From: Marco Costalba Date: Sat, 5 Jan 2013 14:24:18 +0000 (+0100) Subject: Have fun with union in book.cpp X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=9b1cf3cf4360278f5485db6ba81c2cfeae746bd7 Have fun with union in book.cpp Fancy way to use an union to map polyglot zobrist keys in one go. Also some renaming while there. No functional change. --- diff --git a/src/book.cpp b/src/book.cpp index d75d63f9..37cfe8f5 100644 --- a/src/book.cpp +++ b/src/book.cpp @@ -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, @@ -308,47 +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() : RKiss(Time::now() % 10000) {} +PolyglotBook::PolyglotBook() : rkiss(Time::now() % 10000) {} PolyglotBook::~PolyglotBook() { if (is_open()) close(); } @@ -366,7 +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; } @@ -396,13 +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()) { @@ -412,7 +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); } @@ -447,12 +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); @@ -462,7 +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) diff --git a/src/book.h b/src/book.h index fcbce65b..40a8bad2 100644 --- a/src/book.h +++ b/src/book.h @@ -36,9 +36,9 @@ private: template PolyglotBook& operator>>(T& n); bool open(const char* fName); - size_t find_first(uint64_t key); + size_t find_first(Key key); - RKISS RKiss; + RKISS rkiss; std::string fileName; }; diff --git a/src/endgame.h b/src/endgame.h index 78b31d82..47ff6d19 100644 --- a/src/endgame.h +++ b/src/endgame.h @@ -112,7 +112,7 @@ class Endgames { public: Endgames(); - ~Endgames(); + ~Endgames(); template T probe(Key key, T& eg) { return eg = map(eg).count(key) ? map(eg)[key] : NULL; } diff --git a/src/tt.h b/src/tt.h index 3edd5e8a..f3b0f2ad 100644 --- a/src/tt.h +++ b/src/tt.h @@ -97,7 +97,7 @@ class TranspositionTable { public: TranspositionTable(); - ~TranspositionTable(); + ~TranspositionTable(); void set_size(size_t mbSize); void clear(); void store(const Key posKey, Value v, Bound type, Depth d, Move m, Value statV, Value kingD);