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
|
; RUN: opt < %s -passes=newgvn -S | FileCheck %s
%struct.A = type { ptr }
@_ZTV1A = available_externally unnamed_addr constant [3 x ptr] [ptr null, ptr @_ZTI1A, ptr @_ZN1A3fooEv], align 8
@_ZTI1A = external constant ptr
@unknownPtr = external global i8
; CHECK-LABEL: define i8 @simple() {
define i8 @simple() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr, !invariant.group !0
call void @foo(ptr %ptr)
%a = load i8, ptr %ptr, !invariant.group !0
%b = load i8, ptr %ptr, !invariant.group !0
%c = load i8, ptr %ptr, !invariant.group !0
; CHECK: ret i8 42
ret i8 %a
}
; CHECK-LABEL: define i8 @optimizable1() {
define i8 @optimizable1() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr, !invariant.group !0
%ptr2 = call ptr @llvm.launder.invariant.group.p0(ptr %ptr)
%a = load i8, ptr %ptr, !invariant.group !0
call void @foo(ptr %ptr2); call to use %ptr2
; CHECK: ret i8 42
ret i8 %a
}
; CHECK-LABEL: define i8 @optimizable2() {
define i8 @optimizable2() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr, !invariant.group !0
call void @foo(ptr %ptr)
store i8 13, ptr %ptr ; can't use this store with invariant.group
%a = load i8, ptr %ptr
call void @bar(i8 %a) ; call to use %a
call void @foo(ptr %ptr)
%b = load i8, ptr %ptr, !invariant.group !0
; CHECK: ret i8 42
ret i8 %b
}
; CHECK-LABEL: define i1 @proveEqualityForStrip(
define i1 @proveEqualityForStrip(ptr %a) {
%b1 = call ptr @llvm.strip.invariant.group.p0(ptr %a)
; CHECK-NOT: llvm.strip.invariant.group
%b2 = call ptr @llvm.strip.invariant.group.p0(ptr %a)
%r = icmp eq ptr %b1, %b2
; CHECK: ret i1 true
ret i1 %r
}
; CHECK-LABEL: define i8 @unoptimizable1() {
define i8 @unoptimizable1() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr
call void @foo(ptr %ptr)
%a = load i8, ptr %ptr, !invariant.group !0
; CHECK: ret i8 %a
ret i8 %a
}
; NewGVN doesn't support assumes.
; CHECK-LABEL: define void @indirectLoads() {
define void @indirectLoads() {
entry:
%a = alloca ptr, align 8
%call = call ptr @getPointer(ptr null)
call void @_ZN1AC1Ev(ptr %call)
; CHECK: %vtable = load {{.*}} !invariant.group
%vtable = load ptr, ptr %call, align 8, !invariant.group !0
%cmp.vtables = icmp eq ptr %vtable, getelementptr inbounds ([3 x ptr], ptr @_ZTV1A, i64 0, i64 2)
call void @llvm.assume(i1 %cmp.vtables)
store ptr %call, ptr %a, align 8
%0 = load ptr, ptr %a, align 8
; FIXME: call void @_ZN1A3fooEv(
%vtable1 = load ptr, ptr %0, align 8, !invariant.group !0
%1 = load ptr, ptr %vtable1, align 8
call void %1(ptr %0)
%2 = load ptr, ptr %a, align 8
; FIXME: call void @_ZN1A3fooEv(
%vtable2 = load ptr, ptr %2, align 8, !invariant.group !0
%3 = load ptr, ptr %vtable2, align 8
call void %3(ptr %2)
%4 = load ptr, ptr %a, align 8
%vtable4 = load ptr, ptr %4, align 8, !invariant.group !0
%5 = load ptr, ptr %vtable4, align 8
; FIXME: call void @_ZN1A3fooEv(
call void %5(ptr %4)
%vtable5 = load ptr, ptr %call, align 8, !invariant.group !0
%6 = load ptr, ptr %vtable5, align 8
; FIXME: call void @_ZN1A3fooEv(
call void %6(ptr %4)
ret void
}
; NewGVN won't CSE loads with different pointee types.
