X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=31550720c05a48de8c0f764dd56860a9d4afc501;hp=b16710588bbed14f4c1a5c7e61cc027b9188cf4c;hb=08c464c690e62b874b7d9b34dfabf455820153d6;hpb=46ffea46ea64ff070cff07ce374f3618e9b631c8 diff --git a/src/material.cpp b/src/material.cpp index b1671058..31550720 100644 --- a/src/material.cpp +++ b/src/material.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) 2008-2009 Marco Costalba + Copyright (C) 2008-2010 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 @@ -17,56 +17,75 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include -#include +#include #include #include "material.h" using namespace std; +namespace { -//// -//// Local definitions -//// + // Values modified by Joona Kiiski + const Value MidgameLimit = Value(15581); + const Value EndgameLimit = Value(3998); -namespace { + // Scale factors used when one side has no more pawns + const uint8_t NoPawnsSF[4] = { 6, 12, 32 }; // Polynomial material balance parameters const Value RedundantQueenPenalty = Value(320); const Value RedundantRookPenalty = Value(554); - const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 }; - const int QuadraticCoefficientsSameColor[][6] = { + const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 }; + + const int QuadraticCoefficientsSameColor[][8] = { { 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 }, { 7, 25, 4, 7, 7, 7 }, { -27, -2, 46, 100, 56, 7 }, { 58, 29, 83, 148, -3, -25 } }; - const int QuadraticCoefficientsOppositeColor[][6] = { + const int QuadraticCoefficientsOppositeColor[][8] = { { 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 } }; - // 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 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; -} + 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) }; + + // Helper templates used to detect a given material distribution + template bool is_KXK(const Position& pos) { + const Color Them = (Us == WHITE ? BLACK : WHITE); + return pos.non_pawn_material(Them) == VALUE_ZERO + && pos.piece_count(Them, PAWN) == 0 + && pos.non_pawn_material(Us) >= RookValueMidgame; + } + 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; + } + + template bool is_KQKRPs(const Position& pos) { + const Color Them = (Us == WHITE ? BLACK : WHITE); + return pos.piece_count(Us, PAWN) == 0 + && pos.non_pawn_material(Us) == QueenValueMidgame + && pos.piece_count(Us, QUEEN) == 1 + && 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 @@ -85,48 +104,23 @@ private: static Key buildKey(const string& keyCode); static const string swapColors(const string& keyCode); - // Here we store two maps, for evaluate and scaling functions - pair, map > maps; + // Here we store two maps, for evaluate and scaling functions... + pair maps; - // Maps accessing functions returning const and non-const references - template const map& get() const { return maps.first; } - template map& get() { return maps.first; } + // ...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 map& -EndgameFunctions::get() const { return maps.second; } - -template<> map& -EndgameFunctions::get() { return maps.second; } - - -//// -//// Functions -//// +template<> const EFMap& EndgameFunctions::get() const { return maps.first; } +template<> const SFMap& EndgameFunctions::get() const { return maps.second; } -/// MaterialInfoTable c'tor and d'tor, called once by each thread -MaterialInfoTable::MaterialInfoTable(unsigned int numOfEntries) { +/// MaterialInfoTable c'tor and d'tor allocate and free the space for EndgameFunctions - size = numOfEntries; - entries = new MaterialInfo[size]; - funcs = new EndgameFunctions(); - - if (!entries || !funcs) - { - cerr << "Failed to allocate " << numOfEntries * sizeof(MaterialInfo) - << " bytes for material hash table." << endl; - Application::exit_with_failure(); - } -} - -MaterialInfoTable::~MaterialInfoTable() { - - delete funcs; - delete [] entries; -} +MaterialInfoTable::MaterialInfoTable() { funcs = new EndgameFunctions(); } +MaterialInfoTable::~MaterialInfoTable() { delete funcs; } /// MaterialInfoTable::get_material_info() takes a position object as input, @@ -135,11 +129,10 @@ MaterialInfoTable::~MaterialInfoTable() { /// 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::get_material_info(const