[PATCH] D62818: [InstCombine] Allow ((X << Y) & SignMask) != 0 to be optimized as (X << Y) s< 0.

[Huihui Zhang via Phabricator via llvm-commits]

huihuiz added a comment.

The other approach could be changing the order of folding. Move foldICmpBinOpEqualityWithConstant to the very beginning of foldICmpInstWithConstant. 
foldICmpBinOpEqualityWithConstant has rules to replace (and X, (1 << size(X)-1) != 0) with x s< 0.
Let me know if this approach is more preferable?


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  rL LLVM

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  https://reviews.llvm.org/D62818/new/

https://reviews.llvm.org/D62818