X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=62860b4a850d0ca42ed91a49369265068ced07e8;hp=85128c4f99b1091f11bf9c04a6e7334699f8d01d;hb=48c95706c857152c72c01e144875b88ce177a4ff;hpb=72b88e09e1e867d3878e8323d6e320241727f64d diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 85128c4f..62860b4a 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 Marco Costalba + Copyright (C) 2008-2009 Marco Costalba Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -25,6 +25,7 @@ #include #include +#include "bitcount.h" #include "evaluate.h" #include "material.h" #include "pawns.h" @@ -39,34 +40,33 @@ namespace { - const int Sign[2] = {1, -1}; + const int Sign[2] = { 1, -1 }; - // Evaluation grain size, must be a power of 2. + // Evaluation grain size, must be a power of 2 const int GrainSize = 4; - // Evaluation weights - int WeightMobilityMidgame = 0x100; - int WeightMobilityEndgame = 0x100; - int WeightPawnStructureMidgame = 0x100; - int WeightPawnStructureEndgame = 0x100; - int WeightPassedPawnsMidgame = 0x100; - int WeightPassedPawnsEndgame = 0x100; - int WeightKingSafety[2] = { 0x100, 0x100 }; + // Evaluation weights, initialized from UCI options + int WeightMobilityMidgame, WeightMobilityEndgame; + int WeightPawnStructureMidgame, WeightPawnStructureEndgame; + int WeightPassedPawnsMidgame, WeightPassedPawnsEndgame; + int WeightKingSafety[2]; int WeightSpace; - // Internal evaluation weights. These are applied on top of the evaluation - // weights read from UCI parameters. The purpose is to be able to change + // Internal evaluation weights. These are applied on top of the evaluation + // weights read from UCI parameters. The purpose is to be able to change // the evaluation weights while keeping the default values of the UCI // parameters at 100, which looks prettier. - const int WeightMobilityMidgameInternal = 0x100; - const int WeightMobilityEndgameInternal = 0x100; - const int WeightPawnStructureMidgameInternal = 0x100; - const int WeightPawnStructureEndgameInternal = 0x100; - const int WeightPassedPawnsMidgameInternal = 0x100; - const int WeightPassedPawnsEndgameInternal = 0x100; - const int WeightKingSafetyInternal = 0x110; - const int WeightKingOppSafetyInternal = 0x110; - const int WeightSpaceInternal = 0x30; + // + // Values modified by Joona Kiiski + const int WeightMobilityMidgameInternal = 0x0FA; + const int WeightMobilityEndgameInternal = 0x10A; + const int WeightPawnStructureMidgameInternal = 0x0EC; + const int WeightPawnStructureEndgameInternal = 0x0CD; + const int WeightPassedPawnsMidgameInternal = 0x108; + const int WeightPassedPawnsEndgameInternal = 0x109; + const int WeightKingSafetyInternal = 0x0F7; + const int WeightKingOppSafetyInternal = 0x101; + const int WeightSpaceInternal = 0x02F; // Visually better to define tables constants typedef Value V; @@ -84,7 +84,7 @@ namespace { }; // Bishop mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly pieces. X-ray attacks through + // of attacked squares not occupied by friendly pieces. X-ray attacks through // queens are also included. const Value MidgameBishopMobilityBonus[] = { // 0 1 2 3 4 5 6 7 @@ -101,7 +101,7 @@ namespace { }; // Rook mobility bonus in middle game and endgame, indexed by the number - // of attacked squares not occupied by friendly pieces. X-ray attacks through + // of attacked squares not occupied by friendly pieces. X-ray attacks through // queens and rooks are also included. const Value MidgameRookMobilityBonus[] = { // 0 1 2 3 4 5 6 7 @@ -167,46 +167,46 @@ namespace { V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0) // 