1. A method for converting a flat netlist into a hierarchical netlist, comprising: receiving the flat netlist; traversing the flat netlist in a bottom-up fashion, identifying isomorphic subcircuits in the flat netlist; creating a set of cross-coupling capacitor collections for storing information of cross-coupling capacitors; creating a set of net collections for storing information of isomorphic subcircuits; and traversing each hierarchical level of the hierarchical netlist in a top-down fashion, generating the hierarchical netlist using the set of net collections and the set of cross-coupling capacitor collections.