test/CodeGen/AMDGPU/regcoalesce-keep-valid-lanes-implicit-def-bug39602.mir

# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
# RUN: llc -mtriple=amdgcn-amd-amdhsa -verify-coalescing -run-pass=simple-register-coalescing -verify-machineinstrs -o - %s | FileCheck %s

# Bug 39602: Avoid "Couldn't join subrange" error when clearing valid
# lanes on an implicit_def that later cannot be erased.

---
name: lost_valid_lanes_maybe_erasable_implicit_def
tracksRegLiveness: true
body:             |
  ; CHECK-LABEL: name: lost_valid_lanes_maybe_erasable_implicit_def
  ; CHECK: bb.0:
  ; CHECK:   successors: %bb.1(0x80000000)
  ; CHECK:   undef %0.sub1:sreg_64 = IMPLICIT_DEF
  ; CHECK: bb.1:
  ; CHECK:   %0.sub0:sreg_64 = S_MOV_B32 0
  ; CHECK:   [[COPY:%[0-9]+]]:sreg_64 = COPY %0
  ; CHECK:   dead %0.sub1:sreg_64 = COPY %0.sub0
  ; CHECK:   S_ENDPGM 0, implicit [[COPY]].sub1
  bb.0:
    successors: %bb.1
    undef %0.sub1:sreg_64 = IMPLICIT_DEF

  bb.1:
    %0.sub0:sreg_64 = S_MOV_B32 0
    %1:sreg_64 = COPY %0:sreg_64
    dead %0.sub1:sreg_64 = COPY %0.sub0:sreg_64
    S_ENDPGM 0, implicit %1.sub1:sreg_64

...
---
# Same as previous, except with a real value instead of
# IMPLICIT_DEF. These should both be handled the same way.

name:  lost_valid_lanes_real_value
tracksRegLiveness: true
body:             |
  ; CHECK-LABEL: name: lost_valid_lanes_real_value
  ; CHECK: bb.0:
  ; CHECK:   successors: %bb.1(0x80000000)
  ; CHECK:   undef %0.sub1:sreg_64 = S_MOV_B32 -1
  ; CHECK: bb.1:
  ; CHECK:   %0.sub0:sreg_64 = S_MOV_B32 0
  ; CHECK:   [[COPY:%[0-9]+]]:sreg_64 = COPY %0
  ; CHECK:   dead %0.sub1:sreg_64 = COPY %0.sub0
  ; CHECK:   S_ENDPGM 0, implicit [[COPY]].sub1
  bb.0:
    successors: %bb.1
    undef %0.sub1:sreg_64 = S_MOV_B32 -1

  bb.1:
    %0.sub0:sreg_64 = S_MOV_B32 0
    %1:sreg_64 = COPY %0:sreg_64
    dead %0.sub1:sreg_64 = COPY %0.sub0:sreg_64
    S_ENDPGM 0, implicit %1.sub1:sreg_64

...