source: asp3_tinet_ecnl_arm/trunk/musl-1.1.18/src/math/hypotf.c@ 352

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

float hypotf(float x, float y)
{
        union {float f; uint32_t i;} ux = {x}, uy = {y}, ut;
        float_t z;

        ux.i &= -1U>>1;
        uy.i &= -1U>>1;
        if (ux.i < uy.i) {
                ut = ux;
                ux = uy;
                uy = ut;
        }

        x = ux.f;
        y = uy.f;
        if (uy.i == 0xff<<23)
                return y;
        if (ux.i >= 0xff<<23 || uy.i == 0 || ux.i - uy.i >= 25<<23)
                return x + y;

        z = 1;
        if (ux.i >= (0x7f+60)<<23) {
                z = 0x1p90f;
                x *= 0x1p-90f;
                y *= 0x1p-90f;
        } else if (uy.i < (0x7f-60)<<23) {
                z = 0x1p-90f;
                x *= 0x1p90f;
                y *= 0x1p90f;
        }
        return z*sqrtf((double)x*x + (double)y*y);
}