[PATCH] D132888: [InstCombine] reduce test-for-overflow of shifted value

[Tian Zhou via Phabricator via llvm-commits]

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Refer to issue #57338 <https://github.com/llvm/llvm-project/issues/57338>. The added code makes the following transformations:
For unsigned predicates / eq / ne:

  icmp pred (x << 1), x --> icmp getSignedPredicate(pred) x, 0
  icmp pred x, (x << 1) --> icmp getSignedPredicate(pred) 0, x


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D132888

Files:
  llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
  llvm/test/Transforms/InstCombine/icmp-shl-1-overflow.ll

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