Re: [PATCH] Re: Bignum performance

[Gerd Möllmann]

On 16.08.23 07:18, Gerd Möllmann wrote:
> > I don't know about SBCL, but as for Emacs, refer to the definition of
> > VALBITS in lisp.h (maybe also the right files among m/*.h and s/*.h, but
> > I have no idea where they've disappeared to.)
>
> The SBCL I have here, a Homebrew installation, uses the scheme where

Oops, I'm actually not running the SBCL from Homebrew, but my own...
Anyway, the tagging is like this:

@c 64-bit lowtag assignment (wider-fixnums)
@c xyz0 -- Fixnum (where z or yz may also be 0 depending on 
n-fixnum-tag-bits)
@c xx01 -- Other-immediate
@c xx11 -- Pointer
@c 0011 --   Instance-pointer
@c 0111 --   List-pointer
@c 1011 --   Function-pointer
@c 1111 --   Other-pointer

https://github.com/sbcl/sbcl/blob/master/doc/internals/objects-in-memory.texinfo