[llvm] [AMDGCN] Allow unscheduling of bundled insns (PR #129769)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,28 @@
+; REQUIRES: asserts
+; RUN: llc -mtriple=amdgcn -O1 -mcpu=gfx90a -debug-only=machine-scheduler -stop-after=machine-scheduler < %s 2>%t | FileCheck %s
+; RUN: FileCheck --check-prefix=DEBUG %s < %t
+
+; DEBUG: Attempting to revert scheduling.
+
+; CHECK:      BUNDLE implicit $m0, implicit $exec {
+; CHECK-NEXT:   DS_GWS_SEMA_V 0, implicit $m0, implicit $exec :: (store (s32) into custom "GWSResource")
+; CHECK-NEXT:   S_WAITCNT 0
+; CHECK-NEXT: }
+
+ at G = global <32 x i8> splat (i8 1)
+ at G.1 = global <32 x i8> splat (i8 127)
+
+define amdgpu_kernel void @gws_sema_v_offset0(i32 %val) #0 {
+  %LGV1 = load <32 x i8>, ptr @G.1, align 32
+  %LGV = load <32 x i8>, ptr @G, align 32
+  call void @llvm.amdgcn.ds.gws.sema.v(i32 0)
+  %C = icmp ne <32 x i8> %LGV, %LGV1
+  store <32 x i1> %C, ptr poison, align 4
+  ret void
+}
+
+declare void @llvm.amdgcn.ds.gws.sema.v(i32) #1
+
+attributes #0 = { convergent nounwind memory(inaccessiblemem: readwrite) }
+attributes #1 = { convergent nocallback nofree nounwind willreturn memory(inaccessiblemem: readwrite) }
+
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arsenm wrote:

```suggestion
```

https://github.com/llvm/llvm-project/pull/129769