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Allow machine dce to remove uses in the same instruction
Machine DCE cannot remove a dead definition if there are non-dbg uses. A use however can be in the same instruction: dead %0 = INST %0 Such instructions sometimes created by Detect dead lanes pass. Allow this instruction to be deleted despite the use if the only use belongs to the same instruction. Differential Revision: https://reviews.llvm.org/D59565 llvm-svn: 356619
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# RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -run-pass dead-mi-elimination -o - %s | FileCheck -check-prefix=GCN %s | ||
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||
# GCN-LABEL: name: dead_undef | ||
# GCN: bb.0: | ||
# GCN-NEXT: S_ENDPGM 0 | ||
--- | ||
name: dead_undef | ||
tracksRegLiveness: true | ||
registers: | ||
- { id: 0, class: vgpr_32 } | ||
- { id: 1, class: vgpr_32 } | ||
- { id: 2, class: vgpr_32 } | ||
body: | | ||
bb.0: | ||
%0 = IMPLICIT_DEF | ||
%1 = IMPLICIT_DEF | ||
dead %2:vgpr_32 = V_MAC_F32_e32 %0:vgpr_32, %1:vgpr_32, undef %2:vgpr_32, implicit $exec | ||
S_ENDPGM 0 | ||
# GCN-LABEL: name: dead_defined | ||
# GCN: bb.0: | ||
# GCN-NEXT: S_ENDPGM 0 | ||
--- | ||
name: dead_defined | ||
tracksRegLiveness: true | ||
registers: | ||
- { id: 0, class: vgpr_32 } | ||
- { id: 1, class: vgpr_32 } | ||
- { id: 2, class: vgpr_32 } | ||
body: | | ||
bb.0: | ||
%0 = IMPLICIT_DEF | ||
%1 = IMPLICIT_DEF | ||
%2 = IMPLICIT_DEF | ||
dead %2:vgpr_32 = V_MAC_F32_e32 %0:vgpr_32, %1:vgpr_32, %2:vgpr_32, implicit $exec | ||
S_ENDPGM 0 | ||
# Probably this dead mac can be removed anyway. | ||
# GCN-LABEL: name: dead_def_live_use | ||
# GCN: dead %2:vgpr_32 = V_MAC_F32_e32 %0, %1, %2, implicit $exec | ||
--- | ||
name: dead_def_live_use | ||
tracksRegLiveness: true | ||
registers: | ||
- { id: 0, class: vgpr_32 } | ||
- { id: 1, class: vgpr_32 } | ||
- { id: 2, class: vgpr_32 } | ||
body: | | ||
bb.0: | ||
%0 = IMPLICIT_DEF | ||
%1 = IMPLICIT_DEF | ||
%2 = IMPLICIT_DEF | ||
GLOBAL_STORE_DWORD undef $vgpr0_vgpr1, %2, 0, 0, 0, implicit $exec | ||
dead %2:vgpr_32 = V_MAC_F32_e32 %0:vgpr_32, %1:vgpr_32, %2:vgpr_32, implicit $exec | ||
S_ENDPGM 0 |