Re: [feature/native-comp] breakage on build

[Eli Zaretskii]

> From: Andrea Corallo <akrl@sdf.org>
> Cc: phillip.lord@russet.org.uk, monnier@iro.umontreal.ca, emacs-devel@gnu.org
> Date: Wed, 10 Feb 2021 20:41:07 +0000
> 
> > 4.5 min out of how much?  Isn't building Emacs with native-comp take a
> > long time anyway?
> 
> IIRC the full AOT build on my dev machine (8 core 16 threads) is ~19mins.

That's 20%, not too bad.

> > How about if we make the necessary assembly snippet part of the DEFUN
> > macro?  Then compiling each .c file will produce those trampolines
> > ready to be used, no?  (I admit that I don't really understand the
> > details of those trampolines, so maybe the above makes no sense.)
> 
> Yes, that would be equivalent for a primitve foo to expand also
> something like.
> 
> Lisp_Object
> Ffoo_trampoline (Lisp_Object arg1, Lisp_Object arg2)
> {
>   return CALLN (Ffuncall, Qfoo, arg1, arg2);
> }
> 
> At this point one need also a mechanism set the Ffoo_trampoline address
> in our link table when foo is redefined.
> 
> One downside of this approach is that the binary is statically bloated
> by rarely used code.

How many bytes is the trampoline?  With 1500 primitives, we are
talking perhaps about 20KB bloat?  That's not very significant, IMO.