[AMDGPU] Fix back off barrier checks

Author: jayfoad

llvm/test/CodeGen/AMDGPU/back-off-barrier-subtarget-feature.ll

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck --check-prefixes=GFX9-NO-BACKOFF %s
 ; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx90a -verify-machineinstrs < %s | FileCheck --check-prefixes=GFX9-BACKOFF %s
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx940 -verify-machineinstrs < %s | FileCheck --check-prefixes=GFX9-BACKOFF %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx940 -verify-machineinstrs < %s | FileCheck --check-prefixes=GFX940-BACKOFF %s
 ; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx90a -mattr=-back-off-barrier -verify-machineinstrs < %s | FileCheck --check-prefixes=GFX9-NO-BACKOFF %s
 ; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1010 -verify-machineinstrs < %s | FileCheck --check-prefixes=GFX10-BACKOFF %s
 ; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1100 -verify-machineinstrs < %s | FileCheck --check-prefixes=GFX11-BACKOFF %s
@@ -30,6 +30,16 @@ define void @back_off_barrier_no_fence(ptr %in, ptr %out) #0 {
 ; GFX9-BACKOFF-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
 ; GFX9-BACKOFF-NEXT:    s_setpc_b64 s[30:31]
 ;
+; GFX940-BACKOFF-LABEL: back_off_barrier_no_fence:
+; GFX940-BACKOFF:       ; %bb.0:
+; GFX940-BACKOFF-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX940-BACKOFF-NEXT:    flat_load_dword v0, v[0:1]
+; GFX940-BACKOFF-NEXT:    s_barrier
+; GFX940-BACKOFF-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
+; GFX940-BACKOFF-NEXT:    flat_store_dword v[2:3], v0 sc0 sc1
+; GFX940-BACKOFF-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
+; GFX940-BACKOFF-NEXT:    s_setpc_b64 s[30:31]
+;
 ; GFX10-BACKOFF-LABEL: back_off_barrier_no_fence:
 ; GFX10-BACKOFF:       ; %bb.0:
 ; GFX10-BACKOFF-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
@@ -78,6 +88,17 @@ define void @back_off_barrier_with_fence(ptr %in, ptr %out) #0 {
 ; GFX9-BACKOFF-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
 ; GFX9-BACKOFF-NEXT:    s_setpc_b64 s[30:31]
 ;
+; GFX940-BACKOFF-LABEL: back_off_barrier_with_fence:
+; GFX940-BACKOFF:       ; %bb.0:
+; GFX940-BACKOFF-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX940-BACKOFF-NEXT:    flat_load_dword v0, v[0:1]
+; GFX940-BACKOFF-NEXT:    s_waitcnt lgkmcnt(0)
+; GFX940-BACKOFF-NEXT:    s_barrier
+; GFX940-BACKOFF-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
+; GFX940-BACKOFF-NEXT:    flat_store_dword v[2:3], v0 sc0 sc1
+; GFX940-BACKOFF-NEXT:    s_waitcnt vmcnt(0) lgkmcnt(0)
+; GFX940-BACKOFF-NEXT:    s_setpc_b64 s[30:31]
+;
 ; GFX10-BACKOFF-LABEL: back_off_barrier_with_fence:
 ; GFX10-BACKOFF:       ; %bb.0:
 ; GFX10-BACKOFF-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)