About 9 years ago, Notch was working on a sub-project called DCPU-16 for a game he later abanodned called 0x10^c. At the time, he was taking suggestions for opcodes, so I posted a suggestion:
https://www.reddit.com/r/dcpu16/comments/ssdny/hcf_opcode_use_sparingly/
Notch replied:
Fast-forward 9 years later:
https://twitter.com/inertia186/status/1397083580551942151
- inertia186
https://twitter.com/inertia186/status/1397095211369594886
- inertia186
To this day, you can still find the opcode in the more complete implementations, along with my helpful documentation:
https://github.com/bartman/0x10c-tools/blob/master/include/dcpu_def.h#L53