X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=cc8e896a143b46c5cea28dcb893a69550451c64b;hp=3fc05db8fc78e09c928f2464590d032988099b59;hb=bfd4421f490e721958a77b8304d8ebcb574a583f;hpb=20e87389019187dd7586d3ffb12b632d5ec5d048 diff --git a/src/material.cpp b/src/material.cpp index 3fc05db8..cc8e896a 100644 --- a/src/material.cpp +++ b/src/material.cpp @@ -28,7 +28,8 @@ #include "material.h" -using std::string; +using namespace std; + //// //// Local definitions @@ -36,20 +37,30 @@ using std::string; namespace { - // Values modified by Joona Kiiski - const Value BishopPairMidgameBonus = Value(109); - const Value BishopPairEndgameBonus = Value(97); + // Polynomial material balance parameters + const Value RedundantQueenPenalty = Value(320); + const Value RedundantRookPenalty = Value(554); + const int LinearCoefficients[6] = { 1709, -137, -1185, -166, 141, 59 }; + + const int QuadraticCoefficientsSameColor[][6] = { + { 0, 0, 0, 0, 0, 0 }, { 33, -6, 0, 0, 0, 0 }, { 29, 269, -12, 0, 0, 0 }, + { 0, 19, -4, 0, 0, 0 }, { -35, -10, 40, 95, 50, 0 }, { 52, 23, 78, 144, -11, -33 } }; - Key KNNKMaterialKey, KKNNMaterialKey; + const int QuadraticCoefficientsOppositeColor[][6] = { + { 0, 0, 0, 0, 0, 0 }, { -5, 0, 0, 0, 0, 0 }, { -33, 23, 0, 0, 0, 0 }, + { 17, 25, -3, 0, 0, 0 }, { 10, -2, -19, -67, 0, 0 }, { 69, 64, -41, 116, 137, 0 } }; - // Unmapped endgame evaluation and scaling functions, these + // Named endgame evaluation and scaling functions, these // are accessed direcly and not through the function maps. EvaluationFunction EvaluateKmmKm(WHITE); EvaluationFunction EvaluateKXK(WHITE), EvaluateKKX(BLACK); - ScalingFunction ScaleKBPK(WHITE), ScaleKKBP(BLACK); - ScalingFunction ScaleKQKRP(WHITE), ScaleKRPKQ(BLACK); + ScalingFunction ScaleKBPsK(WHITE), ScaleKKBPs(BLACK); + ScalingFunction ScaleKQKRPs(WHITE), ScaleKRPsKQ(BLACK); ScalingFunction ScaleKPsK(WHITE), ScaleKKPs(BLACK); ScalingFunction ScaleKPKPw(WHITE), ScaleKPKPb(BLACK); + + typedef EndgameEvaluationFunctionBase EF; + typedef EndgameScalingFunctionBase SF; } @@ -57,11 +68,10 @@ namespace { //// Classes //// -typedef EndgameEvaluationFunctionBase EF; -typedef EndgameScalingFunctionBase SF; - -/// See header for a class description. It is declared here to avoid -/// to include in the header file. +/// 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: @@ -75,46 +85,43 @@ private: static Key buildKey(const string& keyCode); static const string swapColors(const string& keyCode); - std::map EEFmap; - std::map ESFmap; + // Here we store two maps, for evaluate and scaling functions + pair, map > maps; - // Maps accessing functions for const and non-const references - template const std::map& map() const { return EEFmap; } - template std::map& map() { return EEFmap; } + // Maps accessing functions returning const and non-const references + template const map& get() const { return maps.first; } + template map& get() { return maps.first; } }; // Explicit specializations of a member function shall be declared in // the namespace of which the class template is a member. -template<> const std::map& -EndgameFunctions::map() const { return ESFmap; } +template<> const map& +EndgameFunctions::get() const { return maps.second; } -template<> std::map& -EndgameFunctions::map() { return ESFmap; } +template<> map& +EndgameFunctions::get() { return maps.second; } //// //// Functions //// - -/// Constructor for the MaterialInfoTable class +/// MaterialInfoTable c'tor and d'tor, called once by each thread MaterialInfoTable::MaterialInfoTable(unsigned int numOfEntries) { size = numOfEntries; entries = new MaterialInfo[size]; funcs = new EndgameFunctions(); + if (!entries || !funcs) { - std::cerr << "Failed to allocate " << (numOfEntries * sizeof(MaterialInfo)) - << " bytes for material hash table." << std::endl; + cerr << "Failed to allocate " << numOfEntries * sizeof(MaterialInfo) + << " bytes for material hash table." << endl; Application::exit_with_failure(); } } - -/// Destructor for the MaterialInfoTable class - MaterialInfoTable::~MaterialInfoTable() { delete funcs; @@ -144,14 +151,6 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { mi->clear(); mi->key = key; - // A special case before looking for a specialized evaluation function - // KNN vs K is a draw. - if (key == KNNKMaterialKey || key == KKNNMaterialKey) - { - mi->factor[WHITE] = mi->factor[BLACK] = 0; - return mi; - } - // 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. @@ -176,8 +175,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { && pos.rooks() == EmptyBoardBB && pos.queens() == EmptyBoardBB) { - // Minor piece endgame with at least one minor piece per side, - // and no pawns. + // Minor piece endgame with at least one minor piece per side and + // no pawns. Note that the case KmmK is already handled by KXK. assert(pos.knights(WHITE) | pos.bishops(WHITE)); assert(pos.knights(BLACK) | pos.bishops(BLACK)); @@ -204,29 +203,32 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { return mi; } + // 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 ( pos.non_pawn_material(WHITE) == BishopValueMidgame && pos.piece_count(WHITE, BISHOP) == 1 && pos.piece_count(WHITE, PAWN) >= 1) - mi->scalingFunction[WHITE] = &ScaleKBPK; + mi->scalingFunction[WHITE] = &ScaleKBPsK; if ( pos.non_pawn_material(BLACK) == BishopValueMidgame && pos.piece_count(BLACK, BISHOP) == 1 && pos.piece_count(BLACK, PAWN) >= 1) - mi->scalingFunction[BLACK] = &ScaleKKBP; + mi->scalingFunction[BLACK] = &ScaleKKBPs; if ( pos.piece_count(WHITE, PAWN) == 0 && pos.non_pawn_material(WHITE) == QueenValueMidgame && pos.piece_count(WHITE, QUEEN) == 1 && pos.piece_count(BLACK, ROOK) == 1 && pos.piece_count(BLACK, PAWN) >= 1) - mi->scalingFunction[WHITE] = &ScaleKQKRP; + mi->scalingFunction[WHITE] = &ScaleKQKRPs; else if ( pos.piece_count(BLACK, PAWN) == 0 && pos.non_pawn_material(BLACK) == QueenValueMidgame && pos.piece_count(BLACK, QUEEN) == 1 && pos.piece_count(WHITE, ROOK) == 1 && pos.piece_count(WHITE, PAWN) >= 1) - mi->scalingFunction[BLACK] = &ScaleKRPKQ; + mi->scalingFunction[BLACK] = &ScaleKRPsKQ; if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0)) { @@ -242,6 +244,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { } else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1) { + // This is a special case because we set scaling functions + // for both colors instead of only one. mi->scalingFunction[WHITE] = &ScaleKPKPw; mi->scalingFunction[BLACK] = &ScaleKPKPb; } @@ -260,11 +264,13 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { } // Evaluate the material balance - - Color c; + const int pieceCount[2][6] = { { 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(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) } }; + Color c, them; int sign; - Value egValue = Value(0); - Value mgValue = Value(0); + int matValue = 0; for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign) { @@ -291,46 +297,43 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { } } - // Bishop pair - if (pos.piece_count(c, BISHOP) >= 2) - { - mgValue += sign * BishopPairMidgameBonus; - egValue += sign * BishopPairEndgameBonus; - } - - // Knights are stronger