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AMDGPU: Fix introducing use of killed vgpr in gfx908 agpr copy #149291

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Merged
merged 1 commit into from
Jul 18, 2025
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AMDGPU: Fix introducing use of killed vgpr in gfx908 agpr copy #149291

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3 changes: 2 additions & 1 deletion llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -687,7 +687,8 @@ static void indirectCopyToAGPR(const SIInstrInfo &TII,
if (!SafeToPropagate)
break;

DefOp.setIsKill(false);
for (auto I = Def; I != MI; ++I)
I->clearRegisterKills(DefOp.getReg(), &RI);
}

MachineInstrBuilder Builder =
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83 changes: 83 additions & 0 deletions llvm/test/CodeGen/AMDGPU/accvgpr-copy.mir
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,9 @@
define amdgpu_kernel void @copy_agpr_to_agpr_tuple() #0 { ret void }
define amdgpu_kernel void @copy_agpr_to_agpr_tuple_kill() #0 { ret void }

define amdgpu_kernel void @look_for_vgpr_killed() #0 { ret void }
define amdgpu_kernel void @look_for_vgpr_killed_tuple() #0 { ret void }

attributes #0 = { "amdgpu-flat-work-group-size"="1,256" }
...

Expand Down Expand Up @@ -1517,3 +1520,83 @@ body: |
renamable $agpr4_agpr5_agpr6_agpr7 = COPY renamable killed $agpr0_agpr1_agpr2_agpr3, implicit $exec
S_ENDPGM 0, implicit $agpr4_agpr5_agpr6_agpr7
...

# Make sure the expansion of the a-to-a copy doesn't introduce a use
# after kill of the source vgpr
---
name: look_for_vgpr_killed
tracksRegLiveness: true
body: |
bb.0:
liveins: $agpr0

; GFX908-LABEL: name: look_for_vgpr_killed
; GFX908: liveins: $agpr0
; GFX908-NEXT: {{ $}}
; GFX908-NEXT: $vgpr0 = V_MOV_B32_e32 0, implicit $exec
; GFX908-NEXT: $agpr0 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
; GFX908-NEXT: S_NOP 0, implicit $vgpr0
; GFX908-NEXT: $agpr1 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
;
; GFX90A-LABEL: name: look_for_vgpr_killed
; GFX90A: liveins: $agpr0
; GFX90A-NEXT: {{ $}}
; GFX90A-NEXT: $vgpr0 = V_MOV_B32_e32 0, implicit $exec
; GFX90A-NEXT: $agpr0 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
; GFX90A-NEXT: S_NOP 0, implicit killed $vgpr0
; GFX90A-NEXT: $agpr1 = V_ACCVGPR_MOV_B32 $agpr0, implicit $exec
;
; GFX942-LABEL: name: look_for_vgpr_killed
; GFX942: liveins: $agpr0
; GFX942-NEXT: {{ $}}
; GFX942-NEXT: $vgpr0 = V_MOV_B32_e32 0, implicit $exec
; GFX942-NEXT: $agpr0 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
; GFX942-NEXT: S_NOP 0, implicit killed $vgpr0
; GFX942-NEXT: $agpr1 = V_ACCVGPR_MOV_B32 $agpr0, implicit $exec
$vgpr0 = V_MOV_B32_e32 0, implicit $exec
$agpr0 = COPY $vgpr0
S_NOP 0, implicit killed $vgpr0
$agpr1 = COPY $agpr0

...

---
name: look_for_vgpr_killed_tuple
tracksRegLiveness: true
body: |
bb.0:
liveins: $agpr0

; GFX908-LABEL: name: look_for_vgpr_killed_tuple
; GFX908: liveins: $agpr0
; GFX908-NEXT: {{ $}}
; GFX908-NEXT: $vgpr0 = V_MOV_B32_e32 0, implicit $exec, implicit-def $vgpr0_vgpr1
; GFX908-NEXT: $vgpr1 = V_MOV_B32_e32 1, implicit $exec
; GFX908-NEXT: $agpr0 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
; GFX908-NEXT: S_NOP 0, implicit $vgpr0_vgpr1
; GFX908-NEXT: $agpr1 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
;
; GFX90A-LABEL: name: look_for_vgpr_killed_tuple
; GFX90A: liveins: $agpr0
; GFX90A-NEXT: {{ $}}
; GFX90A-NEXT: $vgpr0 = V_MOV_B32_e32 0, implicit $exec, implicit-def $vgpr0_vgpr1
; GFX90A-NEXT: $vgpr1 = V_MOV_B32_e32 1, implicit $exec
; GFX90A-NEXT: $agpr0 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
; GFX90A-NEXT: S_NOP 0, implicit killed $vgpr0_vgpr1
; GFX90A-NEXT: $agpr1 = V_ACCVGPR_MOV_B32 $agpr0, implicit $exec
;
; GFX942-LABEL: name: look_for_vgpr_killed_tuple
; GFX942: liveins: $agpr0
; GFX942-NEXT: {{ $}}
; GFX942-NEXT: $vgpr0 = V_MOV_B32_e32 0, implicit $exec, implicit-def $vgpr0_vgpr1
; GFX942-NEXT: $vgpr1 = V_MOV_B32_e32 1, implicit $exec
; GFX942-NEXT: $agpr0 = V_ACCVGPR_WRITE_B32_e64 $vgpr0, implicit $exec
; GFX942-NEXT: S_NOP 0, implicit killed $vgpr0_vgpr1
; GFX942-NEXT: $agpr1 = V_ACCVGPR_MOV_B32 $agpr0, implicit $exec
$vgpr0 = V_MOV_B32_e32 0, implicit $exec, implicit-def $vgpr0_vgpr1
$vgpr1 = V_MOV_B32_e32 1, implicit $exec
$agpr0 = COPY $vgpr0
S_NOP 0, implicit killed $vgpr0_vgpr1
$agpr1 = COPY $agpr0

...
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