float Q_rsqrt( float number )

{

 long i;

 float x2, y;

 const float threehalfs = 1.5F;

 x2 = number * 0.5F;

 y  = number;

 i  = * ( long * ) &y;      // evil floating point bit level hacking

 i  = 0x5f3759df - ( i >>  );               // what the fuck?

 y  = * ( float * ) &i;

 y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration

// y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed

#ifndef Q3_VM

#ifdef __linux__

 assert( !isnan(y) ); // bk010122 - FPE?

#endif

#endif

 return y;

}