On variable ordering and decomposition type choice in OKFDDs

Abstract

We present methods for the construction of small ordered Kronecker functional decision diagrams (OKFDDs). OKFDDs are a generalization of ordered binary decision diagrams (OBDDs) and ordered functional decision diagrams (OFDDs) as well. Starting with an upper bound for the size of an OKFDD representing a tree like circuit, we develop different heuristics to find good variable orderings and decomposition types for OKFDDs representing two level and multi level circuits, respectively. Experimental results are presented to show the efficiency of our approaches.