llvm/test/DebugInfo/MIR/InstrRef/memory-operand-tracking.mir

# RUN: llc %s -march=x86-64 -run-pass=livedebugvalues \
# RUN:      -mtriple x86_64-unknown-unknown \
# RUN:      -experimental-debug-variable-locations -o - 2>&1 \
# RUN: | FileCheck %s
#
# Test that memory operands of instructions are interpreted by LiveDebugValues:
# if an instruction reference is substituted to a memory operand, we should be
# able to emit a DBG_VALUE referring to its slot.
#
# In addition, further instructions that write to the same stack slot should
# be recognised as clobbering the value in that slot.
--- |
  define i8 @test(i32 %bar) local_unnamed_addr !dbg !7 {
  entry:
    ret i8 0, !dbg !12
  }

  declare dso_local void @ext(i64)

  !llvm.dbg.cu = !{!0}
  !llvm.module.flags = !{!3, !4, !5, !6}
  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
  !1 = !DIFile(filename: "foo.cpp", directory: ".")
  !2 = !DIBasicType(name: "int", size: 8, encoding: DW_ATE_signed)
  !3 = !{i32 2, !"Dwarf Version", i32 4}
  !4 = !{i32 2, !"Debug Info Version", i32 3}
  !5 = !{i32 1, !"wchar_size", i32 2}
  !6 = !{i32 7, !"PIC Level", i32 2}
  !7 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: !1, file: !1, line: 6, type: !8, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
  !8 = !DISubroutineType(types: !9)
  !9 = !{!2, !2}
  !10 = !{!11}
  !11 = !DILocalVariable(name: "baz", scope: !7, file: !1, line: 7, type: !2)
  !12 = !DILocation(line: 10, scope: !7)
...
---
name: test
tracksRegLiveness: true
liveins:
  - { reg: '$rdi', virtual-reg: '' }
debugValueSubstitutions:
- { srcinst: 2, srcop: 0, dstinst: 3, dstop: 1000000, subreg: 0 }
- { srcinst: 4, srcop: 0, dstinst: 5, dstop: 1000000, subreg: 0 }
stack:
  - { id: 0, name: '', type: spill-slot, offset: -16, size: 8, alignment: 8,
      stack-id: default, callee-saved-register: '', callee-saved-restored: true,
      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
body:  |
  bb.0:
  liveins: $rdi, $rax
    DBG_PHI $rax, 1
    MOV64mr $rsp, 1, $noreg, 16, $noreg, $rdi :: (store 8 into %stack.0)
    $rax = MOV64ri 0, debug-location !12
    INC32m $rsp, 1, $noreg, 4, $noreg, implicit-def dead $eflags, debug-instr-number 3, debug-location !DILocation(line: 0, scope: !7) :: (store (s32) into %stack.0)
    DBG_INSTR_REF 2, 0, !11, !DIExpression(), debug-location !12
    ; CHECK:      DBG_INSTR_REF 2, 0
    ; CHECK-NEXT: DBG_VALUE $rsp
    ;; Test that the old value (from the DBG_PHI) is not tracked anywhere. It
    ;; should not be considered as being on the stack any more.
    DBG_INSTR_REF 1, 0, !11, !DIExpression(), debug-location !12
    ; CHECK:      DBG_INSTR_REF 1, 0
    ; CHECK-NEXT: DBG_VALUE $noreg
    INC32m $rsp, 1, $noreg, 4, $noreg, implicit-def dead $eflags, debug-location !12 :: (store (s32) into %stack.0)
    ;; The above INC32m should be detected as clobbering the stack location,
    ;; even though it isn't debug labelled.
    DBG_INSTR_REF 2, 0, !11, !DIExpression(), debug-location !12
    ; CHECK:      DBG_INSTR_REF 2, 0
    ; CHECK-NEXT: DBG_VALUE $noreg

    ;; Store another debug-labelled value to the stack,
    INC32m $rsp, 1, $noreg, 4, $noreg, implicit-def dead $eflags, debug-instr-number 5, debug-location !DILocation(line: 0, scope: !7) :: (store (s32) into %stack.0)
    ;; Point the variable at that value.
    DBG_INSTR_REF 4, 0, !11, !DIExpression(), debug-location !12
    ; CHECK:      DBG_INSTR_REF 4, 0,
    ; CHECK-NEXT: DBG_VALUE $rsp
    ;; Overwrite the stack: LiveDebugValues should explicitly undef the stack
    ;; location with DBG_VALUE $noreg, as DbgEntityHistoryCalculator doesn't
    ;; look at the stack.
    INC32m $rsp, 1, $noreg, 4, $noreg, implicit-def dead $eflags, debug-location !DILocation(line: 0, scope: !7) :: (store (s32) into %stack.0)
    ; CHECK:      INC32m $rsp
    ; CHECK-NEXT: DBG_VALUE $noreg

    $rax = MOV64rm $rsp, 1, $noreg, 8, $noreg :: (load 8 from %stack.0)
    RET64 $rax, debug-location !12
...