🚀 go-pugleaf

Hello,

I discovered in GNU-chess v 4.0 (for dos)
something that can be speeded up( i am sorry for my bad
english ), hopefully i didn't find out the speed-up as second, 
however it is a little speed up, but highly effective in 
Nullmove/Quiescence search, as there will be captured many 
pieces over there.

In UpdatePieceList( .. ) you can see something like

UpdatePieceList( short int sq, short int iop .. ) {
  short int i;
  ..

  if( iop == 1 ) { /* remove a piece from the piecelist */
    ..
    for( i = Pindex[ sq ] ; i < PieceCnt[ side ] ; i++ ) {
      Pindex[ i ] = i;
      PieceList[ side ][ i ] = PieceList[ side ][ i+1 ];
    }
   ...
  }
  else {
  ..
  ..
  }
}

This slow 'shifting up the array PieceList' to fill the hole
PieceList[ side ][ i ] is not practically.
It is easier and faster to say just:

 ..
 if( iop == 1 ) {
   i = Pindex[ sq ];
   if( i < PieceCnt[ side ] ) {
     PieceList[ side ][ i ] = PieceList[ side ][ PieceCnt[ side ] ];
     Pindex[ PieceList[ side ][ i ] ] = i;
   }
   PieceCnt[ side ]--;    
 }
 else {...
 ....

Greetings, Vincent Diepeveen.

email: vdiepeve@cs.ruu.nl


--
                +--------------------------------------+
                ||  email  : vdiepeve@cs.ruu.nl       ||
                ||  fidonet: 2:280/206.23             ||
                +======================================+