X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=4575958c0bdd6cad71975417e32b954b0477faa9;hp=add8540807d595cee96dc3184c12c28e6924a1f4;hb=569bc75eb860f2b644e3797c465205579c7d3ed7;hpb=ef6fca98a0b70b82ba701e6969a80cd9daf78705 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index add85408..4575958c 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2009 Marco Costalba + Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -46,9 +46,11 @@ namespace { const int GrainSize = 8; // Evaluation weights, initialized from UCI options - Score WeightMobility, WeightPawnStructure; - Score WeightPassedPawns, WeightSpace; - Score WeightKingSafety[2]; + enum { Mobility, PawnStructure, PassedPawns, Space, KingSafetyUs, KingSafetyThem }; + Score Weights[6]; + + typedef Value V; + #define S(mg, eg) make_score(mg, eg) // Internal evaluation weights. These are applied on top of the evaluation // weights read from UCI parameters. The purpose is to be able to change @@ -56,22 +58,13 @@ namespace { // parameters at 100, which looks prettier. // // Values modified by Joona Kiiski - const Score WeightMobilityInternal = make_score(248, 271); - const Score WeightPawnStructureInternal = make_score(233, 201); - const Score WeightPassedPawnsInternal = make_score(252, 259); - const Score WeightSpaceInternal = make_score( 46, 0); - const Score WeightKingSafetyInternal = make_score(247, 0); - const Score WeightKingOppSafetyInternal = make_score(259, 0); - - // Mobility and outposts bonus modified by Joona Kiiski - // - // Visually better to define tables constants - typedef Value V; - #define S(mg, eg) make_score(mg, eg) + const Score WeightsInternal[] = { + S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0) + }; // Knight mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly piecess. - const Score KnightMobilityBonus[] = { + const Score KnightMobilityBonus[16] = { S(-38,-33), S(-25,-23), S(-12,-13), S( 0,-3), S( 12, 7), S( 25, 17), S( 31, 22), S(38, 27), S(38, 27) }; @@ -79,7 +72,7 @@ namespace { // Bishop mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly pieces. X-ray attacks through // queens are also included. - const Score BishopMobilityBonus[] = { + const Score BishopMobilityBonus[16] = { S(-25,-30), S(-11,-16), S( 3, -2), S(17, 12), S( 31, 26), S( 45, 40), S(57, 52), S(65, 60), S( 71, 65), S( 74, 69), S(76, 71), S(78, 73), @@ -89,7 +82,7 @@ namespace { // Rook mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly pieces. X-ray attacks through // queens and rooks are also included. - const Score RookMobilityBonus[] = { + const Score RookMobilityBonus[16] = { S(-20,-36), S(-14,-19), S(-8, -3), S(-2, 13), S( 4, 29), S( 10, 46), S(14, 62), S(19, 79), S( 23, 95), S( 26,106), S(27,111), S(28,114), @@ -98,7 +91,7 @@ namespace { // Queen mobility bonus in middle game and endgame, indexed by the number // of attacked squares not occupied by friendly pieces. - const Score QueenMobilityBonus[] = { + const Score QueenMobilityBonus[32] = { S(-10,-18), S(-8,-13), S(-6, -7), S(-3, -2), S(-1, 3), S( 1, 8), S( 3, 13), S( 5, 19), S( 8, 23), S(10, 27), S(12, 32), S(15, 34), S( 16, 35), S(17, 35), S(18, 35), S(20, 35), S(20, 35), S(20, 35), @@ -108,7 +101,8 @@ namespace { }; // Pointers table to access mobility tables through piece type - const Score* MobilityBonus[] = { 0, 0, KnightMobilityBonus, BishopMobilityBonus, RookMobilityBonus, QueenMobilityBonus }; + const Score* MobilityBonus[8] = { 0, 0, KnightMobilityBonus, BishopMobilityBonus, + RookMobilityBonus, QueenMobilityBonus, 0, 0 }; // Outpost bonuses for knights and bishops, indexed by square (from white's // point of view). @@ -136,6 +130,30 @@ namespace { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8 }; + // ThreatBonus[][] contains bonus according to which piece type + // attacks which one. + #define Z S(0, 0) + + const Score ThreatBonus[8][8] = { + { Z, Z, Z, Z, Z, Z, Z, Z }, // not used + { Z, S(18,37), Z, S(37,47), S(55,97), S(55,97), Z, Z }, // KNIGHT attacks + { Z, S(18,37), S(37,47), Z, S(55,97), S(55,97), Z, Z }, // BISHOP attacks + { Z, S( 9,27), S(27,47), S(27,47), Z, S(37,47), Z, Z }, // ROOK attacks + { Z, S(27,37), S(27,37), S(27,37), S(27,37), Z, Z, Z }, // QUEEN attacks + { Z, Z, Z, Z, Z, Z, Z, Z }, // not used + { Z, Z, Z, Z, Z, Z, Z, Z }, // not used + { Z, Z, Z, Z, Z, Z, Z, Z } // not used + }; + + // ThreatedByPawnPenalty[] contains a penalty according to which piece + // type is attacked by an enemy pawn. + const Score ThreatedByPawnPenalty[8] = { + Z, Z, S(56, 70), S(56, 70), S(76, 99), S(86, 118), Z, Z + }; + + #undef Z + #undef S + // Bonus for unstoppable passed pawns const Value UnstoppablePawnValue = Value(0x500); @@ -198,39 +216,19 @@ namespace { const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight }; - // Bonuses for safe checks, initialized from UCI options - int QueenContactCheckBonus, DiscoveredCheckBonus; - int QueenCheckBonus, RookCheckBonus, BishopCheckBonus, KnightCheckBonus; + // Bonuses for safe checks + const int QueenContactCheckBonus = 3; + const int DiscoveredCheckBonus = 3; + const int QueenCheckBonus = 2; + const int RookCheckBonus = 1; + const int BishopCheckBonus = 1; + const int KnightCheckBonus = 1; // Scan for queen contact mates? const bool QueenContactMates = true; - // Bonus for having a mate threat, initialized from UCI options - int MateThreatBonus; - - // ThreatBonus[][] contains bonus according to which piece type - // attacks which one. - #define Z make_score(0, 0) - - const Score ThreatBonus[8][8] = { - { Z, Z, Z, Z, Z, Z, Z, Z }, // not used - { Z, S(18,37), Z, S(37,47), S(55,97), S(55,97), Z, Z }, // KNIGHT attacks - { Z, S(18,37), S(37,47), Z, S(55,97), S(55,97), Z, Z }, // BISHOP attacks - { Z, S( 9,27), S(27,47), S(27,47), Z, S(37,47), Z, Z }, // ROOK attacks - { Z, S(27,37), S(27,37), S(27,37), S(27,37), Z, Z, Z }, // QUEEN attacks - { Z, Z, Z, Z, Z, Z, Z, Z }, // not used - { Z, Z, Z, Z, Z, Z, Z, Z }, // not used - { Z, Z, Z, Z, Z, Z, Z, Z } // not used - }; - - // ThreatedByPawnPenalty[] contains a penalty according to which piece - // type is attacked by an enemy pawn. - const Score ThreatedByPawnPenalty[8] = { - Z, Z, S(56, 70), S(56, 70), S(76, 99), S(86, 118), Z, Z - }; - - #undef Z - #undef S + // Bonus for having a mate threat + const int MateThreatBonus = 3; // InitKingDanger[] contains bonuses based on the position of the defending // king. @@ -245,13 +243,13 @@ namespace { 15, 15, 15, 15, 15, 15, 15, 15 }; - // SafetyTable[] contains the actual king safety scores. It is initialized - // in init_safety(). - Value SafetyTable[100]; + // SafetyTable[color][] contains the actual king safety weighted scores + Score SafetyTable[2][128]; - // Pawn and material hash tables, indexed by the current thread id - PawnInfoTable* PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0}; - MaterialInfoTable* MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0}; + // Pawn and material hash tables, indexed by the current thread id. + // Note that they will be initialized at 0 being global variables. + MaterialInfoTable* MaterialTable[MAX_THREADS]; + PawnInfoTable* PawnTable[MAX_THREADS]; // Sizes of pawn and material hash tables const int PawnTableSize = 16384; @@ -273,7 +271,10 @@ namespace { template void evaluate_space(const Position& pos, EvalInfo& ei); + template void evaluate_passed_pawns(const Position& pos, EvalInfo& ei); + + void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei); void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo& ei); void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei); inline Score apply_weight(Score v, Score weight); @@ -301,8 +302,11 @@ namespace { template Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { + Bitboard b; + ScaleFactor factor[2]; + assert(pos.is_ok()); - assert(threadID >= 0 && threadID < THREAD_MAX); + assert(threadID >= 0 && threadID < MAX_THREADS); assert(!pos.is_check()); memset(&ei, 0, sizeof(EvalInfo)); @@ -321,13 +325,12 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { return ei.mi->evaluate(pos); // After get_material_info() call that modifies them - ScaleFactor factor[2]; factor[WHITE] = ei.mi->scale_factor(pos, WHITE); factor[BLACK] = ei.mi->scale_factor(pos, BLACK); // Probe the pawn hash table ei.pi = PawnTable[threadID]->get_pawn_info(pos); - ei.value += apply_weight(ei.pi->value(), WeightPawnStructure); + 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(pos.king_square(WHITE)); @@ -337,14 +340,14 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { // Initialize pawn attack bitboards for both sides ei.attackedBy[WHITE][PAWN] = ei.pi->pawn_attacks(WHITE); - ei.attackedBy[BLACK][PAWN] = ei.pi->pawn_attacks(BLACK); - Bitboard b1 = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING]; - Bitboard b2 = ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING]; - if (b1) - ei.kingAttackersCount[WHITE] = count_1s_max_15(b1)/2; + b = ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING]; + if (b) + ei.kingAttackersCount[WHITE] = count_1s_max_15(b)/2; - if (b2) - ei.kingAttackersCount[BLACK] = count_1s_max_15(b2)/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(b)/2; // Evaluate pieces evaluate_pieces_of_color(pos, ei); @@ -356,23 +359,24 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { evaluate_king(pos, ei); evaluate_king(pos, ei); - // Evaluate tactical threats, we need full attack info + // Evaluate tactical threats, we need full attack info including king evaluate_threats(pos, ei); evaluate_threats(pos, ei); - // Evaluate passed pawns. We evaluate passed pawns for both sides at once, - // because we need to know which side promotes first in positions where - // both sides have an unstoppable passed pawn. To be called after all attacks - // are computed, included king. - if (ei.pi->passed_pawns()) - evaluate_passed_pawns(pos, ei); + // Evaluate passed pawns, we need full attack info including king + evaluate_passed_pawns(pos, ei); + evaluate_passed_pawns(pos, ei); + + // If one side has only a king, check whether exsists any unstoppable passed pawn + if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK)) + evaluate_unstoppable_pawns(pos, ei); - Phase phase = pos.game_phase(); + Phase phase = ei.mi->game_phase(); // Middle-game specific evaluation terms if (phase > PHASE_ENDGAME) { - // Pawn storms in positions with opposite castling. + // Pawn storms in positions with opposite castling if ( square_file(pos.king_square(WHITE)) >= FILE_E && square_file(pos.king_square(BLACK)) <= FILE_D) @@ -392,7 +396,7 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { } // Mobility - ei.value += apply_weight(ei.mobility, WeightMobility); + ei.value += apply_weight(ei.mobility, Weights[Mobility]); // If we don't already have an unusual scale factor, check for opposite // colored bishop endgames, and use a lower scale for those @@ -433,31 +437,13 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { } // namespace -/// quick_evaluate() does a very approximate evaluation of the current position. -/// It currently considers only material and piece square table scores. Perhaps -/// we should add scores from the pawn and material hash tables? - -Value quick_evaluate(const Position &pos) { - - assert(pos.is_ok()); - - static const - ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL}; - - Phase ph = pos.game_phase(); - Color stm = pos.side_to_move(); - - return Sign[stm] * scale_by_game_phase(pos.value(), ph, sf); -} - - /// init_eval() initializes various tables used by the evaluation function void init_eval(int threads) { - assert(threads <= THREAD_MAX); + assert(threads <= MAX_THREADS); - for (int i = 0; i < THREAD_MAX; i++) + for (int i = 0; i < MAX_THREADS; i++) { if (i >= threads) { @@ -479,7 +465,7 @@ void init_eval(int threads) { void quit_eval() { - for (int i = 0; i < THREAD_MAX; i++) + for (int