Is compiling autoloads useful?

Is compiling autoloads useful?

[Roland Winkler]

The Makefile used by the rather old BBDB v2 compiles the file
with BBDB autoloads. Does such a step offer any advantage with a
recent version of GNU Emacs?

Thanks,

Roland

Re: Is compiling autoloads useful?

[Stefan Monnier]

> The Makefile used by the rather old BBDB v2 compiles the file
> with BBDB autoloads.  Does such a step offer any advantage with a
> recent version of GNU Emacs?

It all depends on what gets put in there.  But if you only get calls to
`autoload' and a few calls to `add-to-list', byte-compilation should not
make any difference to the speed of the code.

Some people have reported that byte-compiling their .emacs makes
a measurable difference to their Emacs's startup time, tho, so there
might some advantage, but I must say I don't know where it comes from
(it must be linked to the way the file is loaded rather than to the
actual evaluation; maybe some decoding overhead or something like that).


        Stefan

Re: Is compiling autoloads useful?

[Lluís]

Stefan Monnier writes:

> Some people have reported that byte-compiling their .emacs makes
> a measurable difference to their Emacs's startup time, tho, so there
> might some advantage, but I must say I don't know where it comes from
> (it must be linked to the way the file is loaded rather than to the
> actual evaluation; maybe some decoding overhead or something like that).

Well, I'd say that's because people's .emacs tend to be more complex than an
autoload file :)


apa!

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Re: Is compiling autoloads useful?

[Roland Winkler]

On Fri Dec 9 2011 Stefan Monnier wrote:
> > The Makefile used by the rather old BBDB v2 compiles the file
> > with BBDB autoloads.  Does such a step offer any advantage with a
> > recent version of GNU Emacs?
> 
> It all depends on what gets put in there.  But if you only get calls to
> `autoload' and a few calls to `add-to-list', byte-compilation should not
> make any difference to the speed of the code.

Thanks!

The file bbdb-autoloads.el is much like the various *loaddefs.el in
the lisp directory (which are not compiled either). It contains
a bunch of autoloads only, except for the lines

(provide 'bbdb-autoloads)
(if (and load-file-name (file-name-directory load-file-name))
    (add-to-list 'load-path (file-name-directory load-file-name)))

> Some people have reported that byte-compiling their .emacs makes a
> measurable difference to their Emacs's startup time, tho, so there
> might some advantage, but I must say I don't know where it comes
> from

I'll try to see whether I can get any measureable difference. Yet I
assume if compiling it made a noticable difference, then compiling the
much bigger standard lisp/loaddefs.el should speed up startup yet
more.

Roland

Re: Is compiling autoloads useful?

[Andreas Schwab]

"Roland Winkler" <winkler@gnu.org> writes:

> I'll try to see whether I can get any measureable difference. Yet I
> assume if compiling it made a noticable difference, then compiling the
> much bigger standard lisp/loaddefs.el should speed up startup yet
> more.

loaddefs.el is preloaded, so it doesn't matter here.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
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Re: Is compiling autoloads useful?

[Roland Winkler]

On Fri Dec 9 2011 Andreas Schwab wrote:
> loaddefs.el is preloaded, so it doesn't matter here.

Thanks. What about the other uncompiled files

mh-e/mh-loaddefs.el       
net/tramp-loaddefs.el     
calendar/cal-loaddefs.el  
calendar/hol-loaddefs.el  
calendar/diary-loaddefs.el
emacs-lisp/cl-loaddefs.el 
calc/calc-loaddefs.el     
cedet/semantic/loaddefs.el
cedet/ede/loaddefs.el     
cedet/srecode/loaddefs.el 

I assume they are loaded if a particular package such as mh-e is
loaded. So they match exactly the kind of situation I have in mind
with the file bbdb-autoloads.el (which maybe should be renamed
bbdb-loaddefs.el).

Roland