; CHECK-LABEL: define void @combiningBitCastWithLoad() {
define void @combiningBitCastWithLoad() {
entry:
%a = alloca ptr, align 8
%call = call ptr @getPointer(ptr null)
call void @_ZN1AC1Ev(ptr %call)
; CHECK: %vtable = load {{.*}} !invariant.group
%vtable = load ptr, ptr %call, align 8, !invariant.group !0
%cmp.vtables = icmp eq ptr %vtable, getelementptr inbounds ([3 x ptr], ptr @_ZTV1A, i64 0, i64 2)
store ptr %call, ptr %a, align 8
; FIXME-NOT: !invariant.group
%0 = load ptr, ptr %a, align 8
%vtable1 = load ptr, ptr %0, align 8, !invariant.group !0
%1 = load ptr, ptr %vtable1, align 8
call void %1(ptr %0)
ret void
}
; CHECK-LABEL:define void @loadCombine() {
define void @loadCombine() {
enter:
%ptr = alloca i8
store i8 42, ptr %ptr
call void @foo(ptr %ptr)
; CHECK: %[[A:.*]] = load i8, ptr %ptr, align 1, !invariant.group
%a = load i8, ptr %ptr, !invariant.group !0
; CHECK-NOT: load
%b = load i8, ptr %ptr, !invariant.group !0
; CHECK: call void @bar(i8 %[[A]])
call void @bar(i8 %a)
; CHECK: call void @bar(i8 %[[A]])
call void @bar(i8 %b)
ret void
}
; CHECK-LABEL: define void @loadCombine1() {
define void @loadCombine1() {
enter:
%ptr = alloca i8
store i8 42, ptr %ptr
call void @foo(ptr %ptr)
; CHECK: %[[D:.*]] = load i8, ptr %ptr, align 1, !invariant.group
%c = load i8, ptr %ptr
; CHECK-NOT: load
%d = load i8, ptr %ptr, !invariant.group !0
; CHECK: call void @bar(i8 %[[D]])
call void @bar(i8 %c)
; CHECK: call void @bar(i8 %[[D]])
call void @bar(i8 %d)
ret void
}
; CHECK-LABEL: define void @loadCombine2() {
define void @loadCombine2() {
enter:
%ptr = alloca i8
store i8 42, ptr %ptr
call void @foo(ptr %ptr)
; CHECK: %[[E:.*]] = load i8, ptr %ptr, align 1, !invariant.group
%e = load i8, ptr %ptr, !invariant.group !0
; CHECK-NOT: load
%f = load i8, ptr %ptr
; CHECK: call void @bar(i8 %[[E]])
call void @bar(i8 %e)
; CHECK: call void @bar(i8 %[[E]])
call void @bar(i8 %f)
ret void
}
; CHECK-LABEL: define void @loadCombine3() {
define void @loadCombine3() {
enter:
%ptr = alloca i8
store i8 42, ptr %ptr
call void @foo(ptr %ptr)
; CHECK: %[[E:.*]] = load i8, ptr %ptr, align 1, !invariant.group
%e = load i8, ptr %ptr, !invariant.group !0
; CHECK-NOT: load
%f = load i8, ptr %ptr, !invariant.group !0
; CHECK: call void @bar(i8 %[[E]])
call void @bar(i8 %e)
; CHECK: call void @bar(i8 %[[E]])
call void @bar(i8 %f)
ret void
}
; CHECK-LABEL: define i8 @unoptimizable2() {
define i8 @unoptimizable2() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr
call void @foo(ptr %ptr)
%a = load i8, ptr %ptr
call void @foo(ptr %ptr)
%b = load i8, ptr %ptr, !invariant.group !0
; CHECK: ret i8 %a
ret i8 %a
}
; CHECK-LABEL: define i8 @unoptimizable3() {
define i8 @unoptimizable3() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr, !invariant.group !0
%ptr2 = call ptr @getPointer(ptr %ptr)
%a = load i8, ptr %ptr2, !invariant.group !0
; CHECK: ret i8 %a
ret i8 %a
}
; NewGVN cares about the launder for some reason.
