Re: Why is Elisp slow?

[Stefan Monnier]

>>>    Why can't Elisp be compiled as well?
>> The question is meaningless because it's premise is wrong: Elisp can
>> be compiled as well.
> I’m pretty sure Elisp can’t compile down to raw machine code (like JIT) in
> current infrastructure.

Maybe there is no compiler that does that currently, but that's not
relevant to the question of whether there can be such a compiler.
[ And FWIW, you can probably compile Elisp to "raw" machine code with
  https://sourceforge.net/p/clocc/hg/ci/default/tree/src/cllib/elisp.lisp  ]

> Elisp bytecode is terribly slow :-(

There's been very little effort put into making it fast, indeed.
This said, when we compared it to Guile and some byte-code-based
Common-Lisp (I think it was ECL, but I can't remember) some years ago it
wasn't nearly as bad as I thought.

If someone's interested in speeding it up.  I'd recommend two
approaches:
- Either a JIT based on something like basic-block-versioning (BBV)
- Or a fast byte-code such as those generated by vmgen


        Stefan