X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=9873a44eb94c4dcf6205bbce3984a3eb3c5264de;hp=21b8ae3304a01bad8c52ce5e97399f1feb60a21d;hb=950c8436edc50857b83eb3e0cbaca06407764655;hpb=f7926ea41e65d2f687623904550771b7ee8f52a3 diff --git a/src/material.cpp b/src/material.cpp index 21b8ae33..9873a44e 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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 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 @@ -17,33 +17,34 @@ along with this program. If not, see . */ -#include // For std::min +#include // For std::min #include -#include +#include // For std::memset #include "material.h" +#include "thread.h" using namespace std; namespace { - // Polynomial material balance parameters + // Polynomial material imbalance parameters // pair pawn knight bishop rook queen const int Linear[6] = { 1852, -162, -1122, -183, 249, -154 }; - const int QuadraticSameSide[][PIECE_TYPE_NB] = { + const int QuadraticOurs[][PIECE_TYPE_NB] = { // OUR PIECES // pair pawn knight bishop rook queen { 0 }, // Bishop pair { 39, 2 }, // Pawn - { 35, 271, -4 }, // knight OUR PIECES + { 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] = { + const int QuadraticTheirs[][PIECE_TYPE_NB] = { // THEIR PIECES // pair pawn knight bishop rook queen { 0 }, // Bishop pair @@ -56,38 +57,35 @@ namespace { // 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 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) { - const Color Them = (Us == WHITE ? BLACK : WHITE); - return !more_than_one(pos.pieces(Them)) - && pos.non_pawn_material(Us) >= RookValueMg; + // Helper used to detect a given material distribution + bool is_KXK(const Position& pos, Color us) { + return !more_than_one(pos.pieces(~us)) + && pos.non_pawn_material(us) >= RookValueMg; } - template bool is_KBPsKs(const Position& pos) { - return pos.non_pawn_material(Us) == BishopValueMg - && pos.count(Us) == 1 - && pos.count(Us) >= 1; + bool is_KBPsKs(const Position& pos, Color us) { + 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.count(Us) - && pos.non_pawn_material(Us) == QueenValueMg - && pos.count(Us) == 1 - && pos.count(Them) == 1 - && pos.count(Them) >= 1; + bool is_KQKRPs(const Position& pos, Color us) { + return !pos.count(us) + && pos.non_pawn_material(us) == QueenValueMg + && pos.count(us) == 1 + && pos.count(~us) == 1 + && pos.count(~us) >= 1; } /// 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]) { @@ -104,8 +102,8 @@ namespace { 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]; + v += QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2] + + QuadraticTheirs[pt1][pt2] * pieceCount[Them][pt2]; bonus += pieceCount[Us][pt1] * v; } @@ -117,86 +115,74 @@ 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. +/// Material::probe() looks up the current position's material configuration in +/// the material hash table. It returns a pointer to the Entry if the position +/// is found. Otherwise a new Entry is computed and stored there, so we don't +/// have to recompute all when the same material configuration occurs again. -Entry* probe(const Position& pos, Table& entries, Endgames& endgames) { +Entry* probe(const Position& pos) { Key key = pos.material_key(); - Entry* e = entries[key]; + Entry* e = pos.this_thread()->materialTable[key]; - // 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 (e->key == key) return e; std::memset(e, 0, sizeof(Entry)); e->key = key; e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL; - e->gamePhase = game_phase(pos); + e->gamePhase = pos.game_phase(); // 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)) + if (pos.this_thread()->endgames.probe(key, e->evaluationFunction)) return e; - if (is_KXK(pos)) - { - e->evaluationFunction = &EvaluateKXK[WHITE]; - return e; - } - - if (is_KXK(pos)) - { - e->evaluationFunction = &EvaluateKXK[BLACK]; - return e; - } + for (Color c = WHITE; c <= BLACK; ++c) + if (is_KXK(pos, c)) + { + e->evaluationFunction = &EvaluateKXK[c]; + return e; + } - // OK, we didn't find any special evaluation function for the current - // material configuration. Is there a suitable scaling function? - // - // We face problems when there are several conflicting applicable - // scaling functions and we need to decide which one to use. + // OK, we didn't find any special evaluation function for the current material + // configuration. Is there a suitable specialized scaling function? EndgameBase* sf; - if (endgames.probe(key, sf)) + if (pos.this_thread()->endgames.probe(key, sf)) { - e->scalingFunction[sf->color()] = sf; + e->scalingFunction[sf->strong_side()] = sf; // Only strong color assigned return e; } - // 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)) - e->scalingFunction[WHITE] = &ScaleKBPsK[WHITE]; - - if (is_KBPsKs(pos)) - e->scalingFunction[BLACK] = &ScaleKBPsK[BLACK]; - - if (is_KQKRPs(pos)) - e->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE]; + // We didn't find any specialized scaling function, so fall back on generic + // ones that refer to more than one material distribution. Note that in this + // case we don't return after setting the function. + for (Color c = WHITE; c <= BLACK; ++c) + { + if (is_KBPsKs(pos, c)) + e->scalingFunction[c] = &ScaleKBPsK[c]; - else if (is_KQKRPs(pos)) - e->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK]; + else if (is_KQKRPs(pos, c)) + e->scalingFunction[c] = &ScaleKQKRPs[c]; + } Value npm_w = pos.non_pawn_material(WHITE); Value npm_b = pos.non_pawn_material(BLACK); - if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) + if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board { if (!pos.count(BLACK)) { assert(pos.count(WHITE) >= 2); + e->scalingFunction[WHITE] = &ScaleKPsK[WHITE]; } else if (!pos.count(WHITE)) { assert(pos.count(BLACK) >= 2); + e->scalingFunction[BLACK] = &ScaleKPsK[BLACK]; } else if (pos.count(WHITE) == 1 && pos.count(BLACK) == 1) @@ -208,14 +194,16 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) { } } - // 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). + // Zero or just one pawn makes it difficult to win, even with a small material + // advantage. This catches some trivial draws like KK, KBK and KNK and gives a + // 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); + e->factor[WHITE] = uint8_t(npm_w < RookValueMg ? SCALE_FACTOR_DRAW : + npm_b <= BishopValueMg ? 4 : 12); 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); + 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; @@ -223,40 +211,17 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) { 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 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg) - { - int minorPieceCount = pos.count(WHITE) + pos.count(WHITE) - + pos.count(BLACK) + pos.count(BLACK); - - 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", which allows us to be more flexible // in defining bishop pair bonuses. - const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = { + 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); + e->value = int16_t((imbalance(PieceCount) - imbalance(PieceCount)) / 16); return e; } - -/// Material::game_phase() calculates the phase given the current -/// position. Because the phase is strictly a function of the material, it -/// is stored in MaterialEntry. - -Phase 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