // ev(0, x) -> 0
+ return
+ Constant::getNullValue(ExtractValueInst::getIndexedType(Agg->getType(),
+ Idxs,
+ Idxs + NumIdx));
+
+ // Otherwise recurse.
+ return ConstantFoldExtractValueInstruction(Agg->getOperand(*Idxs),
+ Idxs+1, NumIdx-1);
+}
+
+Constant *llvm::ConstantFoldInsertValueInstruction(const Constant *Agg,
+ const Constant *Val,
+ const unsigned *Idxs,
+ unsigned NumIdx) {
+ // Base case: no indices, so replace the entire value.
+ if (NumIdx == 0)
+ return const_cast<Constant *>(Val);
+
+ if (isa<UndefValue>(Agg)) {
+ // Insertion of constant into aggregate undef
+ // Optimize away insertion of undef
+ if (isa<UndefValue>(Val))
+ return const_cast<Constant*>(Agg);
+ // Otherwise break the aggregate undef into multiple undefs and do
+ // the insertion
+ const CompositeType *AggTy = cast<CompositeType>(Agg->getType());
+ unsigned numOps;
+ if (const ArrayType *AR = dyn_cast<ArrayType>(AggTy))
+ numOps = AR->getNumElements();
+ else
+ numOps = cast<StructType>(AggTy)->getNumElements();
+ std::vector<Constant*> Ops(numOps);
+ for (unsigned i = 0; i < numOps; ++i) {
+ const Type *MemberTy = AggTy->getTypeAtIndex(i);
+ const Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(UndefValue::get(MemberTy),
+ Val, Idxs+1, NumIdx-1) :
+ UndefValue::get(MemberTy);
+ Ops[i] = const_cast<Constant*>(Op);
+ }
+ if (isa<StructType>(AggTy))
+ return ConstantStruct::get(Ops);
+ else
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
+ }
+ if (isa<ConstantAggregateZero>(Agg)) {
+ // Insertion of constant into aggregate zero
+ // Optimize away insertion of zero
+ if (Val->isNullValue())
+ return const_cast<Constant*>(Agg);
+ // Otherwise break the aggregate zero into multiple zeros and do
+ // the insertion
+ const CompositeType *AggTy = cast<CompositeType>(Agg->getType());
+ unsigned numOps;
+ if (const ArrayType *AR = dyn_cast<ArrayType>(AggTy))
+ numOps = AR->getNumElements();
+ else
+ numOps = cast<StructType>(AggTy)->getNumElements();
+ std::vector<Constant*> Ops(numOps);
+ for (unsigned i = 0; i < numOps; ++i) {
+ const Type *MemberTy = AggTy->getTypeAtIndex(i);
+ const Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(Constant::getNullValue(MemberTy),
+ Val, Idxs+1, NumIdx-1) :
+ Constant::getNullValue(MemberTy);
+ Ops[i] = const_cast<Constant*>(Op);
+ }
+ if (isa<StructType>(AggTy))
+ return ConstantStruct::get(Ops);
+ else
+ return ConstantArray::get(cast<ArrayType>(AggTy), Ops);
+ }
+ if (isa<ConstantStruct>(Agg) || isa<ConstantArray>(Agg)) {
+ // Insertion of constant into aggregate constant
+ std::vector<Constant*> Ops(Agg->getNumOperands());
+ for (unsigned i = 0; i < Agg->getNumOperands(); ++i) {
+ const Constant *Op =
+ (*Idxs == i) ?
+ ConstantFoldInsertValueInstruction(Agg->getOperand(i),
+ Val, Idxs+1, NumIdx-1) :
+ Agg->getOperand(i);
+ Ops[i] = const_cast<Constant*>(Op);
+ }
+ Constant *C;
+ if (isa<StructType>(Agg->getType()))
+ C = ConstantStruct::get(Ops);
+ else
+ C = ConstantArray::get(cast<ArrayType>(Agg->getType()), Ops);
+ return C;
+ }
+
return 0;
}
-/// EvalVectorOp - Given two packed constants and a function pointer, apply the
-/// function pointer to each element pair, producing a new ConstantPacked
-/// constant.
-static Constant *EvalVectorOp(const ConstantPacked *V1,
- const ConstantPacked *V2,
+/// EvalVectorOp - Given two vector constants and a function pointer, apply the
+/// function pointer to each element pair, producing a new ConstantVector
+/// constant. Either or both of V1 and V2 may be NULL, meaning a
+/// ConstantAggregateZero operand.
+static Constant *EvalVectorOp(const ConstantVector *V1,
+ const ConstantVector *V2,
+ const VectorType *VTy,
Constant *(*FP)(Constant*, Constant*)) {
std::vector<Constant*> Res;
- for (unsigned i = 0, e = V1->getNumOperands(); i != e; ++i)
- Res.push_back(FP(const_cast<Constant*>(V1->getOperand(i)),
- const_cast<Constant*>(V2->getOperand(i))));
- return ConstantPacked::get(Res);
+ const Type *EltTy = VTy->getElementType();
+ for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) {
+ const Constant *C1 = V1 ? V1->getOperand(i) : Constant::getNullValue(EltTy);
+ const Constant *C2 = V2 ? V2->getOperand(i) : Constant::getNullValue(EltTy);
+ Res.push_back(FP(const_cast<Constant*>(C1),
+ const_cast<Constant*>(C2)));
+ }
+ return ConstantVector::get(Res);
}
Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode,
const Constant *C1,
const Constant *C2) {
+ // No compile-time operations on this type yet.
+ if (C1->getType() == Type::PPC_FP128Ty)
+ return 0;
+
// Handle UndefValue up front
if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) {
switch (Opcode) {
+ case Instruction::Xor:
+ if (isa<UndefValue>(C1) && isa<UndefValue>(C2))
+ // Handle undef ^ undef -> 0 special case. This is a common
+ // idiom (misuse).
+ return Constant::getNullValue(C1->getType());
+ // Fallthrough
case Instruction::Add:
case Instruction::Sub:
- case Instruction::Xor:
return UndefValue::get(C1->getType());
case Instruction::Mul:
case Instruction::And:
return Constant::getNullValue(C1->getType());
case Instruction::UDiv:
case Instruction::SDiv:
- case Instruction::FDiv:
case Instruction::URem:
case Instruction::SRem:
- case Instruction::FRem:
if (!isa<UndefValue>(C2)) // undef / X -> 0
return Constant::getNullValue(C1->getType());
return const_cast<Constant*>(C2); // X / undef -> undef
case Instruction::Or: // X | undef -> -1
- if (const PackedType *PTy = dyn_cast<PackedType>(C1->getType()))
- return ConstantPacked::getAllOnesValue(PTy);
+ if (const VectorType *PTy = dyn_cast<VectorType>(C1->getType()))
+ return ConstantVector::getAllOnesValue(PTy);
return ConstantInt::getAllOnesValue(C1->getType());
case Instruction::LShr:
if (isa<UndefValue>(C2) && isa<UndefValue>(C1))
}
}
- if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
- if (isa<ConstantExpr>(C2)) {
- // There are many possible foldings we could do here. We should probably
- // at least fold add of a pointer with an integer into the appropriate
- // getelementptr. This will improve alias analysis a bit.
