Numerical C Extensions Group (NCEG) Meeting Report
Rex Jaeschke
rex at aussie.UUCP
Sun May 14 09:49:10 AEST 1989
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.
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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 <math.h> 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
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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
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