X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=cf1019ac07cd3646c036499353556d50fce956e1;hp=0098b39c949cc30fa6ddc1ef21196e209d7983c2;hb=c2d42ea8339b49e52a116e488214a14fda09d413;hpb=f200f3ccd2281deadecb6279fac59b16dea622d5 diff --git a/src/material.cpp b/src/material.cpp index 0098b39c..cf1019ac 100644 --- a/src/material.cpp +++ b/src/material.cpp @@ -17,30 +17,23 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include #include -#include +#include #include "material.h" using namespace std; - -//// -//// Local definitions -//// - namespace { // Values modified by Joona Kiiski const Value MidgameLimit = Value(15581); const Value EndgameLimit = Value(3998); + // Scale factors used when one side has no more pawns + const int NoPawnsSF[4] = { 6, 12, 32 }; + // Polynomial material balance parameters const Value RedundantQueenPenalty = Value(320); const Value RedundantRookPenalty = Value(554); @@ -55,19 +48,15 @@ namespace { { 41, 41, 41, 41, 41, 41 }, { 37, 41, 41, 41, 41, 41 }, { 10, 62, 41, 41, 41, 41 }, { 57, 64, 39, 41, 41, 41 }, { 50, 40, 23, -22, 41, 41 }, { 106, 101, 3, 151, 171, 41 } }; - typedef EndgameEvaluationFunctionBase EF; - typedef EndgameScalingFunctionBase SF; - typedef map EFMap; - typedef map SFMap; - // Endgame evaluation and scaling functions accessed direcly and not through // the function maps because correspond to more then one material hash key. - EvaluationFunction EvaluateKmmKm[] = { EvaluationFunction(WHITE), EvaluationFunction(BLACK) }; - EvaluationFunction EvaluateKXK[] = { EvaluationFunction(WHITE), EvaluationFunction(BLACK) }; - ScalingFunction ScaleKBPsK[] = { ScalingFunction(WHITE), ScalingFunction(BLACK) }; - ScalingFunction ScaleKQKRPs[] = { ScalingFunction(WHITE), ScalingFunction(BLACK) }; - ScalingFunction ScaleKPsK[] = { ScalingFunction(WHITE), ScalingFunction(BLACK) }; - ScalingFunction ScaleKPKP[] = { ScalingFunction(WHITE), ScalingFunction(BLACK) }; + Endgame EvaluateKmmKm[] = { Endgame(WHITE), Endgame(BLACK) }; + Endgame EvaluateKXK[] = { Endgame(WHITE), Endgame(BLACK) }; + + Endgame ScaleKBPsK[] = { Endgame(WHITE), Endgame(BLACK) }; + Endgame ScaleKQKRPs[] = { Endgame(WHITE), Endgame(BLACK) }; + Endgame ScaleKPsK[] = { Endgame(WHITE), Endgame(BLACK) }; + Endgame ScaleKPKP[] = { Endgame(WHITE), Endgame(BLACK) }; // Helper templates used to detect a given material distribution template bool is_KXK(const Position& pos) { @@ -77,7 +66,7 @@ namespace { && pos.non_pawn_material(Us) >= RookValueMidgame; } - template bool is_KBPsK(const Position& pos) { + template bool is_KBPsKs(const Position& pos) { return pos.non_pawn_material(Us) == BishopValueMidgame && pos.piece_count(Us, BISHOP) == 1 && pos.piece_count(Us, PAWN) >= 1; @@ -91,98 +80,26 @@ namespace { && pos.piece_count(Them, ROOK) == 1 && pos.piece_count(Them, PAWN) >= 1; } -} - - -//// -//// Classes -//// - -/// EndgameFunctions class stores endgame evaluation and scaling functions -/// in two std::map. Because STL library is not guaranteed to be thread -/// safe even for read access, the maps, although with identical content, -/// are replicated for each thread. This is faster then using locks. - -class EndgameFunctions { -public: - EndgameFunctions(); - ~EndgameFunctions(); - template T* get(Key key) const; - -private: - template void add(const string& keyCode); - - static Key buildKey(const string& keyCode); - static const string swapColors(const string& keyCode); - - // Here we store two maps, for evaluate and scaling functions... - pair maps; - - // ...and here is the accessing template function - template const map& get() const; -}; - -// Explicit specializations of a member function shall be declared in -// the namespace of which the class template is a member. -template<> const EFMap& EndgameFunctions::get() const { return maps.first; } -template<> const SFMap& EndgameFunctions::get() const { return maps.second; } - -//// -//// Functions -//// +} // namespace -/// MaterialInfoTable c'tor and d'tor, called once by each thread -MaterialInfoTable::MaterialInfoTable() { - - entries = new MaterialInfo[MaterialTableSize]; - funcs = new EndgameFunctions(); - - if (!entries || !funcs) - { - cerr << "Failed to allocate " << MaterialTableSize * sizeof(MaterialInfo) - << " bytes for material hash table." << endl; - exit(EXIT_FAILURE); - } - memset(entries, 0, MaterialTableSize * sizeof(MaterialInfo)); -} - -MaterialInfoTable::~MaterialInfoTable() { - - delete funcs; - delete [] entries; -} - - -/// MaterialInfoTable::game_phase() calculates the phase given the current -/// position. Because the phase is strictly a function of the material, it -/// is stored in MaterialInfo. - -Phase MaterialInfoTable::game_phase(const Position& pos) { - - Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK); +/// MaterialInfoTable c'tor and d'tor allocate and free the space for Endgames - if (npm >= MidgameLimit) - return PHASE_MIDGAME; +void MaterialInfoTable::init() { Base::init(); if (!funcs) funcs = new Endgames(); } +MaterialInfoTable::~MaterialInfoTable() { delete funcs; } - if (npm <= EndgameLimit) - return PHASE_ENDGAME; - return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit)); -} - -/// MaterialInfoTable::get_material_info() takes a position object as input, +/// MaterialInfoTable::material_info() takes a position object as input, /// computes or looks up a MaterialInfo object, and returns a pointer to it. /// If the material configuration is not already present in the table, it /// is stored there, so we don't have to recompute everything when the /// same material configuration occurs again. -MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { +MaterialInfo* MaterialInfoTable::material_info(const Position& pos) const { - Key key = pos.get_material_key(); - unsigned index = unsigned(key & (MaterialTableSize - 1)); - MaterialInfo* mi = entries + index; + Key key = pos.material_key(); + MaterialInfo* mi = probe(key); // If mi->key matches the position's material hash key, it means that we // have analysed this material configuration before, and we can simply @@ -190,10 +107,10 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { if (mi->key == key) return mi; - // Clear the MaterialInfo object, and set its key + // Initialize MaterialInfo entry memset(mi, 0, sizeof(MaterialInfo)); - mi->factor[WHITE] = mi->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL; mi->key = key; + mi->factor[WHITE] = mi->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL; // Store game phase mi->gamePhase = MaterialInfoTable::game_phase(pos); @@ -201,18 +118,22 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { // Let's look if we have a specialized evaluation function for this // particular material configuration. First we look for a fixed // configuration one, then a generic one if previous search failed. - if ((mi->evaluationFunction = funcs->get(key)) != NULL) + if ((mi->evaluationFunction = funcs->get(key)) != NULL) return mi; - if (is_KXK(pos) || is_KXK(pos)) + if (is_KXK(pos)) { - mi->evaluationFunction = is_KXK(pos) ? &EvaluateKXK[WHITE] : &EvaluateKXK[BLACK]; + mi->evaluationFunction = &EvaluateKXK[WHITE]; return mi; } - if ( pos.pieces(PAWN) == EmptyBoardBB - && pos.pieces(ROOK) == EmptyBoardBB - && pos.pieces(QUEEN) == EmptyBoardBB) + if (is_KXK(pos)) + { + mi->evaluationFunction = &EvaluateKXK[BLACK]; + return mi; + } + + if (!pos.pieces(PAWN) && !pos.pieces(ROOK) && !pos.pieces(QUEEN)) { // Minor piece endgame with at least one minor piece per side and // no pawns. Note that the case KmmK is already handled by KXK. @@ -222,7 +143,7 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { if ( pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2 && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2) { - mi->evaluationFunction = &EvaluateKmmKm[WHITE]; + mi->evaluationFunction = &EvaluateKmmKm[pos.side_to_move()]; return mi; } } @@ -232,9 +153,9 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { // // We face problems when there are several conflicting applicable // scaling