- } else {
- // Just implement a couple of simple identities.
+ // Handle simplifications when the RHS is a constant int.
+ if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
+ switch (Opcode) {
+ case Instruction::Add:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X + 0 == X
+ break;
+ case Instruction::Sub:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X - 0 == X
+ break;
+ case Instruction::Mul:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C2); // X * 0 == 0
+ if (CI2->equalsInt(1))
+ return const_cast<Constant*>(C1); // X * 1 == X
+ break;
+ case Instruction::UDiv:
+ case Instruction::SDiv:
+ if (CI2->equalsInt(1))
+ return const_cast<Constant*>(C1); // X / 1 == X
+ if (CI2->equalsInt(0))
+ return UndefValue::get(CI2->getType()); // X / 0 == undef
+ break;
+ case Instruction::URem:
+ case Instruction::SRem:
+ if (CI2->equalsInt(1))
+ return Constant::getNullValue(CI2->getType()); // X % 1 == 0
+ if (CI2->equalsInt(0))
+ return UndefValue::get(CI2->getType()); // X % 0 == undef
+ break;
+ case Instruction::And:
+ if (CI2->isZero()) return const_cast<Constant*>(C2); // X & 0 == 0
+ if (CI2->isAllOnesValue())
+ return const_cast<Constant*>(C1); // X & -1 == X
+
+ if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) {
+ // (zext i32 to i64) & 4294967295 -> (zext i32 to i64)
+ if (CE1->getOpcode() == Instruction::ZExt) {
+ unsigned DstWidth = CI2->getType()->getBitWidth();
+ unsigned SrcWidth =
+ CE1->getOperand(0)->getType()->getPrimitiveSizeInBits();
+ APInt PossiblySetBits(APInt::getLowBitsSet(DstWidth, SrcWidth));
+ if ((PossiblySetBits & CI2->getValue()) == PossiblySetBits)
+ return const_cast<Constant*>(C1);
+ }
+
+ // If and'ing the address of a global with a constant, fold it.
+ if (CE1->getOpcode() == Instruction::PtrToInt &&
+ isa<GlobalValue>(CE1->getOperand(0))) {
+ GlobalValue *GV = cast<GlobalValue>(CE1->getOperand(0));
+
+ // Functions are at least 4-byte aligned.
+ unsigned GVAlign = GV->getAlignment();
+ if (isa<Function>(GV))
+ GVAlign = std::max(GVAlign, 4U);
+
+ if (GVAlign > 1) {
+ unsigned DstWidth = CI2->getType()->getBitWidth();
+ unsigned SrcWidth = std::min(DstWidth, Log2_32(GVAlign));
+ APInt BitsNotSet(APInt::getLowBitsSet(DstWidth, SrcWidth));
+
+ // If checking bits we know are clear, return zero.
+ if ((CI2->getValue() & BitsNotSet) == CI2->getValue())
+ return Constant::getNullValue(CI2->getType());
+ }
+ }
+ }
+ break;
+ case Instruction::Or:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X | 0 == X
+ if (CI2->isAllOnesValue())
+ return const_cast<Constant*>(C2); // X | -1 == -1
+ break;
+ case Instruction::Xor:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X ^ 0 == X
+ break;
+ case Instruction::AShr:
+ // ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
+ if (const ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1))
+ if (CE1->getOpcode() == Instruction::ZExt) // Top bits known zero.
+ return ConstantExpr::getLShr(const_cast<Constant*>(C1),
+ const_cast<Constant*>(C2));
+ break;
+ }
+ }
+
+ // At this point we know neither constant is an UndefValue.
+ if (const ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
+ if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
+ using namespace APIntOps;
+ const APInt &C1V = CI1->getValue();
+ const APInt &C2V = CI2->getValue();
switch (Opcode) {
- case Instruction::Add:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X + 0 == X
- break;
- case Instruction::Sub:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X - 0 == X
- break;
- case Instruction::Mul:
- if (C2->isNullValue()) return const_cast<Constant*>(C2); // X * 0 == 0
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->getZExtValue() == 1)
- return const_cast<Constant*>(C1); // X * 1 == X
+ default:
break;
+ case Instruction::Add:
+ return ConstantInt::get(C1V + C2V);
+ case Instruction::Sub:
+ return ConstantInt::get(C1V - C2V);
+ case Instruction::Mul:
+ return ConstantInt::get(C1V * C2V);
case Instruction::UDiv:
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ return ConstantInt::get(C1V.udiv(C2V));
case Instruction::SDiv:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->getZExtValue() == 1)
- return const_cast<Constant*>(C1); // X / 1 == X
- break;
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
+ return UndefValue::get(CI1->getType()); // MIN_INT / -1 -> undef
+ return ConstantInt::get(C1V.sdiv(C2V));
case Instruction::URem:
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ return ConstantInt::get(C1V.urem(C2V));
case Instruction::SRem:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->getZExtValue() == 1)
- return Constant::getNullValue(CI->getType()); // X % 1 == 0
- break;
+ assert(!CI2->isNullValue() && "Div by zero handled above");
+ if (C2V.isAllOnesValue() && C1V.isMinSignedValue())
+ return UndefValue::get(CI1->getType()); // MIN_INT % -1 -> undef
+ return ConstantInt::get(C1V.srem(C2V));
case Instruction::And:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->isAllOnesValue())
- return const_cast<Constant*>(C1); // X & -1 == X
- if (C2->isNullValue()) return const_cast<Constant*>(C2); // X & 0 == 0
- if (CE1->isCast() && isa<GlobalValue>(CE1->getOperand(0))) {
- GlobalValue *CPR = cast<GlobalValue>(CE1->getOperand(0));
-
- // Functions are at least 4-byte aligned. If and'ing the address of a
- // function with a constant < 4, fold it to zero.
