flipCode - Tech File - Alexander Herz [an error occurred while processing this directive]
Alexander Herz
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E-Mail: softcore@web.de



   05/15/2000, parties&fpu fun


hi folks...

this is just a short update as I have a soccer match in a couple of minutes... a month ago I visited the mekka&symposium party in falling bostel in germany.. I was curious to meet some ppl with similar interests... I'm living in bavaria..so I had to travel 10h via train to get there and I carried my P133 (shame on me) which suckingly was no minitower with me (heavy thingy such tower isn't it :) but I think it was worth it..

firstly in the train I was afraid that this party was going to take place in a stable..the realy slow and old train stopped at every station we reached and there were cows and sheep all over there..luckily it was a big rather clean hall with tons of computers in it.. there I met nufan for the first time irl..he has a cool nordish accent and is a nice lad as most ppl there are..(by the way...he features a quite nice homepage http://www.skullpture.de and is heavily trying to build up a german coders scene... also he's going to organize a little party...just swing by at his homepage top get more info or mail him..I hope he'll forgive me saying this without having ask him :)..I was not able to stay at the party till the end..my mum had birthday :(

but I saw many realy cool demos(along with even more realy bad ones)..especially the amiga 4k ones were impressive..it's cool what you can do with 4k of ram.. in my apps the banner of the logfile(which is in html) exceedes this size easily :) but I'm far more into writing complete apps rather than small(but cool) demonstrations of efects..but respect to those 4k coders..

I coded a little demo style effect(in fact I was playing around with the optimization of my bezier tesselator which will be used in my engine)..I added a bit of sound made by a friend and had it run on my and my neighbours system...it worked perfectly.. sadly it didn't work on the compo system..so it was not shown..I couldn't fix it as I was already on my way home(another 10h without sleep..try to sleep in an ICE..)

let's have a short brake and jump over to coding(you remember the title..it was party AND fpu fun)

I looked at the asm code the compiler output (msvc one.. don't own the intel :( )... I had just started with fpu stuff..so I was not to expirienced with it..I saw that there were awful many mem accesses...if you optimize code using cpu you should try to keep stuff in regs rather than accessing the mem..as that is far faster..so I thought I could apply the sanme rule to fpu...I rewrote the inner parts of my tesselation routine in asm and managed to decrease mem stuff to a minimum...just took me one night(on the party) it was rather trickey..as fpu is badly documented (had to download a nasm doc..the info on the intel page was shit)..I dnno which ideot invented the register stack for fpu..but it realy sux that your regs move around all the time...

anyways..I ran the code ..just to find out that I' actually slower than the msvc version.. it realy wondered me so I vtuned the shit...that way I found out that doing an fmul with an argument in mem just takes one cycle (if done properly)..where as doing all your calcs in the fpu regs stalls the fpu...(A little warning on the intel dev page had saved me hours of work)

well..let's see it optimistically..we learned something.. I'm looking forward to the time when everybody has ISSE and the compiler does this shit properly(some parts of my asm source were still faster than the compiler's shit)

also I learned that my cpu does not support fcompi..

enough of this.. back to the party. it was cool and disappointing on the same time... cool was the ambiente...some nice ppl ...some knowing ppl..realy cool music..coding all over the night and having fun... disappointing was that there were SO few ppl actually coding... most of em were playing HL or downloading porns and stuff... but I met some ppl at the party making a realy cool engine *wink dag,felix*..

cya next time,
Alex





  • 07/05/2000 - fastculling
  • 05/15/2000 - parties&fpu fun
  • 04/03/2000 - Tech File Update
  • 02/11/2000 - Tech File Update
  • 01/14/2000 - Tech File Update
  • 06/28/1999 - Rendering Cities
  • 06/24/1999 - Bones Animation
  • 06/22/1999 - Introduction

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