xref: /llvm-project/llvm/test/Transforms/InstCombine/debuginfo-dce.ll (revision 094572701dce4aaf36f4521d6cf750420d39f206) 
1; RUN: opt -passes=instcombine %s -S -o - | FileCheck %s
2; RUN: opt -passes=instcombine %s -S -o - --try-experimental-debuginfo-iterators | FileCheck %s
3; Verify that the eliminated instructions (bitcast, gep, load) are salvaged into
4; a DIExpression.
5;
6; Originally created from the following C source and then heavily isolated/reduced.
7;
8; struct entry {
9;   struct entry *next;
10; };
11; void scan(struct entry *queue, struct entry *end)
12; {
13;   struct entry *entry;
14;   for (entry = (struct entry *)((char *)(queue->next) - 8);
15;        &entry->next == end;
16;        entry = (struct entry *)((char *)(entry->next) - 8)) {
17;   }
18; }
19
20; ModuleID = '<stdin>'
21source_filename = "test.c"
22target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
23target triple = "x86_64-apple-macosx10.12.0"
24
25%struct.entry = type { ptr }
26
27; This salvage can't currently occur safely (PR40628), however if/when that's
28; ever fixed, then this is definitely a piece of test coverage that should
29; be maintained.
30define void @salvage_load(ptr %queue) local_unnamed_addr #0 !dbg !14 {
31entry:
32  %im_not_dead = alloca ptr
33  %0 = load ptr, ptr %queue, align 8, !dbg !19
34  %1 = load ptr, ptr %queue, align 8, !dbg !19
35  call void @llvm.dbg.value(metadata ptr %1, metadata !18, metadata !20), !dbg !19
36; CHECK: define void @salvage_load
37; CHECK-NEXT: entry:
38; CHECK-NEXT: #dbg_value(ptr poison
39  store ptr %1, ptr %im_not_dead, align 8
40  ret void, !dbg !21
41}
42
43define void @salvage_bitcast(ptr %queue) local_unnamed_addr #0 !dbg !22 {
44entry:
45  %im_not_dead = alloca ptr
46  call void @llvm.dbg.value(metadata ptr %queue, metadata !24, metadata !20), !dbg !23
47; CHECK: define void @salvage_bitcast
48; CHECK-NEXT: entry:
49; CHECK-NEXT: #dbg_value(ptr %queue,
50; CHECK-SAME:                           !DIExpression(DW_OP_plus_uconst, 0),
51  store ptr %queue, ptr %im_not_dead, align 8
52  ret void, !dbg !23
53}
54
55define void @salvage_gep0(ptr %queue, ptr %end) local_unnamed_addr #0 !dbg !25 {
56entry:
57  %im_not_dead = alloca ptr
58  %0 = getelementptr inbounds %struct.entry, ptr %queue, i32 -1, i32 0, !dbg !26
59  %1 = getelementptr inbounds %struct.entry, ptr %queue, i32 -1, i32 0, !dbg !26
60  call void @llvm.dbg.value(metadata ptr %1, metadata !27, metadata !20), !dbg !26
61; CHECK: define void @salvage_gep0
62; CHECK-NEXT: entry:
63; CHECK-NEXT: #dbg_value(ptr %queue,
64; CHECK-SAME:                           !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_stack_value),
65  store ptr %1, ptr %im_not_dead, align 8
66  ret void, !dbg !26
67}
68
69define void @salvage_gep1(ptr %queue, ptr %end) local_unnamed_addr #0 !dbg !28 {
70entry:
71  %im_not_dead = alloca ptr
72  %0 = getelementptr inbounds %struct.entry, ptr %queue, i32 -1, i32 0, !dbg !29
73  %1 = getelementptr inbounds %struct.entry, ptr %queue, i32 -1, i32 0, !dbg !29
74  call void @llvm.dbg.value(metadata ptr %1, metadata !30, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32)), !dbg !29
75; CHECK: define void @salvage_gep1
76; CHECK-NEXT: entry:
77; CHECK-NEXT: #dbg_value(ptr %queue,
78; CHECK-SAME:     !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 32),
79  store ptr %1, ptr %im_not_dead, align 8
80  ret void, !dbg !29
81}
82
83define void @salvage_gep2(ptr %queue, ptr %end) local_unnamed_addr #0 !dbg !31 {
84entry:
85  %im_not_dead = alloca ptr
86  %0 = getelementptr inbounds %struct.entry, ptr %queue, i32 -1, i32 0, !dbg !32
87  %1 = getelementptr inbounds %struct.entry, ptr %queue, i32 -1, i32 0, !dbg !32
88  call void @llvm.dbg.value(metadata ptr %1, metadata !33, metadata !DIExpression(DW_OP_stack_value)), !dbg !32
89; CHECK: define void @salvage_gep2
90; CHECK-NEXT: entry:
91; CHECK-NEXT: #dbg_value(ptr %queue,
92; CHECK-SAME:     !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_stack_value),
93  store ptr %1, ptr %im_not_dead, align 8
94  ret void, !dbg !32
95}
96
97; Function Attrs: nounwind readnone
98declare void @llvm.dbg.value(metadata, metadata, metadata) #1
99
100attributes #0 = { nounwind ssp uwtable }
101attributes #1 = { nounwind readnone }
102
103!llvm.dbg.cu = !{!0}
104!llvm.module.flags = !{!10, !11, !12}
105!llvm.ident = !{!13}
106
107!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 5.0.0 (trunk 297628) (llvm/trunk 297643)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3)
108!1 = !DIFile(filename: "test.c", directory: "/")
109!2 = !{}
110!3 = !{!4, !8}
111!4 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !5, size: 64)
112!5 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "entry", file: !1, line: 1, size: 64, elements: !6)
113!6 = !{!7}
114!7 = !DIDerivedType(tag: DW_TAG_member, name: "next", scope: !5, file: !1, line: 2, baseType: !4, size: 64)
115!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64)
116!9 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
117!10 = !{i32 2, !"Dwarf Version", i32 4}
118!11 = !{i32 2, !"Debug Info Version", i32 3}
119!12 = !{i32 1, !"PIC Level", i32 2}
120!13 = !{!"clang version 5.0.0 (trunk 297628) (llvm/trunk 297643)"}
121!14 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !15, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !17)
122!15 = !DISubroutineType(types: !16)
123!16 = !{null, !4, !4}
124!17 = !{!18}
125!18 = !DILocalVariable(name: "entry", scope: !14, file: !1, line: 6, type: !4)
126!19 = !DILocation(line: 6, column: 17, scope: !14)
127!20 = !DIExpression(DW_OP_plus_uconst, 0)
128!21 = !DILocation(line: 11, column: 1, scope: !14)
129!22 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !15, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !17)
130!23 = !DILocation(line: 6, column: 17, scope: !22)
131!24 = !DILocalVariable(name: "entry", scope: !22, file: !1, line: 6, type: !4)
132!25 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !15, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !17)
133!26 = !DILocation(line: 6, column: 17, scope: !25)
134!27 = !DILocalVariable(name: "entry", scope: !25, file: !1, line: 6, type: !4)
135!28 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !15, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !17)
136!29 = !DILocation(line: 6, column: 17, scope: !28)
137!30 = !DILocalVariable(name: "entry", scope: !28, file: !1, line: 6, type: !4)
138!31 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !15, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !17)
139!32 = !DILocation(line: 6, column: 17, scope: !31)
140!33 = !DILocalVariable(name: "entry", scope: !31, file: !1, line: 6, type: !4)
141