Re: MPS experiment successful

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: emacs-devel@gnu.org
> Date: Wed, 17 Apr 2024 20:34:47 +0200
> 
> > You mean --with-wide-int?
> 
> Yes, I think that's it. With 64 bit words, this makes Lisp_Object 128
> bits, right?

Possibly, except that no one uses that on a 64-bit platform, AFAIK.  I
use it for a 32-bit build, where it makes Lisp objects 64-bit.

> If that's the case, MPS won't work because if demands that
> references are of word/pointer size, AFAIU.

Ouch!  That's a real turn-off!

> OTOH, hm, pointers will still be of word size, so maybe one could come
> up with something clever. Don't know what ATM, though, especially when
> you say you are using !USE_LSB_TAG.

The --with-wide-int build doesn't need to use USE_LSB_TAG because
there's more than enough bits at the MSB end.

> > That and the previous item is a huge turn-off for me personally, FWIW,
> > because I use exactly these two features.
> 
> If you want !USE_LSB_TAG, someone (tm) could implement that :-). But
> it's not there now, because I didn't want to get lost in the lisp.h
> macro jungle while still learning MPS. Keep it simple, and so on...

OK, but I cannot do anything with a branch I cannot build on my main
development machine.  So here we are.