Reversible logic synthesis based on a modified tabulation method

An important property of reversible circuits is that they can reduce the energy consumption which is now a big problem for the advanced circuit design. If a circuit is reversible, it can reduce the energy consumption caused by information loss. The tabulation method is more efficient than other simplification methods for combination logic circuits. But the classical tabulation method is not directly applicable to reversible circuits because the basic logic gates, except the NOT gate, are not reversible gates. In this paper, we propose a method to solve the problem so that the tabulation method can be applied to the reversible circuit synthesis. Our algorithm provides a systematic method to simplify the reversible circuit. This can produce the resulting expression in exclusive-sum form and transform it into a final reversible circuit with lower quantum cost. Moreover, we can realize permutations to be reversible circuits with lower quantum cost and without unnecessary garbage bits. We can also convert irreversible circuits by adding qubits to make the circuits reversible. The experimental results show that the average saving in quantum cost is 15.82% compared with previous approaches.