llvm/test/DebugInfo/X86/dbg-declare.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

56 lines
2.7 KiB
LLVM

; RUN: llc < %s -O0 -mtriple x86_64-apple-darwin
; <rdar://problem/11134152>
define i32 @foo(i32* %x) nounwind uwtable ssp !dbg !5 {
entry:
%x.addr = alloca i32*, align 8
%saved_stack = alloca i8*
%cleanup.dest.slot = alloca i32
store i32* %x, i32** %x.addr, align 8
call void @llvm.dbg.declare(metadata i32** %x.addr, metadata !14, metadata !DIExpression()), !dbg !15
%0 = load i32*, i32** %x.addr, align 8, !dbg !16
%1 = load i32, i32* %0, align 4, !dbg !16
%2 = zext i32 %1 to i64, !dbg !16
%3 = call i8* @llvm.stacksave(), !dbg !16
store i8* %3, i8** %saved_stack, !dbg !16
%vla = alloca i8, i64 %2, align 16, !dbg !16
call void @llvm.dbg.declare(metadata i8* %vla, metadata !18, metadata !DIExpression()), !dbg !23
store i32 1, i32* %cleanup.dest.slot
%4 = load i8*, i8** %saved_stack, !dbg !24
call void @llvm.stackrestore(i8* %4), !dbg !24
ret i32 0, !dbg !25
}
declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
declare i8* @llvm.stacksave() nounwind
declare void @llvm.stackrestore(i8*) nounwind
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!27}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.1 (trunk 153698)", isOptimized: false, emissionKind: FullDebug, file: !26, enums: !1, retainedTypes: !1, globals: !1)
!1 = !{}
!5 = distinct !DISubprogram(name: "foo", line: 6, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, file: !26, scope: !0, type: !7)
!6 = !DIFile(filename: "20020104-2.c", directory: "/Volumes/Sandbox/llvm")
!7 = !DISubroutineType(types: !8)
!8 = !{!9, !10}
!9 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
!10 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, baseType: !11)
!11 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !9)
!14 = !DILocalVariable(name: "x", line: 5, arg: 1, scope: !5, file: !6, type: !10)
!15 = !DILocation(line: 5, column: 21, scope: !5)
!16 = !DILocation(line: 7, column: 13, scope: !17)
!17 = distinct !DILexicalBlock(line: 6, column: 1, file: !26, scope: !5)
!18 = !DILocalVariable(name: "a", line: 7, scope: !17, file: !6, type: !19)
!19 = !DICompositeType(tag: DW_TAG_array_type, align: 8, baseType: !20, elements: !21)
!20 = !DIBasicType(tag: DW_TAG_base_type, name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
!21 = !{!22}
!22 = !DISubrange(count: -1)
!23 = !DILocation(line: 7, column: 8, scope: !17)
!24 = !DILocation(line: 9, column: 1, scope: !17)
!25 = !DILocation(line: 8, column: 3, scope: !17)
!26 = !DIFile(filename: "20020104-2.c", directory: "/Volumes/Sandbox/llvm")
!27 = !{i32 1, !"Debug Info Version", i32 3}