A Succinct and Efficient Implementation of a 2^32 BDD Package

As a data structure for representing and manipulating Boolean functions, BDDs (Binary Decision Diagrams) are commonly used in many fields such as model-checking, system verification and so on. For saving space and improving operation speed, all the existing packages limit the number of variables to 216. However, such a limitation also restrains its applicability. In this paper, we present TiniBDD, an efficient implementation of a 232 BDD package incorporating sub-allocation of memory and lightweight Garbage Collection as well as a new operator named as Satisfiable Assignment Operator. Compared with the well-known CUDD which is one of the best 216 BDD packages that can be attained publicly, the experiments show TiniBDD has comparable performance.