[PATCH] D101489: [InstCombine] improve demanded bits analysis of left-shifted operand

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

For reference, this patch missed a requirement: we have to drop poison flags on the `shl` as part of the transform.
Otherwise, we can miscompile as shown in:
https://llvm.org/PR50341
Should be fixed with:
e82db87fb102 <https://reviews.llvm.org/rGe82db87fb102f01b0895b074e56568025c659575>


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D101489/new/

https://reviews.llvm.org/D101489