i = 0; i < MAX_THREADS; i++) { delete PawnTable[i]; delete MaterialTable[i]; @@ -493,57 +479,29 @@ void quit_eval() { void read_weights(Color us) { - Color them = opposite_color(us); + // King safety is asymmetrical. Our king safety is controled by "Cowardice" + // UCI parameter, instead the opponent one by "Aggressiveness". + const int kingSafetyUs = (us == WHITE ? KingSafetyUs : KingSafetyThem); + const int kingSafetyThem = (us == WHITE ? KingSafetyThem : KingSafetyUs); - WeightMobility = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightMobilityInternal); - WeightPawnStructure = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightPawnStructureInternal); - WeightPassedPawns = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightPassedPawnsInternal); - WeightSpace = weight_option("Space", "Space", WeightSpaceInternal); - WeightKingSafety[us] = weight_option("Cowardice", "Cowardice", WeightKingSafetyInternal); - WeightKingSafety[them] = weight_option("Aggressiveness", "Aggressiveness", WeightKingOppSafetyInternal); + Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]); + Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]); + Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]); + Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]); + Weights[kingSafetyUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingSafetyUs]); + Weights[kingSafetyThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingSafetyThem]); // If running in analysis mode, make sure we use symmetrical king safety. We do this - // by replacing both WeightKingSafety[us] and WeightKingSafety[them] by their average. + // by replacing both Weights[kingSafetyUs] and Weights[kingSafetyThem] by their average. if (get_option_value_bool("UCI_AnalyseMode")) - { - WeightKingSafety[us] = (WeightKingSafety[us] + WeightKingSafety[them]) / 2; - WeightKingSafety[them] = WeightKingSafety[us]; - } + Weights[kingSafetyUs] = Weights[kingSafetyThem] = (Weights[kingSafetyUs] + Weights[kingSafetyThem]) / 2; + init_safety(); } namespace { - // evaluate_mobility() computes mobility and attacks for every piece - - template - int evaluate_mobility(Bitboard b, Bitboard mob_area, EvalInfo& ei) { - - const Color Them = (Us == WHITE ? BLACK : WHITE); - - // Update attack info - ei.attackedBy[Us][Piece] |= b; - - // King attacks - if (b & ei.kingZone[Us]) - { - ei.kingAttackersCount[Us]++; - ei.kingAttackersWeight[Us] += AttackWeight[Piece]; - Bitboard bb = (b & ei.attackedBy[Them][KING]); - if (bb) - ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); - } - - // Mobility - int mob = (Piece != QUEEN ? count_1s_max_15(b & mob_area) - : count_1s(b & mob_area)); - - ei.mobility += Sign[Us] * MobilityBonus[Piece][mob]; - return mob; - } - - // evaluate_outposts() evaluates bishop and knight outposts squares template @@ -557,7 +515,7 @@ namespace { // Increase bonus if supported by pawn, especially if the opponent has // no minor piece which can exchange the outpost piece - if (bonus && (pos.attacks_from(s, Them) & pos.pieces(PAWN, Us))) + if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s)) { if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB) @@ -572,7 +530,7 @@ namespace { // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color template - void evaluate_pieces(const Position& pos, EvalInfo& ei) { + void evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) { Bitboard b; Square s, ksq; @@ -582,11 +540,9 @@ namespace { const Color Them = (Us == WHITE ? BLACK : WHITE); const Square* ptr = pos.piece_list_begin(Us, Piece); - // Do not include in mobility squares protected by enemy pawns or occupied by our pieces - const Bitboard mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); - while ((s = *ptr++) != SQ_NONE) { + // Find attacked squares, including x-ray attacks for bishops and rooks if (Piece == KNIGHT || Piece == QUEEN) b = pos.attacks_from(s); else if (Piece == BISHOP) @@ -596,8 +552,24 @@ namespace { else assert(false); - // Attacks and mobility - mob = evaluate_mobility(b, mob_area, ei); + // Update attack info + ei.attackedBy[Us][Piece] |= b; + + // King attacks + if (b & ei.kingZone[Us]) + { + ei.kingAttackersCount[Us]++; + ei.kingAttackersWeight[Us] += AttackWeight[Piece]; + Bitboard bb = (b & ei.attackedBy[Them][KING]); + if (bb) + ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); + } + + // Mobility + mob = (Piece != QUEEN ? count_1s_max_15(b & no_mob_area) + : count_1s(b & no_mob_area)); + + ei.mobility += Sign[Us] * MobilityBonus[Piece][mob]; // Decrease score if we are attacked by an enemy pawn. Remaining part // of threat evaluation must be done later when we have full attack info. @@ -619,14 +591,12 @@ namespace { evaluate_trapped_bishop_a1h1(pos, s, Us, ei); } - if (Piece == ROOK || Piece == QUEEN) + // Queen or rook on 7th rank + if ( (Piece == ROOK || Piece == QUEEN) + && relative_rank(Us, s) == RANK_7 + && relative_rank(Us, pos.king_square(Them)) == RANK_8) { - // Queen or rook on 7th rank - if ( relative_rank(Us, s) == RANK_7 - && relative_rank(Us, pos.king_square(Them)) == RANK_8) - { - ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); - } + ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); } // Special extra evaluation for rooks @@ -659,8 +629,8 @@ namespace { : (TrappedRookPenalty - mob * 16), 0); } else if ( square_file(ksq) <= FILE_D - && square_file(s) < square_file(ksq) - && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) + && square_file(s) < square_file(ksq) + && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) { // Is there a half-open file between the king and the edge of the board? if (!ei.pi->has_open_file_to_left(Us, square_file(ksq))) @@ -711,15 +681,20 @@ namespace { template void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) { - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); - evaluate_pieces(pos, ei); + const Color Them = (Us == WHITE ? BLACK : WHITE); + + // Do not include in mobility squares protected by enemy pawns or occupied by our pieces + const Bitboard no_mob_area = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); + + evaluate_pieces(pos, ei, no_mob_area); + evaluate_pieces(pos, ei, no_mob_area); + evaluate_pieces(pos, ei, no_mob_area); + evaluate_pieces(pos, ei, no_mob_area); - // Sum up all attacked squares - ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] - | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] - | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING]; + // Sum up all attacked squares + ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] + | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] + | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING]; } @@ -729,8 +704,12 @@ namespace { void evaluate_king(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); + + Bitboard undefended, attackedByOthers, escapeSquares, occ, b, b2, safe; + Square from, to; + bool sente; + int attackUnits, count, shelter = 0; const Square s = pos.king_square(Us); - int shelter = 0; // King shelter if (relative_rank(Us, s) <= RANK_4) @@ -747,77 +726,80 @@ namespace { && ei.kingAdjacentZoneAttacksCount[Them]) { // Is it the attackers turn to move? - bool sente = (Them == pos.side_to_move()); + sente = (Them == pos.side_to_move()); // Find the attacked squares around the king which has no defenders // 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); - - Bitboard occ = pos.occupied_squares(), b, b2; + undefended = ei.attacked_by(Them) & ei.attacked_by(Us, KING); + undefended &= ~( 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)); // Initialize the 'attackUnits' variable, which is used later on as an - // index to the SafetyTable[] array. The initial value is based on the + // index to the SafetyTable[] array. The initial value is based on the // number and types of the attacking pieces, the number of attacked and // 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 >> 5); + attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) + + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15(undefended)) + + InitKingDanger[relative_square(Us, s)] + - (shelter >> 5); // Analyse safe queen contact checks b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.