A system for searching an input string for a number of regular expressions includes a search block and a compiler. The search block includes a plurality of content addressable memory (CAM) devices, wherein each of the CAM devices is differently configured to implement search operations for regular expressions having a unique level of complexity. The compiler is configured to determine the complexity level of each of the regular expressions, and is configured to store each regular expression in a selected one of the CAM devices according to its complexity level.