From owner-sc22wg5@open-std.org Mon Jun 6 03:30:25 2011 Return-Path: X-Original-To: sc22wg5-dom8 Delivered-To: sc22wg5-dom8@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id DB942C178E5; Mon, 6 Jun 2011 03:30:25 +0200 (CET DST) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org X-Greylist: delayed 1812 seconds by postgrey-1.18 at www2.open-std.org; Mon, 06 Jun 2011 03:30:24 CET DST Received: from ns.nag-j.co.jp (218-42-159-107.cust.bit-drive.ne.jp [218.42.159.107]) by www2.open-std.org (Postfix) with ESMTP id E31C3C178E3 for ; Mon, 6 Jun 2011 03:30:24 +0200 (CET DST) Received: from 218-42-159-108.cust.bit-drive.ne.jp ([218.42.159.108] helo=Maru6) by ns.nag-j.co.jp with smtp (Exim 4.50) id 1QTOAb-0005xV-Q7 for sc22wg5@open-std.org; Mon, 06 Jun 2011 09:59:53 +0900 Message-ID: <5A1B5F62AB31420A9CBD0153FEBFAD94@Maru6> From: "Malcolm Cohen" To: "WG5" References: <20110605224006.B3F8AC178E3@www2.open-std.org> In-Reply-To: <20110605224006.B3F8AC178E3@www2.open-std.org> Subject: Re: [ukfortran] (SC22WG5.4469) Question on CONTIGUOUS Date: Mon, 6 Jun 2011 10:00:08 +0900 Organization: =?utf-8?B?5pel5pysTkFH?= MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="utf-8"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 15.4.3502.922 X-MimeOLE: Produced By Microsoft MimeOLE V15.4.3502.922 Sender: owner-sc22wg5@open-std.org Precedence: bulk >Question: Does this program conform to the Fortran 2008 standard? Yes. >Reason: Of three compilers that accept the CONTIGUOUS attribute, one >rejects the above, and two accept it. Then one compiler has a bug. > Given 5.3.7 para 1 I would tend to >conclude that the code is invalid. 5.3.7p1 does appear on the face of it to be incorrect. Note that 5.3.7p1 makes no requirement on the program or processor (it does not use "shall"), and there is no normative text to support its first claim. There are no requirements in the procedure chapter (12) on the actual argument corresponding to a nonpointer CONTIGUOUS dummy (there are requirements on contiguous array pointers). Furthermore, 12.5.2.4p10 describes what happens with pointer association when a pointer is associated with a CONTIGUOUS dummy and the actual is not simply contiguous. That text would be meaningless if we did not allow noncontiguous actual arguments for a contiguous dummy. > From a usability point of view I'd consider it a nice feature if the processor > would > do the necessary copy-in/out if the actual argument is non-contiguous. If the > code > is deemed invalid - why was it decided to not support this? In fact we did decide to support it. After all, it's no more work for the compiler than what we already required for explicit-shape and assumed-size arrays, way back in F90 days. Cheers, -- ................................Malcolm Cohen, Nihon NAG, Tokyo.