llvm/test/Bitcode/debug-loc-again.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

37 lines
1.1 KiB
LLVM

; RUN: llvm-as < %s | llvm-bcanalyzer -dump | FileCheck %s -check-prefix=BC
; PR23436: Actually emit DEBUG_LOC_AGAIN records.
; BC: <DEBUG_LOC op
; BC: <DEBUG_LOC_AGAIN/>
; BC: <DEBUG_LOC op
; BC: <DEBUG_LOC_AGAIN/>
; RUN: llvm-as < %s | llvm-dis | FileCheck %s
; RUN: verify-uselistorder %s
; Check that this round-trips correctly.
define void @foo() {
entry:
%a = add i32 0, 0, !dbg !3
%b = add i32 0, 1, !dbg !3
%c = add i32 0, 2, !dbg !4
ret void, !dbg !4
}
; CHECK-LABEL: entry:
; CHECK-NEXT: %a = add i32 0, 0, !dbg ![[LINE1:[0-9]+]]
; CHECK-NEXT: %b = add i32 0, 1, !dbg ![[LINE1]]
; CHECK-NEXT: %c = add i32 0, 2, !dbg ![[LINE2:[0-9]+]]
; CHECK-NEXT: ret void, !dbg ![[LINE2]]
; CHECK: ![[LINE1]] = !DILocation(line: 1,
; CHECK: ![[LINE2]] = !DILocation(line: 2,
!llvm.module.flags = !{!0}
!llvm.dbg.cu = !{!1}
!0 = !{i32 2, !"Debug Info Version", i32 3}
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !DIFile(filename: "f", directory: "/d"))
!2 = distinct !DISubprogram(name: "foo", unit: !1)
!3 = !DILocation(line: 1, scope: !2)
!4 = !DILocation(line: 2, scope: !2)