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
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
|
; RUN: opt < %s -S -loop-unroll -verify-loop-info | FileCheck %s
;
; Unit tests for LoopInfo::updateUnloop.
declare i1 @check() nounwind
; Ensure that tail->inner is removed and rely on verify-loopinfo to
; check soundness.
;
; CHECK: @skiplevelexit
; CHECK: tail:
; CHECK-NOT: br
; CHECK: ret void
define void @skiplevelexit() nounwind {
entry:
br label %outer
outer:
br label %inner
inner:
%iv = phi i32 [ 0, %outer ], [ %inc, %tail ]
%inc = add i32 %iv, 1
%wbucond = call zeroext i1 @check()
br i1 %wbucond, label %outer.backedge, label %tail
tail:
br i1 false, label %inner, label %exit
outer.backedge:
br label %outer
exit:
ret void
}
; Remove the middle loop of a triply nested loop tree.
; Ensure that only the middle loop is removed and rely on verify-loopinfo to
; check soundness.
;
; CHECK: @unloopNested
; Outer loop control.
; CHECK: while.body:
; CHECK: br i1 %cmp3, label %if.then, label %if.end
; Inner loop control.
; CHECK: while.end14.i:
; CHECK: br i1 %call15.i, label %if.end.i, label %exit
; Middle loop control should no longer reach %while.cond.
; Now it is the outer loop backedge.
; CHECK: exit:
; CHECK: br label %while.cond.outer
define void @unloopNested() {
entry:
br label %while.cond.outer
while.cond.outer:
br label %while.cond
while.cond:
%cmp = call zeroext i1 @check()
br i1 %cmp, label %while.body, label %while.end
while.body:
%cmp3 = call zeroext i1 @check()
br i1 %cmp3, label %if.then, label %if.end
if.then:
br label %return
if.end:
%cmp.i48 = call zeroext i1 @check()
br i1 %cmp.i48, label %if.then.i, label %if.else20.i
if.then.i:
%cmp8.i = call zeroext i1 @check()
br i1 %cmp8.i, label %merge, label %if.else.i
if.else.i:
br label %merge
if.else20.i:
%cmp25.i = call zeroext i1 @check()
br i1 %cmp25.i, label %merge, label %if.else28.i
if.else28.i:
br label %merge
merge:
br label %while.cond2.i
while.cond2.i:
%cmp.i = call zeroext i1 @check()
br i1 %cmp.i, label %while.cond2.backedge.i, label %while.end.i
while.cond2.backedge.i:
br label %while.cond2.i
while.end.i:
%cmp1114.i = call zeroext i1 @check()
br i1 %cmp1114.i, label %while.body12.lr.ph.i, label %while.end14.i
while.body12.lr.ph.i:
br label %while.end14.i
while.end14.i:
%call15.i = call zeroext i1 @check()
br i1 %call15.i, label %if.end.i, label %exit
if.end.i:
br label %while.cond2.backedge.i
exit:
br i1 false, label %while.cond, label %if.else
if.else:
br label %while.cond.outer
while.end:
br label %return
return:
ret void
}
; Remove the middle loop of a deeply nested loop tree.
; Ensure that only the middle loop is removed and rely on verify-loopinfo to
; check soundness.
;
; CHECK: @unloopDeepNested
; Inner-inner loop control.
; CHECK: while.cond.us.i:
; CHECK: br i1 %cmp.us.i, label %next_data.exit, label %while.body.us.i
; CHECK: if.then.us.i:
; CHECK: br label %while.cond.us.i
; Inner loop tail.
; CHECK: if.else.i:
; CHECK: br label %while.cond.outer.i
; Middle loop control (removed).
; CHECK: valid_data.exit:
; CHECK-NOT: br
; CHECK: %cmp = call zeroext i1 @check()
; Outer loop control.
; CHECK: copy_data.exit:
; CHECK: br i1 %cmp38, label %if.then39, label %while.cond.outer
; Outer-outer loop tail.
; CHECK: while.cond.outer.outer.backedge:
; CHECK: br label %while.cond.outer.outer
define void @unloopDeepNested() nounwind {
for.cond8.preheader.i:
%cmp113.i = call zeroext i1 @check()
br i1 %cmp113.i, label %make_data.exit, label %for.body13.lr.ph.i
for.body13.lr.ph.i:
br label %make_data.exit
make_data.exit:
br label %while.cond.outer.outer
while.cond.outer.outer:
br label %while.cond.outer
while.cond.outer:
br label %while.cond
while.cond:
br label %while.cond.outer.i
while.cond.outer.i:
%tmp192.ph.i = call zeroext i1 @check()
br i1 %tmp192.ph.i, label %while.cond.outer.split.us.i, label %while.body.loopexit
while.cond.outer.split.us.i:
br label %while.cond.us.i
while.cond.us.i:
%cmp.us.i = call zeroext i1 @check()
br i1 %cmp.us.i, label %next_data.exit, label %while.body.us.i
while.body.us.i:
%cmp7.us.i = call zeroext i1 @check()
br i1 %cmp7.us.i, label %if.then.us.i, label %if.else.i
if.then.us.i:
br label %while.cond.us.i
if.else.i:
br label %while.cond.outer.i
next_data.exit:
%tmp192.ph.i.lcssa28 = call zeroext i1 @check()
br i1 %tmp192.ph.i.lcssa28, label %while.end, label %while.body
while.body.loopexit:
br label %while.body
while.body:
br label %while.cond.i
while.cond.i:
%cmp.i = call zeroext i1 @check()
br i1 %cmp.i, label %valid_data.exit, label %while.body.i
while.body.i:
%cmp7.i = call zeroext i1 @check()
br i1 %cmp7.i, label %valid_data.exit, label %if.end.i
if.end.i:
br label %while.cond.i
valid_data.exit:
br i1 true, label %if.then, label %while.cond
if.then:
%cmp = call zeroext i1 @check()
br i1 %cmp, label %if.then12, label %if.end
if.then12:
br label %if.end
if.end:
%tobool3.i = call zeroext i1 @check()
br i1 %tobool3.i, label %copy_data.exit, label %while.body.lr.ph.i
while.body.lr.ph.i:
br label %copy_data.exit
copy_data.exit:
%cmp38 = call zeroext i1 @check()
br i1 %cmp38, label %if.then39, label %while.cond.outer
if.then39:
%cmp5.i = call zeroext i1 @check()
br i1 %cmp5.i, label %while.cond.outer.outer.backedge, label %for.cond8.preheader.i8.thread
for.cond8.preheader.i8.thread:
br label %while.cond.outer.outer.backedge
while.cond.outer.outer.backedge:
br label %while.cond.outer.outer
while.end:
ret void
}
; Remove a nested loop with irreducible control flow.
