Re: warnings compiling Emacs 22 on amd64

[Eli Zaretskii]

> Cc: address@hidden,  address@hidden
> From: Stefan Monnier <address@hidden>
> Date: Mon, 11 Dec 2006 23:48:43 -0500
> 
> > Is it really that smart?  Will it also be that smart if we do some
> > arithmetics, like `(EMACS_INT)i + 0L' or `(EMACS_INT)i*1L'?
> 
> Could be, or maybe not.  My guess is that the optimization scheme uses an
> abstract domain where integer values are approximated by bounds (so a char
> is approximated by [-128..127]), so "+1" should be handled just fine (after
> conversion to EMACS_INT this same char is still [-128..127] and since "1"
> is most likely approximated by [1..1], then the sum of the two will be
> approximated by [-127..128]).
> 
> But why should it matter whether it does or not?

Because if we understand that, we could devise a way to defeat the
warning.

> I agree with the intention but I wouldn't want to "fix" the warnings by
> applying the optimization by hand, unless the code after optimization is
> just as clean and maintainable.

I don't see how it can be less maintainable than it is now, what with
the multi-layered macros we sprinkle everywhere.