[PATCH] D49384: [IPSCCP] Do not zap return if the return value is overdefined at any call site.

[Florian Hahn via Phabricator via llvm-commits]

fhahn added a comment.

In https://reviews.llvm.org/D49384#1164252, @efriedma wrote:

> Stuff like this really makes me want to kill off ResolveUndefsIn.  But this works for now.


Yeah I guess if we continue to make SCCP more powerful, we hit more cases like this. For example, the problem was exposed by https://reviews.llvm.org/rL336098. I am not sure what a good alternative to ResolvedUndefsIn() would be. Just marking undef conditions as overdefined after a round of Solve()? I am not sure how big the ResolvedUndefsIn contributes to the overall precision.


https://reviews.llvm.org/D49384