# RUN: llc -o - %s -mtriple=amdgcn-amd-amdhsa-opencl -run-pass=simple-register-coalescing | FileCheck %s
---
# Checks for a bug where subregister liveranges were not properly pruned for
# an IMPLCITI_DEF that gets removed completely.
#
# CHECK-LABEL: name: func
# IMPLICIT_DEF should be gone without llc hitting assertion failures.
# CHECK-NOT: IMPLICIT_DEF
name: func
tracksRegLiveness: true
body: |
  bb.0:
    undef %5.sub1 = V_MOV_B32_e32 0, implicit %exec
    %6 = COPY %5
    S_CBRANCH_VCCZ %bb.2, implicit undef %vcc

  bb.1:
    %1 : sreg_32_xm0 = S_MOV_B32 0
    undef %0.sub0 : sreg_64 = COPY %1
    %0.sub1 = COPY %1
    %4 : vreg_64 = COPY killed %0
    %5 : vreg_64 = IMPLICIT_DEF
    %6 : vreg_64 = COPY killed %4

  bb.2:
    %2 : vgpr_32 = V_CVT_F32_I32_e32 killed %5.sub1, implicit %exec

  bb.3:
    %3 : vgpr_32 = V_CVT_F32_I32_e32 killed %6.sub1, implicit %exec
    S_ENDPGM
...