From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-344666-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 16431 invoked by alias); 25 Jan 2011 11:03:37 -0000
Received: (qmail 16384 invoked by uid 22791); 25 Jan 2011 11:03:36 -0000
X-SWARE-Spam-Status: No, hits=-2.8 required=5.0	tests=ALL_TRUSTED,AWL,BAYES_00,TW_CP
X-Spam-Check-By: sourceware.org
Received: from localhost (HELO gcc.gnu.org) (127.0.0.1)    by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 25 Jan 2011 11:03:33 +0000
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/47409] volatile struct member bug
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Changed-Fields:
Message-ID: <bug-47409-4-WgvD475x5e@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-47409-4@http.gcc.gnu.org/bugzilla/>
References: <bug-47409-4@http.gcc.gnu.org/bugzilla/>
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0
Date: Tue, 25 Jan 2011 11:11:00 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
X-SW-Source: 2011-01/txt/msg02605.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47409

--- Comment #6 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-01-25 11:03:10 UTC ---
We should at least make sure to use memcpy for the array part in

struct {
  volatile int i;
  int a[100000];
} a, b;
a = b;

do we really want to blow up code-size (and compile-time) for

struct {
  volatile int a[1000000];
} a, b;
a = b;

?  And what's the difference of the above to

volatile struct {
  int a[1000000];
} a, b;
a = b;

?

What do other compilers do for the above?  Is there a DR?