waitcnt-loop-irreducible.mir 2.81 KB
# RUN: llc -march=amdgcn -mcpu=gfx803 -verify-machineinstrs -run-pass si-insert-waitcnts -o - %s | FileCheck -check-prefixes=GCN,GFX8 %s
# RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs -run-pass si-insert-waitcnts -o - %s | FileCheck -check-prefixes=GCN,GFX9 %s

--- |

  define amdgpu_ps void @irreducible_loop() {
    ret void
  }
  define amdgpu_ps void @irreducible_loop_extended() {
    ret void
  }

...
---

# GCN-LABEL: name: irreducible_loop{{$}}
# GCN: S_LOAD_DWORDX4_IMM
# GFX8: S_WAITCNT 127{{$}}
# GFX9: S_WAITCNT 49279{{$}}
# GCN: S_BUFFER_LOAD_DWORD_IMM
# GFX8: S_WAITCNT 127{{$}}
# GFX9: S_WAITCNT 49279{{$}}
# GCN: S_CMP_GE_I32
name:            irreducible_loop
body:             |
  bb.0:
    successors: %bb.3, %bb.2

    S_CBRANCH_VCCZ %bb.2, implicit $vcc
    S_BRANCH %bb.3

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

    S_CBRANCH_VCCNZ %bb.3, implicit $vcc

  bb.2:
    successors: %bb.3

    renamable $sgpr4_sgpr5_sgpr6_sgpr7 = S_LOAD_DWORDX4_IMM renamable $sgpr0_sgpr1, 0, 0, 0
    renamable $sgpr3 = S_BUFFER_LOAD_DWORD_IMM killed renamable $sgpr4_sgpr5_sgpr6_sgpr7, 0, 0, 0

  bb.3:
    successors: %bb.1, %bb.4

    S_CMP_GE_I32 renamable $sgpr2, renamable $sgpr3, implicit-def $scc
    S_CBRANCH_SCC0 %bb.1, implicit killed $scc

  bb.4:

    S_ENDPGM 0

...

# GCN-LABEL: name: irreducible_loop_extended

# GCN: S_LOAD_DWORDX4_IMM
# GFX8: S_WAITCNT 127{{$}}
# GFX9: S_WAITCNT 49279{{$}}
# GCN: BUFFER_STORE_DWORD_OFFEN_exact
# GFX8: S_WAITCNT 127{{$}}
# GFX9: S_WAITCNT 49279{{$}}
# GCN: BUFFER_STORE_DWORD_OFFEN_exact
# GCN: S_LOAD_DWORDX4_IMM
# GFX8: S_WAITCNT 127{{$}}
# GFX9: S_WAITCNT 49279{{$}}
# GCN: BUFFER_ATOMIC_ADD_OFFSET_RTN
# GCN: S_WAITCNT 3952
# GCN: FLAT_STORE_DWORD
# GCN: S_ENDPGM 0
name: irreducible_loop_extended

body: |
  bb.0:
    successors: %bb.1, %bb.2
    $sgpr4_sgpr5_sgpr6_sgpr7 = S_LOAD_DWORDX4_IMM renamable $sgpr2_sgpr3, 0, 0, 0
    S_CBRANCH_VCCZ %bb.2, implicit $vcc

  bb.1:
    successors: %bb.2
    BUFFER_STORE_DWORD_OFFEN_exact killed renamable $vgpr3, renamable $vgpr2, renamable $sgpr4_sgpr5_sgpr6_sgpr7, 0, 0, 0, 0, 0, 0, 0, implicit $exec

  bb.2:
    successors: %bb.3, %bb.6
    S_CBRANCH_VCCNZ %bb.6, implicit $vcc

  bb.3:
    successors: %bb.4, %bb.5
    BUFFER_STORE_DWORD_OFFEN_exact killed renamable $vgpr3, killed renamable $vgpr2, killed renamable $sgpr4_sgpr5_sgpr6_sgpr7, 0, 0, 0, 0, 0, 0, 0, implicit $exec
    S_CBRANCH_VCCNZ %bb.5, implicit $vcc

  bb.4:
    successors: %bb.5
    renamable $sgpr12_sgpr13_sgpr14_sgpr15 = S_LOAD_DWORDX4_IMM killed renamable $sgpr2_sgpr3, 64, 0, 0
    renamable $vgpr2 = BUFFER_ATOMIC_ADD_OFFSET_RTN killed renamable $vgpr2, killed renamable $sgpr12_sgpr13_sgpr14_sgpr15, 0, 0, 0, implicit $exec

  bb.5:
    successors: %bb.6

  bb.6:
    FLAT_STORE_DWORD $vgpr3_vgpr4, $vgpr2, 0, 0, 0, 0, implicit $exec, implicit $flat_scr
    S_ENDPGM 0
...