Author: Robert Hyatt
Date: 15:03:10 06/29/04
Go up one level in this thread
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.
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.
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