Position& pos) const { Key key = pos.get_material_key(); - int index = key & (size - 1); - MaterialInfo* mi = entries + index; + MaterialInfo* mi = find(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 @@ -147,9 +140,13 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { if (mi->key == key) return mi; - // Clear the MaterialInfo object, and set its key - mi->clear(); + // Initialize MaterialInfo entry + memset(mi, 0, sizeof(MaterialInfo)); mi->key = key; + mi->factor[WHITE] = mi->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL; + + // Store game phase + mi->gamePhase = MaterialInfoTable::game_phase(pos); // Let's look if we have a specialized evaluation function for this // particular material configuration. First we look for a fixed @@ -157,33 +154,29 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { if ((mi->evaluationFunction = funcs->get(key)) != NULL) return mi; - else if ( pos.non_pawn_material(BLACK) == Value(0) - && pos.piece_count(BLACK, PAWN) == 0 - && pos.non_pawn_material(WHITE) >= RookValueMidgame) + if (is_KXK(pos)) { - mi->evaluationFunction = &EvaluateKXK; + mi->evaluationFunction = &EvaluateKXK[WHITE]; return mi; } - else if ( pos.non_pawn_material(WHITE) == Value(0) - && pos.piece_count(WHITE, PAWN) == 0 - && pos.non_pawn_material(BLACK) >= RookValueMidgame) + + if (is_KXK(pos)) { - mi->evaluationFunction = &EvaluateKKX; + mi->evaluationFunction = &EvaluateKXK[BLACK]; return mi; } - else if ( pos.pawns() == EmptyBoardBB - && pos.rooks() == EmptyBoardBB - && pos.queens() == EmptyBoardBB) + + 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. - assert(pos.knights(WHITE) | pos.bishops(WHITE)); - assert(pos.knights(BLACK) | pos.bishops(BLACK)); + assert((pos.pieces(KNIGHT, WHITE) | pos.pieces(BISHOP, WHITE))); + assert((pos.pieces(KNIGHT, BLACK) | pos.pieces(BISHOP, BLACK))); 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; + mi->evaluationFunction = &EvaluateKmmKm[WHITE]; return mi; } } @@ -191,10 +184,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { // OK, we didn't find any special evaluation function for the current // material configuration. Is there a suitable scaling function? // - // The code below is rather messy, and it could easily get worse later, - // if we decide to add more special cases. We face problems when there - // are several conflicting applicable scaling functions and we need to - // decide which one to use. + // We face problems when there are several conflicting applicable + // scaling functions and we need to decide which one to use. SF* sf; if ((sf = funcs->get(key)) != NULL) @@ -206,130 +197,133 @@ 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 ( pos.non_pawn_material(WHITE) == BishopValueMidgame - && pos.piece_count(WHITE, BISHOP) == 1 - && pos.piece_count(WHITE, PAWN) >= 1) - 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] = &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] = &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] = &ScaleKRPsKQ; - - if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0)) + if (is_KBPsKs(pos)) + mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE]; + + if (is_KBPsKs(pos)) + mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK]; + + if (is_KQKRPs(pos)) + mi->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE]; + + else if (is_KQKRPs(pos)) + mi->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK]; + + 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) { assert(pos.piece_count(WHITE, PAWN) >= 2); - mi->scalingFunction[WHITE] = &ScaleKPsK; + mi->scalingFunction[WHITE] = &ScaleKPsK[WHITE]; } else if (pos.piece_count(WHITE, PAWN) == 0) { assert(pos.piece_count(BLACK, PAWN) >= 2); - mi->scalingFunction[BLACK] = &ScaleKKPs; + mi->scalingFunction[BLACK] = &ScaleKPsK[BLACK]; } 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; + mi->scalingFunction[WHITE] = &ScaleKPKP[WHITE]; + mi->scalingFunction[BLACK] = &ScaleKPKP[BLACK]; } } + // 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] = + (npm_w == npm_b || npm_w < RookValueMidgame ? 0 : NoPawnsSF[Min(pos.piece_count(WHITE, BISHOP), 2)]); + } + + if (pos.piece_count(BLACK, PAWN) == 0 && npm_b - npm_w <= BishopValueMidgame) + { + mi->factor[BLACK] = + (npm_w == npm_b || npm_b < RookValueMidgame ? 