DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.
For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.
This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.
Since this is an IR change, a bitcode upgrade has been provided.
Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.
Differential Revision: http://reviews.llvm.org/D14265
llvm-svn: 252219
diff --git a/llvm/test/DebugInfo/X86/inline-member-function.ll b/llvm/test/DebugInfo/X86/inline-member-function.ll
index 3a1d757..712a20c 100644
--- a/llvm/test/DebugInfo/X86/inline-member-function.ll
+++ b/llvm/test/DebugInfo/X86/inline-member-function.ll
@@ -37,7 +37,7 @@
@i = global i32 0, align 4
; Function Attrs: uwtable
-define i32 @main() #0 {
+define i32 @main() #0 !dbg !13 {
entry:
%this.addr.i = alloca %struct.foo*, align 8
%x.addr.i = alloca i32, align 4
@@ -77,7 +77,7 @@
!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, flags: DIFlagArtificial | DIFlagObjectPointer, baseType: !"_ZTS3foo")
!12 = !{!13, !17}
-!13 = distinct !DISubprogram(name: "main", line: 7, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 7, file: !1, scope: !14, type: !15, function: i32 ()* @main, variables: !2)
+!13 = distinct !DISubprogram(name: "main", line: 7, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 7, file: !1, scope: !14, type: !15, variables: !2)
!14 = !DIFile(filename: "inline.cpp", directory: "/tmp/dbginfo")
!15 = !DISubroutineType(types: !16)
!16 = !{!9}