[PR27284] Reverse the ownership between DICompileUnit and DISubprogram.

Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

llvm-svn: 266446

11 files changed, 26 insertions, 36 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/X86/no_fpmath.ll b/llvm/test/Transforms/LoopVectorize/X86/no_fpmath.ll
index eee6dd83788..055d81a390b 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/no_fpmath.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/no_fpmath.ll
@@ -79,7 +79,7 @@ attributes #0 = { nounwind }
 !1 = !{i32 1, !"PIC Level", i32 2}
 !2 = !{!"clang version 3.7.0"}
 !3 = !DILocation(line: 5, column: 20, scope: !4)
-!4 = distinct !DISubprogram(name: "cond_sum", scope: !5, file: !5, line: 1, type: !6, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, variables: !7)
+!4 = distinct !DISubprogram(name: "cond_sum", scope: !5, file: !5, line: 1, type: !6, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !28, variables: !7)
 !5 = !DIFile(filename: "no_fpmath.c", directory: "")
 !6 = !DISubroutineType(types: !7)
 !7 = !{}
@@ -95,7 +95,7 @@ attributes #0 = { nounwind }
 !17 = distinct !{!17, !18}
 !18 = !{!"llvm.loop.unroll.disable"}
 !19 = !DILocation(line: 16, column: 20, scope: !20)
-!20 = distinct !DISubprogram(name: "cond_sum_loop_hint", scope: !5, file: !5, line: 12, type: !6, isLocal: false, isDefinition: true, scopeLine: 12, flags: DIFlagPrototyped, isOptimized: true, variables: !7)
+!20 = distinct !DISubprogram(name: "cond_sum_loop_hint", scope: !5, file: !5, line: 12, type: !6, isLocal: false, isDefinition: true, scopeLine: 12, flags: DIFlagPrototyped, isOptimized: true, unit: !28, variables: !7)
 !21 = !DILocation(line: 16, column: 3, scope: !20)
 !22 = !DILocation(line: 17, column: 14, scope: !20)
 !23 = !DILocation(line: 20, column: 3, scope: !20)
@@ -106,5 +106,4 @@ attributes #0 = { nounwind }
 !28 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang",
                              file: !5,
                              isOptimized: true, flags: "-O2",
-                             splitDebugFilename: "abc.debug", emissionKind: 2, 
-                             subprograms: !{!4, !20})
+                             splitDebugFilename: "abc.debug", emissionKind: 2)
diff --git a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
index 740ff3682be..419f2e02456 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-missed.ll
@@ -123,15 +123,14 @@ attributes #0 = { nounwind }
 !llvm.module.flags = !{!9, !10}
 !llvm.ident = !{!11}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, runtimeVersion: 6, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, runtimeVersion: 6, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
 !1 = !DIFile(filename: "source.cpp", directory: ".")
 !2 = !{}
-!3 = !{!4, !7, !8}
-!4 = distinct !DISubprogram(name: "test", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
+!4 = distinct !DISubprogram(name: "test", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
 !5 = !DIFile(filename: "source.cpp", directory: ".")
 !6 = !DISubroutineType(types: !2)
-!7 = distinct !DISubprogram(name: "test_disabled", line: 10, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 10, file: !1, scope: !5, type: !6, variables: !2)
-!8 = distinct !DISubprogram(name: "test_array_bounds", line: 16, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 16, file: !1, scope: !5, type: !6, variables: !2)
+!7 = distinct !DISubprogram(name: "test_disabled", line: 10, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 10, file: !1, scope: !5, type: !6, variables: !2)
+!8 = distinct !DISubprogram(name: "test_array_bounds", line: 16, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 16, file: !1, scope: !5, type: !6, variables: !2)
 !9 = !{i32 2, !"Dwarf Version", i32 2}
 !10 = !{i32 2, !"Debug Info Version", i32 3}
 !11 = !{!"clang version 3.5.0"}
diff --git a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-profitable.ll b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-profitable.ll
index 1fb2109d3dc..fc9f97328fb 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-profitable.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks-profitable.ll
@@ -82,13 +82,12 @@ attributes #0 = { nounwind uwtable "disable-tail-calls"="false" "less-precise-fp
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 250016)", isOptimized: false, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2, subprograms: !3)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 250016)", isOptimized: false, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2)
 !1 = !DIFile(filename: "vectorization-remarks-profitable.c", directory: "")
 !2 = !{}
-!3 = !{!4, !6}
-!4 = distinct !DISubprogram(name: "do_not_interleave", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!4 = distinct !DISubprogram(name: "do_not_interleave", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
 !5 = !DISubroutineType(types: !2)
-!6 = distinct !DISubprogram(name: "interleave_not_profitable", scope: !1, file: !1, line: 8, type: !5, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!6 = distinct !DISubprogram(name: "interleave_not_profitable", scope: !1, file: !1, line: 8, type: !5, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, unit: !0, variables: !2)
 !7 = !{i32 2, !"Dwarf Version", i32 4}
 !8 = !{i32 2, !"Debug Info Version", i32 3}
 !9 = !{!"clang version 3.8.0 (trunk 250016)"}
diff --git a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
index 21f3591a044..36eb172df7e 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
@@ -53,7 +53,7 @@ declare void @ibar(i32*) #1
 !1 = !DIFile(filename: "vectorization-remarks.c", directory: ".")
