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
|
; RUN: opt < %s -basic-aa -licm -S | FileCheck %s
; RUN: opt -aa-pipeline=basic-aa -passes='require<aa>,require<targetir>,require<scalar-evolution>,require<opt-remark-emit>,loop(licm)' -S %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Make sure we don't hoist the store out of the loop; %a would
; have the wrong value if f() unwinds
define void @test1(i32* nocapture noalias %a, i1 zeroext %y) uwtable {
entry:
br label %for.body
for.body:
%i.03 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
%0 = load i32, i32* %a, align 4
%add = add nsw i32 %0, 1
store i32 %add, i32* %a, align 4
br i1 %y, label %if.then, label %for.inc
; CHECK: define void @test1
; CHECK: load i32, i32*
; CHECK-NEXT: add
; CHECK-NEXT: store i32
if.then:
tail call void @f()
br label %for.inc
for.inc:
%inc = add nuw nsw i32 %i.03, 1
%exitcond = icmp eq i32 %inc, 10000
br i1 %exitcond, label %for.cond.cleanup, label %for.body
for.cond.cleanup:
ret void
}
; We can hoist the store out of the loop here; if f() unwinds,
; the lifetime of %a ends.
define void @test2(i1 zeroext %y) uwtable {
entry:
%a = alloca i32
br label %for.body
for.body:
%i.03 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
%0 = load i32, i32* %a, align 4
%add = add nsw i32 %0, 1
store i32 %add, i32* %a, align 4
br i1 %y, label %if.then, label %for.inc
if.then:
tail call void @f()
br label %for.inc
for.inc:
%inc = add nuw nsw i32 %i.03, 1
%exitcond = icmp eq i32 %inc, 10000
br i1 %exitcond, label %for.cond.cleanup, label %for.body
for.cond.cleanup:
; CHECK: define void @test2
; CHECK: store i32
; CHECK-NEXT: ret void
ret void
}
;; We can promote if the load can be proven safe to speculate, and the
;; store safe to sink, even if the the store *isn't* must execute.
define void @test3(i1 zeroext %y) uwtable {
; CHECK-LABEL: @test3
entry:
; CHECK-LABEL: entry:
; CHECK-NEXT: %a = alloca i32
; CHECK-NEXT: %a.promoted = load i32, i32* %a, align 4
%a = alloca i32
br label %for.body
for.body:
%i.03 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%0 = load i32, i32* %a, align 4
%add = add nsw i32 %0, 1
tail call void @f()
store i32 %add, i32* %a, align 4
%inc = add nuw nsw i32 %i.03, 1
%exitcond = icmp eq i32 %inc, 10000
br i1 %exitcond, label %for.cond.cleanup, label %for.body
for.cond.cleanup:
; CHECK-LABEL: for.cond.cleanup:
; CHECK: store i32 %add.lcssa, i32* %a, align 4
; CHECK-NEXT: ret void
ret void
}
;; Same as test3, but with unordered atomics
define void @test3b(i1 zeroext %y) uwtable {
; CHECK-LABEL: @test3
entry:
; CHECK-LABEL: entry:
; CHECK-NEXT: %a = alloca i32
; CHECK-NEXT: %a.promoted = load atomic i32, i32* %a unordered, align 4
%a = alloca i32
br label %for.body
for.body:
%i.03 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%0 = load atomic i32, i32* %a unordered, align 4
%add = add nsw i32 %0, 1
tail call void @f()
store atomic i32 %add, i32* %a unordered, align 4
%inc = add nuw nsw i32 %i.03, 1
%exitcond = icmp eq i32 %inc, 10000
br i1 %exitcond, label %for.cond.cleanup, label %for.body
for.cond.cleanup:
; CHECK-LABEL: for.cond.cleanup:
; CHECK: store atomic i32 %add.lcssa, i32* %a unordered, align 4
; CHECK-NEXT: ret void
ret void
}
@_ZTIi = external constant i8*
; In this test, the loop is within a try block. There is an explicit unwind edge out of the loop.
