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1; RUN: llc < %s | FileCheck %s
2
3; Reduced manually from C source:
4; unsigned __attribute__((noinline, optnone)) useslot(unsigned v) { return v; }
5; void __attribute__((noinline)) f(unsigned cell_offset, unsigned *page_start_) {
6;   unsigned cell = page_start_[0];
7;   while (cell) {
8;     unsigned bit_offset = cell_offset ? __builtin_ctz(cell) : 32;
9;     unsigned bit_mask = 1U << bit_offset;
10;     unsigned slot = (cell_offset + bit_offset) << /*log2(sizeof(void*))*/ 3;
11;     cell ^= bit_mask + page_start_[slot];
12;   }
13; }
14; int main() {
15;   static unsigned pages[32] = {1, 2, 3, 4, 5, 6, 7};
16;   f(3, &pages[0]);
17; }
18
19; We had a bug where the DBG_VALUE instruction for bit_offset would be emitted
20; at the end of the basic block, long after its actual program point. What's
21; interesting in this example is that the !range metadata produces an AssertSext
22; DAG node that gets replaced during ISel. This leads to an unordered SDDbgValue
23; vector, which has to be sorted by IR order before it is processed in parallel
24; with the Orders insertion point vector.
25
26; CHECK-LABEL: f: # @f
27; CHECK: .LBB0_2:                                # %while.body
28; CHECK:         movl    $32, %ecx
29; CHECK:         testl   {{.*}}
30; CHECK:         jne     .LBB0_4
31; CHECK: # %bb.3:                                 # %if.then
32; CHECK:         callq   if_then
33; CHECK:         movl    %eax, %ecx
34; CHECK: .LBB0_4:                                # %if.end
35;        Check that this DEBUG_VALUE comes before the left shift.
36; CHECK:         #DEBUG_VALUE: bit_offset <- $ecx
37; CHECK:         .cv_loc 0 1 8 28                # t.c:8:28
38; CHECK:         movl    $1, %[[reg:[^ ]*]]
39; CHECK:         shll    %cl, %[[reg]]
40
41; ModuleID = 't.c'
42source_filename = "t.c"
43target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
44target triple = "x86_64-pc-windows-msvc19.0.24215"
45
46; Function Attrs: nounwind readnone speculatable
47declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
48
49declare i32 @if_then()
50
51; Function Attrs: noinline nounwind readonly uwtable
52define void @f(i32 %cell_offset, i32* nocapture %page_start_) local_unnamed_addr #0 !dbg !31 {
53entry:
54  %0 = load i32, i32* %page_start_, align 4, !dbg !45
55  %tobool14 = icmp eq i32 %0, 0, !dbg !47
56  br i1 %tobool14, label %while.end, label %while.body, !dbg !47
57
58while.body:                                       ; preds = %while.body.lr.ph, %while.body
59  %cell.015 = phi i32 [ %0, %entry ], [ %xor, %if.end ]
60  %tobool1 = icmp eq i32 %cell_offset, 0
61  br i1 %tobool1, label %if.then, label %if.end
62
63if.then:
64  %1 = call i32 @if_then(), !dbg !48, !range !49
65  br label %if.end
66
67if.end:
68  %cond = phi i32 [ %1, %if.then ], [ 32, %while.body ]
69  tail call void @llvm.dbg.value(metadata i32 %cond, metadata !39, metadata !DIExpression()), !dbg !51
70  %shl = shl i32 1, %cond, !dbg !52
71  %add = add i32 %cond, %cell_offset, !dbg !54
72  %shl2 = shl i32 %add, 3, !dbg !55
73  %idxprom = zext i32 %shl2 to i64, !dbg !57
74  %arrayidx3 = getelementptr inbounds i32, i32* %page_start_, i64 %idxprom, !dbg !57
75  %2 = load i32, i32* %arrayidx3, align 4, !dbg !57
76  %add4 = add i32 %2, %shl, !dbg !58
77  %xor = xor i32 %add4, %cell.015, !dbg !59
78  tail call void @llvm.dbg.value(metadata i32 %xor, metadata !38, metadata !DIExpression()), !dbg !46
79  %tobool = icmp eq i32 %xor, 0, !dbg !47
80  br i1 %tobool, label %while.end, label %while.body, !dbg !47, !llvm.loop !60
