# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
# RUN: llc -mtriple=amdgcn -mcpu=gfx900 -run-pass register-coalescer -verify-machineinstrs -o - %s | FileCheck %s
#
# The failure occurs when the coalescer tries to removePartialRedundency() on the
# "%2:vreg_64 = COPY %3" in bb.1. The coalescer tries to prune and extend each
# subrange of %2, the subrange for %2.sub1 has a def location (in bb.2) in the
# predecessor path 2->3->1. But for another predecessor path 0->4->1,
# the subrange has only one undef location in bb.0. If we don't compute Undef set,
# it will fail to find the reaching def for %2.sub1 in predecessor bb.4 and bb.0
# and crash with error message:
# "Use of $noreg does not have a corresponding definition on every path
# LLVM ERROR: Use not jointly dominated by defs"
---
name: _amdgpu_ps_main
alignment: 1
tracksRegLiveness: true
body: |
; CHECK-LABEL: name: _amdgpu_ps_main
; CHECK: bb.0:
; CHECK-NEXT: successors: %bb.2(0x40000000), %bb.4(0x40000000)
; CHECK-NEXT: liveins: $sgpr2, $sgpr3, $vgpr3
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: [[COPY:%[0-9]+]]:sgpr_32 = COPY $sgpr2
; CHECK-NEXT: undef [[COPY1:%[0-9]+]].sub0:vreg_64 = COPY [[COPY]]
; CHECK-NEXT: undef [[COPY2:%[0-9]+]].sub0:vreg_64 = COPY [[COPY]]
; CHECK-NEXT: S_CBRANCH_VCCNZ %bb.2, implicit undef $vcc
; CHECK-NEXT: S_BRANCH %bb.4
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.1:
; CHECK-NEXT: successors: %bb.2(0x80000000)
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: S_NOP 0, implicit [[COPY2]].sub0
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.2:
; CHECK-NEXT: successors: %bb.3(0x04000000), %bb.2(0x7c000000)
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: [[COPY3:%[0-9]+]]:vreg_64 = COPY [[COPY2]]
; CHECK-NEXT: [[COPY1:%[0-9]+]].sub0:vreg_64 = COPY [[COPY3]].sub0
; CHECK-NEXT: [[COPY2:%[0-9]+]]:vreg_64 = COPY [[COPY1]]
; CHECK-NEXT: S_CBRANCH_EXECNZ %bb.2, implicit undef $exec
; CHECK-NEXT: S_BRANCH %bb.3
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.3:
; CHECK-NEXT: successors: %bb.1(0x80000000)
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: [[COPY2:%[0-9]+]]:vreg_64 = COPY [[COPY3]]
; CHECK-NEXT: S_BRANCH %bb.1
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.4:
; CHECK-NEXT: successors: %bb.1(0x80000000)
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: S_BRANCH %bb.1
bb.0:
liveins: $sgpr2, $sgpr3, $vgpr3
%0:sgpr_32 = COPY $sgpr2
undef %1.sub0:vreg_64 = COPY %0
undef %2.sub0:vreg_64 = COPY %0
S_CBRANCH_VCCNZ %bb.2, implicit undef $vcc
S_BRANCH %bb.4
bb.1:
%2:vreg_64 = COPY %3
S_NOP 0, implicit %2.sub0
bb.2:
successors: %bb.3(0x04000000), %bb.2(0x7c000000)
%3:vreg_64 = COPY %2
%1.sub0:vreg_64 = COPY %3.sub0
%2:vreg_64 = COPY %1
S_CBRANCH_EXECNZ %bb.2, implicit undef $exec
S_BRANCH %bb.3
bb.3:
S_BRANCH %bb.1
bb.4:
%3:vreg_64 = COPY %2
S_BRANCH %bb.1
...
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