; Make sure this edge is treated as a loop exit, and that the loads and stores are promoted as
; expected
define void @loop_within_tryblock() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
entry:
%a = alloca i32, align 4
store i32 0, i32* %a, align 4
br label %for.cond
for.cond:
%i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
%cmp = icmp slt i32 %i.0, 1024
br i1 %cmp, label %for.body, label %for.end
; CHECK: for.body:
; CHECK-NOT: load
; CHECK-NOT: store
; CHECK: invoke
for.body:
%0 = load i32, i32* %a, align 4
%add = add nsw i32 %0, 1
store i32 %add, i32* %a, align 4
invoke void @boo()
to label %invoke.cont unwind label %lpad
invoke.cont:
br label %for.inc
for.inc:
%inc = add nsw i32 %i.0, 1
br label %for.cond
; CHECK: lpad:
; CHECK: store
; CHECK: br
lpad:
%1 = landingpad { i8*, i32 }
catch i8* bitcast (i8** @_ZTIi to i8*)
%2 = extractvalue { i8*, i32 } %1, 0
%3 = extractvalue { i8*, i32 } %1, 1
br label %catch.dispatch
catch.dispatch:
%4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) #3
%matches = icmp eq i32 %3, %4
br i1 %matches, label %catch, label %eh.resume
catch:
%5 = call i8* @__cxa_begin_catch(i8* %2) #3
%6 = bitcast i8* %5 to i32*
%7 = load i32, i32* %6, align 4
call void @__cxa_end_catch() #3
br label %try.cont
try.cont:
ret void
for.end:
br label %try.cont
eh.resume:
%lpad.val = insertvalue { i8*, i32 } undef, i8* %2, 0
%lpad.val3 = insertvalue { i8*, i32 } %lpad.val, i32 %3, 1
resume { i8*, i32 } %lpad.val3
}
; The malloc'ed memory is not capture and therefore promoted.
define void @malloc_no_capture() #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
entry:
%call = call i8* @malloc(i64 4)
%0 = bitcast i8* %call to i32*
br label %for.body
; CHECK: for.body:
; CHECK-NOT: load
; CHECK-NOT: store
; CHECK: br
for.body:
%i.0 = phi i32 [ 0, %entry ], [ %inc, %for.latch ]
%1 = load i32, i32* %0, align 4
%add = add nsw i32 %1, 1
store i32 %add, i32* %0, align 4
br label %for.call
for.call:
invoke void @boo()
to label %invoke.cont unwind label %lpad
invoke.cont:
br label %for.latch
for.latch:
%inc = add i32 %i.0, 1
%cmp = icmp slt i32 %i.0, 1024
br i1 %cmp, label %for.body, label %for.end
for.end:
br label %fun.ret
lpad:
%2 = landingpad { i8*, i32 }
catch i8* null
%3 = extractvalue { i8*, i32 } %2, 0
%4 = extractvalue { i8*, i32 } %2, 1
br label %catch
catch:
%5 = call i8* @__cxa_begin_catch(i8* %3) #4
%6 = bitcast i32* %0 to i8*
call void @free(i8* %6)
call void @__cxa_end_catch()
br label %fun.ret
fun.ret:
ret void
}
; The malloc'ed memory can be captured and therefore not promoted.
define void @malloc_capture(i32** noalias %A) personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
entry:
%call = call i8* @malloc(i64 4)
%0 = bitcast i8* %call to i32*
br label %for.body
; CHECK: for.body:
; CHECK: load
; CHECK: store
; CHECK: br
for.body:
%i.0 = phi i32 [ 0, %entry ], [ %inc, %for.latch ]
%1 = load i32, i32* %0, align 4
%add = add nsw i32 %1, 1
store i32 %add, i32* %0, align 4
br label %for.call
for.call:
invoke void @boo_readnone()
to label %invoke.cont unwind label %lpad
invoke.cont:
br label %for.latch
for.latch:
store i32* %0, i32** %A
%inc = add i32 %i.0, 1
%cmp = icmp slt i32 %i.0, 1024
br i1 %cmp, label %for.body, label %for.end
for.end:
br label %fun.ret
lpad:
%2 = landingpad { i8*, i32 }
catch i8* null
%3 = extractvalue { i8*, i32 } %2, 0
%4 = extractvalue { i8*, i32 } %2, 1
br label %catch
catch:
%5 = call i8* @__cxa_begin_catch(i8* %3) #4
%6 = bitcast i32* %0 to i8*
call void @free(i8* %6)
call void @__cxa_end_catch()
br label %fun.ret
fun.ret:
ret void
}
; Function Attrs: nounwind
declare noalias i8* @malloc(i64)
; Function Attrs: nounwind
declare void @free(i8* nocapture)
declare void @boo()
; This is an artifical example, readnone functions by definition cannot unwind
; exceptions by calling the C++ exception throwing methods
; This function should only be used to test malloc_capture.
declare void @boo_readnone() readnone
declare i32 @__gxx_personality_v0(...)
declare i8* @__cxa_begin_catch(i8*)
declare void @__cxa_end_catch()
declare i32 @llvm.eh.typeid.for(i8*)
declare void @f() uwtable
|
