X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=db08b1c49e22179fee74b556741104ec3c5d1567;hp=55c5014a447c7f44c6614815bf49a100e4b4a87d;hb=dd8a07612843f32d4073135fc9e17b8814aa34a5;hpb=6125966da02eab5b726802286ef111c4adc63eab diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 55c5014a..db08b1c4 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -23,7 +23,6 @@ //// #include -#include #include "bitcount.h" #include "evaluate.h" @@ -39,7 +38,49 @@ namespace { - const int Sign[2] = { 1, -1 }; + // Struct EvalInfo contains various information computed and collected + // by the evaluation functions. + struct EvalInfo { + + // Pointer to pawn hash table entry + PawnInfo* pi; + + // updateKingTables[color] is set to true if we have enough material + // to trigger the opponent's king safety calculation. When is false we + // skip the time consuming update of the king attackers tables. + bool updateKingTables[2]; + + // attackedBy[color][piece type] is a bitboard representing all squares + // attacked by a given color and piece type, attackedBy[color][0] contains + // all squares attacked by the given color. + Bitboard attackedBy[2][8]; + + // kingZone[color] is the zone around the enemy king which is considered + // by the king safety evaluation. This consists of the squares directly + // adjacent to the king, and the three (or two, for a king on an edge file) + // squares two ranks in front of the king. For instance, if black's king + // is on g8, kingZone[WHITE] is a bitboard containing the squares f8, h8, + // f7, g7, h7, f6, g6 and h6. + Bitboard kingZone[2]; + + // kingAttackersCount[color] is the number of pieces of the given color + // which attack a square in the kingZone of the enemy king. + int kingAttackersCount[2]; + + // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the + // given color which attack a square in the kingZone of the enemy king. The + // weights of the individual piece types are given by the variables + // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and + // KnightAttackWeight in evaluate.cpp + int kingAttackersWeight[2]; + + // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares + // directly adjacent to the king of the given color. Pieces which attack + // more than one square are counted multiple times. For instance, if black's + // king is on g8 and there's a white knight on g5, this knight adds + // 2 to kingAdjacentZoneAttacksCount[BLACK]. + int kingAdjacentZoneAttacksCount[2]; + }; // Evaluation grain size, must be a power of 2 const int GrainSize = 8; @@ -61,8 +102,9 @@ namespace { S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0) }; - // Pieces mobility bonus in middle game and endgame, indexed by piece type - // and number of attacked squares not occupied by friendly pieces. + // MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and + // end game, indexed by piece type and number of attacked squares not occupied + // by friendly pieces. const Score MobilityBonus[][32] = { {}, {}, { S(-38,-33), S(-25,-23), S(-12,-13), S( 0, -3), S(12, 7), S(25, 17), // Knights @@ -81,8 +123,8 @@ namespace { S( 20, 35), S( 20, 35) } }; - // Outpost bonuses for knights and bishops, indexed by square (from white's - // point of view). + // OutpostBonus[PieceType][Square] contains outpost bonuses of knights and + // bishops, indexed by piece type and square (from white's point of view). const Value OutpostBonus[][64] = { { // A B C D E F G H @@ -105,9 +147,9 @@ namespace { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) } }; - // ThreatBonus[attacking][attacked] contains bonus according to which - // piece type attacks which one. - const Score ThreatBonus[8][8] = { + // ThreatBonus[attacking][attacked] contains threat bonuses according to + // which piece type attacks which one. + const Score ThreatBonus[][8] = { {}, {}, { S(0, 0), S( 7, 39), S( 0, 0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT { S(0, 0), S( 7, 39), S(24, 49), S( 0, 0), S(41,100), S(41,100) }, // BISHOP @@ -115,9 +157,9 @@ namespace { { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN }; - // ThreatedByPawnPenalty[] contains a penalty according to which piece - // type is attacked by an enemy pawn. - const Score ThreatedByPawnPenalty[8] = { + // ThreatedByPawnPenalty[PieceType] contains a penalty according to which + // piece type is attacked by an enemy pawn. + const Score ThreatedByPawnPenalty[] = { S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118) }; @@ -135,37 +177,38 @@ namespace { // right to castle. const Value TrappedRookPenalty = Value(180); - // The SpaceMask[color] contains the area of the board which is