tripcount.ll
7.65 KB
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
; This test verifies that the loop vectorizer will not vectorizes low trip count
; loops that require runtime checks (Trip count is computed with profile info).
; REQUIRES: asserts
; RUN: opt < %s -loop-vectorize -loop-vectorize-with-block-frequency -S | FileCheck %s
target datalayout = "E-m:e-p:32:32-i64:32-f64:32:64-a:0:32-n32-S128"
@tab = common global [32 x i8] zeroinitializer, align 1
define i32 @foo_low_trip_count1(i32 %bound) {
; Simple loop with low tripcount. Should not be vectorized.
; CHECK-LABEL: @foo_low_trip_count1(
; CHECK-NOT: <{{[0-9]+}} x i8>
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 1
%exitcond = icmp eq i32 %i.08, %bound
br i1 %exitcond, label %for.end, label %for.body, !prof !1
for.end: ; preds = %for.body
ret i32 0
}
define i32 @foo_low_trip_count2(i32 %bound) !prof !0 {
; The loop has a same invocation count with the function, but has a low
; trip_count per invocation and not worth to vectorize.
; CHECK-LABEL: @foo_low_trip_count2(
; CHECK-NOT: <{{[0-9]+}} x i8>
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 1
%exitcond = icmp eq i32 %i.08, %bound
br i1 %exitcond, label %for.end, label %for.body, !prof !1
for.end: ; preds = %for.body
ret i32 0
}
define i32 @foo_low_trip_count3(i1 %cond, i32 %bound) !prof !0 {
; The loop has low invocation count compare to the function invocation count,
; but has a high trip count per invocation. Vectorize it.
; CHECK-LABEL: @foo_low_trip_count3(
; CHECK: [[VECTOR_BODY:vector\.body]]:
; CHECK: br i1 [[TMP9:%.*]], label [[MIDDLE_BLOCK:%.*]], label %[[VECTOR_BODY]], !prof [[LP3:\!.*]],
; CHECK: [[FOR_BODY:for\.body]]:
; CHECK: br i1 [[EXITCOND:%.*]], label [[FOR_END_LOOPEXIT:%.*]], label %[[FOR_BODY]], !prof [[LP6:\!.*]],
entry:
br i1 %cond, label %for.preheader, label %for.end, !prof !2
for.preheader:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 1
%exitcond = icmp eq i32 %i.08, %bound
br i1 %exitcond, label %for.end, label %for.body, !prof !3
for.end: ; preds = %for.body
ret i32 0
}
define i32 @foo_low_trip_count_icmp_sgt(i32 %bound) {
; Simple loop with low tripcount and inequality test for exit.
; Should not be vectorized.
; CHECK-LABEL: @foo_low_trip_count_icmp_sgt(
; CHECK-NOT: <{{[0-9]+}} x i8>
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 1
%exitcond = icmp sgt i32 %i.08, %bound
br i1 %exitcond, label %for.end, label %for.body, !prof !1
for.end: ; preds = %for.body
ret i32 0
}
define i32 @const_low_trip_count() {
; Simple loop with constant, small trip count and no profiling info.
; CHECK-LABEL: @const_low_trip_count
; CHECK-NOT: <{{[0-9]+}} x i8>
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 1
%exitcond = icmp slt i32 %i.08, 2
br i1 %exitcond, label %for.body, label %for.end
for.end: ; preds = %for.body
ret i32 0
}
define i32 @const_large_trip_count() {
; Simple loop with constant large trip count and no profiling info.
; CHECK-LABEL: @const_large_trip_count
; CHECK: <{{[0-9]+}} x i8>
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 1
%exitcond = icmp slt i32 %i.08, 1000
br i1 %exitcond, label %for.body, label %for.end
for.end: ; preds = %for.body
ret i32 0
}
define i32 @const_small_trip_count_step() {
; Simple loop with static, small trip count and no profiling info.
; CHECK-LABEL: @const_small_trip_count_step
; CHECK-NOT: <{{[0-9]+}} x i8>
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 5
%exitcond = icmp slt i32 %i.08, 10
br i1 %exitcond, label %for.body, label %for.end
for.end: ; preds = %for.body
ret i32 0
}
define i32 @const_trip_over_profile() {
; constant trip count takes precedence over profile data
; CHECK-LABEL: @const_trip_over_profile
; CHECK: <{{[0-9]+}} x i8>
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%i.08 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @tab, i32 0, i32 %i.08
%0 = load i8, i8* %arrayidx, align 1
%cmp1 = icmp eq i8 %0, 0
%. = select i1 %cmp1, i8 2, i8 1
store i8 %., i8* %arrayidx, align 1
%inc = add nsw i32 %i.08, 1
%exitcond = icmp slt i32 %i.08, 1000
br i1 %exitcond, label %for.body, label %for.end, !prof !1
for.end: ; preds = %for.body
ret i32 0
}
; CHECK: [[LP3]] = !{!"branch_weights", i32 10, i32 2490}
; CHECK: [[LP6]] = !{!"branch_weights", i32 10, i32 0}
; original loop has latchExitWeight=10 and backedgeTakenWeight=10,000,
; therefore estimatedBackedgeTakenCount=1,000 and estimatedTripCount=1,001.
; Vectorizing by 4 produces estimatedTripCounts of 1,001/4=250 and 1,001%4=1
; for vectorized and remainder loops, respectively, therefore their
; estimatedBackedgeTakenCounts are 249 and 0, and so the weights recorded with
; loop invocation weights of 10 are the above {10, 2490} and {10, 0}.
!0 = !{!"function_entry_count", i64 100}
!1 = !{!"branch_weights", i32 100, i32 0}
!2 = !{!"branch_weights", i32 10, i32 90}
!3 = !{!"branch_weights", i32 10, i32 10000}