[PATCH] D91725: [LoopIdiom] 'left-shift until bittest' idiom: support constant bit mask

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri created this revision.
lebedev.ri added reviewers: craig.topper, fhahn, jdoerfert.
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The handing of the case where the mask is a constant is trivial,
if said constant is a power of two, the bit in question is log2(mask),
rest just works.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D91725

Files:
  llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
  llvm/test/Transforms/LoopIdiom/X86/left-shift-until-bittest.ll

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