unsigned int isqrt32(unsigned int x)
{	
	unsigned int x1;
	int s, g0, g1;
	if (x <= 1) return x;
	s = 1;
	x1 = x - 1;
	if (x1 > 65535) { s+=8; x1>>=16;}
	if (x1 > 255)   { s+=4; x1>>=8;}
	if (x1 > 15)    { s+=2; x1>>=4;}
	if (x1 > 3)     { s+=1; }
	g0 = 1<<s;

	g1 = (g0 + (x >> s)) >> 1;
	while(g1 < g0)
	{
		g0 = g1;
		g1 = (g0 + (x/g0)) >> 1;
	}
	return g0;
}