mirror of
https://github.com/peterosterlund2/droidfish.git
synced 2024-12-05 01:35:50 +01:00
117 lines
3.5 KiB
C++
117 lines
3.5 KiB
C++
/*
|
|
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
|
|
|
|
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/>.
|
|
*/
|
|
|
|
#ifndef TT_H_INCLUDED
|
|
#define TT_H_INCLUDED
|
|
|
|
#include "misc.h"
|
|
#include "types.h"
|
|
|
|
/// The TTEntry is the 128 bit transposition table entry, defined as below:
|
|
///
|
|
/// key: 32 bit
|
|
/// move: 16 bit
|
|
/// bound type: 8 bit
|
|
/// generation: 8 bit
|
|
/// value: 16 bit
|
|
/// depth: 16 bit
|
|
/// static value: 16 bit
|
|
/// static margin: 16 bit
|
|
|
|
struct TTEntry {
|
|
|
|
void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value ev) {
|
|
|
|
key32 = (uint32_t)k;
|
|
move16 = (uint16_t)m;
|
|
bound8 = (uint8_t)b;
|
|
generation8 = (uint8_t)g;
|
|
value16 = (int16_t)v;
|
|
depth16 = (int16_t)d;
|
|
evalValue = (int16_t)ev;
|
|
}
|
|
void set_generation(uint8_t g) { generation8 = 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 bound() const { return (Bound)bound8; }
|
|
int generation() const { return (int)generation8; }
|
|
Value eval_value() const { return (Value)evalValue; }
|
|
|
|
private:
|
|
uint32_t key32;
|
|
uint16_t move16;
|
|
uint8_t bound8, generation8;
|
|
int16_t value16, depth16, evalValue;
|
|
};
|
|
|
|
|
|
/// 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() { free(mem); }
|
|
void new_search() { ++generation; }
|
|
|
|
const 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 Key key, Value v, Bound type, Depth d, Move m, Value statV);
|
|
|
|
private:
|
|
uint32_t hashMask;
|
|
TTEntry* table;
|
|
void* mem;
|
|
uint8_t generation; // Size must be not bigger than 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);
|
|
}
|
|
|
|
|
|
/// 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 // #ifndef TT_H_INCLUDED
|