llvm-project/llvm/test/CodeGen/AMDGPU/merge-m0.mir

# RUN: llc -march=amdgcn -amdgpu-enable-merge-m0 -verify-machineinstrs -run-pass si-fix-sgpr-copies %s -o - | FileCheck -check-prefix=GCN %s

# GCN:    bb.0.entry:
# GCN:      SI_INIT_M0 -1
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: SI_INIT_M0 65536
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: SI_INIT_M0 -1
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: SI_INIT_M0 65536
# GCN-NEXT: DS_WRITE_B32

# GCN:    bb.1:
# GCN:      SI_INIT_M0 -1
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: DS_WRITE_B32

# GCN:    bb.2:
# GCN:      SI_INIT_M0 65536
# GCN-NEXT: DS_WRITE_B32

# GCN:    bb.3:
# GCN:      SI_INIT_M0 3

# GCN:    bb.4:
# GCN-NOT:  SI_INIT_M0
# GCN:      DS_WRITE_B32
# GCN-NEXT: SI_INIT_M0 4
# GCN-NEXT: DS_WRITE_B32

# GCN:    bb.5:
# GCN-NOT: SI_INIT_M0
# GCN:     DS_WRITE_B32
# GCN-NEXT: SI_INIT_M0 4
# GCN-NEXT: DS_WRITE_B32

# GCN:    bb.6:
# GCN:      SI_INIT_M0 -1,
# GCN-NEXT: DS_WRITE_B32
# GCN:      SI_INIT_M0 %2
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: SI_INIT_M0 %2
# GCN-NEXT: DS_WRITE_B32
# GCN-NEXT: SI_INIT_M0 -1
# GCN-NEXT: DS_WRITE_B32

---
name:            merge-m0-many-init
registers:
  - { id: 0, class: vgpr_32 }
  - { id: 1, class: vgpr_32 }
  - { id: 2, class: sreg_32_xm0 }
body:             |
  bb.0.entry:
    successors: %bb.1, %bb.2

    %0 = IMPLICIT_DEF
    %1 = IMPLICIT_DEF
    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 65536, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 65536, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 65536, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_CBRANCH_VCCZ %bb.1, implicit undef $vcc
    S_BRANCH %bb.2

  bb.1:
    successors: %bb.2
    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.2

  bb.2:
    successors: %bb.3
    SI_INIT_M0 65536, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.3

  bb.3:
    successors: %bb.4, %bb.5
    S_CBRANCH_VCCZ %bb.4, implicit undef $vcc
    S_BRANCH %bb.5

  bb.4:
    successors: %bb.6
    SI_INIT_M0 3, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 4, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.6

  bb.5:
    successors: %bb.6
    SI_INIT_M0 3, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 4, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.6

  bb.6:
    successors: %bb.0.entry, %bb.6
    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    %2 = IMPLICIT_DEF
    SI_INIT_M0 %2, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 %2, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_CBRANCH_VCCZ %bb.6, implicit undef $vcc
    S_BRANCH %bb.0.entry

...

# GCN:    bb.0.entry:
# GCN:      SI_INIT_M0 65536
# GCN-NEXT: DS_WRITE_B32

#GCN:     bb.1:
#GCN-NOT:   SI_INIT_M0 65536
#GCN-NOT:   SI_INIT_M0 -1

#GCN:     bb.2:
#GCN:       SI_INIT_M0 -1

#GCN:     bb.3:
#GCN:       SI_INIT_M0 -1

---
name:            merge-m0-dont-hoist-past-init-with-different-initializer
registers:
  - { id: 0, class: vgpr_32 }
  - { id: 1, class: vgpr_32 }
body:             |
  bb.0.entry:
    successors: %bb.1

    %0 = IMPLICIT_DEF
    %1 = IMPLICIT_DEF
    SI_INIT_M0 65536, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.1

  bb.1:
    successors: %bb.2, %bb.3

    SI_INIT_M0 65536, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_CBRANCH_VCCZ %bb.2, implicit undef $vcc
    S_BRANCH %bb.3

  bb.2:
    successors: %bb.4

    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.4

  bb.3:
    successors: %bb.4

    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.4

  bb.4:
    S_ENDPGM 0
...

# GCN:    bb.0.entry:
# GCN-NOT:  SI_INIT_M0
# GCN:      S_OR_B64
# GCN-NEXT: SI_INIT_M0

#GCN:     bb.1:
#GCN-NOT:   SI_INIT_M0 -1

#GCN:     bb.2:
#GCN-NOT:   SI_INIT_MO -1

---
name:            merge-m0-after-prologue
registers:
  - { id: 0, class: vgpr_32 }
  - { id: 1, class: vgpr_32 }
body:             |
  bb.0.entry:
    successors: %bb.1, %bb.2
    liveins: $sgpr0_sgpr1

    $exec = S_OR_B64 $exec, killed $sgpr0_sgpr1, implicit-def $scc
    %0 = IMPLICIT_DEF
    %1 = IMPLICIT_DEF
    S_CBRANCH_VCCZ %bb.1, implicit undef $vcc
    S_BRANCH %bb.2

  bb.1:
    successors: %bb.3

    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.3

  bb.2:
    successors: %bb.3

    SI_INIT_M0 -1, implicit-def $m0
    DS_WRITE_B32 %0, %1, 0, 0, implicit $m0, implicit $exec
    S_BRANCH %bb.3

  bb.3:
    S_ENDPGM 0
...