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Subject: Re: A faster move generator than previously known

Author: Vincent Diepeveen

Date: 04:40:14 08/08/03

Go up one level in this thread


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.

>  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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