From owner-sc22wg5+sc22wg5-dom8=www.open-std.org@open-std.org Fri Aug 31 08:03:17 2012 Return-Path: X-Original-To: sc22wg5-dom8 Delivered-To: sc22wg5-dom8@www.open-std.org Received: by www.open-std.org (Postfix, from userid 521) id EB2C135699C; Fri, 31 Aug 2012 08:03:16 +0200 (CEST) Delivered-To: sc22wg5@open-std.org Received: from exprod6og114.obsmtp.com (exprod6og114.obsmtp.com [64.18.1.33]) by www.open-std.org (Postfix) with ESMTP id A54BF35671C for ; Fri, 31 Aug 2012 08:03:12 +0200 (CEST) Received: from CFWEX01.americas.cray.com ([136.162.34.11]) (using TLSv1) by exprod6ob114.postini.com ([64.18.5.12]) with SMTP ID DSNKUEBTn4QVYA7Wrr6cDTvWULjcIbXuDta4@postini.com; Thu, 30 Aug 2012 23:03:15 PDT Received: from cfasa-vpn-192-168-233-75.us.cray.com (192.168.233.75) by CFWEX01.americas.cray.com (172.30.88.25) with Microsoft SMTP Server id 14.2.318.1; Fri, 31 Aug 2012 00:58:21 -0500 Message-ID: <504052C4.9000005@cray.com> Date: Fri, 31 Aug 2012 00:59:32 -0500 From: Bill Long Reply-To: Organization: Cray Inc. User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:14.0) Gecko/20120713 Thunderbird/14.0 MIME-Version: 1.0 To: sc22wg5 Subject: Re: (j3.2006) (SC22WG5.4719) Third WG5 ballot on interpretations References: <20120803111404.DC9303568DA@www.open-std.org> In-Reply-To: <20120803111404.DC9303568DA@www.open-std.org> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-sc22wg5@open-std.org Precedence: bulk The following Fortran 2003 interpretations are being balloted: Yes No Number Title -Y- --- F03/0017 Dummy procedure pointers and PRESENT -Y- --- F03/0018 Multiple identical specific procedures in type-bound generic interfaces -Y- --- F03/0019 Multiple identical specific procedures in generic interface blocks -Y- --- F03/0021 What kind of token is a stop code? -Y- --- F03/0046 Unlimited polymorphic pointers in common blocks --- -N- F03/0053 The BIND attribute for C_PTR and C_FUNPTR -Y- --- F03/0065 Relational equivalence --- -N- F03/0084 IEEE_SET_ROUNDING_MODE in a subroutine -Y- --- F03/0096 Can a read statement change the unit value? -Y- --- F03/0103 Restrictions on dummy arguments not present for polymorphic type or parameterized derived type -Y- --- F03/0116 indistinguishable specifics for a generic interface with use association -Y- --- F03/0118 Are lower bounds of assumed-shape arrays assumed? -Y- --- F03/0120 When are parameterized sequence types the same type? --- -N- F03/0121 Precise FP semantics of the REAL intrinsic -Y- --- F08/0004 Is TARGET argument of ASSOCIATED a pointer or nonpointer dummy? -Y- --- F08/0008 IEEE exceptions for intrinsic functions -Y- --- F08/0031 PURE INTENT(OUT) finalization -Y- --- F08/0032 PURE FUNCTION result finalization -Y- --- F08/0038 Are pointless restrictions on DIM arguments intended? --- --- F08/0040 MOVE_ALLOC for coarrays -Y- --- F08/0042 SOURCE= questions Comments: F03/0053: Regarding answer 3, I think it would be better to disallow PRIVATE components in a type with the BIND attribute. A C routine called outside the module where the type is defined, and accessing a variable of such a type would be able to access and modify the PRIVATE components. F03/0084: I was confused by John's comment that the rounding mode on entry to the subroutine affected the value of Z1 since the computation of Z1 follows a call that resets the rounding mode. I think the real question here is what the standard means by "mathematical". I had always thought in terms of things like algebra. John's answer seems to imply that computational numerics (as specified by IEEE) are part of the concept of "mathematical". In other contexts, I think that John's interpretation could be harmful. On the other hand, the current answer does seem to make the usefulness of the IEEE_SET_ROUNDING_MODE routine more limited that would be expected. Also, does the concept of mathematically equivalent apply to the aggregation of multiple statements, or does it apply to just one expression? A processor that used the "mathematically equivalent" argument to get 0 would need to forward sub the expressions for Z1 and Z2 into the print statement to get X*Y - X*Y. I don't think we intended to allow forward substitution of expressions across one of the IEEE mode setting routines. F03/0121: Similar to F03/0084, this hinges on the meaning of "mathematical". I'm not convinced that a processor is allowed to treat X and REAL(X,wp) as mathematically equivalent. The REAL function (may) perform an operation that is outside the scope of normal algebra. -- 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