Mail Archives: pgcc/1999/07/08/05:47:49
At 10:10 PM 7/7/99 +0200, you wrote:
>On Wed, Jul 07, 1999 at 03:23:55PM +0100, Vincent Diepeveen wrote:
>> I'm also looking forward to a motherboard that supports 4 or 8 K7s.
>> Considering its expected selling prize, and the fact that we finally
>> get competition for the Xeon now, this really will be a big step forward!
>
>I believe this will be just as expensive as their intel counterparts. And
>worse, such an OpenPIC board would be a totally new design, with totally
>new implementation errors ;) But my opinion doesn't really count anything
>here ;)
It might take some time here we agree, but there is COMPETITION!
Competition is better than not having competition!
>> For the program crafty (crafty is in some official benchmarks by
>> the way, so it makes sense to test it; the command 'bench'
>> gives you after a few minutes a benchmark in crafty; ftp ftp.cis.uab.edu
>
>However, you need to modify crafty a bit to get deterministic results
>(crafty varies moves).
>
>> for crafty. linux versions of crafty are compiled using pgcc)
>But only with -O, as this gives the best results with long longs (sadly).
Yeah bob told me that. i wonder why. what's -O2 doing above -O?
Note that crafty has big bunches of inline assembler, so perhaps that's the
reason?
>> See specs Merced, note that merced has quite some
>> registers; work to do for the compilerfreaks!
>
>I never get tired of announcing the EPIC page at
>http://www.goof.com/pcg/epic/, which offers quite a bit information on
>that subject.
page not found!
>> When compiling my program for some RISC processors i get the impression
>> registers don't get used very smartly (gcc for the alpha
>
>gcc is especially bad at using registers, yes. Especially bad on x86,
>but still not perfect on other architectures. There is big room for
>improvements.
>
>> So i guess compilers not using the major part of the merced registers
>> will be commercial suicide!
>
>There are quite a bit larger problems with the merced than just using
>registers. You need a totally different model, and heavy data as well as
>control speculation.
I still can't wait for a compiler using all those instructions which
now don't get used.
For example just using Pentium pro instruction already now would give
huge speedup, like 20% (internal intel compiler normally is 20% slower,
but using pentium pro instructions it's suddenly only 2.5% slower
than msvc!)
>--
> -----==- |
> ----==-- _ |
> ---==---(_)__ __ ____ __ Marc Lehmann +--
> --==---/ / _ \/ // /\ \/ / pcg AT goof DOT com |e|
> -=====/_/_//_/\_,_/ /_/\_\ XX11-RIPE --+
> The choice of a GNU generation |
> |
>
>
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