X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=132b8c1b4b7a5e6c3f081c94acef00b814f3a82a;hp=0a68387ebcdf4c629d6f58477e6e304345a34391;hb=f00c976bb22bc4dbcb2dbb0801f93fc8b6553a90;hpb=fff59319b01a9d0ef24e37e09027f5b58cb11136 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 0a68387e..132b8c1b 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -38,7 +38,44 @@ 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; + + // 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; @@ -91,18 +128,14 @@ namespace { V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0), V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0), V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0), - V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0), - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) }, + V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) }, { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0), V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0), V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0), - V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0), - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) } + V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) } }; // ThreatBonus[attacking][attacked] contains threat bonuses according to @@ -139,7 +172,7 @@ namespace { // 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] = { + const Bitboard SpaceMask[] = { (1ULL << SQ_C2) | (1ULL << SQ_D2) | (1ULL << SQ_E2) | (1ULL << SQ_F2) | (1ULL << SQ_C3) | (1ULL << SQ_D3) | (1ULL << SQ_E3) | (1ULL << SQ_F3) | (1ULL << SQ_C4) | (1ULL << SQ_D4) | (1ULL << SQ_E4) | (1ULL << SQ_F4), @@ -157,9 +190,10 @@ namespace { const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 }; // Bonuses for enemy's safe checks - const int QueenContactCheckBonus = 3; - const int QueenCheckBonus = 2; - const int RookCheckBonus = 1; + const int QueenContactCheckBonus = 6; + const int RookContactCheckBonus = 4; + const int QueenCheckBonus = 3; + const int RookCheckBonus = 2; const int BishopCheckBonus = 1; const int KnightCheckBonus = 1; @@ -187,28 +221,28 @@ namespace { // Function prototypes template - Value do_evaluate(const Position& pos, EvalInfo& ei); + Value do_evaluate(const Position& pos, Value& margin); template - void init_attack_tables(const Position& pos, EvalInfo& ei); + void init_eval_info(const Position& pos, EvalInfo& ei); template - Score 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& margin); 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); - Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]); + Score apply_weight(Score v, Score weight); + Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf); Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight); void init_safety(); } @@ -226,104 +260,90 @@ 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& margin) { - return CpuHasPOPCNT ? do_evaluate(pos, ei) - : do_evaluate(pos, ei); + return CpuHasPOPCNT ? do_evaluate(pos, margin) + : do_evaluate(pos, margin); } namespace { template -Value do_evaluate(const Position& pos, EvalInfo& ei) { +Value do_evaluate(const Position& pos, Value& margin) { - ScaleFactor factor[2]; - Score mobility; + EvalInfo ei; + Score mobilityWhite, mobilityBlack; assert(pos.is_ok()); assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS); assert(!pos.is_check()); - // Initialize by reading the incrementally updated scores included in the - // position object (material + piece square tables). - ei.value = pos.value(); + // Initialize value by reading the incrementally updated scores included + // in the position object (material + piece square tables). + Score bonus = pos.value(); + + // margin is the uncertainty estimation of position's evaluation + // and typically is used by the search for pruning decisions. + margin = 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); - - // After get_material_info() call that modifies them - factor[WHITE] = ei.mi->scale_factor(pos, WHITE); - factor[BLACK] = ei.mi->scale_factor(pos, BLACK); + if (mi->specialized_eval_exists()) + return mi->evaluate(pos); // Probe the pawn hash table ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos); - ei.value += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); + bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); - // Initialize attack bitboards with pawns evaluation - init_attack_tables(pos, ei); - init_attack_tables(pos, ei); + // Initialize attack and king safety bitboards + init_eval_info(pos, ei); + init_eval_info(pos, ei); // Evaluate pieces and mobility - mobility = evaluate_pieces_of_color(pos, ei) - - evaluate_pieces_of_color(pos, ei); - ei.value += apply_weight(mobility, Weights[Mobility]); + bonus += evaluate_pieces_of_color(pos, ei, mobilityWhite) + - evaluate_pieces_of_color(pos, ei, mobilityBlack); - // 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); + bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]); - // Evaluate tactical threats, we need full attack info including king - evaluate_threats(pos, ei); - evaluate_threats(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, margin) + - evaluate_king(pos, ei, margin); - // Evaluate passed pawns, we need full attack info including king - evaluate_passed_pawns(pos, ei); - evaluate_passed_pawns(pos, ei); + // Evaluate tactical threats, we need full attack information including king + bonus += evaluate_threats(pos, ei) + - evaluate_threats(pos, ei); - Phase phase = ei.mi->game_phase(); + // Evaluate passed pawns, we need full attack information including king + bonus += evaluate_passed_pawns(pos, ei) + - evaluate_passed_pawns(pos, ei); - // Middle-game specific evaluation terms - if (phase > PHASE_ENDGAME) + // Evaluate space for both sides, only in middle-game. + if (mi->space_weight()) { - // 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) - - ei.value += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0); - - // Evaluate space for both sides - if (ei.mi->space_weight() > 0) - { - int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); - ei.value += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]); - } + int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); + bonus += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]); } + // Scale winning side if position is more drawish that what it appears + ScaleFactor sf = eg_value(bonus) > VALUE_ZERO ? mi->scale_factor(pos, WHITE) + : mi->scale_factor(pos, BLACK); + Phase phase = mi->game_phase(); + // If we don't already have an unusual scale factor, check for opposite - // colored bishop endgames, and use a lower scale for those + // 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))) + && sf == SCALE_FACTOR_NORMAL) { - ScaleFactor sf; - // Only the two bishops ? if ( pos.non_pawn_material(WHITE) == BishopValueMidgame && pos.non_pawn_material(BLACK) == BishopValueMidgame) @@ -337,19 +357,16 @@ Value do_evaluate(const Position& pos, EvalInfo& ei) { // Endgame with opposite-colored bishops, but also other pieces. Still // a bit drawish, but not as drawish as with only the two bishops. sf = ScaleFactor(50); - - if (factor[WHITE] == SCALE_FACTOR_NORMAL) - factor[WHITE] = sf; - if (factor[BLACK] == SCALE_FACTOR_NORMAL) - factor[BLACK] = sf; } // 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, sf); + return pos.side_to_move() == WHITE ? v : -v; } } // namespace + /// init_eval() initializes various tables used by the evaluation function void init_eval(int threads) { @@ -358,18 +375,19 @@ 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(); } } @@ -378,13 +396,7 @@ 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); } @@ -415,27 +427,35 @@ 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 BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; 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]; - ei.kingAttackersCount[Us] = b ? count_1s_max_15(b) / 2 : 0; - ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; + + // Init king safety tables only if we are going to use them + if ( pos.piece_count(Us, QUEEN) + && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame) + { + ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8)); + b &= ei.attackedBy[Us][PAWN]; + ei.kingAttackersCount[Us] = b ? count_1s(b) / 2 : 0; + ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; + } else + ei.kingZone[Us] = ei.kingAttackersCount[Us] = 0; } // 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); @@ -445,7 +465,7 @@ 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 @@ -454,25 +474,27 @@ 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 - Score evaluate_pieces(const Position& pos, EvalInfo& ei, Bitboard no_mob_area) { + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) { Bitboard b; Square s, ksq; int mob; File f; - Score mobility = SCORE_ZERO; + Score bonus = SCORE_ZERO; + const BitCountType Full = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64 : CNT32; + const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; const Color Them = (Us == WHITE ? BLACK : WHITE); const Square* ptr = pos.piece_list_begin(Us, Piece); - ei.attackedBy[Us][Piece] = 0; + ei.attackedBy[Us][Piece] = EmptyBoardBB; while ((s = *ptr++) != SQ_NONE) { @@ -496,30 +518,30 @@ namespace { ei.kingAttackersWeight[Us] += KingAttackWeights[Piece]; Bitboard bb = (b & ei.attackedBy[Them][KING]); if (bb) - ei.kingAdjacentZoneAttacksCount[Us] += count_1s_max_15(bb); + ei.kingAdjacentZoneAttacksCount[Us] += count_1s(bb); } // Mobility - mob = (Piece != QUEEN ? count_1s_max_15(b & no_mob_area) - : count_1s(b & no_mob_area)); + mob = (Piece != QUEEN ? count_1s(b & mobilityArea) + : count_1s(b & mobilityArea)); 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 @@ -530,9 +552,9 @@ 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 @@ -548,8 +570,8 @@ 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) @@ -557,12 +579,12 @@ 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 mobility; + return bonus; } @@ -570,7 +592,7 @@ 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); @@ -582,11 +604,11 @@ 