8 }; - // Bonus for unstoppable passed pawns: + // Bonus for unstoppable passed pawns const Value UnstoppablePawnValue = Value(0x500); - // Rooks and queens on the 7th rank: - const Value MidgameRookOn7thBonus = Value(50); - const Value EndgameRookOn7thBonus = Value(100); - const Value MidgameQueenOn7thBonus = Value(25); - const Value EndgameQueenOn7thBonus = Value(50); + // Rooks and queens on the 7th rank + const Value MidgameRookOn7thBonus = Value(47); + const Value EndgameRookOn7thBonus = Value(98); + const Value MidgameQueenOn7thBonus = Value(27); + const Value EndgameQueenOn7thBonus = Value(54); - // Rooks on open files: - const Value RookOpenFileBonus = Value(40); - const Value RookHalfOpenFileBonus = Value(20); + // Rooks on open files + const Value RookOpenFileBonus = Value(43); + const Value RookHalfOpenFileBonus = Value(19); // Penalty for rooks trapped inside a friendly king which has lost the - // right to castle: + // right to castle. const Value TrappedRookPenalty = Value(180); // Penalty for a bishop on a7/h7 (a2/h2 for black) which is trapped by - // enemy pawns: + // enemy pawns. const Value TrappedBishopA7H7Penalty = Value(300); - // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black): + // Bitboard masks for detecting trapped bishops on a7/h7 (a2/h2 for black) const Bitboard MaskA7H7[2] = { ((1ULL << SQ_A7) | (1ULL << SQ_H7)), ((1ULL << SQ_A2) | (1ULL << SQ_H2)) }; // 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 + // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only // happen in Chess960 games. const Value TrappedBishopA1H1Penalty = Value(100); - // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black): + // Bitboard masks for detecting trapped bishops on a1/h1 (a8/h8 for black) const Bitboard MaskA1H1[2] = { ((1ULL << SQ_A1) | (1ULL << SQ_H1)), ((1ULL << SQ_A8) | (1ULL << SQ_H8)) }; // The SpaceMask[color] contains area of the board which is consdered by - // the space evaluation. In the middle game, each side is given a bonus + // the space evaluation. In the middle game, each side is given a bonus // based on how many squares inside this area are safe and available for // friendly minor pieces. const Bitboard SpaceMask[2] = { @@ -218,30 +218,26 @@ namespace { (1ULL< + template + Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID); + + template void evaluate_pieces(const Position& p, Color us, EvalInfo& ei); template<> - void evaluate_pieces(const Position& p, Color us, EvalInfo &ei); + void evaluate_pieces(const Position& p, Color us, EvalInfo &ei); void evaluate_passed_pawns(const Position &pos, EvalInfo &ei); void evaluate_trapped_bishop_a7h7(const Position &pos, Square s, Color us, @@ -288,8 +287,6 @@ namespace { inline Value apply_weight(Value v, int w); Value scale_by_game_phase(Value mv, Value ev, Phase ph, const ScaleFactor sf[]); - int count_1s_8bit(Bitboard b); - int compute_weight(int uciWeight, int internalWeight); int weight_option(const std::string& opt, int weight); void init_safety(); @@ -301,11 +298,19 @@ namespace { //// Functions //// -/// evaluate() is the main evaluation function. It always computes two +/// 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, int threadID) { + + return CpuHasPOPCNT ? do_evaluate(pos, ei, threadID) + : do_evaluate(pos, ei, threadID); +} + +namespace { -Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { +template +Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) { assert(pos.is_ok()); assert(threadID >= 0 && threadID < THREAD_MAX); @@ -346,16 +351,16 @@ Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { // Initialize pawn attack bitboards for both sides ei.attackedBy[WHITE][PAWN] = ((pos.pawns(WHITE) << 9) & ~FileABB) | ((pos.pawns(WHITE) << 7) & ~FileHBB); ei.attackedBy[BLACK][PAWN] = ((pos.pawns(BLACK) >> 7) & ~FileABB) | ((pos.pawns(BLACK) >> 9) & ~FileHBB); - ei.kingAttackersCount[WHITE] = count_1s_max_15(ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING])/2; - ei.kingAttackersCount[BLACK] = count_1s_max_15(ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING])/2; + ei.kingAttackersCount[WHITE] = count_1s_max_15(ei.attackedBy[WHITE][PAWN] & ei.attackedBy[BLACK][KING])/2; + ei.kingAttackersCount[BLACK] = count_1s_max_15(ei.attackedBy[BLACK][PAWN] & ei.attackedBy[WHITE][KING])/2; // Evaluate pieces for (Color c = WHITE; c <= BLACK; c++) { - evaluate_pieces(pos, c, ei); - evaluate_pieces(pos, c, ei); - evaluate_pieces(pos, c, ei); - evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); // Sum up all attacked squares ei.attackedBy[c][0] = ei.attackedBy[c][PAWN] | ei.attackedBy[c][KNIGHT] @@ -367,7 +372,7 @@ Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { // because we need complete attack information for all pieces when computing // the king safety evaluation. for (Color c = WHITE; c <= BLACK; c++) - evaluate_pieces(pos, c, ei); + evaluate_pieces(pos, c, ei); // Evaluate passed pawns. We evaluate passed pawns for both sides at once, // because we need to know which side promotes first in positions where @@ -443,6 +448,7 @@ Value evaluate(const Position &pos, EvalInfo &ei, int threadID) { return (ei.mateThreat[stm] == MOVE_NONE ? v : 8 * QueenValueMidgame - v); } +} // namespace /// quick_evaluate() does a very approximate evaluation of the current position. /// It currently considers only material and piece square table scores. Perhaps @@ -487,7 +493,10 @@ void init_eval(int threads) { } for (Bitboard b = 0ULL; b < 256ULL; b++) - BitCount8Bit[b] = count_1s(b); + { + assert(count_1s(b) == int(uint8_t(count_1s(b)))); + BitCount8Bit[b] = (uint8_t)count_1s(b); + } } @@ -499,6 +508,8 @@ void quit_eval() { { delete PawnTable[i]; delete MaterialTable[i]; + PawnTable[i] = NULL; + MaterialTable[i] = NULL; } } @@ -527,76 +538,76 @@ void read_weights(Color us) { namespace { - // evaluate_common() computes terms common to all pieces attack + // evaluate_mobility() computes mobility and attacks for every piece - template - int evaluate_common(const Position& p, const Bitboard& b, Color us, EvalInfo& ei, Square s = SQ_NONE) { + template + int evaluate_mobility(const Position& p, const Bitboard& b, Color us, Color them, EvalInfo& ei) { static const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight }; static const Value* MgBonus[] = { 0, 0, MidgameKnightMobilityBonus, MidgameBishopMobilityBonus, MidgameRookMobilityBonus, MidgameQueenMobilityBonus }; static const Value* EgBonus[] = { 0, 0, EndgameKnightMobilityBonus, EndgameBishopMobilityBonus, EndgameRookMobilityBonus, EndgameQueenMobilityBonus }; - static const Value* OutpostBonus[] = { 0, 0, KnightOutpostBonus, BishopOutpostBonus, 0, 0 }; - - Color them = opposite_color(us); // Update attack info ei.attackedBy[us][Piece] |= b; - // King attack + // King attacks if (b & ei.kingZone[us]) { ei.kingAttackersCount[us]++; ei.kingAttackersWeight[us] += AttackWeight[Piece]; Bitboard bb = (b & ei.attackedBy[them][KING]); if (bb) - ei.kingAdjacentZoneAttacksCount[us] += count_1s_max_15(bb); + ei.kingAdjacentZoneAttacksCount[us] += count_1s_max_15(bb); } // Remove squares protected by enemy pawns Bitboard bb = (b & ~ei.attackedBy[them][PAWN]); // Mobility - int mob = (Piece != QUEEN ? count_1s_max_15(bb & ~p.pieces_of_color(us)) - : count_1s(bb & ~p.pieces_of_color(us))); + int mob = (Piece != QUEEN ? count_1s_max_15(bb & ~p.pieces_of_color(us)) + : count_1s(bb & ~p.pieces_of_color(us))); ei.mgMobility += Sign[us] * MgBonus[Piece][mob]; ei.egMobility += Sign[us] * EgBonus[Piece][mob]; + return mob; + } - // Bishop and Knight outposts - if ( (Piece != BISHOP && Piece != KNIGHT) // compile time condition - || !p.square_is_weak(s, them)) - return mob; + + // evaluate_outposts() evaluates bishop and knight outposts squares + + template + void evaluate_outposts(const Position& p, Color us, Color them, EvalInfo& ei, Square s) { // Initial bonus based on square - Value v, bonus; - v = bonus = OutpostBonus[Piece][relative_square(us, s)]; + Value bonus = (Piece == BISHOP ? BishopOutpostBonus[relative_square(us, s)] + : KnightOutpostBonus[relative_square(us, s)]); // Increase bonus if supported by pawn, especially if the opponent has // no minor piece which can exchange the outpost piece - if (v && (p.pawn_attacks(them, s) & p.pawns(us))) + if (bonus && (p.pawn_attacks(them, s) & p.pawns(us))) { - bonus += v / 2; - if ( p.piece_count(them, KNIGHT) == 0 + if ( p.knights(them) == EmptyBoardBB && (SquaresByColorBB[square_color(s)] & p.bishops(them)) == EmptyBoardBB) - bonus += v; + bonus += bonus + bonus / 2; + else + bonus += bonus / 2; } ei.mgValue += Sign[us] * bonus; ei.egValue += Sign[us] * bonus; - return mob; } // evaluate_pieces<>() assigns bonuses and penalties to the pieces of a given // color. - template + template void evaluate_pieces(const Position& pos, Color us, EvalInfo& ei) { Bitboard b; Square s, ksq; - Color them; int mob; File f; + Color them = opposite_color(us); for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++) { @@ -608,9 +619,15 @@ namespace { b = bishop_attacks_bb(s, pos.occupied_squares() & ~pos.queens(us)); else if (Piece == ROOK) b = rook_attacks_bb(s, pos.occupied_squares() & ~pos.rooks_and_queens(us)); + else + assert(false); + + // Attacks and mobility + mob = evaluate_mobility(pos, b, us, them, ei); - // Attacks, mobility and outposts - mob = evaluate_common(pos, b, us, ei, s); + // Bishop and knight outposts squares + if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, them)) + evaluate_outposts(pos, us, them, ei, s); // Special patterns: trapped bishops on a7/h7/a2/h2 // and trapped bishops on a1/h1/a8/h8 in Chess960. @@ -623,63 +640,61 @@ namespace { evaluate_trapped_bishop_a1h1(pos, s, us, ei); } - if (Piece != ROOK && Piece != QUEEN) - continue; - - // Queen or rook on 7th rank - them = opposite_color(us); - - if ( relative_rank(us, s) == RANK_7 - && relative_rank(us, pos.king_square(them)) == RANK_8) + if (Piece == ROOK || Piece == QUEEN) { - ei.mgValue += Sign[us] * (Piece == ROOK ? MidgameRookOn7thBonus : MidgameQueenOn7thBonus); - ei.egValue += Sign[us] * (Piece == ROOK ? EndgameRookOn7thBonus : EndgameQueenOn7thBonus); + // Queen or rook on 7th rank + if ( relative_rank(us, s) == RANK_7 + && relative_rank(us, pos.king_square(them)) == RANK_8) + { + ei.mgValue += Sign[us] * (Piece == ROOK ? MidgameRookOn7thBonus : MidgameQueenOn7thBonus); + ei.egValue += Sign[us] * (Piece == ROOK ? EndgameRookOn7thBonus : EndgameQueenOn7thBonus); + } } // Special extra evaluation for rooks - if (Piece != ROOK) - continue; - - // Open and half-open files - f = square_file(s); - if (ei.pi->file_is_half_open(us, f)) + if (Piece == ROOK) { - if (ei.pi->file_is_half_open(them, f)) + // Open and half-open files + f = square_file(s); + if (ei.pi->file_is_half_open(us, f)) { - ei.mgValue += Sign[us] * RookOpenFileBonus; - ei.egValue += Sign[us] * RookOpenFileBonus; - } - else - { - ei.mgValue += Sign[us] * RookHalfOpenFileBonus; - ei.egValue += Sign[us] * RookHalfOpenFileBonus; + if (ei.pi->file_is_half_open(them, f)) + { + ei.mgValue += Sign[us] * RookOpenFileBonus; + ei.egValue += Sign[us] * RookOpenFileBonus; + } + else + { + ei.mgValue += Sign[us] * RookHalfOpenFileBonus; + ei.egValue += Sign[us] * RookHalfOpenFileBonus; + } } - } - // Penalize rooks which are trapped inside a king. Penalize more if - // king has lost right to castle. - if (mob > 6 || ei.pi->file_is_half_open(us, f)) - continue; + // Penalize rooks which are trapped inside a king. Penalize more if + // king has lost right to castle. + if (mob > 6 || ei.pi->file_is_half_open(us, f)) + continue; - ksq = pos.king_square(us); + 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))) - { - // 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.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[us] * (TrappedRookPenalty - mob * 16); - } - 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))) - { - // 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.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) - : Sign[us] * (TrappedRookPenalty - mob * 16); + if ( square_file(ksq) >= FILE_E + && square_file(s) > square_file(ksq) + && (relative_rank(us, ksq) == RANK_1 || square_rank(ksq) == square_rank(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))) + ei.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) + : Sign[us] * (TrappedRookPenalty - mob * 16); + } + 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))) + { + // 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.mgValue -= pos.can_castle(us)? Sign[us] * ((TrappedRookPenalty - mob * 16) / 2) + : Sign[us] * (TrappedRookPenalty - mob * 16); + } } } } @@ -693,7 +708,7 @@ namespace { // color. template<> - void evaluate_pieces(const Position& p, Color us, EvalInfo& ei) { + void evaluate_pieces(const Position& p, Color us, EvalInfo& ei) { int shelter = 0, sign = Sign[us]; Square s = p.king_square(us); @@ -701,15 +716,23 @@ namespace { // King shelter if (relative_rank(us, s) <= RANK_4) { - Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s); - Rank r = square_rank(s); - for (int i = 1; i < 4; i++) - shelter += count_1s_8bit(shiftRowsDown(pawns, r+i*sign)) * (128>>i); - + // Shelter cache lookup + shelter = ei.pi->kingShelter(us, s); + if (shelter == -1) + { + shelter = 0; + Bitboard pawns = p.pawns(us) & this_and_neighboring_files_bb(s); + Rank r = square_rank(s); + for (int i = 1; i < 4; i++) + shelter += BitCount8Bit[shiftRowsDown(pawns, r+i*sign) & 0xFF] * (128 >> i); + + // Cache shelter value in pawn info + ei.pi->setKingShelter(us, s, shelter); + } ei.mgValue += sign * Value(shelter); } - // King safety. This is quite complicated, and is almost certainly far + // King safety. This is quite complicated, and is almost certainly far // from optimally tuned. Color them = opposite_color(us); @@ -776,7 +799,7 @@ namespace { if ( bit_is_set(p.piece_attacks(from), to) && !bit_is_set(p.pinned_pieces(them), from) && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.rooks_and_queens(us)) - && !(rook_attacks_bb(to, occ & ClearMaskBB[from]) & p.rooks_and_queens(us))) + && !(bishop_attacks_bb(to, occ & ClearMaskBB[from]) & p.bishops_and_queens(us))) ei.mateThreat[them] = make_move(from, to); } @@ -914,29 +937,23 @@ namespace { && (squares_behind(us, s) & pos.rooks_and_queens(them))) b3 = b2; - if ((b2 & pos.pieces_of_color(them)) == EmptyBoardBB) - { - // There are no enemy pieces in the pawn's path! Are any of the - // squares in the pawn's path attacked by the enemy? - if (b3 == EmptyBoardBB) - // No enemy attacks, huge bonus! - ebonus += Value(tr * (b2 == b4 ? 