postra-subreg-sink.mir 4.11 KB
# RUN: llc  -mtriple=x86_64-unknown-unknown %s -run-pass=postra-machine-sink -o - | FileCheck %s
# Test that when we run the postra machine sinker (which sinks COPYs), that
# DBG_VALUEs of both sub and super-registers that depend on such COPYs are
# sunk with them.
--- |
  ; Module stripped of everything, MIR below is what's interesting
  ; ModuleID = '<stdin>'
  source_filename = "justacall.cpp"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"

  ; Function Attrs: noinline norecurse nounwind uwtable
  define dso_local i32 @main(i32 %argc, i8** nocapture readnone %argv) !dbg !14 {
  entry:
    br label %return
  return:
    ret i32 0
  }

  !llvm.dbg.cu = !{!2}
  !llvm.module.flags = !{!1, !1000}

  !0 = !{!"dummy metadata"}
  !1 = !{i32 2, !"Dwarf Version", i32 4}
  !1000 = !{i32 2, !"Debug Info Version", i32 3}
  !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, nameTableKind: None)
  !3 = !DIFile(filename: "justacall.cpp", directory: "/tmp")
  !4 = !{}
  !7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
  !8 = !DIBasicType(name: "int", size: 8, encoding: DW_ATE_signed)
  !9 = !DIBasicType(name: "int", size: 16, encoding: DW_ATE_signed)
  !14 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 7, type: !15, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: true, unit: !2, retainedNodes: !20)
  !15 = !DISubroutineType(types: !16)
  !16 = !{!7, !7}
  !20 = !{!21, !22, !23, !24}
  !21 = !DILocalVariable(name: "argc", arg: 1, scope: !14, file: !3, line: 7, type: !7)
  !22 = !DILocalVariable(name: "foo", scope: !14, file: !3, line: 7, type: !8)
  !23 = !DILocalVariable(name: "bar", scope: !14, file: !3, line: 7, type: !7)
  !24 = !DILocalVariable(name: "baz", scope: !14, file: !3, line: 7, type: !9)
  !100 = !DILocation(line: 1, scope: !14)

...
---
name:            main
tracksRegLiveness: true
registers:
liveins:
  - { reg: '$edi', virtual-reg: '' }
frameInfo:
  hasCalls:        true
fixedStack:
stack:
constants:
body:             |

  ; CHECK: ![[ARGVAR:[0-9]+]] = !DILocalVariable(name: "argc",
  ; CHECK: ![[FOOVAR:[0-9]+]] = !DILocalVariable(name: "foo",
  ; CHECK: ![[BARVAR:[0-9]+]] = !DILocalVariable(name: "bar",
  ; CHECK: ![[BAZVAR:[0-9]+]] = !DILocalVariable(name: "baz",

  ; In the following code, the:
  ;   DBG_VALUE of $edi should not sink: it's an argument
  ;   DBG_VALUE of $ebx should sink: it's a standard copy
  ;   DBG_VALUE of $bx should sink: a write of its superregister sinks
  ;   DBG_VALUE of $ecx should sink: a write of one of its subregisters sinks

  ; CHECK-LABEL: name: main
  ; CHECK: bb.0.entry:
  ; CHECK:   successors: %bb.1(0x80000000)
  ; CHECK:   liveins: $edi
  ; CHECK:   DBG_VALUE $edi, $noreg, ![[BARVAR]]
  ; CHECK-NEXT:   DBG_VALUE $edi, $noreg, ![[ARGVAR]]
  ; CHECK-NEXT:   DBG_VALUE $noreg, $noreg, ![[BAZVAR]]
  ; CHECK-NEXT:   renamable $cl = MOV8ri 1
  ; CHECK-NEXT:   DBG_VALUE $noreg, $noreg, ![[FOOVAR]]
  ; CHECK-NEXT:   JMP_1 %bb.1
  ; CHECK: bb.1.return:
  ; CHECK:   liveins: $cl, $edi
  ; CHECK:   renamable $ebx = COPY $edi
  ; CHECK-NEXT:   DBG_VALUE $bx, $noreg, ![[BAZVAR]]
  ; CHECK-NEXT:   DBG_VALUE $ebx, $noreg, ![[ARGVAR]]
  ; CHECK-NEXT:   renamable $ch = COPY renamable $cl
  ; CHECK-NEXT:   DBG_VALUE $ecx, $noreg, ![[FOOVAR]]
  ; CHECK-NEXT:   $rdi = MOV32ri64 0
  ; CHECK-NEXT:   $eax = MOV32r0 implicit-def dead $eflags
  ; CHECK-NEXT:   RET 0, $eax
  bb.0.entry:
    successors: %bb.1(0x40000000)
    liveins: $edi

    DBG_VALUE $edi, $noreg, !23, !DIExpression(), debug-location !100
    renamable $ebx = COPY $edi
    DBG_VALUE $ebx, $noreg, !21, !DIExpression(), debug-location !100
    DBG_VALUE $bx,  $noreg, !24, !DIExpression(), debug-location !100
    renamable $cl = MOV8ri 1, debug-location !100
    renamable $ch = COPY renamable $cl
    DBG_VALUE $ecx, $noreg, !22, !DIExpression(), debug-location !100
    JMP_1 %bb.1

  bb.1.return:
    liveins: $ebx, $ch

    $rdi = MOV32ri64 0
    $eax = MOV32r0 implicit-def dead $eflags
    RET 0, $eax

...