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From: "Dr. Adrian Wrigley" <amtw@linuxchip.demon.co.uk.uk.uk>
Subject: Re: Ada vs Fortran for scientific applications
Date: Tue, 23 May 2006 23:21:20 GMT
Date: 2006-05-23T23:21:20+00:00	[thread overview]
Message-ID: <pan.2006.05.23.23.20.10.869090@linuxchip.demon.co.uk.uk.uk> (raw)
In-Reply-To: ikMcg.7532$ix2.639@trnddc03

On Tue, 23 May 2006 22:49:50 +0000, Dan Nagle wrote:
> 
> Dr. Adrian Wrigley wrote:
...
>>  I did briefly work
>> on more general ideas for language/hardware co-design using
>> co-arrays and similar.  Initial results were encouraging, but
>> to make use of the technology, you really need a custom parallel
>> processor built.  And rewriting your software :(
> 
> But today, interprocessor communications are approaching
> the performance of memory buses.  I believe co-arrays
> will deliver performance at or better than MPI on many architectures,
> and in many clusters.
> 
> Any application re-write is minimal compared to inserting MPI calls.

Thank you for your input on this topic.  I had looked at things
like UPC when I was looking into the topic.  There still seems
to be quite a spread of different ideas, but only modest "progress".

Something like the new 'Cell' processor would be a good target
for a co-array language.  But instead, the Cell programming tools
have a disappointing, ad-hoc collection of programming (band) aids
to help coders use the parallelism.  It's expected to be "guru" level
coding to get decent efficiency code at the metal.

As regards interprocessor communications vs. memory buses, it depends
at what levels you make the comparisons.  On chip memory arrays
may be 1000's of bits wide at GHz speeds.  Communications between
processor chips are a small fraction of that.

The challenge for co-array and SIMD computing is to work out
simple hardware that can utilize inter- and intra-chip
communications and memories efficiently.  This needs to have
a sensible programming model (eg assembly language, instruction
set architecture).  Only then is it worth considering what language
features (if any) are necessary to compile for it.
Sadly, what passed for SIMD computing in the '70s and '80s
was way too restrictive and often inefficient for its capabilities
to be worth providing for in general-purpose languages.
Progress is glacial :(

I wish the Fortran committee the best of luck with their co-arrays!
--
Adrian




  reply	other threads:[~2006-05-23 23:21 UTC|newest]

Thread overview: 314+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-05-22  4:54 Ada vs Fortran for scientific applications Nasser Abbasi
2006-05-22  6:45 ` Brooks Moses
2006-05-22  7:41   ` Jan Vorbrüggen
2006-05-22 18:49     ` Brooks Moses
2006-05-23  5:51       ` Tim Prince
2006-05-23  8:56       ` Jan Vorbrüggen
2006-05-23 13:28         ` Greg Lindahl
2006-05-24  8:10           ` Jan Vorbrüggen
2006-05-24 15:19             ` Richard E Maine
2006-05-29 12:55               ` Jan Vorbrüggen
2006-05-24 15:24             ` Dick Hendrickson
2006-05-24 19:03               ` glen herrmannsfeldt
2006-05-29 12:56                 ` Jan Vorbrüggen
2006-05-29 20:07                   ` glen herrmannsfeldt
2006-05-30  4:55                   ` robert.corbett
2006-05-30  7:05                     ` Jan Vorbrüggen
2006-05-22 11:48   ` Michael Metcalf
2006-05-22 12:01     ` Dr. Adrian Wrigley
2006-05-23  8:34   ` Jon Harrop
2006-05-22  7:34 ` Dmitry A. Kazakov
2006-05-23  8:32   ` Jon Harrop
2006-05-22  7:36 ` Greg Lindahl
2006-05-22 21:25   ` Ken Plotkin
2006-05-22 21:40     ` blmblm
2006-05-23  2:12       ` Ken Plotkin
2006-05-23 15:32     ` Pascal Obry
2006-05-23 17:33       ` Marc A. Criley
2006-05-22 10:34 ` Tim Prince
2006-05-22 12:52 ` George N. White III
2006-05-22 13:02 ` Jean-Pierre Rosen
2006-05-22 15:23   ` Dan Nagle
2006-05-22 16:20     ` Nasser Abbasi
2006-05-22 16:38       ` Jan Vorbrüggen
2006-05-22 16:41       ` Gordon Sande
2006-05-22 16:48       ` Dan Nagle
2006-05-23  2:12         ` news.hinet.net
2006-05-22 17:22       ` Paul Van Delst
2006-05-23  7:04         ` Gareth Owen
2006-05-23  7:02           ` Martin Krischik
2006-05-23 14:23           ` Rich Townsend
2006-05-23 17:24             ` Brooks Moses
2006-05-23 18:40               ` Rich Townsend
2006-05-23 21:17                 ` Martin Dowie
2006-05-24  2:21                   ` Nasser Abbasi
2006-05-26 15:18                     ` Martin Dowie
