[llvm] AMDGPU: Fold copy of scalar add of frame index (PR #115058)

[Matt Arsenault via llvm-commits]

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@@ -78,6 +78,12 @@ class SIFoldOperandsImpl {
   bool frameIndexMayFold(const MachineInstr &UseMI, int OpNo,
                          const MachineOperand &OpToFold) const;
 
+  /// Fold %vgpr = COPY (S_ADD_I32 x, frameindex)
+  ///
+  ///   => %vgpr = V_ADD_U32 x, frameindex
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arsenm wrote:

Frame index is treated as if it were a VGPR since a few months ago, so we don't need to care what the other operand is 

https://github.com/llvm/llvm-project/pull/115058