From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id B4AFC385800A; Mon, 14 Nov 2022 17:16:33 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B4AFC385800A
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1668446193;
	bh=fuy/RW7lY9JV+jDHiE+7BBo0rMj/fW/l574PhXaqxF8=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=tPjhYetEG0X88qEqr8JVfc659qfzC7LhbIk6XEVZD/OzO6V9Fuq2rDL97aPisXh/R
	 R921ihi6ayszrAqoVv/Gx5UbAyRgqiUQlsdesgBE+8WXuJ2P20KbuAokjReAlhhVav
	 RA4subcyJWx7OTPZTc3+T0dcrH66SAFYcKms3hIc=
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/107676] Nonsensical docs for -mrelax-cmpxchg-loop
Date: Mon, 14 Nov 2022 17:16:32 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 12.2.1
X-Bugzilla-Keywords: documentation
X-Bugzilla-Severity: normal
X-Bugzilla-Who: pinskia at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cf_reconfirmed_on bug_status everconfirmed
Message-ID: <bug-107676-4-xvMDg5WJff@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-107676-4@http.gcc.gnu.org/bugzilla/>
References: <bug-107676-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107676

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-11-14
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Maybe this is better:
For loops that are emitted by __atomic_compare_and_exchange (and other
__atomic* builtins which emit a compare and exechange loop, e.g. ....), emi=
t an
atomic load before the loop and if the value was not the expected value, em=
it a
pause instruction. This might reduce execussive cache bouncing of the memor=
y.

Note replace .... with other builtin which also emits a compare and exchange
loop.=