X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=69f0e4c27fa75e4caff8b23db06d911e23819de6;hp=cb03ba25ced51d02b0b9b8ca7914d59ff486ac9e;hb=cedbd3332a4a1574e701bda098a9df1153e299c6;hpb=045beac156a97669d3d4ddbc53eceae4be1e5186 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index cb03ba25..69f0e4c2 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -17,12 +17,10 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include +#include +#include +#include #include "bitcount.h" #include "evaluate.h" @@ -31,44 +29,35 @@ #include "thread.h" #include "ucioption.h" - -//// -//// Local definitions -//// - namespace { // 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]; + // Pointers to material and pawn hash table entries + MaterialEntry* mi; + PawnEntry* 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 + // kingRing[color] is the zone around the 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, + // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8, // f7, g7, h7, f6, g6 and h6. - Bitboard kingZone[2]; + Bitboard kingRing[2]; // kingAttackersCount[color] is the number of pieces of the given color - // which attack a square in the kingZone of the enemy king. + // which attack a square in the kingRing 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 + // given color which attack a square in the kingRing of the enemy king. The // weights of the individual piece types are given by the variables // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and // KnightAttackWeight in evaluate.cpp @@ -86,7 +75,7 @@ namespace { const int GrainSize = 8; // Evaluation weights, initialized from UCI options - enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem }; + enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem }; Score Weights[6]; typedef Value V; @@ -99,7 +88,7 @@ namespace { // // Values modified by Joona Kiiski const Score WeightsInternal[] = { - S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0) + S(252, 344), S(216, 266), S(46, 0), S(247, 0), S(259, 0) }; // MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and @@ -133,18 +122,14 @@ 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 @@ -153,30 +138,45 @@ namespace { {}, {}, { 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 - { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK + { S(0, 0), S( 0, 22), S(15, 49), S(15, 49), S( 0, 0), S(24, 49) }, // ROOK { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN }; - // ThreatedByPawnPenalty[PieceType] contains a penalty according to which + // ThreatenedByPawnPenalty[PieceType] contains a penalty according to which // piece type is attacked by an enemy pawn. - const Score ThreatedByPawnPenalty[] = { + const Score ThreatenedByPawnPenalty[] = { S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118) }; #undef S - // Rooks and queens on the 7th rank (modified by Joona Kiiski) - const Score RookOn7thBonus = make_score(47, 98); - const Score QueenOn7thBonus = make_score(27, 54); + // Bonus for having the side to move (modified by Joona Kiiski) + const Score Tempo = make_score(24, 11); + + // Rooks and queens on the 7th rank + const Score RookOn7thBonus = make_score(3, 20); + const Score QueenOn7thBonus = make_score(1, 8); + + // Rooks and queens attacking pawns on the same rank + const Score RookOnPawnBonus = make_score(3, 48); + const Score QueenOnPawnBonus = make_score(1, 40); // Rooks on open files (modified by Joona Kiiski) - const Score RookOpenFileBonus = make_score(43, 43); - const Score RookHalfOpenFileBonus = make_score(19, 19); + const Score RookOpenFileBonus = make_score(43, 21); + const Score RookHalfOpenFileBonus = make_score(19, 10); // Penalty for rooks trapped inside a friendly king which has lost the // right to castle. const Value TrappedRookPenalty = Value(180); + // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by + // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only + // happen in Chess960 games. + const Score TrappedBishopA1H1Penalty = make_score(100, 100); + + // Penalty for an undefended bishop or knight + const Score UndefendedMinorPenalty = make_score(25, 10); + // 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 @@ -223,140 +223,231 @@ namespace { // weighted scores, indexed by color and by a calculated integer number. Score KingDangerTable[2][128]; - // Pawn and material hash tables, indexed by the current thread id. - // Note that they will be initialized at 0 being global variables. - MaterialInfoTable* MaterialTable[MAX_THREADS]; - PawnInfoTable* PawnTable[MAX_THREADS]; + // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the + // evaluation terms, used when tracing. + Score TracedScores[2][16]; + std::stringstream TraceStream; + + enum TracedType { + PST = 8, IMBALANCE = 9, MOBILITY = 10, THREAT = 11, + PASSED = 12, UNSTOPPABLE = 13, SPACE = 14, TOTAL = 15 + }; // Function prototypes - template + template Value do_evaluate(const Position& pos, Value& margin); - template + template void init_eval_info(const Position& pos, EvalInfo& ei); - template + template Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility); - template - Score evaluate_king(const Position& pos, EvalInfo& ei, Value& margin); + template + Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]); template Score evaluate_threats(const Position& pos, EvalInfo& ei); - template + template int evaluate_space(const Position& pos, EvalInfo& ei); template Score evaluate_passed_pawns(const Position& pos, EvalInfo& ei); - Score apply_weight(Score v, Score weight); - Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf); + Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei); + + Value interpolate(const Score& v, Phase ph, ScaleFactor sf); Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight); - void init_safety(); + double to_cp(Value v); + void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO); + void trace_row(const char* name, int idx); } -//// -//// Functions -//// +namespace Eval { + Color RootColor; + Value ContemptFactor; + Value ValueDraw[2]; -/// Prefetches in pawn hash tables + /// 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. -void prefetchPawn(Key key, int threadID) { + Value evaluate(const Position& pos, Value& margin) { + return do_evaluate(pos, margin); + } - PawnTable[threadID]->prefetch(key); -} + /// init() computes evaluation weights from the corresponding UCI parameters + /// and setup king tables. -/// 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, Value& margin) { + void init() { + + Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]); + Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]); + Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]); + Weights[KingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]); + Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]); + + // King safety is asymmetrical. Our king danger level is weighted by + // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness". + // If running in analysis mode, make sure we use symmetrical king safety. We + // do this by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] + // by their average. + if (Options["UCI_AnalyseMode"]) + Weights[KingDangerUs] = Weights[KingDangerThem] = (Weights[KingDangerUs] + Weights[KingDangerThem]) / 2; + + const int MaxSlope = 30; + const int Peak = 1280; + + for (int t = 0, i = 1; i < 100; i++) + { + t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope)); + + KingDangerTable[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]); + KingDangerTable[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]); + } + + if (Options["UCI_AnalyseMode"]) + ContemptFactor = VALUE_ZERO; + else + ContemptFactor = Options["Contempt Factor"] * PawnValueMg / 100; + } + + + /// trace() is like evaluate() but instead of a value returns a string suitable + /// to be print on stdout with the detailed descriptions and values of each + /// evaluation term. Used mainly for debugging. + + std::string trace(const Position& pos) { + + Value margin; + std::string totals; + + RootColor = pos.side_to_move(); + + TraceStream.str(""); + TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2); + memset(TracedScores, 0, 2 * 16 * sizeof(Score)); + + do_evaluate(pos, margin); + + totals = TraceStream.str(); + TraceStream.str(""); + + TraceStream << std::setw(21) << "Eval term " << "| White | Black | Total \n" + << " | MG EG | MG EG | MG EG \n" + << "---------------------+-------------+-------------+---------------\n"; + + trace_row("Material, PST, Tempo", PST); + trace_row("Material imbalance", IMBALANCE); + trace_row("Pawns", PAWN); + trace_row("Knights", KNIGHT); + trace_row("Bishops", BISHOP); + trace_row("Rooks", ROOK); + trace_row("Queens", QUEEN); + trace_row("Mobility", MOBILITY); + trace_row("King safety", KING); + trace_row("Threats", THREAT); + trace_row("Passed pawns", PASSED); + trace_row("Unstoppable pawns", UNSTOPPABLE); + trace_row("Space", SPACE); + + TraceStream << "---------------------+-------------+-------------+---------------\n"; + trace_row("Total", TOTAL); + TraceStream << totals; + + return TraceStream.str(); + } + +} // namespace Eval - return CpuHasPOPCNT ? do_evaluate(pos, margin) - : do_evaluate(pos, margin); -} namespace { -template +template Value do_evaluate(const Position& pos, Value& margin) { - EvalInfo ei; - Score mobilityWhite, mobilityBlack; + assert(!pos.in_check()); - assert(pos.is_ok()); - assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS); - assert(!pos.is_check()); + EvalInfo ei; + Value margins[2]; + Score score, mobilityWhite, mobilityBlack; - // Initialize value by reading the incrementally updated scores included - // in the position object (material + piece square tables). - Score bonus = pos.value(); + // margins[] store the uncertainty estimation of position's evaluation + // that typically is used by the search for pruning decisions. + margins[WHITE] = margins[BLACK] = VALUE_ZERO; - // margin is the uncertainty estimation of position's evaluation - // and typically is used by the search for pruning decisions. - margin = VALUE_ZERO; + // Initialize