X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=a14e3370cad9c4a69afd507c193d09b52801b2c1;hp=cf1019ac07cd3646c036499353556d50fce956e1;hb=b15dcd977487c58409de48016eb7680850481d5d;hpb=c2d42ea8339b49e52a116e488214a14fda09d413 diff --git a/src/material.cpp b/src/material.cpp index cf1019ac..a14e3370 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) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 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 @@ -17,9 +17,9 @@ along with this program. If not, see . */ +#include // For std::min #include #include -#include #include "material.h" @@ -27,30 +27,35 @@ using namespace std; 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); - - 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[][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 } }; - - // Endgame evaluation and scaling functions accessed direcly and not through - // the function maps because correspond to more then one material hash key. - Endgame EvaluateKmmKm[] = { Endgame(WHITE), Endgame(BLACK) }; + // pair pawn knight bishop rook queen + const int Linear[6] = { 1852, -162, -1122, -183, 249, -154 }; + + const int QuadraticSameSide[][PIECE_TYPE_NB] = { + // OUR PIECES + // pair pawn knight bishop rook queen + { 0 }, // Bishop pair + { 39, 2 }, // Pawn + { 35, 271, -4 }, // Knight OUR PIECES + { 0, 105, 4, 0 }, // Bishop + { -27, -2, 46, 100, -141 }, // Rook + {-177, 25, 129, 142, -137, 0 } // Queen + }; + + const int QuadraticOppositeSide[][PIECE_TYPE_NB] = { + // THEIR PIECES + // pair pawn knight bishop rook queen + { 0 }, // Bishop pair + { 37, 0 }, // Pawn + { 10, 62, 0 }, // Knight OUR PIECES + { 57, 64, 39, 0 }, // Bishop + { 50, 40, 23, -22, 0 }, // Rook + { 98, 105, -39, 141, 274, 0 } // Queen + }; + + // Endgame evaluation and scaling functions are accessed directly and not through + // the function maps because they correspond to more than one material hash key. Endgame EvaluateKXK[] = { Endgame(WHITE), Endgame(BLACK) }; Endgame ScaleKBPsK[] = { Endgame(WHITE), Endgame(BLACK) }; @@ -61,91 +66,94 @@ namespace { // 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; + return !more_than_one(pos.pieces(Them)) + && pos.non_pawn_material(Us) >= RookValueMg; } 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; + return pos.non_pawn_material(Us) == BishopValueMg + && pos.count(Us) == 1 + && pos.count(Us) >= 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; + return !pos.count(Us) + && pos.non_pawn_material(Us) == QueenValueMg + && pos.count(Us) == 1 + && pos.count(Them) == 1 + && pos.count(Them) >= 1; } -} // namespace + /// imbalance() calculates the imbalance by comparing the piece count of each + /// piece type for both colors. + template + int imbalance(const int pieceCount[][PIECE_TYPE_NB]) { -/// MaterialInfoTable c'tor and d'tor allocate and free the space for Endgames + const Color Them = (Us == WHITE ? BLACK : WHITE); + + int bonus = 0; + + // Second-degree polynomial material imbalance by Tord Romstad + for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1) + { + if (!pieceCount[Us][pt1]) + continue; -void MaterialInfoTable::init() { Base::init(); if (!funcs) funcs = new Endgames(); } -MaterialInfoTable::~MaterialInfoTable() { delete funcs; } + int v = Linear[pt1]; + for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2) + v += QuadraticSameSide[pt1][pt2] * pieceCount[Us][pt2] + + QuadraticOppositeSide[pt1][pt2] * pieceCount[Them][pt2]; -/// 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. + bonus += pieceCount[Us][pt1] * v; + } -MaterialInfo* MaterialInfoTable::material_info(const Position& pos) const { + return bonus; + } + +} // namespace + +namespace Material { + +/// Material::probe() takes a position object as input, looks up a MaterialEntry +/// object, and returns a pointer to it. If the material configuration is not +/// already present in the table, it is computed and stored there, so we don't +/// have to recompute everything when the same material configuration occurs again. + +Entry* probe(const Position& pos, Table& entries, Endgames& endgames) { Key key = pos.material_key(); - MaterialInfo* mi = probe(key); + Entry* e = entries[key]; - // If mi->key matches the position's material hash key, it means that we + // If e->key matches the position's material hash key, it means that we // have analysed this material configuration before, and we can simply // return the information we found the last time instead of recomputing it. - if (mi->key == key) - return mi; + if (e->key == key) + return e; - // Initialize MaterialInfo entry - memset(mi, 0, sizeof(MaterialInfo)); - mi->key = key; - mi->factor[WHITE] = mi->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL; + std::memset(e, 0, sizeof(Entry)); + e->key = key; + e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL; + e->gamePhase = pos.game_phase(); - // 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 - // configuration one, then a generic one if previous search failed. - if ((mi->evaluationFunction = funcs->get(key)) != NULL) - return mi; + // Let's look if we have a specialized evaluation function for this particular + // material configuration. Firstly we look for a fixed configuration one, then + // for a generic one if the previous search failed. + if (endgames.probe(key, e->evaluationFunction)) + return e; if (is_KXK(pos)) { - mi->evaluationFunction = &EvaluateKXK[WHITE]; - return mi; + e->evaluationFunction = &EvaluateKXK[WHITE]; + return e; } 