Every year in December I get a hankering for some kind of Weird Systems Project. It's the season when I built my Forth machine, etc.

This year, I transcribed the Smalltalk-80 VM description from the Blue Book into Rust. I then started iterating on it, applying types and optimizations where they didn't fundamentally change the behavior. Things that let the VM skip runtime checks that the compiler can prove happened, etc.

So it's about 2-3x as fast now.

How fast? Well, when the books were published in 1983, a naive transcription of the interpreter often managed a few thousand bytecodes/sec, and 200k/sec was considered very good.

Mine is currently doing about 70M/s on my laptop.

Part of that is "computers got fast," but a lot of it is also "compilers got good."