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/generate-odr-hash.ll b/llvm/test/DebugInfo/X86/generate-odr-hash.ll
index 7f8303b..51f33e2 100644
--- a/llvm/test/DebugInfo/X86/generate-odr-hash.ll
+++ b/llvm/test/DebugInfo/X86/generate-odr-hash.ll
@@ -180,7 +180,7 @@
@llvm.global_ctors = appending global [1 x { i32, void ()* }] [{ i32, void ()* } { i32 65535, void ()* @_GLOBAL__I_a }]
; Function Attrs: nounwind uwtable
-define void @_Z3foov() #0 {
+define void @_Z3foov() #0 !dbg !22 {
entry:
%b = alloca %struct.baz, align 1
call void @llvm.dbg.declare(metadata %struct.baz* %b, metadata !46, metadata !DIExpression()), !dbg !48
@@ -190,14 +190,14 @@
; Function Attrs: nounwind readnone
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
-define internal void @__cxx_global_var_init() section ".text.startup" {
+define internal void @__cxx_global_var_init() section ".text.startup" !dbg !26 {
entry:
call void @_ZN12_GLOBAL__N_16walrusC2Ev(%"struct.<anonymous namespace>::walrus"* @w), !dbg !50
ret void, !dbg !50
}
; Function Attrs: nounwind uwtable
-define internal void @_ZN12_GLOBAL__N_16walrusC2Ev(%"struct.<anonymous namespace>::walrus"* %this) unnamed_addr #0 align 2 {
+define internal void @_ZN12_GLOBAL__N_16walrusC2Ev(%"struct.<anonymous namespace>::walrus"* %this) unnamed_addr #0 align 2 !dbg !27 {
entry:
%this.addr = alloca %"struct.<anonymous namespace>::walrus"*, align 8
store %"struct.<anonymous namespace>::walrus"* %this, %"struct.<anonymous namespace>::walrus"** %this.addr, align 8
@@ -206,7 +206,7 @@
ret void, !dbg !54
}
-define internal void @_GLOBAL__I_a() section ".text.startup" {
+define internal void @_GLOBAL__I_a() section ".text.startup" !dbg !36 {
entry:
call void @__cxx_global_var_init(), !dbg !55
ret void, !dbg !55
@@ -241,12 +241,12 @@
!19 = !DIDerivedType(tag: DW_TAG_member, name: "a", line: 33, size: 32, align: 32, file: !1, scope: !"_ZTSN6wombatUt_E", baseType: !12)
!20 = !DIDerivedType(tag: DW_TAG_member, name: "b", line: 34, size: 32, align: 32, offset: 32, file: !1, scope: !"_ZTSN6wombatUt_E", baseType: !12)
!21 = !{!22, !26, !27, !36}
-!22 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 5, file: !1, scope: !23, type: !24, function: void ()* @_Z3foov, variables: !2)
+!22 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 5, file: !1, scope: !23, type: !24, variables: !2)
!23 = !DIFile(filename: "bar.cpp", directory: "/tmp/dbginfo")
!24 = !DISubroutineType(types: !25)
!25 = !{null}
-!26 = distinct !DISubprogram(name: "__cxx_global_var_init", line: 29, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 29, file: !1, scope: !23, type: !24, function: void ()* @__cxx_global_var_init, variables: !2)
-!27 = distinct !DISubprogram(name: "walrus", linkageName: "_ZN12_GLOBAL__N_16walrusC2Ev", line: 25, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 25, file: !1, scope: !28, type: !32, function: void (%"struct.<anonymous namespace>::walrus"*)* @_ZN12_GLOBAL__N_16walrusC2Ev, declaration: !31, variables: !2)
+!26 = distinct !DISubprogram(name: "__cxx_global_var_init", line: 29, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 29, file: !1, scope: !23, type: !24, variables: !2)
+!27 = distinct !DISubprogram(name: "walrus", linkageName: "_ZN12_GLOBAL__N_16walrusC2Ev", line: 25, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 25, file: !1, scope: !28, type: !32, declaration: !31, variables: !2)
!28 = !DICompositeType(tag: DW_TAG_structure_type, name: "walrus", line: 24, size: 8, align: 8, file: !1, scope: !29, elements: !30)
!29 = !DINamespace(line: 23, file: !1, scope: null)
!30 = !{!31}
@@ -254,7 +254,7 @@
!32 = !DISubroutineType(types: !33)
!33 = !{null, !34}
!34 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, flags: DIFlagArtificial | DIFlagObjectPointer, baseType: !28)
-!36 = distinct !DISubprogram(name: "", linkageName: "_GLOBAL__I_a", line: 25, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagArtificial, isOptimized: false, scopeLine: 25, file: !1, scope: !23, type: !37, function: void ()* @_GLOBAL__I_a, variables: !2)
+!36 = distinct !DISubprogram(name: "", linkageName: "_GLOBAL__I_a", line: 25, isLocal: true, isDefinition: true, virtualIndex: 6, flags: DIFlagArtificial, isOptimized: false, scopeLine: 25, file: !1, scope: !23, type: !37, variables: !2)
!37 = !DISubroutineType(types: !2)
!38 = !{!39, !40, !41, !42}
!39 = !DIGlobalVariable(name: "b", line: 3, isLocal: false, isDefinition: true, scope: null, file: !23, type: !4, variable: %struct.bar* @b)