diff options
Diffstat (limited to 'lib/math/rational.c')
| -rw-r--r-- | lib/math/rational.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/lib/math/rational.c b/lib/math/rational.c index 31fb27db2deb..ec59d426ea63 100644 --- a/lib/math/rational.c +++ b/lib/math/rational.c @@ -11,7 +11,9 @@ #include <linux/rational.h> #include <linux/compiler.h> #include <linux/export.h> -#include <linux/kernel.h> +#include <linux/minmax.h> +#include <linux/limits.h> +#include <linux/module.h> /* * calculate best rational approximation for a given fraction @@ -27,7 +29,7 @@ * with the fractional part size described in given_denominator. * * for theoretical background, see: - * http://en.wikipedia.org/wiki/Continued_fraction + * https://en.wikipedia.org/wiki/Continued_fraction */ void rational_best_approximation( @@ -78,13 +80,18 @@ void rational_best_approximation( * found below as 't'. */ if ((n2 > max_numerator) || (d2 > max_denominator)) { - unsigned long t = min((max_numerator - n0) / n1, - (max_denominator - d0) / d1); + unsigned long t = ULONG_MAX; - /* This tests if the semi-convergent is closer - * than the previous convergent. + if (d1) + t = (max_denominator - d0) / d1; + if (n1) + t = min(t, (max_numerator - n0) / n1); + + /* This tests if the semi-convergent is closer than the previous + * convergent. If d1 is zero there is no previous convergent as this + * is the 1st iteration, so always choose the semi-convergent. */ - if (2u * t > a || (2u * t == a && d0 * dp > d1 * d)) { + if (!d1 || 2u * t > a || (2u * t == a && d0 * dp > d1 * d)) { n1 = n0 + t * n1; d1 = d0 + t * d1; } @@ -100,3 +107,5 @@ void rational_best_approximation( } EXPORT_SYMBOL(rational_best_approximation); + +MODULE_LICENSE("GPL v2"); |