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. - 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[pos.side_to_move()]; - return mi; - } + e->evaluationFunction = &EvaluateKXK[BLACK]; + return e; } // OK, we didn't find any special evaluation function for the current @@ -155,132 +163,86 @@ MaterialInfo* MaterialInfoTable::material_info(const Position& pos) const { // scaling functions and we need to decide which one to use. EndgameBase* sf; - if ((sf = funcs->get(key)) != NULL) + if (endgames.probe(key, sf)) { - mi->scalingFunction[sf->color()] = sf; - return mi; + e->scalingFunction[sf->color()] = sf; + return e; } - // Generic scaling functions that refer to more then one material - // distribution. Should be probed after the specialized ones. + // Generic scaling functions that refer to more than one material + // distribution. They should be probed after the specialized ones. // Note that these ones don't return after setting the function. if (is_KBPsKs(pos)) - mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE]; + e->scalingFunction[WHITE] = &ScaleKBPsK[WHITE]; if (is_KBPsKs(pos)) - mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK]; + e->scalingFunction[BLACK] = &ScaleKBPsK[BLACK]; if (is_KQKRPs(pos)) - mi->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE]; + e->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE]; else if (is_KQKRPs(pos)) - mi->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK]; + e->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 (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) { - if (pos.piece_count(BLACK, PAWN) == 0) + if (!pos.count(BLACK)) { - assert(pos.piece_count(WHITE, PAWN) >= 2); - mi->scalingFunction[WHITE] = &ScaleKPsK[WHITE]; + assert(pos.count(WHITE) >= 2); + e->scalingFunction[WHITE] = &ScaleKPsK[WHITE]; } - else if (pos.piece_count(WHITE, PAWN) == 0) + else if (!pos.count(WHITE)) { - assert(pos.piece_count(BLACK, PAWN) >= 2); - mi->scalingFunction[BLACK] = &ScaleKPsK[BLACK]; + assert(pos.count(BLACK) >= 2); + e->scalingFunction[BLACK] = &ScaleKPsK[BLACK]; } - else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1) + else if (pos.count(WHITE) == 1 && pos.count(BLACK) == 1) { // This is a special case because we set scaling functions // for both colors instead of only one. - mi->scalingFunction[WHITE] = &ScaleKPKP[WHITE]; - mi->scalingFunction[BLACK] = &ScaleKPKP[BLACK]; + e->scalingFunction[WHITE] = &ScaleKPKP[WHITE]; + e->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] = uint8_t - (npm_w == npm_b || npm_w < RookValueMidgame ? 0 : NoPawnsSF[std::min(pos.piece_count(WHITE, BISHOP), 2)]); - } + // No pawns makes it difficult to win, even with a material advantage. This + // catches some trivial draws like KK, KBK and KNK and gives a very drawish + // scale factor for cases such as KRKBP and KmmKm (except for KBBKN). + if (!pos.count(WHITE) && npm_w - npm_b <= BishopValueMg) + e->factor[WHITE] = uint8_t(npm_w < RookValueMg ? SCALE_FACTOR_DRAW : npm_b <= BishopValueMg ? 4 : 12); - 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)]); - } + if (!pos.count(BLACK) && npm_b - npm_w <= BishopValueMg) + e->factor[BLACK] = uint8_t(npm_b < RookValueMg ? SCALE_FACTOR_DRAW : npm_w <= BishopValueMg ? 4 : 12); + + if (pos.count(WHITE) == 1 && npm_w - npm_b <= BishopValueMg) + e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN; + + if (pos.count(BLACK) == 1 && npm_b - npm_w <= BishopValueMg) + e->factor[BLACK] = (uint8_t) SCALE_FACTOR_ONEPAWN; // Compute the space weight - if (npm_w + npm_b >= 2 * QueenValueMidgame + 4 * RookValueMidgame + 2 * KnightValueMidgame) + if (npm_w + npm_b >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg) { - int minorPieceCount = pos.piece_count(WHITE, KNIGHT) + pos.piece_count(WHITE, BISHOP) - + pos.piece_count(BLACK, KNIGHT) + pos.piece_count(BLACK, BISHOP); + int minorPieceCount = pos.count(WHITE) + pos.count(WHITE) + + pos.count(BLACK) + pos.count(BLACK); - mi->spaceWeight = minorPieceCount * minorPieceCount; + e->spaceWeight = make_score(minorPieceCount * minorPieceCount, 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 + // for the bishop pair "extended piece", which allows 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) } }; - - mi->value = int16_t((imbalance(pieceCount) - imbalance(pieceCount)) / 16); - return mi; + const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = { + { pos.count(WHITE) > 1, pos.count(WHITE), pos.count(WHITE), + pos.count(WHITE) , pos.count(WHITE), pos.count(WHITE) }, + { pos.count(BLACK) > 1, pos.count(BLACK), pos.count(BLACK), + pos.count(BLACK) , pos.count(BLACK), pos.count(BLACK) } }; + + e->value = (int16_t)((imbalance(pieceCount) - imbalance(pieceCount)) / 16); + return e; } - -/// MaterialInfoTable::imbalance() calculates imbalance comparing piece count of each -/// piece type for both colors. - -template -int MaterialInfoTable::imbalance(const int pieceCount[][8]) { - - const Color Them = (Us == WHITE ? BLACK : WHITE); - - int pt1, pt2, pc, v; - 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; - - v = LinearCoefficients[pt1]; - - for (pt2 = PIECE_TYPE_NONE; pt2 <= pt1; pt2++) - v += QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2] - + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2]; - - value += pc * v; - } - 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); - - return npm >= MidgameLimit ? PHASE_MIDGAME - : npm <= EndgameLimit ? PHASE_ENDGAME - : Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit)); -} +} // namespace Material