1; RUN: opt -instcombine -S %s | FileCheck %s
2
3;; Ensure that debug uses of a select are replaced when the select is replaced
4;; with one of its operands in InstCombine's replacedSelectWithOperand.
5
6;; Based on IR generated from this source, compiled with -O2 -g:
7;;
8;; extern void* glob;
9;; struct Thing {
10;;   void *ptr;
11;;   void *get() {return ptr;}
12;; };
13;; Thing *two(void *in) {
14;;   if ((long)in & 1)
15;;     return nullptr;
16;;   return static_cast<Thing *>(in);
17;; }
18;; void one() {
19;;   if (Thing *a = two(glob))
20;;     // Without the fix we lose 'this' (a) in the inlined call below.
21;;     glob = a->get();
22;; }
23
24;; Look at the instruction:
25;;     %retval.0.i = select i1 %tobool.not.i, %struct.Thing* %2, %struct.Thing* null
26;; Note that %2 is a bitcast of %0.
27;; InstCombine replaces the use of %retval.0.i in if.then with %0 because
28;; if.then is only branched to when retval.0.is not null. Ensure that debug use
29;; of %retval.0.i is also replaced with %0.
30
31; CHECK: if.then:
32; CHECK-NEXT: call void @llvm.dbg.value(metadata i8* %0, metadata ![[THIS:[0-9]+]], metadata !DIExpression())
33; CHECK: ![[THIS]] = !DILocalVariable(name: "this",
34
35target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
36target triple = "x86_64-unknown-linux-gnu"
37
38%struct.Thing = type { i8* }
39
40@glob = external dso_local local_unnamed_addr global i8*, align 8
41
42define dso_local void @_Z3onev() local_unnamed_addr !dbg !29 {
43entry:
44  %0 = load i8*, i8** @glob, align 8, !dbg !35
45  call void @llvm.dbg.value(metadata i8* %0, metadata !22, metadata !DIExpression()), !dbg !40
46  %1 = ptrtoint i8* %0 to i64, !dbg !42
47  %and.i = and i64 %1, 1, !dbg !43
48  %tobool.not.i = icmp eq i64 %and.i, 0, !dbg !42
49  %2 = bitcast i8* %0 to %struct.Thing*, !dbg !44
50  %retval.0.i = select i1 %tobool.not.i, %struct.Thing* %2, %struct.Thing* null, !dbg !44
51  call void @llvm.dbg.value(metadata %struct.Thing* %retval.0.i, metadata !33, metadata !DIExpression()), !dbg !45
52  %tobool.not = icmp eq %struct.Thing* %retval.0.i, null, !dbg !46
53  br i1 %tobool.not, label %if.end, label %if.then, !dbg !47
54
55if.then:                                          ; preds = %entry
56  call void @llvm.dbg.value(metadata %struct.Thing* %retval.0.i, metadata !48, metadata !DIExpression()), !dbg !51
57  %ptr.i = getelementptr inbounds %struct.Thing, %struct.Thing* %retval.0.i, i64 0, i32 0, !dbg !53
58  %3 = load i8*, i8** %ptr.i, align 8, !dbg !53
59  store i8* %3, i8** @glob, align 8, !dbg !56
60  br label %if.end, !dbg !57
61
62if.end:                                           ; preds = %if.then, %entry
63  ret void, !dbg !58
64}
65
66declare void @llvm.dbg.value(metadata, metadata, metadata)
67
68!llvm.dbg.cu = !{!0}
69!llvm.module.flags = !{!14, !15, !16}
70!llvm.ident = !{!17}
71
72!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 13.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, splitDebugInlining: false, nameTableKind: None)
73!1 = !DIFile(filename: "test.cpp", directory: "/")
74!2 = !{}
75!3 = !{!4, !5}
76!4 = !DIBasicType(name: "long int", size: 64, encoding: DW_ATE_signed)
77!5 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !6, size: 64)
