A better contempt implementation for Stockfish (#1325)

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index e470e61350ca268fdced0c37e8b186448aed535b..9f50ded6c2455b0b359d92e4f1740ada923b9fe1 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -253,9 +253,9 @@ namespace {
   template<Tracing T> template<Color Us>
   void Evaluation<T>::initialize() {
 
-    const Color  Them = (Us == WHITE ? BLACK : WHITE);
-    const Square Up   = (Us == WHITE ? NORTH : SOUTH);
-    const Square Down = (Us == WHITE ? SOUTH : NORTH);
+    const Color     Them = (Us == WHITE ? BLACK : WHITE);
+    const Direction Up   = (Us == WHITE ? NORTH : SOUTH);
+    const Direction Down = (Us == WHITE ? SOUTH : NORTH);
     const Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB);
 
     // Find our pawns on the first two ranks, and those which are blocked
@@ -372,7 +372,7 @@ namespace {
                 && pos.is_chess960()
                 && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
             {
-                Square d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
+                Direction d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
                 if (pos.piece_on(s + d) == make_piece(Us, PAWN))
                     score -= !pos.empty(s + d + pawn_push(Us))                ? TrappedBishopA1H1 * 4
                             : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2
@@ -422,10 +422,10 @@ namespace {
   template<Tracing T>  template<Color Us>
   Score Evaluation<T>::evaluate_king() {
 
-    const Color Them    = (Us == WHITE ? BLACK : WHITE);
-    const Square Up     = (Us == WHITE ? NORTH : SOUTH);
-    const Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
-                                       : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
+    const Color     Them = (Us == WHITE ? BLACK : WHITE);
+    const Direction Up   = (Us == WHITE ? NORTH : SOUTH);
+    const Bitboard  Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
+                                        : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
 
     const Square ksq = pos.square<KING>(Us);
     Bitboard weak, b, b1, b2, safe, other;
@@ -530,11 +530,11 @@ namespace {
   template<Tracing T>  template<Color Us>
   Score Evaluation<T>::evaluate_threats() {
 
-    const Color Them        = (Us == WHITE ? BLACK      : WHITE);
-    const Square Up         = (Us == WHITE ? NORTH      : SOUTH);
-    const Square Left       = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
-    const Square Right      = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
-    const Bitboard TRank3BB = (Us == WHITE ? Rank3BB    : Rank6BB);
+    const Color     Them     = (Us == WHITE ? BLACK      : WHITE);
+    const Direction Up       = (Us == WHITE ? NORTH      : SOUTH);
+    const Direction Left     = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
+    const Direction Right    = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
+    const Bitboard  TRank3BB = (Us == WHITE ? Rank3BB    : Rank6BB);
 
     Bitboard b, weak, defended, stronglyProtected, safeThreats;
     Score score = SCORE_ZERO;
@@ -636,8 +636,8 @@ namespace {
   template<Tracing T>  template<Color Us>
   Score Evaluation<T>::evaluate_passed_pawns() {
 
-    const Color Them = (Us == WHITE ? BLACK : WHITE);
-    const Square Up  = (Us == WHITE ? NORTH : SOUTH);
+    const Color     Them = (Us == WHITE ? BLACK : WHITE);
+    const Direction Up   = (Us == WHITE ? NORTH : SOUTH);
 
     Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares;
     Score score = SCORE_ZERO;
@@ -840,7 +840,7 @@ namespace {
     // Initialize score by reading the incrementally updated scores included in
     // the position object (material + piece square tables) and the material
     // imbalance. Score is computed internally from the white point of view.
-    Score score = pos.psq_score() + me->imbalance();
+    Score score = pos.psq_score() + me->imbalance() + Eval::Contempt;
 
     // Probe the pawn hash table
     pe = Pawns::probe(pos);
@@ -903,6 +903,7 @@ namespace {
 
 } // namespace
 
+Score Eval::Contempt = SCORE_ZERO;
 
 /// evaluate() is the evaluator for the outer world. It returns a static evaluation
 /// of the position from the point of view of the side to move.