From: Stefan Monnier <monnier@iro.umontreal.ca>
To: emacs-devel@gnu.org
Subject: Re: emacs-26 9e59de9: Use GCALIGNED properly for GCC
Date: Fri, 10 Nov 2017 13:02:57 -0500 [thread overview]
Message-ID: <jwvr2t6xbbe.fsf-monnier+gmane.emacs.devel@gnu.org> (raw)
In-Reply-To: 8d9c169a-5f58-6958-9fca-4c68fa547ba3@cs.ucla.edu
>>> union gcaligned_foo { struct foo s; int64_t gcaligned; };
>> Are int64_t necessarily aligned on multiples of 8 on 32bit platforms?
> No, unfortunately.
That was my impression as well.
> That does not work either, alas, as C11 says 'alignas (8)' is an error when
> the natural alignment of the object is less than 8. This is one of the
> problems that we have encountered in earlier attempts to fix this bug. 'char
> alignas (8)' avoids this problem.
I don't follow: the natural alignment for `char` is definitely less than
8, so if "'alignas (8)' is an error when the natural alignment of the
object is less than 8", how can "char alignas (8)" avoid the problem?
Stefan
next prev parent reply other threads:[~2017-11-10 18:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20171109031206.7056.28312@vcs0.savannah.gnu.org>
[not found] ` <20171109031208.D2CAF2033E@vcs0.savannah.gnu.org>
2017-11-09 23:31 ` emacs-26 9e59de9: Use GCALIGNED properly for GCC Glenn Morris
2017-11-10 7:10 ` martin rudalics
2017-11-10 8:06 ` Eli Zaretskii
2017-11-10 8:26 ` Paul Eggert
2017-11-10 9:57 ` Eli Zaretskii
2017-11-10 16:23 ` Stefan Monnier
2017-11-10 17:58 ` Paul Eggert
2017-11-10 18:02 ` Stefan Monnier [this message]
2017-11-10 18:11 ` Philipp Stephani
2017-11-10 19:19 ` Paul Eggert
2017-11-10 20:31 ` Stefan Monnier
2017-11-10 20:45 ` Paul Eggert
2017-11-11 7:08 ` Paul Eggert
2017-11-11 7:57 ` Paul Eggert
2017-11-11 8:34 ` martin rudalics
2017-11-11 8:50 ` Paul Eggert
2017-11-11 9:46 ` martin rudalics
2017-11-11 8:33 ` martin rudalics
2017-11-13 18:19 ` Paul Eggert
2017-11-13 18:45 ` martin rudalics
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=jwvr2t6xbbe.fsf-monnier+gmane.emacs.devel@gnu.org \
--to=monnier@iro.umontreal.ca \
--cc=emacs-devel@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).