[PATCH] D56289: Added single use check to ShrinkDemandedConstant

[Florian Hahn via Phabricator via llvm-commits]

fhahn added a comment.

I am seeing a regression with this change on AArch64, where we do not use shrinked constants, e.g. for and/or if they have multiple users. I am not entirely sure what the problem is this patch is solving, as I am not familiar with AMDGPU. Is it a case where shrinking the constant leads to shrinking the related `Op` and in the end this introduces unnecessary conversion code, as multiple users require different bitwidths?

If that is the case, I am not sure if this is the best place to fix the issue. IIUC, shrinkDemandedBits just shrinks the constant of the passed in `Op`, but not the width of the result type of `Op`. So it seems to me that shrinking the constant should be independent of the users of `Op`.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D56289/new/

https://reviews.llvm.org/D56289