[PATCH] D71799: [Attributor] AAUndefinedBehavior: Check for branches on undef value.

[Stefanos Baziotis via Phabricator via llvm-commits]

baziotis added a comment.

>   SimplifiedV = ...;
>   if (!SimplifiedV.hasValue())
>     ... // Do nothing for now, no value yet.
>   else {
>     Val = SimplifiedV.getValue();
>     if (Val is undef)
>       UBInsts.insert;
>     else
>       NoUBInsts.insert;
>   }

Note that while this is what makes sense to me, Johannes told me that if `SimplifiedV` gives `None` (i.e. it doesn't have value), then we can assume
that it is `undef` but I don't know why this is true.

Edit: Just saw your comment, which you seem to not assume that.
In your code, why insert it in `UBInsts` and then remove it? Since we query `AAValueSimplify`, isn't that going to call us again and thus at some point get the value (which in turn means we don't insert it and just wait for when we'll be called again).


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  https://reviews.llvm.org/D71799/new/

https://reviews.llvm.org/D71799