/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#if !defined(PAWNS_H_INCLUDED)
+#ifndef PAWNS_H_INCLUDED
#define PAWNS_H_INCLUDED
+#include "misc.h"
#include "position.h"
-#include "tt.h"
#include "types.h"
-const int PawnTableSize = 16384;
+namespace Stockfish::Pawns {
-/// PawnInfo is a class which contains various information about a pawn
-/// structure. Currently, it only includes a middle game and an end game
-/// pawn structure evaluation, and a bitboard of passed pawns. We may want
-/// to add further information in the future. A lookup to the pawn hash
-/// table (performed by calling the pawn_info method in a PawnInfoTable
-/// object) returns a pointer to a PawnInfo object.
+/// Pawns::Entry contains various information about a pawn structure. A lookup
+/// to the pawn hash table (performed by calling the probe function) returns a
+/// pointer to an Entry object.
-class PawnInfo {
+struct Entry {
- friend class PawnInfoTable;
+ Score pawn_score(Color c) const { return scores[c]; }
+ Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
+ Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
+ Bitboard pawn_attacks_span(Color c) const { return pawnAttacksSpan[c]; }
+ int passed_count() const { return popcount(passedPawns[WHITE] | passedPawns[BLACK]); }
+ int blocked_count() const { return blockedCount; }
-public:
- Score pawns_value() const;
- Bitboard pawn_attacks(Color c) const;
- Bitboard passed_pawns(Color c) const;
- int file_is_half_open(Color c, File f) const;
- int has_open_file_to_left(Color c, File f) const;
- int has_open_file_to_right(Color c, File f) const;
+ template<Color Us>
+ Score king_safety(const Position& pos) {
+ return kingSquares[Us] == pos.square<KING>(Us) && castlingRights[Us] == pos.castling_rights(Us)
+ ? kingSafety[Us] : (kingSafety[Us] = do_king_safety<Us>(pos));
+ }
template<Color Us>
- Score king_shelter(const Position& pos, Square ksq);
+ Score do_king_safety(const Position& pos);
-private:
template<Color Us>
- Score updateShelter(const Position& pos, Square ksq);
+ Score evaluate_shelter(const Position& pos, Square ksq) const;
Key key;
- Bitboard passedPawns[2];
- Bitboard pawnAttacks[2];
- Square kingSquares[2];
- Score value;
- int halfOpenFiles[2];
- Score kingShelters[2];
-};
-
-
-/// The PawnInfoTable class represents a pawn hash table. The most important
-/// method is pawn_info, which returns a pointer to a PawnInfo object.
-
-class PawnInfoTable : public SimpleHash<PawnInfo, PawnTableSize> {
-public:
- PawnInfo* pawn_info(const Position& pos) const;
-
-private:
- template<Color Us>
- static Score evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi);
+ Score scores[COLOR_NB];
+ Bitboard passedPawns[COLOR_NB];
+ Bitboard pawnAttacks[COLOR_NB];
+ Bitboard pawnAttacksSpan[COLOR_NB];
+ Square kingSquares[COLOR_NB];
+ Score kingSafety[COLOR_NB];
+ int castlingRights[COLOR_NB];
+ int blockedCount;
};
+typedef HashTable<Entry, 131072> Table;
-inline Score PawnInfo::pawns_value() const {
- return value;
-}
-
-inline Bitboard PawnInfo::pawn_attacks(Color c) const {
- return pawnAttacks[c];
-}
-
-inline Bitboard PawnInfo::passed_pawns(Color c) const {
- return passedPawns[c];
-}
-
-inline int PawnInfo::file_is_half_open(Color c, File f) const {
- return halfOpenFiles[c] & (1 << int(f));
-}
-
-inline int PawnInfo::has_open_file_to_left(Color c, File f) const {
- return halfOpenFiles[c] & ((1 << int(f)) - 1);
-}
-
-inline int PawnInfo::has_open_file_to_right(Color c, File f) const {
- return halfOpenFiles[c] & ~((1 << int(f+1)) - 1);
-}
+Entry* probe(const Position& pos);
-template<Color Us>
-inline Score PawnInfo::king_shelter(const Position& pos, Square ksq) {
- return kingSquares[Us] == ksq ? kingShelters[Us] : updateShelter<Us>(pos, ksq);
-}
+} // namespace Stockfish::Pawns
-#endif // !defined(PAWNS_H_INCLUDED)
+#endif // #ifndef PAWNS_H_INCLUDED