score by reading the incrementally updated scores included + // in the position object (material + piece square tables) and adding + // Tempo bonus. Score is computed from the point of view of white. + score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo); // Probe the material hash table - MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos); - bonus += mi->material_value(); + ei.mi = pos.this_thread()->materialTable.probe(pos); + score += ei.mi->material_value(); // If we have a specialized evaluation function for the current material // configuration, call it and return. - if (mi->specialized_eval_exists()) - return mi->evaluate(pos); + if (ei.mi->specialized_eval_exists()) + { + margin = VALUE_ZERO; + return ei.mi->evaluate(pos); + } // Probe the pawn hash table - ei.pi = PawnTable[pos.thread()]->get_pawn_info(pos); - bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); + ei.pi = pos.this_thread()->pawnTable.probe(pos); + score += ei.pi->pawns_value(); // Initialize attack and king safety bitboards - init_eval_info(pos, ei); - init_eval_info(pos, ei); + init_eval_info(pos, ei); + init_eval_info(pos, ei); // Evaluate pieces and mobility - bonus += evaluate_pieces_of_color(pos, ei, mobilityWhite) - - evaluate_pieces_of_color(pos, ei, mobilityBlack); + score += evaluate_pieces_of_color(pos, ei, mobilityWhite) + - evaluate_pieces_of_color(pos, ei, mobilityBlack); - bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]); + score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]); // 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); + score += evaluate_king(pos, ei, margins) + - evaluate_king(pos, ei, margins); // Evaluate tactical threats, we need full attack information including king - bonus += evaluate_threats(pos, ei) + score += evaluate_threats(pos, ei) - evaluate_threats(pos, ei); // Evaluate passed pawns, we need full attack information including king - bonus += evaluate_passed_pawns(pos, ei) + score += evaluate_passed_pawns(pos, ei) - evaluate_passed_pawns(pos, ei); - Phase phase = mi->game_phase(); + // If one side has only a king, check whether exists any unstoppable passed pawn + if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK)) + score += evaluate_unstoppable_pawns(pos, ei); // Evaluate space for both sides, only in middle-game. - if (phase > PHASE_ENDGAME && mi->space_weight() > 0) + if (ei.mi->space_weight()) { - int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); - bonus += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]); + int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); + score += apply_weight(make_score(s * ei.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); + ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE) + : ei.mi->scale_factor(pos, BLACK); // 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() + if ( ei.mi->game_phase() < PHASE_MIDGAME + && pos.opposite_bishops() && sf == SCALE_FACTOR_NORMAL) { // Only the two bishops ? - if ( pos.non_pawn_material(WHITE) == BishopValueMidgame - && pos.non_pawn_material(BLACK) == BishopValueMidgame) + if ( pos.non_pawn_material(WHITE) == BishopValueMg + && pos.non_pawn_material(BLACK) == BishopValueMg) { // Check for KBP vs KB with only a single pawn that is almost // certainly a draw or at least two pawns. @@ -369,92 +460,57 @@ Value do_evaluate(const Position& pos, Value& margin) { sf = ScaleFactor(50); } - // Interpolate between the middle game and the endgame score - 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 + margin = margins[pos.side_to_move()]; + Value v = interpolate(score, ei.mi->game_phase(), sf); -void init_eval(int threads) { - - assert(threads <= MAX_THREADS); - - for (int i = 0; i < MAX_THREADS; i++) + // In case of tracing add all single evaluation contributions for both white and black + if (Trace) { - 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(); + trace_add(PST, pos.psq_score()); + trace_add(IMBALANCE, ei.mi->material_value()); + trace_add(PAWN, ei.pi->pawns_value()); + trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility])); + trace_add(THREAT, evaluate_threats(pos, ei), evaluate_threats(pos, ei)); + trace_add(PASSED, evaluate_passed_pawns(pos, ei), evaluate_passed_pawns(pos, ei)); + trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei)); + Score w = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0); + Score b = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0); + trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space])); + trace_add(TOTAL, score); + TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE]) + << ", Black: " << to_cp(margins[BLACK]) + << "\nScaling: " << std::noshowpos + << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, " + << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * " + << std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n" + << "Total evaluation: " << to_cp(v); } -} - - -/// quit_eval() releases heap-allocated memory at program termination - -void quit_eval() { - - init_eval(0); -} - - -/// read_weights() reads