[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

From: Paul Eggert
Subject: Re: [Emacs-diffs] master 470082d: List lengths are always fixnums now
Date: Fri, 11 Jan 2019 11:10:30 -0800
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1

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:


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.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]