2006-05-25 19:43                 ` Janne Blomqvist
2006-05-24  5:26       ` robin
2006-05-24  6:06         ` GF Thomas
2006-05-22 16:38     ` Richard E Maine
2006-05-23  8:25     ` Jean-Pierre Rosen
2006-05-23 11:40       ` Dan Nagle
2006-05-23 13:14         ` Dr. Adrian Wrigley
2006-05-23 17:07           ` Dan Nagle
2006-05-23 22:20             ` Dr. Adrian Wrigley
2006-05-23 22:49               ` Dan Nagle
2006-05-23 23:21                 ` Dr. Adrian Wrigley [this message]
2006-05-24  0:49                   ` Dan Nagle
2006-05-24  5:07                     ` GF Thomas
2006-05-24 12:56               ` J.F. Cornwall
2006-05-24 13:39                 ` Dr. Adrian Wrigley
2006-05-24 16:49                   ` J.F. Cornwall
2006-05-24 18:08                     ` Dr. Adrian Wrigley
2006-05-24  5:26         ` robin
2006-05-27  5:18         ` Aldebaran
2006-05-23 17:09       ` Dick Hendrickson
2006-05-23 17:53         ` Georg Bauhaus
2006-05-23 18:21         ` Dmitry A. Kazakov
2006-05-23 18:34           ` Brooks Moses
2006-05-24  7:15             ` Dmitry A. Kazakov
2006-05-23 20:33           ` Dick Hendrickson
2006-05-24  7:52         ` Jean-Pierre Rosen
2006-05-24 14:50         ` robin
2006-05-24 15:19           ` Dick Hendrickson
2006-05-24 15:43             ` Dr. Adrian Wrigley
2006-05-24 17:12               ` Dick Hendrickson
2006-05-24 17:32                 ` Richard E Maine
2006-05-24 17:54                 ` Dr. Adrian Wrigley
2006-05-24 18:10                   ` Richard E Maine
2006-05-24 18:39                     ` Nasser Abbasi
2006-05-24 19:36                       ` Gautier
2006-05-24 19:37                       ` Gautier
2006-05-24 19:56                         ` Richard E Maine
2006-05-30 19:39                           ` Craig Powers
2006-05-26  2:58                         ` robin
2006-05-24 18:34                   ` Gordon Sande
2006-05-24 18:40                     ` Ed Falis
2006-05-25 22:31                       ` Brooks Moses
2006-05-24 18:43                     ` Ed Falis
2006-05-24 18:59                       ` J.F. Cornwall
2006-05-24 19:10                       ` Gordon Sande
2006-05-25  3:40                       ` robin
2006-05-25 15:19                         ` Martin Krischik
2006-05-27 14:29                           ` robin
2006-05-27 13:22                             ` Georg Bauhaus
2006-05-29 11:46                             ` Jan Vorbrüggen
2006-05-29 17:37                             ` Martin Krischik
2006-05-24 21:04                   ` Dick Hendrickson
2006-05-31  4:26                     ` robert.corbett
2006-05-25  3:40                   ` robin
2006-05-24 16:03             ` Richard E Maine
2006-05-24 19:08               ` glen herrmannsfeldt
2006-05-25  3:40             ` robin
2006-05-25  5:04               ` Nasser Abbasi
2006-05-25  6:04                 ` Richard Maine
2006-05-25 10:42                   ` Shmuel (Seymour J.) Metz
2006-05-25 15:09                     ` Richard E Maine
2006-05-25 19:39                       ` Shmuel (Seymour J.) Metz
2006-05-25 12:09                   ` Dr. Adrian Wrigley
2006-05-25 12:42                     ` Dan Nagle
2006-05-25 12:45                     ` Gordon Sande
2006-05-25 16:23                       ` Checking for Undefined [was Re: Ada vs Fortran for scientific applications] Bob Lidral
2006-05-25 17:48                         ` Nasser Abbasi
2006-05-25 17:57                         ` Gordon Sande
2006-05-25 20:20                           ` Bob Lidral
2006-05-27 14:29                             ` Checking for Undefined robin
2006-05-25 20:35                           ` Checking for Undefined [was Re: Ada vs Fortran for scientific applications] glen herrmannsfeldt
2006-05-25 22:02                           ` Checking for Undefined Simon Wright
2006-05-27 14:29                           ` robin
2006-05-27 15:10                             ` Gordon Sande
2006-05-26  2:58                       ` Ada vs Fortran for scientific applications robin
2006-07-09 20:52                       ` adaworks
2006-07-09 21:33                         ` Brooks Moses
2006-07-10  3:08                           ` jimmaureenrogers
2006-07-10 11:23                           ` Björn Persson
2006-07-10 17:08                             ` Brooks Moses
2006-07-09 21:36                         ` James Giles
2006-07-09 22:29                           ` Martin Dowie
