2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008 Marco Costalba
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #if !defined(TT_H_INCLUDED)
37 /// The TTEntry class is the class of transposition table entries
39 /// A TTEntry needs 128 bits to be stored
44 /// bit 112-127: depth
46 /// the 32 bits of the data field are so defined
49 /// bit 17-19: not used
50 /// bit 20-22: value type
51 /// bit 23-31: generation
57 TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation);
58 Key key() const { return key_; }
59 Depth depth() const { return Depth(depth_); }
60 Move move() const { return Move(data & 0x1FFFF); }
61 Value value() const { return Value(value_); }
62 ValueType type() const { return ValueType((data >> 20) & 7); }
63 int generation() const { return (data >> 23); }
72 /// The transposition table class. This is basically just a huge array
73 /// containing TTEntry objects, and a few methods for writing new entries
74 /// and reading new ones.
76 class TranspositionTable {
79 TranspositionTable(unsigned mbSize);
80 ~TranspositionTable();
81 void set_size(unsigned mbSize);
83 void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
84 TTEntry* retrieve(const Position &pos) const;
86 void insert_pv(const Position &pos, Move pv[]);
90 inline TTEntry* first_entry(const Position &pos) const;
100 //// Constants and variables
103 // Default transposition table size, in megabytes:
104 const int TTDefaultSize = 32;
107 #endif // !defined(TT_H_INCLUDED)