Files
llvm-project/llvm/test/DebugInfo/Generic/constant-pointers.ll
Peter Collingbourne d4bff30370 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
2015-11-05 22:03:56 +00:00

52 lines
2.6 KiB
LLVM

; REQUIRES: object-emission
; RUN: %llc_dwarf -O0 -filetype=obj %s -o - | llvm-dwarfdump -debug-dump=info - | FileCheck %s
; Ensure that pointer constants are emitted as unsigned data. Alternatively,
; these could be signless data (dataN).
; Built with Clang from:
; template <void *V, void (*F)(), int i>
; void func() {}
; template void func<nullptr, nullptr, 42>();
; CHECK: DW_TAG_subprogram
; CHECK: DW_TAG_template_value_parameter
; CHECK: DW_AT_name {{.*}} "V"
; CHECK: DW_AT_const_value [DW_FORM_udata] (0)
; CHECK: DW_TAG_template_value_parameter
; CHECK: DW_AT_name {{.*}} "F"
; CHECK: DW_AT_const_value [DW_FORM_udata] (0)
; Function Attrs: nounwind uwtable
define weak_odr void @_Z4funcILPv0ELPFvvE0ELi42EEvv() #0 !dbg !4 {
entry:
ret void, !dbg !18
}
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 = !{!15, !16}
!llvm.ident = !{!17}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: false, emissionKind: 1, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
!1 = !DIFile(filename: "constant-pointers.cpp", directory: "/tmp/dbginfo")
!2 = !{}
!3 = !{!4}
!4 = distinct !DISubprogram(name: "func<nullptr, nullptr, 42>", linkageName: "_Z4funcILPv0ELPFvvE0ELi42EEvv", line: 2, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 2, file: !1, scope: !5, type: !6, templateParams: !8, variables: !2)
!5 = !DIFile(filename: "constant-pointers.cpp", directory: "/tmp/dbginfo")
!6 = !DISubroutineType(types: !7)
!7 = !{null}
!8 = !{!9, !11, !13}
!9 = !DITemplateValueParameter(tag: DW_TAG_template_value_parameter, name: "V", type: !10, value: i8 0)
!10 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, baseType: null)
!11 = !DITemplateValueParameter(tag: DW_TAG_template_value_parameter, name: "F", type: !12, value: i8 0)
!12 = !DIDerivedType(tag: DW_TAG_pointer_type, size: 64, align: 64, baseType: !6)
!13 = !DITemplateValueParameter(tag: DW_TAG_template_value_parameter, name: "i", type: !14, value: i32 42)
!14 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
!15 = !{i32 2, !"Dwarf Version", i32 4}
!16 = !{i32 2, !"Debug Info Version", i32 3}
!17 = !{!"clang version 3.5.0 "}
!18 = !DILocation(line: 3, scope: !4)