[PATCH] D96336: [AMDGPU] Save VGPR of whole wave when spilling

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h:494-495
 
+  /// When spilling SGPRs, we may need a temporary stack slot to free a VGPR.
+  Optional<int> SpillSGPRTmpIndex;
+
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sebastian-ne wrote:
> arsenm wrote:
> > Why doesn't this use the normal emergency stack slot?
> How do I get the emergency stack slot?
You don't get it, it just is what automatically happens when you attempt to use the scavenger and it fails to find a free register. It's possible we would need to add SGPR  spills as one of the conditions where it will be necessary


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  https://reviews.llvm.org/D96336/new/

https://reviews.llvm.org/D96336