#include <math.h>

float fmaxf(float x, float y)
{
    if (isnan(x))
        return y;
    if (isnan(y))
        return x;
    /* handle signed zeroes, see C99 Annex F.9.9.2 */
    if (signbit(x) != signbit(y))
        return signbit(x) ? y : x;
    return x < y ? y : x;
}
