Files
clang-p2996/llvm/test/Transforms/AddDiscriminators/multiple.ll
Adrian Prantl 75819aedf6 [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
2016-04-15 15:57:41 +00:00

72 lines
3.0 KiB
LLVM

; RUN: opt < %s -add-discriminators -S | FileCheck %s
; Discriminator support for multiple CFG paths on the same line.
;
; void foo(int i) {
; int x;
; if (i < 10) x = i; else x = -i;
; }
;
; The two stores inside the if-then-else line must have different discriminator
; values.
define void @foo(i32 %i) #0 !dbg !4 {
entry:
%i.addr = alloca i32, align 4
%x = alloca i32, align 4
store i32 %i, i32* %i.addr, align 4
%0 = load i32, i32* %i.addr, align 4, !dbg !10
%cmp = icmp slt i32 %0, 10, !dbg !10
br i1 %cmp, label %if.then, label %if.else, !dbg !10
if.then: ; preds = %entry
%1 = load i32, i32* %i.addr, align 4, !dbg !10
; CHECK: %1 = load i32, i32* %i.addr, align 4, !dbg ![[THEN:[0-9]+]]
store i32 %1, i32* %x, align 4, !dbg !10
; CHECK: store i32 %1, i32* %x, align 4, !dbg ![[THEN]]
br label %if.end, !dbg !10
; CHECK: br label %if.end, !dbg ![[THEN]]
if.else: ; preds = %entry
%2 = load i32, i32* %i.addr, align 4, !dbg !10
; CHECK: %2 = load i32, i32* %i.addr, align 4, !dbg ![[ELSE:[0-9]+]]
%sub = sub nsw i32 0, %2, !dbg !10
; CHECK: %sub = sub nsw i32 0, %2, !dbg ![[ELSE]]
store i32 %sub, i32* %x, align 4, !dbg !10
; CHECK: store i32 %sub, i32* %x, align 4, !dbg ![[ELSE]]
br label %if.end
if.end: ; preds = %if.else, %if.then
ret void, !dbg !12
}
attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!7, !8}
!llvm.ident = !{!9}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.5 (trunk 199750) (llvm/trunk 199751)", isOptimized: false, emissionKind: NoDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
!1 = !DIFile(filename: "multiple.c", directory: ".")
!2 = !{}
!4 = distinct !DISubprogram(name: "foo", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, unit: !0, scopeLine: 1, file: !1, scope: !5, type: !6, variables: !2)
!5 = !DIFile(filename: "multiple.c", directory: ".")
!6 = !DISubroutineType(types: !{null, !13})
!13 = !DIBasicType(encoding: DW_ATE_signed, name: "int", size: 32, align: 32)
!7 = !{i32 2, !"Dwarf Version", i32 4}
!8 = !{i32 1, !"Debug Info Version", i32 3}
!9 = !{!"clang version 3.5 (trunk 199750) (llvm/trunk 199751)"}
!10 = !DILocation(line: 3, scope: !11)
!11 = distinct !DILexicalBlock(line: 3, column: 0, file: !1, scope: !4)
!12 = !DILocation(line: 4, scope: !4)
; CHECK: ![[THEN]] = !DILocation(line: 3, scope: ![[THENBLOCK:[0-9]+]])
; CHECK: ![[THENBLOCK]] = !DILexicalBlockFile(scope: ![[SCOPE:[0-9]+]],{{.*}} discriminator: 1)
; CHECK: ![[ELSE]] = !DILocation(line: 3, scope: ![[ELSEBLOCK:[0-9]+]])
; CHECK: ![[ELSEBLOCK]] = !DILexicalBlockFile(scope: ![[SCOPE]],{{.*}} discriminator: 2)