Re: Emacs-diffs Digest, Vol 94, Issue 89

[David Kastrup <dak@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

> Or maybe you mean that Stefan thought casting was not the best idea.
> In that case, I'd like Stefan's opinion on this one:
>
>> -  int frame_lines = FRAME_LINES (frame);
>> +  EMACS_INT frame_lines = FRAME_LINES (frame);
>
> I think down that lane lies madness, because we have lots of struct
> members that are Lisp integers, and assigning the result of XINT of
> every one of them to an EMACS_INT will significantly and unnecessarily
> increase our stack usage (on 64-bit machines).

"Significantly"?  Reality check.  How deep are you planning to recurse?
Are you still trying to fit a working Emacs into 64kB?

The significant costs are, if at all, in the structs containing the
"struct members" since in contrast to the automatic scalar variables of
a typical function that does rarely if ever recurse, there can be lots
of them at once, and apparently those _are_ already EMACS_INT, so _that_
cost, which is likely quite more significant, has already been paid
without people complaining.

-- 
David Kastrup