From owner-sc22wg5@open-std.org Wed Dec 10 17:10:54 2008 Return-Path: X-Original-To: sc22wg5-dom7 Delivered-To: sc22wg5-dom7@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id 6EA6BC178E1; Wed, 10 Dec 2008 17:10:54 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from proofpoint3.lanl.gov (proofpoint3.lanl.gov [204.121.3.28]) by www2.open-std.org (Postfix) with ESMTP id 57EF2C178D6 for ; Wed, 10 Dec 2008 17:10:52 +0100 (CET) Received: from mailrelay1.lanl.gov (mailrelay1.lanl.gov [128.165.4.101]) by proofpoint3.lanl.gov (8.13.8/8.13.8) with ESMTP id mBAGAnWN003842; Wed, 10 Dec 2008 09:10:49 -0700 Received: from localhost (localhost.localdomain [127.0.0.1]) by mailrelay1.lanl.gov (Postfix) with ESMTP id 7745434378A; Wed, 10 Dec 2008 09:10:49 -0700 (MST) X-NIE-2-Virus-Scanner: amavisd-new at mailrelay1.lanl.gov Received: from cic-mail.lanl.gov (cic-mail.lanl.gov [128.165.4.115]) by mailrelay1.lanl.gov (Postfix) with ESMTP id 5F8F4343795; Wed, 10 Dec 2008 09:10:49 -0700 (MST) Received: from soren.lanl.gov (soren.lanl.gov [128.165.148.20]) by cic-mail.lanl.gov (Postfix) with ESMTP id 453C3208004; Wed, 10 Dec 2008 09:10:44 -0700 (MST) Cc: sc22wg5@open-std.org Message-Id: <4A7809D4-58F0-45CA-8AEC-9520DD4A2666@lanl.gov> From: Craig Rasmussen To: fortran standards email list for J3 In-Reply-To: <20081209114032.1E486C178D6@www2.open-std.org> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v929.2) Subject: Re: (j3.2006) (SC22WG5.3786) [ukfortran] Ballot on the technical content of the TR Date: Wed, 10 Dec 2008 09:10:43 -0700 References: <20081127193527.EF00DC178D9@www2.open-std.org> <20081208024650.76234C4596C@www2.open-std.org> <20081208154207.B50ABC178E0@www2.open-std.org> <493DDCA3.3050104@sun.com> <20081209044540.E9F0AC178E5@www2.open-std.org> <493E0084.1020206@sun.com> <20081209063036.65499CA343D@www2.open-std.org> <20081209114032.1E486C178D6@www2.open-std.org> X-Mailer: Apple Mail (2.929.2) X-NIE-2-MailScanner-Information: Please see http://network.lanl.gov/email/virus-scan.php X-NIE-2-MailScanner: Found to be clean X-NIE-2-MailScanner-From: crasmussen@lanl.gov X-Spam-Status: No X-Proofpoint-Virus-Version: vendor=fsecure engine=4.65.7400:2.4.4,1.2.40,4.0.164 definitions=2008-12-10_06:2008-12-08,2008-12-10,2008-12-10 signatures=0 Sender: owner-sc22wg5@open-std.org Precedence: bulk On Dec 9, 2008, at 4:40 AM, N.M. Maclaren wrote: > > The vast bulk of N1761 doesn't help even existing MPI, You are correct, the vast bulk of N1761 was designed to target a set of library developers different from MPI. In fact when it was voted to proceed with improved C interoperability at Delft, I don't recall that MPI was mentioned. However, the assumed-shape dummy portion of N1761 would allow "real" (i.e., much better) Fortran interfaces to be developed (as I discuss further below). > let alone help MPI to > provide a real Fortran 2003 interface. There are two thrusts regarding new Fortran MPI interfaces. The official one is simply to provide interfaces that are safe to use, that map as closely as possible to the existing C interfaces and don't require recoding of existing applications. The other thrust is to provide "real Fortran" MPI interfaces. I've had discussions with developers of the boost C++ MPI interfaces about how to do similar things in Fortran. However, I've been told that these interfaces would probably not be standardized, though important never the less. The C++ interfaces haven't been standardized because they deviate too far from the original C interfaces. > It is pretty clear that MPI will > continue to say (more-or-less explicitly, as has been done on its > mailing > list) "Don't use assumed-shape arrays, because they aren't portable > - stick > to explicit-size ones." I.e. don't use Fortran 90 - stick to > Fortran 77! > I don't want to put words in your mouth but it sounds like you are in favor of the vast majority of parallel Fortran programmers using the old unsafe Fortran 77 interfaces. (The Fortran 90 interfaces are awful and should be dropped from the MPI standard as far as I'm concerned.) N1761 provides the mechanisms for both a new 3.0 MPI interface for Fortran that is safe to use and also for "real" Fortran interfaces with vendor independent implementations that take advantage of the full features of Fortran. Frankly, the current Fortran interfaces are embarrassment to the Fortran community. They are unsafe to use as described in 3 to 4 pages of the MPI standard. I strongly believe that we must fix this situation. If you don't like the current proposal, please suggest an alternative that meet the requirements of the MPI community. Regards, Craig