[PATCH] D86430: [SelectionDAG] Fix miscompile bug in expandFunnelShift

[Jay Foad via Phabricator via llvm-commits]

foad added a comment.

> It could be possible to add back the transform, given that logic
> is added to check that (Z % BW) can't be zero. Since there were
> no test cases proving that such a transform actually would be useful
> I decided to simply remove the faulty code in this patch.

I don't understand this. The AMDGPU test changes clearly show that the transform is useful. AMDGPU has an alignbit instruction which is fshr, but no instruction for fshl.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86430/new/

https://reviews.llvm.org/D86430