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; @@ -595,7 +617,7 @@ namespace { if (b & pos.pieces(pt2)) bonus += ThreatBonus[pt1][pt2]; } - ei.value += Sign[Us] * bonus; + return bonus; } @@ -603,53 +625,48 @@ namespace { // pieces of a given color. template - Score 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 mobility = SCORE_ZERO; + 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)); + const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); - mobility += evaluate_pieces(pos, ei, no_mob_area); - mobility += evaluate_pieces(pos, ei, no_mob_area); - mobility += evaluate_pieces(pos, ei, no_mob_area); - mobility += evaluate_pieces(pos, ei, no_mob_area); + bonus += evaluate_pieces(pos, ei, mobility, mobilityArea); + bonus += evaluate_pieces(pos, ei, mobility, mobilityArea); + bonus += evaluate_pieces(pos, ei, mobility, mobilityArea); + bonus += evaluate_pieces(pos, ei, mobility, mobilityArea); // 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 mobility; + 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& margin) { + const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; 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.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.attackedBy[Them][0] & ei.attackedBy[Us][KING]; @@ -663,9 +680,9 @@ namespace { // attacked and undefended squares around our king, the square of the // king, and the quality of the pawn shelter. attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) - + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s_max_15(undefended)) + + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s(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... @@ -676,7 +693,27 @@ namespace { 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(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(b) + * (Them == pos.side_to_move() ? 2 : 1); } // Analyse enemy's safe distance checks for sliders and knights @@ -688,42 +725,43 @@ namespace { // Enemy queen safe checks b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; if (b) - attackUnits += QueenCheckBonus * count_1s_max_15(b); + attackUnits += QueenCheckBonus * count_1s(b); // Enemy rooks safe checks b = b1 & ei.attackedBy[Them][ROOK]; if (b) - attackUnits += RookCheckBonus * count_1s_max_15(b); + attackUnits += RookCheckBonus * count_1s(b); // Enemy bishops safe checks b = b2 & ei.attackedBy[Them][BISHOP]; if (b) - attackUnits += BishopCheckBonus * count_1s_max_15(b); + attackUnits += BishopCheckBonus * count_1s(b); // Enemy knights safe checks b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe; if (b) - attackUnits += KnightCheckBonus * count_1s_max_15(b); + attackUnits += KnightCheckBonus * count_1s(b); // To index KingDangerTable[] attackUnits must be in [0, 99] range 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.margin[] + // 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.margin[Us] = mg_value(KingDangerTable[Us][attackUnits]); - } else - ei.margin[Us] = VALUE_ZERO; + bonus -= KingDangerTable[Us][attackUnits]; + if (pos.side_to_move() == Us) + margin += 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); @@ -732,7 +770,7 @@ namespace { Bitboard b = ei.pi->passed_pawns(Us); if (!b) - return; + return SCORE_ZERO; do { Square s = pop_1st_bit(&b); @@ -740,20 +778,20 @@ namespace { 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)) @@ -773,20 +811,20 @@ namespace { // 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. @@ -814,7 +852,7 @@ namespace { } while (b); // Add the scores to the middle game and endgame eval - ei.value += Sign[Us] * apply_weight(bonus, Weights[PassedPawns]); + return apply_weight(bonus, Weights[PassedPawns]); } @@ -823,14 +861,15 @@ 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 BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; 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) @@ -842,29 +881,29 @@ namespace { behind |= (Us == WHITE ? behind >> 8 : behind << 8); behind |= (Us == WHITE ? behind >> 16 : behind << 16); - return count_1s_max_15(safe) + count_1s_max_15(behind & safe); + return count_1s(safe) + count_1s(behind & safe); } // 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); } // scale_by_game_phase() interpolates between a middle game and an endgame score, // based on game phase. It also scales the return value by a ScaleFactor array. - Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]) { + Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf) { assert(mg_value(v) > -VALUE_INFINITE && mg_value(v) < VALUE_INFINITE); assert(eg_value(v) > -VALUE_INFINITE && eg_value(v) < VALUE_INFINITE); assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME); Value eg = eg_value(v); - ScaleFactor f = sf[eg > VALUE_ZERO ? WHITE : BLACK]; - Value ev = Value((eg * int(f)) / SCALE_FACTOR_NORMAL); + Value ev = Value((eg * int(sf)) / SCALE_FACTOR_NORMAL); int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128; return Value(result & ~(GrainSize - 1)); @@ -883,6 +922,7 @@ 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().