def RotL_64(x, N):
 return (np.left_shift(x, (N & 63), dtype=np.uint64) | np.right_shift(x, ((64 - N) & 63), dtype=np.uint64))

def RotL_64 ( x , N ) : return ( np . left_shift ( x , ( N & 63 ) , dtype = np . uint64 ) | np . right_shift ( x , ( ( 64 - N ) & 63 ) , dtype = np . uint64 ) )
return x rotated left by n .