//
// 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.
//
//===----------------------------------------------------------------------===//
//
// ConstantFold*Instruction Implementations
//===----------------------------------------------------------------------===//
-/// CastConstantVector - Convert the specified ConstantVector node to the
+/// 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 *CastConstantVector(ConstantVector *CV,
- const VectorType *DstTy) {
- unsigned SrcNumElts = CV->getType()->getNumElements();
- unsigned DstNumElts = DstTy->getNumElements();
- const Type *SrcEltTy = CV->getType()->getElementType();
- const Type *DstEltTy = DstTy->getElementType();
+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->isInteger() && DstEltTy->isInteger()) ||
- (SrcEltTy->isFloatingPoint() && DstEltTy->isFloatingPoint())) {
- for (unsigned i = 0; i != SrcNumElts; ++i)
- Result.push_back(
- ConstantExpr::getBitCast(CV->getOperand(i), DstEltTy));
- return ConstantVector::get(Result);
- }
-
- // If this is an int-to-fp cast ..
- if (SrcEltTy->isInteger()) {
- // Ensure that it is int-to-fp cast
- assert(DstEltTy->isFloatingPoint());
- if (DstEltTy->getTypeID() == Type::DoubleTyID) {
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- ConstantInt *CI = cast<ConstantInt>(CV->getOperand(i));
- double V = CI->getValue().bitsToDouble();
- Result.push_back(ConstantFP::get(Type::DoubleTy, APFloat(V)));
- }
- return ConstantVector::get(Result);
- }
- assert(DstEltTy == Type::FloatTy && "Unknown fp type!");
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- ConstantInt *CI = cast<ConstantInt>(CV->getOperand(i));
- float V = CI->getValue().bitsToFloat();
- Result.push_back(ConstantFP::get(Type::FloatTy, APFloat(V)));
- }
- return ConstantVector::get(Result);
- }
-
- // Otherwise, this is an fp-to-int cast.
- assert(SrcEltTy->isFloatingPoint() && DstEltTy->isInteger());
-
- if (SrcEltTy->getTypeID() == Type::DoubleTyID) {
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- uint64_t V =
- DoubleToBits(cast<ConstantFP>(CV->getOperand(i))->
- getValueAPF().convertToDouble());
- Constant *C = ConstantInt::get(Type::Int64Ty, V);
- Result.push_back(ConstantExpr::getBitCast(C, DstEltTy ));
- }
- return ConstantVector::get(Result);
- }
-
- assert(SrcEltTy->getTypeID() == Type::FloatTyID);
- for (unsigned i = 0; i != SrcNumElts; ++i) {
- uint32_t V = FloatToBits(cast<ConstantFP>(CV->getOperand(i))->
- getValueAPF().convertToFloat());
- Constant *C = ConstantInt::get(Type::Int32Ty, V);
- Result.push_back(ConstantExpr::getBitCast(C, DstEltTy));
- }
- return ConstantVector::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
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!");
+ // 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);
+ }
+ }
+
+ // 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()) {
+ assert((DestTy == Type::DoubleTy || DestTy == Type::FloatTy) &&
+ "Unknown FP type!");
+ return ConstantFP::get(APFloat(CI->getValue()));
+ }
+ // Otherwise, can't fold this (vector?)
+ return 0;
+ }
+
+ // Handle ConstantFP input.
+ if (const ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
+ // FP -> Integral.
+ if (DestTy == Type::Int32Ty) {
+ return ConstantInt::get(FP->getValueAPF().convertToAPInt());
+ } else {
+ assert(DestTy == Type::Int64Ty && "only support f32/f64 for now!");
+ return ConstantInt::get(FP->getValueAPF().convertToAPInt());
+ }
+ }
+ return 0;
+}
+
+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.
- if (opc == Instruction::ZExt || opc == Instruction::SExt)
+ // [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.
case Instruction::FPTrunc:
case Instruction::FPExt:
if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
- APFloat Val = FPC->getValueAPF();
- Val.convert(DestTy==Type::FloatTy ? APFloat::IEEEsingle :
- APFloat::IEEEdouble,
+ 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);
- return ConstantFP::get(DestTy, Val);
+ return ConstantFP::get(Val);
}
return 0; // Can't fold.
case Instruction::FPToUI:
- if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
- APFloat V = FPC->getValueAPF();
- bool isDouble = &V.getSemantics()==&APFloat::IEEEdouble;
- uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
- APInt Val(APIntOps::RoundDoubleToAPInt(isDouble ? V.convertToDouble() :
- (double)V.convertToFloat(), DestBitWidth));
- return ConstantInt::get(Val);
- }
- return 0; // Can't fold.
