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[AMDGPU] Cleanup hasUnwantedEffectsWhenEXECEmpty function #70206

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Merged
merged 1 commit into from
Oct 25, 2023
Merged

[AMDGPU] Cleanup hasUnwantedEffectsWhenEXECEmpty function #70206

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3 changes: 1 addition & 2 deletions llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3906,8 +3906,7 @@ bool SIInstrInfo::hasUnwantedEffectsWhenEXECEmpty(const MachineInstr &MI) const
//
// However, executing them with EXEC = 0 causes them to operate on undefined
// data, which we avoid by returning true here.
if (Opcode == AMDGPU::V_READFIRSTLANE_B32 ||
Opcode == AMDGPU::V_READLANE_B32 || Opcode == AMDGPU::V_WRITELANE_B32)
if (Opcode == AMDGPU::V_READFIRSTLANE_B32)
return true;

return false;
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14 changes: 6 additions & 8 deletions llvm/test/CodeGen/AMDGPU/remove-short-exec-branches-special-instructions.mir
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Expand Up @@ -130,13 +130,12 @@ body: |

---

name: need_skip_writelane_b32
name: dont_skip_writelane_b32
body: |
; CHECK-LABEL: name: need_skip_writelane_b32
; CHECK-LABEL: name: dont_skip_writelane_b32
; CHECK: bb.0:
; CHECK-NEXT: successors: %bb.1(0x40000000), %bb.2(0x40000000)
; CHECK-NEXT: successors: %bb.1(0x40000000)
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: S_CBRANCH_EXECZ %bb.2, implicit $exec
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.1:
; CHECK-NEXT: successors: %bb.2(0x80000000)
Expand All @@ -160,13 +159,12 @@ body: |
...

---
name: need_skip_readlane_b32
name: dont_skip_readlane_b32
body: |
; CHECK-LABEL: name: need_skip_readlane_b32
; CHECK-LABEL: name: dont_skip_readlane_b32
; CHECK: bb.0:
; CHECK-NEXT: successors: %bb.1(0x40000000), %bb.2(0x40000000)
; CHECK-NEXT: successors: %bb.1(0x40000000)
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: S_CBRANCH_EXECZ %bb.2, implicit $exec
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.1:
; CHECK-NEXT: successors: %bb.2(0x80000000)
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