evaluation weights from the corresponding UCI parameters - -void read_weights(Color us) { - - // King safety is asymmetrical. Our king danger level is weighted by - // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness". - const int kingDangerUs = (us == WHITE ? KingDangerUs : KingDangerThem); - const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs); - Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]); - Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]); - Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]); - Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]); - Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]); - Weights[kingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]); - - // If running in analysis mode, make sure we use symmetrical king safety. We do this - // by replacing both Weights[kingDangerUs] and Weights[kingDangerThem] by their average. - if (get_option_value_bool("UCI_AnalyseMode")) - Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2; - - init_safety(); + return pos.side_to_move() == WHITE ? v : -v; } -namespace { - // init_eval_info() initializes king bitboards for given color adding // pawn attacks. To be done at the beginning of the evaluation. - template + template 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); - ei.updateKingTables[Us] = pos.piece_count(Us, QUEEN) && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame; - if (ei.updateKingTables[Us]) + + // Init king safety tables only if we are going to use them + if ( pos.piece_count(Us, QUEEN) + && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg) { + ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8)); b &= ei.attackedBy[Us][PAWN]; - ei.kingAttackersCount[Us] = b ? count_1s_max_15(b) / 2 : EmptyBoardBB; - ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = EmptyBoardBB; - } + ei.kingAttackersCount[Us] = b ? popcount(b) / 2 : 0; + ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; + } else + ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0; } @@ -472,10 +528,10 @@ namespace { // Increase bonus if supported by pawn, especially if the opponent has // no minor piece which can exchange the outpost piece. - if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s)) + if (bonus && (ei.attackedBy[Us][PAWN] & s)) { - if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB - && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB) + if ( !pos.pieces(Them, KNIGHT) + && !(same_color_squares(s) & pos.pieces(Them, BISHOP))) bonus += bonus + bonus / 2; else bonus += bonus / 2; @@ -486,79 +542,116 @@ namespace { // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color - template + template Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) { Bitboard b; Square s, ksq; int mob; File f; - Score bonus = SCORE_ZERO; + Score score = SCORE_ZERO; const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square* ptr = pos.piece_list_begin(Us, Piece); + const Square* pl = pos.piece_list(Us, Piece); - ei.attackedBy[Us][Piece] = EmptyBoardBB; + ei.attackedBy[Us][Piece] = 0; - while ((s = *ptr++) != SQ_NONE) + while ((s = *pl++) != SQ_NONE) { // Find attacked squares, including x-ray attacks for bishops and rooks if (Piece == KNIGHT || Piece == QUEEN) b = pos.attacks_from(s); else if (Piece == BISHOP) - b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(QUEEN, Us)); + b = attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN)); else if (Piece == ROOK) - b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.pieces(ROOK, QUEEN, Us)); + b = attacks_bb(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)); else assert(false); - // Update attack info ei.attackedBy[Us][Piece] |= b; - // King attacks - if (ei.updateKingTables[Us] && (b & ei.kingZone[Us])) + if (b & ei.kingRing[Them]) { ei.kingAttackersCount[Us]++; 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] += popcount(bb); } - // Mobility - mob = (Piece != QUEEN ? count_1s_max_15(b & mobilityArea) - : count_1s(b & mobilityArea)); + mob = (Piece != QUEEN ? popcount(b & mobilityArea) + : popcount(b & mobilityArea)); mobility += MobilityBonus[Piece][mob]; + // Add a bonus if a slider is pinning an enemy piece + if ( (Piece == BISHOP || Piece == ROOK || Piece == QUEEN) + && (PseudoAttacks[Piece][pos.king_square(Them)] & s)) + { + b = BetweenBB[s][pos.king_square(Them)] & pos.pieces(); + + assert(b); + + if (!more_than_one(b) && (b & pos.pieces(Them))) + score += ThreatBonus[Piece][type_of(pos.piece_on(lsb(b)))]; + } + // 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)) - bonus -= ThreatedByPawnPenalty[Piece]; + if (ei.attackedBy[Them][PAWN] & s) + score -= ThreatenedByPawnPenalty[Piece]; // Bishop and knight outposts squares - if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us)) - bonus += evaluate_outposts(pos, ei, s); + if ( (Piece == BISHOP || Piece == KNIGHT) + && !