[PATCH] D108830: [AMDGPU] Propagate defining src reg for AGPR to AGPR Copys

Wed Nov 3 02:07:27 PDT 2021

foad added inline comments.

================
Comment at: llvm/lib/Target/AMDGPU/GCNPreRAOptimizations.cpp:104
+      if (!IsAGPRDst)
+        break;
+
----------------
vangthao wrote:
> foad wrote:
> > piotr wrote:
> > > I'm seeing issues with this commit on targets without agpr (e.g. gfx900).
> > > I think there is a change in behaviour here - previously on COPY there was an early return. Now, there is only a switch break, so the loop continues. Is this intended?
> > @vangthao ping! This is causing codegen differences on gfx900 which has no AGPRs. Can you please comment on whether that is expected, and if so why? Thanks!
> Sorry I missed this comment.
> 
> This behavior is not intended. The issue was found and should be fixed in https://reviews.llvm.org/D113005
Thanks. We are testing that fix now.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D108830/new/

https://reviews.llvm.org/D108830