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, ROOK); + attackedByOthers = ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT) + | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK); b &= attackedByOthers; + + // Squares attacked by the queen and supported by another enemy piece and + // not defended by other pieces but our king. 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); - - // Is there a mate threat? - if (QueenContactMates && !pos.is_check()) - { - Bitboard escapeSquares = - pos.attacks_from(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers; - - while (b) + // The bitboard b now contains the squares available for safe queen + // contact checks. + count = count_1s_max_15(b); + attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1); + + // Is there a mate threat? + if (QueenContactMates && !pos.is_check()) { - Square from, to = pop_1st_bit(&b); - if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[s]))) + escapeSquares = pos.attacks_from(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers; + occ = pos.occupied_squares(); + while (b) { - // We have a mate, unless the queen is pinned or there - // is an X-ray attack through the queen. - for (int i = 0; i < pos.piece_count(Them, QUEEN); i++) - { - from = pos.piece_list(Them, QUEEN, i); - if ( bit_is_set(pos.attacks_from(from), to) - && !bit_is_set(pos.pinned_pieces(Them), from) - && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us)) - && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us))) + to = pop_1st_bit(&b); - ei.mateThreat[Them] = make_move(from, to); + // Do we have escape squares from queen contact check attack ? + if (!(escapeSquares & ~queen_attacks_bb(to, occ & ClearMaskBB[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 < pos.piece_count(Them, QUEEN); i++) + { + from = pos.piece_list(Them, QUEEN, i); + if ( bit_is_set(pos.attacks_from(from), to) + && !bit_is_set(pos.pinned_pieces(Them), from) + && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(ROOK, QUEEN, Us)) + && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & pos.pieces(BISHOP, QUEEN, Us))) + + // Set the mate threat move + ei.mateThreat[Them] = make_move(from, to); + } } } } - } } } // Analyse safe distance checks + safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us)); + if (QueenCheckBonus > 0 || RookCheckBonus > 0) { - b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); + b = pos.attacks_from(s) & safe; // Queen checks b2 = b & ei.attacked_by(Them, QUEEN); @@ -831,7 +813,7 @@ namespace { } if (QueenCheckBonus > 0 || BishopCheckBonus > 0) { - b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); + b = pos.attacks_from(s) & safe; // Queen checks b2 = b & ei.attacked_by(Them, QUEEN); @@ -845,7 +827,7 @@ namespace { } if (KnightCheckBonus > 0) { - b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); + b = pos.attacks_from(s) & safe; // Knight checks b2 = b & ei.attacked_by(Them, KNIGHT); @@ -857,12 +839,12 @@ namespace { // adding pawns later). if (DiscoveredCheckBonus) { - b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN); - if (b) - attackUnits += DiscoveredCheckBonus * count_1s_max_15(b) * (sente ? 