; CHECK-LABEL: define i8 @optimizable4() {
define i8 @optimizable4() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr
%ptr2 = call ptr @llvm.launder.invariant.group.p0(ptr %ptr)
; FIXME-NOT: load
%a = load i8, ptr %ptr2
; FIXME: ret i8 42
ret i8 %a
}
; CHECK-LABEL: define i8 @volatile1() {
define i8 @volatile1() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr, !invariant.group !0
call void @foo(ptr %ptr)
%a = load i8, ptr %ptr, !invariant.group !0
%b = load volatile i8, ptr %ptr
; CHECK: call void @bar(i8 %b)
call void @bar(i8 %b)
%c = load volatile i8, ptr %ptr, !invariant.group !0
; We might be able to optimize this, but nobody cares
; CHECK: call void @bar(i8 %c)
call void @bar(i8 %c)
; CHECK: ret i8 42
ret i8 %a
}
; CHECK-LABEL: define i8 @volatile2() {
define i8 @volatile2() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr, !invariant.group !0
call void @foo(ptr %ptr)
%a = load i8, ptr %ptr, !invariant.group !0
%b = load volatile i8, ptr %ptr
; CHECK: call void @bar(i8 %b)
call void @bar(i8 %b)
%c = load volatile i8, ptr %ptr, !invariant.group !0
; We might be able to optimize this, but nobody cares
; CHECK: call void @bar(i8 %c)
call void @bar(i8 %c)
; CHECK: ret i8 42
ret i8 %a
}
; CHECK-LABEL: define void @fun() {
define void @fun() {
entry:
%ptr = alloca i8
store i8 42, ptr %ptr, !invariant.group !0
call void @foo(ptr %ptr)
%a = load i8, ptr %ptr, !invariant.group !0 ; Can assume that value under %ptr didn't change
; CHECK: call void @bar(i8 42)
call void @bar(i8 %a)
ret void
}
; FIXME: NewGVN doesn't run instsimplify on a load from a vtable definition?
; This test checks if invariant.group understands gep with zeros
; CHECK-LABEL: define void @testGEP0() {
define void @testGEP0() {
%a = alloca %struct.A, align 8
store ptr getelementptr inbounds ([3 x ptr], ptr @_ZTV1A, i64 0, i64 2), ptr %a, align 8, !invariant.group !0
; CHECK: call void @_ZN1A3fooEv(ptr nonnull dereferenceable(8) %a)
call void @_ZN1A3fooEv(ptr nonnull dereferenceable(8) %a) ; This call may change vptr
%1 = load i8, ptr @unknownPtr, align 4
%2 = icmp eq i8 %1, 0
br i1 %2, label %_Z1gR1A.exit, label %3
; This should be devirtualized by invariant.group
%4 = load ptr, ptr %a, align 8, !invariant.group !0
%5 = load ptr, ptr %4, align 8
; FIXME: call void @_ZN1A3fooEv(ptr nonnull %a)
call void %5(ptr nonnull %a)
br label %_Z1gR1A.exit
_Z1gR1A.exit: ; preds = %0, %3
ret void
}
; Check if no optimizations are performed with global pointers.
; FIXME: we could do the optimizations if we would check if dependency comes
; from the same function.
