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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -hotcoldsplit -hotcoldsplit-threshold=0 < %s 2>&1 | FileCheck %s
declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture)
declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture)
declare void @cold_use(i8*) cold
declare void @use(i8*)
; In this CFG, splitting will extract the blocks extract{1,2}. I.e., it will
; extract a lifetime.start marker, but not the corresponding lifetime.end
; marker. Make sure that a lifetime.start marker is emitted before the call to
; the split function, and *only* that marker.
;
; entry
; / \
; extract1 no-extract1
; (lt.start) |
; / |
; extract2 |
; \_____ |
; \ /
; exit
; (lt.end)
;
; After splitting, we should see:
;
; entry
; / \
; codeRepl no-extract1
; (lt.start) |
; \ /
; exit
; (lt.end)
define void @only_lifetime_start_is_cold() {
; CHECK-LABEL: @only_lifetime_start_is_cold(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[LOCAL1:%.*]] = alloca i256
; CHECK-NEXT: [[LOCAL1_CAST:%.*]] = bitcast i256* [[LOCAL1]] to i8*
; CHECK-NEXT: br i1 undef, label [[CODEREPL:%.*]], label [[NO_EXTRACT1:%.*]]
; CHECK: codeRepl:
; CHECK-NEXT: [[LT_CAST:%.*]] = bitcast i256* [[LOCAL1]] to i8*
; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 -1, i8* [[LT_CAST]])
; CHECK-NEXT: [[TARGETBLOCK:%.*]] = call i1 @only_lifetime_start_is_cold.cold.1(i8* [[LOCAL1_CAST]]) #3
; CHECK-NEXT: br i1 [[TARGETBLOCK]], label [[NO_EXTRACT1]], label [[EXIT:%.*]]
; CHECK: no-extract1:
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 1, i8* [[LOCAL1_CAST]])
; CHECK-NEXT: ret void
;
entry:
%local1 = alloca i256
%local1_cast = bitcast i256* %local1 to i8*
br i1 undef, label %extract1, label %no-extract1
extract1:
; lt.start
call void @llvm.lifetime.start.p0i8(i64 1, i8* %local1_cast)
call void @cold_use(i8* %local1_cast)
br i1 undef, label %extract2, label %no-extract1
extract2:
br label %exit
no-extract1:
br label %exit
exit:
; lt.end
call void @llvm.lifetime.end.p0i8(i64 1, i8* %local1_cast)
ret void
}
; In this CFG, splitting will extract the block extract1. I.e., it will extract
; a lifetime.end marker, but not the corresponding lifetime.start marker. Do
; not emit a lifetime.end marker after the call to the split function.
;
; entry
; (lt.start)
; / \
; no-extract1 extract1
; (lt.end) (lt.end)
; \ /
; exit
;
; After splitting, we should see:
;
; entry
; (lt.start)
; / \
; no-extract1 codeRepl
; (lt.end)
; \ /
; exit
define void @only_lifetime_end_is_cold() {
; CHECK-LABEL: @only_lifetime_end_is_cold(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[LOCAL1:%.*]] = alloca i256
; CHECK-NEXT: [[LOCAL1_CAST:%.*]] = bitcast i256* [[LOCAL1]] to i8*
; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 1, i8* [[LOCAL1_CAST]])
; CHECK-NEXT: br i1 undef, label [[NO_EXTRACT1:%.*]], label [[CODEREPL:%.*]]
; CHECK: no-extract1:
; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 1, i8* [[LOCAL1_CAST]])
; CHECK-NEXT: br label [[EXIT:%.*]]
; CHECK: codeRepl:
; CHECK-NEXT: call void @only_lifetime_end_is_cold.cold.1(i8* [[LOCAL1_CAST]]) #3
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
; lt.start
%local1 = alloca i256
%local1_cast = bitcast i256* %local1 to i8*
call void @llvm.lifetime.start.p0i8(i64 1, i8* %local1_cast)
br i1 undef, label %no-extract1, label %extract1
no-extract1:
; lt.end
call void @llvm.lifetime.end.p0i8(i64 1, i8* %local1_cast)
br label %exit
extract1:
; lt.end
call void @cold_use(i8* %local1_cast)
call void @llvm.lifetime.end.p0i8(i64 1, i8* %local1_cast)
br label %exit
exit:
ret void
}
; In this CFG, splitting will extract the blocks extract{1,2,3}. Lifting the
; lifetime.end marker would be a miscompile.
define void @do_not_lift_lifetime_end() {
; CHECK-LABEL: @do_not_lift_lifetime_end(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[LOCAL1:%.*]] = alloca i256
; CHECK-NEXT: [[LOCAL1_CAST:%.*]] = bitcast i256* [[LOCAL1]] to i8*
; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 1, i8* [[LOCAL1_CAST]])
; CHECK-NEXT: br label [[HEADER:%.*]]
; CHECK: header:
; CHECK-NEXT: call void @use(i8* [[LOCAL1_CAST]])
; CHECK-NEXT: br i1 undef, label [[EXIT:%.*]], label [[CODEREPL:%.*]]
; CHECK: codeRepl:
; CHECK-NEXT: [[TARGETBLOCK:%.*]] = call i1 @do_not_lift_lifetime_end.cold.1(i8* [[LOCAL1_CAST]]) #3
; CHECK-NEXT: br i1 [[TARGETBLOCK]], label [[HEADER]], label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
; lt.start
%local1 = alloca i256
%local1_cast = bitcast i256* %local1 to i8*
call void @llvm.lifetime.start.p0i8(i64 1, i8* %local1_cast)
br label %header
header:
; If the lifetime.end marker is lifted, this use becomes dead the second time
; the header block is executed.
call void @use(i8* %local1_cast)
br i1 undef, label %exit, label %extract1
extract1:
call void @cold_use(i8* %local1_cast)
br i1 undef, label %extract2, label %extract3
extract2:
; Backedge.
br label %header
extract3:
; lt.end
call void @llvm.lifetime.end.p0i8(i64 1, i8* %local1_cast)
br label %exit
exit:
ret void
}
|
