[llvm] [AMDGPU] Add a trap lowering workaround for gfx11 (PR #85854)

[Matt Arsenault via llvm-commits]

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@@ -197,6 +250,21 @@ define amdgpu_kernel void @debugtrap(ptr addrspace(1) nocapture readonly %arg0)
 ; HSA-NOTRAP-GFX900-NEXT:    global_store_dword v0, v2, s[0:1]
 ; HSA-NOTRAP-GFX900-NEXT:    s_waitcnt vmcnt(0)
 ; HSA-NOTRAP-GFX900-NEXT:    s_endpgm
+;
+; HSA-TRAP-GFX1100-LABEL: debugtrap:
+; HSA-TRAP-GFX1100:       ; %bb.0:
+; HSA-TRAP-GFX1100-NEXT:    s_load_b64 s[0:1], s[0:1], 0x0
+; HSA-TRAP-GFX1100-NEXT:    v_dual_mov_b32 v0, 0 :: v_dual_mov_b32 v1, 1
+; HSA-TRAP-GFX1100-NEXT:    v_mov_b32_e32 v2, 2
+; HSA-TRAP-GFX1100-NEXT:    s_waitcnt lgkmcnt(0)
+; HSA-TRAP-GFX1100-NEXT:    global_store_b32 v0, v1, s[0:1] dlc
+; HSA-TRAP-GFX1100-NEXT:    s_waitcnt_vscnt null, 0x0
+; HSA-TRAP-GFX1100-NEXT:    s_trap 3
+; HSA-TRAP-GFX1100-NEXT:    global_store_b32 v0, v2, s[0:1] dlc
+; HSA-TRAP-GFX1100-NEXT:    s_waitcnt_vscnt null, 0x0
+; HSA-TRAP-GFX1100-NEXT:    s_nop 0
+; HSA-TRAP-GFX1100-NEXT:    s_sendmsg sendmsg(MSG_DEALLOC_VGPRS)
+; HSA-TRAP-GFX1100-NEXT:    s_endpgm
   store volatile i32 1, ptr addrspace(1) %arg0
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arsenm wrote:

Should have a -O0 test. Is this emulation safe in the presence of any spills? 

https://github.com/llvm/llvm-project/pull/85854