Two Novel Multiway Circuit PartitioningAlgorithmsUsing Relaxed

All the previous Kernighan-Lin (KL) based circuit partitioning algorithms employ the locking mechanism, which enforces each cell to be moved exactly once per pass. In this paper, we propose two novel approaches for multiway circuit partitioning to overcome this limitation. The proposed approaches are based on our claim that the performance of a KL{based partitioning algorithm gets better by allowing each cell to be moved more than once per pass. The rst approach uses the locking mechanism in a relaxed manner. It allows multiple moves for each cell in a pass by introducing the phase concept so that each pass can contain more than one phase, and each cell has a chance to be moved only once in each phase. The second approach does not use the locking mechanism at all. It introduces the mobility concept, which allows a cell to be moved as many times per pass as possible based on its mobility values. Each approach leads to a KL based generic algorithm whose parameters can be set in such a way that better performance is obtained by spending more time. By setting these parameters, we generated three versions of each generic algorithm. The performance of the proposed algorithms was experimentally evaluated in comparison with Sanchis' multiway circuit partitioning algorithm (FMS algorithm) and the simulated annealing algorithm (SA algorithm) on benchmark circuits. The proposed algorithms outperform FMS algorithm signi cantly especially on the partitioning of sparse circuits and partitioning into more than two parts. Their performance is comparable to that of SA algorithm though they are much faster than SA algorithm. This paper also provides guidelines for good parameter settings for the generic algorithms, and presents a new formulation of multiway circuit partitioning that combines those of the previous approaches.