Document and cleanup new effective-single-reply code

[stockfish] / src / position.h

diff --git a/src/position.h b/src/position.h
index 370bb1d45e0476a9618c42725e350b7dc0e018e2..a1d53f042c8cb111124746c0b68919bb6285ddb5 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -63,6 +63,18 @@ const int MaxGameLength = 220;
 //// Types
 ////
 
+/// struct checkInfo is initialized at c'tor time and keeps
+/// info used to detect if a move gives check.
+
+struct CheckInfo {
+
+    CheckInfo(const Position&);
+
+    Square ksq;
+    Bitboard dcCandidates;
+    Bitboard checkSq[8];
+};
+
 /// Castle rights, encoded as bit fields
 
 enum CastleRights {
@@ -87,12 +99,13 @@ enum Phase {
 /// must be passed as a parameter.
 
 struct StateInfo {
-  Key key, pawnKey, materialKey;
-  int castleRights, rule50;
+  Key pawnKey, materialKey;
+  int castleRights, rule50, pliesFromNull;
   Square epSquare;
-  Value mgValue, egValue;
+  Score value;
   Value npMaterial[2];
 
+  Key key;
   PieceType capture;
   Bitboard checkersBB;
   StateInfo* previous;
@@ -202,11 +215,12 @@ public:
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
 
   // Properties of moves
-  bool pl_move_is_legal(Move m) const;
   bool pl_move_is_legal(Move m, Bitboard pinned) const;
+  bool pl_move_is_evasion(Move m, Bitboard pinned) const;
   bool move_is_check(Move m) const;
-  bool move_is_check(Move m, Bitboard dcCandidates) const;
+  bool move_is_check(Move m, const CheckInfo& ci) const;
   bool move_is_capture(Move m) const;
+  bool move_is_capture_or_promotion(Move m) const;
   bool move_is_passed_pawn_push(Move m) const;
   bool move_attacks_square(Move m, Square s) const;
 
@@ -222,7 +236,7 @@ public:
   // Doing and undoing moves
   void saveState();
   void do_move(Move m, StateInfo& st);
-  void do_move(Move m, StateInfo& st, Bitboard dcCandidates);
+  void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
   void undo_move(Move m);
   void do_null_move(StateInfo& st);
   void undo_null_move();
@@ -235,15 +249,14 @@ public:
 
   // Accessing hash keys
   Key get_key() const;
+  Key get_exclusion_key() const;
   Key get_pawn_key() const;
   Key get_material_key() const;
 
   // Incremental evaluation
-  Value mg_value() const;
-  Value eg_value() const;
+  Score value() const;
   Value non_pawn_material(Color c) const;
-  Phase game_phase() const;
-  template<GamePhase> Value pst_delta(Piece piece, Square from, Square to) const;
+  Score pst_delta(Piece piece, Square from, Square to) const;
 
   // Game termination checks
   bool is_mate() const;
@@ -283,9 +296,6 @@ private:
   void undo_castle_move(Move m);
   void find_checkers();
 
-  template<PieceType Piece>
-  void update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, Square to, Bitboard dcCandidates);
-
   template<bool FindPinned>
   Bitboard hidden_checkers(Color c) const;
 
@@ -295,8 +305,8 @@ private:
   Key compute_material_key() const;
 
   // Computing incremental evaluation scores and material counts
-  template<GamePhase> Value pst(Color c, PieceType pt, Square s) const;
-  template<GamePhase> Value compute_value() const;
+  Score pst(Color c, PieceType pt, Square s) const;
+  Score compute_value() const;
   Value compute_non_pawn_material(Color c) const;
 
   // Board
@@ -327,8 +337,8 @@ private:
   static Key zobCastle[16];
   static Key zobMaterial[2][8][16];
   static Key zobSideToMove;
-  static Value MgPieceSquareTable[16][64];
-  static Value EgPieceSquareTable[16][64];
+  static Score PieceSquareTable[16][64];
+  static Key zobExclusion;
 };
 
 
@@ -493,6 +503,10 @@ inline Key Position::get_key() const {
   return st->key;
 }
 
+inline Key Position::get_exclusion_key() const {
+  return st->key ^ zobExclusion;
+}
+
 inline Key Position::get_pawn_key() const {
   return st->pawnKey;
 }
@@ -501,46 +515,22 @@ inline Key Position::get_material_key() const {
   return st->materialKey;
 }
 
-template<Position::GamePhase Ph>
-inline Value Position::pst(Color c, PieceType pt, Square s) const {
-  return (Ph == MidGame ? MgPieceSquareTable[piece_of_color_and_type(c, pt)][s]
-                        : EgPieceSquareTable[piece_of_color_and_type(c, pt)][s]);
-}
-
-template<Position::GamePhase Ph>
-inline Value Position::pst_delta(Piece piece, Square from, Square to) const {
-  return (Ph == MidGame ? MgPieceSquareTable[piece][to] - MgPieceSquareTable[piece][from]
-                        : EgPieceSquareTable[piece][to] - EgPieceSquareTable[piece][from]);
+inline Score Position::pst(Color c, PieceType pt, Square s) const {
+  return PieceSquareTable[piece_of_color_and_type(c, pt)][s];
 }
 
-inline Value Position::mg_value() const {
-  return st->mgValue;
+inline Score Position::pst_delta(Piece piece, Square from, Square to) const {
+  return PieceSquareTable[piece][to] - PieceSquareTable[piece][from];
 }
 
-inline Value Position::eg_value() const {
-  return st->egValue;
+inline Score Position::value() const {
+  return st->value;
 }
 
 inline Value Position::non_pawn_material(Color c) const {
   return st->npMaterial[c];
 }
 
-inline Phase Position::game_phase() const {
-
-  // Values modified by Joona Kiiski
-  static const Value MidgameLimit = Value(15581);
-  static const Value EndgameLimit = Value(3998);
-
-  Value npm = non_pawn_material(WHITE) + non_pawn_material(BLACK);
-
-  if (npm >= MidgameLimit)
-      return PHASE_MIDGAME;
-  else if(npm <= EndgameLimit)
-      return PHASE_ENDGAME;
-  else
-      return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
-}
-
 inline bool Position::move_is_passed_pawn_push(Move m) const {
 
   Color c = side_to_move();
@@ -568,8 +558,13 @@ inline bool Position::has_pawn_on_7th(Color c) const {
 inline bool Position::move_is_capture(Move m) const {
 
   // Move must not be MOVE_NONE !
+  return (m & (3 << 15)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+}
 
-  return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(m);
+inline bool Position::move_is_capture_or_promotion(Move m) const {
+
+  // Move must not be MOVE_NONE !
+  return (m & (0x1F << 12)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
 }
 
 #endif // !defined(POSITION_H_INCLUDED)