From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-440661-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 31543 invoked by alias); 17 Jan 2014 06:41:07 -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
Received: (qmail 31505 invoked by uid 48); 17 Jan 2014 06:41:02 -0000
From: "hpa at zytor dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/59854] New: Types with specific endianness
Date: Fri, 17 Jan 2014 06:41:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords:
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: hpa at zytor 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-Flags:
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter
Message-ID: <bug-59854-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2014-01/txt/msg01803.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59854

            Bug ID: 59854
           Summary: Types with specific endianness
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hpa at zytor dot com

For integer (and ideally floating-point) types, it would be very nice to be
able to explicitly specify bigendian or littleendian, with the definition that
when stored in memory, these types are byteswapped if necessary.  This would
allow a much more natural and less error-prone way to build data structures for
interchange than what is currently possible.

Obviously, the "as if" rule applies: if it is not observable that something is
stored in memory (e.g. a stack variable for which an address is never taken)
the compiler is allowed to elide the byte swapping as an optimization.

Ideally, this should be added to the C and C++ standards, but perhaps an
implementation in gcc would help make that actually happen.