Techniques are described which decrease DRC (design rule check) marking
time, e.g., in a circuit interconnect router, by capitalizing on
repetitious relationships between interconnect elements (and/or circuit
components) in a circuit design, by recording previously calculated
markings and reusing the markings on subsequent marking iterations or
processes. Marking information corresponding to each marking point
includes indications of what types of interconnect elements or circuit
components can be positioned at the marking point location without
violating a design rule. With a dynamic caching process, once the marking
computations have been completed for an element and the corresponding
points in the vicinity, those values are stored in a cache. The next time
the router encounters another instance of a known element-to-point
relationship, the stored values are reloaded and applied to the current
point.