[PATCH] D145341: [InstCombine] Add transform `(icmp pred (shl {nsw and/or nuw} X, Y), C)` -> `(icmp pred X, C)`

[Nikita Popov via Phabricator via llvm-commits]

nikic accepted this revision.
nikic added a comment.
This revision is now accepted and ready to land.

LGTM



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Comment at: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp:2191-2195
     // If this is a signed comparison to 0 and the shift is sign preserving,
     // use the shift LHS operand instead; isSignTest may change 'Pred', so only
     // do that if we're sure to not continue on in this function.
     if (isSignTest(Pred, C))
       return new ICmpInst(Pred, X, Constant::getNullValue(ShType));
----------------
Can we drop this fold now?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D145341/new/

https://reviews.llvm.org/D145341