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
|
// SPDX-License-Identifier: GPL-2.0
#include <kunit/test.h>
#include <linux/mean_and_variance.h>
#define MAX_SQR (SQRT_U64_MAX*SQRT_U64_MAX)
static void mean_and_variance_basic_test(struct kunit *test)
{
struct mean_and_variance s = {};
s = mean_and_variance_update(s, 2);
s = mean_and_variance_update(s, 2);
KUNIT_EXPECT_EQ(test, mean_and_variance_get_mean(s), 2);
KUNIT_EXPECT_EQ(test, mean_and_variance_get_variance(s), 0);
KUNIT_EXPECT_EQ(test, s.n, 2);
s = mean_and_variance_update(s, 4);
s = mean_and_variance_update(s, 4);
KUNIT_EXPECT_EQ(test, mean_and_variance_get_mean(s), 3);
KUNIT_EXPECT_EQ(test, mean_and_variance_get_variance(s), 1);
KUNIT_EXPECT_EQ(test, s.n, 4);
/*
* Test overflow bounds
*/
s = (struct mean_and_variance){};
s = mean_and_variance_update(s, SQRT_U64_MAX);
KUNIT_EXPECT_EQ_MSG(test,
s.sum_squares.lo,
MAX_SQR,
"%llu == %llu, sqrt: %llu == %llu",
s.sum_squares.lo,
MAX_SQR,
int_sqrt64(s.sum_squares.lo),
SQRT_U64_MAX);
s = (struct mean_and_variance){};
s = mean_and_variance_update(s, -(s64)SQRT_U64_MAX);
KUNIT_EXPECT_EQ_MSG(test,
s.sum_squares.lo,
MAX_SQR,
"%llu == %llu, sqrt: %llu == %llu",
s.sum_squares.lo,
MAX_SQR,
int_sqrt64(s.sum_squares.lo),
SQRT_U64_MAX);
s = (struct mean_and_variance){};
s = mean_and_variance_update(s, (SQRT_U64_MAX + 1));
KUNIT_EXPECT_EQ(test, s.sum_squares.lo, MAX_SQR);
s = (struct mean_and_variance){};
s = mean_and_variance_update(s, (-(s64)SQRT_U64_MAX) - 1);
KUNIT_EXPECT_EQ(test, s.sum_squares.lo, MAX_SQR);
}
/*
* Test values computed using a spreadsheet from the psuedocode at the bottom:
* https://fanf2.user.srcf.net/hermes/doc/antiforgery/stats.pdf
*/
static void mean_and_variance_weighted_test(struct kunit *test)
{
struct mean_and_variance_weighted s = {};
s.w = 2;
s = mean_and_variance_weighted_update(s, 10);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), 10);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 0);
s = mean_and_variance_weighted_update(s, 20);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), 12);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 18);
s = mean_and_variance_weighted_update(s, 30);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), 16);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 71);
s = (struct mean_and_variance_weighted){};
s.w = 2;
s = mean_and_variance_weighted_update(s, -10);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), -10);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 0);
s = mean_and_variance_weighted_update(s, -20);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), -12);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 18);
s = mean_and_variance_weighted_update(s, -30);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), -16);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 71);
}
static void mean_and_variance_weighted_advanced_test(struct kunit *test)
{
struct mean_and_variance_weighted s = {};
s64 i;
s.w = 8;
for (i = 10; i <= 100; i += 10)
s = mean_and_variance_weighted_update(s, i);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), 11);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 107);
s = (struct mean_and_variance_weighted){};
s.w = 8;
for (i = -10; i >= -100; i -= 10)
s = mean_and_variance_weighted_update(s, i);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_mean(s), -11);
KUNIT_EXPECT_EQ(test, mean_and_variance_weighted_get_variance(s), 107);
}
static void mean_and_variance_fast_divpow2(struct kunit *test)
{
s64 i;
u8 d;
for (i = 0; i < 100; i++) {
d = 0;
KUNIT_EXPECT_EQ(test, fast_divpow2(i, d), div_u64(i, 1LLU << d));
KUNIT_EXPECT_EQ(test, abs(fast_divpow2(-i, d)), div_u64(i, 1LLU << d));
for (d = 1; d < 32; d++) {
KUNIT_EXPECT_EQ_MSG(test, abs(fast_divpow2(i, d)),
div_u64(i, 1 << d), "%lld %u", i, d);
KUNIT_EXPECT_EQ_MSG(test, abs(fast_divpow2(-i, d)),
div_u64(i, 1 << d), "%lld %u", -i, d);
}
}
}
static void mean_and_variance_u128_test(struct kunit *test)
{
u128 a = u128_init(0, U64_MAX);
u128 a0 = u128_init(0, 0);
u128 a1 = u128_init(0, 1);
u128 a2 = u128_init(0, 2);
u128 b = u128_init(1, 0);
u128 c = u128_init(0, 1LLU << 63);
KUNIT_EXPECT_EQ(test, u128_add(a,a1).hi, 1);
KUNIT_EXPECT_EQ(test, u128_add(a,a1).lo, 0);
KUNIT_EXPECT_EQ(test, u128_sub(b,a1).lo, U64_MAX);
KUNIT_EXPECT_EQ(test, u128_sub(b,a1).hi, 0);
KUNIT_EXPECT_EQ(test, u128_shl(c, 1).hi, 1 );
KUNIT_EXPECT_EQ(test, u128_shl(c, 1).lo, 0 );
KUNIT_EXPECT_EQ(test, u128_square(1).hi, 0);
KUNIT_EXPECT_EQ(test, u128_square(1).lo, 1);
KUNIT_EXPECT_EQ(test, u128_square(0).hi, 0);
KUNIT_EXPECT_EQ(test, u128_square(0).lo, 0);
KUNIT_EXPECT_EQ(test, u128_square(2).lo, 4);
KUNIT_EXPECT_EQ(test, u128_square(U64_MAX).hi, U64_MAX);
KUNIT_EXPECT_EQ(test, u128_square(U64_MAX).lo, 1);
KUNIT_EXPECT_EQ(test, u128_div(b, 2).lo, 1LLU << 63);
}
static struct kunit_case mean_and_variance_test_cases[] = {
KUNIT_CASE(mean_and_variance_fast_divpow2),
KUNIT_CASE(mean_and_variance_u128_test),
KUNIT_CASE(mean_and_variance_basic_test),
KUNIT_CASE(mean_and_variance_weighted_test),
KUNIT_CASE(mean_and_variance_weighted_advanced_test),
{}
};
static struct kunit_suite mean_and_variance_test_suite = {
.name = "mean and variance tests",
.test_cases = mean_and_variance_test_cases
};
kunit_test_suite(mean_and_variance_test_suite);
|
