Compression of embedded system programs

Embedded systems are often sensitive to space, weight, and cost considerations. Reducing the size of stored programs can significantly improve these factors. This paper discusses a program compression methodology based on existing processor architectures. The authors examine practical and theoretical measures for the maximum compression rate of a suite of programs across six modern architectures. The theoretical compression rate is reported in terms of the zeroth and first-order entropies, while the practical compression rate is reported in terms of the Huffman-encoded format of the proposed compression methodology and the GNU file compression utility, gzip. These experiments indicate that a practical increase of 15%-30% and a theoretical increase of over 100% in code density can be expected using the techniques examined. In addition, a novel, greedy, variable-length-to variable-length encoding algorithm is presented with preliminary results