[PATCH] D68239: [InstCombine] dropRedundantMaskingOfLeftShiftInput(): change how we deal with mask

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

I'd be okay with either spliting this up further if wanted, or moving this particular patch
into post-commit review mode; the only worrying thing to me here is the `sanitizeUndefsTo()` itself.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68239/new/

https://reviews.llvm.org/D68239