Re: master 289000e: Merge branch 'feature/native-comp' into trunk

[Alan Mackenzie]

Hello, Óscar.

On Mon, Apr 26, 2021 at 17:33:30 +0200, Óscar Fuentes wrote:
> Alan Mackenzie <acm@muc.de> writes:

> > I must be doing something differently from these people, but I can't
> > identify what.  Native compilation just doesn't seem to be working for
> > me, yet.  How much of a speed up should it give me?  Surely more than 5%
> > - 10%?

> native-comp speeds up Elisp, and even then there are lots of cases where
> the change is hardly noticeable.

> Let's say your code spends 90% on the C core and 10% on Elisp. If
> native-comp brings a 2x speed up, you'll only observe about 5%
> improvement.

It seems something like that is indeed happening.

> C code is opaque to native-comp and puts a hard limit on how much it can
> optimize Elisp. Thus I hope that in the future more and more code will
> be moved from C to Elisp.

Does that make sense?  To move time critical code from fast C to slow
Lisp, and then optimise it back, partly?

> And other areas can benefit too: one thing which IMO has lots of
> potential is to native-compile regexps.

Again, how would that work?  Regexps are already handled in C.  How
could native compilation of Lisp add anything?

-- 
Alan Mackenzie (Nuremberg, Germany).