[PATCH] D77868: [InstSimplify] fold select of bools using bitwise logic

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In D77868#1974228 <https://reviews.llvm.org/D77868#1974228>, @nikic wrote:

> What is the motivation for having this fold partially (only if recursively simplifiable) in InstSimplify, rather than doing the full fold in InstCombine?


If the logic can be simplified, then that makes it poison-safe. Ie, if the logic op simplifies, that means the logic op must be filtering out a poisoned value the same as we would expect of a select. Does that make sense, or do you know of a counter-example?
But not sure if that's the question: handle all 4 of the logic-op possibilities (and-not/or-not) rather than just and/or in instcombine rather than here?


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