X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=9007e9c78a1d73e642e89e2ee07c90487fbc7f30;hp=afb3e5930c708a9e4890f4c18b4f71260cd5d0b1;hb=2655f93c322c69c9ad85bd4be69d545c05e9260a;hpb=d56345c9aed35afcd0fddf1599f7a1b02e3a5499 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index afb3e593..9007e9c7 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -207,8 +207,8 @@ namespace { ((1ULL << SQ_A8) | (1ULL << SQ_H8)) }; - // The SpaceMask[color] contains area of the board which is consdered by - // the space evaluation. In the middle game, each side is given a bonus + // 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] = { @@ -274,22 +274,18 @@ namespace { void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei); template - void evaluate_king(const Position& p, EvalInfo &ei); + void evaluate_king(const Position& pos, EvalInfo& ei); - void evaluate_passed_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); - template - void evaluate_space(const Position &p, Color us, EvalInfo &ei); + template + void evaluate_space(const Position& pos, EvalInfo& ei); + + void evaluate_passed_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 Value apply_weight(Value v, int w); Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]); - - int compute_weight(int uciWeight, int internalWeight); int weight_option(const std::string& opt, int weight); void init_safety(); - } @@ -348,8 +344,8 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { ei.kingZone[BLACK] = ei.attackedBy[WHITE][KING] | (ei.attackedBy[WHITE][KING] << 8); // Initialize pawn attack bitboards for both sides - ei.attackedBy[WHITE][PAWN] = ((pos.pieces(PAWN, WHITE) << 9) & ~FileABB) | ((pos.pieces(PAWN, WHITE) << 7) & ~FileHBB); - ei.attackedBy[BLACK][PAWN] = ((pos.pieces(PAWN, BLACK) >> 7) & ~FileABB) | ((pos.pieces(PAWN, BLACK) >> 9) & ~FileHBB); + 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) @@ -368,7 +364,7 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { evaluate_king(pos, ei); evaluate_king(pos, ei); - // Evaluate passed pawns. We evaluate passed pawns for both sides at once, + // 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. if (ei.pi->passed_pawns()) @@ -395,8 +391,8 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { // Evaluate space for both sides if (ei.mi->space_weight() > 0) { - evaluate_space(pos, WHITE, ei); - evaluate_space(pos, BLACK, ei); + evaluate_space(pos, ei); + evaluate_space(pos, ei); } } @@ -433,8 +429,7 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { factor[BLACK] = sf; } - // Interpolate between the middle game and the endgame score, and - // return + // Interpolate between the middle game and the endgame score Color stm = pos.side_to_move(); Value v = Sign[stm] * scale_by_game_phase(ei.mgValue, ei.egValue, phase, factor); @@ -445,7 +440,7 @@ 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 +/// 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) { @@ -464,7 +459,7 @@ Value quick_evaluate(const Position &pos) { } -/// init_eval() initializes various tables used by the evaluation function. +/// init_eval() initializes various tables used by the evaluation function void init_eval(int threads) { @@ -488,7 +483,7 @@ void init_eval(int threads) { } -/// quit_eval() releases heap-allocated memory at program termination. +/// quit_eval() releases heap-allocated memory at program termination void quit_eval() { @@ -502,32 +497,29 @@ void quit_eval() { } -/// read_weights() reads evaluation weights from the corresponding UCI -/// parameters. +/// read_weights() reads evaluation weights from the corresponding UCI parameters void read_weights(Color us) { + Color them = opposite_color(us); + WeightMobilityMidgame = weight_option("Mobility (Middle Game)", WeightMobilityMidgameInternal); WeightMobilityEndgame = weight_option("Mobility (Endgame)", WeightMobilityEndgameInternal); WeightPawnStructureMidgame = weight_option("Pawn