2006-07-09 23:07                             ` James Giles
2006-07-09 23:44                               ` glen herrmannsfeldt
2006-07-11  1:29                               ` robin
2006-07-09 23:19                           ` glen herrmannsfeldt
2006-07-11  1:29                             ` robin
2006-07-11  5:56                               ` glen herrmannsfeldt
2006-07-12  0:37                                 ` robin
2006-07-12  1:15                                   ` glen herrmannsfeldt
2006-07-14  2:47                                     ` Randy Brukardt
2006-07-14  2:56                                       ` glen herrmannsfeldt
2006-07-18  1:48                                     ` robin
2006-07-18 18:35                                       ` glen herrmannsfeldt
2006-07-19 14:35                                         ` BINARY INTEGER robin
2006-07-10  7:38                           ` Ada vs Fortran for scientific applications Dmitry A. Kazakov
2006-07-10 16:41                             ` adaworks
2006-07-10 18:12                               ` John W. Kennedy
2006-07-11  1:29                                 ` robin
2006-07-11  2:49                                   ` John W. Kennedy
2006-07-12  0:37                                     ` robin
2006-07-11  1:29                             ` robin
2006-07-11  6:46                               ` adaworks
2006-07-11  7:30                                 ` James Giles
2006-07-11 20:46                                   ` Simon Wright
2006-07-11 11:44                                 ` Jeffrey Creem
2006-07-11 14:51                                   ` adaworks
2006-07-12  1:29                                     ` Jeffrey Creem
2006-07-11 13:53                                 ` Tom Linden
2006-07-11 15:02                                   ` adaworks
2006-07-11 15:35                                     ` Tom Linden
2006-07-11 16:54                                       ` Alex R. Mosteo
2006-07-11 17:43                                       ` adaworks
2006-07-11 18:15                                         ` Ed Falis
2006-07-11 14:46                                 ` John W. Kennedy
2006-07-11 14:45                                   ` Tom Linden
2006-07-11 17:06                                     ` John W. Kennedy
2006-07-11 15:16                                   ` glen herrmannsfeldt
2006-07-11 15:55                                     ` Richard E Maine
2006-07-11 16:21                                       ` Ed Falis
2006-07-11 16:28                                         ` Richard E Maine
2006-07-12  3:33                                       ` James Dennett
2006-07-11 17:08                                   ` Jean-Pierre Rosen
2006-07-11 22:44                                     ` glen herrmannsfeldt
2006-07-12  9:50                                       ` Jean-Pierre Rosen
2006-07-14  7:00                                         ` glen herrmannsfeldt
2006-07-12  3:35                                     ` James Dennett
2006-07-12  0:37                                   ` robin
2006-07-10  9:57                           ` Georg Bauhaus
2006-07-11 15:14                         ` robin
2006-07-11 17:21                           ` adaworks
2006-07-11 19:50                             ` John W. Kennedy
2006-11-20  9:39                         ` robin
2006-11-21  9:02                           ` Finalization Philippe Tarroux
2006-11-21  9:22                             ` Finalization Dmitry A. Kazakov
2006-11-21 10:32                               ` Finalization Philippe Tarroux
2006-11-21 11:09                                 ` Finalization Dmitry A. Kazakov
2006-11-21 17:29                                   ` Finalization Adam Beneschan
2006-11-21 18:39                                     ` Finalization Dmitry A. Kazakov
2006-11-21 17:22                                 ` Finalization Adam Beneschan
2006-11-21 11:26                             ` Finalization Georg Bauhaus
2006-05-25 16:25                     ` Bounds Check Overhead [was: Re: Ada vs Fortran for scientific applications] Bob Lidral
2006-05-25 22:08                       ` Bounds Check Overhead Simon Wright
2006-05-25 22:27                         ` Brooks Moses
2006-05-25 22:43                           ` Richard E Maine
2006-05-26 10:16                           ` Ludovic Brenta
2006-05-26 10:59                             ` Dan Nagle
