[llvm] [AMDGPU] Set SGPR spill stack IDs when creating spill slots (PR #197628)

[Matt Arsenault via llvm-commits]

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@@ -1949,7 +1948,8 @@ void SIInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
       FrameInfo.getObjectAlign(FrameIndex));
 
   if (RI.isSGPRClass(RC)) {
-    MFI->setHasSpilledSGPRs();
+    if (FrameInfo.getStackID(FrameIndex) == TargetStackID::SGPRSpill)
+      MFI->setHasSpilledSGPRs();
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arsenm wrote:

I think this was used to detect if we will need to introduce CSR spills 

https://github.com/llvm/llvm-project/pull/197628