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/CodeGen/ARM/debug-info-arg.ll b/llvm/test/CodeGen/ARM/debug-info-arg.ll
index d9fa967..02bd585 100644
--- a/llvm/test/CodeGen/ARM/debug-info-arg.ll
+++ b/llvm/test/CodeGen/ARM/debug-info-arg.ll
@@ -6,7 +6,7 @@
%struct.tag_s = type { i32, i32, i32 }
-define void @foo(%struct.tag_s* nocapture %this, %struct.tag_s* %c, i64 %x, i64 %y, %struct.tag_s* nocapture %ptr1, %struct.tag_s* nocapture %ptr2) nounwind ssp {
+define void @foo(%struct.tag_s* nocapture %this, %struct.tag_s* %c, i64 %x, i64 %y, %struct.tag_s* nocapture %ptr1, %struct.tag_s* nocapture %ptr2) nounwind ssp !dbg !1 {
tail call void @llvm.dbg.value(metadata %struct.tag_s* %this, i64 0, metadata !5, metadata !DIExpression()), !dbg !20
tail call void @llvm.dbg.value(metadata %struct.tag_s* %c, i64 0, metadata !13, metadata !DIExpression()), !dbg !21
tail call void @llvm.dbg.value(metadata i64 %x, i64 0, metadata !14, metadata !DIExpression()), !dbg !22
@@ -33,7 +33,7 @@
!llvm.module.flags = !{!33}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "Apple clang version 3.0 (tags/Apple/clang-211.10.1) (based on LLVM 3.0svn)", isOptimized: true, emissionKind: 1, file: !32, enums: !{}, retainedTypes: !{}, subprograms: !30, imports: null)
-!1 = distinct !DISubprogram(name: "foo", line: 11, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 11, file: !2, scope: !2, type: !3, function: void (%struct.tag_s*, %struct.tag_s*, i64, i64, %struct.tag_s*, %struct.tag_s*)* @foo, variables: !31)
+!1 = distinct !DISubprogram(name: "foo", line: 11, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 11, file: !2, scope: !2, type: !3, variables: !31)
!2 = !DIFile(filename: "one.c", directory: "/Volumes/Athwagate/R10048772")
!3 = !DISubroutineType(types: !4)
!4 = !{null}