Optimizing performance of instructions based on sequence detection or information associated with the instructions

In one embodiment, the present invention includes an instruction decoder that can receive an incoming instruction and a path select signal and decode the incoming instruction into a first instruction code or a second instruction code responsive to the path select signal. The two different instruction codes, both representing the same incoming instruction may be used by an execution unit to perform an operation optimized for different data lengths. Other embodiments are described and claimed.