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: 103376,7af3eb61e15f9a0b X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-11-19 07:03:29 PST Path: archiver1.google.com!news1.google.com!sn-xit-02!supernews.com!newsfeed.direct.ca!look.ca!newshub2.rdc1.sfba.home.com!news.home.com!news1.sttln1.wa.home.com.POSTED!not-for-mail From: "DuckE" Newsgroups: comp.lang.ada References: <9t5ihf$dp$1@news.tpi.pl> <5ee5b646.0111171819.d56766d@posting.google.com> <0232EB9B71AA469C.63E4D85432274436.A56779B689231DC6@lp.airnews.net> Subject: Re: pointer movement? X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Message-ID: <4b9K7.46553$XJ4.27342560@news1.sttln1.wa.home.com> Date: Mon, 19 Nov 2001 15:03:28 GMT NNTP-Posting-Host: 24.248.45.203 X-Complaints-To: abuse@home.net X-Trace: news1.sttln1.wa.home.com 1006182208 24.248.45.203 (Mon, 19 Nov 2001 07:03:28 PST) NNTP-Posting-Date: Mon, 19 Nov 2001 07:03:28 PST Organization: Excite@Home - The Leader in Broadband http://home.com/faster Xref: archiver1.google.com comp.lang.ada:16684 Date: 2001-11-19T15:03:28+00:00 List-Id: "John R. Strohm" wrote in message news:0232EB9B71AA469C.63E4D85432274436.A56779B689231DC6@lp.airnews.net... > I *KNOW* this is a stupid question, but (a) did you look at the generated > object code (b) keeping in mind the organization of the memory and the > caching and the response times? No I did not look at the generated object code. I found certain techniques to improve speed by experimenting with the source code. The MVME162 has an available timer on board that permits me to time execution to the nearest nanosecond. I was able to make minor changes to the source code and observe changes to execution speed very easily. > A few years ago, I was doing image processing with a TI 320C80. The way one > walked through the image (row-wise vs. column-wise) made a MAJOR difference > in the raw processing speed, because the RAM arrays could access successive > locations in a "row" a LOT faster than they could access successive > locations in a "column". Some of the processing I was doing naturally > worked on a row at a time; some naturally worked on a column at a time. We > compromised for consistent transfer times by processing small rectangular > patches at a time. I was working with single dimension arrays. > 320C80 image processing code is some of the hardest I have ever done. You > sweat blood for months over a loop with maybe twenty or thirty source > instructions in it, because that loop HAS to touch every pixel in the frame, > and the system HAS to run at video speed. I thank my lucky stars I got my > start on a CDC 6600 all those years ago; the mindset from 6600 programming > came in handy. It's a pity that on occasion we still have to program at this level. SteveD