considered + // The SpaceMask[Color] contains the area of the board which is considered // by the space evaluation. In the middle game, each side is given a bonus // based on how many squares inside this area are safe and available for // friendly minor pieces. - const Bitboard SpaceMask[2] = { - (1ULL< - Value do_evaluate(const Position& pos, EvalInfo& ei); + Value do_evaluate(const Position& pos, Value margins[]); template - void init_attack_tables(const Position& pos, EvalInfo& ei); + void init_eval_info(const Position& pos, EvalInfo& ei); template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei); + Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility); template - void evaluate_king(const Position& pos, EvalInfo& ei); + Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]); template - void evaluate_threats(const Position& pos, EvalInfo& ei); + Score evaluate_threats(const Position& pos, EvalInfo& ei); template int evaluate_space(const Position& pos, EvalInfo& ei); template - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei); + Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei); - inline Score apply_weight(Score v, Score weight); + Score apply_weight(Score v, Score weight); Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]); Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight); void init_safety(); @@ -225,104 +269,92 @@ void prefetchPawn(Key key, int threadID) { PawnTable[threadID]->prefetch(key); } + /// evaluate() is the main evaluation function. It always computes two /// values, an endgame score and a middle game score, and interpolates /// between them based on the remaining material. -Value evaluate(const Position& pos, EvalInfo& ei) { +Value evaluate(const Position& pos, Value margins[]) { - return CpuHasPOPCNT ? do_evaluate(pos, ei) - : do_evaluate(pos, ei); + return CpuHasPOPCNT ? do_evaluate(pos, margins) + : do_evaluate(pos, margins); } namespace { template -Value do_evaluate(const Position& pos, EvalInfo& ei) { +Value do_evaluate(const Position& pos, Value margins[]) { + EvalInfo ei; ScaleFactor factor[2]; + Score mobilityWhite, mobilityBlack; assert(pos.is_ok()); assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS); assert(!pos.is_check()); - memset(&ei, 0, sizeof(EvalInfo)); + // Initialize value by reading the incrementally updated scores included + // in the position object (material + piece square tables). + Score bonus = pos.value(); - // Initialize by reading the incrementally updated scores included in the - // position object (material + piece square tables) - ei.value = pos.value(); + // margins[color] is the uncertainty estimation of position's evaluation + // and typically is used by the search for pruning decisions. + margins[WHITE] = margins[BLACK] = VALUE_ZERO; // Probe the material hash table - ei.mi = MaterialTable[pos.thread()]->get_material_info(pos); - ei.value += ei.mi->material_value(); + MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos); + bonus += mi->material_value(); // If we have a specialized evaluation function for the current material - // configuration, call it and return - if (ei.mi->specialized_eval_exists()) - return ei.mi->evaluate(pos); + // configuration, call it and return. + if (mi->specialized_eval_exists()) + return mi->evaluate(pos); // After get_material_info() call that modifies them - factor[WHITE] = ei.mi->scale_factor(pos, WHITE); - factor[BLACK] = ei.mi->scale_factor(pos, BLACK); + factor[WHITE] = mi->scale_factor(pos, WHITE); + factor[BLACK] = mi->scale_factor(pos, BLACK); // Probe the pawn hash table ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos); - ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); - - // Initialize attack bitboards with pawns evaluation - init_attack_tables(pos, ei); - init_attack_tables(pos, ei); + bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); - // Evaluate pieces - evaluate_pieces_of_color(pos, ei); - evaluate_pieces_of_color(pos, ei); + // Initialize attack and king safety bitboards + init_eval_info(pos, ei); + init_eval_info(pos, ei); - // Kings. Kings are evaluated after all other pieces for both sides, - // because we need complete attack information for all pieces when computing - // the king safety evaluation. - evaluate_king(pos, ei); - evaluate_king(pos, ei); + // Evaluate pieces and mobility + bonus += evaluate_pieces_of_color(pos, ei, mobilityWhite) + - evaluate_pieces_of_color(pos, ei, mobilityBlack); - // Evaluate tactical threats, we need full attack info including king - evaluate_threats(pos, ei); - evaluate_threats(pos, ei); + bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]); - // Evaluate