Author: Robert Hyatt
Date: 20:37:10 06/30/04
Go up one level in this thread
On June 30, 2004 at 20:40:44, Vincent Diepeveen wrote:
>On June 30, 2004 at 03:19:12, Tony Werten wrote:
>
>>On June 29, 2004 at 18:03:10, Robert Hyatt wrote:
>>
>>>On June 29, 2004 at 16:04:23, Vincent Diepeveen wrote:
>>>
>>>>On June 29, 2004 at 12:52:43, Robert Hyatt wrote:
>>>>
>>>>>On June 29, 2004 at 12:31:00, Vincent Diepeveen wrote:
>>>>>
>>>>>>On June 29, 2004 at 09:00:51, Ingo Bauer wrote:
>>>>>>
>>>>>>>On June 29, 2004 at 08:26:15, Zach Wegner wrote:
>>>>>>>
>>>>>>>>One important point is that crafty uses bitboards, so it will have an additional
>>>>>>>>speedup on a 64 bit processor.
>>>>>>>
>>>>>>>http://www.talkchess.com/forums/1/message.html?372849
>>>>>>>
>>>>>>>According to yesterdays news its ~47%. Assuming that the hardware is equal and
>>>>>>>that double speed gives 60 ELO Crafty wins 30 ELO. We will see soon if this will
>>>>>>>be enough.
>>>>>>>
>>>>>>>Bye Ingo
>>>>>>
>>>>>>The 32 bits version is using 8 registers.
>>>>>>The 64 bits version uses 16 registers.
>>>>>>
>>>>>>And another few tiny differences.
>>>>>>
>>>>>>Crafty loses always 1 register to index which thread it is using, so the
>>>>>>advantage of going from 8 to 16 is a big one.
>>>>>>
>>>>>>Then i do not know whether the 64 bits version uses inline assembly versus the
>>>>>>32 bits version not using it and the compiler versions and type of compilers
>>>>>>used is unclear.
>>>>>
>>>>>
>>>>>If you are going to write about what you don't know, we are going to be here all
>>>>>day.
>>>>>
>>>>>the pointer cost me 3-4% when I added it a few years back. That is not going to
>>>>>be a "big one" when moving to 16 registers.
>>>>>
>>>>>Both versions use inline assembly for FirstOne() and LastOne() and that's it.
>>>>>There is no other assembly in Crafty other than my spinlock code for the SMP
>>>>>stuff...
>>>>>
>>>>>On windows there is no inline asm at all as windows has a built-in intrinsic to
>>>>>get to BSF/BSR...
>>>>
>>>>Do you run in windows at the world champs 2004?
>>>
>>>If I could, yes. the compiled executables Eugene produces are faster than
>>>anything I can do on linux.. And XP runs crafty just as well, and Eugene's numa
>>>memory stuff works just fine with no twiddling as I have to do on linux from
>>>version to version..
>>>
>>>However, here is the huge amount of inline asm I have in Crafty:
>>>
>>>int static __inline__ FirstOne(long word)
>>>{
>>> long dummy, dummy2;
>>>
>>>asm(" bsrq %0, %1" "\n\t"
>>> " jnz 1f" "\n\t"
>>> " movq $-1, %1" "\n\t"
>>> "1: movq $63, %0" "\n\t"
>>> " subq %1, %0" "\n\t"
>>> :"=r&"(dummy), "=r&" (dummy2)
>>> :"0"((long) (word))
>>> :"cc");
>>> return (dummy);
>>>}
>>>
>>>
>>>int static __inline__ LastOne(long word)
>>>{
>>> long dummy, dummy2;
>>>
>>>asm(" bsfq %0, %1" "\n\t"
>>> " jnz 1f" "\n\t"
>>> " movq $-1, %1" "\n\t"
>>> "1: movq $63, %0" "\n\t"
>>> " subq %1, %0" "\n\t"
>>> :"=r&"(dummy), "=r&" (dummy2)
>>> :"0"((long) (word))
>>> :"cc");
>>> return (dummy);
>>>}
>>>
>>>
>>>Ten whole assembler instructions. And had I renumbered my bits in the right
>>>way, this would be a grand total of _two_ assembler instructions rather than 10.
>>
>>I've read that before. What is the right way ?
>>
>>H8 at bit0 and A1 at bit63 ? And why ?
>
>I guess in order to take away all possible fun you can have improving your
>evaluation function :)
Or it just makes it harder for those with limited mental acuity to understand
what is going on. Doubt Tony will have that problem however...
>
>>Tony
>>
>>>
>>>Crafty really does have a "huge amount of inline assembly" doesn't it???
>>>
>>>Please stop saying that.
>>>
>>>
>>>
>>>
>>>>
>>>>This i ask because Eugene's beta compiler won't run under linux i guess...
>>>
>>>
>>>Of course it won't. It is a windows product.
>>>
>>>
>>>
>>>
>>>>
>>>>By the way i thought Eugene was working at the IA64 a while ago, has that team
>>>>been moved to x86-64 nowadays and has IA64 development been stopped now?
>>>
>>>
>>>I can't speak for him. His compiler works on _all_ platforms, obviously. He is
>>>working on all three so far as I know.
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.