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->getZExtValue() < 4 && isa<Function>(CPR))
- return Constant::getNullValue(CI->getType());
- }
- break;
+ return ConstantInt::get(C1V & C2V);
case Instruction::Or:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X | 0 == X
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->isAllOnesValue())
- return const_cast<Constant*>(C2); // X | -1 == -1
- break;
+ return ConstantInt::get(C1V | C2V);
case Instruction::Xor:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X ^ 0 == X
+ return ConstantInt::get(C1V ^ C2V);
+ case Instruction::Shl: {
+ uint32_t shiftAmt = C2V.getZExtValue();
+ if (shiftAmt < C1V.getBitWidth())
+ return ConstantInt::get(C1V.shl(shiftAmt));
+ else
+ return UndefValue::get(C1->getType()); // too big shift is undef
+ }
+ case Instruction::LShr: {
+ uint32_t shiftAmt = C2V.getZExtValue();
+ if (shiftAmt < C1V.getBitWidth())
+ return ConstantInt::get(C1V.lshr(shiftAmt));
+ else
+ return UndefValue::get(C1->getType()); // too big shift is undef
+ }
+ case Instruction::AShr: {
+ uint32_t shiftAmt = C2V.getZExtValue();
+ if (shiftAmt < C1V.getBitWidth())
+ return ConstantInt::get(C1V.ashr(shiftAmt));
+ else
+ return UndefValue::get(C1->getType()); // too big shift is undef
+ }
+ }
+ }
+
+ switch (Opcode) {
+ case Instruction::SDiv:
+ case Instruction::UDiv:
+ case Instruction::URem:
+ case Instruction::SRem:
+ case Instruction::LShr:
+ case Instruction::AShr:
+ case Instruction::Shl:
+ if (CI1->equalsInt(0)) return const_cast<Constant*>(C1);
+ break;
+ default:
+ break;
+ }
+ } else if (const ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
+ if (const ConstantFP *CFP2 = dyn_cast<ConstantFP>(C2)) {
+ APFloat C1V = CFP1->getValueAPF();
+ APFloat C2V = CFP2->getValueAPF();
+ APFloat C3V = C1V; // copy for modification
+ switch (Opcode) {
+ default:
+ break;
+ case Instruction::FAdd:
+ (void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::FSub:
+ (void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::FMul:
+ (void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::FDiv:
+ (void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ case Instruction::FRem:
+ (void)C3V.mod(C2V, APFloat::rmNearestTiesToEven);
+ return ConstantFP::get(C3V);
+ }
+ }
+ } else if (const VectorType *VTy = dyn_cast<VectorType>(C1->getType())) {
+ const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1);
+ const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2);
+ if ((CP1 != NULL || isa<ConstantAggregateZero>(C1)) &&
+ (CP2 != NULL || isa<ConstantAggregateZero>(C2))) {
+ switch (Opcode) {
+ default:
break;
+ case Instruction::Add:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAdd);
+ case Instruction::FAdd:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFAdd);
+ case Instruction::Sub:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSub);
+ case Instruction::FSub:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFSub);
+ case Instruction::Mul:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getMul);
+ case Instruction::FMul:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFMul);
+ case Instruction::UDiv:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getUDiv);
+ case Instruction::SDiv:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSDiv);
+ case Instruction::FDiv:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFDiv);
+ case Instruction::URem:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getURem);
+ case Instruction::SRem:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSRem);
+ case Instruction::FRem:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getFRem);
+ case Instruction::And:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAnd);
+ case Instruction::Or:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getOr);
+ case Instruction::Xor:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getXor);
+ case Instruction::LShr:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getLShr);
+ case Instruction::AShr:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAShr);
+ case Instruction::Shl:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getShl);
}
}
+ }
+
+ if (isa<ConstantExpr>(C1)) {
+ // There are many possible foldings we could do here. We should probably
+ // at least fold add of a pointer with an integer into the appropriate
+ // getelementptr. This will improve alias analysis a bit.
} else if (isa<ConstantExpr>(C2)) {
// If C2 is a constant expr and C1 isn't, flop them around and fold the
// other way if possible.
switch (Opcode) {
case Instruction::Add:
+ case Instruction::FAdd:
case Instruction::Mul:
+ case Instruction::FMul:
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
// No change of opcode required.
return ConstantFoldBinaryInstruction(Opcode, C2, C1);
-
+
case Instruction::Shl:
case Instruction::LShr:
case Instruction::AShr:
case Instruction::Sub:
+ case Instruction::FSub:
case Instruction::SDiv:
case Instruction::UDiv:
case Instruction::FDiv:
case Instruction::SRem:
case Instruction::FRem:
default: // These instructions cannot be flopped around.
- return 0;
- }
- }
-
- // At this point we know neither constant is an UndefValue nor a ConstantExpr
- // so look at directly computing the value.
- if (const ConstantInt *CI1 = dyn_cast<ConstantInt>(C1)) {
- if (const ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) {
- if (CI1->getType() == Type::Int1Ty && CI2->getType() == Type::Int1Ty) {
- switch (Opcode) {
- default:
- break;
- case Instruction::And:
- return ConstantInt::get(Type::Int1Ty,
- CI1->getZExtValue() & CI2->getZExtValue());
- case Instruction::Or:
- return ConstantInt::get(Type::Int1Ty,
- CI1->getZExtValue() | CI2->getZExtValue());
- case Instruction::Xor:
- return ConstantInt::get(Type::Int1Ty,
- CI1->getZExtValue() ^ CI2->getZExtValue());
- }
- } else {
- uint64_t C1Val = CI1->getZExtValue();
- uint64_t C2Val = CI2->getZExtValue();
- switch (Opcode) {
- default:
- break;
- case Instruction::Add:
- return ConstantInt::get(C1->getType(), C1Val + C2Val);
- case Instruction::Sub:
- return ConstantInt::get(C1->getType(), C1Val - C2Val);
- case Instruction::Mul:
- return ConstantInt::get(C1->getType(), C1Val * C2Val);
- case Instruction::UDiv:
- if (CI2->isNullValue()) // X / 0 -> can't fold
- return 0;
- return ConstantInt::get(C1->getType(), C1Val / C2Val);
- case Instruction::SDiv:
- if (CI2->isNullValue()) return 0; // X / 0 -> can't fold
- if (CI2->isAllOnesValue() &&
- (((CI1->getType()->getPrimitiveSizeInBits() == 64) &&
- (CI1->getSExtValue() == INT64_MIN)) ||
- (CI1->getSExtValue() == -CI1->getSExtValue())))
- return 0; // MIN_INT / -1 -> overflow
- return ConstantInt::get(C1->getType(),
- CI1->getSExtValue() / CI2->getSExtValue());
- case Instruction::URem:
- if (C2->isNullValue()) return 0; // X / 0 -> can't fold
- return ConstantInt::get(C1->getType(), C1Val % C2Val);
- case Instruction::SRem:
- if (CI2->isNullValue()) return 0; // X % 0 -> can't fold
- if (CI2->isAllOnesValue() &&
- (((CI1->getType()->getPrimitiveSizeInBits() == 64) &&
- (CI1->getSExtValue() == INT64_MIN)) ||
- (CI1->getSExtValue() == -CI1->getSExtValue())))
- return 0; // MIN_INT % -1 -> overflow
- return ConstantInt::get(C1->getType(),
- CI1->getSExtValue() % CI2->getSExtValue());
- case Instruction::And:
- return ConstantInt::get(C1->getType(), C1Val & C2Val);
- case Instruction::Or:
- return ConstantInt::get(C1->getType(), C1Val | C2Val);
- case Instruction::Xor:
- return ConstantInt::get(C1->getType(), C1Val ^ C2Val);
- case Instruction::Shl:
- return ConstantInt::get(C1->getType(), C1Val << C2Val);
- case Instruction::LShr:
- return ConstantInt::get(C1->getType(), C1Val >> C2Val);
- case Instruction::AShr:
- return ConstantInt::get(C1->getType(),
- CI1->getSExtValue() >> C2Val);
- }
- }
- }
- } else if (const ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
- if (const ConstantFP *CFP2 = dyn_cast<ConstantFP>(C2)) {
- double C1Val = CFP1->getValue();
- double C2Val = CFP2->getValue();
- switch (Opcode) {
- default:
- break;
- case Instruction::Add:
- return ConstantFP::get(CFP1->getType(), C1Val + C2Val);
- case Instruction::Sub:
- return ConstantFP::get(CFP1->getType(), C1Val - C2Val);
- case Instruction::Mul:
- return ConstantFP::get(CFP1->getType(), C1Val * C2Val);
- case Instruction::FDiv:
- if (CFP2->isExactlyValue(0.0))
- return ConstantFP::get(CFP1->getType(),
- std::numeric_limits<double>::infinity());
- if (CFP2->isExactlyValue(-0.0))
- return ConstantFP::get(CFP1->getType(),
- -std::numeric_limits<double>::infinity());
- return ConstantFP::get(CFP1->getType(), C1Val / C2Val);
- case Instruction::FRem:
- if (CFP2->isNullValue())
- return 0;
- return ConstantFP::get(CFP1->getType(), std::fmod(C1Val, C2Val));
- }
- }
- } else if (const ConstantPacked *CP1 = dyn_cast<ConstantPacked>(C1)) {
- if (const ConstantPacked *CP2 = dyn_cast<ConstantPacked>(C2)) {
- switch (Opcode) {
- default:
- break;
- case Instruction::Add:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getAdd);
- case Instruction::Sub:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getSub);
- case Instruction::Mul:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getMul);
- case Instruction::UDiv:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getUDiv);
- case Instruction::SDiv:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getSDiv);
- case Instruction::FDiv:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getFDiv);
- case Instruction::URem:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getURem);
- case Instruction::SRem:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getSRem);
- case Instruction::FRem:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getFRem);
- case Instruction::And:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getAnd);
- case Instruction::Or:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getOr);
- case Instruction::Xor:
- return EvalVectorOp(CP1, CP2, ConstantExpr::getXor);
- }
+ break;
}
}
-
- // We don't know how to fold this
+
+ // We don't know how to fold this.
return 0;
}
const Constant *V2) {
assert(V1->getType() == V2->getType() &&
"Cannot compare values of different types!");
+
+ // No compile-time operations on this type yet.
+ if (V1->getType() == Type::PPC_FP128Ty)
+ return FCmpInst::BAD_FCMP_PREDICATE;
+
// Handle degenerate case quickly
if (V1 == V2) return FCmpInst::FCMP_OEQ;
Constant *C2 = const_cast<Constant*>(V2);
R = dyn_cast<ConstantInt>(
ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ, C1, C2));
- if (R && R->getZExtValue())
+ if (R && !R->isZero())
return FCmpInst::FCMP_OEQ;
R = dyn_cast<ConstantInt>(
ConstantExpr::getFCmp(FCmpInst::FCMP_OLT, C1, C2));
- if (R && R->getZExtValue())
+ if (R && !R->isZero())
return FCmpInst::FCMP_OLT;
R = dyn_cast<ConstantInt>(
ConstantExpr::getFCmp(FCmpInst::FCMP_OGT, C1, C2));
- if (R && R->getZExtValue())
+ if (R && !R->isZero())
return FCmpInst::FCMP_OGT;
// Nothing more we can do
Constant *C2 = const_cast<Constant*>(V2);
ICmpInst::Predicate pred = ICmpInst::ICMP_EQ;
R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
- if (R && R->getZExtValue())
+ if (R && !R->isZero())
return pred;
pred = isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
- if (R && R->getZExtValue())
+ if (R && !R->isZero())
return pred;
- pred = isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
+ pred = isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
R = dyn_cast<ConstantInt>(ConstantExpr::getICmp(pred, C1, C2));
- if (R && R->getZExtValue())
+ if (R && !R->isZero())
return pred;
// If we couldn't figure it out, bail.
// Now we know that the RHS is a GlobalValue or simple constant,
// which (since the types must match) means that it's a ConstantPointerNull.
if (const GlobalValue *CPR2 = dyn_cast<GlobalValue>(V2)) {
- if (!CPR1->hasExternalWeakLinkage() || !CPR2->hasExternalWeakLinkage())
- return ICmpInst::ICMP_NE;
+ // Don't try to decide equality of aliases.
+ if (!isa<GlobalAlias>(CPR1) && !isa<GlobalAlias>(CPR2))
+ if (!CPR1->hasExternalWeakLinkage() || !CPR2->hasExternalWeakLinkage())
+ return ICmpInst::ICMP_NE;
} else {
- // GlobalVals can never be null.
assert(isa<ConstantPointerNull>(V2) && "Canonicalization guarantee!");
- if (!CPR1->hasExternalWeakLinkage())
+ // GlobalVals can never be null. Don't try to evaluate aliases.
+ if (!CPR1->hasExternalWeakLinkage() && !isa<GlobalAlias>(CPR1))
return ICmpInst::ICMP_NE;
}
} else {
case Instruction::UIToFP:
case Instruction::SIToFP:
- case Instruction::IntToPtr:
case Instruction::BitCast:
case Instruction::ZExt:
case Instruction::SExt:
- case Instruction::PtrToInt:
// If the cast is not actually changing bits, and the second operand is a
// null pointer, do the comparison with the pre-casted value.