 !2 = !{}
 !3 = !{!4}
-!4 = distinct !DISubprogram(name: "foo", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 6, file: !1, scope: !5, type: !6, variables: !2)
+!4 = distinct !DISubprogram(name: "foo", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !24, scopeLine: 6, file: !1, scope: !5, type: !6, variables: !2)
 !5 = !DIFile(filename: "vectorization-remarks.c", directory: ".")
 !6 = !DISubroutineType(types: !2)
 !7 = !{i32 2, !"Dwarf Version", i32 4}
@@ -73,4 +73,4 @@ declare void @ibar(i32*) #1
 !21 = !{!13, !13, i64 0}
 !22 = !DILocation(line: 20, column: 3, scope: !4)
 !23 = !DILocation(line: 21, column: 3, scope: !4)
-!24 = distinct !DICompileUnit(language: DW_LANG_C89, file: !1, subprograms: !{!4})
+!24 = distinct !DICompileUnit(language: DW_LANG_C89, file: !1)
diff --git a/llvm/test/Transforms/LoopVectorize/conditional-assignment.ll b/llvm/test/Transforms/LoopVectorize/conditional-assignment.ll
index e1f0addd325..a60e8a20cd4 100644
--- a/llvm/test/Transforms/LoopVectorize/conditional-assignment.ll
+++ b/llvm/test/Transforms/LoopVectorize/conditional-assignment.ll
@@ -36,11 +36,10 @@ attributes #0 = { nounwind }
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.6.0", isOptimized: true, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.6.0", isOptimized: true, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
 !1 = !DIFile(filename: "source.c", directory: ".")
 !2 = !{}
-!3 = !{!4}
-!4 = distinct !DISubprogram(name: "conditional_store", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
+!4 = distinct !DISubprogram(name: "conditional_store", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
 !5 = !DIFile(filename: "source.c", directory: ".")
 !6 = !DISubroutineType(types: !2)
 !7 = !{i32 2, !"Dwarf Version", i32 2}
diff --git a/llvm/test/Transforms/LoopVectorize/control-flow.ll b/llvm/test/Transforms/LoopVectorize/control-flow.ll
index e769a62869c..78ce29eff52 100644
--- a/llvm/test/Transforms/LoopVectorize/control-flow.ll
+++ b/llvm/test/Transforms/LoopVectorize/control-flow.ll
@@ -55,11 +55,10 @@ attributes #0 = { nounwind }
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, runtimeVersion: 6, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, runtimeVersion: 6, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
 !1 = !DIFile(filename: "source.cpp", directory: ".")
 !2 = !{}
-!3 = !{!4}
-!4 = distinct !DISubprogram(name: "test", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 2, file: !1, scope: !5, type: !6, variables: !2)
+!4 = distinct !DISubprogram(name: "test", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 2, file: !1, scope: !5, type: !6, variables: !2)
 !5 = !DIFile(filename: "source.cpp", directory: ".")
 !6 = !DISubroutineType(types: !2)
 !7 = !{i32 2, !"Dwarf Version", i32 2}
diff --git a/llvm/test/Transforms/LoopVectorize/dbg.value.ll b/llvm/test/Transforms/LoopVectorize/dbg.value.ll
index c4ae0296349..d7d3ff6d9f9 100644
--- a/llvm/test/Transforms/LoopVectorize/dbg.value.ll
+++ b/llvm/test/Transforms/LoopVectorize/dbg.value.ll
@@ -44,10 +44,9 @@ attributes #1 = { nounwind readnone }
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!26}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang", isOptimized: true, emissionKind: FullDebug, file: !25, enums: !1, retainedTypes: !1, subprograms: !2, globals: !11)
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang", isOptimized: true, emissionKind: FullDebug, file: !25, enums: !1, retainedTypes: !1, 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, variables: !8)
+!3 = distinct !DISubprogram(name: "test", linkageName: "test", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 5, file: !25, scope: !4, type: !5, variables: !8)
 !4 = !DIFile(filename: "test", directory: "/path/to/somewhere")
 !5 = !DISubroutineType(types: !6)
 !6 = !{!7}
diff --git a/llvm/test/Transforms/LoopVectorize/debugloc.ll b/llvm/test/Transforms/LoopVectorize/debugloc.ll
index feeeb08a6ed..45cb9a2baea 100644
--- a/llvm/test/Transforms/LoopVectorize/debugloc.ll
+++ b/llvm/test/Transforms/LoopVectorize/debugloc.ll
@@ -63,11 +63,10 @@ attributes #1 = { nounwind readnone }
