live-debug-values-constprop.mir 10.9 KB
# RUN: llc %s -o - -run-pass=livedebugvalues -mtriple=x86_64-unknown-unknown | FileCheck %s --check-prefix=CHECK
# RUN: llc %s -o - -start-before=livedebugvalues -filetype=obj -mtriple=x86_64-unknown-unknown | llvm-dwarfdump - | FileCheck %s --check-prefix=RANGES
# Check that livedebugvalues does the right thing when register and constant
# DBG_VALUEs interact, and that their ranges are correctly terminated by the
# debug printing backend.
--- |
  ; All these IR functions are duds, see the MIR below.
  source_filename = "<stdin>"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  
  define i32 @foo(i32* %bees, i32* %output) !dbg !4 {
  entry:
    br i1 undef, label %bb1, label %bb1
  bb1:
    br label %bb3
  bb2:
    br label %bb3
  bb3:
    ret i32 0
  }

  define i32 @bar(i32* %bees, i32* %output) !dbg !40 {
  entry:
    br i1 undef, label %bb1, label %bb1
  bb1:
    br label %bb3
  bb2:
    br label %bb3
  bb3:
    ret i32 0
  }

  define i32 @baz(i32* %bees, i32* %output) !dbg !80 {
  entry:
    br i1 undef, label %bb1, label %bb1
  bb1:
    br label %bb3
  bb2:
    br label %bb3
  bb3:
    ret i32 0
  }

  define i32 @qux(i32* %bees, i32* %output) !dbg !120 {
  entry:
    br i1 undef, label %bb1, label %bb1
  bb1:
    br label %bb3
  bb2:
    br label %bb3
  bb3:
    ret i32 0
  }

  ; Function Attrs: nounwind readnone speculatable
  declare void @llvm.dbg.value(metadata, metadata, metadata)
  
  ; Function Attrs: nounwind readnone speculatable
  declare void @llvm.dbg.declare(metadata, metadata, metadata)
  
  ; Function Attrs: nounwind
  declare void @llvm.stackprotector(i8*, i8**)
  
  !llvm.module.flags = !{!0, !100}
  !llvm.dbg.cu = !{!1}
  
  !100 = !{i32 2, !"Dwarf Version", i32 4}
  !0 = !{i32 2, !"Debug Info Version", i32 3}
  !1 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !2, producer: "beards", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
  !2 = !DIFile(filename: "bees.cpp", directory: ".")
  !3 = !DILocalVariable(name: "flannel", scope: !4, file: !2, line: 1, type: !16)
  !4 = distinct !DISubprogram(name: "nope", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
  !5 = !DILocation(line: 0, scope: !4)
  !6 = !DILocation(line: 1, scope: !4)
  !7 = !DILocation(line: 2, scope: !4)
  !8 = !DILocation(line: 4, scope: !4)
  !9 = !DILocation(line: 5, scope: !4)
  !10 = !DILocation(line: 6, scope: !4)
  !11 = !DILocation(line: 7, scope: !4)
  !12 = !DILocation(line: 8, scope: !4)
  !13 = !{!3}
  !14 = !DISubroutineType(types: !15)
  !15 = !{!16}
  !16 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
  !40 = distinct !DISubprogram(name: "bar", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
  !41 = !DILocalVariable(name: "towel", scope: !40, file: !2, line: 1, type: !16)
  !42 = !DILocation(line: 40, scope: !40)
  !80 = distinct !DISubprogram(name: "baz", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
  !81 = !DILocalVariable(name: "socks", scope: !80, file: !2, line: 1, type: !16)
  !82 = !DILocation(line: 40, scope: !80)
  !120 = distinct !DISubprogram(name: "qux", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
  !121 = !DILocalVariable(name: "shoes", scope: !120, file: !2, line: 1, type: !16)
  !122 = !DILocation(line: 40, scope: !120)

...
---
name:            foo
alignment:       16
tracksRegLiveness: true
registers:       []
liveins:         
  - { reg: '$rdi', virtual-reg: '' }
body:             |

