#include <math.h>
#include <stdint.h>

float fmodf(float x, float y) {
    union {
        float f;
        uint32_t i;
    } ux = {x}, uy = {y};
    int ex = ux.i >> 23 & 0xff;
    int ey = uy.i >> 23 & 0xff;
    uint32_t sx = ux.i & 0x80000000;
    uint32_t i;
    uint32_t uxi = ux.i;

    if (uy.i << 1 == 0 || isnan(y) || ex == 0xff)
        return (x * y) / (x * y);
    if (uxi << 1 <= uy.i << 1) {
        if (uxi << 1 == uy.i << 1)
            return 0 * x;
        return x;
    }

    /* normalize x and y */
    if (!ex) {
        for (i = uxi << 9; i >> 31 == 0; ex--, i <<= 1)
            ;
        uxi <<= -ex + 1;
    } else {
        uxi &= -1U >> 9;
        uxi |= 1U << 23;
    }
    if (!ey) {
        for (i = uy.i << 9; i >> 31 == 0; ey--, i <<= 1)
            ;
        uy.i <<= -ey + 1;
    } else {
        uy.i &= -1U >> 9;
        uy.i |= 1U << 23;
    }

    /* x mod y */
    for (; ex > ey; ex--) {
        i = uxi - uy.i;
        if (i >> 31 == 0) {
            if (i == 0)
                return 0 * x;
            uxi = i;
        }
        uxi <<= 1;
    }
    i = uxi - uy.i;
    if (i >> 31 == 0) {
        if (i == 0)
            return 0 * x;
        uxi = i;
    }
    for (; uxi >> 23 == 0; uxi <<= 1, ex--)
        ;

    /* scale result up */
    if (ex > 0) {
        uxi -= 1U << 23;
        uxi |= (uint32_t)ex << 23;
    } else {
        uxi >>= -ex + 1;
    }
    uxi |= sx;
    ux.i = uxi;
    return ux.f;
}