X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbook.cpp;h=494c9c1121cfca0af4410ab249d7bd1c0b5e6456;hp=091767b3ae7c566ee691f1b44f0c3549d8ee52ac;hb=c2d42ea8339b49e52a116e488214a14fda09d413;hpb=9bee5f51d811fb5c2e11a94b4e111a69b87855a2 diff --git a/src/book.cpp b/src/book.cpp index 091767b3..494c9c11 100644 --- a/src/book.cpp +++ b/src/book.cpp @@ -28,6 +28,7 @@ #include #include "book.h" +#include "misc.h" #include "movegen.h" using namespace std; @@ -35,7 +36,7 @@ using namespace std; namespace { // Random numbers from PolyGlot, used to compute book hash keys - const uint64_t Random64[781] = { + const Key PolyGlotRandoms[781] = { 0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL, 0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL, 0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL, 0x0D7E765D58755C10ULL, @@ -299,57 +300,56 @@ namespace { 0xF8D626AAAF278509ULL }; - // Indices to the Random64[] array - const int PieceIdx = 0; - const int CastleIdx = 768; - const int EnPassantIdx = 772; - const int TurnIdx = 780; + // Offsets to the PolyGlotRandoms[] array of zobrist keys + const Key* ZobPiece = PolyGlotRandoms + 0; + const Key* ZobCastle = PolyGlotRandoms + 768; + const Key* ZobEnPassant = PolyGlotRandoms + 772; + const Key* ZobTurn = PolyGlotRandoms + 780; + + // Piece offset is calculated as 64 * (PolyPiece ^ 1) where + // PolyPiece is: BP = 0, WP = 1, BN = 2, WN = 3 ... BK = 10, WK = 11 + const int PieceOfs[] = { 0, 64, 192, 320, 448, 576, 704, 0, + 0, 0, 128, 256, 384, 512, 640 }; // book_key() builds up a PolyGlot hash key out of a position uint64_t book_key(const Position& pos) { - // Piece offset is calculated as (64 * PolyPieceType + square), where - // PolyPieceType is: BP = 0, WP = 1, BN = 2, WN = 3 .... BK = 10, WK = 11 - static const int PieceToPoly[] = { 0, 1, 3, 5, 7, 9, 11, 0, 0, 0, 2, 4, 6, 8, 10 }; - uint64_t result = 0; Bitboard b = pos.occupied_squares(); while (b) { Square s = pop_1st_bit(&b); - int p = PieceToPoly[int(pos.piece_on(s))]; - result ^= Random64[PieceIdx + 64 * p + int(s)]; + result ^= ZobPiece[PieceOfs[pos.piece_on(s)] + s]; } - if (pos.can_castle_kingside(WHITE)) - result ^= Random64[CastleIdx + 0]; + if (pos.can_castle(WHITE_OO)) + result ^= ZobCastle[0]; - if (pos.can_castle_queenside(WHITE)) - result ^= Random64[CastleIdx + 1]; + if (pos.can_castle(WHITE_OOO)) + result ^= ZobCastle[1]; - if (pos.can_castle_kingside(BLACK)) - result ^= Random64[CastleIdx + 2]; + if (pos.can_castle(BLACK_OO)) + result ^= ZobCastle[2]; - if (pos.can_castle_queenside(BLACK)) - result ^= Random64[CastleIdx + 3]; + if (pos.can_castle(BLACK_OOO)) + result ^= ZobCastle[3]; if (pos.ep_square() != SQ_NONE) - result ^= Random64[EnPassantIdx + square_file(pos.ep_square())]; + result ^= ZobEnPassant[file_of(pos.ep_square())]; if (pos.side_to_move() == WHITE) - result ^= Random64[TurnIdx]; + result ^= ZobTurn[0]; return result; } - } /// Book c'tor. Make random number generation less deterministic, for book moves -Book::Book() { +Book::Book() : bookSize(0) { - for (int i = abs(get_system_time() % 10000); i > 0; i--) + for (int i = abs(system_time() % 10000); i > 0; i--) RKiss.rand(); } @@ -362,8 +362,8 @@ 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. +/// Book::close() closes the file only if it is open, otherwise the call fails +/// and the failbit internal state flag is set. void Book::close() { @@ -371,24 +371,24 @@ void Book::close() { bookFile.close(); bookName = ""; + bookSize = 0; } -/// Book::open() opens a book file with a given file name +/// Book::open() opens a book file with a given name void Book::open(const string& fileName) { // Close old file before opening the new close(); - bookFile.open(fileName.c_str(), ifstream::in | ifstream::binary); + bookFile.open(fileName.c_str(), ifstream::in | ifstream::binary |ios::ate); // Silently return when asked to open a non-exsistent file if (!bookFile.is_open()) return; - // Get the book size in number of entries - bookFile.seekg(0, ios::end); + // Get the book size in number of entries, we are already at the file end bookSize = long(bookFile.tellg()) / sizeof(BookEntry); if (!bookFile.good()) @@ -402,46 +402,39 @@ void Book::open(const string& fileName) { } -/// Book::get_move() gets a book move for a given position. Returns -/// MOVE_NONE if no book move is found. If findBestMove is true then -/// return always the highest rated book move. +/// Book::probe() gets a book move for a given position. Returns MOVE_NONE +/// if no book move is found. If findBest is true then returns always the +/// highest rated move otherwise chooses randomly based on the move score. -Move Book::get_move(const Position& pos, bool findBestMove) { +Move Book::probe(const Position& pos, bool findBest) { - if (!bookFile.is_open() || bookSize == 0) + if (!bookSize || !bookFile.is_open()) return MOVE_NONE; BookEntry entry; - int bookMove = MOVE_NONE; - unsigned score, scoresSum = 0, bestScore = 0; + unsigned scoresSum = 0, bestScore = 0, bookMove = 0; uint64_t key = book_key(pos); + int idx = first_entry(key) - 1; // Choose a book move among the possible moves for the given position - for (int idx = find_entry(key); idx < bookSize; idx++) + while (++idx < bookSize && (entry = read_entry(idx), entry.key == key)) { - entry = read_entry(idx); - - if (entry.key != key) - break; - - score = entry.count; - - if (!findBestMove) - { - // 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 (RKiss.rand() % scoresSum < score) - bookMove = entry.move; - } - else if (score > bestScore) - { - bestScore = score; + scoresSum += entry.count; + + // 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 ( RKiss.rand() % scoresSum < entry.count + || (findBest && entry.count > bestScore)) bookMove = entry.move; - } + + if (entry.count > bestScore) + bestScore = entry.count; } + if (!bookMove) + return MOVE_NONE; + // A PolyGlot book move is encoded as follows: // // bit 0- 5: destination square (from 0 to 63) @@ -452,33 +445,31 @@ Move Book::get_move(const Position& pos, bool findBestMove) { // 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; + int promotion = (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 (if any) is legal - MoveStack mlist[MOVES_MAX]; - MoveStack* last = generate(pos, mlist); - for (MoveStack* cur = mlist; cur != last; cur++) - if ((int(cur->move) & ~(3 << 14)) == bookMove) // Mask out special flags - return cur->move; + if (promotion) + bookMove = make_promotion_move(move_from(Move(bookMove)), + move_to(Move(bookMove)), + PieceType(promotion + 1)); + // Verify the book move is legal + for (MoveList ml(pos); !ml.end(); ++ml) + if (unsigned(ml.move() & ~(3 << 14)) == bookMove) // Mask out special flags + return ml.move(); return MOVE_NONE; } -/// Book::find_entry() takes a book key as input, and does a binary search -/// through the book file for the given key. The index to the first book -/// entry with the same key as the input is returned. When the key is not +/// Book::first_entry() takes a book key as input, and does a binary search +/// through the book file for the given key. The index to the first (leftmost) +/// book entry with the same key as the input is returned. When the key is not /// found in the book file, bookSize is returned. -int Book::find_entry(uint64_t key) { +int Book::first_entry(uint64_t key) { int left, right, mid; - // Binary search (finds the leftmost entry) + // Binary search (finds the leftmost entry with given key) left = 0; right = bookSize - 1; @@ -502,6 +493,20 @@ int Book::find_entry(uint64_t key) { } +/// Book::operator>>() reads sizeof(T) chars from the file's binary byte +/// stream and converts them in a number of type T. +template +Book& Book::operator>>(T& n) { + + n = 0; + + for (size_t i = 0; i < sizeof(T); i++) + n = T((n << 8) + bookFile.get()); + + return *this; +} + + /// Book::read_entry() takes an integer index, and returns the BookEntry /// at the given index in the book file.