Efficient canonical form for Boolean matching of complex functions in large libraries

A new algorithm is developed which transforms the truth table or implicant table of a Boolean function into a canonical form under any permutation of inputs. The algorithm is used for Boolean matching for large libraries that contain cells with large numbers of inputs and implicants. The minimum cost canonical form is used as a unique identifier for searching for the cell in the library. The search time is nearly constant if a hash table is used for storing the cells´ canonical representations in the library. Experimental results on more than 100,000 gates confirm the validity and feasible run-time of the algorithm.