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/Transforms/LoopVectorize/dbg.value.ll b/llvm/test/Transforms/LoopVectorize/dbg.value.ll
index ae949b3..f68b686 100644
--- a/llvm/test/Transforms/LoopVectorize/dbg.value.ll
+++ b/llvm/test/Transforms/LoopVectorize/dbg.value.ll
@@ -9,7 +9,7 @@
@C = global [1024 x i32] zeroinitializer, align 16
; CHECK-LABEL: @test(
-define i32 @test() #0 {
+define i32 @test() #0 !dbg !3 {
entry:
tail call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !9, metadata !DIExpression()), !dbg !18
br label %for.body, !dbg !18
@@ -47,7 +47,7 @@
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang", isOptimized: true, emissionKind: 0, file: !25, enums: !1, retainedTypes: !1, subprograms: !2, globals: !11)
!1 = !{}
!2 = !{!3}
-!3 = distinct !DISubprogram(name: "test", linkageName: "test", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 5, file: !25, scope: !4, type: !5, function: i32 ()* @test, variables: !8)
+!3 = distinct !DISubprogram(name: "test", linkageName: "test", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 5, file: !25, scope: !4, type: !5, variables: !8)
!4 = !DIFile(filename: "test", directory: "/path/to/somewhere")
!5 = !DISubroutineType(types: !6)
!6 = !{!7}