0 : NoPawnsSF[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 - 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; - int matValue = 0; + // 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(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) } }; - 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; - } - } - } + mi->value = (int16_t)(imbalance(pieceCount) - imbalance(pieceCount)) / 16; + return mi; +} - // 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); +/// MaterialInfoTable::imbalance() calculates imbalance comparing piece count of each +/// piece type for both colors. - // 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++) - { - int c1 = sign * pieceCount[c][pt1]; - if (!c1) - continue; +template +int MaterialInfoTable::imbalance(const int pieceCount[][8]) { - matValue += c1 * LinearCoefficients[pt1]; + const Color Them = (Us == WHITE ? BLACK : WHITE); - 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]; - } - } + int pt1, pt2, pc, vv; + int value = 0; + + // 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]; + + // Second-degree polynomial material imbalance by Tord Romstad + for (pt1 = PIECE_TYPE_NONE; pt1 <= QUEEN; pt1++) + { + pc = pieceCount[Us][pt1]; + if (!pc) + continue; + + vv = LinearCoefficients[pt1]; + + for (pt2 = PIECE_TYPE_NONE; pt2 <= pt1; pt2++) + vv += QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2] + + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2]; + + value += pc * vv; } - mi->value = int16_t(matValue / 16); - return mi; + return value; +} + + +/// 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); + + if (npm >= MidgameLimit) + return PHASE_MIDGAME; + + if (npm <= EndgameLimit) + return PHASE_ENDGAME; + + return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit)); } -/// EndgameFunctions member definitions. +/// EndgameFunctions member definitions EndgameFunctions::EndgameFunctions() { @@ -348,24 +342,23 @@ EndgameFunctions::EndgameFunctions() { add >("KBPPKB"); add >("KBPKN"); add >("KRPPKRP"); - add >("KRPPKRP"); } EndgameFunctions::~EndgameFunctions() { - for (map::iterator it = maps.first.begin(); it != maps.first.end(); ++it) - delete (*it).second; + for (EFMap::const_iterator it = maps.first.begin(); it != maps.first.end(); ++it) + delete it->second; - for (map::iterator it = maps.second.begin(); it != maps.second.end(); ++it) - delete (*it).second; + for (SFMap::const_iterator it = maps.second.begin(); it != maps.second.end(); ++it) + delete it->second; } Key EndgameFunctions::buildKey(const string& keyCode) { - assert(keyCode.length() > 0 && keyCode[0] == 'K'); - assert(keyCode.length() < 8); + assert(keyCode.length() > 0 && keyCode.length() < 8); + assert(keyCode[0] == 'K'); - stringstream s; + string fen; bool upcase = false; // Build up a fen string with the given pieces, note that @@ -375,16 +368,17 @@ Key EndgameFunctions::buildKey(const string& keyCode) { if (keyCode[i] == 'K') upcase = !upcase; - s << char(upcase? toupper(keyCode[i]) : tolower(keyCode[i])); + fen += char(upcase ? toupper(keyCode[i]) : tolower(keyCode[i])); } - s << 8 - keyCode.length() << "/8/8/8/8/8/8/8 w -"; - return Position(s.str()).get_material_key(); + fen += char(8 - keyCode.length() + '0'); + fen += "/8/8/8/8/8/8/8 w - -"; + return Position(fen, false, 0).get_material_key(); } const string EndgameFunctions::swapColors(const string& keyCode) { // Build corresponding key for the opposite color: "KBPKN" -> "KNKBP" - size_t idx = keyCode.find("K", 1); + size_t idx = keyCode.find('K', 1); return keyCode.substr(idx) + keyCode.substr(0, idx); } @@ -392,14 +386,15 @@ template void EndgameFunctions::add(const string& keyCode) { typedef typename T::Base F; + typedef map M; - get().insert(pair(buildKey(keyCode), new T(WHITE))); - get().insert(pair(buildKey(swapColors(keyCode)), new T(BLACK))); + const_cast(get()).insert(pair(buildKey(keyCode), new T(WHITE))); + const_cast(get()).insert(pair(buildKey(swapColors(keyCode)), new T(BLACK))); } template T* EndgameFunctions::get(Key key) const { - typename map::const_iterator it(get().find(key)); - return (it != get().end() ? it->second : NULL); + typename map::const_iterator it = get().find(key); + return it != get().end() ? it->second : NULL; }