X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=8bdf193653dec007ed41a8df7a40768dbb0511ad;hp=664f3e859f32ea3e77fa352fa576fba98137000f;hb=75acd52415209296fad778db41209170734647dc;hpb=2a2353aac65d6f7263081dc373c768c8717602db diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 664f3e85..8bdf1936 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -23,6 +23,9 @@ //// #include +#include +#include +#include #include "bitcount.h" #include "evaluate.h" @@ -128,18 +131,14 @@ 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 @@ -172,6 +171,11 @@ namespace { // 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); + // 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 @@ -194,9 +198,10 @@ 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; @@ -217,22 +222,27 @@ 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 TracedTerms[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 - Value do_evaluate(const Position& pos, Value margins[]); + template + Value do_evaluate(const Position& pos, Value& margin); 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 + template Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]); template @@ -244,71 +254,68 @@ namespace { 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, const ScaleFactor sf[]); + template + Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei); + + inline 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(); } -//// -//// Functions -//// - - -/// Prefetches in pawn hash tables - -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, Value margins[]) { +Value evaluate(const Position& pos, Value& margin) { - return CpuHasPOPCNT ? do_evaluate(pos, margins) - : do_evaluate(pos, margins); + return CpuHasPOPCNT ? do_evaluate(pos, margin) + : do_evaluate(pos, margin); } namespace { -template -Value do_evaluate(const Position& pos, Value margins[]) { +double to_cp(Value v) { return double(v) / double(PawnValueMidgame); } + +void trace_add(int idx, Score term_w, Score term_b = Score(0)) { + + TracedTerms[WHITE][idx] = term_w; + TracedTerms[BLACK][idx] = term_b; +} + +template +Value do_evaluate(const Position& pos, Value& margin) { EvalInfo ei; - ScaleFactor factor[2]; + Value margins[2]; Score mobilityWhite, mobilityBlack; assert(pos.is_ok()); assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS); - assert(!pos.is_check()); + assert(!pos.in_check()); // Initialize value by reading the incrementally updated scores included // in the position object (material + piece square tables). Score bonus = pos.value(); - // margins[color] is the uncertainty estimation of position's evaluation - // and typically is used by the search for pruning decisions. + // 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; // Probe the material hash table - MaterialInfo* mi = MaterialTable[pos.thread()]->get_material_info(pos); + MaterialInfo* mi = Threads[pos.thread()].materialTable.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 (mi->specialized_eval_exists()) + { + margin = VALUE_ZERO; return mi->evaluate(pos); - - // After get_material_info() call that modifies them - 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.pi = Threads[pos.thread()].pawnTable.get_pawn_info(pos); bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]); // Initialize attack and king safety bitboards @@ -316,15 +323,15 @@ Value do_evaluate(const Position& pos, Value margins[]) { init_eval_info(pos, ei); // Evaluate pieces and mobility - bonus += evaluate_pieces_of_color(pos, ei, mobilityWhite) - - evaluate_pieces_of_color(pos, ei, mobilityBlack); + bonus += evaluate_pieces_of_color(pos, ei, mobilityWhite) + - evaluate_pieces_of_color(pos, ei, mobilityBlack); bonus += 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, margins) - - evaluate_king(pos, ei, margins); + bonus += 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) @@ -334,39 +341,33 @@ Value do_evaluate(const Position& pos, Value margins[]) { bonus += 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)) + bonus += evaluate_unstoppable_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) - - bonus += 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) - - bonus += make_score(ei.pi->kingside_storm_value(WHITE) - ei.pi->queenside_storm_value(BLACK), 0); + int s_w = evaluate_space(pos, ei); + int s_b = evaluate_space(pos, ei); + bonus += apply_weight(make_score((s_w - s_b) * mi->space_weight(), 0), Weights[Space]); - // Evaluate space for both sides - if (mi->space_weight() > 0) - { - int s = evaluate_space(pos, ei) - evaluate_space(pos, ei); - bonus += apply_weight(make_score(s * mi->space_weight(), 0), Weights[Space]); - } + if (Trace) + trace_add(SPACE, apply_weight(make_score(s_w * mi->space_weight(), make_score(0, 0)), Weights[Space]), + apply_weight(make_score(s_b * mi->space_weight(), make_score(0, 0)), Weights[Space])); } + // Scale winning side if position is more drawish that what it appears + ScaleFactor sf = eg_value(bonus) > VALUE_DRAW ? 