[llvm] [AMDGPU] Change SGPR layout to striped caller/callee saved (PR #127353)

[Shilei Tian via llvm-commits]

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@@ -91,7 +91,11 @@ def CSR_AMDGPU_AGPRs : CalleeSavedRegs<
 >;
 
 def CSR_AMDGPU_SGPRs : CalleeSavedRegs<
-  (sequence "SGPR%u", 30, 105)
+  (add (sequence "SGPR%u", 30, 37),
+       (sequence "SGPR%u", 46, 53),
+       (sequence "SGPR%u", 62, 69),
+       (sequence "SGPR%u", 78, 85),
+       (sequence "SGPR%u", 94, 105))
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shiltian wrote:

> We should be moving the special inputs to all be in callee saved sgprs.

This will be the goal of the next step, which is to revisit the SGPR layout and design a new one. It will be more intrusive and take fairly more time for discussion and tuning.

https://github.com/llvm/llvm-project/pull/127353