Fix endless reaparenting loop

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 849185b67e497246048fdf508e040b1cf58b48b4..6f6141bafd37e0c3f0701376cd47f8a85523e107 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -150,6 +150,9 @@ namespace {
 
   #undef S
 
+  // Bonus for having the side to move (modified by Joona Kiiski)
+  const Score Tempo = make_score(24, 11);
+
   // Rooks and queens on the 7th rank (modified by Joona Kiiski)
   const Score RookOn7thBonus  = make_score(47, 98);
   const Score QueenOn7thBonus = make_score(27, 54);
@@ -362,14 +365,15 @@ Value do_evaluate(const Position& pos, Value& margin) {
   Value margins[2];
   Score score, mobilityWhite, mobilityBlack;
 
-  // Initialize score by reading the incrementally updated scores included
-  // in the position object (material + piece square tables).
-  score = pos.psq_score();
-
   // margins[] store the uncertainty estimation of position's evaluation
   // that typically is used by the search for pruning decisions.
   margins[WHITE] = margins[BLACK] = VALUE_ZERO;
 
+  // Initialize score by reading the incrementally updated scores included
+  // in the position object (material + piece square tables) and adding
+  // Tempo bonus. Score is computed from the point of view of white.
+  score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
+
   // Probe the material hash table
   ei.mi = pos.this_thread()->materialTable.probe(pos);
   score += ei.mi->material_value();
@@ -577,7 +581,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
             assert(b);
 
-            if (single_bit(b) && (b & pos.pieces(Them)))
+            if (!more_than_one(b) && (b & pos.pieces(Them)))
                 score += ThreatBonus[Piece][type_of(pos.piece_on(first_1(b)))];
         }
 
@@ -685,8 +689,8 @@ Value do_evaluate(const Position& pos, Value& margin) {
                       & ~ei.attackedBy[Them][0];
 
     if (undefendedMinors)
-        score += single_bit(undefendedMinors) ? UndefendedMinorPenalty
-                                              : UndefendedMinorPenalty * 2;
+        score += more_than_one(undefendedMinors) ? UndefendedMinorPenalty * 2
+                                                 : UndefendedMinorPenalty;
 
     // Enemy pieces not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)
@@ -892,14 +896,14 @@ Value do_evaluate(const Position& pos, Value& margin) {
             // If the pawn is free to advance, increase bonus
             if (pos.square_empty(blockSq))
             {
-                squaresToQueen = squares_in_front_of(Us, s);
+                squaresToQueen = forward_bb(Us, s);
                 defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
 
                 // If there is an enemy rook or queen attacking the pawn from behind,
                 // add all X-ray attacks by the rook or queen. Otherwise consider only
                 // the squares in the pawn's path attacked or occupied by the enemy.
-                if (   (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them))
-                    && (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
+                if (   (forward_bb(Them, s) & pos.pieces(ROOK, QUEEN, Them))
+                    && (forward_bb(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from<ROOK>(s)))
                     unsafeSquares = squaresToQueen;
                 else
                     unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
@@ -974,7 +978,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
         {
             s = pop_1st_bit(&b);
             queeningSquare = relative_square(c, make_square(file_of(s), RANK_8));
-            queeningPath = squares_in_front_of(c, s);
+            queeningPath = forward_bb(c, s);
 
             // Compute plies to queening and check direct advancement
             movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
@@ -1022,7 +1026,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
         // Check if (without even considering any obstacles) we're too far away or doubled
         if (   pliesToQueen[winnerSide] + 3 <= pliesToGo
-            || (squares_in_front_of(loserSide, s) & pos.pieces(PAWN, loserSide)))
+            || (forward_bb(loserSide, s) & pos.pieces(PAWN, loserSide)))
             candidates ^= s;
     }
 
@@ -1046,7 +1050,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
         // Generate list of blocking pawns and supporters
         supporters = adjacent_files_bb(file_of(s)) & candidates;
-        opposed = squares_in_front_of(loserSide, s) & pos.pieces(PAWN, winnerSide);
+        opposed = forward_bb(loserSide, s) & pos.pieces(PAWN, winnerSide);
         blockers = passed_pawn_mask(loserSide, s) & pos.pieces(PAWN, winnerSide);
 
         assert(blockers);