Re: pdumper.c Wstringop-overflow warnings with CFLAGS="-O3" [Re: Emacs 29.2 released]

[Eli Zaretskii <eliz@gnu.org>]

> From: "N. Jackson" <njackson@posteo.net>
> Date: Fri, 19 Jan 2024 01:40:31 +0000
> 
> 
> At 13:06 +0200 on Thursday 2024-01-18, Eli Zaretskii wrote:
> >
> > Version 29.2 of Emacs, the extensible text editor, should now
> > be available
> 
> Thank you Eli for your stalwart maintenance of Emacs and to everyone
> else who has contributed recently (and, indeed, ever).
> 
> Building Emacs 29.2 with CFLAGS="-O3" I get four Wstringop-overflow
> warnings in pdumper.c (see below).  Can I (as an Emacs user) safely
> ignore these warnings?  Note: I don't get these warnings with
> CFLAGS="-O2".

If someone wants to investigate these warnings, please do.  My sincere
suggestion is not to build Emacs with -O3 regardless: it is not going
to give you a faster Emacs, and might even give you a slower Emacs.
That's because the inner-most loops in Emacs are very large, and the
optimization techniques used by -O3 are likely not to work well, while
at the same time the excessive inlining might make those loops larger
and thus overflow the CPU caches, which slows down code execution.

Thanks.