passed pawns, we need full attack info including king - evaluate_passed_pawns(pos, ei); - evaluate_passed_pawns(pos, ei); + // Evaluate kings after all other pieces because we need complete attack + // information when computing the king safety evaluation. + bonus += evaluate_king(pos, ei, margins) + - evaluate_king(pos, ei, margins); - Phase phase = ei.mi->game_phase(); + // Evaluate tactical threats, we need full attack information including king + bonus += evaluate_threats(pos, ei) + - evaluate_threats(pos, ei); - // Middle-game specific evaluation terms - if (phase > PHASE_ENDGAME) - { - // Evaluate 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); - - else if ( square_file(pos.king_square(WHITE)) <= FILE_D - && square_file(pos.king_square(BLACK)) >= FILE_E) + // Evaluate passed pawns, we need full attack information including king + bonus += evaluate_passed_pawns(pos, ei) + - evaluate_passed_pawns(pos, ei); - ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0); + Phase phase = mi->game_phase(); - // Evaluate space for both sides - if (ei.mi->space_weight() > 0) - { - int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); - ei.value += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]); - } + // Evaluate space for both sides, only in middle-game. + if (phase > PHASE_ENDGAME && mi->space_weight() > 0) + { + int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); + bonus += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]); } - // Mobility - 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 if ( phase < PHASE_MIDGAME && pos.opposite_colored_bishops() - && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(ei.value) > VALUE_ZERO) - || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(ei.value) < VALUE_ZERO))) + && ( (factor[WHITE] == SCALE_FACTOR_NORMAL && eg_value(bonus) > VALUE_ZERO) + || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(bonus) < VALUE_ZERO))) { ScaleFactor sf; @@ -347,11 +379,13 @@ Value do_evaluate(const Position& pos, EvalInfo& ei) { } // Interpolate between the middle game and the endgame score - return Sign[pos.side_to_move()] * scale_by_game_phase(ei.value, phase, factor); + Value v = scale_by_game_phase(bonus, phase, factor); + return pos.side_to_move() == WHITE ? v : -v; } } // namespace + /// init_eval() initializes various tables used by the evaluation function void init_eval(int threads) { @@ -360,18 +394,19 @@ void init_eval(int threads) { for (int i = 0; i < MAX_THREADS; i++) { - if (i >= threads) - { - delete PawnTable[i]; - delete MaterialTable[i]; - PawnTable[i] = NULL; - MaterialTable[i] = NULL; - continue; - } - if (!PawnTable[i]) - PawnTable[i] = new PawnInfoTable(); - if (!MaterialTable[i]) - MaterialTable[i] = new MaterialInfoTable(); + if (i >= threads) + { + delete PawnTable[i]; + delete MaterialTable[i]; + PawnTable[i] = NULL; + MaterialTable[i] = NULL; + continue; + } + if (!PawnTable[i]) + PawnTable[i] = new PawnInfoTable(); + + if (!MaterialTable[i]) + MaterialTable[i] = new MaterialInfoTable(); } } @@ -380,13 +415,7 @@ void init_eval(int threads) { void quit_eval() { - for (int i = 0; i < MAX_THREADS; i++) - { - delete PawnTable[i]; - delete MaterialTable[i]; - PawnTable[i] = NULL; - MaterialTable[i] = NULL; - } + init_eval(0); } @@ -417,27 +446,31 @@ void read_weights(Color us) { namespace { - // init_attack_tables() initializes king bitboards for both sides adding - // pawn attacks. To be done before other evaluations. + // init_eval_info() initializes king bitboards for given color adding + // pawn attacks. To be done at the beginning of the evaluation. template - void init_attack_tables(const Position& pos, EvalInfo& ei) { + void init_eval_info(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(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(b) / 2; + ei.updateKingTables[Us] = pos.piece_count(Us, QUEEN) && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame; + if (ei.updateKingTables[Us]) + { + b &= ei.attackedBy[Us][PAWN]; + ei.kingAttackersCount[Us] = b ? count_1s_max_15(b) / 2 : EmptyBoardBB; + ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = EmptyBoardBB; + } } // evaluate_outposts() evaluates bishop and knight outposts squares template - void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { + Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -447,7 +480,7 @@ namespace { Value bonus = OutpostBonus[Piece == BISHOP][relative_square(Us, s)]; // Increase bonus if supported by pawn, especially if the opponent has - // no minor piece which can exchange the outpost piece + // no minor piece which can exchange the outpost