Author: Dieter Buerssner
Date: 11:13:48 05/17/03
Go up one level in this thread
On May 17, 2003 at 13:36:02, Ulrich Tuerke wrote:
>On May 17, 2003 at 11:50:26, Jouni Uski wrote:
>
>>It's not nice, when NPS counter goes after only one hour to zero with fast PC:-)
Indeed. When I started, I had a 386SX and an Atari ST. I was happy, when I saw
1000 nodes/s. I just did not imagine, how fast it would be, to hit 2^32 nodes.
>>I noticed, that Fritz, Shredder and Crafty (Chessbase) have 64b node counter!
>>But at least Ruffian and Yace don't support? Why? Is there may limit in UCI
>>specification?
No, to my knowledge there is no (practical) limit in the UCI specification for
this.
>It depends on the Compiler. Not all C-compiler implementations support 64 bit
>integer types. Microsoft C for instance does. Furthermore the corresponding
>types - if supported at all - are not standardized. Some compilers call them
>"__int64" and others "long long". If an author has code which is used for
>various platforms with differing compilers, then it's a bit of a mess.
Even more of a problem is printing the nodes for a C-program, IMHO. Typedefing a
counter type would be not too much mess compared to that. But all the printf
format strings must be changed. I have lots of those (most are only in debugging
code, but all would need to be changed). It can of course be done, but it is
quite a bit of work. Standard C has (unsigned) long long now (since the new
C-Standard from 1999). The format specifier is %lld/%llu. MSCV to my knowledge
does not support it yet. You need %I64u, or something like this. So it is not a
matter, of only changing one character in each format-string. One needs some
#defines, too. It would need quite some reformating. For example
instead of
printf("%2d %10lu %s\n", depth, nodes, pv);
printf("%2d %15" COUNTER_TYPE_SPECIFIER " %s\n", depth, nodes, pv);
Or another level of indirection, by some format_counter_type routine (with
possible many parameters, like the counter, a buffer, some alignment flags,
length) for example.
Here, C++ programs seem to have a clear advantage, when they use the I/O methods
of the library.
BTW. I started to change for one counter as an experiment (the normal node
counter), and used unsigned long long and double. The funny result: with both
methods, the program ran reproducably 0.5% faster ...
Double may sound a bit fuzzy for a node counter. But all slighty current
computers have IEEE compatible floating point. This guarantees, that it will
work well until 2^54 (all smaller integers are exactly represantable as a
floating point number. Also addition and subtraction of integers will allways
yield the exact result in this range). Until we hit that number, some time will
be needed.
Regards,
Dieter
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