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/SafeStack/debug-loc.ll b/llvm/test/Transforms/SafeStack/debug-loc.ll
index d157ee6..57d565f 100644
--- a/llvm/test/Transforms/SafeStack/debug-loc.ll
+++ b/llvm/test/Transforms/SafeStack/debug-loc.ll
@@ -24,7 +24,7 @@
target triple = "x86_64-unknown-linux-gnu"
; Function Attrs: safestack uwtable
-define void @f() #0 {
+define void @f() #0 !dbg !4 {
entry:
%buf = alloca [100 x i32], align 16
%0 = bitcast [100 x i32]* %buf to i8*, !dbg !16
@@ -63,7 +63,7 @@
!1 = !DIFile(filename: "1.cc", directory: "/tmp")
!2 = !{}
!3 = !{!4}
-!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 4, type: !5, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, function: void ()* @f, variables: !7)
+!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 4, type: !5, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, variables: !7)
!5 = !DISubroutineType(types: !6)
!6 = !{null}
!7 = !{!8}