if (V2->isNullValue() &&
- (isa<PointerType>(CE1->getType()) || CE1->getType()->isIntegral())) {
- bool sgnd = CE1->getOpcode() == Instruction::ZExt ? false :
- (CE1->getOpcode() == Instruction::SExt ? true :
- (CE1->getOpcode() == Instruction::PtrToInt ? false : isSigned));
- return evaluateICmpRelation(
- CE1Op0, Constant::getNullValue(CE1Op0->getType()), sgnd);
+ (isa<PointerType>(CE1->getType()) || CE1->getType()->isInteger())) {
+ bool sgnd = isSigned;
+ if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
+ if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
+ return evaluateICmpRelation(CE1Op0,
+ Constant::getNullValue(CE1Op0->getType()),
+ sgnd);
}
// If the dest type is a pointer type, and the RHS is a constantexpr cast
if (const ConstantExpr *CE2 = dyn_cast<ConstantExpr>(V2))
if (CE2->isCast() && isa<PointerType>(CE1->getType()) &&
CE1->getOperand(0)->getType() == CE2->getOperand(0)->getType() &&
- CE1->getOperand(0)->getType()->isIntegral()) {
- bool sgnd = CE1->getOpcode() == Instruction::ZExt ? false :
- (CE1->getOpcode() == Instruction::SExt ? true :
- (CE1->getOpcode() == Instruction::PtrToInt ? false : isSigned));
+ CE1->getOperand(0)->getType()->isInteger()) {
+ bool sgnd = isSigned;
+ if (CE1->getOpcode() == Instruction::ZExt) isSigned = false;
+ if (CE1->getOpcode() == Instruction::SExt) isSigned = true;
return evaluateICmpRelation(CE1->getOperand(0), CE2->getOperand(0),
- sgnd);
+ sgnd);
}
break;
// Ok, we ran out of things they have in common. If any leftovers
// are non-zero then we have a difference, otherwise we are equal.
for (; i < CE1->getNumOperands(); ++i)
- if (!CE1->getOperand(i)->isNullValue())
+ if (!CE1->getOperand(i)->isNullValue()) {
if (isa<ConstantInt>(CE1->getOperand(i)))
return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
else
return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
+ }
for (; i < CE2->getNumOperands(); ++i)
- if (!CE2->getOperand(i)->isNullValue())
+ if (!CE2->getOperand(i)->isNullValue()) {
if (isa<ConstantInt>(CE2->getOperand(i)))
return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
else
return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal.
+ }
return ICmpInst::ICMP_EQ;
}
}
Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
const Constant *C1,
const Constant *C2) {
+ const Type *ResultTy;
+ if (const VectorType *VT = dyn_cast<VectorType>(C1->getType()))
+ ResultTy = VectorType::get(Type::Int1Ty, VT->getNumElements());
+ else
+ ResultTy = Type::Int1Ty;
+
+ // Fold FCMP_FALSE/FCMP_TRUE unconditionally.
+ if (pred == FCmpInst::FCMP_FALSE)
+ return Constant::getNullValue(ResultTy);
+
+ if (pred == FCmpInst::FCMP_TRUE)
+ return Constant::getAllOnesValue(ResultTy);
// Handle some degenerate cases first
if (isa<UndefValue>(C1) || isa<UndefValue>(C2))
- return UndefValue::get(Type::Int1Ty);
+ return UndefValue::get(ResultTy);
+
+ // No compile-time operations on this type yet.
+ if (C1->getType() == Type::PPC_FP128Ty)
+ return 0;
// icmp eq/ne(null,GV) -> false/true
if (C1->isNullValue()) {
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C2))
- if (!GV->hasExternalWeakLinkage()) // External weak GV can be null
+ // Don't try to evaluate aliases. External weak GV can be null.
+ if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) {
if (pred == ICmpInst::ICMP_EQ)
return ConstantInt::getFalse();
else if (pred == ICmpInst::ICMP_NE)
return ConstantInt::getTrue();
+ }
// icmp eq/ne(GV,null) -> false/true
} else if (C2->isNullValue()) {
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C1))
- if (!GV->hasExternalWeakLinkage()) // External weak GV can be null
+ // Don't try to evaluate aliases. External weak GV can be null.
+ if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) {
if (pred == ICmpInst::ICMP_EQ)
return ConstantInt::getFalse();
else if (pred == ICmpInst::ICMP_NE)
return ConstantInt::getTrue();
+ }
}
- if (isa<ConstantInt>(C1) && isa<ConstantInt>(C2) &&
- C1->getType() == Type::Int1Ty && C2->getType() == Type::Int1Ty) {
- bool C1Val = cast<ConstantInt>(C1)->getZExtValue();
- bool C2Val = cast<ConstantInt>(C2)->getZExtValue();
+ if (isa<ConstantInt>(C1) && isa<ConstantInt>(C2)) {
+ APInt V1 = cast<ConstantInt>(C1)->getValue();
+ APInt V2 = cast<ConstantInt>(C2)->getValue();
switch (pred) {
default: assert(0 && "Invalid ICmp Predicate"); return 0;
- case ICmpInst::ICMP_EQ:
- return ConstantInt::get(Type::Int1Ty, C1Val == C2Val);
- case ICmpInst::ICMP_NE:
- return ConstantInt::get(Type::Int1Ty, C1Val != C2Val);
- case ICmpInst::ICMP_ULT:
- return ConstantInt::get(Type::Int1Ty, C1Val < C2Val);
- case ICmpInst::ICMP_UGT:
- return ConstantInt::get(Type::Int1Ty, C1Val > C2Val);
- case ICmpInst::ICMP_ULE:
- return ConstantInt::get(Type::Int1Ty, C1Val <= C2Val);
- case ICmpInst::ICMP_UGE:
- return ConstantInt::get(Type::Int1Ty, C1Val >= C2Val);
- case ICmpInst::ICMP_SLT:
- return ConstantInt::get(Type::Int1Ty, C1Val < C2Val);
- case ICmpInst::ICMP_SGT:
- return ConstantInt::get(Type::Int1Ty, C1Val > C2Val);
- case ICmpInst::ICMP_SLE:
- return ConstantInt::get(Type::Int1Ty, C1Val <= C2Val);
- case ICmpInst::ICMP_SGE:
- return ConstantInt::get(Type::Int1Ty, C1Val >= C2Val);
- }
- } else if (isa<ConstantInt>(C1) && isa<ConstantInt>(C2)) {
- if (ICmpInst::isSignedPredicate(ICmpInst::Predicate(pred))) {
- int64_t V1 = cast<ConstantInt>(C1)->getSExtValue();
- int64_t V2 = cast<ConstantInt>(C2)->getSExtValue();
- switch (pred) {
- default: assert(0 && "Invalid ICmp Predicate"); return 0;
- case ICmpInst::ICMP_SLT:return ConstantInt::get(Type::Int1Ty, V1 < V2);
- case ICmpInst::ICMP_SGT:return ConstantInt::get(Type::Int1Ty, V1 > V2);
- case ICmpInst::ICMP_SLE:return ConstantInt::get(Type::Int1Ty, V1 <= V2);
