[PATCH] D85592: [Attributor] Add flag for undef value to the state of AAPotentialValues

[Florian Hahn via Phabricator via llvm-commits]

fhahn added a comment.

I am not sure if the following scenario is possible, but if it is it might be problematic when undef is unified with multiple values. E.g. we found that we have the following potential values `0, 1, undef`. If we now assume this is `0, 1`, we might simplify `and %x, 3` to `%x`. But that is wrong, if `%x` is `undef`. Note that simplifications that result in a constant should be fine either way. As I said, not sure if the potential values could be used like that (possibly in the future).


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https://reviews.llvm.org/D85592