> Generally, trace compilation is a dead end and has been abandoned repeatedly.

JAX is a tracing compiler!

(I know, I know, it sits in an extremely different part of the problem space than TraceMonkey or LuaJIT. Still.)

Thanks, Ben. I admit I mostly think tracing is just a mind-expanding concept to learn about, even if history has proven it’s not very practical as an organizing principle. But as you say, I’d love to offer more context on “what actually seems to work” industrially.

The TraceMonkey paper was on my qual reading list, and my quals happened to be around the time TraceMonkey was ripped out of SpiderMonkey. I was talking with one of the developers at the time (I think it was Jason Orendorff?), who said that tracing just doesn't work out, but there was limited circumstances where he thought it might work out... but I've completely forgotten what those circumstances were.

Has LuaJIT been superseded?

Got any other recommended resources on building compilers?

Well, course numbers are regular enough that you can look up what the "intro compilers" course is: https://www.cs.cornell.edu/courses/cs4120/2026sp/?schedule

The short answer is that compilers is basically broken up into two courses, with the first course largely being the minimum necessary to build a compiler (lexing, parsing, codegen, register allocation), and the second course being how to build an optimizing compiler.

I have read TONS of material about it*, and none of that is part of the majority of that!

In fact, the "backend" be compiler or interpreter is nearly always left as "exercise to reader".

You can't imagine how much is left to be discovered, from how make a closure, track environment, do pattern matching, memory representation, etc.

EVERYTHING interesting is something you need to look for.

P.D: This only one of the years:https://gist.githubusercontent.com/mamcx/e1743571b9a1ea163a7...

I think a lot of the non-professionals start with parsing and do not get exposed to backend. I have read two books about interpreters/compilers and they don't touch the backend very much.

Maybe this is introductory for backend?