- case ICmpInst::ICMP_SGE:return ConstantInt::get(Type::Int1Ty, V1 >= V2);
- }
- } else {
- uint64_t V1 = cast<ConstantInt>(C1)->getZExtValue();
- uint64_t V2 = cast<ConstantInt>(C2)->getZExtValue();
- switch (pred) {
- default: assert(0 && "Invalid ICmp Predicate"); return 0;
- case ICmpInst::ICMP_EQ: return ConstantInt::get(Type::Int1Ty, V1 == V2);
- case ICmpInst::ICMP_NE: return ConstantInt::get(Type::Int1Ty, V1 != V2);
- case ICmpInst::ICMP_ULT:return ConstantInt::get(Type::Int1Ty, V1 < V2);
- case ICmpInst::ICMP_UGT:return ConstantInt::get(Type::Int1Ty, V1 > V2);
- case ICmpInst::ICMP_ULE:return ConstantInt::get(Type::Int1Ty, V1 <= V2);
- case ICmpInst::ICMP_UGE:return ConstantInt::get(Type::Int1Ty, V1 >= V2);
- }
+ case ICmpInst::ICMP_EQ: return ConstantInt::get(Type::Int1Ty, V1 == V2);
+ case ICmpInst::ICMP_NE: return ConstantInt::get(Type::Int1Ty, V1 != V2);
+ case ICmpInst::ICMP_SLT:return ConstantInt::get(Type::Int1Ty, V1.slt(V2));
+ case ICmpInst::ICMP_SGT:return ConstantInt::get(Type::Int1Ty, V1.sgt(V2));
+ case ICmpInst::ICMP_SLE:return ConstantInt::get(Type::Int1Ty, V1.sle(V2));
+ case ICmpInst::ICMP_SGE:return ConstantInt::get(Type::Int1Ty, V1.sge(V2));
+ case ICmpInst::ICMP_ULT:return ConstantInt::get(Type::Int1Ty, V1.ult(V2));
+ case ICmpInst::ICMP_UGT:return ConstantInt::get(Type::Int1Ty, V1.ugt(V2));
+ case ICmpInst::ICMP_ULE:return ConstantInt::get(Type::Int1Ty, V1.ule(V2));
+ case ICmpInst::ICMP_UGE:return ConstantInt::get(Type::Int1Ty, V1.uge(V2));
}
} else if (isa<ConstantFP>(C1) && isa<ConstantFP>(C2)) {
- double C1Val = cast<ConstantFP>(C1)->getValue();
- double C2Val = cast<ConstantFP>(C2)->getValue();
+ APFloat C1V = cast<ConstantFP>(C1)->getValueAPF();
+ APFloat C2V = cast<ConstantFP>(C2)->getValueAPF();
+ APFloat::cmpResult R = C1V.compare(C2V);
switch (pred) {
default: assert(0 && "Invalid FCmp Predicate"); return 0;
case FCmpInst::FCMP_FALSE: return ConstantInt::getFalse();
case FCmpInst::FCMP_TRUE: return ConstantInt::getTrue();
case FCmpInst::FCMP_UNO:
- return ConstantInt::get(Type::Int1Ty, C1Val != C1Val || C2Val != C2Val);
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered);
case FCmpInst::FCMP_ORD:
- return ConstantInt::get(Type::Int1Ty, C1Val == C1Val && C2Val == C2Val);
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpUnordered);
case FCmpInst::FCMP_UEQ:
- if (C1Val != C1Val || C2Val != C2Val)
- return ConstantInt::getTrue();
- /* FALL THROUGH */
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpEqual);
case FCmpInst::FCMP_OEQ:
- return ConstantInt::get(Type::Int1Ty, C1Val == C2Val);
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpEqual);
case FCmpInst::FCMP_UNE:
- if (C1Val != C1Val || C2Val != C2Val)
- return ConstantInt::getTrue();
- /* FALL THROUGH */
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpEqual);
case FCmpInst::FCMP_ONE:
- return ConstantInt::get(Type::Int1Ty, C1Val != C2Val);
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
+ R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_ULT:
- if (C1Val != C1Val || C2Val != C2Val)
- return ConstantInt::getTrue();
- /* FALL THROUGH */
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpLessThan);
case FCmpInst::FCMP_OLT:
- return ConstantInt::get(Type::Int1Ty, C1Val < C2Val);
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan);
case FCmpInst::FCMP_UGT:
- if (C1Val != C1Val || C2Val != C2Val)
- return ConstantInt::getTrue();
- /* FALL THROUGH */
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpUnordered ||
+ R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_OGT:
- return ConstantInt::get(Type::Int1Ty, C1Val > C2Val);
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan);
case FCmpInst::FCMP_ULE:
- if (C1Val != C1Val || C2Val != C2Val)
- return ConstantInt::getTrue();
- /* FALL THROUGH */
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpGreaterThan);
case FCmpInst::FCMP_OLE:
- return ConstantInt::get(Type::Int1Ty, C1Val <= C2Val);
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpLessThan ||
+ R==APFloat::cmpEqual);
case FCmpInst::FCMP_UGE:
- if (C1Val != C1Val || C2Val != C2Val)
- return ConstantInt::getTrue();
- /* FALL THROUGH */
+ return ConstantInt::get(Type::Int1Ty, R!=APFloat::cmpLessThan);
case FCmpInst::FCMP_OGE:
- return ConstantInt::get(Type::Int1Ty, C1Val >= C2Val);
+ return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan ||
+ R==APFloat::cmpEqual);
}
- } else if (const ConstantPacked *CP1 = dyn_cast<ConstantPacked>(C1)) {
- if (const ConstantPacked *CP2 = dyn_cast<ConstantPacked>(C2)) {
- if (pred == FCmpInst::FCMP_OEQ || pred == FCmpInst::FCMP_UEQ) {
- for (unsigned i = 0, e = CP1->getNumOperands(); i != e; ++i) {
- Constant *C= ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ,
- const_cast<Constant*>(CP1->getOperand(i)),
- const_cast<Constant*>(CP2->getOperand(i)));
- if (ConstantInt *CB = dyn_cast<ConstantInt>(C))
- return CB;
- }
- // Otherwise, could not decide from any element pairs.
- return 0;
- } else if (pred == ICmpInst::ICMP_EQ) {
- for (unsigned i = 0, e = CP1->getNumOperands(); i != e; ++i) {
- Constant *C = ConstantExpr::getICmp(ICmpInst::ICMP_EQ,
- const_cast<Constant*>(CP1->getOperand(i)),
- const_cast<Constant*>(CP2->getOperand(i)));
- if (ConstantInt *CB = dyn_cast<ConstantInt>(C))
- return CB;
- }
- // Otherwise, could not decide from any element pairs.
- return 0;
- }
+ } else if (isa<VectorType>(C1->getType())) {
+ SmallVector<Constant*, 16> C1Elts, C2Elts;
+ C1->getVectorElements(C1Elts);
+ C2->getVectorElements(C2Elts);
+
+ // If we can constant fold the comparison of each element, constant fold
+ // the whole vector comparison.
