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
137
138
139
140
141
| --- |
; RUN: llc -run-pass=machinelicm -o - %s | FileCheck %s
; Line numbers should not be retained when loop invariant instructions are hoisted.
; Doing so causes poor stepping bevavior.
;
; Created from:
; int x;
; void Process(const unsigned int *p)
; {
; while (1)
; x = *p++;
; }
;
; with clang -emit-llvm -S -O2 -g -o t.ll t.c
; llc -relocation-model=pic -stop-after=machine-combine -O2 t.ll -o t.mir
;
; We check that when the machine loop invariant pass hoists instructions
; out of a loop the debug information is not retained.
;
; CHECK-LABEL: bb.0.entry:
; CHECK: MOV64rm $rip, 1, $noreg, target-flags(x86-gotpcrel) @x, $noreg :: (load 8 from got)
; CHECK-LABEL: bb.1.while.body:
;
; ModuleID = 'tx.ll'
source_filename = "t.c"
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@x = common local_unnamed_addr global i32 0, align 4, !dbg !0
; Function Attrs: noreturn nounwind uwtable
define void @Process(i32* nocapture readonly %p) local_unnamed_addr #0 !dbg !9 {
entry:
tail call void @llvm.dbg.value(metadata i32* %p, i64 0, metadata !16, metadata !17), !dbg !18
br label %while.body, !dbg !19
while.body: ; preds = %while.body, %entry
%p.addr.0 = phi i32* [ %p, %entry ], [ %incdec.ptr, %while.body ]
tail call void @llvm.dbg.value(metadata i32* %p.addr.0, i64 0, metadata !16, metadata !17), !dbg !18
%incdec.ptr = getelementptr inbounds i32, i32* %p.addr.0, i64 1, !dbg !20
tail call void @llvm.dbg.value(metadata i32* %incdec.ptr, i64 0, metadata !16, metadata !17), !dbg !18
%0 = load i32, i32* %p.addr.0, align 4, !dbg !21, !tbaa !22
store i32 %0, i32* @x, align 4, !dbg !26, !tbaa !22
br label %while.body, !dbg !27, !llvm.loop !29
}
; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
attributes #0 = { noreturn nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind readnone }
attributes #2 = { nounwind }
!llvm.dbg.cu = !{!1}
!llvm.module.flags = !{!6, !7}
!llvm.ident = !{!8}
!0 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "x", scope: !1, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true), expr: !DIExpression())
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang version 4.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4)
!2 = !DIFile(filename: "t.c", directory: "/home/test")
!3 = !{}
!4 = !{!0}
!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!6 = !{i32 2, !"Dwarf Version", i32 4}
!7 = !{i32 2, !"Debug Info Version", i32 3}
!8 = !{!"clang version 4.0.0 "}
!9 = distinct !DISubprogram(name: "Process", scope: !2, file: !2, line: 2, type: !10, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, unit: !1, retainedNodes: !15)
!10 = !DISubroutineType(types: !11)
!11 = !{null, !12}
!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64)
!13 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !14)
!14 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
!15 = !{!16}
!16 = !DILocalVariable(name: "p", arg: 1, scope: !9, file: !2, line: 2, type: !12)
!17 = !DIExpression()
!18 = !DILocation(line: 2, column: 34, scope: !9)
!19 = !DILocation(line: 4, column: 3, scope: !9)
!20 = !DILocation(line: 5, column: 11, scope: !9)
!21 = !DILocation(line: 5, column: 9, scope: !9)
!22 = !{!23, !23, i64 0}
!23 = !{!"int", !24, i64 0}
!24 = !{!"omnipotent char", !25, i64 0}
!25 = !{!"Simple C/C++ TBAA"}
!26 = !DILocation(line: 5, column: 7, scope: !9)
!27 = !DILocation(line: 4, column: 3, scope: !28)
!28 = !DILexicalBlockFile(scope: !9, file: !2, discriminator: 1)
!29 = distinct !{!29, !19, !20}
...
---
name: Process
alignment: 16
exposesReturnsTwice: false
legalized: false
regBankSelected: false
selected: false
tracksRegLiveness: true
registers:
- { id: 0, class: gr64 }
- { id: 1, class: gr64 }
- { id: 2, class: gr64 }
- { id: 3, class: gr32 }
- { id: 4, class: gr64 }
liveins:
- { reg: '$rdi', virtual-reg: '%2' }
frameInfo:
isFrameAddressTaken: false
isReturnAddressTaken: false
hasStackMap: false
hasPatchPoint: false
stackSize: 0
offsetAdjustment: 0
maxAlignment: 0
adjustsStack: false
hasCalls: false
maxCallFrameSize: 0
hasOpaqueSPAdjustment: false
hasVAStart: false
hasMustTailInVarArgFunc: false
body: |
bb.0.entry:
successors: %bb.1.while.body(0x80000000)
liveins: $rdi
DBG_VALUE $rdi, _, !16, !17, debug-location !18
%2 = COPY $rdi
DBG_VALUE %2, _, !16, !17, debug-location !18
bb.1.while.body:
successors: %bb.1.while.body(0x80000000)
%0 = PHI %2, %bb.0.entry, %1, %bb.1.while.body
DBG_VALUE %0, _, !16, !17, debug-location !18
%1 = ADD64ri8 %0, 4, implicit-def dead $eflags, debug-location !20
DBG_VALUE %1, _, !16, !17, debug-location !18
%3 = MOV32rm %0, 1, _, 0, _, debug-location !21 :: (load 4 from %ir.p.addr.0, !tbaa !22)
%4 = MOV64rm $rip, 1, _, target-flags(x86-gotpcrel) @x, _, debug-location !26 :: (load 8 from got)
MOV32mr killed %4, 1, _, 0, _, killed %3, debug-location !26 :: (store 4 into @x, !tbaa !22)
JMP_1 %bb.1.while.body, debug-location !27
...
|