xref: /openbmc/linux/lib/math/rational-test.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <kunit/test.h>
4 
5 #include <linux/rational.h>
6 
7 struct rational_test_param {
8 	unsigned long num, den;
9 	unsigned long max_num, max_den;
10 	unsigned long exp_num, exp_den;
11 
12 	const char *name;
13 };
14 
15 static const struct rational_test_param test_parameters[] = {
16 	{ 1230,	10,	100, 20,	100, 1,    "Exceeds bounds, semi-convergent term > 1/2 last term" },
17 	{ 34567,100, 	120, 20,	120, 1,    "Exceeds bounds, semi-convergent term < 1/2 last term" },
18 	{ 1, 30,	100, 10,	0, 1,	   "Closest to zero" },
19 	{ 1, 19,	100, 10,	1, 10,     "Closest to smallest non-zero" },
20 	{ 27,32,	16, 16,		11, 13,    "Use convergent" },
21 	{ 1155, 7735,	255, 255,	33, 221,   "Exact answer" },
22 	{ 87, 32,	70, 32,		68, 25,    "Semiconvergent, numerator limit" },
23 	{ 14533, 4626,	15000, 2400,	7433, 2366, "Semiconvergent, denominator limit" },
24 };
25 
26 static void get_desc(const struct rational_test_param *param, char *desc)
27 {
28 	strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
29 }
30 
31 /* Creates function rational_gen_params */
32 KUNIT_ARRAY_PARAM(rational, test_parameters, get_desc);
33 
34 static void rational_test(struct kunit *test)
35 {
36 	const struct rational_test_param *param = (const struct rational_test_param *)test->param_value;
37 	unsigned long n = 0, d = 0;
38 
39 	rational_best_approximation(param->num, param->den, param->max_num, param->max_den, &n, &d);
40 	KUNIT_EXPECT_EQ(test, n, param->exp_num);
41 	KUNIT_EXPECT_EQ(test, d, param->exp_den);
42 }
43 
44 static struct kunit_case rational_test_cases[] = {
45 	KUNIT_CASE_PARAM(rational_test, rational_gen_params),
46 	{}
47 };
48 
49 static struct kunit_suite rational_test_suite = {
50 	.name = "rational",
51 	.test_cases = rational_test_cases,
52 };
53 
54 kunit_test_suites(&rational_test_suite);
55 
56 MODULE_LICENSE("GPL v2");
57