llvm/test/CodeGen/AMDGPU/coalescer-remat-dead-use.mir

# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
# RUN: llc -mtriple=amdgcn -mcpu=gfx900 -o - -verify-coalescing -run-pass=register-coalescer %s | FileCheck -check-prefix=GCN %s

---
# Do not rematerialize V_MOV_B32 at COPY because source register %1 is killed.

name:            no_remat_killed_src_in_inst
tracksRegLiveness: true
body:             |
  bb.0:
    liveins: $vgpr0

    ; GCN-LABEL: name: no_remat_killed_src_in_inst
    ; GCN: liveins: $vgpr0
    ; GCN-NEXT: {{  $}}
    ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
    ; GCN-NEXT: [[V_ADD_U32_e32_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e32 1, [[COPY]], implicit $exec
    ; GCN-NEXT: [[V_MOV_B32_e32_:%[0-9]+]]:vgpr_32 = V_MOV_B32_e32 [[V_ADD_U32_e32_]], implicit $exec
    ; GCN-NEXT: $vgpr0 = COPY [[V_MOV_B32_e32_]]
    ; GCN-NEXT: SI_RETURN_TO_EPILOG $vgpr0
    %0:vgpr_32 = COPY $vgpr0
    %1:vgpr_32 = V_ADD_U32_e32 1, %0, implicit $exec
    %2:vgpr_32 = V_MOV_B32_e32 killed %1, implicit $exec
    $vgpr0 = COPY killed %2
    SI_RETURN_TO_EPILOG killed $vgpr0
...
---
# Do not rematerialize V_MOV_B32 at COPY because source register %1 is killed
# after the MOV but before the COPY.

name:            no_remat_killed_src_after_inst
tracksRegLiveness: true
body:             |
  bb.0:
    liveins: $vgpr0

    ; GCN-LABEL: name: no_remat_killed_src_after_inst
    ; GCN: liveins: $vgpr0
    ; GCN-NEXT: {{  $}}
    ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
    ; GCN-NEXT: [[V_ADD_U32_e32_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e32 1, [[COPY]], implicit $exec
    ; GCN-NEXT: [[V_MOV_B32_e32_:%[0-9]+]]:vgpr_32 = V_MOV_B32_e32 [[V_ADD_U32_e32_]], implicit $exec
    ; GCN-NEXT: KILL [[V_ADD_U32_e32_]]
    ; GCN-NEXT: $vgpr0 = COPY [[V_MOV_B32_e32_]]
    ; GCN-NEXT: SI_RETURN_TO_EPILOG $vgpr0
    %0:vgpr_32 = COPY $vgpr0
    %1:vgpr_32 = V_ADD_U32_e32 1, %0, implicit $exec
    %2:vgpr_32 = V_MOV_B32_e32 %1, implicit $exec
    KILL %1
    $vgpr0 = COPY killed %2
    SI_RETURN_TO_EPILOG killed $vgpr0
...
---
# Even if %1 is not killed do not rematerialize V_MOV_B32 so that we do not
# extend %1 liverange.

name:            no_remat_alive_src_in_inst_unused
tracksRegLiveness: true
body:             |
  bb.0:
    liveins: $vgpr0

    ; GCN-LABEL: name: no_remat_alive_src_in_inst_unused
    ; GCN: liveins: $vgpr0
    ; GCN-NEXT: {{  $}}
    ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
    ; GCN-NEXT: [[V_ADD_U32_e32_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e32 1, [[COPY]], implicit $exec
    ; GCN-NEXT: [[V_MOV_B32_e32_:%[0-9]+]]:vgpr_32 = V_MOV_B32_e32 [[V_ADD_U32_e32_]], implicit $exec
    ; GCN-NEXT: $vgpr0 = COPY [[V_MOV_B32_e32_]]
    ; GCN-NEXT: SI_RETURN_TO_EPILOG $vgpr0
    %0:vgpr_32 = COPY $vgpr0
    %1:vgpr_32 = V_ADD_U32_e32 1, %0, implicit $exec
    %2:vgpr_32 = V_MOV_B32_e32 %1, implicit $exec
    $vgpr0 = COPY killed %2
    SI_RETURN_TO_EPILOG killed $vgpr0
...
---
# Rematerialize V_MOV_B32 since %1 is available at COPY and still alive.

name:            remat_alive_src_in_inst_used_and_available
tracksRegLiveness: true
body:             |
  bb.0:
    liveins: $vgpr0

    ; GCN-LABEL: name: remat_alive_src_in_inst_used_and_available
    ; GCN: liveins: $vgpr0
    ; GCN-NEXT: {{  $}}
    ; GCN-NEXT: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
    ; GCN-NEXT: [[V_ADD_U32_e32_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e32 1, [[COPY]], implicit $exec
    ; GCN-NEXT: $vgpr0 = V_MOV_B32_e32 [[V_ADD_U32_e32_]], implicit $exec
    ; GCN-NEXT: SI_RETURN_TO_EPILOG $vgpr0, implicit [[V_ADD_U32_e32_]]
    %0:vgpr_32 = COPY $vgpr0
    %1:vgpr_32 = V_ADD_U32_e32 1, %0, implicit $exec
    %2:vgpr_32 = V_MOV_B32_e32 %1, implicit $exec
    $vgpr0 = COPY killed %2
    SI_RETURN_TO_EPILOG killed $vgpr0, implicit %1
...