llvm/test/CodeGen/X86/2010-01-18-DbgValue.ll
Adrian Prantl 4eeaa0da04 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266446 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-15 15:57:41 +00:00

55 lines
3.2 KiB
LLVM

; RUN: llc -march=x86 -O0 < %s | FileCheck %s
; Currently, dbg.declare generates a DEBUG_VALUE comment. Eventually it will
; generate DWARF and this test will need to be modified or removed.
%struct.Pt = type { double, double }
%struct.Rect = type { %struct.Pt, %struct.Pt }
define double @foo(%struct.Rect* byval %my_r0) nounwind ssp !dbg !1 {
entry:
;CHECK: DEBUG_VALUE
%retval = alloca double ; <double*> [#uses=2]
%0 = alloca double ; <double*> [#uses=2]
%"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0]
call void @llvm.dbg.declare(metadata %struct.Rect* %my_r0, metadata !0, metadata !DIExpression()), !dbg !15
%1 = getelementptr inbounds %struct.Rect, %struct.Rect* %my_r0, i32 0, i32 0, !dbg !16 ; <%struct.Pt*> [#uses=1]
%2 = getelementptr inbounds %struct.Pt, %struct.Pt* %1, i32 0, i32 0, !dbg !16 ; <double*> [#uses=1]
%3 = load double, double* %2, align 8, !dbg !16 ; <double> [#uses=1]
store double %3, double* %0, align 8, !dbg !16
%4 = load double, double* %0, align 8, !dbg !16 ; <double> [#uses=1]
store double %4, double* %retval, align 8, !dbg !16
br label %return, !dbg !16
return: ; preds = %entry
%retval1 = load double, double* %retval, !dbg !16 ; <double> [#uses=1]
ret double %retval1, !dbg !16
}
declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
!llvm.dbg.cu = !{!3}
!llvm.module.flags = !{!21}
!0 = !DILocalVariable(name: "my_r0", line: 11, arg: 1, scope: !1, file: !2, type: !7)
!1 = distinct !DISubprogram(name: "foo", linkageName: "foo", line: 11, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !3, scopeLine: 11, file: !19, scope: !2, type: !4)
!2 = !DIFile(filename: "b2.c", directory: "/tmp/")
!3 = distinct !DICompileUnit(language: DW_LANG_C89, producer: "4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", isOptimized: false, emissionKind: FullDebug, file: !19, enums: !20, retainedTypes: !20)
!4 = !DISubroutineType(types: !5)
!5 = !{!6, !7}
!6 = !DIBasicType(tag: DW_TAG_base_type, name: "double", size: 64, align: 64, encoding: DW_ATE_float)
!7 = !DICompositeType(tag: DW_TAG_structure_type, name: "Rect", line: 6, size: 256, align: 64, file: !19, scope: !2, elements: !8)
!8 = !{!9, !14}
!9 = !DIDerivedType(tag: DW_TAG_member, name: "P1", line: 7, size: 128, align: 64, file: !19, scope: !7, baseType: !10)
!10 = !DICompositeType(tag: DW_TAG_structure_type, name: "Pt", line: 1, size: 128, align: 64, file: !19, scope: !2, elements: !11)
!11 = !{!12, !13}
!12 = !DIDerivedType(tag: DW_TAG_member, name: "x", line: 2, size: 64, align: 64, file: !19, scope: !10, baseType: !6)
!13 = !DIDerivedType(tag: DW_TAG_member, name: "y", line: 3, size: 64, align: 64, offset: 64, file: !19, scope: !10, baseType: !6)
!14 = !DIDerivedType(tag: DW_TAG_member, name: "P2", line: 8, size: 128, align: 64, offset: 128, file: !19, scope: !7, baseType: !10)
!15 = !DILocation(line: 11, scope: !1)
!16 = !DILocation(line: 12, scope: !17)
!17 = distinct !DILexicalBlock(line: 11, column: 0, file: !19, scope: !1)
!19 = !DIFile(filename: "b2.c", directory: "/tmp/")
!20 = !{}
!21 = !{i32 1, !"Debug Info Version", i32 3}