piece. if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s)) { if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB @@ -456,23 +489,26 @@ namespace { else bonus += bonus / 2; } - ei.value += Sign[Us] * make_score(bonus, bonus); + return make_score(bonus, bonus); } // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color template - void evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) { + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard no_mob_area) { Bitboard b; Square s, ksq; int mob; File f; + Score bonus = SCORE_ZERO; const Color Them = (Us == WHITE ? BLACK : WHITE); const Square* ptr = pos.piece_list_begin(Us, Piece); + ei.attackedBy[Us][Piece] = EmptyBoardBB; + while ((s = *ptr++) != SQ_NONE) { // Find attacked squares, including x-ray attacks for bishops and rooks @@ -489,7 +525,7 @@ namespace { ei.attackedBy[Us][Piece] |= b; // King attacks - if (b & ei.kingZone[Us]) + if (ei.updateKingTables[Us] && (b & ei.kingZone[Us])) { ei.kingAttackersCount[Us]++; ei.kingAttackersWeight[Us] += KingAttackWeights[Piece]; @@ -502,23 +538,23 @@ namespace { mob = (Piece != QUEEN ? count_1s_max_15(b & no_mob_area) : count_1s(b & no_mob_area)); - ei.mobility += Sign[Us] * MobilityBonus[Piece][mob]; + mobility += 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. if (bit_is_set(ei.attackedBy[Them][PAWN], s)) - ei.value -= Sign[Us] * ThreatedByPawnPenalty[Piece]; + bonus -= ThreatedByPawnPenalty[Piece]; // Bishop and knight outposts squares if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us)) - evaluate_outposts(pos, ei, s); + bonus += evaluate_outposts(pos, ei, s); // 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) { - ei.value += Sign[Us] * (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); + bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); } // Special extra evaluation for rooks @@ -529,9 +565,9 @@ namespace { if (ei.pi->file_is_half_open(Us, f)) { if (ei.pi->file_is_half_open(Them, f)) - ei.value += Sign[Us] * RookOpenFileBonus; + bonus += RookOpenFileBonus; else - ei.value += Sign[Us] * RookHalfOpenFileBonus; + bonus += RookHalfOpenFileBonus; } // Penalize rooks which are trapped inside a king. Penalize more if @@ -547,8 +583,8 @@ namespace { { // Is there a half-open file between the king and the edge of the board? if (!ei.pi->has_open_file_to_right(Us, square_file(ksq))) - ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 - : (TrappedRookPenalty - mob * 16), 0); + bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + : (TrappedRookPenalty - mob * 16), 0); } else if ( square_file(ksq) <= FILE_D && square_file(s) < square_file(ksq) @@ -556,11 +592,12 @@ namespace { { // 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))) - ei.value -= Sign[Us] * make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 - : (TrappedRookPenalty - mob * 16), 0); + bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + : (TrappedRookPenalty - mob * 16), 0); } } } + return bonus; } @@ -568,7 +605,7 @@ namespace { // and the type of attacked one. template - void evaluate_threats(const Position& pos, EvalInfo& ei) { + Score evaluate_threats(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -580,11 +617,11 @@ namespace { & ~ei.attackedBy[Them][PAWN] & ei.attackedBy[Us][0]; if (!weakEnemies) - return; + return SCORE_ZERO; - // Add bonus according to type of attacked enemy pieces and to the + // Add bonus according to type of attacked enemy piece and to the // type of attacking piece, from knights to queens. Kings are not - // considered because are already special handled in king evaluation. + // considered because are already handled in king evaluation. for (PieceType pt1 = KNIGHT; pt1 < KING; pt1++) { b = ei.attackedBy[Us][pt1] & weakEnemies; @@ -593,7 +630,7 @@ namespace { if (b & pos.pieces(pt2)) bonus += ThreatBonus[pt1][pt2]; } - ei.value += Sign[Us] * bonus; + return bonus; } @@ -601,56 +638,54 @@ namespace { // pieces of a given color. template - void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) { + Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) { const Color Them = (Us == WHITE ? BLACK : WHITE); + Score bonus = mobility = SCORE_ZERO; + // 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); + bonus += evaluate_pieces(pos, ei, mobility, no_mob_area); + bonus += evaluate_pieces(pos, ei, mobility, no_mob_area); + bonus += evaluate_pieces(pos, ei, mobility, no_mob_area); + bonus += evaluate_pieces(pos, ei, mobility, 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]; + return bonus; } // evaluate_king<>() assigns bonuses and penalties to a king of a given color template - void evaluate_king(const