Xref: utzoo comp.std.c:1188 gnu.gcc:514 Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!rutgers!cs.utexas.edu!uunet!aussie!rex From: rex@aussie.UUCP (Rex Jaeschke) Newsgroups: comp.std.c,gnu.gcc,sci.math.num-analysis Subject: Numerical C Extensions Group (NCEG) Meeting Report Message-ID: <18.UUL1.3#5077@aussie.UUCP> Date: 13 May 89 23:49:10 GMT Organization: Journal of C Language Translation Lines: 156 The following report is reprinted from Volume 1, Number 1 (June 1989) of The Journal of C Language Translation, Copyright 1989 Rex Jaeschke. Permission is granted for duplication and distribution of this report for the purposes of furthering the work of NCEG. %--------------------------------------------------------------- Numerical C Extensions Group Status Rex Jaeschke NCEG Convener Introduction When I conjured up the idea for an ad hoc group to define numerical extensions to C earlier this year, I had no idea as to what the reaction would be. The evidence is now clear that this endeavor is seen as being very worthwhile. Not only have more than 90 people asked to be added to the contact database, but 30 of them attended the one-and-a-half day meeting at Cray Research on May 10--11. The backgrounds of the attendees was diverse. The supercomputing industry was represented via Cray, Convex, Supercomputer Systems, and Thinking Machines. The IEEE community was well represented by Hough (from Sun), Cody (from Argonne Labs), and Thomas (from Apple.) Other organizations represented included Unisys, Microsoft, Digital Equipment Corporation, H-P, CDC, IBM, Solborne, Farance, Inc., University of Minnesota, Intermetrics, and Information and Graphics Systems. The digital signal processing industry was represented by Analog Devices, and LLNL, Army BRL, and Polaroid Corporation represented the user community. Dennis Ritchie from AT&T also participated. There was no real sentiment that we deliberately go against the direction established by ANSI C. In fact, quite the contrary. However, it was recognized that some of ANSI C's constraints may impede our activities resulting in possible conflicts. The whole issue of errno and formatted I/O of NaNs and infinity are examples. The Issues The main purpose of the meeting was to identify and prioritize the principal technical issues. The group then voted on each topic indicating high or medium (or no) priority. The high priority votes were weighted twice as much as the medium, and the following list of priorities resulted. ------------------------------------------ Main Numerical Issues ------------------------------------------ Topic Priority ------------------------------------------ aliasing 29 vectorization 27 complex 27 variably dim arrays 25 IEEE issues 24 exceptions/errno 24 float/long double library 23 parallelization 22 ANSI 21 array syntax 19 extra math functions 17 aggregate initializers 15 inter-language issues 15 wide accumulators 10 math function precision 9 non-zero-based arrays 8 numerical representation 6 new data types 4 new operators 4 function overloading 4 ------------------------------------------ Another topic, ``Arrays as first class objects'' had a high priority (21) but after considerable debate was dropped from the list since it was agreed its addition would likely cause great confusion to existing C programmers. Formation of Subgroups The bulk of the agenda time was then given to the top ten topics, each getting 20--30 minutes. For each of these topics, attendees volunteered to be the primary and alternate coordinator. (The minutes of the first meeting identify these people. In the interim, contact me for details.) The intent is that the real technical work will go on between meetings and be coordinated by the leaders of each subgroup. Then, at the following meeting, each subgroup will present the results of its work and make formal proposals as appropriate. This way, the committee can focus on the final, distilled issues rather than everyone getting involved at all levels. It will also significantly reduce the amount of paper in the mailings. If you wish to participate in any of these subgroups it is your responsibility to contact the leaders and identify yourself, your concerns and how you can help. If your area of interest is not listed here, start your own subgroup and let me know. Mailings and Submissions Most of people interested in NCEG appear to have an e-mail address so that should make the subgroups' job much easier in coordinating various viewpoints and proposals. However, all formal distributions will be by paper mail. Since meetings are to be once every six months there will be two mailings between meetings. The first will occur within 4--6 weeks after a meeting and will contain minutes, new papers and other appropriate correspondence. The second will occur about 4--6 weeks prior to the following meeting. The cut-off date for formal submissions for the September meeting is August 11. Forward all correspondence to me (either by mail or via uunet!aussie!rex) and I will assign it a document number. (Note that I do not have a troff formatter.) However, do that only if your paper is concerned with issues other than those being handled by the subgroups. For subgroup issues, forward papers to the subgroup coordinators so they can include it in their submissions to me. The intent is to avoid excessive duplication of points and to allow the short meeting time to be used more effectively. The more formal documents we have the slower it will go. Tom MacDonald at Cray Research has agreed to do the mailings, at least for the interim. Frank Farance of Farance, Inc., has volunteered to be the redactor of the group's working document. Thanks to Tom and Frank. (Thanks also to Randy Meyers from DEC, who acted as meeting secretary and to Cray for being meeting host.) Formal Affiliation There was general consensus that we become affiliated with a recognized standards organization. The final proposal was that we become a working group within X3J11. If we follow that route, it will result in our publishing a Technical Report, a non-binding report on our findings and recommendations. With suitable planning, we might be able to have that elevated to a Technical Bulletin and get it distributed with the ANSI Standard. Getting our extensions adopted as a standard is also possible, in the long term. At this stage, I plan to ask for agenda time at the next X3J11 meeting to discuss admitting us as a work group. In the interest of economy, the next two meetings are scheduled in the same location and week as those of ANSI C's X3J11. These NCEG meeting dates are September 19--20 (Salt Lake City, Utah), and March 7--8, 1990 (New York City.) %--------------------------------------------------------------- Rex ---------------------------------------------------------------------------- Rex Jaeschke | C Users Journal | Journal of C Language Translation (703) 860-0091 | DEC PROFESSIONAL |1810 Michael Faraday Drive, Suite 101 uunet!aussie!rex | Programmers Journal | Reston, Virginia 22090, USA ----------------------------------------------------------------------------