78!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Thing", file: !1, line: 2, size: 64, flags: DIFlagTypePassByValue, elements: !7, identifier: "_ZTS5Thing")
79!7 = !{!8, !10}
80!8 = !DIDerivedType(tag: DW_TAG_member, name: "ptr", scope: !6, file: !1, line: 3, baseType: !9, size: 64)
81!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
82!10 = !DISubprogram(name: "get", linkageName: "_ZN5Thing3getEv", scope: !6, file: !1, line: 4, type: !11, scopeLine: 4, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
83!11 = !DISubroutineType(types: !12)
84!12 = !{!9, !13}
85!13 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !6, size: 64, flags: DIFlagArtificial | DIFlagObjectPointer)
86!14 = !{i32 7, !"Dwarf Version", i32 4}
87!15 = !{i32 2, !"Debug Info Version", i32 3}
88!16 = !{i32 1, !"wchar_size", i32 4}
89!17 = !{!"clang version 13.0.0"}
90!18 = distinct !DISubprogram(name: "two", linkageName: "_Z3twoPv", scope: !1, file: !1, line: 6, type: !19, scopeLine: 6, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !21)
91!19 = !DISubroutineType(types: !20)
92!20 = !{!5, !9}
93!21 = !{!22}
94!22 = !DILocalVariable(name: "in", arg: 1, scope: !18, file: !1, line: 6, type: !9)
95!23 = !DILocation(line: 0, scope: !18)
96!24 = !DILocation(line: 7, column: 7, scope: !25)
97!25 = distinct !DILexicalBlock(scope: !18, file: !1, line: 7, column: 7)
98!26 = !DILocation(line: 7, column: 16, scope: !25)
99!27 = !DILocation(line: 7, column: 7, scope: !18)
100!28 = !DILocation(line: 10, column: 1, scope: !18)
101!29 = distinct !DISubprogram(name: "one", linkageName: "_Z3onev", scope: !1, file: !1, line: 11, type: !30, scopeLine: 11, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !32)
102!30 = !DISubroutineType(types: !31)
103!31 = !{null}
104!32 = !{!33}
105!33 = !DILocalVariable(name: "a", scope: !34, file: !1, line: 12, type: !5)
106!34 = distinct !DILexicalBlock(scope: !29, file: !1, line: 12, column: 14)
107!35 = !DILocation(line: 12, column: 22, scope: !34)
108!40 = !DILocation(line: 0, scope: !18, inlinedAt: !41)
109!41 = distinct !DILocation(line: 12, column: 18, scope: !34)
110!42 = !DILocation(line: 7, column: 7, scope: !25, inlinedAt: !41)
111!43 = !DILocation(line: 7, column: 16, scope: !25, inlinedAt: !41)
112!44 = !DILocation(line: 7, column: 7, scope: !18, inlinedAt: !41)
113!45 = !DILocation(line: 0, scope: !34)
114!46 = !DILocation(line: 12, column: 14, scope: !34)
115!47 = !DILocation(line: 12, column: 14, scope: !29)
116!48 = !DILocalVariable(name: "this", arg: 1, scope: !49, type: !5, flags: DIFlagArtificial | DIFlagObjectPointer)
117!49 = distinct !DISubprogram(name: "get", linkageName: "_ZN5Thing3getEv", scope: !6, file: !1, line: 4, type: !11, scopeLine: 4, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, declaration: !10, retainedNodes: !50)
118!50 = !{!48}
119!51 = !DILocation(line: 0, scope: !49, inlinedAt: !52)
120!52 = distinct !DILocation(line: 14, column: 15, scope: !34)
121!53 = !DILocation(line: 4, column: 23, scope: !49, inlinedAt: !52)
122!56 = !DILocation(line: 14, column: 10, scope: !34)
123!57 = !DILocation(line: 14, column: 5, scope: !34)
124!58 = !DILocation(line: 15, column: 1, scope: !29)
125!59 = !DILocation(line: 0, scope: !49)
126!60 = !DILocation(line: 4, column: 23, scope: !49)
127!61 = !DILocation(line: 4, column: 16, scope: !49)
128