case Instruction::FPToSI:
if (const ConstantFP *FPC = dyn_cast<ConstantFP>(V)) {
- APFloat V = FPC->getValueAPF();
- bool isDouble = &V.getSemantics()==&APFloat::IEEEdouble;
+ const APFloat &V = FPC->getValueAPF();
+ uint64_t x[2];
uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth();
- APInt Val(APIntOps::RoundDoubleToAPInt(isDouble ? V.convertToDouble() :
- (double)V.convertToFloat(), DestBitWidth));
+ (void) V.convertToInteger(x, DestBitWidth, opc==Instruction::FPToSI,
+ APFloat::rmTowardZero);
+ APInt Val(DestBitWidth, 2, x);
return ConstantInt::get(Val);
}
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
+ 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(ConstantFoldCastInstruction(opc, V->getOperand(i),
+ DstEltTy));
+ return ConstantVector::get(DestVecTy, res);
+ }
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)) {
- if (DestTy==Type::FloatTy)
- return ConstantFP::get(DestTy,
- APFloat((float)CI->getValue().roundToDouble()));
- else
- return ConstantFP::get(DestTy, APFloat(CI->getValue().roundToDouble()));
- }
- return 0;
case Instruction::SIToFP:
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- double d = CI->getValue().signedRoundToDouble();
- if (DestTy==Type::FloatTy)
- return ConstantFP::get(DestTy, APFloat((float)d));
- else
- return ConstantFP::get(DestTy, APFloat(d));
+ 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);
+ }
+ if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
+ 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(ConstantFoldCastInstruction(opc, V->getOperand(i),
+ DstEltTy));
+ return ConstantVector::get(DestVecTy, res);
}
return 0;
case Instruction::ZExt:
}
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)) {
- 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(
- const_cast<Constant*>(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!");
- // First, check for null and undef
- if (isa<ConstantAggregateZero>(V))
- return Constant::getNullValue(DestTy);
- if (isa<UndefValue>(V))
- return UndefValue::get(DestTy);
-
- if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
- // This is a cast from a ConstantVector of one type to a
- // ConstantVector of another type. Check to see if all elements of
- // the input are simple.
- bool AllSimpleConstants = true;
- for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) {
- if (!isa<ConstantInt>(CV->getOperand(i)) &&
- !isa<ConstantFP>(CV->getOperand(i))) {
- AllSimpleConstants = false;
- break;
- }
- }
-
- // If all of the elements are simple constants, we can fold this.
- if (AllSimpleConstants)
- return CastConstantVector(const_cast<ConstantVector*>(CV), 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 const_cast<Constant*>(V);
-
- if (DestTy->isFloatingPoint()) {
- if (DestTy == Type::FloatTy)
- return ConstantFP::get(DestTy, APFloat(CI->getValue().bitsToFloat()));
- assert(DestTy == Type::DoubleTy && "Unknown FP type!");
- return ConstantFP::get(DestTy, APFloat(CI->getValue().bitsToDouble()));
- }
- // Otherwise, can't fold this (vector?)
- return 0;
- }
-
- // Handle ConstantFP input.
- if (const ConstantFP *FP = dyn_cast<ConstantFP>(V)) {
- // FP -> Integral.
- if (DestTy == Type::Int32Ty) {
- APInt Val(32, 0);
- return ConstantInt::get(Val.floatToBits(FP->
- getValueAPF().convertToFloat()));
- } else {
- assert(DestTy == Type::Int64Ty && "only support f32/f64 for now!");
- APInt Val(64, 0);
- return ConstantInt::get(Val.doubleToBits(FP->
- getValueAPF().convertToDouble()));
- }
- }
- return 0;
+ return FoldBitCast(const_cast<Constant*>(V), DestTy);
default:
assert(!"Invalid CE CastInst opcode");
break;
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;
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:
- return 0;
+ // Undefined shuffle mask -> undefined value.
+ if (isa<UndefValue>(Mask)) return UndefValue::get(V1->getType());
+
+ unsigned NumElts = 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 != NumElts; ++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 >= NumElts*2)
+ InElt = UndefValue::get(EltTy);
+ else if (Elt >= NumElts)
+ InElt = GetVectorElement(V2, Elt-NumElts);
+ 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());
}
/// EvalVectorOp - Given two vector constants and a function pointer, apply the
/// function pointer to each element pair, producing a new ConstantVector
-/// constant.
