[PATCH] D146823: [GVN] Avoid replacing uniforms with non-uniforms in propagateEquality

Mon Mar 27 08:42:18 PDT 2023

bogner added a comment.

In D146823#4223645 <https://reviews.llvm.org/D146823#4223645>, @sameerds wrote:

> In D146823#4219970 <https://reviews.llvm.org/D146823#4219970>, @bogner wrote:
>
>> A couple of things I'm not 100% sure about:
>>
>> - Are we okay with adding the TTI dependency on GVN? We already depend on TLI so I think it's probably okay.
>> - Is this testable at all without the AMDGPU backend? I don't think there's a way to imply uniformity generically
>
> In general divergence exists only on targets that have branch divergence, which is why this change matters on those targets such as AMDGPU. On a CPU target, everything is always uniform. So any test needs a GPU target.

Yep, that's all clear. I was thinking more along the lines of if there's some attribute or something that the base handles generically for testing purposes. If there's nothing like that today that's fine.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D146823/new/

https://reviews.llvm.org/D146823