Identifying high-level components in combinational circuits

The problem of finding meaningful subcircuits in a logic layout appears in many contexts in computer-aided design. Existing techniques rely upon finding exact matchings of subcircuit structure within the layout. These syntactic techniques fail to identify functionally equivalent subcircuits which are differently implemented optimized, or otherwise obfuscated. We present a mechanism for identifying functionally equivalent subcircuits which is capable of overcoming many of these limitations. Such semantic matching is particularly useful in the field of design recovery.