+/// 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))));
+ 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:
}
}
- 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.
- 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->equalsInt(1))
- return const_cast<Constant*>(C1); // X * 1 == X
- break;
- case Instruction::UDiv:
- case Instruction::SDiv:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->equalsInt(1))
- return const_cast<Constant*>(C1); // X / 1 == X
- break;
- case Instruction::URem:
- case Instruction::SRem:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2))
- if (CI->equalsInt(1))
- return Constant::getNullValue(CI->getType()); // X % 1 == 0
- break;
- case Instruction::And:
- if (const ConstantInt *CI = dyn_cast<ConstantInt>(C2)) {
- if (CI->isZero()) return const_cast<Constant*>(C2); // X & 0 == 0
- if (CI->isAllOnesValue())
- return const_cast<Constant*>(C1); // X & -1 == X
-
- // (zext i32 to i64) & 4294967295 -> (zext i32 to i64)
- if (CE1->getOpcode() == Instruction::ZExt) {
- APInt PossiblySetBits
- = cast<IntegerType>(CE1->getOperand(0)->getType())->getMask();
- PossiblySetBits.zext(C1->getType()->getPrimitiveSizeInBits());
- if ((PossiblySetBits & CI->getValue()) == PossiblySetBits)
- return const_cast<Constant*>(C1);
- }
- }
- 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->getValue().ult(APInt(CI->getType()->getBitWidth(),4)) &&
- isa<Function>(CPR))
- return Constant::getNullValue(CI->getType());
- }
- break;
- 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;
- case Instruction::Xor:
- if (C2->isNullValue()) return const_cast<Constant*>(C1); // X ^ 0 == X
- break;
- case Instruction::AShr:
- // ashr (zext C to Ty), C2 -> lshr (zext C, CSA), C2
- if (CE1->getOpcode() == Instruction::ZExt) // Top bits known zero.
- return ConstantExpr::getLShr(const_cast<Constant*>(C1),
- const_cast<Constant*>(C2));
- break;
- }
- }
- } 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.
+ // Handle simplifications of the RHS when 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
+ break;
+ case Instruction::URem:
+ case Instruction::SRem:
+ if (CI2->equalsInt(1))
+ return Constant::getNullValue(CI2->getType()); // X % 1 == 0
+ 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:
- // No change of opcode required.
- return ConstantFoldBinaryInstruction(Opcode, C2, C1);
-
- case Instruction::Shl:
- case Instruction::LShr:
+ if (CI2->equalsInt(0)) return const_cast<Constant*>(C1); // X ^ 0 == X
+ break;
case Instruction::AShr:
- case Instruction::Sub:
- case Instruction::SDiv:
- case Instruction::UDiv:
- case Instruction::FDiv:
- case Instruction::URem:
- case Instruction::SRem:
- case Instruction::FRem:
- default: // These instructions cannot be flopped around.
- return 0;
+ // 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 nor a ConstantExpr
- // so look at directly computing the value.
+
+ // 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;
- APInt C1V = CI1->getValue();
- APInt C2V = CI2->getValue();
+ const APInt &C1V = CI1->getValue();
+ const APInt &C2V = CI2->getValue();
switch (Opcode) {
default:
break;
return ConstantInt::get(C1V | C2V);
case Instruction::Xor:
return ConstantInt::get(C1V ^ C2V);
- case Instruction::Shl:
- if (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
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
- case Instruction::LShr:
- if (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
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
- case Instruction::AShr:
- if (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
- return const_cast<ConstantInt*>(CI1); // Zero shift is identity
+ 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
+ }
}
}
} else if (const ConstantFP *CFP1 = dyn_cast<ConstantFP>(C1)) {
APFloat C1V = CFP1->getValueAPF();
APFloat C2V = CFP2->getValueAPF();
APFloat C3V = C1V; // copy for modification
- bool isDouble = CFP1->getType()==Type::DoubleTy;
switch (Opcode) {
default:
break;
case Instruction::Add:
(void)C3V.add(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(C3V);
case Instruction::Sub:
(void)C3V.subtract(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(C3V);
case Instruction::Mul:
(void)C3V.multiply(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(C3V);
case Instruction::FDiv:
- // FIXME better to look at the return code
- if (C2V.isZero())
- if (C1V.isZero())
- // IEEE 754, Section 7.1, #4
- return ConstantFP::get(CFP1->getType(), isDouble ?
