Replying to infiniterand, a table of function pointers is going to generally have way more overhead than an indirect goto. An indirect goto is essentially a single assembly jump instruction. This is also often faster than a while loop plus switch since it is friendlier to the branch predictor.

I'm sure there's probably a reason for doing things this way, but it seems like that code would make more sense as a function pointer table and a series of functions. Was that not preferred for aesthetic reasons or for some specific technical reason?

Speed.

Your suggestion adds indirect memory access plus function call, for every instruction.

I've tried every other way I can think of, and nothing runs faster from my experience.