llvm/test/Transforms/InstCombine/debuginfo.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

59 lines
3.2 KiB
LLVM

; RUN: opt < %s -instcombine -S | FileCheck %s
declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
declare i64 @llvm.objectsize.i64.p0i8(i8*, i1) nounwind readnone
declare i8* @foo(i8*, i32, i64, i64) nounwind
define hidden i8* @foobar(i8* %__dest, i32 %__val, i64 %__len) nounwind inlinehint ssp !dbg !1 {
entry:
%__dest.addr = alloca i8*, align 8
%__val.addr = alloca i32, align 4
%__len.addr = alloca i64, align 8
store i8* %__dest, i8** %__dest.addr, align 8
; CHECK-NOT: call void @llvm.dbg.declare
; CHECK: call void @llvm.dbg.value
call void @llvm.dbg.declare(metadata i8** %__dest.addr, metadata !0, metadata !DIExpression()), !dbg !16
store i32 %__val, i32* %__val.addr, align 4
call void @llvm.dbg.declare(metadata i32* %__val.addr, metadata !7, metadata !DIExpression()), !dbg !18
store i64 %__len, i64* %__len.addr, align 8
call void @llvm.dbg.declare(metadata i64* %__len.addr, metadata !9, metadata !DIExpression()), !dbg !20
%tmp = load i8*, i8** %__dest.addr, align 8, !dbg !21
%tmp1 = load i32, i32* %__val.addr, align 4, !dbg !21
%tmp2 = load i64, i64* %__len.addr, align 8, !dbg !21
%tmp3 = load i8*, i8** %__dest.addr, align 8, !dbg !21
%0 = call i64 @llvm.objectsize.i64.p0i8(i8* %tmp3, i1 false), !dbg !21
%call = call i8* @foo(i8* %tmp, i32 %tmp1, i64 %tmp2, i64 %0), !dbg !21
ret i8* %call, !dbg !21
}
!llvm.dbg.cu = !{!3}
!llvm.module.flags = !{!30}
!0 = !DILocalVariable(name: "__dest", line: 78, arg: 1, scope: !1, file: !2, type: !6)
!1 = distinct !DISubprogram(name: "foobar", line: 79, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !3, scopeLine: 79, file: !27, scope: !2, type: !4, variables: !25)
!2 = !DIFile(filename: "string.h", directory: "Game")
!3 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.0 (trunk 127710)", isOptimized: true, emissionKind: FullDebug, file: !28, enums: !29, retainedTypes: !29)
!4 = !DISubroutineType(types: !5)
!5 = !{!6}
!6 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, scope: !3, baseType: null)
!7 = !DILocalVariable(name: "__val", line: 78, arg: 2, scope: !1, file: !2, type: !8)
!8 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
!9 = !DILocalVariable(name: "__len", line: 78, arg: 3, scope: !1, file: !2, type: !10)
!10 = !DIDerivedType(tag: DW_TAG_typedef, name: "size_t", line: 80, file: !27, scope: !3, baseType: !11)
!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "__darwin_size_t", line: 90, file: !27, scope: !3, baseType: !12)
!12 = !DIBasicType(tag: DW_TAG_base_type, name: "long unsigned int", size: 64, align: 64, encoding: DW_ATE_unsigned)
!16 = !DILocation(line: 78, column: 28, scope: !1)
!18 = !DILocation(line: 78, column: 40, scope: !1)
!20 = !DILocation(line: 78, column: 54, scope: !1)
!21 = !DILocation(line: 80, column: 3, scope: !22)
!22 = distinct !DILexicalBlock(line: 80, column: 3, file: !27, scope: !23)
!23 = distinct !DILexicalBlock(line: 79, column: 1, file: !27, scope: !1)
!25 = !{!0, !7, !9}
!26 = !DIFile(filename: "bits.c", directory: "Game")
!27 = !DIFile(filename: "string.h", directory: "Game")
!28 = !DIFile(filename: "bits.c", directory: "Game")
!29 = !{}
!30 = !{i32 1, !"Debug Info Version", i32 3}