2006-05-26 14:44                               ` Dick Hendrickson
2006-05-26 14:52                                 ` Rich Townsend
2006-05-26 16:44                                   ` Ludovic Brenta
2006-05-26 17:49                                     ` Gordon Sande
2006-05-27  9:06                                       ` Dmitry A. Kazakov
2006-05-27 14:44                                         ` Richard Maine
2006-05-29 12:02                                         ` Jan Vorbrüggen
2006-05-26 20:31                                     ` glen herrmannsfeldt
2006-05-27 14:29                                     ` robin
2006-05-26 14:59                                 ` gary.l.scott
2006-05-26 15:10                                   ` Dick Hendrickson
2006-05-26 18:41                                     ` gary.l.scott
2006-05-26 18:56                                       ` Dan Nagle
2006-05-26 19:16                                         ` Richard Maine
2006-05-27 14:29                               ` robin
2006-05-26 16:18                             ` Richard Maine
2006-05-26 17:30                               ` Nasser Abbasi
2006-05-26 18:24                                 ` Richard Maine
2006-05-26 19:23                                   ` Paul Van Delst
2006-05-26 19:25                                   ` Nasser Abbasi
2006-05-26 19:46                                     ` Richard Maine
2006-05-30 19:13                                       ` Robert A Duff
2006-06-04 23:48                                         ` Richard Maine
2006-05-26 18:26                                 ` Rich Townsend
2006-05-26 19:58                                   ` Simon Wright
2006-05-26 20:06                                     ` Rich Townsend
2006-05-26 20:16                                       ` Richard Edgar
2006-05-26 20:28                                       ` Richard Maine
2006-05-30 19:20                                         ` Robert A Duff
2006-06-05 13:50                                           ` Richard Edgar
2006-05-26 20:27                               ` glen herrmannsfeldt
2006-05-26 20:41                                 ` Richard Maine
2006-05-27 14:29                         ` robin
2006-05-27 14:56                           ` Ludovic Brenta
2006-05-27 15:53                             ` jimmaureenrogers
2006-05-27 15:59                             ` Dmitry A. Kazakov
2006-05-27 17:52                               ` Tom LINDEN
2006-05-28  6:28                                 ` Dave Weatherall
2006-05-26  2:58                     ` Ada vs Fortran for scientific applications robin
2006-05-29 12:21                     ` Jan Vorbrüggen
2006-05-29 13:47                       ` Dr. Adrian Wrigley
2006-05-29 14:17                         ` Jan Vorbrüggen
2006-05-29 14:52                           ` Dmitry A. Kazakov
2006-05-29 15:08                             ` Jan Vorbrüggen
2006-05-29 17:03                               ` Dmitry A. Kazakov
2006-05-30  7:11                                 ` Jan Vorbrüggen
2006-05-30  8:29                                   ` Dmitry A. Kazakov
2006-05-31 14:58                                     ` robin
2006-05-31 14:58                                 ` robin
2006-05-31 15:42                                   ` Dmitry A. Kazakov
2006-05-31 15:54                                     ` Gordon Sande
2006-05-31 14:58                             ` robin
2006-05-31 18:07                               ` Marc A. Criley
2006-05-29 15:47                           ` Dr. Adrian Wrigley
     [not found]                   ` <pan.2006.05.25.12.11.52.919554@linuxchip.demon.co.uk.u <2006052514574816807-gsande@worldnetattnet>
2006-05-25 18:30                     ` Checking for Undefined [was Re: Ada vs Fortran for scientific applications] Thomas Koenig
2006-05-25 18:34                       ` Gordon Sande
2006-05-26  2:58                   ` Ada vs Fortran for scientific applications robin
     [not found]                   ` <pan.2006.05.25.12.11.52.919554@linuxchip.demon.co.uk.u <m2r72h69vz.fsf@grendel.local>
2006-05-26  7:54                     ` Checking for Undefined Dirk Craeynest
2006-05-26 15:04                       ` Dick Hendrickson
2006-05-27 14:29                         ` robin
2006-05-27 15:08                           ` Gordon Sande
2006-05-28  0:56                             ` robin