when there are many pawns on the board. The - // formula is taken from Larry Kaufman's paper "The Evaluation of Material - // Imbalances in Chess": + // 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 - mgValue += sign * Value(pos.piece_count(c, KNIGHT)*(pos.piece_count(c, PAWN)-5)*16); - egValue += sign * Value(pos.piece_count(c, KNIGHT)*(pos.piece_count(c, PAWN)-5)*16); + if (pieceCount[c][ROOK] >= 1) + matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty); + + them = opposite_color(c); - // Redundancy of major pieces, again based on Kaufman's paper: - if (pos.piece_count(c, ROOK) >= 1) + // Second-degree polynomial material imbalance by Tord Romstad + // + // We use NO_PIECE_TYPE as a place holder for the bishop pair "extended piece", + // this allow us to be more flexible in defining bishop pair bonuses. + for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++) { - Value v = Value((pos.piece_count(c, ROOK) - 1) * 32 + pos.piece_count(c, QUEEN) * 16); - mgValue -= sign * v; - egValue -= sign * v; + int c1 = sign * pieceCount[c][pt1]; + if (!c1) + continue; + + matValue += c1 * LinearCoefficients[pt1]; + + for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++) + { + matValue += c1 * pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2]; + matValue += c1 * pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2]; + } } } - mi->mgValue = int16_t(mgValue); - mi->egValue = int16_t(egValue); + mi->value = int16_t(matValue / 16); return mi; } -/// EndgameFunctions member definitions. This class is used to store the maps -/// of end game and scaling functions that MaterialInfoTable will query for -/// each key. The maps are constant and are populated only at construction, -/// but are per-thread instead of globals to avoid expensive locks needed -/// because std::map is not guaranteed to be thread-safe even if accessed -/// only for a lookup. +/// EndgameFunctions member definitions. EndgameFunctions::EndgameFunctions() { - KNNKMaterialKey = buildKey("KNNK"); - KKNNMaterialKey = buildKey("KKNN"); - + add >("KNNK"); add >("KPK"); add >("KBNK"); add >("KRKP"); @@ -350,10 +353,10 @@ EndgameFunctions::EndgameFunctions() { EndgameFunctions::~EndgameFunctions() { - for (std::map::iterator it = EEFmap.begin(); it != EEFmap.end(); ++it) + for (map::iterator it = maps.first.begin(); it != maps.first.end(); ++it) delete (*it).second; - for (std::map::iterator it = ESFmap.begin(); it != ESFmap.end(); ++it) + for (map::iterator it = maps.second.begin(); it != maps.second.end(); ++it) delete (*it).second; } @@ -362,11 +365,11 @@ Key EndgameFunctions::buildKey(const string& keyCode) { assert(keyCode.length() > 0 && keyCode[0] == 'K'); assert(keyCode.length() < 8); - std::stringstream s; + stringstream s; bool upcase = false; - // Build up a fen substring with the given pieces, note - // that the fen string could be of an illegal position. + // 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') @@ -390,13 +393,13 @@ void EndgameFunctions::add(const string& keyCode) { typedef typename T::Base F; - map().insert(std::pair(buildKey(keyCode), new T(WHITE))); - map().insert(std::pair(buildKey(swapColors(keyCode)), new T(BLACK))); + get().insert(pair(buildKey(keyCode), new T(WHITE))); + get().insert(pair(buildKey(swapColors(keyCode)), new T(BLACK))); } template T* EndgameFunctions::get(Key key) const { - typename std::map::const_iterator it(map().find(key)); - return (it != map().end() ? it->second : NULL); + typename map::const_iterator it(get().find(key)); + return (it != get().end() ? it->second : NULL); }