X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=889a0013ed7a816fe22cf2393c1ff8a928c6cb65;hp=eb4cbef7be2eeedb9df4591dcc234eba618bedc2;hb=c7dd9b8d0cb3f5e55e0456c247ac1fd3583be6be;hpb=74033b004e9ba8c345573606ba670df75a795cba diff --git a/src/evaluate.cpp b/src/evaluate.cpp index eb4cbef7..889a0013 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -23,7 +23,6 @@ //// #include -#include #include "bitcount.h" #include "evaluate.h" @@ -39,6 +38,45 @@ namespace { + // 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]; + }; + const int Sign[2] = { 1, -1 }; // Evaluation grain size, must be a power of 2 @@ -188,25 +226,25 @@ namespace { // Function prototypes template - 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); 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); Value scale_by_game_phase(const Score& v, Phase ph, const ScaleFactor sf[]); @@ -230,69 +268,75 @@ void prefetchPawn(Key key, int threadID) { /// 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 w_mob, b_mob; assert(pos.is_ok()); assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS); assert(!pos.is_check()); - memset(&ei, 0, sizeof(EvalInfo)); - // Initialize by reading the incrementally updated scores included in the - // position object (material + piece square tables) - ei.value = pos.value(); + // position object (material + piece square tables). + Score value = pos.value(); + + // margins[color] stores 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); + value += 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]); + 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); - // Evaluate pieces - evaluate_pieces_of_color(pos, ei); - evaluate_pieces_of_color(pos, ei); + // Evaluate pieces and mobility + value += evaluate_pieces_of_color(pos, ei, w_mob) + - evaluate_pieces_of_color(pos, ei, b_mob); - // Kings. Kings are evaluated after all other pieces for both sides, - // because we need complete attack information for all pieces when computing + value += apply_weight(w_mob - b_mob, Weights[Mobility]); + + // Evaluate kings 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); + value += evaluate_king(pos, ei, margins) + - evaluate_king(pos, ei, margins); // Evaluate tactical threats, we need full attack info including king - evaluate_threats(pos, ei); - evaluate_threats(pos, ei); + value += evaluate_threats(pos, ei) + - evaluate_threats(pos, ei); // Evaluate passed pawns, we need full attack info including king - evaluate_passed_pawns(pos, ei); - evaluate_passed_pawns(pos, ei); + value += evaluate_passed_pawns(pos, ei) + - evaluate_passed_pawns(pos, ei); - Phase phase = ei.mi->game_phase(); + Phase phase = mi->game_phase(); // Middle-game specific evaluation terms if (phase > PHASE_ENDGAME) @@ -301,30 +345,27 @@ Value do_evaluate(const Position& pos, EvalInfo& ei) { 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); + 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); + 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) + if (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]); + value += 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(value) > VALUE_ZERO) + || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(value) < VALUE_ZERO))) { ScaleFactor sf; @@ -349,7 +390,7 @@ 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); + return Sign[pos.side_to_move()] * scale_by_game_phase(value, phase, factor); } } // namespace @@ -431,15 +472,15 @@ namespace { 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.kingAttackersCount[Us] = b ? count_1s_max_15(b) / 2 : 0; + ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[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); @@ -458,23 +499,26 @@ 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] = 0; + while ((s = *ptr++) != SQ_NONE) { // Find attacked squares, including x-ray attacks for bishops and rooks @@ -504,23 +548,23 @@ 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 @@ -531,9 +575,9 @@ 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 @@ -549,8 +593,8 @@ 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) @@ -558,11 +602,12 @@ 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; } @@ -570,7 +615,7 @@ 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); @@ -582,7 +627,7 @@ 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 // type of attacking piece, from knights to queens. Kings are not @@ -595,7 +640,7 @@ namespace { if (b & pos.pieces(pt2)) bonus += ThreatBonus[pt1][pt2]; } - ei.value += Sign[Us] * bonus; + return bonus; } @@ -603,29 +648,34 @@ 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 = SCORE_ZERO; + + 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); @@ -635,7 +685,7 @@ namespace { 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, Us, ksq); // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. @@ -649,10 +699,10 @@ namespace { // 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 @@ -666,39 +716,39 @@ namespace { // 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); } // 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); @@ -706,28 +756,32 @@ 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)); @@ -752,7 +806,7 @@ namespace { 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 @@ -761,7 +815,7 @@ 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. @@ -802,11 +856,12 @@ 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]); } @@ -826,8 +881,8 @@ namespace { // 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);