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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
|
; RUN: opt -simplifycfg -S -o - < %s | FileCheck %s
declare void @helper(i32)
define void @test1(i1 %a, i1 %b) {
; CHECK-LABEL: @test1(
entry:
br i1 %a, label %Y, label %X, !prof !0
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !0
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y, !prof !1
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test2(i1 %a, i1 %b) {
; CHECK-LABEL: @test2(
entry:
br i1 %a, label %X, label %Y, !prof !1
; CHECK: br i1 %or.cond, label %Z, label %Y, !prof !1
; CHECK-NOT: !prof
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y, !prof !2
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test3(i1 %a, i1 %b) {
; CHECK-LABEL: @test3(
; CHECK-NOT: !prof
entry:
br i1 %a, label %X, label %Y, !prof !1
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test4(i1 %a, i1 %b) {
; CHECK-LABEL: @test4(
; CHECK-NOT: !prof
entry:
br i1 %a, label %X, label %Y
X:
%c = or i1 %b, false
br i1 %c, label %Z, label %Y, !prof !1
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
;; test5 - The case where it jumps to the default target will be removed.
define void @test5(i32 %M, i32 %N) nounwind uwtable {
entry:
switch i32 %N, label %sw2 [
i32 1, label %sw2
i32 2, label %sw.bb
i32 3, label %sw.bb1
], !prof !3
; CHECK: test5
; CHECK: switch i32 %N, label %sw2 [
; CHECK: i32 3, label %sw.bb1
; CHECK: i32 2, label %sw.bb
; CHECK: ], !prof !2
sw.bb:
call void @helper(i32 0)
br label %sw.epilog
sw.bb1:
call void @helper(i32 1)
br label %sw.epilog
sw2:
call void @helper(i32 2)
br label %sw.epilog
sw.epilog:
ret void
}
;; test6 - Some cases of the second switch are pruned during optimization.
;; Then the second switch will be converted to a branch, finally, the first
;; switch and the branch will be merged into a single switch.
define void @test6(i32 %M, i32 %N) nounwind uwtable {
entry:
switch i32 %N, label %sw2 [
i32 1, label %sw2
i32 2, label %sw.bb
i32 3, label %sw.bb1
], !prof !4
; CHECK: test6
; CHECK: switch i32 %N, label %sw.epilog
; CHECK: i32 3, label %sw.bb1
; CHECK: i32 2, label %sw.bb
; CHECK: i32 4, label %sw.bb5
; CHECK: ], !prof !3
sw.bb:
call void @helper(i32 0)
br label %sw.epilog
sw.bb1:
call void @helper(i32 1)
br label %sw.epilog
sw2:
;; Here "case 2" is invalidated since the default case of the first switch
;; does not include "case 2".
switch i32 %N, label %sw.epilog [
i32 2, label %sw.bb4
i32 4, label %sw.bb5
], !prof !5
sw.bb4:
call void @helper(i32 2)
br label %sw.epilog
sw.bb5:
call void @helper(i32 3)
br label %sw.epilog
sw.epilog:
ret void
}
;; This test is based on test1 but swapped the targets of the second branch.
define void @test1_swap(i1 %a, i1 %b) {
; CHECK-LABEL: @test1_swap(
entry:
br i1 %a, label %Y, label %X, !prof !0
; CHECK: br i1 %or.cond, label %Y, label %Z, !prof !4
X:
%c = or i1 %b, false
br i1 %c, label %Y, label %Z, !prof !1
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
define void @test7(i1 %a, i1 %b) {
; CHECK-LABEL: @test7(
entry:
%c = or i1 %b, false
br i1 %a, label %Y, label %X, !prof !0
; CHECK: br i1 %brmerge, label %Y, label %Z, !prof !5
X:
br i1 %c, label %Y, label %Z, !prof !6
Y:
call void @helper(i32 0)
ret void
Z:
call void @helper(i32 1)
ret void
}
; Test basic folding to a conditional branch.