- APFloat(std::numeric_limits<double>::quiet_NaN()) :
- APFloat(std::numeric_limits<float>::quiet_NaN()));
- else if (C2V.isNegZero() || C1V.isNegative())
- // IEEE 754, Section 7.2, negative infinity case
- return ConstantFP::get(CFP1->getType(), isDouble ?
- APFloat(-std::numeric_limits<double>::infinity()) :
- APFloat(-std::numeric_limits<float>::infinity()));
- else
- // IEEE 754, Section 7.2, positive infinity case
- return ConstantFP::get(CFP1->getType(), isDouble ?
- APFloat(std::numeric_limits<double>::infinity()) :
- APFloat(std::numeric_limits<float>::infinity()));
(void)C3V.divide(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(C3V);
case Instruction::FRem:
- if (C2V.isZero())
+ if (C2V.isZero()) {
// IEEE 754, Section 7.1, #5
- return ConstantFP::get(CFP1->getType(), isDouble ?
- APFloat(std::numeric_limits<double>::quiet_NaN()) :
- APFloat(std::numeric_limits<float>::quiet_NaN()));
+ if (CFP1->getType() == Type::DoubleTy)
+ return ConstantFP::get(APFloat(std::numeric_limits<double>::
+ quiet_NaN()));
+ if (CFP1->getType() == Type::FloatTy)
+ return ConstantFP::get(APFloat(std::numeric_limits<float>::
+ quiet_NaN()));
+ break;
+ }
(void)C3V.mod(C2V, APFloat::rmNearestTiesToEven);
- return ConstantFP::get(CFP1->getType(), C3V);
+ return ConstantFP::get(C3V);
}
}
- } else if (const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1)) {
- if (const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2)) {
+ } 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, 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);
+ default:
+ break;
+ case Instruction::Add:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getAdd);
+ case Instruction::Sub:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getSub);
+ case Instruction::Mul:
+ return EvalVectorOp(CP1, CP2, VTy, ConstantExpr::getMul);
+ 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);
}
}
}
- // We don't know how to fold this
+ 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::Mul:
+ 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::SDiv:
+ case Instruction::UDiv:
+ case Instruction::FDiv:
+ case Instruction::URem:
+ case Instruction::SRem:
+ case Instruction::FRem:
+ default: // These instructions cannot be flopped around.
+ break;
+ }
+ }
+
+ // 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;
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()->isInteger())) {
- 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);
+ 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 (CE2->isCast() && isa<PointerType>(CE1->getType()) &&
CE1->getOperand(0)->getType() == CE2->getOperand(0)->getType() &&
CE1->getOperand(0)->getType()->isInteger()) {
- bool sgnd = CE1->getOpcode() == Instruction::ZExt ? false :
- (CE1->getOpcode() == Instruction::SExt ? true :
- (CE1->getOpcode() == Instruction::PtrToInt ? false : isSigned));
+ 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;
}
}
if (isa<UndefValue>(C1) || isa<UndefValue>(C2))
return UndefValue::get(Type::Int1Ty);
+ // 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)) {
if (const ConstantVector *CP2 = dyn_cast<ConstantVector>(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)));
+ Constant *C = ConstantExpr::getFCmp(FCmpInst::FCMP_OEQ,
+ CP1->getOperand(i),
+ CP2->getOperand(i));
if (ConstantInt *CB = dyn_cast<ConstantInt>(C))
return CB;
}
} 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)));
+ CP1->getOperand(i),
+ CP2->getOperand(i));
if (ConstantInt *CB = dyn_cast<ConstantInt>(C))
return CB;
}
return const_cast<Constant*>(C);
if (isa<UndefValue>(C)) {
- const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(),
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
(Value **)Idxs,
(Value **)Idxs+NumIdx,
true);
assert(Ty != 0 && "Invalid indices for GEP!");
- return UndefValue::get(PointerType::get(Ty));
+ return UndefValue::get(PointerType::get(Ty, Ptr->getAddressSpace()));
}
Constant *Idx0 = Idxs[0];
break;
}
if (isNull) {
- const Type *Ty = GetElementPtrInst::getIndexedType(C->getType(),
+ const PointerType *Ptr = cast<PointerType>(C->getType());
+ const Type *Ty = GetElementPtrInst::getIndexedType(Ptr,
(Value**)Idxs,
(Value**)Idxs+NumIdx,
true);
assert(Ty != 0 && "Invalid indices for GEP!");
- return ConstantPointerNull::get(PointerType::get(Ty));
+ return
+ ConstantPointerNull::get(PointerType::get(Ty,Ptr->getAddressSpace()));
}
}
projects / oota-llvm.git / blobdiff