In my opinion, medium integers from 64 through, say, 1024 or 2048 bits are a niche needing explicit treatment.
Please take a look at this library: http://www.mentor.com/esl/catapult/algorithmic
"Algorithmic C (AC) datatypes are a class-based C++ library that provides arbitrary-length integer, fixed-point and complex data types. They enable algorithm, system and hardware designers to precisely model bit-true behavior in C++ specifications while accelerating simulation speeds by 10-200x faster versus alternate datatypes."
I believe this is an example of the explicit treatment you are referring to. This is the best open source example of such that I know of.
Regards, Luke
Wow, Thanks Luke! That sure looks good based on the description. I will take a closer look later as time allows. Best regards, Chris.