2 : 1); + b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN); + 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 + // 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. @@ -870,40 +852,29 @@ namespace { 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; + // out of bounds errors. + attackUnits = Min(99, Max(0, attackUnits)); // Finally, extract the king safety score from the SafetyTable[] array. - // Add the score to the evaluation, and also to ei.futilityMargin. The - // reason for adding the king safety score to the futility margin is - // that the king safety scores can sometimes be very big, and that + // Subtract the score from evaluation, and set ei.futilityMargin[]. + // The reason for storing the king safety score to futility margin + // is that the king safety scores can sometimes be very big, and that // capturing a single attacking piece can therefore result in a score // change far bigger than the value of the captured piece. - Score v = apply_weight(make_score(SafetyTable[attackUnits], 0), WeightKingSafety[Us]); - - ei.value -= Sign[Us] * v; - - if (Us == pos.side_to_move()) - ei.futilityMargin += mg_value(v); + ei.value -= Sign[Us] * SafetyTable[Us][attackUnits]; + ei.futilityMargin[Us] = mg_value(SafetyTable[Us][attackUnits]); } } - // evaluate_passed_pawns() evaluates the passed pawns of the given color + // evaluate_passed_pawns<>() evaluates the passed pawns of the given color template - void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) { + void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); - Bitboard b2, b3, b4; - Square ourKingSq = pos.king_square(Us); - Square theirKingSq = pos.king_square(Them); - Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, Us); + Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(Us); while (b) { @@ -924,23 +895,23 @@ namespace { { Square blockSq = s + pawn_push(Us); - ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr); - ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(Us)) * 1 * tr); - ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr); + ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * tr); + ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * 1 * tr); + ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * tr); // If the pawn is free to advance, increase bonus if (pos.square_is_empty(blockSq)) { // There are no enemy pawns in the pawn's path - b2 = squares_in_front_of(Us, s); + Bitboard b2 = squares_in_front_of(Us, s); assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB); // Squares attacked by us - b4 = b2 & ei.attacked_by(Us); + Bitboard b4 = b2 & ei.attacked_by(Us); // Squares attacked or occupied by enemy pieces - b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); + Bitboard b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); // If there is an enemy rook or queen attacking the pawn from behind, // add all X-ray attacks by the rook or queen. @@ -968,38 +939,12 @@ namespace { } // tr != 0 // If the pawn is supported by a friendly pawn, increase bonus - b2 = pos.pieces(PAWN, Us) & neighboring_files_bb(s); - if (b2 & rank_bb(s)) + Bitboard b1 = pos.pieces(PAWN, Us) & neighboring_files_bb(s); + if (b1 & rank_bb(s)) ebonus += Value(r * 20); - else if (pos.attacks_from(s, Them) & b2) + else if (pos.attacks_from(s, Them) & b1) ebonus += Value(r * 12); - // If the other side has only a king, check whether the pawn is - // unstoppable - if (pos.non_pawn_material(Them) == Value(0)) - { - Square qsq; - int d; - - qsq = relative_square(Us, make_square(square_file(s), RANK_8)); - d = square_distance(s, qsq) - - square_distance(theirKingSq, qsq) - + (Us != pos.side_to_move()); - - if (d < 0) - { - int mtg = RANK_8 - relative_rank(Us, s); - int blockerCount = count_1s_max_15(squares_in_front_of(Us,s) & pos.occupied_squares()); - mtg += blockerCount; - d += blockerCount; - if (d < 0 && (!movesToGo[Us] || movesToGo[Us] > mtg)) - { - movesToGo[Us] = mtg; - pawnToGo[Us] = s; - } - } - } - // Rook pawns are a special case: They are sometimes worse, and // sometimes better than other passed pawns. It is difficult to find // good rules for determining whether they are good or bad. For now, @@ -1015,23 +960,50 @@ namespace { ebonus -= ebonus / 4; } - // Add the scores for this pawn to the middle game and endgame eval. - ei.value += Sign[Us] * apply_weight(make_score(mbonus, ebonus), WeightPassedPawns); + // Add