source: asp3_tinet_ecnl_rx/trunk/musl-1.1.18/src/math/fdim.c@ 337

#include <math.h>

double fdim(double x, double y)
{
        if (isnan(x))
                return x;
        if (isnan(y))
                return y;
        return x > y ? x - y : 0;
}