//
// 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 = cast<ConstantFP>(CV->getOperand(i))->
- getValueAPF().convertToAPInt().getZExtValue();
- 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 = (uint32_t)cast<ConstantFP>(CV->getOperand(i))->
- getValueAPF().convertToAPInt().getZExtValue();
- 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)) {
+ 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(DestTy, 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);
}
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
APInt api = CI->getValue();
const uint64_t zero[] = {0, 0};
- uint32_t BitWidth = cast<IntegerType>(SrcTy)->getBitWidth();
APFloat apf = APFloat(APInt(DestTy->getPrimitiveSizeInBits(),
2, zero));
- (void)apf.convertFromZeroExtendedInteger(api.getRawData(), BitWidth,
- opc==Instruction::SIToFP,
- APFloat::rmNearestTiesToEven);
+ (void)apf.convertFromAPInt(api,
+ opc==Instruction::SIToFP,
+ APFloat::rmNearestTiesToEven);
return ConstantFP::get(DestTy, apf);
}
if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
}
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()) {
- assert((DestTy == Type::DoubleTy || DestTy == Type::FloatTy) &&
- "Unknown FP type!");
- return ConstantFP::get(DestTy, 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;
+ return FoldBitCast(const_cast<Constant*>(V), DestTy);
default:
assert(!"Invalid CE CastInst opcode");
break;
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 const_cast<Constant*>(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
case Instruction::Xor:
return ConstantInt::get(C1V ^ C2V);
case Instruction::Shl:
- if (uint32_t shiftAmt = C2V.getZExtValue())
+ 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 (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 (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::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 (C1->isNullValue()) {
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C2))
// Don't try to evaluate aliases. External weak GV can be null.
- if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage())
+ 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))
// Don't try to evaluate aliases. External weak GV can be null.
- if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage())
+ 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)) {
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()));
}
}