Methods and systems for executing SIMD instructions that efficiently implement new SIMD instructions and conventional existing SIMD MAC-type instructions, while avoiding replication of functions in order to keep the size of the logic circuit size to as low a level as can reasonably be achieved. An instruction unit executes Single Instruction Multiple Data instructions, including instructions acting on operands representing complex numbers. The instruction unit includes functional blocks that are commonly utilized to execute a plurality of the instructions, wherein the plurality of instructions utilize various individual functional blocks in various combinations with one another. The plurality of instructions is optionally executed in a pipeline fashion.