A method, system and product comprising: obtaining a functional-level representation of a quantum circuit that comprises a functional block, wherein the functional block defines an operation of the quantum circuit over at least two cycles; selecting from a function library an implementation for the functional block, wherein the function library comprises a plurality of alternative implementations of the functional block, wherein each implementation of the plurality of alternative implementations is configured to provide a same functionality of the functional block and is applicable to a quantum computer to be used for executing the quantum circuit; and generating a gate-level representation of the quantum circuit that comprises the implementation for the functional block.