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s))) + score += evaluate_outposts(pos, ei, s); + + if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5) + { + // Major piece on 7th rank + if ( relative_rank(Us, s) == RANK_7 + && relative_rank(Us, pos.king_square(Them)) == RANK_8) + score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); + + // Major piece attacking pawns on the same rank + Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s); + if (pawns) + score += (Piece == ROOK ? RookOnPawnBonus + : QueenOnPawnBonus) * popcount(pawns); + } - // 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) + // Special extra evaluation for bishops + if (Piece == BISHOP && pos.is_chess960()) { - bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); + // An important Chess960 pattern: A cornered bishop blocked by + // a friendly pawn diagonally in front of it is a very serious + // problem, especially when that pawn is also blocked. + if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)) + { + Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W); + if (pos.piece_on(s + d) == make_piece(Us, PAWN)) + { + if (!pos.is_empty(s + d + pawn_push(Us))) + score -= 2*TrappedBishopA1H1Penalty; + else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN)) + score -= TrappedBishopA1H1Penalty; + else + score -= TrappedBishopA1H1Penalty / 2; + } + } } // Special extra evaluation for rooks if (Piece == ROOK) { // Open and half-open files - f = square_file(s); + f = file_of(s); if (ei.pi->file_is_half_open(Us, f)) { if (ei.pi->file_is_half_open(Them, f)) - bonus += RookOpenFileBonus; + score += RookOpenFileBonus; else - bonus += RookHalfOpenFileBonus; + score += RookHalfOpenFileBonus; } // Penalize rooks which are trapped inside a king. Penalize more if @@ -568,27 +661,31 @@ namespace { ksq = pos.king_square(Us); - if ( square_file(ksq) >= FILE_E - && square_file(s) > square_file(ksq) - && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) + if ( file_of(ksq) >= FILE_E + && file_of(s) > file_of(ksq) + && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s))) { // 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))) - bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + if (!ei.pi->has_open_file_to_right(Us, file_of(ksq))) + score -= 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) - && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s))) + else if ( file_of(ksq) <= FILE_D + && file_of(s) < file_of(ksq) + && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s))) { // Is there a half-open file between the king and the edge of the board? - if (!ei.pi->has_open_file_to_left(Us, square_file(ksq))) - bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 + if (!ei.pi->has_open_file_to_left(Us, file_of(ksq))) + score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2 : (TrappedRookPenalty - mob * 16), 0); } } } - return bonus; + + if (Trace) + TracedScores[Us][Piece] = score; + + return score; } @@ -600,15 +697,25 @@ namespace { const Color Them = (Us == WHITE ? BLACK : WHITE); - Bitboard b; - Score bonus = SCORE_ZERO; + Bitboard b, undefendedMinors, weakEnemies; + Score score = SCORE_ZERO; + + // Undefended minors get penalized even if not under attack + undefendedMinors = pos.pieces(Them) + & (pos.pieces(BISHOP) | pos.pieces(KNIGHT)) + & ~ei.attackedBy[Them][0]; + + if (undefendedMinors) + score += more_than_one(undefendedMinors) ? UndefendedMinorPenalty * 2 + : UndefendedMinorPenalty; // Enemy pieces not defended by a pawn and under our attack - Bitboard weakEnemies = pos.pieces_of_color(Them) - & ~ei.attackedBy[Them][PAWN] - & ei.attackedBy[Us][0]; + weakEnemies = pos.pieces(Them) + & ~ei.attackedBy[Them][PAWN] + & ei.attackedBy[Us][0]; + if (!weakEnemies) - return SCORE_ZERO; + return score; // Add bonus according to type of attacked enemy piece and to the // type of attacking piece, from knights to queens. Kings are not @@ -619,42 +726,42 @@ namespace { if (b) for (PieceType pt2 = PAWN; pt2 < KING; pt2++) if (b & pos.pieces(pt2)) - bonus += ThreatBonus[pt1][pt2]; + score += ThreatBonus[pt1][pt2]; } - return bonus; + return score; } // evaluate_pieces_of_color<>() assigns bonuses and penalties to all the // pieces of a given color. - template + template Score evaluate_pieces_of_color(const Position& pos, EvalInfo& ei, Score& mobility) { const Color Them = (Us == WHITE ? BLACK : WHITE); - Score bonus = mobility = SCORE_ZERO; + Score score = mobility = SCORE_ZERO; // Do not include in mobility squares protected by enemy pawns or occupied by our pieces - const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us)); + const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us)); - 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); + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += evaluate_pieces(pos, ei, mobility, mobilityArea); + score += 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 bonus; + return score; } // evaluate_king<>() assigns bonuses and penalties to a king of a given color - template - Score evaluate_king(const Position& pos, EvalInfo& ei, Value& margin) { + template + Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -662,13 +769,12 @@ namespace { int attackUnits; const Square ksq = pos.king_square(Us); - // King shelter - Score bonus = ei.pi->king_shelter(pos, ksq); + // King shelter and enemy pawns storm + Score score = ei.pi->king_safety(pos, ksq); // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. - if ( ei.updateKingTables[Them] - && ei.kingAttackersCount[Them] >= 2 + if ( ei.kingAttackersCount[Them] >= 2 && ei.kingAdjacentZoneAttacksCount[Them]) { // Find the attacked squares around the king which has no defenders @@ -683,14 +789,14 @@ namespace { // the number and types of the enemy's attacking pieces, the number of // 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)) + attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2) + + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount(undefended)) + InitKingDanger[relative_square(Us, ksq)] - - mg_value(ei.pi->king_shelter(pos, ksq)) / 32; + - mg_value(score) / 32; // Analyse enemy's safe queen contact checks. First find undefended // squares around the king attacked by enemy queen... - b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces_of_color(Them); + b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them); if (b) { // ...then remove squares not supported by another enemy piece @@ -698,16 +804,16 @@ namespace { | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]); if (b) attackUnits += QueenContactCheckBonus - * count_1s_max_15(b) + * popcount(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); + b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them); // Consider only squares where the enemy rook gives check - b &= RookPseudoAttacks[ksq]; + b &= PseudoAttacks[ROOK][ksq]; if (b) { @@ -716,12 +822,12 @@ namespace { | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]); if (b) attackUnits += RookContactCheckBonus - * count_1s_max_15(b) + * popcount(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.attackedBy[Us][0]); + safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]); b1 = pos.attacks_from(ksq) & safe; b2 = pos.attacks_from(ksq) & safe; @@ -729,36 +835,39 @@ namespace { // Enemy queen safe checks b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; if (b) - attackUnits += QueenCheckBonus * count_1s_max_15(b); + attackUnits += QueenCheckBonus * popcount(b); // Enemy rooks safe checks b = b1 & ei.attackedBy[Them][ROOK]; if (b) - attackUnits += RookCheckBonus * count_1s_max_15(b); + attackUnits += RookCheckBonus * popcount(b); // Enemy bishops safe checks b = b2 & ei.attackedBy[Them][BISHOP]; if (b) - attackUnits += BishopCheckBonus * count_1s_max_15(b); + attackUnits += BishopCheckBonus * popcount(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 * popcount(b); // To index KingDangerTable[] attackUnits must be in [0, 99] range - attackUnits = Min(99, Max(0, attackUnits)); + attackUnits = std::min(99, std::max(0, attackUnits)); // Finally, extract the king danger score from the KingDangerTable[] // 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. - bonus -= KingDangerTable[Us][attackUnits]; - if (pos.side_to_move() == Us) - margin += mg_value(KingDangerTable[Us][attackUnits]); + score -= KingDangerTable[Us == Eval::RootColor][attackUnits]; + margins[Us] += mg_value(KingDangerTable[Us == Eval::RootColor][attackUnits]); } - return bonus; + + if (Trace) + TracedScores[Us][KING] = score; + + return score; } @@ -769,15 +878,16 @@ namespace { const Color Them = (Us == WHITE ? BLACK : WHITE); - Score bonus = SCORE_ZERO; - Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns; - Bitboard b = ei.pi->passed_pawns(Us); + Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns; + Score score = SCORE_ZERO; + + b = ei.pi->passed_pawns(Us); if (!b) return SCORE_ZERO; do { - Square s = pop_1st_bit(&b); + Square s = pop_lsb(&b); assert(pos.pawn_is_passed(Us, s)); @@ -793,24 +903,27 @@ namespace { Square blockSq = s + pawn_push(Us); // Adjust bonus based on kings proximity - 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); + ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr); + ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr); + + // If blockSq is not the queening square then consider also a second push + if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1)) + ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr); // If the pawn is free to advance, increase bonus - if (pos.square_is_empty(blockSq)) + if (pos.is_empty(blockSq)) { - squaresToQueen = squares_in_front_of(Us, s); + squaresToQueen = forward_bb(Us, s); 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 // the squares in the pawn's path attacked or occupied by the enemy. - if ( (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them)) - && (squares_behind(Us, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) + if ( (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN)) + && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from(s))) unsafeSquares = squaresToQueen; else - unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces_of_color(Them)); + unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(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. @@ -822,19 +935,15 @@ namespace { // If yes, big bonus (but smaller than when there are no enemy attacks), // if no, somewhat smaller bonus. 