Time- and Space-Efficient Evaluation of Sparse Boolean Functions in Embedded Software

The paper addresses software implementation of large sparse systems of Boolean functions. Fast evaluation of such functions with the smallest memory consumption is often required in embedded systems. A new heuristic method of obtaining compact representation of sparse Boolean functions in a form of linked tables is described that can be used for BDD minimization as well. Evaluation of Boolean functions reduces to multiple indirect memory accesses. The method is compared to other techniques like a walk through a BDD or a list search and is illustrated on examples. The presented method is flexible in making trade-offs between performance and memory consumption and may be thus useful for embedded microprocessor or microcontroller software.