[Aldor-l] [fricas-devel] Re: aldor fricas interoperability... call for testers

[Martin Rubey]

Ralf Hemmecke <ralf at hemmecke.de> writes:

> I must say, I would actually rather like to keep the definitions that way. SBCL
> should rather provide fixnum with >=32 bits to be able to work together with
> Aldor.

This is impossible.  sbcl fixnums are built that way - 29 bits on 32 systems
and probably 61 bits on 64 systems.

> So I think, your patch is a hack. Is there somehow explained what bitsize
> 'fixnum' has?

Yes, it is specified in the Common Lisp Standard: at least 16 bit.

> >> Another thing is, if I grep the fricas sources, I only find |SInt| in
> >>
> >> src/interp/axext_l.lisp
> >> src/interp/sys-pkg.lisp
> >> src/interp/foam_l.lisp
> >> src/interp/interp-proclaims.lisp
> >>
> >> So I believe the modification you suggest above should work at least for 32
> >> bit machines. Simply since Axiom does not know SInt, only foam knows.
> > Oh, this is very good news!  So, it's actually sufficient to check that Aldor
> > does not convert axiom's "SingleInteger"s into "SInt"s, which is unlikely, I
> > guess.
> 
> Uff. I have no idea, what the compiler does. But I think the representation of
> SInt coming from Aldor should be identical with the representation of
> SingleInteger in Axiom. So what is the representation of SingleInteger in
> Axiom? Don't say 'fixnum'... ;-)

Yes, it is.  It's just as with MachineInteger: fast but limited.

Martin