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(rr); } } // 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. - supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s); + supportingPawns = pos.pieces(Us, PAWN) & adjacent_files_bb(file_of(s)); if (supportingPawns & rank_bb(s)) ebonus += Value(r * 20); + else if (supportingPawns & rank_bb(s - pawn_push(Us))) ebonus += Value(r * 12); @@ -844,19 +953,180 @@ namespace { // 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 (file_of(s) == FILE_A || file_of(s) == FILE_H) { - if (pos.non_pawn_material(Them) <= KnightValueMidgame) + if (pos.non_pawn_material(Them) <= KnightValueMg) ebonus += ebonus / 4; - else if (pos.pieces(ROOK, QUEEN, Them)) + else if (pos.pieces(Them, ROOK, QUEEN)) ebonus -= ebonus / 4; } - bonus += make_score(mbonus, ebonus); + score += make_score(mbonus, ebonus); } while (b); // Add the scores to the middle game and endgame eval - return apply_weight(bonus, Weights[PassedPawns]); + return apply_weight(score, Weights[PassedPawns]); + } + + + // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite + // conservative and returns a winning score only when we are very sure that the pawn is winning. + + Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) { + + Bitboard b, b2, blockers, supporters, queeningPath, candidates; + Square s, blockSq, queeningSquare; + Color c, winnerSide, loserSide; + bool pathDefended, opposed; + int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d; + int pliesToQueen[] = { 256, 256 }; + + // Step 1. Hunt for unstoppable passed pawns. If we find at least one, + // record how many plies are required for promotion. + for (c = WHITE; c <= BLACK; c++) + { + // Skip if other side has non-pawn pieces + if (pos.non_pawn_material(~c)) + continue; + + b = ei.pi->passed_pawns(c); + + while (b) + { + s = pop_lsb(&b); + queeningSquare = relative_square(c, file_of(s) | RANK_8); + queeningPath = forward_bb(c, s); + + // Compute plies to queening and check direct advancement + movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2); + oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move()); + pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath); + + if (movesToGo >= oppMovesToGo && !pathDefended) + continue; + + // Opponent king cannot block because path is defended and position + // is not in check. So only friendly pieces can be blockers. + assert(!pos.in_check()); + assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c))); + + // Add moves needed to free the path from friendly pieces and retest condition + movesToGo += popcount(queeningPath & pos.pieces(c)); + + if (movesToGo >= oppMovesToGo && !pathDefended) + continue; + + pliesToGo = 2 * movesToGo - int(c == pos.side_to_move()); + pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo); + } + } + + // Step 2. If either side cannot promote at least three plies before the other side then situation + // becomes too complex and we give up. Otherwise we determine the possibly "winning side" + if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3) + return SCORE_ZERO; + + winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK); + loserSide = ~winnerSide; + + // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss? + b = candidates = pos.pieces(loserSide, PAWN); + + while (b) + { + s = pop_lsb(&b); + + // Compute plies from queening + queeningSquare = relative_square(loserSide, file_of(s) | RANK_8); + movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2); + pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move()); + + // Check if (without even considering any obstacles) we're too far away or doubled + if ( pliesToQueen[winnerSide] + 3 <= pliesToGo + || (forward_bb(loserSide, s) & pos.pieces(loserSide, PAWN))) + candidates ^= s; + } + + // If any candidate is already a passed pawn it _may_ promote in time. We give up. + if (candidates & ei.pi->passed_pawns(loserSide)) + return SCORE_ZERO; + + // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices + b = candidates; + + while (b) + { + s = pop_lsb(&b); + sacptg = blockersCount = 0; + minKingDist = kingptg = 256; + + // Compute plies from queening + queeningSquare = relative_square(loserSide, file_of(s) | RANK_8); + movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2); + pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move()); + + // Generate list of blocking pawns and supporters + supporters = adjacent_files_bb(file_of(s)) & candidates; + opposed = forward_bb(loserSide, s) & pos.pieces(winnerSide, PAWN); + blockers = passed_pawn_mask(loserSide, s) & pos.pieces(winnerSide, PAWN); + + assert(blockers); + + // How many plies does it take to remove all the blocking pawns? + while (blockers) + { + blockSq = pop_lsb(&blockers); + movesToGo = 256; + + // Check pawns that can give support to overcome obstacle, for