Refactor pawns shelter and storm

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 2903c4b375da81736478ee3fb6439e6f2f749c08..0a500c92ebbf4c8ef69c4288ab81638fa6f94e30 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -167,8 +167,8 @@ namespace {
   // happen in Chess960 games.
   const Score TrappedBishopA1H1Penalty = make_score(100, 100);
 
-  // Penalty for a minor piece that is not defended by anything
-  const Score UndefendedMinorPenalty = make_score(25, 10);
+  // Penalty for BNR that is not defended by anything
+  const Score UndefendedPiecePenalty = make_score(25, 10);
 
   // The SpaceMask[Color] contains the area of the board which is considered
   // by the space evaluation. In the middle game, each side is given a bonus
@@ -357,13 +357,12 @@ namespace {
 template<bool Trace>
 Value do_evaluate(const Position& pos, Value& margin) {
 
+  assert(!pos.in_check());
+
   EvalInfo ei;
   Value margins[2];
   Score score, mobilityWhite, mobilityBlack;
 
-  assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
-  assert(!pos.in_check());
-
   // Initialize score by reading the incrementally updated scores included
   // in the position object (material + piece square tables).
   score = pos.value();
@@ -679,21 +678,24 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard b;
+    Bitboard b, undefended, undefendedMinors, weakEnemies;
     Score score = SCORE_ZERO;
 
-    // Undefended minors get penalized even if not under attack
-    Bitboard undefended =  pos.pieces(Them)
-                         & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
-                         & ~ei.attackedBy[Them][0];
-    if (undefended)
-        score += single_bit(undefended) ? UndefendedMinorPenalty
-                                        : UndefendedMinorPenalty * 2;
+    // Undefended pieces get penalized even if not under attack
+    undefended = pos.pieces(Them) & ~ei.attackedBy[Them][0];
+    undefendedMinors = undefended & (pos.pieces(BISHOP) | pos.pieces(KNIGHT));
+
+    if (undefendedMinors)
+        score += single_bit(undefendedMinors) ? UndefendedPiecePenalty
+                                              : UndefendedPiecePenalty * 2;
+    if (undefended & pos.pieces(ROOK))
+        score += UndefendedPiecePenalty;
 
     // Enemy pieces not defended by a pawn and under our attack
-    Bitboard weakEnemies =  pos.pieces(Them)
-                          & ~ei.attackedBy[Them][PAWN]
-                          & ei.attackedBy[Us][0];
+    weakEnemies =  pos.pieces(Them)
+                 & ~ei.attackedBy[Them][PAWN]
+                 & ei.attackedBy[Us][0];
+
     if (!weakEnemies)
         return score;
 
@@ -749,8 +751,8 @@ Value do_evaluate(const Position& pos, Value& margin) {
     int attackUnits;
     const Square ksq = pos.king_square(Us);
 
-    // King shelter
-    Score score = ei.pi->king_shelter<Us>(pos, ksq);
+    // King shelter and enemy pawns storm
+    Score score = ei.pi->king_safety<Us>(pos, ksq);
 
     // King safety. This is quite complicated, and is almost certainly far
     // from optimally tuned.
@@ -772,7 +774,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
         attackUnits =  std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
                      + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
                      + InitKingDanger[relative_square(Us, ksq)]
-                     - mg_value(ei.pi->king_shelter<Us>(pos, ksq)) / 32;
+                     - mg_value(ei.pi->king_safety<Us>(pos, ksq)) / 32;
 
         // Analyse enemy's safe queen contact checks. First find undefended
         // squares around the king attacked by enemy queen...