llvm-mirror/test/Bitcode/upgrade-subprogram.ll
Adrian Prantl fb3abba237 [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>

llvm-svn: 266446
2016-04-15 15:57:41 +00:00

18 lines
580 B
LLVM

; RUN: llvm-dis < %s.bc | FileCheck %s
; RUN: verify-uselistorder < %s.bc
; CHECK: define void @foo() !dbg [[SP:![0-9]+]]
define void @foo() {
ret void
}
!llvm.module.flags = !{!0}
!0 = !{i32 2, !"Debug Info Version", i32 3}
!llvm.dbg.cu = !{!1}
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, emissionKind: FullDebug)
!2 = !DIFile(filename: "foo.c", directory: "/path/to/dir")
; CHECK: [[SP]] = distinct !DISubprogram
!3 = distinct !DISubprogram(file: !2, scope: !2, line: 51, name: "foo", function: void ()* @foo, type: !4)
!4 = !DISubroutineType(types: !{})