Re: Native compilation on as default?

[Colin Baxter]

>>>>> Andrea Corallo <acorallo@gnu.org> writes:

    > Colin Baxter <m43cap@yandex.com> writes:
    >>>>>>> brickviking <brickviking@gmail.com> writes:
    >> 
    >> > On Thu, 26 Oct 2023 at 15:28, Richard Stallman <rms@gnu.org>
    >> wrote > (in part):
    >> 
    >> >> Building Emacs with native compilation is a lot more fragile
    >> than >> without.  Meanwhile, many users don't need it because
    >> Emacs is >> fast enough for us without it.
    >> >> 
    >> >> Theefore, we should not enable native compilation by default.
    >> >> 
    >> 
    >> 
    >> 
    >> > To add to what RMS has stated, I'm on an older machine with not
    >> a > lot of room left on the primary partition. I understand
    >> that's on > me, but I wanted to add my notes about my local
    >> experience.
    >> 
    >> > I compiled Emacs as a test with AOT turned on, and found that
    >> it > started creating *.eln files. Lots of them. I recompile
    >> Emacs on a > fairly regular basis, and after one compile/install
    >> of Emacs, I > noted at least an extra 40Mb after about an hour's
    >> running with > erc, org-mode and ef-themes (amongst others). On
    >> my older 2008-era > machine that's starting to really show its
    >> age, the extra .eln > files were not really worth it for me. I
    >> wish I had better news, > I've been wanting a sped-up emacs for a
    >> little while now. To be > fair, I _thought_ I saw a speed
    >> increase in what amounts to > display code, but I'm not a
    >> programmer, mainly a user.
    >> 
    >> > Is there a facility to purge out-of-date versions of the .eln >
    >> files for a version that is installed later, and is that facility
    >> > easy enough to look for via C-h f? This might make native >
    >> compilation easier to swallow.
    >> 
    >> > Regards, brickviking (Emacs 29.1.90, GTK3, Linux-x86_64)
    >> 
    >> I would like to second this. I too run old machines - 15 years
    >> old , but still giving good service. I have tried native
    >> compilation on one, and noticed only the presence of a large
    >> number of extra files with no change in performance. I'm not a
    >> developer and don't do anything fancy on emacs.
    >> 
    >> Po makes a very good point. I compile from git and only one
    >> machine has the necessary library (or libraries?)
    >> 
    >> Best wishes,
    >> 
    >> Colin Baxter.


    > Hi Colin,

    > again, the proposal (see original message) is to have it on by
    > default *only* when libgccjit is available.  I bet you don't have
    > it installed on those machines as AFAIK the only SW in production
    > that uses it is Emacs.

Well, I do have libjccjit-6-dev on a machine running Debian 9.13. This
is the machine on which I did try native compilation. As I said, I could
see zero change in performance of my emacs (30.0.50). There's also
libjccjit-8 on another machine of mine running Debian 10.13.

I now always compile with "--with-native-compilation=no". Are you saying
that this configure option will not in the future be sufficient and I
will have to make sure there's no libjccjit versions on the system?

Best wishes, Colin.