Move Tempo to evaluation

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index 8b043af83b4a0826c0d0fe52000bce970cce9c79..e89477ea534d654658244d890c53d9ead3e87b07 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -62,15 +62,8 @@ const Value PieceValueEndgame[17] = {
   RookValueEndgame, QueenValueEndgame
 };
 
-
-namespace {
-
-  // Bonus for having the side to move (modified by Joona Kiiski)
-  const Score Tempo = make_score(48, 22);
-
-  // To convert a Piece to and from a FEN char
-  const string PieceToChar(" PNBRQK  pnbrqk  .");
-}
+// To convert a Piece to and from a FEN char
+static const string PieceToChar(" PNBRQK  pnbrqk  .");
 
 
 /// CheckInfo c'tor
@@ -830,7 +823,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   prefetch((char*)TT.first_entry(k));
 
   // Move the piece
-  Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+  Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
   byTypeBB[ALL_PIECES] ^= from_to_bb;
   byTypeBB[pt] ^= from_to_bb;
   byColorBB[us] ^= from_to_bb;
@@ -934,9 +927,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
       }
   }
 
-  // Finish
   sideToMove = ~sideToMove;
-  st->psqScore += (sideToMove == WHITE ?  Tempo : -Tempo);
 
   assert(pos_is_ok());
 }
@@ -995,7 +986,7 @@ void Position::undo_move(Move m) {
   }
 
   // Put the piece back at the source square
-  Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+  Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
   byTypeBB[ALL_PIECES] ^= from_to_bb;
   byTypeBB[pt] ^= from_to_bb;
   byColorBB[us] ^= from_to_bb;
@@ -1078,21 +1069,13 @@ void Position::do_castle_move(Move m) {
   assert(piece_on(kfrom) == make_piece(us, KING));
   assert(piece_on(rfrom) == make_piece(us, ROOK));
 
-  // Remove pieces from source squares
-  byTypeBB[ALL_PIECES] ^= kfrom;
-  byTypeBB[KING] ^= kfrom;
-  byColorBB[us] ^= kfrom;
-  byTypeBB[ALL_PIECES] ^= rfrom;
-  byTypeBB[ROOK] ^= rfrom;
-  byColorBB[us] ^= rfrom;
-
-  // Put pieces on destination squares
-  byTypeBB[ALL_PIECES] |= kto;
-  byTypeBB[KING] |= kto;
-  byColorBB[us] |= kto;
-  byTypeBB[ALL_PIECES] |= rto;
-  byTypeBB[ROOK] |= rto;
-  byColorBB[us] |= rto;
+  // Move the pieces, with some care; in chess960 could be kto == rfrom
+  Bitboard k_from_to_bb = SquareBB[kfrom] ^ SquareBB[kto];
+  Bitboard r_from_to_bb = SquareBB[rfrom] ^ SquareBB[rto];
+  byTypeBB[KING] ^= k_from_to_bb;
+  byTypeBB[ROOK] ^= r_from_to_bb;
+  byTypeBB[ALL_PIECES] ^= k_from_to_bb ^ r_from_to_bb;
+  byColorBB[us] ^= k_from_to_bb ^ r_from_to_bb;
 
   // Update board
   Piece king = make_piece(us, KING);
@@ -1135,9 +1118,7 @@ void Position::do_castle_move(Move m) {
       // Update checkers BB
       st->checkersBB = attackers_to(king_square(~us)) & pieces(us);
 
-      // Finish
       sideToMove = ~sideToMove;
-      st->psqScore += (sideToMove == WHITE ?  Tempo : -Tempo);
   }
   else
       // Undo: point our state pointer back to the previous state
@@ -1180,7 +1161,6 @@ void Position::do_null_move(StateInfo& backupSt) {
       st->epSquare = SQ_NONE;
       st->rule50++;
       st->pliesFromNull = 0;
-      st->psqScore += (sideToMove == WHITE ?  Tempo : -Tempo);
   }
 
   assert(pos_is_ok());
@@ -1414,18 +1394,15 @@ Key Position::compute_material_key() const {
 /// updated by do_move and undo_move when the program is running in debug mode.
 Score Position::compute_psq_score() const {
 
-  Bitboard b;
   Score result = SCORE_ZERO;
+  Bitboard b = pieces();
 
-  for (Color c = WHITE; c <= BLACK; c++)
-      for (PieceType pt = PAWN; pt <= KING; pt++)
-      {
-          b = pieces(pt, c);
-          while (b)
-              result += pieceSquareTable[make_piece(c, pt)][pop_1st_bit(&b)];
-      }
+  while (b)
+  {
+      Square s = pop_1st_bit(&b);
+      result += pieceSquareTable[piece_on(s)][s];
+  }
 
-  result += (sideToMove == WHITE ? Tempo / 2 : -Tempo / 2);
   return result;
 }