Author: Uri Blass
Date: 04:13:58 02/20/03
Go up one level in this thread
On February 20, 2003 at 06:54:01, Filip Tvrzsky wrote:
>On February 20, 2003 at 06:26:39, Uri Blass wrote:
>
>>On February 19, 2003 at 10:45:27, Dezhi Zhao wrote:
>>
>>>On February 19, 2003 at 09:57:13, Uri Blass wrote:
>>>
>>>>On February 19, 2003 at 09:41:35, Dezhi Zhao wrote:
>>>>
>>>>>On February 19, 2003 at 06:39:49, Uri Blass wrote:
>>>>>
>>>>>>I try to do movei faster and there are things that are supposed to do it
>>>>>>slightly faster but for some reasons do it slower so I deleted them(Maybe it is
>>>>>>better if I ignore it because it is a compiler optimization noise but I do not
>>>>>>like to see the program slower even if it is only 0.1% slower).
>>>>>>
>>>>>>Note that I do not use now compiler optimization except optimize for speed with
>>>>>>visual C++6.
>>>>>>
>>>>>>
>>>>>>Here is an example:
>>>>>>My function of adding pawn moves to the stack of moves get 2 numbers(from,to).
>>>>>>
>>>>>>I found that special functions to generate white moves one square forward,white
>>>>>>moves 2 pawns forward,black pawns one square forward,...helped me to do movei
>>>>>>faster.
>>>>>>
>>>>>>Common sense say that now I do not need 2 numbers in my functions because
>>>>>>I always have to=from-8 in
>>>>>>
>>>>>>Here is my function.
>>>>>>to is always from-8 and the question is if I can take advantage of that fact.
>>>>>>
>>>>>>static void gen_quietblackslowpawns(int from,int to)
>>>>>>{
>>>>>> gen_t *g;
>>>>>> if (to<=7)
>>>>>> {
>>>>>> gen_promote(from,to);
>>>>>> return;
>>>>>> }
>>>>>> g=&gen_dat[first_move[ply+1]++];
>>>>>> g->m.b.from=(char)from;
>>>>>> g->m.b.to=(char) to;
>>>>>> g->m.b.promote=0;
>>>>>> g->m.b.bits=16;
>>>>>> #if MODE!=MODE_PERFT
>>>>>> g->score = history[from][to];
>>>>>> g->index=-10000;
>>>>>> #endif
>>>>>>}
>>>>>
>>>>>I think you can get a little from that fact. It will save a few push and pop
>>>>>operations.
>>>>>
>>>>>By the way, if you really want to optimize this function, you should consider
>>>>>re-designing the b structure so that the move can be saved in a single write
>>>>>operation, instead of 4.
>>>>
>>>>Thanks for the advise but how do I do it
>>>>
>>>>I have the same data structure as tscp here(Note that 90% of my code is
>>>>different than tscp but I copied part of it's data structures).
>>>>
>>>>Here is my b structure
>>>>
>>>>typedef struct
>>>>{
>>>> char from;
>>>> char to;
>>>> char promote;
>>>> char bits;
>>>>}
>>>>move_bytes;
>>>>
>>>>typedef union
>>>>{
>>>> move_bytes b;
>>>> int u;
>>>>}
>>>>move;
>>>>
>>>>
>>>>I can think about deleting the b and have something like
>>>>g->m.u=from+(to<<8)+(promote<<16)+bits<<24) but the question in that case is if
>>>
>>>yes. you can go this way. for this function, the last 2 items are simple
>>>constants anyways.
>>>
>>>>it is not going to do accesing the varaibles slower because there are places in
>>>>the code when I use bits and now I will need to use things like u>>24.
>>>>
>>>>I have no idea about the price of these things so I cannot evaluate speed here.
>>>>
>>>>Uri
>>>
>>>Not that complicated if you think it twice. I do know the semantics of bits
>>>thare. However I assume it is a flag. If it is the case, you do not need to do a
>>>shift to make it flat. Consider testing the other way without shift operations:
>>>u & (16 << 24)
>>>So you can avoid shift operations in many cases. So you still gain something
>>>here.
>>>
>>>dzhao
>>
>>I try it at this moment(I do not know if it is going to make the code faster so
>>I saved the previous code).
>>
>>The problem is how to make my code readable at the same time.
>>
>>I deleted the m.u and m.b.from,m.b,to,...
>>and have only m that is an integer.
>>
>>I try to use some defines
>>
>>#define mfrom (m&63)
>>#define mto ((m>>8)&63)
>>#define mpromote ((m>>16)&63)
>>#define mbits ((m>>24)&63)
>>
>>It was not enough so I added the following defines
>>
>>#define gen_dat_i_mfrom (gen_dat[i].m&63)
>>#define gen_dat_i_mto ((gen_dat[i].m>>8)&63)
>>#define gen_dat_i_mpromote ((gen_dat[i].m>>16)&63)
>>#define gen_dat_i_mbits ((gen_dat[i].m>>24)&63)
>>
>>I see that it is not enough and I need the same for other varaibles that are of
>>the same type.
>>
>>I do not like it so I went back to my previous code
>>
>>Thanks in advance for advices.
>>
>>Uri
>
>Why do you not use inline functions? I think this is just the case to employ
>them.
>I have such a code in my engine:
> inline unsigned char From(MOVE x) { return (unsigned char) ((x >> 8) & 0x77);
>}
>and so on.
>Filip
I do not know how to use inline functions.
Note that I learned only C and not C++
Is it possible in C?
I do not find the word inline in the index of the book (The C programming
Language).
I get errors if I try to add the words inline before a function
error C2054: expected '(' to follow 'inline'
or if I put inline before the '(' I get
error C2061: syntax error : identifier 'inline'
I also do not understand how inline function can help me to get rid of my
structure and to replace the tscp structure by a better structure.
Uri
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