lib/math/rational-test.c

0001 // SPDX-License-Identifier: GPL-2.0
0002
0003 #include <kunit/test.h>
0004
0005 #include <linux/rational.h>
0006
0007 struct rational_test_param {
0008     unsigned long num, den;
0009     unsigned long max_num, max_den;
0010     unsigned long exp_num, exp_den;
0011
0012     const char *name;
0013 };
0014
0015 static const struct rational_test_param test_parameters[] = {
0016     { 1230, 10, 100, 20,    100, 1,    "Exceeds bounds, semi-convergent term > 1/2 last term" },
0017     { 34567,100,    120, 20,    120, 1,    "Exceeds bounds, semi-convergent term < 1/2 last term" },
0018     { 1, 30,    100, 10,    0, 1,      "Closest to zero" },
0019     { 1, 19,    100, 10,    1, 10,     "Closest to smallest non-zero" },
0020     { 27,32,    16, 16,     11, 13,    "Use convergent" },
0021     { 1155, 7735,   255, 255,   33, 221,   "Exact answer" },
0022     { 87, 32,   70, 32,     68, 25,    "Semiconvergent, numerator limit" },
0023     { 14533, 4626,  15000, 2400,    7433, 2366, "Semiconvergent, denominator limit" },
0024 };
0025
0026 static void get_desc(const struct rational_test_param *param, char *desc)
0027 {
0028     strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
0029 }
0030
0031 /* Creates function rational_gen_params */
0032 KUNIT_ARRAY_PARAM(rational, test_parameters, get_desc);
0033
0034 static void rational_test(struct kunit *test)
0035 {
0036     const struct rational_test_param *param = (const struct rational_test_param *)test->param_value;
0037     unsigned long n = 0, d = 0;
0038
0039     rational_best_approximation(param->num, param->den, param->max_num, param->max_den, &n, &d);
0040     KUNIT_EXPECT_EQ(test, n, param->exp_num);
0041     KUNIT_EXPECT_EQ(test, d, param->exp_den);
0042 }
0043
0044 static struct kunit_case rational_test_cases[] = {
0045     KUNIT_CASE_PARAM(rational_test, rational_gen_params),
0046     {}
0047 };
0048
0049 static struct kunit_suite rational_test_suite = {
0050     .name = "rational",
0051     .test_cases = rational_test_cases,
0052 };
0053
0054 kunit_test_suites(&rational_test_suite);
0055
0056 MODULE_LICENSE("GPL v2");