mirror of
https://github.com/peterosterlund2/droidfish.git
synced 2025-01-08 08:17:01 +01:00
137 lines
4.1 KiB
C++
137 lines
4.1 KiB
C++
/*
|
|
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
|
|
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
|
|
Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
|
|
|
|
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.
|
|
|
|
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.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#if !defined(TT_H_INCLUDED)
|
|
#define TT_H_INCLUDED
|
|
|
|
#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:
|
|
void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value statV, Value statM) {
|
|
|
|
key32 = (uint32_t)k;
|
|
move16 = (uint16_t)m;
|
|
bound = (uint8_t)b;
|
|
generation8 = (uint8_t)g;
|
|
value16 = (int16_t)v;
|
|
depth16 = (int16_t)d;
|
|
staticValue = (int16_t)statV;
|
|
staticMargin = (int16_t)statM;
|
|
}
|
|
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 static_value() const { return (Value)staticValue; }
|
|
Value static_value_margin() const { return (Value)staticMargin; }
|
|
|
|
private:
|
|
uint32_t key32;
|
|
uint16_t move16;
|
|
uint8_t bound, generation8;
|
|
int16_t value16, depth16, staticValue, staticMargin;
|
|
};
|
|
|
|
|
|
/// This is the number of TTEntry slots for each cluster
|
|
const int ClusterSize = 4;
|
|
|
|
|
|
/// TTCluster consists of ClusterSize number of TTEntries. Size of TTCluster
|
|
/// must not be bigger than a cache line size. In case it is less, it should
|
|
/// be padded to guarantee always aligned accesses.
|
|
|
|
struct TTCluster {
|
|
TTEntry data[ClusterSize];
|
|
};
|
|
|
|
|
|
/// The transposition table class. This is basically just a huge array containing
|
|
/// TTCluster objects, and a few methods for writing and reading entries.
|
|
|
|
class TranspositionTable {
|
|
|
|
TranspositionTable(const TranspositionTable&);
|
|
TranspositionTable& operator=(const TranspositionTable&);
|
|
|
|
public:
|
|
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);
|
|
TTEntry* probe(const Key posKey) const;
|
|
void new_search();
|
|
TTEntry* first_entry(const Key posKey) const;
|
|
void refresh(const TTEntry* tte) const;
|
|
|
|
private:
|
|
size_t size;
|
|
TTCluster* entries;
|
|
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 posKey) const {
|
|
|
|
return entries[((uint32_t)posKey) & (size - 1)].data;
|
|
}
|
|
|
|
|
|
/// TranspositionTable::refresh() updates the 'generation' value of the TTEntry
|
|
/// to avoid aging. Normally called after a TT hit.
|
|
|
|
inline void TranspositionTable::refresh(const TTEntry* tte) const {
|
|
|
|
const_cast<TTEntry*>(tte)->set_generation(generation);
|
|
}
|
|
|
|
#endif // !defined(TT_H_INCLUDED)
|