X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbook.cpp;h=85a88fcb801e3499376d3038a8087bebbc2bdc4f;hp=1e4c9cc088aa277f998e70889cc285e8da3e20ab;hb=d9b96f0e492583bfb461e7e3c9510ddeae1e3fce;hpb=cb08413dc4e51ac246887613184b51b46bf11226 diff --git a/src/book.cpp b/src/book.cpp index 1e4c9cc0..85a88fcb 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) 2008-2009 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 @@ -30,32 +30,23 @@ //// #include +#include #include "book.h" -#include "mersenne.h" #include "movegen.h" using namespace std; -//// -//// Global variables -//// - -Book OpeningBook; - - //// //// Local definitions //// namespace { - /// Book entry size in bytes + // Book entry size in bytes const int EntrySize = 16; - - /// Random numbers from PolyGlot, used to compute book hash keys - + // Random numbers from PolyGlot, used to compute book hash keys const uint64_t Random64[781] = { 0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL, 0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL, @@ -320,17 +311,13 @@ namespace { 0xF8D626AAAF278509ULL }; + // Indices to the Random64[] array + const int PieceIdx = 0; + const int CastleIdx = 768; + const int EnPassantIdx = 772; + const int TurnIdx = 780; - /// Indices to the Random64[] array - - const int RandomPiece = 0; - const int RandomCastle = 768; - const int RandomEnPassant = 772; - const int RandomTurn = 780; - - - /// Prototypes - + // Local functions uint64_t book_key(const Position& pos); uint64_t book_piece_key(Piece p, Square s); uint64_t book_castle_key(const Position& pos); @@ -343,6 +330,13 @@ namespace { //// Functions //// +// C'tor. Make random number generation less deterministic, for book moves +Book::Book() { + + for (int i = abs(get_system_time() % 10000); i > 0; i--) + RKiss.rand(); +} + /// Destructor. Be sure file is closed before we leave. @@ -352,6 +346,16 @@ Book::~Book() { } +/// Book::close() closes the file only if it is open, otherwise +/// we can end up in a little mess due to how std::ifstream works. + +void Book::close() { + + if (is_open()) + ifstream::close(); +} + + /// Book::open() opens a book file with a given file name void Book::open(const string& fName) { @@ -361,32 +365,24 @@ void Book::open(const string& fName) { fileName = fName; ifstream::open(fileName.c_str(), ifstream::in | ifstream::binary); + + // Silently return when asked to open a non-exsistent file if (!is_open()) return; // Get the book size in number of entries seekg(0, ios::end); - bookSize = tellg() / EntrySize; + bookSize = long(tellg()) / EntrySize; seekg(0, ios::beg); if (!good()) { cerr << "Failed to open book file " << fileName << endl; - Application::exit_with_failure(); + exit(EXIT_FAILURE); } } -/// Book::close() closes the file only if it is open, otherwise -/// we can end up in a little mess due to how std::ifstream works. - -void Book::close() { - - if (is_open()) - ifstream::close(); -} - - /// Book::file_name() returns the file name of the currently active book, /// or the empty string if no book is open. @@ -399,14 +395,15 @@ const string Book::file_name() { // Not const to compile on HP-UX 11.X /// Book::get_move() gets a book move for a given position. Returns /// MOVE_NONE if no book move is found. -Move Book::get_move(const Position& pos) { +Move Book::get_move(const Position& pos, bool findBestMove) { if (!is_open() || bookSize == 0) return MOVE_NONE; - int bookMove = 0, scoresSum = 0; - uint64_t key = book_key(pos); BookEntry entry; + int bookMove = MOVE_NONE; + unsigned scoresSum = 0, bestScore = 0; + uint64_t key = book_key(pos); // Choose a book move among the possible moves for the given position for (int idx = find_key(key); idx < bookSize; idx++) @@ -415,24 +412,50 @@ Move Book::get_move(const Position& pos) { if (entry.key != key) break; - int score = entry.count; + unsigned score = entry.count; - assert(score > 0); + // If findBestMove is true choose highest rated book move + if (findBestMove) + { + if (score > bestScore) + { + bestScore = score; + bookMove = entry.move; + } + continue; + } // Choose book move according to its score. If a move has a very // high score it has more probability to be choosen then a one with // lower score. Note that first entry is always chosen. scoresSum += score; - if (int(genrand_int32() % scoresSum) < score) + if (RKiss.rand() % scoresSum < score) bookMove = entry.move; } if (!bookMove) return MOVE_NONE; - MoveStack mlist[256]; - MoveStack* last = generate_moves(pos, mlist); + // A PolyGlot book move is encoded as follows: + // + // bit 0- 5: destination square (from 0 to 63) + // bit 6-11: origin square (from 0 to 63) + // bit 12-13-14: promotion piece (from KNIGHT == 1 to QUEEN == 4) + // + // Castling moves follow "king captures rook" representation. So in case + // book move is a promotion we have to convert to our representation, in + // all other cases we can directly compare with a Move after having + // masked out special Move's flags that are not supported by PolyGlot. + int p = (bookMove >> 12) & 7; + + if (p) + bookMove = int(make_promotion_move(move_from(Move(bookMove)), + move_to(Move(bookMove)), PieceType(p + 1))); + + // Verify the book move is legal + MoveStack mlist[MOVES_MAX]; + MoveStack* last = generate(pos, mlist); for (MoveStack* cur = mlist; cur != last; cur++) - if ((int(cur->move) & 07777) == bookMove) + if ((int(cur->move) & ~(3 << 14)) == bookMove) // Mask out special flags return cur->move; return MOVE_NONE; @@ -462,6 +485,7 @@ int Book::find_key(uint64_t key) { assert(mid >= left && mid < right); read_entry(entry, mid); + if (key <= entry.key) right = mid; else @@ -471,7 +495,7 @@ int Book::find_key(uint64_t key) { assert(left == right); read_entry(entry, left); - return (entry.key == key)? left : bookSize; + return entry.key == key ? left : bookSize; } @@ -485,11 +509,13 @@ void Book::read_entry(BookEntry& entry, int idx) { assert(is_open()); seekg(idx * EntrySize, ios_base::beg); + *this >> entry; + if (!good()) { cerr << "Failed to read book entry at index " << idx << endl; - Application::exit_with_failure(); + exit(EXIT_FAILURE); } } @@ -500,10 +526,11 @@ void Book::read_entry(BookEntry& entry, int idx) { uint64_t Book::read_integer(int size) { char buf[8]; + uint64_t n = 0; + read(buf, size); // Numbers are stored on disk as a binary byte stream - uint64_t n = 0ULL; for (int i = 0; i < size; i++) n = (n << 8) + (unsigned char)buf[i]; @@ -519,23 +546,15 @@ namespace { uint64_t book_key(const Position& pos) { - uint64_t result = 0ULL; + uint64_t result = 0; + Bitboard b = pos.occupied_squares(); - for (Color c = WHITE; c <= BLACK; c++) + while (b) { - Bitboard b = pos.pieces_of_color(c); - - while (b) - { - Square s = pop_1st_bit(&b); - Piece p = pos.piece_on(s); - - assert(piece_is_ok(p)); - assert(color_of_piece(p) == c); - - result ^= book_piece_key(p, s); - } + Square s = pop_1st_bit(&b); + result ^= book_piece_key(pos.piece_on(s), s); } + result ^= book_castle_key(pos); result ^= book_ep_key(pos); result ^= book_color_key(pos); @@ -545,39 +564,41 @@ namespace { uint64_t book_piece_key(Piece p, Square s) { - /// Convert pieces to the range 0..11 + // Convert pieces to the range 0..11 static const int PieceTo12[] = { 0, 0, 2, 4, 6, 8, 10, 0, 0, 1, 3, 5, 7, 9, 11 }; - return Random64[RandomPiece + (PieceTo12[int(p)]^1) * 64 + int(s)]; + return Random64[PieceIdx + (PieceTo12[int(p)]^1) * 64 + int(s)]; } uint64_t book_castle_key(const Position& pos) { - uint64_t result = 0ULL; + uint64_t result = 0; if (pos.can_castle_kingside(WHITE)) - result ^= Random64[RandomCastle+0]; + result ^= Random64[CastleIdx + 0]; if (pos.can_castle_queenside(WHITE)) - result ^= Random64[RandomCastle+1]; + result ^= Random64[CastleIdx + 1]; if (pos.can_castle_kingside(BLACK)) - result ^= Random64[RandomCastle+2]; + result ^= Random64[CastleIdx + 2]; if (pos.can_castle_queenside(BLACK)) - result ^= Random64[RandomCastle+3]; + result ^= Random64[CastleIdx + 3]; return result; } uint64_t book_ep_key(const Position& pos) { - return (pos.ep_square() == SQ_NONE ? 0ULL : Random64[RandomEnPassant + square_file(pos.ep_square())]); + + return pos.ep_square() == SQ_NONE ? 0 : Random64[EnPassantIdx + square_file(pos.ep_square())]; } uint64_t book_color_key(const Position& pos) { - return (pos.side_to_move() == WHITE ? Random64[RandomTurn] : 0ULL); + + return pos.side_to_move() == WHITE ? Random64[TurnIdx] : 0; } }