Author: Dezhi Zhao
Date: 08:15:24 02/21/03
Go up one level in this thread
On February 21, 2003 at 04:14:49, Uri Blass wrote:
>On February 20, 2003 at 13:51:37, Filip Tvrzsky wrote:
>
>>On February 20, 2003 at 12:49:39, Uri Blass wrote:
>>
>>>
>>>I guess that you mean
>>>#define gen_dat_i_mpromote (gen_dat[i].m & (63 << 16))
>>>
>>>I guess that the laternative that I tried
>>>
>>>#define to(x) (((x)>>8)&255) was also bad
>>>and better was
>>>#define to(x) (((x)&255<<8)
>>>
>>>I guess that in that case I need to change some more code
>>>
>>>For example
>>>
>>>I have today some cases when I have
>>>switch(m.bits)
>>>case 1:
>>>case 17:
>>>...
>>>
>>>in that case I need to say case 1<<24 and in order not to have an ugly code
>>>I need to have more constants for 2^24,2^24*17,...
>>>
>>>I can use
>>>enum
>>>{
>>> bits1=16777216
>>> bits17=
>>>...
>>>}
>>>
>>>Uri
>>
>>#define to(x) (((x)>>8)&255) is definitely worse than #define to(x)
>>(((x)&255<<8) because in the first case the shifting is done in run-time and in
>>the second during compilation. Note also that the result of both macros is
>>different.
>
>Yes
>
>This is an important note.
>
>I did not do the mistake of assuming that they are the same but I see that I
>have problems.
>
>I cannot use my usual macros after that translate
>
>for example
>
>I had if (piece(m.b.to))=PAWN) in my code
>I cannot transalate it to
>if (piece(to(m))==PAWN) because to(m) does not get something between 0 and 63
>after the change and it seem that I cannot do it faster in this case.
>
you probabaly need another inline function or micro here:
#define IsPawn(move) (piece(move.b.to) == PAWN)
If you are using VC, inline functions are prefered. You can easily browse these
inline fuctions. And the compiler does type checking that is certainly helpful.
>There are number of cases when I can do it faster for example if I check if the
>rank of to is the first rank but I also need special definitions for it.
>
>I guess that I will not change the defintion of to(m) to the better definition
>and for special cases I can add other definitions like
>#define rankto(i) i&(1<<12+1<<13+1<<14)
>
>#define rankto1 0
>#define rankto2 1<<12
>#define filetoa 0
>#define filetob 1<<9
>
>Here the numbers are not magiv numbers because we usually use numbers in chess
>but I still does not like these definitions.
>
>
>I think that I will do changing my data structure in some steps when the first
>step is the slow definition and using the slow definition for to(m) because
>changing too much at the same time is a sure way to get bugs.
>
>It means that the first step may make Movei slower and I need only to check that
>I did not do errors and only later it will become faster.
>
>I do not plan to add evaluation before I do it because it will do that work even
>harder.
>
>If I want to change my data structure then it is better to do it earlier even if
>it means smaller improvement in the near future relative to changing the
>evaluation.
>
>Uri
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