From: Marco Costalba Date: Thu, 25 Sep 2008 14:43:37 +0000 (+0200) Subject: Space inflate evaluate_king() X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=b00abed181edc96e6945b8e23ac49244477f49ae Space inflate evaluate_king() This is the most complex piece of software so far. Signed-off-by: Marco Costalba --- diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 3f95f0d3..864af221 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -697,6 +697,10 @@ namespace { } } + inline Bitboard shiftRowsDown(const Bitboard& b, int num) { + + return b >> (num << 3); + } // evaluate_king() assigns bonuses and penalties to a king of a given // color on a given square. @@ -705,32 +709,37 @@ namespace { int shelter = 0, sign = Sign[us]; - // King shelter. - if(relative_rank(us, s) <= RANK_4) { - Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s); - Rank r = square_rank(s); - for(int i = 0; i < 3; i++) - shelter += count_1s_8bit(pawns >> ((r+(i+1)*sign) * 8)) * (64>>i); - ei.mgValue += sign * Value(shelter); + // King shelter + if (relative_rank(us, s) <= RANK_4) + { + Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s); + Rank r = square_rank(s); + for (int i = 1; i < 4; i++) + shelter += count_1s_8bit(shiftRowsDown(pawns, r+i*sign)) * (128>>i); + + ei.mgValue += sign * Value(shelter); } // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. Color them = opposite_color(us); - if(p.queen_count(them) >= 1 && ei.kingAttackersCount[them] >= 2 - && p.non_pawn_material(them) >= QueenValueMidgame + RookValueMidgame - && ei.kingAdjacentZoneAttacksCount[them]) { + if ( p.queen_count(them) >= 1 + && ei.kingAttackersCount[them] >= 2 + && p.non_pawn_material(them) >= QueenValueMidgame + RookValueMidgame + && ei.kingAdjacentZoneAttacksCount[them]) + { // Is it the attackers turn to move? bool sente = (them == p.side_to_move()); // Find the attacked squares around the king which has no defenders - // apart from the king itself: + // apart from the king itself Bitboard undefended = - ei.attacked_by(them) & ~ei.attacked_by(us, PAWN) - & ~ei.attacked_by(us, KNIGHT) & ~ei.attacked_by(us, BISHOP) - & ~ei.attacked_by(us, ROOK) & ~ei.attacked_by(us, QUEEN) - & ei.attacked_by(us, KING); + ei.attacked_by(them) & ~ei.attacked_by(us, PAWN) + & ~ei.attacked_by(us, KNIGHT) & ~ei.attacked_by(us, BISHOP) + & ~ei.attacked_by(us, ROOK) & ~ei.attacked_by(us, QUEEN) + & ei.attacked_by(us, KING); + Bitboard occ = p.occupied_squares(), b, b2; // Initialize the 'attackUnits' variable, which is used later on as an @@ -739,113 +748,134 @@ namespace { // undefended squares around the king, the square of the king, and the // quality of the pawn shelter. int attackUnits = - Min((ei.kingAttackersCount[them] * ei.kingAttackersWeight[them]) / 2, 25) - + (ei.kingAdjacentZoneAttacksCount[them] + count_1s_max_15(undefended)) * 3 - + InitKingDanger[relative_square(us, s)] - shelter / 32; + Min((ei.kingAttackersCount[them] * ei.kingAttackersWeight[them]) / 2, 25) + + (ei.kingAdjacentZoneAttacksCount[them] + count_1s_max_15(undefended)) * 3 + + InitKingDanger[relative_square(us, s)] - shelter / 32; - // Analyse safe queen contact checks: + // Analyse safe queen contact checks b = undefended & ei.attacked_by(them, QUEEN) & ~p.pieces_of_color(them); - if(b) { + if (b) + { Bitboard attackedByOthers = - ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT) - | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, ROOK); + ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT) + | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, ROOK); + b &= attackedByOthers; - if(b) { + if (b) + { // The bitboard b now contains the squares available for safe queen // contact checks. int count = count_1s_max_15(b); - attackUnits += QueenContactCheckBonus * count * (sente? 2 : 1); + attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1); // Is there a mate threat? - if(QueenContactMates && !p.is_check()) { + if (QueenContactMates && !p.is_check()) + { Bitboard escapeSquares = - p.king_attacks(s) & ~p.pieces_of_color(us) & ~attackedByOthers; - while(b) { - Square from, to = pop_1st_bit(&b); - if(!(escapeSquares - & ~queen_attacks_bb(to, occ & clear_mask_bb(s)))) { - // We have a mate, unless the queen is pinned or there - // is an X-ray attack through the queen. - for(int i = 0; i < p.queen_count(them); i++) { - from = p.queen_list(them, i); - if(bit_is_set(p.queen_attacks(from), to) - && !bit_is_set(p.pinned_pieces(them), from) - && !(rook_attacks_bb(to, occ & clear_mask_bb(from)) - & p.rooks_and_queens(us)) - && !(rook_attacks_bb(to, occ & clear_mask_bb(from)) - & p.rooks_and_queens(us))) - ei.mateThreat[them] = make_move(from, to); + p.king_attacks(s) & ~p.pieces_of_color(us) & ~attackedByOthers; + + while (b) + { + Square from, to = pop_1st_bit(&b); + if (!