llvm-project/llvm/test/CodeGen/AMDGPU/fold-multiple.mir

# RUN: llc --mtriple=amdgcn--amdhsa -mcpu=fiji -verify-machineinstrs -run-pass si-fold-operands,si-shrink-instructions %s -o - | FileCheck %s
--- |
  define amdgpu_kernel void @test() #0 {
    ret void
  }

  attributes #0 = { nounwind }

...
---

# This used to crash / trigger an assertion, because re-scanning the use list
# after constant-folding the definition of %3 lead to the definition of %2
# being processed twice.

# CHECK-LABEL: name: test
# CHECK: %2:vgpr_32 = V_LSHLREV_B32_e32 2, killed %0, implicit $exec
# CHECK: %4:vgpr_32 = V_AND_B32_e32 8, killed %2, implicit $exec

name:            test
tracksRegLiveness: true
registers:
  - { id: 0, class: vgpr_32 }
  - { id: 1, class: sreg_32 }
  - { id: 2, class: vgpr_32 }
  - { id: 3, class: sreg_32 }
  - { id: 4, class: vgpr_32 }
  - { id: 5, class: sgpr_128 }
body:             |
  bb.0 (%ir-block.0):
    %0 = IMPLICIT_DEF
    %1 = S_MOV_B32 2
    %2 = V_LSHLREV_B32_e64 %1, killed %0, implicit $exec
    %3 = S_LSHL_B32 %1, killed %1, implicit-def dead $scc
    %4 = V_AND_B32_e64 killed %2, killed %3, implicit $exec
    %5 = IMPLICIT_DEF
    BUFFER_STORE_DWORD_OFFSET killed %4, killed %5, 0, 0, 0, 0, 0, 0, 0, implicit $exec
    S_ENDPGM 0

...