; Ensure that only the middle loop is removed and rely on verify-loopinfo to
; check soundness.
;
; CHECK: @unloopIrreducible
; Irreducible loop.
; CHECK: for.inc117:
; CHECK: br label %for.cond103t
; Nested loop (removed).
; CHECK: for.inc159:
; CHECK: br label %for.inc163
define void @unloopIrreducible() nounwind {
entry:
br label %for.body
for.body:
%cmp2113 = call zeroext i1 @check()
br i1 %cmp2113, label %for.body22.lr.ph, label %for.inc163
for.body22.lr.ph:
br label %for.body22
for.body22:
br label %for.body33
for.body33:
br label %for.end
for.end:
%cmp424 = call zeroext i1 @check()
br i1 %cmp424, label %for.body43.lr.ph, label %for.end93
for.body43.lr.ph:
br label %for.end93
for.end93:
%cmp96 = call zeroext i1 @check()
br i1 %cmp96, label %if.then97, label %for.cond103
if.then97:
br label %for.cond103t
for.cond103t:
br label %for.cond103
for.cond103:
%cmp105 = call zeroext i1 @check()
br i1 %cmp105, label %for.body106, label %for.end120
for.body106:
%cmp108 = call zeroext i1 @check()
br i1 %cmp108, label %if.then109, label %for.inc117
if.then109:
br label %for.inc117
for.inc117:
br label %for.cond103t
for.end120:
br label %for.inc159
for.inc159:
br i1 false, label %for.body22, label %for.cond15.for.inc163_crit_edge
for.cond15.for.inc163_crit_edge:
br label %for.inc163
for.inc163:
%cmp12 = call zeroext i1 @check()
br i1 %cmp12, label %for.body, label %for.end166
for.end166:
ret void
}
; Remove a loop whose exit branches into a sibling loop.
; Ensure that only the loop is removed and rely on verify-loopinfo to
; check soundness.
;
; CHECK: @unloopCriticalEdge
; CHECK: while.cond.outer.i.loopexit.split:
; CHECK: br label %while.body
; CHECK: while.body:
; CHECK: br label %for.end78
define void @unloopCriticalEdge() nounwind {
entry:
br label %for.cond31
for.cond31:
br i1 undef, label %for.body35, label %for.end94
for.body35:
br label %while.cond.i.preheader
while.cond.i.preheader:
br i1 undef, label %while.cond.i.preheader.split, label %while.cond.outer.i.loopexit.split
while.cond.i.preheader.split:
br label %while.cond.i
while.cond.i:
br i1 true, label %while.cond.i, label %while.cond.outer.i.loopexit
while.cond.outer.i.loopexit:
br label %while.cond.outer.i.loopexit.split
while.cond.outer.i.loopexit.split:
br i1 false, label %while.cond.i.preheader, label %Func2.exit
Func2.exit:
br label %while.body
while.body:
br i1 false, label %while.body, label %while.end
while.end:
br label %for.end78
for.end78:
br i1 undef, label %Proc2.exit, label %for.cond.i.preheader
for.cond.i.preheader:
br label %for.cond.i
for.cond.i:
br label %for.cond.i
Proc2.exit:
br label %for.cond31
for.end94:
ret void
}
; Test UnloopUpdater::removeBlocksFromAncestors.
;
; Check that the loop backedge is removed from the middle loop 1699,
; but not the inner loop 1676.
; CHECK: while.body1694:
; CHECK: br label %while.cond1676
; CHECK: while.end1699:
; CHECK: br label %sw.default1711
define void @removeSubloopBlocks() nounwind {
entry:
br label %tryagain.outer
tryagain.outer: ; preds = %sw.bb304, %entry
br label %tryagain
tryagain: ; preds = %while.end1699, %tryagain.outer
br i1 undef, label %sw.bb1669, label %sw.bb304
sw.bb304: ; preds = %tryagain
br i1 undef, label %return, label %tryagain.outer
sw.bb1669: ; preds = %tryagain
br i1 undef, label %sw.default1711, label %while.cond1676
while.cond1676: ; preds = %while.body1694, %sw.bb1669
br i1 undef, label %while.end1699, label %while.body1694
while.body1694: ; preds = %while.cond1676
br label %while.cond1676
while.end1699: ; preds = %while.cond1676
br i1 false, label %tryagain, label %sw.default1711
sw.default1711: ; preds = %while.end1699, %sw.bb1669, %tryagain
br label %defchar
defchar: ; preds = %sw.default1711, %sw.bb376
br i1 undef, label %if.end2413, label %if.then2368
if.then2368: ; preds = %defchar
unreachable
if.end2413: ; preds = %defchar
unreachable
return: ; preds = %sw.bb304
ret void
}
|
