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9#include <linux/rational.h>
10#include <linux/module.h>
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29void rational_best_approximation(
30 unsigned long given_numerator, unsigned long given_denominator,
31 unsigned long max_numerator, unsigned long max_denominator,
32 unsigned long *best_numerator, unsigned long *best_denominator)
33{
34 unsigned long n, d, n0, d0, n1, d1;
35 n = given_numerator;
36 d = given_denominator;
37 n0 = d1 = 0;
38 n1 = d0 = 1;
39 for (;;) {
40 unsigned long t, a;
41 if ((n1 > max_numerator) || (d1 > max_denominator)) {
42 n1 = n0;
43 d1 = d0;
44 break;
45 }
46 if (d == 0)
47 break;
48 t = d;
49 a = n / d;
50 d = n % d;
51 n = t;
52 t = n0 + a * n1;
53 n0 = n1;
54 n1 = t;
55 t = d0 + a * d1;
56 d0 = d1;
57 d1 = t;
58 }
59 *best_numerator = n1;
60 *best_denominator = d1;
61}
62
63EXPORT_SYMBOL(rational_best_approximation);
64