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!18, !27}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (trunk 185038) (llvm/trunk 185097)", isOptimized: true, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.4 (trunk 185038) (llvm/trunk 185097)", isOptimized: true, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
 !1 = !DIFile(filename: "-", directory: "/Volumes/Data/backedup/dev/os/llvm/debug")
 !2 = !{}
-!3 = !{!4}
-!4 = distinct !DISubprogram(name: "f", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 3, file: !5, scope: !6, type: !7, variables: !12)
+!4 = distinct !DISubprogram(name: "f", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 3, file: !5, scope: !6, type: !7, variables: !12)
 !5 = !DIFile(filename: "<stdin>", directory: "/Volumes/Data/backedup/dev/os/llvm/debug")
 !6 = !DIFile(filename: "<stdin>", directory: "/Volumes/Data/backedup/dev/os/llvm/debug")
 !7 = !DISubroutineType(types: !8)
diff --git a/llvm/test/Transforms/LoopVectorize/no_array_bounds.ll b/llvm/test/Transforms/LoopVectorize/no_array_bounds.ll
index 521edac22c7..44412bce27f 100644
--- a/llvm/test/Transforms/LoopVectorize/no_array_bounds.ll
+++ b/llvm/test/Transforms/LoopVectorize/no_array_bounds.ll
@@ -72,11 +72,10 @@ attributes #0 = { nounwind }
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
 !1 = !DIFile(filename: "no_array_bounds.cpp", directory: ".")
 !2 = !{}
-!3 = !{!4}
-!4 = distinct !DISubprogram(name: "test", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 2, file: !1, scope: !5, type: !6, variables: !2)
+!4 = distinct !DISubprogram(name: "test", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 2, file: !1, scope: !5, type: !6, variables: !2)
 !5 = !DIFile(filename: "no_array_bounds.cpp", directory: ".")
 !6 = !DISubroutineType(types: !2)
 !7 = !{i32 2, !"Dwarf Version", i32 2}
diff --git a/llvm/test/Transforms/LoopVectorize/no_switch.ll b/llvm/test/Transforms/LoopVectorize/no_switch.ll
index 6e7f413507b..181304a409e 100644
--- a/llvm/test/Transforms/LoopVectorize/no_switch.ll
+++ b/llvm/test/Transforms/LoopVectorize/no_switch.ll
@@ -67,11 +67,10 @@ attributes #0 = { nounwind }
 !llvm.module.flags = !{!7, !8}
 !llvm.ident = !{!9}
 
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, runtimeVersion: 6, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0", isOptimized: true, runtimeVersion: 6, emissionKind: LineTablesOnly, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
 !1 = !DIFile(filename: "source.cpp", directory: ".")
 !2 = !{}
-!3 = !{!4}
-!4 = distinct !DISubprogram(name: "test_switch", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
+!4 = distinct !DISubprogram(name: "test_switch", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
 !5 = !DIFile(filename: "source.cpp", directory: ".")
 !6 = !DISubroutineType(types: !2)
 !7 = !{i32 2, !"Dwarf Version", i32 2}
diff --git a/llvm/test/Transforms/LoopVectorize/runtime-check.ll b/llvm/test/Transforms/LoopVectorize/runtime-check.ll
index 02751e4b25c..2bd8b43820d 100644
--- a/llvm/test/Transforms/LoopVectorize/runtime-check.ll
+++ b/llvm/test/Transforms/LoopVectorize/runtime-check.ll
@@ -74,14 +74,13 @@ loopexit:
 !2 = !{}
 !3 = !DISubroutineType(types: !2)
 !4 = !DIFile(filename: "test.cpp", directory: "/tmp")
-!5 = distinct !DISubprogram(name: "foo", scope: !4, file: !4, line: 99, type: !3, isLocal: false, isDefinition: true, scopeLine: 100, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!5 = distinct !DISubprogram(name: "foo", scope: !4, file: !4, line: 99, type: !3, isLocal: false, isDefinition: true, scopeLine: 100, flags: DIFlagPrototyped, isOptimized: false, unit: !9, variables: !2)
 !6 = !DILocation(line: 100, column: 1, scope: !5)
 !7 = !DILocation(line: 101, column: 1, scope: !5)
 !8 = !DILocation(line: 102, column: 1, scope: !5)
 !9 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang",
                              file: !10,
                              isOptimized: true, flags: "-O2",
-                             splitDebugFilename: "abc.debug", emissionKind: 2,
-                             subprograms: !{!5})
+                             splitDebugFilename: "abc.debug", emissionKind: 2)
 !10 = !DIFile(filename: "path/to/file", directory: "/path/to/dir")
 !11 = !{i32 2, !"Debug Info Version", i32 3}