81
82while.end:                                        ; preds = %while.body, %entry
83  ret void, !dbg !62
84}
85
86; Function Attrs: nounwind readnone speculatable
87declare i32 @llvm.cttz.i32(i32, i1) #1
88
89; Function Attrs: nounwind readnone speculatable
90declare void @llvm.dbg.value(metadata, metadata, metadata) #1
91
92attributes #0 = { noinline nounwind readonly uwtable }
93attributes #1 = { nounwind readnone speculatable }
94
95!llvm.dbg.cu = !{!0}
96!llvm.module.flags = !{!14, !15, !16, !17}
97!llvm.ident = !{!18}
98
99!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3)
100!1 = !DIFile(filename: "t.c", directory: "C:\5Csrc\5Cllvm-project\5Cbuild", checksumkind: CSK_MD5, checksum: "f80d0003faf76554dfdec6c95da285cc")
101!2 = !{}
102!3 = !{!4}
103!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
104!5 = distinct !DIGlobalVariable(name: "pages", scope: !6, file: !1, line: 18, type: !10, isLocal: true, isDefinition: true)
105!6 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 17, type: !7, isLocal: false, isDefinition: true, scopeLine: 17, isOptimized: true, unit: !0, retainedNodes: !2)
106!7 = !DISubroutineType(types: !8)
107!8 = !{!9}
108!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
109!10 = !DICompositeType(tag: DW_TAG_array_type, baseType: !11, size: 1024, elements: !12)
110!11 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
111!12 = !{!13}
112!13 = !DISubrange(count: 32)
113!14 = !{i32 2, !"CodeView", i32 1}
114!15 = !{i32 2, !"Debug Info Version", i32 3}
115!16 = !{i32 1, !"wchar_size", i32 2}
116!17 = !{i32 7, !"PIC Level", i32 2}
117!18 = !{!"clang version 6.0.0 "}
118!31 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 4, type: !32, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !35)
119!32 = !DISubroutineType(types: !33)
120!33 = !{null, !11, !34}
121!34 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64)
122!35 = !{!36, !37, !38, !39, !41, !42}
123!36 = !DILocalVariable(name: "page_start_", arg: 2, scope: !31, file: !1, line: 4, type: !34)
124!37 = !DILocalVariable(name: "cell_offset", arg: 1, scope: !31, file: !1, line: 4, type: !11)
125!38 = !DILocalVariable(name: "cell", scope: !31, file: !1, line: 5, type: !11)
126!39 = !DILocalVariable(name: "bit_offset", scope: !40, file: !1, line: 7, type: !11)
127!40 = distinct !DILexicalBlock(scope: !31, file: !1, line: 6, column: 16)
128!41 = !DILocalVariable(name: "bit_mask", scope: !40, file: !1, line: 8, type: !11)
129!42 = !DILocalVariable(name: "slot", scope: !40, file: !1, line: 9, type: !11)
130!43 = !DILocation(line: 4, column: 66, scope: !31)
131!44 = !DILocation(line: 4, column: 43, scope: !31)
132!45 = !DILocation(line: 5, column: 19, scope: !31)
133!46 = !DILocation(line: 5, column: 12, scope: !31)
134!47 = !DILocation(line: 6, column: 3, scope: !31)
135!48 = !DILocation(line: 7, column: 41, scope: !40)
136!49 = !{i32 0, i32 33}
137!50 = !DILocation(line: 7, column: 27, scope: !40)
138!51 = !DILocation(line: 7, column: 14, scope: !40)
139!52 = !DILocation(line: 8, column: 28, scope: !40)
140!53 = !DILocation(line: 8, column: 14, scope: !40)
141!54 = !DILocation(line: 9, column: 34, scope: !40)
142!55 = !DILocation(line: 9, column: 48, scope: !40)
143!56 = !DILocation(line: 9, column: 14, scope: !40)
144!57 = !DILocation(line: 13, column: 24, scope: !40)
145!58 = !DILocation(line: 13, column: 22, scope: !40)
146!59 = !DILocation(line: 13, column: 10, scope: !40)
147!60 = distinct !{!60, !47, !61}
148!61 = !DILocation(line: 14, column: 3, scope: !31)
149!62 = !DILocation(line: 15, column: 1, scope: !31)
150