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/Inputs/gmlt.ll b/llvm/test/DebugInfo/Inputs/gmlt.ll
index d73fef3..b03a80b 100644
--- a/llvm/test/DebugInfo/Inputs/gmlt.ll
+++ b/llvm/test/DebugInfo/Inputs/gmlt.ll
@@ -98,26 +98,26 @@
; CHECK: .apple{{.*}} contents:
; Function Attrs: nounwind uwtable
-define void @_Z2f1v() #0 {
+define void @_Z2f1v() #0 !dbg !4 {
entry:
ret void, !dbg !13
}
; Function Attrs: nounwind uwtable
-define void @_Z2f2v() #0 section "__TEXT,__bar" {
+define void @_Z2f2v() #0 section "__TEXT,__bar" !dbg !7 {
entry:
ret void, !dbg !14
}
; Function Attrs: alwaysinline nounwind uwtable
-define void @_Z2f3v() #1 {
+define void @_Z2f3v() #1 !dbg !8 {
entry:
call void @_Z2f1v(), !dbg !15
ret void, !dbg !16
}
; Function Attrs: nounwind uwtable
-define void @_Z2f4v() #0 {
+define void @_Z2f4v() #0 !dbg !9 {
entry:
call void @_Z2f1v() #2, !dbg !17
ret void, !dbg !19
@@ -135,12 +135,12 @@
!1 = !DIFile(filename: "gmlt.cpp", directory: "/tmp/dbginfo")
!2 = !{}
!3 = !{!4, !7, !8, !9}
-!4 = distinct !DISubprogram(name: "f1", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 1, file: !1, scope: !5, type: !6, function: void ()* @_Z2f1v, variables: !2)
+!4 = distinct !DISubprogram(name: "f1", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
!5 = !DIFile(filename: "gmlt.cpp", directory: "/tmp/dbginfo")
!6 = !DISubroutineType(types: !2)
-!7 = distinct !DISubprogram(name: "f2", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 2, file: !1, scope: !5, type: !6, function: void ()* @_Z2f2v, variables: !2)
-!8 = distinct !DISubprogram(name: "f3", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 3, file: !1, scope: !5, type: !6, function: void ()* @_Z2f3v, variables: !2)
-!9 = distinct !DISubprogram(name: "f4", line: 4, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 4, file: !1, scope: !5, type: !6, function: void ()* @_Z2f4v, variables: !2)
+!7 = distinct !DISubprogram(name: "f2", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 2, file: !1, scope: !5, type: !6, variables: !2)
+!8 = distinct !DISubprogram(name: "f3", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 3, file: !1, scope: !5, type: !6, variables: !2)
+!9 = distinct !DISubprogram(name: "f4", line: 4, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 4, file: !1, scope: !5, type: !6, variables: !2)
!10 = !{i32 2, !"Dwarf Version", i32 4}
!11 = !{i32 2, !"Debug Info Version", i32 3}
!12 = !{!"clang version 3.6.0 "}