(escapeSquares & ~queen_attacks_bb(to, occ & clear_mask_bb(s)))) + { + // We have a mate, unless the queen is pinned or there + // is an X-ray attack through the queen. + for (int i = 0; i < p.queen_count(them); i++) + { + from = p.queen_list(them, i); + if ( bit_is_set(p.queen_attacks(from), to) + && !bit_is_set(p.pinned_pieces(them), from) + && !(rook_attacks_bb(to, occ & clear_mask_bb(from)) & p.rooks_and_queens(us)) + && !(rook_attacks_bb(to, occ & clear_mask_bb(from)) & p.rooks_and_queens(us))) + + ei.mateThreat[them] = make_move(from, to); + } } - } } } } } - // Analyse safe rook contact checks: - if(RookContactCheckBonus) { - b = undefended & ei.attacked_by(them, ROOK) & ~p.pieces_of_color(them); - if(b) { - Bitboard attackedByOthers = - ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT) - | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, QUEEN); - b &= attackedByOthers; - if(b) { - int count = count_1s_max_15(b); - attackUnits += (RookContactCheckBonus * count * (sente? 2 : 1)); + if (RookContactCheckBonus) + { + b = undefended & ei.attacked_by(them, ROOK) & ~p.pieces_of_color(them); + if (b) + { + Bitboard attackedByOthers = + ei.attacked_by(them, PAWN) | ei.attacked_by(them, KNIGHT) + | ei.attacked_by(them, BISHOP) | ei.attacked_by(them, QUEEN); + + b &= attackedByOthers; + if (b) + { + int count = count_1s_max_15(b); + attackUnits += (RookContactCheckBonus * count * (sente? 2 : 1)); + } } - } } - // Analyse safe distance checks: - if(QueenCheckBonus > 0 || RookCheckBonus > 0) { - b = p.rook_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); + if (QueenCheckBonus > 0 || RookCheckBonus > 0) + { + b = p.rook_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); - // Queen checks - b2 = b & ei.attacked_by(them, QUEEN); - if(b2) attackUnits += QueenCheckBonus * count_1s_max_15(b2); + // Queen checks + b2 = b & ei.attacked_by(them, QUEEN); + if( b2) + attackUnits += QueenCheckBonus * count_1s_max_15(b2); - // Rook checks - b2 = b & ei.attacked_by(them, ROOK); - if(b2) attackUnits += RookCheckBonus * count_1s_max_15(b2); + // Rook checks + b2 = b & ei.attacked_by(them, ROOK); + if (b2) + attackUnits += RookCheckBonus * count_1s_max_15(b2); } - if(QueenCheckBonus > 0 || BishopCheckBonus > 0) { - b = p.bishop_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); - // Queen checks - b2 = b & ei.attacked_by(them, QUEEN); - if(b2) attackUnits += QueenCheckBonus * count_1s_max_15(b2); - - // Bishop checks - b2 = b & ei.attacked_by(them, BISHOP); - if(b2) attackUnits += BishopCheckBonus * count_1s_max_15(b2); + if (QueenCheckBonus > 0 || BishopCheckBonus > 0) + { + b = p.bishop_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); + + // Queen checks + b2 = b & ei.attacked_by(them, QUEEN); + if (b2) + attackUnits += QueenCheckBonus * count_1s_max_15(b2); + + // Bishop checks + b2 = b & ei.attacked_by(them, BISHOP); + if (b2) + attackUnits += BishopCheckBonus * count_1s_max_15(b2); } - if(KnightCheckBonus > 0) { - b = p.knight_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); - // Knight checks - b2 = b & ei.attacked_by(them, KNIGHT); - if(b2) attackUnits += KnightCheckBonus * count_1s_max_15(b2); + if (KnightCheckBonus > 0) + { + b = p.knight_attacks(s) & ~p.pieces_of_color(them) & ~ei.attacked_by(us); + + // Knight checks + b2 = b & ei.attacked_by(them, KNIGHT); + if (b2) + attackUnits += KnightCheckBonus * count_1s_max_15(b2); } // Analyse discovered checks (only for non-pawns right now, consider // adding pawns later). - if(DiscoveredCheckBonus) { + if (DiscoveredCheckBonus) + { b = p.discovered_check_candidates(them) & ~p.pawns(); - if(b) - attackUnits += - DiscoveredCheckBonus * count_1s_max_15(b) * (sente? 2 : 1); + if (b) + attackUnits += DiscoveredCheckBonus * count_1s_max_15(b) * (sente? 2 : 1); } // Has a mate threat been found? We don't do anything here if the // side with the mating move is the side to move, because in that // case the mating side will get a huge bonus at the end of the main // evaluation function instead. - if(ei.mateThreat[them] != MOVE_NONE) - attackUnits += MateThreatBonus; + if (ei.mateThreat[them] != MOVE_NONE) + attackUnits += MateThreatBonus; // Ensure that attackUnits is between 0 and 99, in order to avoid array // out of bounds errors: - if(attackUnits < 0) attackUnits = 0; - if(attackUnits >= 100) attackUnits = 99; + if (attackUnits < 0) + attackUnits = 0; + + if (attackUnits >= 100) + attackUnits = 99; // Finally, extract the king safety score from the SafetyTable[] array. // Add the score to the evaluation, and also to ei.futilityMargin. The @@ -854,9 +884,11 @@ namespace { // capturing a single attacking piece can therefore result in a score // change far bigger than the value of the captured piece. Value v = apply_weight(SafetyTable[attackUnits], WeightKingSafety[us]); + ei.mgValue -= sign * v; - if(us == p.side_to_move()) - ei.futilityMargin += v; + + if (us == p.side_to_move()) + ei.futilityMargin += v; } }