Signature based duplicate extraction

A computer system for producing integrated circuit design files by electronic design automation with optimizations including the removal of duplicate gates from a computer representation of a circuit design, comprising:

• a processor;
• first program code storage coupled to said processor and comprising stored instructions directing the execution of said processor for identifying a first gate from a plurality of gates of a stored circuit design as a current gate;
• second program code storage coupled to said processor and comprising stored instructions directing the execution of said processor for determining a signature value dependent on one or more attributes of said current gate and corresponding to a signature table slot;
• and
• third program code storage coupled to said processor and comprising stored instructions directing the execution of said processor for determining whether a prior gate is associated with said signature table slot and,
• if not, associating said current gate with said signature table slot, and,
• if so, comparing said current gate with said prior gate, and modifying said stored circuit design to consolidate said prior gate and said current gate if said comparing indicates duplication, otherwise associating said current gate with said signature table slot.