[PATCH] D85593: [InstCombine] ~(~X + Y) -> X - Y

[Sanjay Patel via Phabricator via llvm-commits]

spatel added subscribers: efriedma, regehr, nlopes.
spatel added a comment.

I agree that this looks wrong for the example with undef substituted in...but that also means that almost every instcombine that doesn't specify hasOneUse() is wrong!
But then how are we not miscompiling more often? We must be simplifying instructions with undefs before they can escape and cause trouble as @nikic hinted at?
@efriedma @regehr @nlopes - comments?


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https://reviews.llvm.org/D85593