#undef S
+ // Threats weights indexed by sente (side to move has a bigger weight)
+ const int ConcurrentThreatsWeight[2] = { 3, 15 };
+ const int ThreatsWeight[2] = { 249, 267 };
+
// Bonus for unstoppable passed pawns
const Value UnstoppablePawnValue = Value(0x500);
template<bool HasPopCnt>
Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID);
+ template<Color Us, bool HasPopCnt>
+ void init_attack_tables(const Position& pos, EvalInfo& ei);
+
template<Color Us, bool HasPopCnt>
void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei);
template<bool HasPopCnt>
Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
- Bitboard b;
ScaleFactor factor[2];
assert(pos.is_ok());
ei.pi = PawnTable[threadID]->get_pawn_info(pos);
ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
- // Initialize king attack bitboards and king attack zones for both sides
- ei.attackedBy[WHITE][KING] = pos.attacks_from<KING>(pos.king_square(WHITE));
- ei.attackedBy[BLACK][KING] = pos.attacks_from<KING>(pos.king_square(BLACK));
- ei.kingZone[WHITE] = ei.attackedBy[BLACK][KING] | (ei.attackedBy[BLACK][KING] >> 8);
- ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8);
-
- // Initialize pawn attack bitboards for both sides
- ei.attackedBy[WHITE][PAWN] = ei.pi->pawn_attacks(WHITE);
- b = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING];
- if (b)
- ei.kingAttackersCount[WHITE] = count_1s_max_15<HasPopCnt>(b)/2;
-
- ei.attackedBy[BLACK][PAWN] = ei.pi->pawn_attacks(BLACK);
- b = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING];
- if (b)
- ei.kingAttackersCount[BLACK] = count_1s_max_15<HasPopCnt>(b)/2;
+ // Initialize attack bitboards with pawns evaluation
+ init_attack_tables<WHITE, HasPopCnt>(pos, ei);
+ init_attack_tables<BLACK, HasPopCnt>(pos, ei);
// Evaluate pieces
evaluate_pieces_of_color<WHITE, HasPopCnt>(pos, ei);
// Middle-game specific evaluation terms
if (phase > PHASE_ENDGAME)
{
- // Pawn storms in positions with opposite castling
- if ( square_file(pos.king_square(WHITE)) >= FILE_E
- && square_file(pos.king_square(BLACK)) <= FILE_D)
+ // Pawn storms in positions with opposite castling
+ if ( square_file(pos.king_square(WHITE)) >= FILE_E
+ && square_file(pos.king_square(BLACK)) <= FILE_D)
- ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
+ ei.value += make_score(ei.pi->queenside_storm_value(WHITE) - ei.pi->kingside_storm_value(BLACK), 0);
- else if ( square_file(pos.king_square(WHITE)) <= FILE_D
- && square_file(pos.king_square(BLACK)) >= FILE_E)
+ else if ( square_file(pos.king_square(WHITE)) <= FILE_D
+ && square_file(pos.king_square(BLACK)) >= FILE_E)
- ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
+ ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0);
- // Evaluate space for both sides
- if (ei.mi->space_weight() > 0)
- {
- evaluate_space<WHITE, HasPopCnt>(pos, ei);
- evaluate_space<BLACK, HasPopCnt>(pos, ei);
- }
+ // Evaluate space for both sides
+ if (ei.mi->space_weight() > 0)
+ {
+ evaluate_space<WHITE, HasPopCnt>(pos, ei);
+ evaluate_space<BLACK, HasPopCnt>(pos, ei);
+ }
}
// Mobility
namespace {
+ // init_king_tables() initializes king bitboards for both sides adding
+ // pawn attacks. To be done before other evaluations.
+
+ template<Color Us, bool HasPopCnt>
+ void init_attack_tables(const Position& pos, EvalInfo& ei) {
+
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from<KING>(pos.king_square(Them));
+ ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
+ ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
+ b &= ei.attackedBy[Us][PAWN];
+ if (b)
+ ei.kingAttackersCount[Us] = count_1s_max_15<HasPopCnt>(b) / 2;
+ }
+
+
// evaluate_outposts() evaluates bishop and knight outposts squares
template<PieceType Piece, Color Us>
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard b;
+ Value mg, eg;
+ int sente, threatCount = 0;
Score bonus = make_score(0, 0);
// Enemy pieces not defended by a pawn and under our attack
if (b)
for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
if (b & pos.pieces(pt2))
+ {
bonus += ThreatBonus[pt1][pt2];
+ threatCount++;
+ }
}
- ei.value += Sign[Us] * bonus;
+
+ sente = (Us == pos.side_to_move());
+
+ // Non linear threat evaluation. Increase threats score according to the
+ // number of concurrent threats and to the side to move.
+ mg = (mg_value(bonus) + mg_value(bonus) * ConcurrentThreatsWeight[sente] * threatCount / 256) * ThreatsWeight[sente] / 256;
+ eg = (eg_value(bonus) + eg_value(bonus) * ConcurrentThreatsWeight[sente] * threatCount / 256) * ThreatsWeight[sente] / 256;
+
+ ei.value += Sign[Us] * make_score(mg, eg);
}
squaresToQueen = squares_in_front_of(Us, s);
defendedSquares = squaresToQueen & ei.attacked_by(Us);
- // There are no enemy pawns in the pawn's path
- assert(!(squaresToQueen & pos.pieces(PAWN, Them)));
-
// If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen. Otherwise consider only
// the squares in the pawn's path attacked or occupied by the enemy.
Square s = pop_1st_bit(&b);
Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8));
int d = square_distance(s, queeningSquare)
+ - (relative_rank(c, s) == RANK_2) // Double pawn push
- square_distance(pos.king_square(opposite_color(c)), queeningSquare)
+ int(c != pos.side_to_move());
projects / stockfish / blobdiff