17 : 15)); - else - // OK, there are enemy attacks. Are those squares which are - // attacked by the enemy also attacked by us? If yes, big bonus - // (but smaller than when there are no enemy attacks), if no, - // somewhat smaller bonus. - ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); - } + // Squares attacked or occupied by enemy pieces + b3 |= (b2 & pos.pieces_of_color(them)); + + // There are no enemy pawns in the pawn's path + assert((b2 & pos.pieces_of_color_and_type(them, PAWN)) == EmptyBoardBB); + + // Are any of the squares in the pawn's path attacked or occupied by the enemy? + if (b3 == EmptyBoardBB) + // No enemy attacks or pieces, huge bonus! + ebonus += Value(tr * (b2 == b4 ? 17 : 15)); else - { - // There are some enemy pieces in the pawn's path. While this is - // sad, we still assign a moderate bonus if all squares in the path - // which are either occupied by or attacked by enemy pieces are - // also attacked by us. - if (((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB) - ebonus += Value(tr * 6); - } + // OK, there are enemy attacks or pieces (but not pawns). Are those + // squares which are attacked by the enemy also attacked by us? + // If yes, big bonus (but smaller than when there are no enemy attacks), + // if no, somewhat smaller bonus. + ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); + // At last, add a small bonus when there are no *friendly* pieces // in the pawn's path. if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB) @@ -976,7 +993,7 @@ namespace { } } } - // Rook pawns are a special case: They are sometimes worse, and + // Rook pawns are a special case: They are sometimes worse, and // sometimes better than other passed pawns. It is difficult to find // good rules for determining whether they are good or bad. For now, // we try the following: Increase the value for rook pawns if the @@ -984,10 +1001,10 @@ namespace { // value if the other side has a rook or queen. if (square_file(s) == FILE_A || square_file(s) == FILE_H) { - if( pos.non_pawn_material(them) <= KnightValueMidgame - && pos.piece_count(them, KNIGHT) <= 1) + if ( pos.non_pawn_material(them) <= KnightValueMidgame + && pos.piece_count(them, KNIGHT) <= 1) ebonus += ebonus / 4; - else if(pos.rooks_and_queens(them)) + else if (pos.rooks_and_queens(them)) ebonus -= ebonus / 4; } @@ -999,9 +1016,9 @@ namespace { // Does either side have an unstoppable passed pawn? if (hasUnstoppable[WHITE] && !hasUnstoppable[BLACK]) - ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); + ei.egValue += UnstoppablePawnValue - Value(0x40 * movesToGo[WHITE]); else if (hasUnstoppable[BLACK] && !hasUnstoppable[WHITE]) - ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); + ei.egValue -= UnstoppablePawnValue - Value(0x40 * movesToGo[BLACK]); else if (hasUnstoppable[BLACK] && hasUnstoppable[WHITE]) { // Both sides have unstoppable pawns! Try to find out who queens @@ -1158,15 +1175,6 @@ namespace { } - // count_1s_8bit() counts the number of nonzero bits in the 8 least - // significant bits of a Bitboard. This function is used by the king - // shield evaluation. - - int count_1s_8bit(Bitboard b) { - return int(BitCount8Bit[b & 0xFF]); - } - - // compute_weight() computes the value of an evaluation weight, by combining // an UCI-configurable weight with an internal weight.