Position& pos, EvalInfo& ei) { + Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) { const Color Them = (Us == WHITE ? BLACK : WHITE); Bitboard undefended, b, b1, b2, safe; - bool sente; int attackUnits; const Square ksq = pos.king_square(Us); // King shelter - ei.value += Sign[Us] * ei.pi->king_shelter(pos, Us, ksq); + Score bonus = ei.pi->king_shelter(pos, ksq); // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. - if ( pos.piece_count(Them, QUEEN) >= 1 - && ei.kingAttackersCount[Them] >= 2 - && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame + if ( ei.updateKingTables[Them] + && ei.kingAttackersCount[Them] >= 2 && ei.kingAdjacentZoneAttacksCount[Them]) { - // Is it the attackers turn to move? - sente = (Them == pos.side_to_move()); - // Find the attacked squares around the king which has no defenders // apart from the king itself - 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)); + undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING]; + undefended &= ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] + | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] + | ei.attackedBy[Us][QUEEN]); // Initialize the 'attackUnits' variable, which is used later on as an // index to the KingDangerTable[] array. The initial value is based on @@ -660,43 +695,63 @@ namespace { attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15(undefended)) + InitKingDanger[relative_square(Us, ksq)] - - mg_value(ei.pi->king_shelter(pos, Us, ksq)) / 32; + - mg_value(ei.pi->king_shelter(pos, ksq)) / 32; // Analyse enemy's safe queen contact checks. First find undefended // squares around the king attacked by enemy queen... - b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them); + b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces_of_color(Them); if (b) { // ...then remove squares not supported by another enemy piece - b &= ( ei.attacked_by(Them, PAWN) | ei.attacked_by(Them, KNIGHT) - | ei.attacked_by(Them, BISHOP) | ei.attacked_by(Them, ROOK)); + b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] + | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]); if (b) - attackUnits += QueenContactCheckBonus * count_1s_max_15(b) * (sente ? 2 : 1); + attackUnits += QueenContactCheckBonus + * count_1s_max_15(b) + * (Them == pos.side_to_move() ? 2 : 1); + } + + // Analyse enemy's safe rook contact checks. First find undefended + // squares around the king attacked by enemy rooks... + b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces_of_color(Them); + + // Consider only squares where the enemy rook gives check + b &= RookPseudoAttacks[ksq]; + + if (b) + { + // ...then remove squares not supported by another enemy piece + b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] + | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]); + if (b) + attackUnits += RookContactCheckBonus + * count_1s_max_15(b) + * (Them == pos.side_to_move() ? 2 : 1); } // Analyse enemy's safe distance checks for sliders and knights - safe = ~(pos.pieces_of_color(Them) | ei.attacked_by(Us)); + safe = ~(pos.pieces_of_color(Them) | ei.attackedBy[Us][0]); b1 = pos.attacks_from(ksq) & safe; b2 = pos.attacks_from(ksq) & safe; // Enemy queen safe checks - b = (b1 | b2) & ei.attacked_by(Them, QUEEN); + b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; if (b) attackUnits += QueenCheckBonus * count_1s_max_15(b); // Enemy rooks safe checks - b = b1 & ei.attacked_by(Them, ROOK); + b = b1 & ei.attackedBy[Them][ROOK]; if (b) attackUnits += RookCheckBonus * count_1s_max_15(b); // Enemy bishops safe checks - b = b2 & ei.attacked_by(Them, BISHOP); + b = b2 & ei.attackedBy[Them][BISHOP]; if (b) attackUnits += BishopCheckBonus * count_1s_max_15(b); // Enemy knights safe checks - b = pos.attacks_from(ksq) & ei.attacked_by(Them, KNIGHT) & safe; + b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe; if (b) attackUnits += KnightCheckBonus * count_1s_max_15(b); @@ -704,53 +759,57 @@ namespace { attackUnits = Min(99, Max(0, attackUnits)); // Finally, extract the king danger score from the KingDangerTable[] - // array and subtract the score from evaluation. Set also ei.kingDanger[] + // array and subtract the score from evaluation. Set also margins[] // value that will be used for pruning because this value can sometimes // be very big, and so capturing a single attacking piece can therefore // result in a score change far bigger than the value of the captured piece. - ei.value -= Sign[Us] * KingDangerTable[Us][attackUnits]; - ei.kingDanger[Us] = mg_value(KingDangerTable[Us][attackUnits]); + bonus -= KingDangerTable[Us][attackUnits]; + margins[Us] += mg_value(KingDangerTable[Us][attackUnits]); } + return