Cleaning Up: Garbage-Free Reversible Circuits by Design Languages

Reversible logic is a computational model that ensure that no values are discarded or duplicated. This gives the connection to Landauer's principle if and only if the underlying circuits are garbage-free. This paper shows how to describe and implement garbage-free reversible logic circuits in an easy and concise way. We use two domain-specific languages that are designed to describe reversible logic at different levels and garbage-free methods to translate between these. This approach relies heavily on programming language technology that is known and used for conventional functional languages. Though the languages ensure reversibility of the logic descriptions, they are not guaranteed to be garbage-free. It is still an important task for the designer to find the correct embeddings.