MovePicker: avoid calling see() for LxH and equal captures
authorMarco Costalba <mcostalba@gmail.com>
Fri, 5 Dec 2008 11:00:30 +0000 (12:00 +0100)
committerMarco Costalba <mcostalba@gmail.com>
Sat, 6 Dec 2008 10:37:19 +0000 (11:37 +0100)
No functional change but should speed-up the captures scoring.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
src/movepick.cpp

index d4242a300de7620e5f58665cb20c7e5ff0aa102c..95bbddba670788af7d2b937a72ddb4c28a791a31 100644 (file)
@@ -228,18 +228,29 @@ void MovePicker::score_captures() {
   // to the badCaptures[] array.
   Move m;
   int seeValue;
+  Square from, to;
 
   for (int i = 0; i < numOfMoves; i++)
   {
       m = moves[i].move;
-      seeValue = pos.see(m);
+      from = move_from(m);
+      to = move_to(m);
+
+      bool hxl = ( int(pos.midgame_value_of_piece_on(from))
+                  -int(pos.midgame_value_of_piece_on(to)) > 0)
+                || pos.type_of_piece_on(from) == KING;
+
+      // Avoid calling see() for LxH and equal captures because
+      // SEE is always >= 0 and we order for MVV/LVA anyway.
+      seeValue = (hxl ? pos.see(m) : 0);
+
       if (seeValue >= 0)
       {
           if (move_promotion(m))
               moves[i].score = QueenValueMidgame;
           else
-              moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
-                              -int(pos.type_of_piece_on(move_from(m)));
+              moves[i].score = int(pos.midgame_value_of_piece_on(to))
+                              -int(pos.type_of_piece_on(from));
       }
       else
       {