public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/56726] i386: MALLOC_ABI_ALIGNMENT is too small (usually)
Date: Mon, 25 Mar 2013 20:04:00 -0000 [thread overview]
Message-ID: <bug-56726-4-tOt36CYe3E@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-56726-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56726
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hjl.tools at gmail dot com
--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> 2013-03-25 20:04:44 UTC ---
(In reply to comment #0)
> Observed malloc alignment for the i386 ABI is double POINTER_SIZE.
> BITS_PER_WORD, the current default, is usually too small. (It's right only on
> X32.)
>
> Proposed patch:
>
> --- gcc/config/i386/i386.h (revision 197055)
> +++ gcc/config/i386/i386.h (working copy)
> @@ -815,6 +815,14 @@
> x86_field_alignment (FIELD, COMPUTED)
> #endif
>
> +/* The maximum alignment 'malloc' honors.
> +
> + This value is taken from glibc documentation for memalign(). It may
> + be up to double the very conservative GCC default. This should be safe,
> + since even the GCC 4.8 default of BIGGEST_ALIGNMENT usually worked. */
> +
> +#define MALLOC_ABI_ALIGNMENT (POINTER_SIZE * 2)
> +
This isn't correct for x32, whose pointer size is 4 bytes with malloc
aligned to 16 bytes.
next prev parent reply other threads:[~2013-03-25 20:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-25 19:11 [Bug target/56726] New: " chip at pobox dot com
2013-03-25 20:04 ` hjl.tools at gmail dot com [this message]
2013-03-25 21:35 ` [Bug target/56726] " chip at pobox dot com
2013-03-25 22:07 ` hjl.tools at gmail dot com
2013-03-25 22:36 ` chip at pobox dot com
2013-03-26 14:27 ` rguenth at gcc dot gnu.org
2013-03-29 6:05 ` chip at pobox dot com
2013-09-05 20:05 ` chip at pobox dot com
2014-06-12 17:11 ` chip at pobox dot com
2015-04-02 11:36 ` fweimer at redhat dot com
2015-04-02 11:53 ` jakub at gcc dot gnu.org
2015-04-02 21:48 ` chip at pobox dot com
2015-04-06 16:28 ` fweimer at redhat dot com
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=bug-56726-4-tOt36CYe3E@http.gcc.gnu.org/bugzilla/ \
--to=gcc-bugzilla@gcc.gnu.org \
--cc=gcc-bugs@gcc.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.
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).