Structure (Middle Game)", WeightPawnStructureMidgameInternal); WeightPawnStructureEndgame = weight_option("Pawn Structure (Endgame)", WeightPawnStructureEndgameInternal); WeightPassedPawnsMidgame = weight_option("Passed Pawns (Middle Game)", WeightPassedPawnsMidgameInternal); WeightPassedPawnsEndgame = weight_option("Passed Pawns (Endgame)", WeightPassedPawnsEndgameInternal); + WeightSpace = weight_option("Space", WeightSpaceInternal); + WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal); + WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal); - Color them = opposite_color(us); - - WeightKingSafety[us] = weight_option("Cowardice", WeightKingSafetyInternal); - WeightKingSafety[them] = weight_option("Aggressiveness", WeightKingOppSafetyInternal); - // 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. - if (get_option_value_bool("UCI_AnalyseMode")) { + // 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. + if (get_option_value_bool("UCI_AnalyseMode")) + { WeightKingSafety[us] = (WeightKingSafety[us] + WeightKingSafety[them]) / 2; WeightKingSafety[them] = WeightKingSafety[us]; } - - WeightSpace = weight_option("Space", WeightSpaceInternal); - init_safety(); } @@ -537,12 +529,13 @@ namespace { // evaluate_mobility() computes mobility and attacks for every piece template - int evaluate_mobility(const Position& p, const Bitboard& b, EvalInfo& ei) { + int evaluate_mobility(const Position& pos, Bitboard b, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight }; static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus }; static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus }; + static const int lastIndex[] = { 0, 0, 8, 15, 15, 31 }; // Update attack info ei.attackedBy[Us][Piece] |= b; @@ -557,12 +550,22 @@ namespace { ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); } - // Remove squares protected by enemy pawns - Bitboard bb = (b & ~ei.attackedBy[Them][PAWN]); + // Remove squares protected by enemy pawns or occupied by our pieces + b &= ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); + + // The squares occupied by enemy pieces (not defended by pawns) will be + // counted two times instead of one. The shift (almost) guarantees that + // intersection of the shifted value with b is zero so that after or-ing + // the count of 1s bits is increased by the number of affected squares. + b |= Us == WHITE ? ((b & pos.pieces_of_color(Them)) >> 1) + : ((b & pos.pieces_of_color(Them)) << 1); // Mobility - int mob = (Piece != QUEEN ? count_1s_max_15(bb & ~p.pieces_of_color(Us)) - : count_1s(bb & ~p.pieces_of_color(Us))); + int mob = (Piece != QUEEN ? count_1s_max_15(b) + : count_1s(b)); + + if (mob > lastIndex[Piece]) + mob = lastIndex[Piece]; ei.mgMobility += Sign[Us] * MgBonus[Piece][mob]; ei.egMobility += Sign[Us] * EgBonus[Piece][mob]; @@ -573,7 +576,7 @@ namespace { // evaluate_outposts() evaluates bishop and knight outposts squares template - void evaluate_outposts(const Position& p, EvalInfo& ei, Square s) { + void evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -583,10 +586,10 @@ namespace { // Increase bonus if supported by pawn, especially if the opponent has // no minor piece which can exchange the outpost piece - if (bonus && (p.attacks_from(s, Them) & p.pieces(PAWN, Us))) + if (bonus && (pos.attacks_from(s, Them) & pos.pieces(PAWN, Us))) { - if ( p.pieces(KNIGHT, Them) == EmptyBoardBB - && (SquaresByColorBB[square_color(s)] & p.pieces(BISHOP, Them)) == EmptyBoardBB) + if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB + && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB) bonus += bonus + bonus / 2; else bonus += bonus / 2; @@ -596,8 +599,7 @@ namespace { } - // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given - // color. + // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color template void evaluate_pieces(const Position& pos, EvalInfo& ei) { @@ -698,8 +700,9 @@ namespace { } } - // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the pieces of a given - // color. + + // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the + // pieces of a given color. template void evaluate_pieces_of_color(const Position& pos, EvalInfo& ei) { @@ -715,31 +718,32 @@ namespace { | ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING]; } - // evaluate_king<>() assigns bonuses and penalties to a king of a given color. + + // evaluate_king<>() assigns bonuses and penalties to a king of a given color template - void evaluate_king(const Position& p, EvalInfo& ei) { + void evaluate_king(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square s = p.king_square(Us); + const Square s = pos.king_square(Us); int shelter = 0; // King shelter if (relative_rank(Us, s) <= RANK_4) { - shelter = ei.pi->get_king_shelter(p, Us, s); + shelter = ei.pi->get_king_shelter(pos, Us, s); ei.mgValue += Sign[Us] * Value(shelter); } // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. - if ( p.piece_count(Them, QUEEN) >= 1 + if ( pos.piece_count(Them, QUEEN) >= 1 && ei.kingAttackersCount[Them] >= 2 - && p.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame + && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame && ei.kingAdjacentZoneAttacksCount[Them]) { // Is it the attackers turn to move? - bool sente = (Them == p.side_to_move()); + bool sente = (Them == pos.side_to_move()); // Find the attacked squares around the king which has no defenders // apart from the king itself @@ -749,7 +753,7 @@ namespace { & ~ei.attacked_by(Us, ROOK) & ~ei.attacked_by(Us, QUEEN) & ei.attacked_by(Us, KING); - Bitboard occ = p.occupied_squares(), b, b2; + Bitboard occ = pos.occupied_squares(), b, b2; // Initialize the 'attackUnits' variable, which is used later on as an // index to the SafetyTable[] array. The initial value is based on the @@ -762,7 +766,7 @@ namespace { + InitKingDanger[relative_square(Us, s)] - (shelter >> 5); // Analyse safe queen contact checks - b = undefended & ei.attacked_by(Them, QUEEN) & ~p.pieces_of_color(Them); + b = undefended & ei.attacked_by(Them, QUEEN) & ~pos.pieces_of_color(Them); if (b) { Bitboard attackedByOthers = @@ -778,10 +782,10 @@ namespace { attackUnits += QueenContactCheckBonus * count * (sente ? 2 : 1); // Is there a mate threat? - if (QueenContactMates && !p.is_check()) + if (QueenContactMates && !pos.is_check()) { Bitboard escapeSquares = - p.attacks_from(s) & ~p.pieces_of_color(Us) & ~attackedByOthers; + pos.attacks_from(s) & ~pos.pieces_of_color(Us) & ~attackedByOthers; while (b) { @@ -790,13 +794,13 @@ namespace { { // 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.piece_count(Them, QUEEN); i++) + for (int i = 0; i < pos.piece_count(Them, QUEEN); i++) { - from = p.piece_list(Them, QUEEN, i); - if ( bit_is_set(p.attacks_from(from), to) - && !bit_is_set(p.pinned_pieces(Them), from) - && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.pieces(ROOK, QUEEN, Us)) - && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & p.pieces(BISHOP, QUEEN, Us))) + 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))) ei.mateThreat[Them] = make_move(from, to); } @@ -809,11 +813,11 @@ namespace { // Analyse safe distance checks if (QueenCheckBonus > 0 || RookCheckBonus > 0) { - b = p.attacks_from(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us); + b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); // Queen checks b2 = b & ei.attacked_by(Them, QUEEN); - if( b2) + if (b2) attackUnits += QueenCheckBonus * count_1s_max_15(b2); // Rook checks @@ -823,7 +827,7 @@ namespace { } if (QueenCheckBonus > 0 || BishopCheckBonus > 0) { - b = p.attacks_from(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us); + b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); // Queen checks b2 = b & ei.attacked_by(Them, QUEEN); @@ -837,7 +841,7 @@ namespace { } if (KnightCheckBonus > 0) { - b = p.attacks_from(s) & ~p.pieces_of_color(Them) & ~ei.attacked_by(Us); + b = pos.attacks_from(s) & ~pos.pieces_of_color(Them) & ~ei.attacked_by(Us); // Knight checks b2 = b & ei.attacked_by(Them, KNIGHT); @@ -849,7 +853,7 @@ namespace { // adding pawns later). if (DiscoveredCheckBonus) { - b = p.discovered_check_candidates(Them) & ~p.pieces(PAWN); + b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN); if (b) attackUnits += DiscoveredCheckBonus * count_1s_max_15(b) * (sente ? 