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/earlydup-crash.ll b/llvm/test/DebugInfo/X86/earlydup-crash.ll
index 2028544..7362659 100644
--- a/llvm/test/DebugInfo/X86/earlydup-crash.ll
+++ b/llvm/test/DebugInfo/X86/earlydup-crash.ll
@@ -6,7 +6,7 @@
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnone
-define internal i8* @framework_construct_pathname(i8* %fname, %struct.cpp_dir* %dir) nounwind ssp {
+define internal i8* @framework_construct_pathname(i8* %fname, %struct.cpp_dir* %dir) nounwind ssp !dbg !2 {
entry:
br i1 undef, label %bb33, label %bb
@@ -46,7 +46,7 @@
!llvm.module.flags = !{!47}
!0 = !DILocalVariable(name: "frname_len", line: 517, scope: !1, file: !3, type: !38)
!1 = distinct !DILexicalBlock(line: 515, column: 0, file: !44, scope: !2)
-!2 = distinct !DISubprogram(name: "framework_construct_pathname", line: 515, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, file: !44, scope: null, type: !5, function: i8* (i8*, %struct.cpp_dir*)* @framework_construct_pathname)
+!2 = distinct !DISubprogram(name: "framework_construct_pathname", line: 515, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, file: !44, scope: null, type: !5)
!3 = !DIFile(filename: "darwin-c.c", directory: "/Users/espindola/llvm/build-llvm-gcc/gcc/../../llvm-gcc-4.2/gcc/config")
!4 = distinct !DICompileUnit(language: DW_LANG_C89, producer: "4.2.1 (Based on Apple Inc. build 5658) (LLVM build)", isOptimized: true, emissionKind: 0, file: !44, enums: !46, retainedTypes: !46, subprograms: !45)
!5 = !DISubroutineType(types: !6)