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/SampleProfile/branch.ll b/llvm/test/Transforms/SampleProfile/branch.ll
index 9ee124b..1700749 100644
--- a/llvm/test/Transforms/SampleProfile/branch.ll
+++ b/llvm/test/Transforms/SampleProfile/branch.ll
@@ -28,7 +28,7 @@
@.str = private unnamed_addr constant [15 x i8] c"result is %lf\0A\00", align 1
; Function Attrs: uwtable
-define i32 @main(i32 %argc, i8** %argv) #0 {
+define i32 @main(i32 %argc, i8** %argv) #0 !dbg !6 {
; CHECK: Printing analysis 'Branch Probability Analysis' for function 'main':
entry:
@@ -163,7 +163,7 @@
!3 = !{!4}
!4 = !DIBasicType(name: "double", size: 64, align: 64, encoding: DW_ATE_float)
!5 = !{!6}
-!6 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 4, type: !7, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, function: i32 (i32, i8**)* @main, variables: !2)
+!6 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 4, type: !7, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
!7 = !DISubroutineType(types: !8)
!8 = !{!9, !9, !10}
!9 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)