Function cubeRoot

deps/opencv/modules/core/src/mathfuncs.cpp:159–194

\ Fast cube root by Ken Turkowski (http://www.worldserver.com/turk/computergraphics/papers.html) \* ************************************************************************** */

   (http://www.worldserver.com/turk/computergraphics/papers.html)
\* ************************************************************************** */
float  cubeRoot( float value )
{
    float fr;
    Cv32suf v, m;
    int ix, s;
    int ex, shx;

    v.f = value;
    ix = v.i & 0x7fffffff;
    s = v.i & 0x80000000;
    ex = (ix >> 23) - 127;
    shx = ex % 3;
    shx -= shx >= 0 ? 3 : 0;
    ex = (ex - shx) / 3; /* exponent of cube root */
    v.i = (ix & ((1<<23)-1)) | ((shx + 127)<<23);
    fr = v.f;

    /* 0.125 <= fr < 1.0 */
    /* Use quartic rational polynomial with error < 2^(-24) */
    fr = (float)(((((45.2548339756803022511987494 * fr +
    192.2798368355061050458134625) * fr +
    119.1654824285581628956914143) * fr +
    13.43250139086239872172837314) * fr +
    0.1636161226585754240958355063)/
    ((((14.80884093219134573786480845 * fr +
    151.9714051044435648658557668) * fr +
    168.5254414101568283957668343) * fr +
    33.9905941350215598754191872) * fr +
    1.0));

    /* fr *= 2^ex * sign */
    m.f = value;
    v.f = fr;
    v.i = (v.i + (ex << 23) + s) & (m.i*2 != 0 ? -1 : 0);
    return v.f;
}

static void Magnitude_32f(const float* x, const float* y, float* mag, int len)
{