Abstract-This paper proposes a fast algorithm for Boolean matching of completely specified Boolean functions. The algorithm is based on the NPN classification and can be applied on-the-fly to millions of small practical functions appearing in industrial designs, leading to runtime and memory reduction in logic synthesis and technology mapping. The algorithm is conceptually simpler, faster, and more scalable than previous work. An NPN class is a set of Boolean functions derived from each other by permuting and complementing the inputs, and complementing the output. Boolean matching determines whether two Boolean functions belong to the same NPN class. In the practical applications, Boolean matching is used to match a function against a library of functions whose implementation or other properties are known or have been pre-computed. AIG This paper presents two algorithms: a fast heuristic one and a slower nearly-exact one. They are compared against [8] believed to be state-of-the-art in Boolean matching on a large set of small practical functions derived from industrial designs. The conclusion is that the proposed heuristic algorithm is often faster without degrading quality, while a more elaborate nearly-exact algorithm computes fewer classes than [8] . Moreover, [8] cannot be applied to functions of more than 9 inputs, which limits its practicality. Meanwhile, the proposed algorithm scales to 16 variables and is therefore a better fit for cut-based logic synthesis and technology mapping. The rest of the paper is organized as follows: Section II contains relevant background. Section III describes the proposed three-step algorithm. Section IV shows experimental results. Section V concludes the paper.
The authors of REF proposed a fast Boolean function NPN classification using canonical forms, in which a Boolean function is represented by a truth table.
Fast Boolean matching based on NPN classification
2013 International Conference on Field-Programmable Technology (FPT)
2013 International Conference on Field-Programmable Technology (FPT)
Computer Science