[PATCH] D122942: [InstCombine] Fold srem(X, PowerOf2) == C into (X & Mask) == C for positive C

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

In D122942#3423666 <https://reviews.llvm.org/D122942#3423666>, @lebedev.ri wrote:

> Please do post the proofs too.
>
> Is there some other precondition missing?
> https://alive2.llvm.org/ce/z/C8EscG

I believe the mask also needs to have the sign bit set. https://alive2.llvm.org/ce/z/eQGxvH


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