1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
; RUN: opt %s -S -passes=dse -o - | FileCheck %s
;; Observed in the wild, but test is created by running memcpyopt on
;; assignment-tracking/memcpyopt/merge-stores.ll then manually inserting
;; two stores that overwrite each end of the memset.
;;
;; A memory intrinsic (or vector instruction) might have multiple dbg.assigns
;; linked to it if it has been created as a result of merging scalar stores,
;; such as in this example. DSE is going to shorten the memset because there's
;; a later store that overwrites part of it. Insert a linked dbg.assign after
;; each overlapping fragment to undef the dead part's memory location without
;; needing to work out how to split the fragments exactly.
;; Check that there's an unlinked dbg.assign inserted after each overlapping
;; fragment of the shortened store.
;;
; CHECK: call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata ![[VAR:[0-9]+]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32), metadata ![[ID:[0-9]+]], metadata ptr %arrayidx5.i, metadata !DIExpression())
; CHECK-NEXT: call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata ![[VAR]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32), metadata ![[UniqueID1:[0-9]+]], metadata ptr undef, metadata !DIExpression())
; CHECK: call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata ![[VAR]], metadata !DIExpression(DW_OP_LLVM_fragment, 96, 32), metadata ![[ID]], metadata ptr %arrayidx7.i, metadata !DIExpression())
; CHECK-NEXT: call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata ![[VAR]], metadata !DIExpression(DW_OP_LLVM_fragment, 96, 32), metadata ![[UniqueID2:[0-9]+]], metadata ptr undef, metadata !DIExpression())
; CHECK: call void @llvm.memset{{.*}}, !DIAssignID ![[ID]]
; CHECK-DAG: ![[ID]] = distinct !DIAssignID()
; CHECK-DAG: ![[UniqueID1]] = distinct !DIAssignID()
; CHECK-DAG: ![[UniqueID2]] = distinct !DIAssignID()
%struct.v = type { [4 x float] }
$_ZN1vC2Ef = comdat any
define dso_local void @_Z1fv() local_unnamed_addr !dbg !7 {
entry:
%g = alloca %struct.v, align 4, !DIAssignID !23
call void @llvm.dbg.assign(metadata i1 undef, metadata !11, metadata !DIExpression(), metadata !23, metadata ptr %g, metadata !DIExpression()), !dbg !24
call void @llvm.lifetime.start.p0i8(i64 16, ptr nonnull %g), !dbg !25
call void @llvm.dbg.assign(metadata ptr %g, metadata !26, metadata !DIExpression(), metadata !35, metadata ptr undef, metadata !DIExpression()), !dbg !32
call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata !29, metadata !DIExpression(), metadata !36, metadata ptr undef, metadata !DIExpression()), !dbg !32
%arrayidx.i = getelementptr inbounds %struct.v, ptr %g, i64 0, i32 0, i64 2, !dbg !37
call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 64, 32), metadata !39, metadata ptr %arrayidx.i, metadata !DIExpression()), !dbg !24
%arrayidx3.i = getelementptr inbounds %struct.v, ptr %g, i64 0, i32 0, i64 1, !dbg !40
call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 32, 32), metadata !39, metadata ptr %arrayidx3.i, metadata !DIExpression()), !dbg !24
%arrayidx5.i = getelementptr inbounds %struct.v, ptr %g, i64 0, i32 0, i64 0, !dbg !41
call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32), metadata !39, metadata ptr %arrayidx5.i, metadata !DIExpression()), !dbg !24
%arrayidx7.i = getelementptr inbounds %struct.v, ptr %g, i64 0, i32 0, i64 3, !dbg !42
call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 96, 32), metadata !39, metadata ptr %arrayidx7.i, metadata !DIExpression()), !dbg !24
%0 = bitcast ptr %arrayidx5.i to ptr, !dbg !43
call void @llvm.memset.p0i8.i64(ptr align 4 %0, i8 0, i64 16, i1 false), !dbg !44, !DIAssignID !39
;; -- Start modification
%arrayidx7 = getelementptr inbounds %struct.v, ptr %g, i64 0, i32 0, i64 3, !dbg !24
store float 0.000000e+00, ptr %arrayidx7, align 4, !dbg !24, !DIAssignID !49
call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 96, 32), metadata !49, metadata ptr %arrayidx7, metadata !DIExpression()), !dbg !24
%arrayidx = getelementptr inbounds %struct.v, ptr %g, i64 0, i32 0, i64 0, !dbg !24
store float 0.000000e+00, ptr %arrayidx, align 4, !dbg !24, !DIAssignID !50
