docs: function copysign( x, y ) {
  	var hx;
  	var hy;
  
  	// Split `x` into higher and lower order words:
  	x = toWords( x );
  	hx = x[ 0 ];
  
  	// Turn off the sign bit of `x`:
  	hx &= MAGNITUDE_MASK;
  
  	// Extract the higher order word from `y`:
  	hy = getHighWord( y );
  
  	// Leave only the sign bit of `y` turned on:
  	hy &= SIGN_MASK;
  
  	// Copy the sign bit of `y` to `x`:
  	hx |= hy;
  
  	// Return a new value having the same magnitude as `x`, but with the sign of `y`:
  	return fromWords( hx, x[ 1 ] );
  }