2 : 1); } @@ -879,144 +883,155 @@ namespace { ei.mgValue -= Sign[Us] * v; - if (Us == p.side_to_move()) + if (Us == pos.side_to_move()) ei.futilityMargin += v; } } - // evaluate_passed_pawns() evaluates the passed pawns for both sides. + // evaluate_passed_pawns() evaluates the passed pawns of the given color + + template + void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], EvalInfo& ei) { - void evaluate_passed_pawns(const Position &pos, EvalInfo &ei) { + const Color Them = (Us == WHITE ? BLACK : WHITE); - bool hasUnstoppable[2] = {false, false}; - int movesToGo[2] = {100, 100}; + 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); - for (Color us = WHITE; us <= BLACK; us++) + while (b) { - Color them = opposite_color(us); - Square ourKingSq = pos.king_square(us); - Square theirKingSq = pos.king_square(them); - Bitboard b = ei.pi->passed_pawns() & pos.pieces(PAWN, us), b2, b3, b4; + Square s = pop_1st_bit(&b); - while (b) - { - Square s = pop_1st_bit(&b); + assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN)); + assert(pos.pawn_is_passed(Us, s)); - assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN)); - assert(pos.pawn_is_passed(us, s)); + int r = int(relative_rank(Us, s) - RANK_2); + int tr = Max(0, r * (r - 1)); - int r = int(relative_rank(us, s) - RANK_2); - int tr = Max(0, r * (r - 1)); - Square blockSq = s + pawn_push(us); + // Base bonus based on rank + Value mbonus = Value(20 * tr); + Value ebonus = Value(10 + r * r * 10); - // Base bonus based on rank - Value mbonus = Value(20 * tr); - Value ebonus = Value(10 + r * r * 10); + // Adjust bonus based on king proximity + if (tr) + { + 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); - // Adjust bonus based on king proximity - if (tr != 0) + // If the pawn is free to advance, increase bonus + if (pos.square_is_empty(blockSq)) { - 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); + // There are no enemy pawns in the pawn's path + b2 = squares_in_front_of(Us, s); - // If the pawn is free to advance, increase bonus - if (pos.square_is_empty(blockSq)) - { - b2 = squares_in_front_of(us, s); - b3 = b2 & ei.attacked_by(them); - b4 = b2 & ei.attacked_by(us); - - // If there is an enemy rook or queen attacking the pawn from behind, - // add all X-ray attacks by the rook or queen. - if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s) - && (squares_behind(us, s) & pos.pieces(ROOK, QUEEN, them))) - b3 = b2; - - // Squares attacked or occupied by enemy pieces - b3 |= (b2 & pos.pieces_of_color(them)); - - // There are no enemy pawns in the pawn's path - assert((b2 & pos.pieces(PAWN, them)) == EmptyBoardBB); - - // Are any of the squares in the pawn's path attacked or occupied by the enemy? - if (b3 == EmptyBoardBB) - // No enemy attacks or pieces, huge bonus! - ebonus += Value(tr * (b2 == b4 ? 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 * ((b3 & b4) == b3 ? 