1. One or more non-transitory computer-readable media storing computer-executable instructions for causing one or more processors to perform a method, the method comprising: receiving information of a circuit design; analyzing the circuit design to derive information of memory-circuit device groups, each of the memory-circuit device groups having at least two instances in the circuit design, the memory-circuit device groups comprising word-line-driven device groups; if the circuit design is hierarchically structured, flattening the circuit design while keeping instances of the memory-circuit device groups intact; partitioning the circuit design into a plurality of subcircuits; and simulating the circuit design based on the plurality of subcircuits, wherein the simulating comprises: determining whether instances of the word-line-driven device groups are activated, an instance of a word-line-driven device group being activated if at least one input port of the instance is activated; associating, for an inactivated instance of a word-line-driven device group, inactivated device model values for the word-line-driven device group with the inactivated instance; determining, for an activated instance of a word-line-driven device group, whether activated device model values exist for the word-line-driven device group at a voltage state associated with the activated instance; if the activated device model values exist for the word-line-driven device group at the voltage state, associating the activated device model values with the activated instance; if the activated device model values do not exist for the word-line-driven device group at the voltage state, computing the activated device model values, associating the computed activated device model values with the activated instance, and storing the computed activated device model values for the word-line-driven device group at the voltage state.