Fix several bugs in basic-aa

llvm-svn: 5643
This commit is contained in:
Chris Lattner 2003-02-26 21:28:49 +00:00
parent ea424f3aff
commit e923b037b7

View File

@ -142,8 +142,10 @@ BasicAliasAnalysis::alias(const Value *V1, unsigned V1Size,
std::swap(V1Size, V2Size);
}
if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V1))
if (GEP->getOperand(0) == V2) {
if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V1)) {
AliasResult R = alias(GEP->getOperand(0), V1Size, V2, V2Size);
if (R == NoAlias) return NoAlias;
if (R == MustAlias) {
// If there is at least one non-zero constant index, we know they cannot
// alias.
for (unsigned i = 1, e = GEP->getNumOperands(); i != e; ++i)
@ -151,6 +153,7 @@ BasicAliasAnalysis::alias(const Value *V1, unsigned V1Size,
if (!C->isNullValue())
return NoAlias;
}
}
return MayAlias;
}
@ -220,8 +223,10 @@ BasicAliasAnalysis::CheckGEPInstructions(GetElementPtrInst *GEP1, unsigned G1S,
std::vector<Value*> Indices1;
Indices1.reserve(NumGEPOperands-1);
for (unsigned i = 1; i != FirstConstantOper; ++i)
Indices1.push_back(Constant::getNullValue(GEP1->getOperand(i)
->getType()));
if (GEP1->getOperand(i)->getType() == Type::UByteTy)
Indices1.push_back(GEP1->getOperand(i));
else
Indices1.push_back(Constant::getNullValue(Type::LongTy));
std::vector<Value*> Indices2;
Indices2.reserve(NumGEPOperands-1);
Indices2 = Indices1; // Copy the zeros prefix...
@ -235,7 +240,7 @@ BasicAliasAnalysis::CheckGEPInstructions(GetElementPtrInst *GEP1, unsigned G1S,
// Loop over the rest of the operands...
for (unsigned i = FirstConstantOper+1; i!=NumGEPOperands; ++i){
const Value *Op1 = GEP1->getOperand(i);
const Value *Op2 = GEP1->getOperand(i);
const Value *Op2 = GEP2->getOperand(i);
if (Op1 == Op2) { // If they are equal, use a zero index...
Indices1.push_back(Constant::getNullValue(Op1->getType()));
Indices2.push_back(Indices1.back());