From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,38fc011071df5a27 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-06-04 02:17:05 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.tele.dk!news.tele.dk!small.news.tele.dk!uninett.no!dax.net!juliett.dax.net!not-for-mail Newsgroups: comp.lang.ada Subject: Re: Ideas for Ada 200X References: <6a90b886.0305262344.1d558079@posting.google.com> <3ED4F3FD.A0EF7079@alfred-hilscher.de> <6vWcnTWjF83bD0qjXTWcpA@gbronline.com> <3EDCBDF4.1050900@attbi.com> From: Ole-Hjalmar Kristensen Message-ID: <7vy90i42z9.fsf@vlinux.voxelvision.no> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 04 Jun 2003 09:16:26 GMT NNTP-Posting-Host: 193.216.12.150 X-Complaints-To: abuse@tele2.no X-Trace: juliett.dax.net 1054718186 193.216.12.150 (Wed, 04 Jun 2003 11:16:26 MET DST) NNTP-Posting-Date: Wed, 04 Jun 2003 11:16:26 MET DST Organization: Tele2 Norway AS Public Access Xref: archiver1.google.com comp.lang.ada:38578 Date: 2003-06-04T09:16:26+00:00 List-Id: 18k11tm001@sneakemail.com (Russ) writes: > Bill Findlay wrote in message news:... > > On 3/6/03 23:20, in article bebbba07.0306031420.69c20f71@posting.google.com, > > "Russ" <18k11tm001@sneakemail.com> wrote: > > > > > I know that Ada is preferable for safety-critical applications, but > > > based on what you are telling me, it sure seems to be a poor choice > > > for non-safety-critical simulation with heavy number crunching. Thanks > > > for clarifying that. I guess C++ is good for something after all, eh? > > > > Only if getting results *fast* is more important than getting them *right*. > > 8-) > > I prefer to get my results both fast *and* right. :^) Seriously, we > are currently doing some "fast-time" sims that take something like 8 > hours of clock time. Two hours would be a lot more convenient, but 32 > would be a lot less. > > > (And let's not forget that Ada *can* compute the result matrix in-place, > > just not using the notation you prefer. It's a strange performance-oriented > > programmer who gives up a factor of 4 for aesthetic reasons.) > > But Mr. Duff says that "+=" is just "syntactic sugar" for "Add(A,B)," > and Mr. Eachus says "+=" needs a temporary to preserve A in the case > of a Constraint_Error. So, as far as efficiency is concerned, we're > screwed either way, aren't we? Not if you explicitly turn off the constraint checking. If you really want performance for matrix operations, consider rewriting the matrix operations in assembler using SSE or equivalent instructions. A speedup with a factor of 4 is realistic on Intel platforms. Gnat has excellent assembler facilites, btw. -- Ole-Hj. Kristensen ****************************************************************************** * You cannot consistently believe this sentence. ******************************************************************************