1; REQUIRES: object-emission
2
3; RUN: llc -mtriple=x86_64-apple-macosx10.10.0 -o %t %s
4
5; Testcase generated from:
6; #include <stdint.h>
7; int foo(int a) {
8;     int b = (int16_t)a + 8;
9;     int c = (int16_t)b + 8;
10;     int d = (int16_t)c + 8;
11;     int e = (int16_t)d + 8;
12;     int f = (int16_t)e + 8;
13;     return f;
14; }
15; by emitting the IR and then manually applying mem2reg to it.
16
17; This testcase would trigger the assert commited along with it if the
18; fix of r221709 isn't applied. There is no other check except the successful
19; run of llc.
20; What happened before r221709, is that SDDbgInfo (the data structure helping
21; SelectionDAG to keep track of dbg.values) kept a map keyed by SDNode pointers.
22; This map was never purged when the SDNodes were deallocated and thus if a new
23; SDNode was allocated in the same memory, it would have an entry in the SDDbgInfo
24; map upon creation (Reallocation in the same memory can happen easily as
25; SelectionDAG uses a Recycling allocator). This behavior could turn into a
26; pathological memory consumption explosion if the DAG combiner hit the 'right'
27; allocation patterns as could be seen in PR20893.
28; By nature, this test could bitrot quite easily. If it doesn't trigger an assert
29; when run with r221709 reverted, then it really doesn't test anything anymore.
30
31; Function Attrs: nounwind ssp uwtable
32define i32 @foo(i32 %a) #0 {
33entry:
34  call void @llvm.dbg.value(metadata i32 %a, i64 0, metadata !16, metadata !17), !dbg !18
35  %conv = trunc i32 %a to i16, !dbg !19
36  %conv1 = sext i16 %conv to i32, !dbg !19
37  %add = add nsw i32 %conv1, 8, !dbg !19
38  call void @llvm.dbg.value(metadata i32 %add, i64 0, metadata !20, metadata !17), !dbg !21
39  %conv2 = trunc i32 %add to i16, !dbg !22
40  %conv3 = sext i16 %conv2 to i32, !dbg !22
41  %add4 = add nsw i32 %conv3, 8, !dbg !22
42  call void @llvm.dbg.value(metadata i32 %add4, i64 0, metadata !23, metadata !17), !dbg !24
43  %conv5 = trunc i32 %add4 to i16, !dbg !25
44  %conv6 = sext i16 %conv5 to i32, !dbg !25
45  %add7 = add nsw i32 %conv6, 8, !dbg !25
46  call void @llvm.dbg.value(metadata i32 %add7, i64 0, metadata !26, metadata !17), !dbg !27
47  %conv8 = trunc i32 %add7 to i16, !dbg !28
48  %conv9 = sext i16 %conv8 to i32, !dbg !28
49  %add10 = add nsw i32 %conv9, 8, !dbg !28
50  call void @llvm.dbg.value(metadata i32 %add10, i64 0, metadata !29, metadata !17), !dbg !30
51  %conv11 = trunc i32 %add10 to i16, !dbg !31
52  %conv12 = sext i16 %conv11 to i32, !dbg !31
53  %add13 = add nsw i32 %conv12, 8, !dbg !31
54  call void @llvm.dbg.value(metadata i32 %add13, i64 0, metadata !32, metadata !17), !dbg !33
55  ret i32 %add13, !dbg !34
56}
57
58; Function Attrs: nounwind readnone
59declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
60
61; Function Attrs: nounwind readnone
62declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
63
64attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
65attributes #1 = { nounwind readnone }
66
67!llvm.dbg.cu = !{!0}
68!llvm.module.flags = !{!13, !14}
69!llvm.ident = !{!15}
70
71!0 = !{!"0x11\0012\00clang version 3.6.0 \000\00\000\00\001", !1, !2, !3, !7, !2, !2} ; [ DW_TAG_compile_unit ] [/tmp/ghost-sdnode-dbgvalues.c] [DW_LANG_C99]
72!1 = !{!"ghost-sdnode-dbgvalues.c", !"/tmp"}
73!2 = !{}
74!3 = !{!4}
75!4 = !{!"0x16\00int16_t\0030\000\000\000\000", !5, null, !6} ; [ DW_TAG_typedef ] [int16_t] [line 30, size 0, align 0, offset 0] [from short]
76!5 = !{!"/usr/include/sys/_types/_int16_t.h", !"/tmp"}
77!6 = !{!"0x24\00short\000\0016\0016\000\000\005", null, null} ; [ DW_TAG_base_type ] [short] [line 0, size 16, align 16, offset 0, enc DW_ATE_signed]
78!7 = !{!8}
79!8 = !{!"0x2e\00foo\00foo\00\003\000\001\000\000\00256\000\003", !1, !9, !10, null, i32 (i32)* @foo, null, null, !2} ; [ DW_TAG_subprogram ] [line 3] [def] [foo]
80!9 = !{!"0x29", !1}    ; [ DW_TAG_file_type ] [/tmp/ghost-sdnode-dbgvalues.c]
81!10 = !{!"0x15\00\000\000\000\000\000\000", null, null, null, !11, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
82!11 = !{!12, !12}
83!12 = !{!"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
84!13 = !{i32 2, !"Dwarf Version", i32 2}
85!14 = !{i32 2, !"Debug Info Version", i32 2}
86!15 = !{!"clang version 3.6.0 "}
87!16 = !{!"0x101\00a\0016777219\000", !8, !9, !12} ; [ DW_TAG_arg_variable ] [a] [line 3]
88!17 = !{!"0x102"}               ; [ DW_TAG_expression ]
89!18 = !MDLocation(line: 3, column: 13, scope: !8)
90!19 = !MDLocation(line: 4, column: 5, scope: !8)
91!20 = !{!"0x100\00b\004\000", !8, !9, !12} ; [ DW_TAG_auto_variable ] [b] [line 4]
92!21 = !MDLocation(line: 4, column: 9, scope: !8)
93!22 = !MDLocation(line: 5, column: 5, scope: !8)
94!23 = !{!"0x100\00c\005\000", !8, !9, !12} ; [ DW_TAG_auto_variable ] [c] [line 5]
95!24 = !MDLocation(line: 5, column: 9, scope: !8)
96!25 = !MDLocation(line: 6, column: 5, scope: !8)
97!26 = !{!"0x100\00d\006\000", !8, !9, !12} ; [ DW_TAG_auto_variable ] [d] [line 6]
98!27 = !MDLocation(line: 6, column: 9, scope: !8)
99!28 = !MDLocation(line: 7, column: 5, scope: !8)
100!29 = !{!"0x100\00e\007\000", !8, !9, !12} ; [ DW_TAG_auto_variable ] [e] [line 7]
101!30 = !MDLocation(line: 7, column: 9, scope: !8)
102!31 = !MDLocation(line: 8, column: 5, scope: !8)
103!32 = !{!"0x100\00f\008\000", !8, !9, !12} ; [ DW_TAG_auto_variable ] [f] [line 8]
104!33 = !MDLocation(line: 8, column: 9, scope: !8)
105!34 = !MDLocation(line: 9, column: 5, scope: !8)
106