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(bonus) > VALUE_ZERO) - || (factor[BLACK] == SCALE_FACTOR_NORMAL && eg_value(bonus) < 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) @@ -380,57 +381,40 @@ Value do_evaluate(const Position& pos, Value margins[]) { // 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 - Value v = scale_by_game_phase(bonus, phase, factor); - return pos.side_to_move() == WHITE ? v : -v; -} + margin = margins[pos.side_to_move()]; + Value v = scale_by_game_phase(bonus, phase, sf); -} // namespace - - -/// init_eval() initializes various tables used by the evaluation function - -void init_eval(int threads) { - - assert(threads <= MAX_THREADS); - - for (int i = 0; i < MAX_THREADS; i++) + 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.value()); + trace_add(IMBALANCE, mi->material_value()); + trace_add(PAWN, apply_weight(ei.pi->pawns_value(), Weights[PawnStructure])); + 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)); + trace_add(TOTAL, bonus); + TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE]) + << ", Black: " << to_cp(margins[BLACK]) + << "\nScaling: " << std::noshowpos + << std::setw(6) << 100.0 * phase/128.0 << "% MG, " + << std::setw(6) << 100.0 * (1.0 - 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); + return pos.side_to_move() == WHITE ? v : -v; } +} // namespace + /// read_weights() reads evaluation weights from the corresponding UCI parameters -void read_weights(Color us) { +void read_evaluation_uci_options(Color us) { // King safety is asymmetrical. Our king danger level is weighted by // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness". @@ -446,7 +430,7 @@ void read_weights(Color us) { // 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")) + if (Options["UCI_AnalyseMode"].value()) Weights[kingDangerUs] = Weights[kingDangerThem] = (Weights[kingDangerUs] + Weights[kingDangerThem]) / 2; init_safety(); @@ -461,14 +445,22 @@ namespace { template 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 : EmptyBoardBB; - ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = EmptyBoardBB; + + // 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; } @@ -500,8 +492,8 @@ namespace { // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given color - template - Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard no_mob_area) { + template + Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score& mobility, Bitboard mobilityArea) { Bitboard b; Square s, ksq; @@ -509,6 +501,8 @@ namespace { File f; 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); @@ -536,12 +530,12 @@ 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]; @@ -562,6 +556,27 @@ namespace { bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus); } + // Special extra evaluation for bishops + if (Piece == BISHOP && pos.is_chess960()) + { + // 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) + (square_file(s) == FILE_A ? DELTA_E : DELTA_W); + if (pos.piece_on(s + d) == make_piece(Us, PAWN)) + { + if (!pos.square_is_empty(s + d + pawn_push(Us))) + bonus -= 2*TrappedBishopA1H1Penalty; + else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN)) + bonus -= TrappedBishopA1H1Penalty; + else + bonus -= TrappedBishopA1H1Penalty / 2; + } + } + } + // Special extra evaluation for rooks if (Piece == ROOK) { @@ -602,6 +617,10 @@ namespace { } } } + + if (Trace) + TracedTerms[Us][Piece] = bonus; + return bonus; } @@ -642,7 +661,7 @@ namespace { // 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); @@ -650,12 +669,12 @@ namespace { 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)); - 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); + 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] @@ -667,9 +686,10 @@ namespace { // evaluate_king<>() assigns bonuses and penalties to a king of a given color - template + template Score evaluate_king(const Position& pos, EvalInfo& ei, Value margins[]) { + const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; const Color Them = (Us == WHITE ? BLACK : WHITE); Bitboard undefended, b, b1, b2, safe; @@ -681,9 +701,7 @@ namespace { // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. - if ( ei.kingAttackersCount[Them] >= 2 - && pos.non_pawn_material(Them) >= QueenValueMidgame + RookValueMidgame - && pos.piece_count(Them, QUEEN) >= 1 + if ( ei.kingAttackersCount[Them] >= 2 && ei.kingAdjacentZoneAttacksCount[Them]) { // Find the attacked squares around the king which has no defenders @@ -699,7 +717,7 @@ 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, ksq)) / 32; @@ -713,7 +731,25 @@ namespace { | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]); if (b) attackUnits += QueenContactCheckBonus - * count_1s_max_15(b) + * 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); } @@ -726,22 +762,22 @@ 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)); @@ -754,6 +790,10 @@ namespace { bonus -= KingDangerTable[Us][attackUnits]; margins[Us] += mg_value(KingDangerTable[Us][attackUnits]); } + + if (Trace) + TracedTerms[Us][KING] = bonus; + return bonus; } @@ -802,8 +842,8 @@ namespace { // 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 ( (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them)) + && (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s))) unsafeSquares = squaresToQueen; else unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces_of_color(Them)); @@ -856,6 +896,173 @@ namespace { } + // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides + + template + Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) { + + const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15; + + Bitboard b1, b2, queeningPath, candidates, supBB, sacBB; + Square s1, s2, queeningSquare, supSq, sacSq; + Color c, winnerSide, loserSide; + bool pathDefended, opposed; + int pliesToGo, movesToGo, oppMovesToGo; + int pliesToQueen[] = { 256, 256 }; + + // Step 1. Hunt for unstoppable 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(opposite_color(c))) + continue; + + b1 = ei.pi->passed_pawns(c); + + while (b1) + { + s1 = pop_1st_bit(&b1); + queeningSquare = relative_square(c, make_square(square_file(s1), RANK_8)); + queeningPath = squares_in_front_of(c, s1); + + // Compute plies from queening and check direct advancement + movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(c, s1) == RANK_2); + oppMovesToGo = square_distance(pos.king_square(opposite_color(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.occupied_squares() == queeningPath & pos.pieces_of_color(c)); + + // Add moves needed to free the path from friendly pieces and retest condition + movesToGo += count_1s(queeningPath & pos.pieces_of_color(c)); + + if (movesToGo >= oppMovesToGo && !pathDefended) + continue; + + pliesToGo = 2 * movesToGo - int(c == pos.side_to_move()); + + if (pliesToGo < pliesToQueen[c]) + 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 = opposite_color(winnerSide); + + // Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss? + // We collect the potential candidates in potentialBB. + b1 = candidates = pos.pieces(PAWN, loserSide); + + while (b1) + { + s1 = pop_1st_bit(&b1); + + // Compute plies from queening + queeningSquare = relative_square(loserSide, make_square(square_file(s1), RANK_8)); + movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(loserSide, s1) == 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 + || (squares_in_front_of(loserSide, s1) & pos.pieces(PAWN, loserSide))) + clear_bit(&candidates, s1); + } + + // 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 sacrifices + b1 = candidates; + + while (b1) + { + s1 = pop_1st_bit(&b1); + + // Compute plies from queening + queeningSquare = relative_square(loserSide, make_square(square_file(s1), RANK_8)); + movesToGo = rank_distance(s1, queeningSquare) - int(relative_rank(loserSide, s1) == RANK_2); + pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move()); + + // Generate list of obstacles + opposed = squares_in_front_of(loserSide, s1) & pos.pieces(PAWN, winnerSide); + b2 = passed_pawn_mask(loserSide, s1) & pos.pieces(PAWN, winnerSide); + + assert(b2); + + // How many plies does it take to remove all the obstacles? + int sacptg = 0; + int realObsCount = 0; + int minKingDist = 256; + int kingptg = 256; + + while (b2) + { + s2 = pop_1st_bit(&b2); + 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) + { + supBB = in_front_bb(winnerSide, s2 + pawn_push(winnerSide)) & neighboring_files_bb(s1) & candidates; + + while (supBB) // This while-loop could be replaced with supSq = LSB/MSB(supBB) (depending on color) + { + supSq = pop_1st_bit(&supBB); + movesToGo = Min(movesToGo, square_distance(s2, supSq) - 2); + } + } + + // Check pawns that can be sacrificed + sacBB = passed_pawn_mask(winnerSide, s2) & neighboring_files_bb(s2) & candidates & ~(1ULL << s1); + + while (sacBB) // This while-loop could be replaced with sacSq = LSB/MSB(sacBB) (depending on color) + { + sacSq = pop_1st_bit(&sacBB); + movesToGo = Min(movesToGo, square_distance(s2, sacSq) - 2); + } + + // Good, obstacle can be destroyed with an immediate pawn sacrifice, + // it's not a real obstacle and we have nothing to add to pliesToGo. + if (movesToGo <= 0) + continue; + + // Plies needed to sacrifice the pawn + sacptg += movesToGo * 2; + realObsCount++; + + // Plies needed for the king to capture opposing pawn + minKingDist = Min(minKingDist, square_distance(pos.king_square(loserSide), s2)); + kingptg = (minKingDist + realObsCount) * 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) 0x500 - 0x20 * pliesToQueen[winnerSide]); + return winnerSide == WHITE ? score : -score; + } + + // evaluate_space() computes the space evaluation for a given side. The // space evaluation is a simple bonus based on the number of safe squares // available for minor pieces on the central four files on ranks 2--4. Safe @@ -865,6 +1072,7 @@ namespace { 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 @@ -880,7 +1088,7 @@ 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); } @@ -895,18 +1103,15 @@ namespace { // 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); - + 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)); } @@ -916,8 +1121,8 @@ 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].value() * 256 / 100; + int eg = Options[egOpt].value() * 256 / 100; return apply_weight(make_score(mg, eg), internalWeight); } @@ -948,4 +1153,75 @@ namespace { for (int i = 0; i < 100; i++) KingDangerTable[c][i] = apply_weight(make_score(t[i], 0), Weights[KingDangerUs + c]); } + + + // 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 term_w = TracedTerms[WHITE][idx]; + Score term_b = TracedTerms[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(term_w)) << " " + << std::setw(6) << to_cp(eg_value(term_w)) << " \n"; + break; + default: + TraceStream << std::setw(20) << name << " | " << std::noshowpos + << std::setw(5) << to_cp(mg_value(term_w)) << " " + << std::setw(5) << to_cp(eg_value(term_w)) << " | " + << std::setw(5) << to_cp(mg_value(term_b)) << " " + << std::setw(5) << to_cp(eg_value(term_b)) << " | " + << std::showpos + << std::setw(6) << to_cp(mg_value(term_w - term_b)) << " " + << std::setw(6) << to_cp(eg_value(term_w - term_b)) << " \n"; + } + } +} + + +/// trace_evaluate() 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_evaluate(const Position& pos) { + + Value margin; + std::string totals; + + TraceStream.str(""); + TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2); + memset(TracedTerms, 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(); }