Technologies are described herein to implement an optimizer that receives portions of a quantum circuit; identifies, from within the received portions of the quantum circuit, a pattern of quantum gates to perform a quantum function; searches a library for a replacement pattern of quantum gates, which is also to perform the quantum function, for the identified pattern of quantum gates; determines that a quantum cost of the replacement pattern of quantum gates is lower than a quantum cost of the identified pattern of quantum gates; and replaces the identified pattern of quantum gates with the replacement pattern of quantum gates.