+ SmallVector<Constant*, 4> ResElts;
+ for (unsigned i = 0, e = C1Elts.size(); i != e; ++i) {
+ // Compare the elements, producing an i1 result or constant expr.
+ ResElts.push_back(ConstantExpr::getCompare(pred, C1Elts[i], C2Elts[i]));
}
+ return ConstantVector::get(&ResElts[0], ResElts.size());
}
if (C1->getType()->isFloatingPoint()) {
+ int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
switch (evaluateFCmpRelation(C1, C2)) {
default: assert(0 && "Unknown relation!");
case FCmpInst::FCMP_UNO:
case FCmpInst::BAD_FCMP_PREDICATE:
break; // Couldn't determine anything about these constants.
case FCmpInst::FCMP_OEQ: // We know that C1 == C2
- return ConstantInt::get(Type::Int1Ty,
- pred == FCmpInst::FCMP_UEQ || pred == FCmpInst::FCMP_OEQ ||
- pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE ||
- pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ Result = (pred == FCmpInst::FCMP_UEQ || pred == FCmpInst::FCMP_OEQ ||
+ pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE ||
+ pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ break;
case FCmpInst::FCMP_OLT: // We know that C1 < C2
- return ConstantInt::get(Type::Int1Ty,
- pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
- pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT ||
- pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE);
+ Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
+ pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT ||
+ pred == FCmpInst::FCMP_ULE || pred == FCmpInst::FCMP_OLE);
+ break;
case FCmpInst::FCMP_OGT: // We know that C1 > C2
- return ConstantInt::get(Type::Int1Ty,
- pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
- pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT ||
- pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ Result = (pred == FCmpInst::FCMP_UNE || pred == FCmpInst::FCMP_ONE ||
+ pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT ||
+ pred == FCmpInst::FCMP_UGE || pred == FCmpInst::FCMP_OGE);
+ break;
case FCmpInst::FCMP_OLE: // We know that C1 <= C2
// We can only partially decide this relation.
if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
- return ConstantInt::getFalse();
- if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
- return ConstantInt::getTrue();
+ Result = 0;
+ else if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
+ Result = 1;
break;
case FCmpInst::FCMP_OGE: // We known that C1 >= C2
// We can only partially decide this relation.
if (pred == FCmpInst::FCMP_ULT || pred == FCmpInst::FCMP_OLT)
- return ConstantInt::getFalse();
- if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
- return ConstantInt::getTrue();
+ Result = 0;
+ else if (pred == FCmpInst::FCMP_UGT || pred == FCmpInst::FCMP_OGT)
+ Result = 1;
break;
case ICmpInst::ICMP_NE: // We know that C1 != C2
// We can only partially decide this relation.
if (pred == FCmpInst::FCMP_OEQ || pred == FCmpInst::FCMP_UEQ)
- return ConstantInt::getFalse();
- if (pred == FCmpInst::FCMP_ONE || pred == FCmpInst::FCMP_UNE)
- return ConstantInt::getTrue();
+ Result = 0;
+ else if (pred == FCmpInst::FCMP_ONE || pred == FCmpInst::FCMP_UNE)
+ Result = 1;
break;
}
+
+ // If we evaluated the result, return it now.
+ if (Result != -1)
+ return ConstantInt::get(Type::Int1Ty, Result);
+
} else {
// Evaluate the relation between the two constants, per the predicate.
+ int Result = -1; // -1 = unknown, 0 = known false, 1 = known true.
switch (evaluateICmpRelation(C1, C2, CmpInst::isSigned(pred))) {
default: assert(0 && "Unknown relational!");
case ICmpInst::BAD_ICMP_PREDICATE:
case ICmpInst::ICMP_EQ: // We know the constants are equal!
// If we know the constants are equal, we can decide the result of this
// computation precisely.
- return ConstantInt::get(Type::Int1Ty,
- pred == ICmpInst::ICMP_EQ ||
- pred == ICmpInst::ICMP_ULE ||
- pred == ICmpInst::ICMP_SLE ||
- pred == ICmpInst::ICMP_UGE ||
- pred == ICmpInst::ICMP_SGE);
+ Result = (pred == ICmpInst::ICMP_EQ ||
+ pred == ICmpInst::ICMP_ULE ||
+ pred == ICmpInst::ICMP_SLE ||
+ pred == ICmpInst::ICMP_UGE ||
+ pred == ICmpInst::ICMP_SGE);
+ break;
case ICmpInst::ICMP_ULT:
// If we know that C1 < C2, we can decide the result of this computation
// precisely.
- return ConstantInt::get(Type::Int1Ty,
- pred == ICmpInst::ICMP_ULT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_ULE);
+ Result = (pred == ICmpInst::ICMP_ULT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_ULE);
+ break;
case ICmpInst::ICMP_SLT:
// If we know that C1 < C2, we can decide the result of this computation
// precisely.
- return ConstantInt::get(Type::Int1Ty,
- pred == ICmpInst::ICMP_SLT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_SLE);
+ Result = (pred == ICmpInst::ICMP_SLT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_SLE);
+ break;
case ICmpInst::ICMP_UGT:
// If we know that C1 > C2, we can decide the result of this computation
// precisely.
- return ConstantInt::get(Type::Int1Ty,
- pred == ICmpInst::ICMP_UGT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_UGE);
+ Result = (pred == ICmpInst::ICMP_UGT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_UGE);
+ break;
case ICmpInst::ICMP_SGT:
// If we know that C1 > C2, we can decide the result of this computation
// precisely.
- return ConstantInt::get(Type::Int1Ty,
- pred == ICmpInst::ICMP_SGT ||
- pred == ICmpInst::ICMP_NE ||
- pred == ICmpInst::ICMP_SGE);
+ Result = (pred == ICmpInst::ICMP_SGT ||
+ pred == ICmpInst::ICMP_NE ||
+ pred == ICmpInst::ICMP_SGE);
+ break;
case ICmpInst::ICMP_ULE:
// If we know that C1 <= C2, we can only partially decide this relation.
- if (pred == ICmpInst::ICMP_UGT) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_ULT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_UGT) Result = 0;
+ if (pred == ICmpInst::ICMP_ULT) Result = 1;
break;
case ICmpInst::ICMP_SLE:
// If we know that C1 <= C2, we can only partially decide this relation.
- if (pred == ICmpInst::ICMP_SGT) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_SLT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_SGT) Result = 0;
+ if (pred == ICmpInst::ICMP_SLT) Result = 1;
break;
case ICmpInst::ICMP_UGE:
// If we know that C1 >= C2, we can only partially decide this relation.
- if (pred == ICmpInst::ICMP_ULT) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_UGT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_ULT) Result = 0;
+ if (pred == ICmpInst::ICMP_UGT) Result = 1;
break;
case ICmpInst::ICMP_SGE:
// If we know that C1 >= C2, we can only partially decide this relation.
