/*
- Glaurung, a UCI chess playing engine.
- Copyright (C) 2004-2008 Tord Romstad
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008 Marco Costalba
- Glaurung is free software: you can redistribute it and/or modify
+ Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
- Glaurung is distributed in the hope that it will be useful,
+ Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
//// Types
////
-/// The TTEntry class is the class of transposition table entries.
+/// The TTEntry class is the class of transposition table entries
+///
+/// A TTEntry needs 128 bits to be stored
+///
+/// bit 0-63: key
+/// bit 64-95: data
+/// bit 96-111: value
+/// bit 112-127: depth
+///
+/// the 32 bits of the data field are so defined
+///
+/// bit 0-16: move
+/// bit 17-19: not used
+/// bit 20-22: value type
+/// bit 23-31: generation
class TTEntry {
public:
- TTEntry();
- TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation);
- Key key() const;
- Depth depth() const;
- Move move() const;
- Value value() const;
- ValueType type() const;
- int generation() const;
+ TTEntry() {}
+ TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation)
+ : key_ (k), data((m & 0x1FFFF) | (t << 20) | (generation << 23)),
+ value_(int16_t(v)), depth_(int16_t(d)) {}
+
+ Key key() const { return key_; }
+ Depth depth() const { return Depth(depth_); }
+ Move move() const { return Move(data & 0x1FFFF); }
+ Value value() const { return Value(value_); }
+ ValueType type() const { return ValueType((data >> 20) & 7); }
+ int generation() const { return (data >> 23); }
private:
Key key_;
int16_t depth_;
};
-
/// The transposition table class. This is basically just a huge array
/// containing TTEntry objects, and a few methods for writing new entries
/// and reading new ones.
class TranspositionTable {
public:
- TranspositionTable(unsigned mbSize);
+ TranspositionTable();
~TranspositionTable();
void set_size(unsigned mbSize);
void clear();
- void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
- bool retrieve(const Position &pos, Value *value, Depth *d, Move *move,
- ValueType *type) const;
+ void store(const Key posKey, Value v, ValueType type, Depth d, Move m);
+ TTEntry* retrieve(const Key posKey) const;
void new_search();
- void insert_pv(const Position &pos, Move pv[]);
- int full();
+ void insert_pv(const Position& pos, Move pv[]);
+ int full() const;
private:
- TTEntry* first_entry(const Position &pos) const;
+ inline TTEntry* first_entry(const Key posKey) const;
- unsigned size;
- int writes;
+ unsigned size, writes;
TTEntry* entries;
uint8_t generation;
};
-
-////
-//// Constants and variables
-////
-
-// Default transposition table size, in megabytes:
-const int TTDefaultSize = 32;
-
-
#endif // !defined(TT_H_INCLUDED)