[PATCH] D137705: [AMDGPU] Add DAG Combine for right-shift carry add to uaddo

Thu Nov 17 15:49:11 PST 2022

arsenm added a comment.

In D137705#3933081 <https://reviews.llvm.org/D137705#3933081>, @Pierre-vh wrote:

> In D137705#3932390 <https://reviews.llvm.org/D137705#3932390>, @arsenm wrote:
>
>> Apparently there is already an in flight version of this at D106139 <https://reviews.llvm.org/D106139>
>
> Right, I think the reviewers there asked to move it to InstCombine, but I think we also want it in the backend, right?

Combines in the backend are primarily for patterns that arise as the result of legalization. Looking at this again, I'm inclined to have it in instcombine primarily.

> Perhaps it should be kept as a target-specific combine for now? It can always be moved later if needed

It definitely should be done generically

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137705/new/

https://reviews.llvm.org/D137705