llvm-project/llvm/test/CodeGen/AMDGPU/phi-elimination-end-cf.mir

# RUN: llc -mtriple amdgcn -run-pass livevars -run-pass phi-node-elimination -verify-machineinstrs -o - %s | FileCheck %s

# CHECK-LABEL:  phi-cf-test
# CHECK: bb.0:
# CHECK:     [[COND:%[0-9]+]]:sreg_64 = V_CMP_EQ_U32_e64
# CHECK:     [[IF_SOURCE0:%[0-9]+]]:sreg_64 = SI_IF [[COND]], %bb.1, implicit-def dead $exec, implicit-def dead $scc, implicit $exec
# CHECK:     [[IF_INPUT_REG:%[0-9]+]]:sreg_64 = S_MOV_B64_term killed [[IF_SOURCE0]], implicit $exec

# CHECK: bb.1:
# CHECK:     [[END_CF_ARG:%[0-9]+]]:sreg_64 = COPY killed [[IF_INPUT_REG]]
# CHECK:     SI_END_CF killed [[END_CF_ARG]], implicit-def dead $exec, implicit-def dead $scc, implicit $exec

# CHECK: bb.2:
# CHECK:     [[IF_SOURCE1:%[0-9]+]]:sreg_64 = SI_IF [[COND]], %bb.1, implicit-def dead $exec, implicit-def dead $scc, implicit $exec
# CHECK:     [[IF_INPUT_REG]]:sreg_64 = S_MOV_B64_term killed [[IF_SOURCE1]], implicit $exec


...
---
name:            phi-cf-test
tracksRegLiveness: true
body:             |

  bb.0:
    successors: %bb.3(0x40000000), %bb.2(0x40000000)
    liveins: $vgpr0

    %5:vgpr_32(s32) = COPY $vgpr0
    %0:sreg_64 = V_CMP_EQ_U32_e64 0, %5(s32), implicit $exec
    %18:vgpr_32 = V_MOV_B32_e32 0, implicit $exec
    %22:sreg_64 = SI_IF %0, %bb.2, implicit-def dead $exec, implicit-def dead $scc, implicit $exec
    S_BRANCH %bb.3

  bb.2:
    successors: %bb.3(0x80000000)

    %24:sreg_64 = PHI %20, %bb.3, %22, %bb.0
    %23:vgpr_32 = PHI %19, %bb.3, %18, %bb.0
    SI_END_CF %24, implicit-def dead $exec, implicit-def dead $scc, implicit $exec
    %3:vgpr_32, dead %10:sreg_64 = nsw V_ADD_CO_U32_e64 1, %23, 0, implicit $exec

  bb.3:
    successors: %bb.3(0x40000000), %bb.2(0x40000000)

    %4:vgpr_32 = PHI %19, %bb.3, %3, %bb.2, %18, %bb.0
    %15:sreg_32_xm0 = S_MOV_B32 61440
    %16:sreg_32_xm0 = S_MOV_B32 -1
    %17:sgpr_128 = REG_SEQUENCE undef %14:sreg_32_xm0, %subreg.sub0, undef %12:sreg_32_xm0, %subreg.sub1, %16, %subreg.sub2, %15, %subreg.sub3
    BUFFER_STORE_DWORD_OFFSET %4, %17, 0, 0, 0, 0, 0, 0, 0, implicit $exec :: (volatile store 4 into `i32 addrspace(1)* undef`, addrspace 1)
    %19:vgpr_32 = COPY %4
    %20:sreg_64 = SI_IF %0, %bb.2, implicit-def dead $exec, implicit-def dead $scc, implicit $exec
    S_BRANCH %bb.3

...