[Cryptography] Population Count (POPC) instruction

[Patrick Chkoreff]

Jerry Leichter wrote on 5/11/21 11:30 PM:

> And the “uselessness” of the instruction... well, maybe you can believe that if you don’t know some tricks for effective use of the machine. The 6600 was a word-addressed machine with 60 bit words. There were no byte-level operations. Efficient algorithms existed to operate on 10 (6-bit) characters in a word in parallel, and to do other similar things. Many of those use Popcount.

Ah, that takes me back.  I used a CDC 6600 at GA Tech back in '79.  At 
first it was all punch cards and line printer output delivered in bins, 
but then we got CRTs and it was a whole new world.


-- Patrick