[PATCH] D59535: [SelectionDAG] Compute known bits of CopyFromReg

[Piotr Sobczak via Phabricator via llvm-commits]

piotr added a comment.

Yes, we see improvements on the AMDGPU target.

> I think it may be more accurate to say that this breaks a whole class of existing optimisations.

We need a test for each of these cases. Otherwise we risk having the same problem all over again.

@dmgreen Please revert the patch and add new tests in a separate review. I would prefer if you added the new tests first, but it is not essential.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59535/new/

https://reviews.llvm.org/D59535