Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!hellgate.utah.edu!dog.ee.lbl.gov!nosc!crash!pnet01!lkoop From: lkoop@pnet01.cts.com (Lamonte Koop) Newsgroups: comp.sys.amiga.programmer Subject: Re: New life for MOVEM! Message-ID: <7806@crash.cts.com> Date: 4 Mar 91 02:36:36 GMT Sender: root@crash.cts.com Organization: People-Net [pnet01], El Cajon CA Lines: 63 hughesmp@vax1.tcd.ie writes: >In article , dej@qpoint.amiga.ocunix.on.ca (David Jones) writes: >>>In article <1991Feb11.160212.7749@vax1.tcd.ie> smcgerty@vax1.tcd.ie writes: >>>How about this, which takes about 2/3 of the time of the above: >>> >>>[..usage of movem deleted..] >>> >>>Anyone got any other tricks? >> >> Ya. Save yourself some code. Check out CopyMem() in exec.library >> (V33 or greater). Disassemble it. Essentially, it is the above code. > >Hey cmon man, he doesn't want to hear about supplied software. Often you >find stuff written by someone else, particularly the OS, sucks. You want Not in my experience. Just because the OS is "supplied" or written by someone else, it doesn't mean you have to go about re-inventing the wheel because you feel "it sucks"...a feeling which I strongly disagree with. Yes, the OS has it's problems, but it has quite a few excellent points to it as well. >one thing quick. It wants something else slow. So you write it _yourself_. >At least that way you know exactly what's going on, how fast, and everyone >will be able to use it. Not just people with V33 or greater, whatever >that is. He asks (if you read the posting) if anyone else has any tricks. >He wants to know if there are any other ways of squeezing more out of what >is basically a not-very-fast-processor. One byte per 4 cycles stinks, so >what'd it be like without movem? Are there any other ways of doing something >else faster; try and get summat out of the machine, if you don't want to >waste your money on a bigger chip in the series? Don't say find out about >the OS, because it is a heap of it. You want _real_optimisation_ for the >specific problem, for which some general ideas may help. Movem is one. The >OS is not. Matt Dillon's program is very nice, coping with non-word >boundaries and everything, but if you want _everything_ out of the machine, >forget those checks. Align your data, and use the plain movems. Shove the >loop in a cupboard, and in-line the code. On a processor running at the >speed of a low 68000, those cycles count. Save them. Don't give a damn about >memory. Remember, only a heartless fiend can get the true max out of the >machine. Work everything to the bloody stumps, and waste everything else. From you comments, I have just a few of my own: First of all, I have absolutely nothing against optimizing code...in fact I am all for it, and any ideas pertaining to it. However, your attitude seems to be quite hostile towards the OS...which is NOT "full of it". In fact, you seem to be the sort who would write code which crashes just about every machine except a particular model. This may not be the case, but I don't see how you would get decently multitasking-friendly applications when you avoid the OS. Second of all, how to you propose to get anything done...when you insist on reinventing everything? > >T. > >SICK - the Slightly Intelligent Crazy Rosebi - >We came. We saw. We went away again. >#! r LaMonte Koop Internet: lkoop@pnet01.cts.com ARPA: crash!pnet01!lkoop@nosc.mil UUCP: {hplabs!hp-sdd ucsd nosc}!crash!pnet01!lkoop "It's a dog-eat-dog world...and I'm wearing Milk Bone underwear"--Norm