When transforming &A[i] < &A[j] -> i < j, make sure to perform the comparison

as a signed compare.  This patch may fix PR597, but is correct in any case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22465 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-07-18 23:07:33 +00:00
parent f4d32726e6
commit 7911f03626

View File

@ -2367,10 +2367,17 @@ Instruction *InstCombiner::FoldGEPSetCC(User *GEPLHS, Value *RHS,
else if (NumDifferences == 1) {
Value *LHSV = GEPLHS->getOperand(DiffOperand);
Value *RHSV = GEPRHS->getOperand(DiffOperand);
if (LHSV->getType() != RHSV->getType())
LHSV = InsertNewInstBefore(new CastInst(LHSV, RHSV->getType(),
LHSV->getName()+".c"), I);
return new SetCondInst(Cond, LHSV, RHSV);
// Convert the operands to signed values to make sure to perform a
// signed comparison.
const Type *NewTy = LHSV->getType()->getSignedVersion();
if (LHSV->getType() != NewTy)
LHSV = InsertNewInstBefore(new CastInst(LHSV, NewTy,
LHSV->getName()), I);
if (RHSV->getType() != NewTy)
RHSV = InsertNewInstBefore(new CastInst(RHSV, NewTy,
RHSV->getName()), I);
return new SetCondInst(Cond, LHSV, RHSV);
}
}