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Subject: Re: A faster move generator than previously known

Author: José Carlos

Date: 04:46:17 08/08/03

Go up one level in this thread


On August 08, 2003 at 07:40:14, Vincent Diepeveen wrote:

>On August 08, 2003 at 02:50:01, José Carlos wrote:
>
>>On August 07, 2003 at 23:48:51, Vincent Diepeveen wrote:
>>
>>
>>  I've tried something like that in the past. My move generator is faster that
>>this one. In my other program (with non rotated bitboards) the move generator
>>alone is slower, but I can calculate many things very cheap. If I try to do in
>>my 0x88 program all the stuff I do in my bitboard program, it gets twice slower
>>instantly.
>
>
>
>>  Feel free to say that this happens because I'm a very bad programmer, if you
>>feel better that way.
>
>Yes you are a very poor programmer unless you tested at a 486.
>
>You hardly have branch mispredictions with this move generator in case you
>didn't notice. So it kicks the hell out of anything you do in advance,
>because 2 branch mispredictions is already more expensive than generating
>1 move with this generator.

  Thanks for the (expected) compliment.
  I have zero branch mispredictions in my current move generator.

  José C.


>>  José C.
>>
>>
>>
>>
>>>You guys can figure out the rest i bet seeing this code.
>>>
>>>All that bitboard idiocy always. This kicks the hell out of it.
>>>
>>>Vincent Diepeveen,
>>>8 august 2003  5:53 AM
>>>
>>>#if MSVC
>>>__inline
>>>#endif
>>>void GenMovesI(RecursionBlock *rb,int sq) {
>>>  int SRsq,piece,u,xside,*s,*t,side,*v,*w;
>>>
>>>  side  = rb->side;
>>>  xside = rb->xside;
>>>  SRsq  = (sq<<6);
>>>  piece = board[sq];
>>>  if( piece == pawn ) {
>>>    v = ipiecepos[side][sq];
>>>    w = ipawndir[side][sq];
>>>    u = *v++;
>>>    if( row(u) != 0 && row(u) != 7 ) {
>>>      if( color[u] == neutral) {
>>>        rb->zetend->zet = (SRsq|u);
>>>        rb->zetend++;
>>>        if( (u=*v) != 128 && color[u] == neutral ) { /* indien u == sq dan false
>>>*/
>>>          rb->zetend->zet = (SRsq|u);
>>>          rb->zetend++;
>>>        }
>>>      }
>>>
>>>      u = *w++;
>>>      if( color[u] == xside ) {/* ppos bevat geen 100, maar sq. */
>>>        rb->zetend->zet = (SRsq|u|move_captures);
>>>        rb->zetend++;
>>>      }
>>>      if( (u=*w) != 128 && color[u] == xside ) {
>>>        rb->zetend->zet = (SRsq|u|move_captures);
>>>        rb->zetend++;
>>>      }
>>>    }
>>>    else {
>>>      if( color[u] == neutral) {
>>>        rb->zetend->zet = (SRsq|u|move_pqueen);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_pknight);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_prook);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_pbishop);
>>>        rb->zetend++;
>>>      }
>>>      u = *w++;
>>>      if( color[u] == xside) {/* captures */
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_pqueen);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_pknight);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_prook);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_pbishop);
>>>        rb->zetend++;
>>>      }
>>>      if( (u=*w) != 128 && color[u] == xside) {
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_pqueen);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_pknight);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_prook);
>>>        rb->zetend++;
>>>        rb->zetend->zet = (SRsq|u|move_captures|move_pbishop);
>>>        rb->zetend++;
>>>      }
>>>    }
>>>  }
>>>  else {
>>>    t = cancapside[side];
>>>    if( sweep[piece] ) {
>>>      int *vh,*wh,uh;
>>>      s  = andscan[0];
>>>      vh = ipiecepos[piece][sq];
>>>      wh = iskippos[sq];
>>>      uh = *vh++;
>>>      do {
>>>        int p1=snelbord[uh],sh=wh[uh]; /* local variables is faster for GCC/MSVC
>>>*/
>>>        vh += (s[p1]&sh);
>>>        if( color[uh] != side ) {
>>>          rb->zetend->zet = (SRsq|uh|t[p1]);
>>>          rb->zetend++;
>>>        }
>>>      } while( (uh=*vh++) != 128 );
>>>
>>>      /*vi = gentable[piece-3][sq];
>>>      s  = doorscan[0];
>>>      u  = vi[sq];
>>>      do {
>>>        if( color[u] != side ) {
>>>          cappiece = snelbord[u];
>>>          rb->zetend->zet = (SRsq|u|t[cappiece]);
>>>          rb->zetend++;
>>>          u = vi[(s[cappiece]|u)];
>>>        }
>>>        else {
>>>          u = vi[(64|u)];
>>>        }
>>>      } while( u != 128 );*/
>>>    }
>>>    else {
>>>      v = ipiecepos[piece][sq];
>>>      u = *v++;
>>>      do {
>>>        if( color[u] != side ) {
>>>          rb->zetend->zet = (SRsq|u|t[snelbord[u]]);
>>>          rb->zetend++;
>>>        }
>>>      } while( (u=*v++) != 128 );
>>>    }
>>>  }
>>>}
>>>
>>>void MoveListI(RecursionBlock *rb,struct Move *CFEP) {
>>>/* Generate all semi-legal moves. Check is ignored.
>>>*/
>>>  int f,to,from,u,*psq,*pend,*w;
>>>
>>>  to = CFEP->zet&63;
>>>  rb->zetend = rb->SemiLegals;
>>>  if( board[to] == pawn ) { /* for enpassant */
>>>    from = (CFEP->zet>>6)&63;
>>>    if( to-from == 16 || from-to == 16 ) {
>>>      f = (to+from)>>1;
>>>      w = ipawndir[rb->xside][f];
>>>      u = *w++;
>>>      if( color[u] == rb->side && board[u] == pawn ) {
>>>        rb->zetend->zet = ((u<<6)|f|move_captures|move_enpassant);
>>>        rb->zetend++;
>>>      }
>>>      if( (u=*w) != 128 && color[u] == rb->side && board[u] == pawn ) {
>>>        rb->zetend->zet = ((u<<6)|f|move_captures|move_enpassant);
>>>        rb->zetend++;
>>>      }
>>>    }
>>>  }
>>>
>>>  psq  = PieceList[rb->side];
>>>  pend = PieceList[rb->side]+PieceMax[rb->side];
>>>  if( !castld[rb->side] ) {
>>>    u = *psq;
>>>    if( castle(rb->side,u,u+2) ) {
>>>      rb->zetend->zet = ((u<<6)|(u+2)|move_castles);
>>>      rb->zetend++;
>>>    }
>>>    if( castle(rb->side,u,u-2) ) {
>>>      rb->zetend->zet = ((u<<6)|(u-2)|move_castles);
>>>      rb->zetend++;
>>>    }
>>>  }
>>>
>>>  #if BOUNDSCHECKING
>>>  pend++;
>>>  do {
>>>    pend--;
>>>    if( *pend != 64 )
>>>      GenMovesI(rb,*pend);
>>>  } while( pend > psq );
>>>  #else
>>>  do {
>>>    if( *pend != 64 )
>>>      GenMovesI(rb,*pend);
>>>  } while( --pend >= psq );
>>>  #endif
>>>} /* End MoveList() */



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