the scores for this pawn to the middle game and endgame eval + ei.value += Sign[Us] * apply_weight(make_score(mbonus, ebonus), Weights[PassedPawns]); } // while } - // evaluate_passed_pawns() evaluates the passed pawns for both sides + // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { + void evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) { int movesToGo[2] = {0, 0}; Square pawnToGo[2] = {SQ_NONE, SQ_NONE}; - // Evaluate pawns for each color - evaluate_passed_pawns_of_color(pos, movesToGo, pawnToGo, ei); - evaluate_passed_pawns_of_color(pos, movesToGo, pawnToGo, ei); + for (Color c = WHITE; c <= BLACK; c++) + { + // Skip evaluation if other side has non-pawn pieces + if (pos.non_pawn_material(opposite_color(c))) + continue; + + Bitboard b = ei.pi->passed_pawns() & pos.pieces_of_color(c); + + while (b) + { + Square s = pop_1st_bit(&b); + Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8)); + int d = square_distance(s, queeningSquare) + - square_distance(pos.king_square(opposite_color(c)), queeningSquare) + + int(c != pos.side_to_move()); + + if (d < 0) + { + int mtg = RANK_8 - relative_rank(c, s); + int blockerCount = count_1s_max_15(squares_in_front_of(c, s) & pos.occupied_squares()); + mtg += blockerCount; + d += blockerCount; + if (d < 0 && (!movesToGo[c] || movesToGo[c] > mtg)) + { + movesToGo[c] = mtg; + pawnToGo[c] = s; + } + } + } + } // Neither side has an unstoppable passed pawn? if (!(movesToGo[WHITE] | movesToGo[BLACK])) @@ -1176,7 +1148,7 @@ namespace { int space = count_1s_max_15(safeSquares) + count_1s_max_15(behindFriendlyPawns & safeSquares); - ei.value += Sign[Us] * apply_weight(make_score(space * ei.mi->space_weight(), 0), WeightSpace); + ei.value += Sign[Us] * apply_weight(make_score(space * ei.mi->space_weight(), 0), Weights[Space]); } @@ -1223,43 +1195,37 @@ namespace { } // init_safety() initizes the king safety evaluation, based on UCI - // parameters. It is called from read_weights(). + // parameters. It is called from read_weights(). void init_safety() { - QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus"); - QueenCheckBonus = get_option_value_int("Queen Check Bonus"); - RookCheckBonus = get_option_value_int("Rook Check Bonus"); - BishopCheckBonus = get_option_value_int("Bishop Check Bonus"); - KnightCheckBonus = get_option_value_int("Knight Check Bonus"); - DiscoveredCheckBonus = get_option_value_int("Discovered Check Bonus"); - MateThreatBonus = get_option_value_int("Mate Threat Bonus"); - - int maxSlope = get_option_value_int("King Safety Max Slope"); - int peak = get_option_value_int("King Safety Max Value") * 256 / 100; - double a = get_option_value_int("King Safety Coefficient") / 100.0; - double b = get_option_value_int("King Safety X Intercept"); - bool quad = (get_option_value_string("King Safety Curve") == "Quadratic"); - bool linear = (get_option_value_string("King Safety Curve") == "Linear"); + int maxSlope = 30; + int peak = 0x500; + double a = 0.4; + double b = 0.0; + Value t[100]; + // First setup the base table for (int i = 0; i < 100; i++) { if (i < b) - SafetyTable[i] = Value(0); - else if (quad) - SafetyTable[i] = Value((int)(a * (i - b) * (i - b))); - else if (linear) - SafetyTable[i] = Value((int)(100 * a * (i - b))); + t[i] = Value(0); + else + t[i] = Value((int)(a * (i - b) * (i - b))); } - for (int i = 0; i < 100; i++) + for (int i = 1; i < 100; i++) { - if (SafetyTable[i+1] - SafetyTable[i] > maxSlope) - for (int j = i + 1; j < 100; j++) - SafetyTable[j] = SafetyTable[j-1] + Value(maxSlope); + if (t[i] - t[i - 1] > maxSlope) + t[i] = t[i - 1] + Value(maxSlope); - if (SafetyTable[i] > Value(peak)) - SafetyTable[i] = Value(peak); + if (t[i] > Value(peak)) + t[i] = Value(peak); } + + // Then apply the weights and get the final SafetyTable[] array + for (Color c = WHITE; c <= BLACK; c++) + for (int i = 0; i < 100; i++) + SafetyTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingSafetyUs + c]); } }