llvm/test/Linker/2011-08-18-unique-class-type.ll
Adrian Prantl 02474a32eb Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

Note: I accidentally committed a bogus older version of this patch previously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218787 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-01 18:55:02 +00:00

41 lines
2.6 KiB
LLVM

; RUN: llvm-link %s %p/2011-08-18-unique-class-type2.ll -S -o - | FileCheck %s
; CHECK: DW_TAG_class_type
; CHECK-NOT: DW_TAG_class_type
; Test to check there is only one MDNode for class A after linking.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-apple-macosx10.7.0"
%"class.N1::A" = type { i8 }
define void @_Z3fooN2N11AE() nounwind uwtable ssp {
entry:
%mya = alloca %"class.N1::A", align 1
call void @llvm.dbg.declare(metadata !{%"class.N1::A"* %mya}, metadata !9, metadata !{i32 786690}), !dbg !13
ret void, !dbg !14
}
declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!18}
!0 = metadata !{i32 720913, metadata !16, i32 4, metadata !"clang version 3.0 (trunk 137954)", i1 true, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, null, metadata !""} ; [ DW_TAG_compile_unit ]
!1 = metadata !{metadata !2}
!2 = metadata !{i32 0}
!3 = metadata !{metadata !5}
!5 = metadata !{i32 720942, metadata !16, metadata !6, metadata !"foo", metadata !"foo", metadata !"_Z3fooN2N11AE", i32 4, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void ()* @_Z3fooN2N11AE, null, null, null, i32 0} ; [ DW_TAG_subprogram ] [line 4] [def] [scope 0] [foo]
!6 = metadata !{i32 720937, metadata !16} ; [ DW_TAG_file_type ]
!7 = metadata !{i32 720917, metadata !16, metadata !6, metadata !"", i32 0, i64 0, i64 0, i32 0, i32 0, null, metadata !8, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!8 = metadata !{null}
!9 = metadata !{i32 721153, metadata !5, metadata !"mya", metadata !6, i32 16777220, metadata !10, i32 0, i32 0} ; [ DW_TAG_arg_variable ]
!10 = metadata !{i32 720898, metadata !17, metadata !11, metadata !"A", i32 3, i64 8, i64 8, i32 0, i32 0, null, metadata !2, i32 0, null, null, null} ; [ DW_TAG_class_type ] [A] [line 3, size 8, align 8, offset 0] [def] [from ]
!11 = metadata !{i32 720953, metadata !17, null, metadata !"N1", i32 2} ; [ DW_TAG_namespace ]
!12 = metadata !{i32 720937, metadata !17} ; [ DW_TAG_file_type ]
!13 = metadata !{i32 4, i32 12, metadata !5, null}
!14 = metadata !{i32 4, i32 18, metadata !15, null}
!15 = metadata !{i32 720907, metadata !16, metadata !5, i32 4, i32 17, i32 0} ; [ DW_TAG_lexical_block ]
!16 = metadata !{metadata !"n1.c", metadata !"/private/tmp"}
!17 = metadata !{metadata !"./n.h", metadata !"/private/tmp"}
!18 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}