define void @test8(i64 %x, i64 %y) nounwind {
; CHECK-LABEL: @test8(
entry:
%lt = icmp slt i64 %x, %y
; CHECK: br i1 %lt, label %a, label %b, !prof !6
%qux = select i1 %lt, i32 0, i32 2
switch i32 %qux, label %bees [
i32 0, label %a
i32 1, label %b
i32 2, label %b
], !prof !7
a:
call void @helper(i32 0) nounwind
ret void
b:
call void @helper(i32 1) nounwind
ret void
bees:
call void @helper(i32 2) nounwind
ret void
}
; Test edge splitting when the default target has icmp and unconditinal
; branch
define i1 @test9(i32 %x, i32 %y) nounwind {
; CHECK-LABEL: @test9(
entry:
switch i32 %x, label %bees [
i32 0, label %a
i32 1, label %end
i32 2, label %end
], !prof !7
; CHECK: switch i32 %x, label %bees [
; CHECK: i32 0, label %a
; CHECK: i32 1, label %end
; CHECK: i32 2, label %end
; CHECK: i32 92, label %end
; CHECK: ], !prof !7
a:
call void @helper(i32 0) nounwind
%reta = icmp slt i32 %x, %y
ret i1 %reta
bees:
%tmp = icmp eq i32 %x, 92
br label %end
end:
; CHECK: end:
; CHECK: %ret = phi i1 [ true, %entry ], [ false, %bees ], [ true, %entry ], [ true, %entry ]
%ret = phi i1 [ true, %entry ], [%tmp, %bees], [true, %entry]
call void @helper(i32 2) nounwind
ret i1 %ret
}
define void @test10(i32 %x) nounwind readnone ssp noredzone {
entry:
switch i32 %x, label %lor.rhs [
i32 2, label %lor.end
i32 1, label %lor.end
i32 3, label %lor.end
], !prof !7
lor.rhs:
call void @helper(i32 1) nounwind
ret void
lor.end:
call void @helper(i32 0) nounwind
ret void
; CHECK: test10
; CHECK: %x.off = add i32 %x, -1
; CHECK: %switch = icmp ult i32 %x.off, 3
; CHECK: br i1 %switch, label %lor.end, label %lor.rhs, !prof !8
}
; Remove dead cases from the switch.
define void @test11(i32 %x) nounwind {
%i = shl i32 %x, 1
switch i32 %i, label %a [
i32 21, label %b
i32 24, label %c
], !prof !8
; CHECK: %cond = icmp eq i32 %i, 24
; CHECK: br i1 %cond, label %c, label %a, !prof !9
a:
call void @helper(i32 0) nounwind
ret void
b:
call void @helper(i32 1) nounwind
ret void
c:
call void @helper(i32 2) nounwind
ret void
}
!0 = metadata !{metadata !"branch_weights", i32 3, i32 5}
!1 = metadata !{metadata !"branch_weights", i32 1, i32 1}
!2 = metadata !{metadata !"branch_weights", i32 1, i32 2}
!3 = metadata !{metadata !"branch_weights", i32 4, i32 3, i32 2, i32 1}
!4 = metadata !{metadata !"branch_weights", i32 4, i32 3, i32 2, i32 1}
!5 = metadata !{metadata !"branch_weights", i32 7, i32 6, i32 5}
!6 = metadata !{metadata !"branch_weights", i32 1, i32 3}
!7 = metadata !{metadata !"branch_weights", i32 33, i32 9, i32 8, i32 7}
!8 = metadata !{metadata !"branch_weights", i32 33, i32 9, i32 8}
; CHECK: !0 = metadata !{metadata !"branch_weights", i32 5, i32 11}
; CHECK: !1 = metadata !{metadata !"branch_weights", i32 1, i32 5}
; CHECK: !2 = metadata !{metadata !"branch_weights", i32 7, i32 1, i32 2}
; CHECK: !3 = metadata !{metadata !"branch_weights", i32 49, i32 12, i32 24, i32 35}
; CHECK: !4 = metadata !{metadata !"branch_weights", i32 11, i32 5}
; CHECK: !5 = metadata !{metadata !"branch_weights", i32 17, i32 15}
; CHECK: !6 = metadata !{metadata !"branch_weights", i32 9, i32 7}
; CHECK: !7 = metadata !{metadata !"branch_weights", i32 17, i32 9, i32 8, i32 7, i32 17}
; CHECK: !8 = metadata !{metadata !"branch_weights", i32 24, i32 33}
; CHECK: !9 = metadata !{metadata !"branch_weights", i32 8, i32 33}
; CHECK-NOT: !9
|