13 : 8)); - - // At last, add a small bonus when there are no *friendly* pieces - // in the pawn's path. - if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB) - ebonus += Value(tr); - } - } + assert((b2 & pos.pieces(PAWN, Them)) == EmptyBoardBB); - // 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)) - ebonus += Value(r * 20); - else if (pos.attacks_from(s, them) & b2) - ebonus += Value(r * 12); + // Squares attacked by us + b4 = b2 & ei.attacked_by(Us); - // 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; + // Squares attacked or occupied by enemy pieces + b3 = b2 & (ei.attacked_by(Them) | pos.pieces_of_color(Them)); - 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 there is an enemy rook or queen attacking the pawn from behind, + // add all X-ray attacks by the rook or queen. + if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them)) + && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) + b3 = b2; - 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) - { - hasUnstoppable[us] = true; - movesToGo[us] = Min(movesToGo[us], mtg); - } - } + // Are any of the squares in the pawn's path attacked or occupied by the enemy? + if (b3 == EmptyBoardBB) + // No enemy attacks or pieces, huge bonus! + // Even bigger if we protect the pawn's path + ebonus += Value(tr * (b2 == b4 ? 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 * ((b3 & b4) == b3 ? 13 : 8)); + + // At last, add a small bonus when there are no *friendly* pieces + // in the pawn's path. + if ((b2 & pos.pieces_of_color(Us)) == EmptyBoardBB) + ebonus += Value(tr); } - // 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, - // we try the following: Increase the value for rook pawns if the - // other side has no pieces apart from a knight, and decrease the - // value if the other side has a rook or queen. - if (square_file(s) == FILE_A || square_file(s) == FILE_H) + } // 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)) + ebonus += Value(r * 20); + else if (pos.attacks_from(s, Them) & b2) + 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) { - if ( pos.non_pawn_material(them) <= KnightValueMidgame - && pos.piece_count(them, KNIGHT) <= 1) - ebonus += ebonus / 4; - else if (pos.pieces(ROOK, QUEEN, them)) - ebonus -= ebonus / 4; + 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] ? Min(movesToGo[Us], mtg) : mtg; } + } - // Add the scores for this pawn to the middle game and endgame eval. - ei.mgValue += apply_weight(Sign[us] * mbonus, WeightPassedPawnsMidgame); - ei.egValue += apply_weight(Sign[us] * ebonus, WeightPassedPawnsEndgame); + // 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, + // we try the following: Increase the value for rook pawns if the + // other side has no pieces apart from a knight, and decrease the + // value if the other side has a rook or queen. + if (square_file(s) == FILE_A || square_file(s) == FILE_H) + { + if ( pos.non_pawn_material(Them) <= KnightValueMidgame + && pos.piece_count(Them, KNIGHT) <= 1) + ebonus += ebonus / 4; + else if (pos.pieces(ROOK, QUEEN, Them)) + ebonus -= ebonus / 4; } - } + + // Add the scores for this pawn to the middle game and endgame eval. + ei.mgValue += apply_weight(Sign[Us] * mbonus, WeightPassedPawnsMidgame); + ei.egValue += apply_weight(Sign[Us] * ebonus, WeightPassedPawnsEndgame); + + } // while + } + + + // evaluate_passed_pawns() evaluates the passed pawns for both sides + + void evaluate_passed_pawns(const Position& pos, EvalInfo& ei) { + + int movesToGo[2] = {0, 0}; + + // Evaluate pawns for each color + evaluate_passed_pawns_of_color(pos, movesToGo, ei); + evaluate_passed_pawns_of_color(pos, movesToGo, ei); // Does either side have an unstoppable passed pawn? - if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) + if (movesToGo[WHITE] && !movesToGo[BLACK]) ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); - else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) + else if (movesToGo[BLACK] && !movesToGo[WHITE]) ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); - else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) + else if (movesToGo[BLACK] && movesToGo[WHITE]) { // Both sides have unstoppable pawns! Try to find out who queens // first. We begin by transforming 'movesToGo' to the number of @@ -1029,7 +1044,7 @@ namespace { // side wins. if (movesToGo[WHITE] <= movesToGo[BLACK] - 3) ei.egValue += UnstoppablePawnValue - Value(0x40 * (movesToGo[WHITE]/2)); - else if(movesToGo[BLACK] <= movesToGo[WHITE] - 