; CHECK-LABEL: define void @testGlobal() {
define void @testGlobal() {
; CHECK: %a = load i8, ptr @unknownPtr, align 1, !invariant.group !0
%a = load i8, ptr @unknownPtr, !invariant.group !0
call void @foo2(ptr @unknownPtr, i8 %a)
; CHECK: %1 = load i8, ptr @unknownPtr, align 1, !invariant.group !0
%1 = load i8, ptr @unknownPtr, !invariant.group !0
call void @bar(i8 %1)
call void @fooBit(ptr @unknownPtr, i1 1)
; Adding regex because of canonicalization of bitcasts
; CHECK: %2 = load i1, ptr {{.*}}, !invariant.group !0
%2 = load i1, ptr @unknownPtr, !invariant.group !0
call void @fooBit(ptr @unknownPtr, i1 %2)
; CHECK: %3 = load i1, ptr {{.*}}, !invariant.group !0
%3 = load i1, ptr @unknownPtr, !invariant.group !0
call void @fooBit(ptr @unknownPtr, i1 %3)
ret void
}
; Might be similar to above where NewGVN doesn't handle loads of different types from the same location.
; Not super important anyway.
; CHECK-LABEL: define void @testTrunc() {
define void @testTrunc() {
%a = alloca i8
call void @foo(ptr %a)
; CHECK: %b = load i8, ptr %a, align 1, !invariant.group !0
%b = load i8, ptr %a, !invariant.group !0
call void @foo2(ptr %a, i8 %b)
%1 = load i8, ptr %a, !invariant.group !0
; CHECK: call void @bar(i8 %b)
call void @bar(i8 %1)
call void @fooBit(ptr %a, i1 1)
; FIXME: %1 = trunc i8 %b to i1
%2 = load i1, ptr %a, !invariant.group !0
; FIXME-NEXT: call void @fooBit(ptr %a, i1 %1)
call void @fooBit(ptr %a, i1 %2)
%3 = load i1, ptr %a, !invariant.group !0
; FIXME-NEXT: call void @fooBit(ptr %a, i1 %1)
call void @fooBit(ptr %a, i1 %3)
ret void
}
; See comment in @testGEP0 on what NewGVN is lacking.
; CHECK-LABEL: define void @handling_loops()
define void @handling_loops() {
%a = alloca %struct.A, align 8
store ptr getelementptr inbounds ([3 x ptr], ptr @_ZTV1A, i64 0, i64 2), ptr %a, align 8, !invariant.group !0
%1 = load i8, ptr @unknownPtr, align 4
%2 = icmp sgt i8 %1, 0
br i1 %2, label %.lr.ph.i, label %_Z2g2R1A.exit
.lr.ph.i: ; preds = %0
%3 = load i8, ptr @unknownPtr, align 4
%4 = icmp sgt i8 %3, 1
br i1 %4, label %._crit_edge.preheader, label %_Z2g2R1A.exit
._crit_edge.preheader: ; preds = %.lr.ph.i
br label %._crit_edge
._crit_edge: ; preds = %._crit_edge.preheader, %._crit_edge
%5 = phi i8 [ %7, %._crit_edge ], [ 1, %._crit_edge.preheader ]
%.pre = load ptr, ptr %a, align 8, !invariant.group !0
%6 = load ptr, ptr %.pre, align 8
; FIXME: call void @_ZN1A3fooEv(ptr nonnull %a)
call void %6(ptr nonnull %a) #3
; FIXME-NOT: call void %
%7 = add nuw nsw i8 %5, 1
%8 = load i8, ptr @unknownPtr, align 4
%9 = icmp slt i8 %7, %8
br i1 %9, label %._crit_edge, label %_Z2g2R1A.exit.loopexit
_Z2g2R1A.exit.loopexit: ; preds = %._crit_edge
br label %_Z2g2R1A.exit
_Z2g2R1A.exit: ; preds = %_Z2g2R1A.exit.loopexit, %.lr.ph.i, %0
ret void
}
declare void @foo(ptr)
declare void @foo2(ptr, i8)
declare void @bar(i8)
declare ptr @getPointer(ptr)
declare void @_ZN1A3fooEv(ptr)
declare void @_ZN1AC1Ev(ptr)
declare void @fooBit(ptr, i1)
declare ptr @llvm.launder.invariant.group.p0(ptr)
declare ptr @llvm.strip.invariant.group.p0(ptr)
; Function Attrs: nounwind
declare void @llvm.assume(i1 %cmp.vtables) #0
attributes #0 = { nounwind }
!0 = !{}
|
