1. An arithmetic logic system for performing arithmetic and logical functions on a plurality of input signals comprising: input signal means for receiving a plurality of input signals; a first arithmetic logic means, coupled to the input signal means, for performing arithmetic and logic functions on the input signals; a second arithmetic logic means connected for receiving output signals from the first arithmetic logic means, for performing arithmetic and logic functions on the output signals from the first arithmetic logic means; and control means, coupled to the first and second arithmetic logic means, for controlling the operation of the second arithmetic logic means in response to the output signals from the first arithmetic logic means.