llvm/test/DebugInfo/Generic/2010-01-05-DbgScope.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

25 lines
1.1 KiB
LLVM

; RUN: llc < %s -o /dev/null
; PR 5942
define i8* @foo() nounwind {
entry:
%0 = load i32, i32* undef, align 4, !dbg !0 ; <i32> [#uses=1]
%1 = inttoptr i32 %0 to i8*, !dbg !0 ; <i8*> [#uses=1]
ret i8* %1, !dbg !10
}
!llvm.dbg.cu = !{!3}
!llvm.module.flags = !{!14}
!0 = !DILocation(line: 571, column: 3, scope: !1)
!1 = distinct !DILexicalBlock(line: 1, column: 1, file: !11, scope: !2)
!2 = distinct !DISubprogram(name: "foo", linkageName: "foo", line: 561, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: false, unit: !3, scope: !3, type: !4)
!3 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang 1.1", isOptimized: true, emissionKind: FullDebug, file: !11, enums: !12, retainedTypes: !12)
!4 = !DISubroutineType(types: !5)
!5 = !{!6}
!6 = !DIBasicType(tag: DW_TAG_base_type, name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
!10 = !DILocation(line: 588, column: 1, scope: !2)
!11 = !DIFile(filename: "hashtab.c", directory: "/usr/src/gnu/usr.bin/cc/cc_tools/../../../../contrib/gcclibs/libiberty")
!12 = !{}
!14 = !{i32 1, !"Debug Info Version", i32 3}