3) + else if (movesToGo[BLACK] <= movesToGo[WHITE] - 3) ei.egValue -= UnstoppablePawnValue - Value(0x40 * (movesToGo[BLACK]/2)); // We could also add some rules about the situation when one side @@ -1045,8 +1060,8 @@ namespace { // (a2/h2 for black) is trapped by enemy pawns, and assigns a penalty // if it is. - void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us, - EvalInfo &ei) { + void evaluate_trapped_bishop_a7h7(const Position& pos, Square s, Color us, EvalInfo &ei) { + assert(square_is_ok(s)); assert(pos.piece_on(s) == piece_of_color_and_type(us, BISHOP)); @@ -1065,11 +1080,11 @@ namespace { // evaluate_trapped_bishop_a1h1() determines whether a bishop on a1/h1 // (a8/h8 for black) is trapped by a friendly pawn on b2/g2 (b7/g7 for - // black), and assigns a penalty if it is. This pattern can obviously + // black), and assigns a penalty if it is. This pattern can obviously // only occur in Chess960 games. - void evaluate_trapped_bishop_a1h1(const Position &pos, Square s, Color us, - EvalInfo &ei) { + void evaluate_trapped_bishop_a1h1(const Position& pos, Square s, Color us, EvalInfo& ei) { + Piece pawn = piece_of_color_and_type(us, PAWN); Square b2, b3, c3; @@ -1113,38 +1128,30 @@ namespace { // 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. - template - void evaluate_space(const Position &pos, Color us, EvalInfo &ei) { + template + void evaluate_space(const Position& pos, EvalInfo& ei) { - Color them = opposite_color(us); + 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 it is attacked by an enemy + // SpaceMask[us]. A square is unsafe if it is attacked by an enemy // pawn, or if it is undefended and attacked by an enemy piece. - Bitboard safeSquares = SpaceMask[us] - & ~pos.pieces(PAWN, us) - & ~ei.attacked_by(them, PAWN) - & ~(~ei.attacked_by(us) & ei.attacked_by(them)); + Bitboard safeSquares = SpaceMask[Us] + & ~pos.pieces(PAWN, Us) + & ~ei.attacked_by(Them, PAWN) + & ~(~ei.attacked_by(Us) & ei.attacked_by(Them)); // Find all squares which are at most three squares behind some friendly // pawn. - Bitboard behindFriendlyPawns = pos.pieces(PAWN, us); - if (us == WHITE) - { - behindFriendlyPawns |= (behindFriendlyPawns >> 8); - behindFriendlyPawns |= (behindFriendlyPawns >> 16); - } - else - { - behindFriendlyPawns |= (behindFriendlyPawns << 8); - behindFriendlyPawns |= (behindFriendlyPawns << 16); - } + Bitboard behindFriendlyPawns = pos.pieces(PAWN, Us); + behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 8 : behindFriendlyPawns << 8); + behindFriendlyPawns |= (Us == WHITE ? behindFriendlyPawns >> 16 : behindFriendlyPawns << 16); int space = count_1s_max_15(safeSquares) + count_1s_max_15(behindFriendlyPawns & safeSquares); - ei.mgValue += Sign[us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace); + ei.mgValue += Sign[Us] * apply_weight(Value(space * ei.mi->space_weight()), WeightSpace); } @@ -1172,23 +1179,17 @@ namespace { } - // compute_weight() computes the value of an evaluation weight, by combining + // weight_option() computes the value of an evaluation weight, by combining // an UCI-configurable weight with an internal weight. - int compute_weight(int uciWeight, int internalWeight) { + int weight_option(const std::string& opt, int internalWeight) { + int uciWeight = get_option_value_int(opt); uciWeight = (uciWeight * 0x100) / 100; return (uciWeight * internalWeight) / 0x100; } - // helper used in read_weights() - int weight_option(const std::string& opt, int weight) { - - return compute_weight(get_option_value_int(opt), weight); - } - - // init_safety() initizes the king safety evaluation, based on UCI // parameters. It is called from read_weights(). @@ -1213,9 +1214,9 @@ namespace { { if (i < b) SafetyTable[i] = Value(0); - else if(quad) + else if (quad) SafetyTable[i] = Value((int)(a * (i - b) * (i - b))); - else if(linear) + else if (linear) SafetyTable[i] = Value((int)(100 * a * (i - b))); }