Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>

/*
 * floating-point mod function without infinity or NaN checking
 */
double
fmod (double x, double y)
{
        int sign, yexp, rexp;
        double r, yfr, rfr;

        if (y == 0)
                return x;
        if (y < 0)
                y = -y;
        yfr = frexp(y, &yexp);
        sign = 0;
        if(x < 0) {
                r = -x;
                sign++;
        } else
                r = x;
        while(r >= y) {
                rfr = frexp(r, &rexp);
                r -= ldexp(y, rexp - yexp - (rfr < yfr));
        }
        if(sign)
                r = -r;
        return r;
}