X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbook.cpp;h=b906d766779ae8fbd391ef2d99b066dd44428ee4;hp=b7237054723a7ab86469309625e21c861e63f2dc;hb=8ceef922662c75c33d105d99732475c125b01081;hpb=9ce74698463d0b3320892b060f0fbac70415f033 diff --git a/src/book.cpp b/src/book.cpp index b7237054..b906d766 100644 --- a/src/book.cpp +++ b/src/book.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2013 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 @@ -38,7 +38,7 @@ namespace { // A Polyglot book is a series of "entries" of 16 bytes. All integers are // stored in big-endian format, with highest byte first (regardless of size). // The entries are ordered according to the key in ascending order. - struct BookEntry { + struct Entry { uint64_t key; uint16_t move; uint16_t count; @@ -46,7 +46,15 @@ namespace { }; // Random numbers from PolyGlot, used to compute book hash keys - const Key PolyGlotRandoms[781] = { + const union { + Key PolyGlotRandoms[781]; + struct { + Key psq[12][64]; // [piece][square] + Key castle[4]; // [castle right] + Key enpassant[8]; // [file] + Key turn; + } Zobrist; + } PG = {{ 0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL, 0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL, 0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL, 0x0D7E765D58755C10ULL, @@ -308,51 +316,40 @@ namespace { 0x003A93D8B2806962ULL, 0x1C99DED33CB890A1ULL, 0xCF3145DE0ADD4289ULL, 0xD0E4427A5514FB72ULL, 0x77C621CC9FB3A483ULL, 0x67A34DAC4356550BULL, 0xF8D626AAAF278509ULL - }; - - // Offsets to the PolyGlotRandoms[] array of zobrist keys - const Key* ZobPiece = PolyGlotRandoms; - const Key* ZobCastle = ZobPiece + 12 * 64; // Pieces * squares - const Key* ZobEnPassant = ZobCastle + 4; // Castle flags - const Key* ZobTurn = ZobEnPassant + 8; // Number of files + }}; - // book_key() returns the PolyGlot hash key of the given position - uint64_t book_key(const Position& pos) { + // polyglot_key() returns the PolyGlot hash key of the given position + Key polyglot_key(const Position& pos) { - uint64_t key = 0; + Key key = 0; Bitboard b = pos.pieces(); while (b) { - // In PolyGlotRandoms[] pieces are stored in the following sequence: - // BP = 0, WP = 1, BN = 2, WN = 3, ... BK = 10, WK = 11 Square s = pop_lsb(&b); Piece p = pos.piece_on(s); - int pieceOfs = 2 * (type_of(p) - 1) + (color_of(p) == WHITE); - key ^= ZobPiece[64 * pieceOfs + s]; + + // PolyGlot pieces are: BP = 0, WP = 1, BN = 2, ... BK = 10, WK = 11 + key ^= PG.Zobrist.psq[2 * (type_of(p) - 1) + (color_of(p) == WHITE)][s]; } b = pos.can_castle(ALL_CASTLES); while (b) - key ^= ZobCastle[pop_lsb(&b)]; + key ^= PG.Zobrist.castle[pop_lsb(&b)]; if (pos.ep_square() != SQ_NONE) - key ^= ZobEnPassant[file_of(pos.ep_square())]; + key ^= PG.Zobrist.enpassant[file_of(pos.ep_square())]; if (pos.side_to_move() == WHITE) - key ^= ZobTurn[0]; + key ^= PG.Zobrist.turn; return key; } } // namespace -PolyglotBook::PolyglotBook() { - - for (int i = Time::now() % 10000; i > 0; i--) - RKiss.rand(); // Make random number generation less deterministic -} +PolyglotBook::PolyglotBook() : rkiss(Time::now() % 10000) {} PolyglotBook::~PolyglotBook() { if (is_open()) close(); } @@ -370,7 +367,7 @@ template PolyglotBook& PolyglotBook::operator>>(T& n) { return *this; } -template<> PolyglotBook& PolyglotBook::operator>>(BookEntry& e) { +template<> PolyglotBook& PolyglotBook::operator>>(Entry& e) { return *this >> e.key >> e.move >> e.count >> e.learn; } @@ -400,13 +397,13 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest if (fileName != fName && !open(fName.c_str())) return MOVE_NONE; - BookEntry e; + Entry e; uint16_t best = 0; unsigned sum = 0; Move move = MOVE_NONE; - uint64_t key = book_key(pos); + Key key = polyglot_key(pos); - seekg(find_first(key) * sizeof(BookEntry), ios_base::beg); + seekg(find_first(key) * sizeof(Entry), ios_base::beg); while (*this >> e, e.key == key && good()) { @@ -416,7 +413,7 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest // Choose book move according to its score. If a move has a very // high score it has higher probability to be choosen than a move // with lower score. Note that first entry is always chosen. - if ( (sum && RKiss.rand() % sum < e.count) + if ( (sum && rkiss.rand() % sum < e.count) || (pickBest && e.count == best)) move = Move(e.move); } @@ -439,9 +436,9 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest move = make(from_sq(move), to_sq(move), PieceType(pt + 1)); // Add 'special move' flags and verify it is legal - for (MoveList ml(pos); !ml.end(); ++ml) - if (move == (ml.move() & 0x3FFF)) - return ml.move(); + for (MoveList it(pos); !it.end(); ++it) + if (move == (*it ^ type_of(*it))) + return *it; return MOVE_NONE; } @@ -451,12 +448,12 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest /// the book file for the given key. Returns the index of the leftmost book /// entry with the same key as the input. -size_t PolyglotBook::find_first(uint64_t key) { +size_t PolyglotBook::find_first(Key key) { seekg(0, ios::end); // Move pointer to end, so tellg() gets file's size - size_t low = 0, mid, high = (size_t)tellg() / sizeof(BookEntry) - 1; - BookEntry e; + size_t low = 0, mid, high = (size_t)tellg() / sizeof(Entry) - 1; + Entry e; assert(low <= high); @@ -466,7 +463,7 @@ size_t PolyglotBook::find_first(uint64_t key) { assert(mid >= low && mid < high); - seekg(mid * sizeof(BookEntry), ios_base::beg); + seekg(mid * sizeof(Entry), ios_base::beg); *this >> e; if (key <= e.key)