Re: [Emacs-diffs] master 470082d: List lengths are always fixnums now

[Paul Eggert]

Stefan Monnier wrote:
> What would such a platform look like?
> I guess a CrayI-style platform where `sizeof (void*) == 1` and hence
> `sizeof (struct Lisp_Cons)` can be 2?
> Are there less hypothetical cases we could mention in the comment?

Now that I think about it, I was more worried about architectures where pointers 
(and therefore EMACS_INT) are wider than ptrdiff_t. Something like the IBM i:

https://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_73/rzarh/iptrtypes.htm

These systems are still in production, although highly proprietary. I don't know 
much about them.

Perhaps I should have written the summary as "List lengths are always ptrdiff_t 
now" as that was more the focus of that patch.

Getting back to your question, these days a word-addressible machine would 
probably be a DSP, something like a TI TMS320C3x. Admittedly an unlikely target 
for Emacs, and to some extent this part of the patch is more a comment on one of 
the (many) problems we'd have if we really wanted to port to a word-addressable 
machine.