Speed up Gnuchess

[Vincent Diepeveen]

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: vdie...@cs.ruu.nl
--
+======================================+
|| Groeten, Vincent. ||
+--------------------------------------+
|| email : vdie...@cs.ruu.nl ||