  ; Two DBG_VALUEs for eax merge into bb3, check that livedebugvalues propagates
  ; the location.
  ; CHECK-LABEL: name: foo
  ; CHECK-LABEL: bb.1.bb1
  ; CHECK:       $eax = MOV32rr
  ; CHECK-NEXT:  DBG_VALUE $eax
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.2.bb2
  ; CHECK:       $eax = ADD32ri8
  ; CHECK-NEXT:  DBG_VALUE $eax
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.3.bb3
  ; CHECK:       DBG_VALUE $eax
  ; Test for there being a location-list gap between bb1 and bb2, as the
  ; variable does not have a location over the ADD32ri. The range should also
  ; extend over the final bb.
  ; RANGES-LABEL: DW_TAG_subprogram
  ; RANGES:       DW_AT_high_pc (0x[[NOPEHIGHPC:[0-9a-f]+]])
  ; RANGES-LABEL: DW_AT_name ("nope")
  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[NOPEADDR:[0-9a-f]+]]): DW_OP_reg0 RAX
  ; RANGES-NEXT:   [
  ; RANGES-NOT:    0x[[NOPEADDR]]
  ; RANGES-SAME:   , 0x[[NOPEHIGHPC]]): DW_OP_reg0 RAX

  bb.0.entry:
    successors: %bb.1, %bb.2
    liveins: $rdi
  
    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
    JCC_1 %bb.1, 2, implicit killed $eflags
    JMP_1 %bb.2
  
  bb.1.bb1 (align 4):
    successors: %bb.3
    liveins: $ecx, $rdi
  
    $eax = MOV32rr killed $ecx, implicit-def $rax
    DBG_VALUE $eax, $noreg, !3, !DIExpression(), debug-location !8
    JMP_1 %bb.3
  
  bb.2.bb2:
    successors: %bb.3
    liveins: $rax
  
    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
    DBG_VALUE $eax, $noreg, !3, !DIExpression(), debug-location !8
    JMP_1 %bb.3

  bb.3.bb3:
    liveins: $rax
    RETQ $eax, debug-location !9

...
---
name:            bar
alignment:       16
tracksRegLiveness: true
registers:       []
liveins:         
  - { reg: '$rdi', virtual-reg: '' }
body:             |
  ; Two DBG_VALUEs, one for eax, the other for zero, merge into bb3. Check that
  ; livedebugvalues does not propagate anything.
  ; the location.
  ; CHECK-LABEL: name: bar
  ; CHECK-LABEL: bb.1.bb1
  ; CHECK:       $eax = MOV32rr
  ; CHECK-NEXT:  DBG_VALUE 0
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.2.bb2
  ; CHECK:       $eax = ADD32ri8
  ; CHECK-NEXT:  DBG_VALUE $eax
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.3.bb3
  ; CHECK-NOT:   DBG_VALUE
  ; Test for there being a location-list gap between bb1 and bb2, the variable
  ; should not have a location over the ADD32ri. The range of the last entry
  ; should not cover the last block.
  ; RANGES-LABEL: DW_TAG_subprogram
  ; RANGES:       DW_AT_high_pc (0x[[BARHIGHPC:[0-9a-f]+]])
  ; RANGES-LABEL: DW_AT_name ("bar")
  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[BARADDR:[0-9a-f]+]]): DW_OP_consts +0, DW_OP_stack_value
  ; RANGES-NEXT:   [
  ; RANGES-NOT:    0x[[BARADDR]]
  ; RANGES-NOT:    0x[[BARHIGHPC]]
  ; RANGES-SAME:   ): DW_OP_reg0 RAX

  bb.0.entry:
    successors: %bb.1, %bb.2
    liveins: $rdi
  
    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
    JCC_1 %bb.1, 2, implicit killed $eflags
    JMP_1 %bb.2
  
  bb.1.bb1 (align 4):
    successors: %bb.3
    liveins: $ecx, $rdi
  
    $eax = MOV32rr killed $ecx, implicit-def $rax
    DBG_VALUE 0, $noreg, !41, !DIExpression(), debug-location !42
    JMP_1 %bb.3
  
  bb.2.bb2:
    successors: %bb.3
    liveins: $rax
  
    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
    DBG_VALUE $eax, $noreg, !41, !DIExpression(), debug-location !42
    JMP_1 %bb.3

