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Fix BasicAA/2006-11-03-BasicAAVectorCrash.ll by handling out-of-range 

vector accesses like we handle out-of-range array accesses.

llvm-svn: 31427
This commit is contained in:
Chris Lattner 2006-11-03 21:58:48 +00:00
parent 67af941db1
commit ea2abe2384
1 changed files with 20 additions and 8 deletions
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28
llvm/lib/Analysis/BasicAliasAnalysis.cpp
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@ -555,20 +555,21 @@ BasicAliasAnalysis::CheckGEPInstructions(
}
if (G1OC != G2OC) {
// Handle the "be careful" case above: if this is an array
// Handle the "be careful" case above: if this is an array/packed
// subscript, scan for a subsequent variable array index.
if (isa<ArrayType>(BasePtr1Ty)) {
const Type *NextTy =cast<ArrayType>(BasePtr1Ty)->getElementType();
if (isa<SequentialType>(BasePtr1Ty)) {
const Type *NextTy =
cast<SequentialType>(BasePtr1Ty)->getElementType();
bool isBadCase = false;
for (unsigned Idx = FirstConstantOper+1;
Idx != MinOperands && isa<ArrayType>(NextTy); ++Idx) {
Idx != MinOperands && isa<SequentialType>(NextTy); ++Idx) {
const Value *V1 = GEP1Ops[Idx], *V2 = GEP2Ops[Idx];
if (!isa<Constant>(V1) || !isa<Constant>(V2)) {
isBadCase = true;
break;
}
NextTy = cast<ArrayType>(NextTy)->getElementType();
NextTy = cast<SequentialType>(NextTy)->getElementType();
}
if (isBadCase) G1OC = 0;
@ -668,10 +669,14 @@ BasicAliasAnalysis::CheckGEPInstructions(
if (Op1) {
if (const ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
// If this is an array index, make sure the array element is in range.
if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty)) {
if (Op1C->getZExtValue() >= AT->getNumElements())
return MayAlias; // Be conservative with out-of-range accesses
} else if (const PackedType *PT = dyn_cast<PackedType>(BasePtr1Ty)) {
if (Op1C->getZExtValue() >= PT->getNumElements())
return MayAlias; // Be conservative with out-of-range accesses
}
} else {
// GEP1 is known to produce a value less than GEP2. To be
// conservatively correct, we must assume the largest possible
@ -685,15 +690,22 @@ BasicAliasAnalysis::CheckGEPInstructions(
//
if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
GEP1Ops[i] = ConstantInt::get(Type::LongTy, AT->getNumElements()-1);
else if (const PackedType *PT = dyn_cast<PackedType>(BasePtr1Ty))
GEP1Ops[i] = ConstantInt::get(Type::LongTy, PT->getNumElements()-1);
}
}
if (Op2) {
if (const ConstantInt *Op2C = dyn_cast<ConstantInt>(Op2)) {
// If this is an array index, make sure the array element is in range.
if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty)) {
if (Op2C->getZExtValue() >= AT->getNumElements())
return MayAlias; // Be conservative with out-of-range accesses
} else if (const PackedType *PT = dyn_cast<PackedType>(BasePtr1Ty)) {
if (Op2C->getZExtValue() >= PT->getNumElements())
return MayAlias; // Be conservative with out-of-range accesses
}
} else { // Conservatively assume the minimum value for this index
GEP2Ops[i] = Constant::getNullValue(Op2->getType());
}