llvm/test/DebugInfo/X86/processes-relocations.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

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LLVM

; RUN: llc -filetype=obj -O0 < %s -mtriple x86_64-none-linux | \
; RUN: llvm-dwarfdump - 2>&1 | FileCheck %s
; RUN: llc -filetype=obj -O0 < %s -mtriple i386-none-linux | \
; RUN: llvm-dwarfdump - 2>&1 | FileCheck %s
; RUN: llc -filetype=obj -O0 < %s -mtriple x86_64-none-mingw32 | \
; RUN: llvm-dwarfdump - 2>&1 | FileCheck %s
; RUN: llc -filetype=obj -O0 < %s -mtriple i386-none-mingw32 | \
; RUN: llvm-dwarfdump - 2>&1 | FileCheck %s
; CHECK-NOT: failed to compute relocation
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4}
!llvm.ident = !{!5}
!0 = distinct !DICompileUnit(file: !1, language: DW_LANG_C99, producer: "clang version 3.6.0 ", isOptimized: false, enums: !2, retainedTypes: !2, globals: !2, imports: !2, emissionKind: FullDebug)
!1 = !DIFile(filename: "empty.c", directory: "/a")
!2 = !{}
!3 = !{i32 2, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{!"clang version 3.6.0 "}