namespace Pawns {
-/// Pawns::Entry contains various information about a pawn structure. Currently,
-/// it only includes a middlegame and endgame 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 probe function)
-/// returns a pointer to an Entry 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.
struct Entry {
Score pawns_value() const { return value; }
Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
- Bitboard candidate_pawns(Color c) const { return candidatePawns[c]; }
- int pawns_on_same_color_squares(Color c, Square s) const { return pawnsOnSquares[c][!!(DarkSquares & s)]; }
- int semiopen(Color c, File f) const { return semiopenFiles[c] & (1 << int(f)); }
- int semiopen_on_side(Color c, File f, bool left) const {
- return semiopenFiles[c] & (left ? ((1 << int(f)) - 1) : ~((1 << int(f+1)) - 1));
+ int semiopen_file(Color c, File f) const {
+ return semiopenFiles[c] & (1 << f);
+ }
+
+ int semiopen_side(Color c, File f, bool leftSide) const {
+ return semiopenFiles[c] & (leftSide ? (1 << f) - 1 : ~((1 << (f + 1)) - 1));
+ }
+
+ int pawn_span(Color c) const {
+ return pawnSpan[c];
+ }
+
+ int pawns_on_same_color_squares(Color c, Square s) const {
+ return pawnsOnSquares[c][!!(DarkSquares & s)];
}
template<Color Us>
Score king_safety(const Position& pos, Square ksq) {
-
- return kingSquares[Us] == ksq && castlingRights[Us] == pos.can_castle(Us)
- ? kingSafety[Us] : update_safety<Us>(pos, ksq);
+ return kingSquares[Us] == ksq && castlingRights[Us] == pos.can_castle(Us)
+ ? kingSafety[Us] : (kingSafety[Us] = do_king_safety<Us>(pos, ksq));
}
template<Color Us>
- Score update_safety(const Position& pos, Square ksq);
+ Score do_king_safety(const Position& pos, Square ksq);
template<Color Us>
Value shelter_storm(const Position& pos, Square ksq);
Key key;
+ Score value;
Bitboard passedPawns[COLOR_NB];
- Bitboard candidatePawns[COLOR_NB];
Bitboard pawnAttacks[COLOR_NB];
Square kingSquares[COLOR_NB];
- int minKPdistance[COLOR_NB];
+ Score kingSafety[COLOR_NB];
+ int minKingPawnDistance[COLOR_NB];
int castlingRights[COLOR_NB];
- Score value;
int semiopenFiles[COLOR_NB];
- Score kingSafety[COLOR_NB];
- int pawnsOnSquares[COLOR_NB][COLOR_NB];
+ int pawnSpan[COLOR_NB];
+ int pawnsOnSquares[COLOR_NB][COLOR_NB]; // [color][light/dark squares]
};
typedef HashTable<Entry, 16384> Table;
void init();
Entry* probe(const Position& pos, Table& entries);
-}
+} // namespace Pawns
#endif // #ifndef PAWNS_H_INCLUDED