//
// 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.
//
//===----------------------------------------------------------------------===//
//
Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
const Type *DestTy) {
- const Type *SrcTy = V->getType();
-
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;
}
+/// 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
}
}
// 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()));
}
}
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