- if (pred == ICmpInst::ICMP_SLT) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_SGT) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_SLT) Result = 0;
+ if (pred == ICmpInst::ICMP_SGT) Result = 1;
break;
case ICmpInst::ICMP_NE:
// If we know that C1 != C2, we can only partially decide this relation.
- if (pred == ICmpInst::ICMP_EQ) return ConstantInt::getFalse();
- if (pred == ICmpInst::ICMP_NE) return ConstantInt::getTrue();
+ if (pred == ICmpInst::ICMP_EQ) Result = 0;
+ if (pred == ICmpInst::ICMP_NE) Result = 1;
break;
}
-
+
+ // If we evaluated the result, return it now.
+ if (Result != -1)
+ return ConstantInt::get(Type::Int1Ty, Result);
+
if (!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) {
- // If C2 is a constant expr and C1 isn't, flop them around and fold the
+ // If C2 is a constant expr and C1 isn't, flip them around and fold the
// other way if possible.
switch (pred) {
case ICmpInst::ICMP_EQ:
}
}
return 0;
-}
+ }
Constant *llvm::ConstantFoldGetElementPtr(const Constant *C,
- const std::vector<Value*> &IdxList) {
- if (IdxList.size() == 0 ||
- (IdxList.size() == 1 && cast<Constant>(IdxList[0])->isNullValue()))
+ Constant* const *Idxs,
+ unsigned NumIdx) {
+ if (NumIdx == 0 ||
+ (NumIdx == 1 && Idxs[0]->isNullValue()))
return const_cast<Constant*>(C);
if (isa<UndefValue>(C)) {
- const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), IdxList,
- true);
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
+ (Value **)Idxs,
+ (Value **)Idxs+NumIdx);
assert(Ty != 0 && "Invalid indices for GEP!");
- return UndefValue::get(PointerType::get(Ty));
+ return UndefValue::get(PointerType::get(Ty, Ptr->getAddressSpace()));
}
- Constant *Idx0 = cast<Constant>(IdxList[0]);
+ Constant *Idx0 = Idxs[0];
if (C->isNullValue()) {
bool isNull = true;
- for (unsigned i = 0, e = IdxList.size(); i != e; ++i)
- if (!cast<Constant>(IdxList[i])->isNullValue()) {
+ for (unsigned i = 0, e = NumIdx; i != e; ++i)
+ if (!Idxs[i]->isNullValue()) {
isNull = false;
break;
}
if (isNull) {
- const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(), IdxList,
- true);
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
+ (Value**)Idxs,
+ (Value**)Idxs+NumIdx);
assert(Ty != 0 && "Invalid indices for GEP!");
- return ConstantPointerNull::get(PointerType::get(Ty));
- }
-
- if (IdxList.size() == 1) {
- const Type *ElTy = cast<PointerType>(C->getType())->getElementType();
- if (uint32_t ElSize = ElTy->getPrimitiveSize()) {
- // gep null, C is equal to C*sizeof(nullty). If nullty is a known llvm
- // type, we can statically fold this.
- Constant *R = ConstantInt::get(Type::Int32Ty, ElSize);
- // We know R is unsigned, Idx0 is signed because it must be an index
- // through a sequential type (gep pointer operand) which is always
- // signed.
- R = ConstantExpr::getSExtOrBitCast(R, Idx0->getType());
- R = ConstantExpr::getMul(R, Idx0); // signed multiply
- // R is a signed integer, C is the GEP pointer so -> IntToPtr
- return ConstantExpr::getIntToPtr(R, C->getType());
- }
+ return
+ ConstantPointerNull::get(PointerType::get(Ty,Ptr->getAddressSpace()));
}
}
LastTy = *I;
if ((LastTy && isa<ArrayType>(LastTy)) || Idx0->isNullValue()) {
- std::vector<Value*> NewIndices;
- NewIndices.reserve(IdxList.size() + CE->getNumOperands());
+ SmallVector<Value*, 16> NewIndices;
+ NewIndices.reserve(NumIdx + CE->getNumOperands());
for (unsigned i = 1, e = CE->getNumOperands()-1; i != e; ++i)
NewIndices.push_back(CE->getOperand(i));
}
NewIndices.push_back(Combined);
- NewIndices.insert(NewIndices.end(), IdxList.begin()+1, IdxList.end());
- return ConstantExpr::getGetElementPtr(CE->getOperand(0), NewIndices);
+ NewIndices.insert(NewIndices.end(), Idxs+1, Idxs+NumIdx);
+ return ConstantExpr::getGetElementPtr(CE->getOperand(0), &NewIndices[0],
+ NewIndices.size());
}
}
// long 0, long 0)
// To: int* getelementptr ([3 x int]* %X, long 0, long 0)
//
- if (CE->isCast() && IdxList.size() > 1 && Idx0->isNullValue())
+ if (CE->isCast() && NumIdx > 1 && Idx0->isNullValue()) {
if (const PointerType *SPT =
dyn_cast<PointerType>(CE->getOperand(0)->getType()))
if (const ArrayType *SAT = dyn_cast<ArrayType>(SPT->getElementType()))
dyn_cast<ArrayType>(cast<PointerType>(C->getType())->getElementType()))
if (CAT->getElementType() == SAT->getElementType())
return ConstantExpr::getGetElementPtr(
- (Constant*)CE->getOperand(0), IdxList);
+ (Constant*)CE->getOperand(0), Idxs, NumIdx);
+ }
+
+ // Fold: getelementptr (i8* inttoptr (i64 1 to i8*), i32 -1)
+ // Into: inttoptr (i64 0 to i8*)
+ // This happens with pointers to member functions in C++.
+ if (CE->getOpcode() == Instruction::IntToPtr && NumIdx == 1 &&
+ isa<ConstantInt>(CE->getOperand(0)) && isa<ConstantInt>(Idxs[0]) &&
+ cast<PointerType>(CE->getType())->getElementType() == Type::Int8Ty) {
+ Constant *Base = CE->getOperand(0);
+ Constant *Offset = Idxs[0];
+
+ // Convert the smaller integer to the larger type.
+ if (Offset->getType()->getPrimitiveSizeInBits() <
+ Base->getType()->getPrimitiveSizeInBits())
+ Offset = ConstantExpr::getSExt(Offset, Base->getType());
+ else if (Base->getType()->getPrimitiveSizeInBits() <
+ Offset->getType()->getPrimitiveSizeInBits())
+ Base = ConstantExpr::getZExt(Base, Offset->getType());
+
+ Base = ConstantExpr::getAdd(Base, Offset);
+ return ConstantExpr::getIntToPtr(Base, CE->getType());
+ }
}
return 0;
}
projects / oota-llvm.git / blobdiff