call void @llvm.dbg.assign(metadata float 0.000000e+00, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32), metadata !50, metadata ptr %arrayidx, metadata !DIExpression()), !dbg !24
;; -- End modification
call void @_Z3escP1v(ptr nonnull %g), !dbg !43
call void @llvm.lifetime.end.p0i8(i64 16, ptr nonnull %0), !dbg !45
ret void, !dbg !45
}
declare void @llvm.lifetime.start.p0i8(i64 immarg, ptr nocapture)
declare !dbg !64 dso_local void @_Z3escP1v(ptr) local_unnamed_addr
declare void @llvm.lifetime.end.p0i8(i64 immarg, ptr nocapture)
declare void @llvm.dbg.assign(metadata, metadata, metadata, metadata, metadata, metadata)
declare void @llvm.memset.p0i8.i64(ptr nocapture writeonly, i8, i64, i1 immarg)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5, !1000}
!llvm.ident = !{!6}
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 12.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "reduce.cpp", directory: "/")
!2 = !{}
!3 = !{i32 7, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 4}
!6 = !{!"clang version 12.0.0"}
!7 = distinct !DISubprogram(name: "f", linkageName: "_Z1fv", scope: !1, file: !1, line: 12, type: !8, scopeLine: 12, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
!8 = !DISubroutineType(types: !9)
!9 = !{null}
!10 = !{!11}
!11 = !DILocalVariable(name: "g", scope: !7, file: !1, line: 13, type: !12)
!12 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "v", file: !1, line: 1, size: 128, flags: DIFlagTypePassByValue | DIFlagNonTrivial, elements: !13, identifier: "_ZTS1v")
!13 = !{!14, !19}
!14 = !DIDerivedType(tag: DW_TAG_member, name: "c", scope: !12, file: !1, line: 2, baseType: !15, size: 128)
!15 = !DICompositeType(tag: DW_TAG_array_type, baseType: !16, size: 128, elements: !17)
!16 = !DIBasicType(name: "float", size: 32, encoding: DW_ATE_float)
!17 = !{!18}
!18 = !DISubrange(count: 4)
!19 = !DISubprogram(name: "v", scope: !12, file: !1, line: 4, type: !20, scopeLine: 4, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
!20 = !DISubroutineType(types: !21)
!21 = !{null, !22, !16}
!22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
!23 = distinct !DIAssignID()
!24 = !DILocation(line: 0, scope: !7)
!25 = !DILocation(line: 13, column: 3, scope: !7)
!26 = !DILocalVariable(name: "this", arg: 1, scope: !27, type: !30, flags: DIFlagArtificial | DIFlagObjectPointer)
!27 = distinct !DISubprogram(name: "v", linkageName: "_ZN1vC2Ef", scope: !12, file: !1, line: 4, type: !20, scopeLine: 4, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, declaration: !19, retainedNodes: !28)
!28 = !{!26, !29}
!29 = !DILocalVariable(name: "d", arg: 2, scope: !27, file: !1, line: 4, type: !16)
!30 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
!31 = distinct !DIAssignID()
!32 = !DILocation(line: 0, scope: !27, inlinedAt: !33)
!33 = distinct !DILocation(line: 13, column: 5, scope: !7)
!34 = distinct !DIAssignID()
!35 = distinct !DIAssignID()
!36 = distinct !DIAssignID()
!37 = !DILocation(line: 5, column: 19, scope: !38, inlinedAt: !33)
!38 = distinct !DILexicalBlock(scope: !27, file: !1, line: 4, column: 14)
!39 = distinct !DIAssignID()
!40 = !DILocation(line: 5, column: 12, scope: !38, inlinedAt: !33)
!41 = !DILocation(line: 5, column: 5, scope: !38, inlinedAt: !33)
!42 = !DILocation(line: 6, column: 5, scope: !38, inlinedAt: !33)
!43 = !DILocation(line: 14, column: 3, scope: !7)
!44 = !DILocation(line: 5, column: 17, scope: !38, inlinedAt: !33)
!45 = !DILocation(line: 15, column: 1, scope: !7)
!46 = distinct !DIAssignID()
!47 = !DILocation(line: 0, scope: !27)
!48 = distinct !DIAssignID()
!49 = distinct !DIAssignID()
!50 = distinct !DIAssignID()
!51 = !DILocation(line: 5, column: 19, scope: !38)
!52 = !DILocation(line: 5, column: 24, scope: !38)
!57 = !DILocation(line: 5, column: 12, scope: !38)
!58 = !DILocation(line: 5, column: 17, scope: !38)
!59 = !DILocation(line: 5, column: 5, scope: !38)
!60 = !DILocation(line: 5, column: 10, scope: !38)
!61 = !DILocation(line: 6, column: 5, scope: !38)
!62 = !DILocation(line: 6, column: 10, scope: !38)
!63 = !DILocation(line: 7, column: 3, scope: !27)
!64 = !DISubprogram(name: "esc", linkageName: "_Z3escP1v", scope: !1, file: !1, line: 10, type: !65, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
!65 = !DISubroutineType(types: !66)
!66 = !{null, !30}
!1000 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
|
