llvm/test/DebugInfo/X86/subreg.ll
Peter Collingbourne 5f220beefc 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252219 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 22:03:56 +00:00

35 lines
1.7 KiB
LLVM

; RUN: llc %s -mtriple=x86_64-pc-linux-gnu -O0 -o - | FileCheck %s
; We are testing that a value in a 16 bit register gets reported as
; being in its superregister.
; CHECK: .byte 80 # super-register DW_OP_reg0
; CHECK-NEXT: .byte 147 # DW_OP_piece
; CHECK-NEXT: .byte 2 # 2
define i16 @f(i16 signext %zzz) nounwind !dbg !1 {
entry:
call void @llvm.dbg.value(metadata i16 %zzz, i64 0, metadata !0, metadata !DIExpression()), !dbg !DILocation(scope: !1)
%conv = sext i16 %zzz to i32, !dbg !7
%conv1 = trunc i32 %conv to i16
ret i16 %conv1
}
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnone
!llvm.dbg.cu = !{!3}
!llvm.module.flags = !{!11}
!9 = !{!1}
!0 = !DILocalVariable(name: "zzz", line: 3, arg: 1, scope: !1, file: !2, type: !6)
!1 = distinct !DISubprogram(name: "f", line: 3, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 3, file: !10, scope: !2, type: !4)
!2 = !DIFile(filename: "/home/espindola/llvm/test.c", directory: "/home/espindola/tmpfs/build")
!3 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.0 ()", isOptimized: false, emissionKind: 1, file: !10, enums: !{}, retainedTypes: !{}, subprograms: !9, imports: null)
!4 = !DISubroutineType(types: !5)
!5 = !{null}
!6 = !DIBasicType(tag: DW_TAG_base_type, name: "short", size: 16, align: 16, encoding: DW_ATE_signed)
!7 = !DILocation(line: 4, column: 22, scope: !8)
!8 = distinct !DILexicalBlock(line: 3, column: 19, file: !10, scope: !1)
!10 = !DIFile(filename: "/home/espindola/llvm/test.c", directory: "/home/espindola/tmpfs/build")
!11 = !{i32 1, !"Debug Info Version", i32 3}