1. A method of adding reconfigurable computational instructions to a reduced instruction set computer, the method comprising the steps of: loading a computer program into a memory accessible by a processor core of the reduced instruction set computer, the computer program containing at least one instruction extension not native to an instruction set of the processor core; detecting that the computer program contains the instruction extension; configuring a programmable logic device to execute the instruction extension; and executing the instruction extension on the programmable logic device for use by the processor core in processing the computer program.