craig.topper added inline comments.
================
Comment at: clang/lib/AST/ExprConstant.cpp:2915
case BO_EQ:
- Result = (LHSValue == RHSValue);
+ Result = -(LHSValue == RHSValue);
break;
----------------
erichkeane wrote:
> efriedma wrote:
> > Using "operator=" to assign an int to an APInt is going to lead to
> > weird/confusing results. For example, I think this produces the wrong
> > result if you have an int128_t vector.
> Can you clarify your comment? The result type of one of these compare-ops is
> either an i8 or an i32 I think, so I would expect it to 'just work', right?
>
> What problem of operator= on an APInt gives the wrong result? I guess I've
> never seen/don't know how to repro what you mean.
>
> I DID try to get a test wtih a 'compare op' on an __int128 vector, but that
> ends up asserting in GetSignedVectorType
Don't compare ops produce a result with the same number of bits as the input?
If the compare is a vector of int128 the result should also be a vector of
int128. APInt::operator= takes a uint64_t as input and will zero extend it to
128 bits. I think we want to sign extend here.
I assume the APInt for result already been given its bit width before this call?
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D115670/new/
https://reviews.llvm.org/D115670
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