along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
#if !defined(PAWNS_H_INCLUDED)
#define PAWNS_H_INCLUDED
-////
-//// Includes
-////
-
#include "bitboard.h"
-#include "value.h"
-
-////
-//// Types
-////
+#include "position.h"
+#include "tt.h"
+#include "types.h"
const int PawnTableSize = 16384;
/// to add further information in the future. A lookup to the pawn hash table
/// (performed by calling the get_pawn_info method in a PawnInfoTable object)
/// returns a pointer to a PawnInfo object.
-class Position;
-
class PawnInfo {
friend class PawnInfoTable;
public:
Score pawns_value() const;
- Value kingside_storm_value(Color c) const;
- Value queenside_storm_value(Color c) 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;
- Score king_shelter(const Position& pos, Color c, Square ksq);
+
+ template<Color Us>
+ Score king_shelter(const Position& pos, Square ksq);
private:
- Score updateShelter(const Position& pos, Color c, Square ksq);
+ template<Color Us>
+ Score updateShelter(const Position& pos, Square ksq);
Key key;
Bitboard passedPawns[2];
Bitboard pawnAttacks[2];
Square kingSquares[2];
Score value;
- int ksStormValue[2];
- int qsStormValue[2];
int halfOpenFiles[2];
Score kingShelters[2];
};
-/// The PawnInfoTable class represents a pawn hash table. It is basically
-/// just an array of PawnInfo objects and a few methods for accessing these
-/// objects. The most important method is get_pawn_info, which looks up a
-/// position in the table and returns a pointer to a PawnInfo object.
-class PawnInfoTable {
+/// The PawnInfoTable class represents a pawn hash table. The most important
+/// method is get_pawn_info, which returns a pointer to a PawnInfo object.
+
+class PawnInfoTable : public SimpleHash<PawnInfo, PawnTableSize> {
enum SideType { KingSide, QueenSide };
public:
- PawnInfoTable();
- ~PawnInfoTable();
PawnInfo* get_pawn_info(const Position& pos) const;
void prefetch(Key key) const;
private:
template<Color Us>
Score evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi) const;
-
- template<Color Us, SideType Side>
- int evaluate_pawn_storm(Square s, Rank r, File f, Bitboard theirPawns) const;
-
- PawnInfo* entries;
};
-
-////
-//// Inline functions
-////
+inline Square pawn_push(Color c) {
+ return c == WHITE ? DELTA_N : DELTA_S;
+}
inline void PawnInfoTable::prefetch(Key key) const {
return pawnAttacks[c];
}
-inline Value PawnInfo::kingside_storm_value(Color c) const {
- return Value(ksStormValue[c]);
-}
-
-inline Value PawnInfo::queenside_storm_value(Color c) const {
- return Value(qsStormValue[c]);
-}
-
inline Bitboard PawnInfo::passed_pawns(Color c) const {
return passedPawns[c];
}
return halfOpenFiles[c] & ~((1 << int(f+1)) - 1);
}
-inline Score PawnInfo::king_shelter(const Position& pos, Color c, Square ksq) {
- return kingSquares[c] == ksq ? kingShelters[c] : updateShelter(pos, c, ksq);
+/// PawnInfo::updateShelter() calculates and caches king shelter. It is called
+/// only when king square changes, about 20% of total king_shelter() calls.
+template<Color Us>
+Score PawnInfo::updateShelter(const Position& pos, Square ksq) {
+
+ const int Shift = (Us == WHITE ? 8 : -8);
+
+ Bitboard pawns;
+ int r, shelter = 0;
+
+ if (relative_rank(Us, ksq) <= RANK_4)
+ {
+ pawns = pos.pieces(PAWN, Us) & this_and_neighboring_files_bb(ksq);
+ r = square_rank(ksq) * 8;
+ for (int i = 1; i < 4; i++)
+ {
+ r += Shift;
+ shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (128 >> i);
+ }
+ }
+ kingSquares[Us] = ksq;
+ kingShelters[Us] = make_score(shelter, 0);
+ return kingShelters[Us];
+}
+
+template<Color Us>
+inline Score PawnInfo::king_shelter(const Position& pos, Square ksq) {
+ return kingSquares[Us] == ksq ? kingShelters[Us] : updateShelter<Us>(pos, ksq);
}
#endif // !defined(PAWNS_H_INCLUDED)