2006-05-28  1:04                               ` glen herrmannsfeldt
2006-05-28 13:46                               ` Gordon Sande
     [not found]                   ` <pan.2006.05.25.12.11.52.919554@linuxchip.demon.co.uk.u <e574mu$rrj$1@scrotar.nss.udel.edu>
2006-05-26 18:53                     ` Bounds Check Overhead Thomas Koenig
2006-05-26 19:07                       ` Richard Maine
     [not found]                   ` <pan.2006.05.25.12.11.52.919554@linuxchip <20060712.7A4E6E0.D028@mojaveg.lsan.sisna.com>
     [not found]                     ` <20060712.7A4E6E0.D028@mojaveg.lsan.sisna.com>
2006-07-14  6:08                       ` Ada vs Fortran for scientific applications Bob Lidral
2006-07-14  6:17                         ` Richard Maine
2006-07-17 12:44                           ` ONES COMPLEMENT (was: Ada vs Fortran for scientific applications) robin
     [not found]                   ` <20060712.7A4E6E0.D028@mojaveg.lsan.sisna <20060714.7A4E988.A30D@mojaveg.lsan.sisna.com>
     [not found]                     ` <20060714.7A4E988.A30D@mojaveg.lsan.sisna.com>
2006-07-16  9:07                       ` Ada vs Fortran for scientific applications glen herrmannsfeldt
2006-07-18  1:48                         ` ONES COMPLEMENT (was: Ada vs Fortran for scientific applications) robin
2006-07-18 18:41                           ` ONES COMPLEMENT glen herrmannsfeldt
2006-07-19 13:41                             ` robin
2006-07-22  0:09                             ` Richard Steiner
     [not found]                   ` <20060712.7A4E6E0.D028@mojaveg.lsan.sisna <20060717.7A4ADD0.10B1A@mojaveg.lsan.sisna.com>
2006-07-18 13:05                     ` ONES COMPLEMENT (was: Ada vs Fortran for scientific applications) Shmuel (Seymour J.) Metz
2006-07-19 11:18                       ` ONES COMPLEMENT Peter Flass
2006-07-19 17:14                         ` glen herrmannsfeldt
2006-07-19 23:43                           ` robin
2006-07-19 13:41                       ` robin
2006-07-19 17:11                       ` ONES COMPLEMENT (was: Ada vs Fortran for scientific applications) Everett M. Greene
2006-07-19 19:40                         ` Shmuel (Seymour J.) Metz
2006-07-20 16:46                           ` Everett M. Greene
2006-07-20 21:47                             ` Shmuel (Seymour J.) Metz
2006-07-21 17:23                               ` ONES COMPLEMENT glen herrmannsfeldt
2006-07-21 18:04                                 ` John W. Kennedy
2006-07-23  0:26                                   ` robin
2006-07-23  0:26                                 ` robin
2006-07-21 20:05                               ` glen herrmannsfeldt
2006-07-21 21:00                                 ` Dick Hendrickson
2006-07-22  6:19                                   ` glen herrmannsfeldt
2006-07-22 15:12                               ` ONES COMPLEMENT (was: Ada vs Fortran for scientific applications) Everett M. Greene
2006-07-23  0:26                               ` ONES COMPLEMENT robin
     [not found]                     ` <20060717.7A4ADD0.10B1A@mojaveg.lsan.sisna.com>
2006-07-19  6:54                       ` glen herrmannsfeldt
2006-07-19 12:47                         ` Tom Linden
2006-07-19 14:35                         ` robin
2006-05-25 11:02               ` Ada vs Fortran for scientific applications Dan Nagle
2006-05-25 11:23                 ` Gareth Owen
2006-05-26  2:58                   ` robin
2006-05-26  7:13                     ` Gareth Owen
2006-05-26 14:53                     ` Dick Hendrickson
2006-05-26 20:18                       ` glen herrmannsfeldt
2006-05-26 21:50                         ` Björn Persson
2006-05-25 14:33                 ` glen herrmannsfeldt
2006-05-26  2:58                 ` robin
2006-05-26 20:03                 ` JA
2006-05-25 11:32             ` Martin Krischik
2006-05-24  6:46       ` Jan Vorbrüggen
2006-05-24  5:26   ` robin
2006-05-23  8:34 ` gautier_niouzes
2006-05-23 13:33 ` Nasser Abbasi
2006-05-23 14:00   ` Michael Metcalf
2006-05-23 15:04   ` beliavsky
2006-05-23 18:09     ` glen herrmannsfeldt
2006-05-23 22:38     ` Jeffrey Creem
2006-05-23 19:29   ` Gautier
2006-05-23 19:34     ` Rich Townsend
2006-05-23 17:57 ` Aldebaran
2006-05-23 22:14   ` Dr Ivan D. Reid
2006-05-23 23:01 ` John
2006-05-27  5:01 ` Nasser Abbasi
2006-05-27  7:36   ` Pascal Obry
2006-05-27 11:18   ` Björn Persson
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