lc3-vm VS Papers

I haven't read the whole article yet, I just want to report what seems to be a small error:

> The code is written in C11, and it will probably compile on most operating systems. The repo can be found here, and the exact source code is vm.c:

The link on "here" is broken, it's https://github.com/,nomemory/lc3-vm (with a comma before your github username) instead of (I think) https://github.com/nomemory/lc3-vm.

What are you talking about?. The full implementation is even smaller: https://github.com/nomemory/lc3-vm/blob/main/vm.c

Further to this: this kind of thing is something the Forth community takes seriously. They call these threaded code techniques. [0] (The Gforth interpreter, for instance, gives you the choice of various different techniques.)

Anton Ertl of Gforth fame published a microbenchmark performance comparison of toy interpreters, written in C, run on various CPUs. [1] As you say, the approach using function pointers (call threading) scores poorly.

Interestingly, direct threading and indirect threading are extremely close, with the winner seeming to depend on the specific CPU. [1] Branch-prediction differences seem to be the main reason. There was a 2001 paper on this. [2]

[0] https://www.complang.tuwien.ac.at/forth/threaded-code.html

[1] https://www.complang.tuwien.ac.at/forth/threading/

[2] https://github.com/ForthPapersMirror/Papers/blob/master/Conv...