llvm/test/DebugInfo/MIR/InstrRef/expr-operand-count-mismatch.mir

# RUN: llc %s -o - -experimental-debug-variable-locations=true \
# RUN:     -run-pass=livedebugvalues | FileCheck %s
#
## Two debug values for the same variable can carry identical DIExpressions
## while having different numbers of location operands.
## Here both values use the same empty !DIExpression(), but %entry describes
## the variable with two location operands and %then with one.
##
## LiveDebugValues joins values by pairing their location operands up by index,
## and used to decide two values were joinable by comparing expressions alone.
## When the counts disagreed it read past the end of the shorter value's
## operand list. Check that we no longer do so, and that no location is
## propagated into the join block, where the two counts disagree.
#
# CHECK: ![[VAR:[0-9]+]] = !DILocalVariable(name: "x"
#
# CHECK-LABEL: bb.0.entry:
# CHECK:       DBG_VALUE_LIST ![[VAR]], !DIExpression(), $edi, $edi, debug-location
#
# CHECK-LABEL: bb.1.then:
# CHECK:       DBG_VALUE_LIST ![[VAR]], !DIExpression(), $edi, $edi, debug-location
# CHECK:       DBG_VALUE_LIST ![[VAR]], !DIExpression(), $edi, debug-location
#
# CHECK-LABEL: bb.2.exit:
# CHECK-NOT:   DBG_VALUE

--- |
  target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-unknown"

  define i32 @f(i32 %a, i1 %c) !dbg !4 {
  entry:
    %v = add i32 %a, 1, !dbg !7
    br i1 %c, label %exit, label %then

  then:                                             ; preds = %entry
    %t = mul i32 %v, 3, !dbg !7
    br label %exit

  exit:                                             ; preds = %then, %entry
    %p = phi i32 [ %t, %then ], [ 0, %entry ], !dbg !7
    ret i32 %p, !dbg !7
  }

  !llvm.dbg.cu = !{!0}
  !llvm.module.flags = !{!3}

  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "hand-written", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
  !1 = !DIFile(filename: "min.c", directory: "/")
  !2 = !{}
  !3 = !{i32 2, !"Debug Info Version", i32 3}
  !4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !5, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
  !5 = distinct !DISubroutineType(types: !6)
  !6 = !{null}
  !7 = !DILocation(line: 1, column: 1, scope: !4)
  !8 = !DILocalVariable(name: "x", scope: !4, file: !1, line: 1, type: !9)
  !9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
...
---
name:            f
alignment:       1
tracksRegLiveness: true
debugInstrRef:   true
tracksDebugUserValues: true
liveins:
  - { reg: '$edi', virtual-reg: '' }
  - { reg: '$esi', virtual-reg: '' }
body:             |
  bb.0.entry:
    successors: %bb.2(0x40000000), %bb.1(0x40000000)
    liveins: $edi, $esi

    renamable $edi = KILL $edi, implicit-def $rdi
    DBG_VALUE_LIST !8, !DIExpression(), $edi, $edi, debug-location !7
    renamable $eax = XOR32rr undef $eax, undef $eax, implicit-def dead $eflags
    TEST8ri renamable $sil, 1, implicit-def $eflags, implicit killed $esi
    JCC_1 %bb.2, 5, implicit $eflags

  bb.1.then:
    successors: %bb.2(0x80000000)
    liveins: $rdi

    renamable $edi = INC32r renamable $edi, implicit-def dead $eflags, implicit killed $rdi, implicit-def $rdi, debug-location !7
    DBG_VALUE_LIST !8, !DIExpression(), $edi, debug-location !7
    renamable $eax = LEA64_32r killed renamable $rdi, 2, renamable $rdi, 0, $noreg, debug-location !7

  bb.2.exit:
    liveins: $eax

    RET64 $eax, debug-location !7
...