Fast detection of node mergers using logic implications

In this paper, we propose a new node merging algorithm using logic implications. The proposed algorithm only requires two logic implications to find the substitute nodes for a given target node, and thus can efficiently detect node mergers. Furthermore, we also apply the node merger identification algorithm for area optimization in VLSI circuits. We conduct experiments on a set of IWLS 2005 benchmarks. The experimental results show that our algorithm has a competitive capability on area optimization compared to a global observability don't care (ODC)-based node merging algorithm which is highly time-consuming. Our speedup is approximately 86 times for overall benchmarks.