A process for the determination of addresses in variable length addressing

Abstract

An algorithm is presented for the assignment of instruction addresses and formats under the following conditions: (1) the length of the instruction varies as a function of the distance of the instruction from its target; (2) there exists an optimality criterion which implies some preferential choices subject to the addressing constraints. This may be, for example, achieving the smallest number of long instructions, in which case the total code length is minimized, or minimizing the assigned address of a specified point in the program. The algorithm is suitable for arbitrary program structure and a choice of optimization criteria.