Author: Gerd Isenberg
Date: 01:16:27 07/30/04
Go up one level in this thread
On July 30, 2004 at 00:07:12, Walter Faxon wrote:
>On July 29, 2004 at 05:53:08, Gerd Isenberg wrote:
>
>>On July 29, 2004 at 05:04:50, Hristo wrote:
>>
>>>On July 29, 2004 at 04:32:56, Gerd Isenberg wrote:
>>>
>>>>On July 29, 2004 at 03:22:54, Hristo wrote:
>>>>
>>>>>On July 28, 2004 at 18:34:32, Joshua Shriver wrote:
>>>>>
>>>>>>Has anyone here done a test of Apple's G5 vs an AMD Opteron?
>>>>>>
>>>>>>
>>>>>>Right now, I'm at a critical state in my source code.
>>>>>>While I do love Apple, I'm wondering which is better to go with.
>>>>>>Apple G5's or AMD Opteron's (Intel Itanium is out of the equation... to
>>>>>>expensive and not worth it comapred to Opteron)
>>>>>>
>>>>>>I've slaved over burgers, and over the year even tacos... I've saved up enough
>>>>>>money... and can buy one or the other..
>>>>>
>>>>>If you switch to lettuce you might be able to get a Cadillac too. :-)
>>>>>
>>>>>>
>>>>>>Right now I really like and love the Apple G5... and to behonest... would love
>>>>>>to have a G5... (but mostly as a desktop OS for my own enjoyment)...
>>>>>
>>>>>I would do exactly that!
>>>>>The G5 is a more interesting CPU and the Apple systems are generally better than
>>>>>the PCs (AMD, Intel).
>>>>
>>>>
>>>>Even in the past Motorola CPU's had IMHO the "better" designs.
>>>>6502 versus 8080 or 68000 versus the "awful" 8086.
>>>>Unfortunately, for what reasons ever, i allways programmed for Intel/AMD cpus.
>>>>
>>>>Thanks to AMD64 my "sympathy gap" between Intel/AMD and Motorola/IBM becomes
>>>>narrower.
>>>>
>>>>
>>>>>
>>>>>I find it to be very entertaining to play with Altivec.
>>>>
>>>>
>>>>Yes, it looks Altivec SIMD instructions are much more consistent than Intel's
>>>>SIMD instructions:
>>>>
>>>>http://www.simdtech.org/apps/group_public/download.php/26/Altivec%20formatted.1.2.pdf
>>>>
>>>>What kind of algorithms did you try with Altivec?
>>>>Did you tried Kogge-Stone sliding attack getters?
>>>>What about a bit[64]*short[64] or bit[64]*byte[64] dot products?
>>>
>>>I don't know what the "Kogge-Stone" algorithm is. ;-/
>>
>>A parallel prefix fill algorithm, introduced here in CCC by Steffan Westcott, to
>>generate sliding attacks in one direction with two bitboards, the generator and
>>the propagator. The generator is the set of the sliding pieces, (eg. rooks) the
>>propagator is the set of empty squares.
>>
>>For AMD64 i intend to use 128-bit wrappers for "vectors" of two bitboards.
>>One with 128-bit SIMD registers (SSE2 -> xmm registers), the other with pairs of
>>64-bit general purpose registers. In general i use template functions for
>>Kogge-Stone, where the type template determines the register incarnation of the
>>bitboard vector. The vector usually contain bitboards for white and black as
>>well as other disjoint generators:
>>
>>template <class T>
>>void upAttacks(sTarget* pTarget, const sSource* pSource)
>>{
>> T gu(&pSource->rooks);
>> T pu(&pSource->occup);
>> pu = ~pu; // empty squares
>>
>> gu |= pu & (gu<<8);
>> pu &= pu<<8;
>> gu |= pu & (gu<<16);
>> pu &= pu<<16;
>> gu |= pu & (gu<<32);
>>
>> (gu<<8).store(&pTarget->up);
>>}
>>
>>Horizontal or diagonal directions require one leading and one trailing "and" to
>>get rid of the board wraps.
>>
>>Gerd
>
>
>Hi, Gerd!
>
>Have you considered producing a web page to consolidate all your advanced bit
>algorithms (SIMD etc.) for other programmers? The alternative is for us to do a
>lot of searching in the CCC archives -- and still maybe not getting your best
>thoughts.
>
>That is, if you want to encourage competitors to experiment with your tools...!
>:)
>
>-- Walter
Hi Walter,
thanks, probably some day i will do it,
but i still have no own webpage.
The archives are not that bad...
And of course i'm a kind of lazy ;-)
Specially with things, like looking for a new provider...
Cheers,
Gerd
>
> [remainder snipped ]
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.