From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-383420-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 3781 invoked by alias); 13 Feb 2012 19:14:29 -0000
Received: (qmail 3771 invoked by uid 22791); 13 Feb 2012 19:14:28 -0000
X-SWARE-Spam-Status: No, hits=-2.9 required=5.0	tests=ALL_TRUSTED,AWL,BAYES_00
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; Mon, 13 Feb 2012 19:14:15 +0000
From: "michael.kostylev at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/52238] New: -mms-bitfields: __attribute__ ((aligned (n))) ignored for struct members
Date: Mon, 13 Feb 2012 19:14:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: michael.kostylev at gmail dot com
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-52238-4@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
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: 2012-02/txt/msg01354.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52238

             Bug #: 52238
           Summary: -mms-bitfields: __attribute__ ((aligned (n))) ignored
                    for struct members
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: michael.kostylev@gmail.com


The following test case

% cat > test.c << __EOF && gcc -mms-bitfields test.c && { ./a.out ; echo $? ; }
struct {
    char a;
    char b __attribute__ ((aligned (16)));
} s;

int main()
{
    return (__PTRDIFF_TYPE__)&s.b & 15;
}
__EOF

returns 1, since s.b is not 16-byte aligned (with -mno-ms-bitfields it returns
0, as expected). The test passes with 4.1.2, but fails with 4.2.1 and above.