[PATCH] D93065: [InstCombine] Disable optimizations of select instructions that causes propagation of poison values

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

Current diff for flipping the flag: https://gist.github.com/nikic/f65b36adb70c93f5da9bfe3422fd8904 There's still a number of cases that can be handled.

I have a patch for supporting logical and/or in PredicateInfo, but waiting on D94447 <https://reviews.llvm.org/D94447> to land first.

I also noticed that SimplifyCFG is creating and/or when merging branch conditions in https://github.com/llvm/llvm-project/blob/ecf696641e6ce4b22e8c8ea3c7476b9c1f0f200b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp#L2959. I think it would make sense to switch that code over to use the select form first. That will make the transform correct in SimplifyCFG, but still let it be folded by InstCombine. As other passes have already been adjusted to recognize logical and/or, this should be low impact.


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  https://reviews.llvm.org/D93065/new/

https://reviews.llvm.org/D93065