public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "dje at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/51766] [4.7 regression] sync_fetch_and_xxx atomicity
Date: Tue, 10 Jan 2012 20:26:00 -0000	[thread overview]
Message-ID: <bug-51766-4-ntOuOl613y@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-51766-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51766

--- Comment #14 from David Edelsohn <dje at gcc dot gnu.org> 2012-01-10 20:25:57 UTC ---
Jakub,

The POWER implementation of __sync_* was not written intentionally to violate
the documentation.  I don't think those of us who implemented the feature on
POWER realized the documentation was trying to require sequential consistency.

Given this clarification, the POWER maintainers need to figure out what
implementation is appropriate.

The lwsync implementation was more than sufficient for the common use of atomic
ops, like fetch_and_<op>.  That other architectures provide stronger semantics
is a bonus.


  parent reply	other threads:[~2012-01-10 20:26 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-05 15:01 [Bug middle-end/51766] New: " dje at gcc dot gnu.org
2012-01-05 15:02 ` [Bug middle-end/51766] " dje at gcc dot gnu.org
2012-01-09 15:40 ` rguenth at gcc dot gnu.org
2012-01-09 15:45 ` redi at gcc dot gnu.org
2012-01-09 16:51 ` dje at gcc dot gnu.org
2012-01-10  9:43 ` rguenth at gcc dot gnu.org
2012-01-10 14:40 ` dje at gcc dot gnu.org
2012-01-10 14:49 ` rguenth at gcc dot gnu.org
2012-01-10 15:31 ` redi at gcc dot gnu.org
2012-01-10 18:09 ` dje at gcc dot gnu.org
2012-01-10 18:20 ` redi at gcc dot gnu.org
2012-01-10 18:24 ` redi at gcc dot gnu.org
2012-01-10 18:34 ` dje at gcc dot gnu.org
2012-01-10 18:47 ` jakub at gcc dot gnu.org
2012-01-10 19:14 ` amacleod at redhat dot com
2012-01-10 20:26 ` dje at gcc dot gnu.org [this message]
2012-01-12 20:41 ` dje at gcc dot gnu.org

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-51766-4-ntOuOl613y@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).