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Fix a case where vector comparison constant folding would cause an 

infinite recursion.  part of PR2529

llvm-svn: 53383
This commit is contained in:
Chris Lattner 2008-07-10 00:29:28 +00:00
parent 97c661df7a
commit 67136cff7b
2 changed files with 39 additions and 33 deletions
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30
llvm/lib/VMCore/ConstantFold.cpp
View File

@ -1348,43 +1348,43 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
return ConstantInt::get(Type::Int1Ty, R==APFloat::cmpGreaterThan ||
R==APFloat::cmpEqual);
}
} else if (const ConstantVector *CP1 = dyn_cast<ConstantVector>(C1)) {
if (const ConstantVector *CP2 = dyn_cast<ConstantVector>(C2)) {
} 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> Elts;
const Type *InEltTy = CP1->getOperand(0)->getType();
SmallVector<Constant*, 4> ResElts;
const Type *InEltTy = C1Elts[0]->getType();
bool isFP = InEltTy->isFloatingPoint();
const Type *ResEltTy = InEltTy;
if (isFP)
ResEltTy = IntegerType::get(InEltTy->getPrimitiveSizeInBits());
for (unsigned i = 0, e = CP1->getNumOperands(); i != e; ++i) {
for (unsigned i = 0, e = C1Elts.size(); i != e; ++i) {
// Compare the elements, producing an i1 result or constant expr.
Constant *C;
if (isFP)
C = ConstantExpr::getFCmp(pred, CP1->getOperand(i),
CP2->getOperand(i));
C = ConstantExpr::getFCmp(pred, C1Elts[i], C2Elts[i]);
else
C = ConstantExpr::getICmp(pred, CP1->getOperand(i),
CP2->getOperand(i));
C = ConstantExpr::getICmp(pred, C1Elts[i], C2Elts[i]);
// If it is a bool or undef result, convert to the dest type.
if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
if (CI->isZero())
Elts.push_back(Constant::getNullValue(ResEltTy));
ResElts.push_back(Constant::getNullValue(ResEltTy));
else
Elts.push_back(Constant::getAllOnesValue(ResEltTy));
ResElts.push_back(Constant::getAllOnesValue(ResEltTy));
} else if (isa<UndefValue>(C)) {
Elts.push_back(UndefValue::get(ResEltTy));
ResElts.push_back(UndefValue::get(ResEltTy));
} else {
break;
}
}
if (Elts.size() == CP1->getNumOperands())
return ConstantVector::get(&Elts[0], Elts.size());
}
if (ResElts.size() == C1Elts.size())
return ConstantVector::get(&ResElts[0], ResElts.size());
}
if (C1->getType()->isFloatingPoint()) {

6
llvm/test/Transforms/ConstProp/2008-07-07-VectorCompare.ll
View File

@ -20,3 +20,9 @@ undef>, <float 1.0, float 1.0, float 1.0, float undef>
ret <4 x i32> %foo
}
define <4 x i32> @test4() {
%foo = vfcmp ueq <4 x float> <float 0.0, float 0.0, float 0.0, float 0.0>, <float 1.0, float 1.0, float 1.0, float 0.0>
ret <4 x i32> %foo
}