Alu with auxiliary units for pre and post processing of operands and immediate value within same instruction cycle

An arithmetic and logic device as an integral part of a processing unit is provided to achieve code size and overhead reduction. The arithmetic and logic device contains several auxiliary computing units, each of which is capable of simple arithmetic and logical operation, under the control of a control unit. By configuring the auxiliary computing units along the data path, additional processing to the operands could be carried out within the same instruction cycle. As such, a processing unit incorporating such an arithmetic and logic device is able to achieve significant performance improvement both in terms of code size and memory access overhead.