  bb.3.bb3:
    liveins: $rax
    RETQ $eax, debug-location !42

...
---
name:            baz
alignment:       16
tracksRegLiveness: true
registers:       []
liveins:         
  - { reg: '$rdi', virtual-reg: '' }
body:             |
  ; Two DBG_VALUEs, one for zero, the other for eax, merge into bb3. Check that
  ; livedebugvalues does not propagate anything.
  ; the location.
  ; CHECK-LABEL: name: baz
  ; CHECK-LABEL: bb.1.bb1
  ; CHECK:       $eax = MOV32rr
  ; CHECK-NEXT:  DBG_VALUE $eax
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.2.bb2
  ; CHECK:       $eax = ADD32ri8
  ; CHECK-NEXT:  DBG_VALUE 0
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.3.bb3
  ; CHECK-NOT:   DBG_VALUE
  ; Test for there being a location-list gap between bb1 and bb2, the variable
  ; should not have a location over the ADD32ri. The range of the last item
  ; should not cover the last block.
  ; RANGES-LABEL: DW_TAG_subprogram
  ; RANGES:       DW_AT_high_pc (0x[[BAZHIGHPC:[0-9a-f]+]])
  ; RANGES-LABEL: DW_AT_name ("baz")
  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[BAZADDR:[0-9a-f]+]]): DW_OP_reg0 RAX
  ; RANGES-NEXT:   [
  ; RANGES-NOT:    0x[[BAZADDR]]
  ; RANGES-NOT:    0x[[BAZHIGHPC]]
  ; RANGES-SAME:   ): DW_OP_consts +0, DW_OP_stack_value

  bb.0.entry:
    successors: %bb.1, %bb.2
    liveins: $rdi
  
    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
    JCC_1 %bb.1, 2, implicit killed $eflags
    JMP_1 %bb.2
  
  bb.1.bb1 (align 4):
    successors: %bb.3
    liveins: $ecx, $rdi
  
    $eax = MOV32rr killed $ecx, implicit-def $rax
    DBG_VALUE $eax, $noreg, !81, !DIExpression(), debug-location !82
    JMP_1 %bb.3
  
  bb.2.bb2:
    successors: %bb.3
    liveins: $rax
  
    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
    DBG_VALUE 0, $noreg, !81, !DIExpression(), debug-location !82
    JMP_1 %bb.3

  bb.3.bb3:
    liveins: $rax
    RETQ $eax, debug-location !82

...
---
name:            qux
alignment:       16
tracksRegLiveness: true
registers:       []
liveins:         
  - { reg: '$rdi', virtual-reg: '' }
body:             |
  ; Two DBG_VALUEs for zero merging into bb3, Check that livedebugvalues does
  ; propagate the zero into the merging block.
  ; CHECK-LABEL: name: qux
  ; CHECK-LABEL: bb.1.bb1
  ; CHECK:       $eax = MOV32rr
  ; CHECK-NEXT:  DBG_VALUE 0
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.2.bb2
  ; CHECK:       $eax = ADD32ri8
  ; CHECK-NEXT:  DBG_VALUE 0
  ; CHECK-NEXT:  JMP_1 %bb.3
  ; CHECK-LABEL: bb.3.bb3
  ; CHECK:       DBG_VALUE 0
  ; Test for there being a location-list gap between bb1 and bb2, the variable
  ; should not have a location over the ADD32ri. The final entry should cover
  ; the final block.
  ; RANGES-LABEL: DW_TAG_subprogram
  ; RANGES:       DW_AT_high_pc (0x[[QUXHIGHPC:[0-9a-f]+]])
  ; RANGES-LABEL: DW_AT_name ("qux")
  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[QUXADDR:[0-9a-f]+]]): DW_OP_consts +0, DW_OP_stack_value
  ; RANGES-NOT:    0x[[QUXADDR]]
  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[QUXHIGHPC]]): DW_OP_consts +0, DW_OP_stack_value

  bb.0.entry:
    successors: %bb.1, %bb.2
    liveins: $rdi
  
    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
    JCC_1 %bb.1, 2, implicit killed $eflags
    JMP_1 %bb.2
  
  bb.1.bb1 (align 4):
    successors: %bb.3
    liveins: $ecx, $rdi
  
    $eax = MOV32rr killed $ecx, implicit-def $rax
    DBG_VALUE 0, $noreg, !121, !DIExpression(), debug-location !122
    JMP_1 %bb.3
  
  bb.2.bb2:
    successors: %bb.3
    liveins: $rax
  
    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
    DBG_VALUE 0, $noreg, !121, !DIExpression(), debug-location !122
    JMP_1 %bb.3

  bb.3.bb3:
    liveins: $rax
    RETQ $eax, debug-location !122

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