[llvm] [AMDGPU] New intrinsic llvm.amdgcn.pops.exiting.wave.id (PR #89612)

[Matt Arsenault via llvm-commits]

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@@ -213,6 +213,11 @@ let isMoveImm = 1 in {
   } // End Uses = [SCC]
 } // End isMoveImm = 1
 
+// Variant of S_MOV_B32 used for reading volatile source values like
+// SRC_POPS_EXITING_WAVE_ID.
+let mayLoad = 1, mayStore = 1, maybeAtomic = 0 in
+def S_MOV_B32_loadstore : SOP1_32 <"s_mov_b32">;
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arsenm wrote:

I'd rather avoid the pseudo. I'd probably prefer to just manually select over having it. But really that flag inference stuff in TableGen is garbage. We at minimum need to fix the properties to exactly match the attributes 

https://github.com/llvm/llvm-project/pull/89612