instance + // black pawns: a4, b4 white: b2 then pawn in b4 is giving support. + if (!opposed) + { + b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide)); + + while (b2) // This while-loop could be replaced with LSB/MSB (depending on color) + { + d = square_distance(blockSq, pop_lsb(&b2)) - 2; + movesToGo = std::min(movesToGo, d); + } + } + + // Check pawns that can be sacrificed against the blocking pawn + b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s); + + while (b2) // This while-loop could be replaced with LSB/MSB (depending on color) + { + d = square_distance(blockSq, pop_lsb(&b2)) - 2; + movesToGo = std::min(movesToGo, d); + } + + // If obstacle can be destroyed with an immediate pawn exchange / sacrifice, + // it's not a real obstacle and we have nothing to add to pliesToGo. + if (movesToGo <= 0) + continue; + + // Plies needed to sacrifice against all the blocking pawns + sacptg += movesToGo * 2; + blockersCount++; + + // Plies needed for the king to capture all the blocking pawns + d = square_distance(pos.king_square(loserSide), blockSq); + minKingDist = std::min(minKingDist, d); + kingptg = (minKingDist + blockersCount) * 2; + } + + // Check if pawn sacrifice plan _may_ save the day + if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg) + return SCORE_ZERO; + + // Check if king capture plan _may_ save the day (contains some false positives) + if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg) + return SCORE_ZERO; + } + + // Winning pawn is unstoppable and will promote as first, return big score + Score score = make_score(0, (Value) 1280 - 32 * pliesToQueen[winnerSide]); + return winnerSide == WHITE ? score : -score; } @@ -866,7 +1136,7 @@ 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. The aim is to improve play on game opening. - template + template int evaluate_space(const Position& pos, EvalInfo& ei) { const Color Them = (Us == WHITE ? BLACK : WHITE); @@ -875,41 +1145,31 @@ namespace { // 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) + & ~pos.pieces(Us, PAWN) & ~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); + Bitboard behind = pos.pieces(Us, PAWN); 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); - } - - - // 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 popcount(safe) + popcount(behind & safe); } - // scale_by_game_phase() interpolates between a middle game and an endgame score, + // interpolate() 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, ScaleFactor sf) { + Value interpolate(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); - Value ev = Value((eg * int(sf)) / SCALE_FACTOR_NORMAL); - + int ev = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL; int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128; - return Value(result & ~(GrainSize - 1)); + return Value((result + GrainSize / 2) & ~(GrainSize - 1)); } @@ -919,36 +1179,48 @@ namespace { Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) { // Scale option value from 100 to 256 - int mg = get_option_value_int(mgOpt) * 256 / 100; - int eg = get_option_value_int(egOpt) * 256 / 100; + int mg = Options[mgOpt] * 256 / 100; + int eg = Options[egOpt] * 256 / 100; 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(). + // A couple of little helpers used by tracing code, to_cp() converts a value to + // a double in centipawns scale, trace_add() stores white and black scores. - void init_safety() { + double to_cp(Value v) { return double(v) / double(PawnValueMg); } - const Value MaxSlope = Value(30); - const Value Peak = Value(1280); - Value t[100]; + void trace_add(int idx, Score wScore, Score bScore) { - // First setup the base table - for (int i = 0; i < 100; i++) - { - t[i] = Value(int(0.4 * i * i)); + TracedScores[WHITE][idx] = wScore; + TracedScores[BLACK][idx] = bScore; + } - if (i > 0) - t[i] = Min(t[i], t[i - 1] + MaxSlope); - t[i] = Min(t[i], Peak); + // trace_row() is an helper function used by tracing code to register the + // values of a single evaluation term. + + void trace_row(const char* name, int idx) { + + Score wScore = TracedScores[WHITE][idx]; + Score bScore = TracedScores[BLACK][idx]; + + switch (idx) { + case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL: + TraceStream << std::setw(20) << name << " | --- --- | --- --- | " + << std::setw(6) << to_cp(mg_value(wScore)) << " " + << std::setw(6) << to_cp(eg_value(wScore)) << " \n"; + break; + default: + TraceStream << std::setw(20) << name << " | " << std::noshowpos + << std::setw(5) << to_cp(mg_value(wScore)) << " " + << std::setw(5) << to_cp(eg_value(wScore)) << " | " + << std::setw(5) << to_cp(mg_value(bScore)) << " " + << std::setw(5) << to_cp(eg_value(bScore)) << " | " + << std::showpos + << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " " + << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n"; } - - // Then apply the weights and get the final KingDangerTable[] array - for (Color c = WHITE; c <= BLACK; c++) - for (int i = 0; i < 100; i++) - KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]); } }