[PATCH] D122607: AMDGPU: Delete spills of undef values

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/test/CodeGen/AMDGPU/sgpr-spill-partially-undef.mir:69
+    ; CHECK-LABEL: name: sgpr_spill_s32_undef
+    ; CHECK: liveins: $vgpr0
+    ; CHECK-NEXT: {{  $}}
----------------
scott.linder wrote:
> Is there any downside to the VGPR remaining livein, even if no spill to it survives? I can't tell if the VGPR remains reserved in this case, but if not could the liveness end up incorrect?
Not really. We both add the VGPRs selected for SGPR spills to live ins and redundantly add them to reserved registers. We should also probably work on spilling to virtual VGPRs now that the passes are split


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122607/new/

https://reviews.llvm.org/D122607