bonus; } // evaluate_passed_pawns<>() evaluates the passed pawns of the given color template - void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { + Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); + Score bonus = SCORE_ZERO; Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns; Bitboard b = ei.pi->passed_pawns(Us); - while (b) - { + if (!b) + return SCORE_ZERO; + + do { Square s = pop_1st_bit(&b); assert(pos.pawn_is_passed(Us, s)); int r = int(relative_rank(Us, s) - RANK_2); - int tr = r * (r - 1); + int rr = r * (r - 1); // Base bonus based on rank - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); + Value mbonus = Value(20 * rr); + Value ebonus = Value(10 * (rr + r + 1)); - if (tr) + if (rr) { Square blockSq = s + pawn_push(Us); // Adjust bonus based on kings proximity - 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); + ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr); + ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr); + ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * rr); // If the pawn is free to advance, increase bonus if (pos.square_is_empty(blockSq)) { squaresToQueen = squares_in_front_of(Us, s); - defendedSquares = squaresToQueen & ei.attacked_by(Us); + defendedSquares = squaresToQueen & ei.attackedBy[Us][0]; // 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 @@ -759,25 +818,25 @@ namespace { && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) unsafeSquares = squaresToQueen; else - unsafeSquares = squaresToQueen & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); + unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces_of_color(Them)); // If there aren't enemy attacks or pieces along the path to queen give // huge bonus. Even bigger if we protect the pawn's path. if (!unsafeSquares) - ebonus += Value(tr * (squaresToQueen == defendedSquares ? 17 : 15)); + ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15)); else // OK, there are enemy attacks or pieces (but not pawns). Are those // squares which are attacked by the enemy also attacked by us ? // If yes, big bonus (but smaller than when there are no enemy attacks), // if no, somewhat smaller bonus. - ebonus += Value(tr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8)); + ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8)); // At last, add a small bonus when there are no *friendly* pieces // in the pawn's path. if (!(squaresToQueen & pos.pieces_of_color(Us))) - ebonus += Value(tr); + ebonus += Value(rr); } - } // tr != 0 + } // rr != 0 // Increase the bonus if the passed pawn is supported by a friendly pawn // on the same rank and a bit smaller if it's on the previous rank. @@ -800,11 +859,12 @@ namespace { else if (pos.pieces(ROOK, QUEEN, Them)) ebonus -= ebonus / 4; } + bonus += make_score(mbonus, ebonus); - // 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 (b); - } // while + // Add the scores to the middle game and endgame eval + return apply_weight(bonus, Weights[PassedPawns]); } @@ -813,19 +873,19 @@ namespace { // available for minor pieces on the central four files on ranks 2--4. Safe // squares one, two or three squares behind a friendly pawn are counted // twice. Finally, the space bonus is scaled by a weight taken from the - // material hash table. + // material hash table. The aim is to improve play on game opening. template int evaluate_space(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); // Find the safe squares for our pieces inside the area defined by - // SpaceMask[us]. A square is unsafe if it is attacked by an enemy + // SpaceMask[]. A square is unsafe if it is attacked by an enemy // pawn, or if it is undefended and attacked by an enemy piece. Bitboard safe = SpaceMask[Us] & ~pos.pieces(PAWN, Us) - & ~ei.attacked_by(Them, PAWN) - & (ei.attacked_by(Us) | ~ei.attacked_by(Them)); + & ~ei.attackedBy[Them][PAWN] + & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]); // Find all squares which are at most three squares behind some friendly pawn Bitboard behind = pos.pieces(PAWN, Us); @@ -839,7 +899,8 @@ namespace { // apply_weight() applies an evaluation weight to a value trying to prevent overflow inline Score apply_weight(Score v, Score w) { - return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, (int(eg_value(v)) * eg_value(w)) / 0x100); + return make_score((int(mg_value(v)) * mg_value(w)) / 0x100, + (int(eg_value(v)) * eg_value(w)) / 0x100); } @@ -873,6 +934,7 @@ namespace { return apply_weight(make_score(mg, eg), internalWeight); } + // init_safety() initizes the king safety evaluation, based on UCI // parameters. It is called from read_weights().