[PATCH] D49179: [InstCombine] Fold x & (-1 >> y) == x to x u<= (-1 >> y)

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri updated this revision to Diff 155015.
lebedev.ri marked 4 inline comments as done.
lebedev.ri added a comment.

Address @spatel's review notes.

In https://reviews.llvm.org/D49179#1158760, @spatel wrote:

> I'm not too worried about the missing fold in foldLogOpOfMaskedICmps(). That's a complex mess, so not surprising that it has logic holes. I've wondered if we could rewrite that using ranges to simplify that code.


That's, relieving to know!
I have looked a bit more, and i'm not sure what goes wrong,
so one regression can slip, that'd be great.


Repository:
  rL LLVM

https://reviews.llvm.org/D49179

Files:
  include/llvm/IR/PatternMatch.h
  lib/Transforms/InstCombine/InstCombineCompares.cpp
  test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-eq-to-icmp-ule.ll
  test/Transforms/InstCombine/canonicalize-low-bit-mask-and-icmp-eq-to-icmp-ule.ll
  test/Transforms/InstCombine/icmp-logical.ll
  test/Transforms/InstCombine/icmp-mul-zext.ll

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