llvm-6502/test/DebugInfo/X86/formal_parameter.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

85 lines
4.0 KiB
LLVM

; ModuleID = 'formal_parameter.c'
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.9.0"
;
; From (clang -g -c -O1):
;
; int lookup(int* map);
; int verify(int val);
; void foo(int map)
; {
; lookup(&map);
; if (!verify(map)) { }
; }
;
; RUN: opt %s -O2 -S -o %t
; RUN: cat %t | FileCheck --check-prefix=LOWERING %s
; RUN: llc -filetype=obj %t -o - | llvm-dwarfdump -debug-dump=info - | FileCheck %s
; Test that we only emit only one DW_AT_formal_parameter "map" for this function.
; rdar://problem/14874886
;
; CHECK: DW_TAG_formal_parameter
; CHECK-NOT: DW_TAG
; CHECK: DW_AT_name {{.*}}map
; CHECK-NOT: DW_AT_name {{.*}}map
; Function Attrs: nounwind ssp uwtable
define void @foo(i32 %map) #0 {
entry:
%map.addr = alloca i32, align 4
store i32 %map, i32* %map.addr, align 4, !tbaa !15
call void @llvm.dbg.declare(metadata !{i32* %map.addr}, metadata !10, metadata !{i32 786690}), !dbg !14
%call = call i32 (i32*, ...)* bitcast (i32 (...)* @lookup to i32 (i32*, ...)*)(i32* %map.addr) #3, !dbg !19
; Ensure that all dbg intrinsics have the same scope after
; LowerDbgDeclare is finished with them.
;
; LOWERING: call void @llvm.dbg.value{{.*}}, !dbg ![[LOC:.*]]
; LOWERING: call void @llvm.dbg.value{{.*}}, !dbg ![[LOC]]
; LOWERING: call void @llvm.dbg.value{{.*}}, !dbg ![[LOC]]
%0 = load i32* %map.addr, align 4, !dbg !20, !tbaa !15
%call1 = call i32 (i32, ...)* bitcast (i32 (...)* @verify to i32 (i32, ...)*)(i32 %0) #3, !dbg !20
ret void, !dbg !22
}
; Function Attrs: nounwind readnone
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
declare i32 @lookup(...)
declare i32 @verify(...)
; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
attributes #0 = { nounwind ssp uwtable }
attributes #1 = { nounwind readnone }
attributes #3 = { nounwind }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!11, !12}
!llvm.ident = !{!13}
!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang version 3.5.0 ", i1 true, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [formal_parameter.c] [DW_LANG_C99]
!1 = metadata !{metadata !"formal_parameter.c", metadata !""}
!2 = metadata !{}
!3 = metadata !{metadata !4}
!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"foo", metadata !"foo", metadata !"", i32 1, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (i32)* @foo, null, null, metadata !9, i32 2} ; [ DW_TAG_subprogram ] [line 1] [def] [scope 2] [foo]
!5 = metadata !{i32 786473, metadata !1} ; [ DW_TAG_file_type ] [formal_parameter.c]
!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
!7 = metadata !{null, metadata !8}
!8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
!9 = metadata !{metadata !10}
!10 = metadata !{i32 786689, metadata !4, metadata !"map", metadata !5, i32 16777217, metadata !8, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [map] [line 1]
!11 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}
!12 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
!13 = metadata !{metadata !"clang version 3.5.0 "}
!14 = metadata !{i32 1, i32 0, metadata !4, null}
!15 = metadata !{metadata !16, metadata !16, i64 0}
!16 = metadata !{metadata !"int", metadata !17, i64 0}
!17 = metadata !{metadata !"omnipotent char", metadata !18, i64 0}
!18 = metadata !{metadata !"Simple C/C++ TBAA"}
!19 = metadata !{i32 3, i32 0, metadata !4, null}
!20 = metadata !{i32 4, i32 0, metadata !21, null}
!21 = metadata !{i32 786443, metadata !1, metadata !4, i32 4, i32 0, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [formal_parameter.c]
!22 = metadata !{i32 5, i32 0, metadata !4, null}