functions and we need to decide which one to use. - SF* sf; + EndgameBase* sf; - if ((sf = funcs->get(key)) != NULL) + if ((sf = funcs->get(key)) != NULL) { mi->scalingFunction[sf->color()] = sf; return mi; @@ -243,10 +164,10 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { // Generic scaling functions that refer to more then one material // distribution. Should be probed after the specialized ones. // Note that these ones don't return after setting the function. - if (is_KBPsK(pos)) + if (is_KBPsKs(pos)) mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE]; - if (is_KBPsK(pos)) + if (is_KBPsKs(pos)) mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK]; if (is_KQKRPs(pos)) @@ -255,7 +176,10 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { else if (is_KQKRPs(pos)) mi->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK]; - if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == VALUE_ZERO) + Value npm_w = pos.non_pawn_material(WHITE); + Value npm_b = pos.non_pawn_material(BLACK); + + if (npm_w + npm_b == VALUE_ZERO) { if (pos.piece_count(BLACK, PAWN) == 0) { @@ -276,160 +200,87 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { } } + // No pawns makes it difficult to win, even with a material advantage + if (pos.piece_count(WHITE, PAWN) == 0 && npm_w - npm_b <= BishopValueMidgame) + { + mi->factor[WHITE] = uint8_t + (npm_w == npm_b || npm_w < RookValueMidgame ? 0 : NoPawnsSF[std::min(pos.piece_count(WHITE, BISHOP), 2)]); + } + + if (pos.piece_count(BLACK, PAWN) == 0 && npm_b - npm_w <= BishopValueMidgame) + { + mi->factor[BLACK] = uint8_t + (npm_w == npm_b || npm_b < RookValueMidgame ? 0 : NoPawnsSF[std::min(pos.piece_count(BLACK, BISHOP), 2)]); + } + // Compute the space weight - if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= - 2*QueenValueMidgame + 4*RookValueMidgame + 2*KnightValueMidgame) + if (npm_w + npm_b >= 2 * QueenValueMidgame + 4 * RookValueMidgame + 2 * KnightValueMidgame) { - int minorPieceCount = pos.piece_count(WHITE, KNIGHT) - + pos.piece_count(BLACK, KNIGHT) - + pos.piece_count(WHITE, BISHOP) - + pos.piece_count(BLACK, BISHOP); + int minorPieceCount = pos.piece_count(WHITE, KNIGHT) + pos.piece_count(WHITE, BISHOP) + + pos.piece_count(BLACK, KNIGHT) + pos.piece_count(BLACK, BISHOP); mi->spaceWeight = minorPieceCount * minorPieceCount; } - // Evaluate the material balance + // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder + // for the bishop pair "extended piece", this allow us to be more flexible + // in defining bishop pair bonuses. const int pieceCount[2][8] = { { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT), - pos.piece_count(WHITE, BISHOP), pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) }, + pos.piece_count(WHITE, BISHOP) , pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) }, { pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT), - pos.piece_count(BLACK, BISHOP), pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } }; + pos.piece_count(BLACK, BISHOP) , pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } }; - Color c, them; - int sign, pt1, pt2, pc; - int v, vv, matValue = 0; - - for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign) - { - // No pawns makes it difficult to win, even with a material advantage - if ( pos.piece_count(c, PAWN) == 0 - && pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c)) <= BishopValueMidgame) - { - if ( pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c)) - || pos.non_pawn_material(c) < RookValueMidgame) - mi->factor[c] = 0; - else - { - switch (pos.piece_count(c, BISHOP)) { - case 2: - mi->factor[c] = 32; - break; - case 1: - mi->factor[c] = 12; - break; - case 0: - mi->factor[c] = 6; - break; - } - } - } - - // Redundancy of major pieces, formula based on Kaufman's paper - // "The Evaluation of Material Imbalances in Chess" - // http://mywebpages.comcast.net/danheisman/Articles/evaluation_of_material_imbalance.htm - if (pieceCount[c][ROOK] >= 1) - matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty); - - them = opposite_color(c); - v = 0; - - // Second-degree polynomial material imbalance by Tord Romstad - // - // We use PIECE_TYPE_NONE as a place holder for the bishop pair "extended piece", - // this allow us to be more flexible in defining bishop pair bonuses. - for (pt1 = PIECE_TYPE_NONE; pt1 <= QUEEN; pt1++) - { - pc = pieceCount[c][pt1]; - if (!pc) - continue; - - vv = LinearCoefficients[pt1]; - - for (pt2 = PIECE_TYPE_NONE; pt2 <= pt1; pt2++) - vv += pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2] - + pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2]; - - v += pc * vv; - } - matValue += sign * v; - } - mi->value = (int16_t)(matValue / 16); + mi->value = int16_t((imbalance(pieceCount) - imbalance(pieceCount)) / 16); return mi; } -/// EndgameFunctions member definitions - -EndgameFunctions::EndgameFunctions() { +/// MaterialInfoTable::imbalance() calculates imbalance comparing piece count of each +/// piece type for both colors. - add >("KNNK"); - add >("KPK"); - add >("KBNK"); - add >("KRKP"); - add >("KRKB"); - add >("KRKN"); - add >("KQKR"); - add >("KBBKN"); +template +int MaterialInfoTable::imbalance(const int pieceCount[][8]) { - add >("KNPK"); - add >("KRPKR"); - add >("KBPKB"); - add >("KBPPKB"); - add >("KBPKN"); - add >("KRPPKRP"); -} + const Color Them = (Us == WHITE ? BLACK : WHITE); -EndgameFunctions::~EndgameFunctions() { + int pt1, pt2, pc, v; + int value = 0; - for (EFMap::const_iterator it = maps.first.begin(); it != maps.first.end(); ++it) - delete it->second; - - for (SFMap::const_iterator it = maps.second.begin(); it != maps.second.end(); ++it) - delete it->second; -} + // Redundancy of major pieces, formula based on Kaufman's paper + // "The Evaluation of Material Imbalances in Chess" + if (pieceCount[Us][ROOK] > 0) + value -= RedundantRookPenalty * (pieceCount[Us][ROOK] - 1) + + RedundantQueenPenalty * pieceCount[Us][QUEEN]; -Key EndgameFunctions::buildKey(const string& keyCode) { - - assert(keyCode.length() > 0 && keyCode.length() < 8); - assert(keyCode[0] == 'K'); - - string fen; - bool upcase = false; + // Second-degree polynomial material imbalance by Tord Romstad + for (pt1 = PIECE_TYPE_NONE; pt1 <= QUEEN; pt1++) + { + pc = pieceCount[Us][pt1]; + if (!pc) + continue; - // Build up a fen string with the given pieces, note that - // the fen string could be of an illegal position. - for (size_t i = 0; i < keyCode.length(); i++) - { - if (keyCode[i] == 'K') - upcase = !upcase; + v = LinearCoefficients[pt1]; - fen += char(upcase ? toupper(keyCode[i]) : tolower(keyCode[i])); - } - fen += char(8 - keyCode.length() + '0'); - fen += "/8/8/8/8/8/8/8 w - -"; - return Position(fen, false, 0).get_material_key(); -} + for (pt2 = PIECE_TYPE_NONE; pt2 <= pt1; pt2++) + v += QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2] + + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2]; -const string EndgameFunctions::swapColors(const string& keyCode) { - - // Build corresponding key for the opposite color: "KBPKN" -> "KNKBP" - size_t idx = keyCode.find('K', 1); - return keyCode.substr(idx) + keyCode.substr(0, idx); + value += pc * v; + } + return value; } -template -void EndgameFunctions::add(const string& keyCode) { - typedef typename T::Base F; - typedef map M; +/// MaterialInfoTable::game_phase() calculates the phase given the current +/// position. Because the phase is strictly a function of the material, it +/// is stored in MaterialInfo. - const_cast(get()).insert(pair(buildKey(keyCode), new T(WHITE))); - const_cast(get()).insert(pair(buildKey(swapColors(keyCode)), new T(BLACK))); -} +Phase MaterialInfoTable::game_phase(const Position& pos) { -template -T* EndgameFunctions::get(Key key) const { + Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK); - typename map::const_iterator it = get().find(key); - return it != get().end() ? it->second : NULL; + return npm >= MidgameLimit ? PHASE_MIDGAME + : npm <= EndgameLimit ? PHASE_ENDGAME + : Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit)); }