/*
- 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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
- 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.
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
#if !defined(TT_H_INCLUDED)
#define TT_H_INCLUDED
-////
-//// Includes
-////
-
-#include "depth.h"
-#include "position.h"
-#include "value.h"
-
-
-////
-//// Types
-////
-
-/// The TTEntry class is the class of transposition table entries.
+#include "misc.h"
+#include "types.h"
+
+/// The TTEntry is the class of transposition table entries
+///
+/// A TTEntry needs 128 bits to be stored
+///
+/// bit 0-31: key
+/// bit 32-63: data
+/// bit 64-79: value
+/// bit 80-95: depth
+/// bit 96-111: static value
+/// bit 112-127: margin of static value
+///
+/// the 32 bits of the data field are so defined
+///
+/// bit 0-15: move
+/// bit 16-20: not used
+/// bit 21-22: 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 { return key_; }
- Depth depth() const { return Depth(depth_); }
- Move move() const { return Move(data & 0x7FFFF); }
- Value value() const { return Value(value_); }
- ValueType type() const { return ValueType((data >> 20) & 3); }
- int generation() const { return (data >> 23); }
+ void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value ev, Value em) {
+
+ key32 = (uint32_t)k;
+ move16 = (uint16_t)m;
+ bound = (uint8_t)b;
+ generation8 = (uint8_t)g;
+ value16 = (int16_t)v;
+ depth16 = (int16_t)d;
+ evalValue = (int16_t)ev;
+ evalMargin = (int16_t)em;
+ }
+ void set_generation(int g) { generation8 = (uint8_t)g; }
+
+ uint32_t key() const { return key32; }
+ Depth depth() const { return (Depth)depth16; }
+ Move move() const { return (Move)move16; }
+ Value value() const { return (Value)value16; }
+ Bound type() const { return (Bound)bound; }
+ int generation() const { return (int)generation8; }
+ Value eval_value() const { return (Value)evalValue; }
+ Value eval_margin() const { return (Value)evalMargin; }
private:
- Key key_;
- uint32_t data;
- int16_t value_;
- int16_t depth_;
+ uint32_t key32;
+ uint16_t move16;
+ uint8_t bound, generation8;
+ int16_t value16, depth16, evalValue, evalMargin;
};
-/// 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.
+
+/// A TranspositionTable consists of a power of 2 number of clusters and each
+/// cluster consists of ClusterSize number of TTEntry. Each non-empty entry
+/// contains information of exactly one position. Size of a cluster shall not be
+/// bigger than a cache line size. In case it is less, it should be padded to
+/// guarantee always aligned accesses.
class TranspositionTable {
+ static const unsigned ClusterSize = 4; // A cluster is 64 Bytes
+
public:
- TranspositionTable(unsigned mbSize);
- ~TranspositionTable();
- void set_size(unsigned mbSize);
+ ~TranspositionTable() { free(mem); }
+ void new_search() { generation++; }
+
+ TTEntry* probe(const Key key) const;
+ TTEntry* first_entry(const Key key) const;
+ void refresh(const TTEntry* tte) const;
+ void set_size(size_t mbSize);
void clear();
- void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
- const TTEntry* retrieve(const Position &pos) const;
- void new_search();
- void insert_pv(const Position &pos, Move pv[]);
- int full();
+ void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV, Value kingD);
private:
- TTEntry* first_entry(const Position &pos) const;
-
- unsigned size;
- int writes;
- TTEntry* entries;
- uint8_t generation;
+ uint32_t hashMask;
+ TTEntry* table;
+ void* mem;
+ uint8_t generation; // Size must be not bigger then TTEntry::generation8
};
+extern TranspositionTable TT;
+
+
+/// TranspositionTable::first_entry() returns a pointer to the first entry of
+/// a cluster given a position. The lowest order bits of the key are used to
+/// get the index of the cluster.
+
+inline TTEntry* TranspositionTable::first_entry(const Key key) const {
+
+ return table + ((uint32_t)key & hashMask);
+}
+
-////
-//// Constants and variables
-////
+/// TranspositionTable::refresh() updates the 'generation' value of the TTEntry
+/// to avoid aging. Normally called after a TT hit.
-// Default transposition table size, in megabytes:
-const int TTDefaultSize = 32;
+inline void TranspositionTable::refresh(const TTEntry* tte) const {
+ const_cast<TTEntry*>(tte)->set_generation(generation);
+}
#endif // !defined(TT_H_INCLUDED)
projects / stockfish / blobdiff