Interesting. With java the just in time compiler starts to work, if you have iterated several thousand times over the same spot (java cmd line option -XX:CompileThreshold sets this, the default 10000 by default for hotspot server) Interesting if lua has a similar thing... have to learn more about it.
JITs are more-or-less portable now. Lua's, like most, probably came originally from some Javascript's. But of course they all trace back conceptually to HotSpot in the '90s. Even Guile Scheme is JITted now, though it probably shares no code with the others.
The term "JIT" is getting abused lately to describe what happens to users' eBPF code that runs in the Linux kernel, and Wasm that runs in browsers. In those, all types are known statically, code is compiled to a portable form offline, and transcribed to machine code before any execution, and none of the runtime instrumentation, analysis, and progressive rewriting occurs.
