Methods and software are presented for processing data in a programmable processor, involving (a) decoding instructions for execution using an execution unit operable to execute instructions by partitioning data stored in registers in a register file into multiple data elements, the instructions selected from an instruction set that includes group arithmetic instructions and group data handling instructions, (b) in response to decoding different group data handling instructions, executing group data handling operations that re-arrange data elements in different ways, and (c) in response to decoding different group arithmetic instructions, executing a plurality of different group floating-point and group integer arithmetic operations that each arithmetically operates on the multiple data elements stored in registers in the register file to produce a catenated result that is returned to a register in the register file, wherein the catenated result comprises a plurality of individual results.