From owner-sc22wg5@open-std.org Fri Nov 13 21:05:51 2009 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 7C76EC178E4; Fri, 13 Nov 2009 21:05:51 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from mail1.cray.com (mail1.cray.com [136.162.62.100]) by www2.open-std.org (Postfix) with ESMTP id 8A437C178E2 for ; Fri, 13 Nov 2009 21:05:49 +0100 (CET) Received: from beaver.us.cray.com (beaver.us.cray.com [172.30.74.51]) by mail1.cray.com (8.13.6/8.13.3/gw-5323) with ESMTP id nADK5lQJ004007 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Fri, 13 Nov 2009 14:05:47 -0600 (CST) Received: from cfexcas02.americas.cray.com (cfexcas02-2.us.cray.com [172.30.74.228]) by beaver.us.cray.com (8.13.8/8.13.3/hub-5273) with ESMTP id nADK5kVp005695; Fri, 13 Nov 2009 14:05:46 -0600 Received: from cf-vpn-192-168-239-70.us.cray.com (192.168.239.70) by cfexcas02.americas.cray.com (172.30.74.226) with Microsoft SMTP Server (TLS) id 8.1.393.1; Fri, 13 Nov 2009 14:05:45 -0600 Message-ID: <4AFDBC1D.8040505@cray.com> Date: Fri, 13 Nov 2009 14:05:49 -0600 From: Bill Long Reply-To: Organization: Cray Inc. User-Agent: Thunderbird 2.0.0.23 (Macintosh/20090812) MIME-Version: 1.0 To: fortran standards email list for J3 Cc: WG5 Subject: Re: (j3.2006) (SC22WG5.4126) Problems created by some compiler extended size options References: <31F0E6B7-DFAE-4E3D-BA8F-21EDAA094A97@mac.com> <20091113192536.4F805C178E2@www2.open-std.org> In-Reply-To: <20091113192536.4F805C178E2@www2.open-std.org> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Cray-VirusStatus: clean Sender: owner-sc22wg5@open-std.org Precedence: bulk Craig Rasmussen wrote: > There was a discussion at the MPI forum regarding the use of extended > size compiler options. It appears that there some options on some > compilers that promote integers even if the kind parameter is specified. > > The problem with this is that it breaks the C interoperability > standard. For example, the code, > > integer(C_INT) :: i > call bindc_function(i) > > appears to be broken as the variable i will get promoted. I would hope not, assuming the dummy is declared integer(c_int). Such 'promotion' is really 'convert to the KIND of the dummy'. Since bind(c) procedures must have explicit interfaces, the KIND of the dummy is visible. If a compiler blindly converts integers to a particular KIND even when it is obvious that it would result in a kind mismatch, then that is indeed evil, and grounds for filing a big. Cheers, Bill > > Is this a common compiler option? I've been told that users most > often chose the compiler option that promotes everything, even if an > explicit kind is provided. > > I think this practice is evil! > > -craig > > _______________________________________________ > J3 mailing list > J3@j3-fortran.org > http://j3-fortran.org/mailman/listinfo/j3 -- Bill Long longb@cray.com Fortran Technical Support & voice: 651-605-9024 Bioinformatics Software Development fax: 651-605-9142 Cray Inc./Cray Plaza, Suite 210/380 Jackson St./St. Paul, MN 55101