third_party/llvm-project/llvm/test/CodeGen/MIR/X86/undefined-virtual-register.mir

# RUN: not llc -march=x86-64 -run-pass none -o /dev/null %s 2>&1 | FileCheck %s
# This test ensures that the MIR parser reports an error when parsing a
# reference to an undefined virtual register.

--- |

  define i32 @test(i32 %a) {
  entry:
    ret i32 %a
  }

...
---
name:            test
tracksRegLiveness: true
registers:
  - { id: 0, class: gr32 }
body: |
  bb.0.entry:
    %0 = COPY $edi
    ; CHECK: Cannot determine class/bank of virtual register 1 in function 'test'
    $eax = COPY %1
    RETQ $eax
...