x2 = number * 0.5F;
y = number;
i = * ( __int64 * ) &y;
i = 0x5fe6ec85e7de30da - ( i >> 1 );
y = * ( double * ) &i;
y = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration
y = y * ( threehalfs - ( x2 * y * y ) ); // 2nd iteration, this can be removed
return y;
}
double d = 4.0000;
d = d*InvSqrt(d);