Author: Uri Blass
Date: 04:57:47 02/20/03
Go up one level in this thread
On February 20, 2003 at 07:43:29, Filip Tvrzsky wrote: >On February 20, 2003 at 07:13:58, Uri Blass wrote: > >>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 > >Sorry, I have noticed your mention about Visual C++ compiler, so assumed using >C++ language ... Of course you can't use inline functions in C. But I suppose >you to learn little bit about this C++ feature and maybe few others. You don't >need learn that OOP stuff, just how to use C++ like improved C. >For C language is there another solution - macros with parametres: > #define bits(x) ((x>>24)&63) >Now you can write simply bits(m) or bits(gen_dat[i].m) or whatever you want. >Filip Thanks I used that trick in other defines but did not think to do it here. I hope that it is going to help me. Uri
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