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"
+#include <iostream>
+#include "move.h"
+#include "types.h"
-////
-//// Types
-////
-/// The TTEntry class is the class of transposition table entries
+/// The TTEntry is the class of transposition table entries
///
-/// A TTEntry needs 96 bits to be stored
+/// 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 0-16: move
-/// bit 17-19: not used
-/// bit 20-22: value type
+/// 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, ValueType t, Depth d, Move m, int g, Value statV, Value kd) {
-
- key32 = k;
- data = (m & 0x1FFFF) | (t << 20) | (g << 23);
- value16 = int16_t(v);
- depth16 = int16_t(d);
- staticValue = int16_t(statV);
- kingDanger = int16_t(kd);
+ void save(uint32_t k, Value v, ValueType t, Depth d, Move m, int g, Value statV, Value statM) {
+
+ key32 = (uint32_t)k;
+ move16 = (uint16_t)m;
+ valueType = (uint8_t)t;
+ 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(data & 0x1FFFF); }
- Value value() const { return Value(value16); }
- ValueType type() const { return ValueType((data >> 20) & 7); }
- int generation() const { return data >> 23; }
- Value static_value() const { return Value(staticValue); }
- Value king_danger() const { return Value(kingDanger); }
+ uint32_t key() const { return key32; }
+ Depth depth() const { return (Depth)depth16; }
+ Move move() const { return (Move)move16; }
+ Value value() const { return (Value)value16; }
+ ValueType type() const { return (ValueType)valueType; }
+ 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;
- uint32_t data;
- int16_t value16;
- int16_t depth16;
- int16_t staticValue;
- int16_t kingDanger;
+ uint16_t move16;
+ uint8_t valueType, generation8;
+ int16_t value16, depth16, staticValue, staticMargin;
};
-/// This is the number of TTEntry slots for each position
+/// This is the number of TTEntry slots for each cluster
const int ClusterSize = 4;
-/// Each group of ClusterSize number of TTEntry form a TTCluster
-/// that is indexed by a single position key. TTCluster size must
-/// be not bigger then a cache line size, in case it is less then
-/// it should be padded to guarantee always aligned accesses.
+
+/// 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 TTEntry objects, and a few methods for writing new entries
-/// and reading new ones.
+/// 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, ValueType type, Depth d, Move m, Value statV, Value kingD);
- TTEntry* retrieve(const Key posKey) const;
+ TTEntry* probe(const Key posKey) const;
void new_search();
- void insert_pv(const Position& pos, Move pv[]);
- void extract_pv(const Position& pos, Move bestMove, Move pv[], const int PLY_MAX);
- int full() const;
TTEntry* first_entry(const Key posKey) const;
+ void refresh(const TTEntry* tte) const;
private:
- // Be sure 'writes' is at least one cache line away
- // from read only variables.
- unsigned char pad_before[64 - sizeof(unsigned)];
- unsigned writes; // heavy SMP read/write access here
- unsigned char pad_after[64];
-
size_t size;
TTCluster* entries;
- uint8_t generation;
+ 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 low 32 bits of the key
-/// are used to get the index in the table.
+/// 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;
+ 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);
+}
+
+
+/// A simple fixed size hash table used to store pawns and material
+/// configurations. It is basically just an array of Entry objects.
+/// Without cluster concept or overwrite policy.
+
+template<class Entry, int HashSize>
+struct SimpleHash {
+
+ typedef SimpleHash<Entry, HashSize> Base;
+
+ void init() {
+
+ if (entries)
+ return;
+
+ entries = new (std::nothrow) Entry[HashSize];
+ if (!entries)
+ {
+ std::cerr << "Failed to allocate " << HashSize * sizeof(Entry)
+ << " bytes for hash table." << std::endl;
+ exit(EXIT_FAILURE);
+ }
+ memset(entries, 0, HashSize * sizeof(Entry));
+ }
+
+ virtual ~SimpleHash() { delete [] entries; }
+
+ Entry* probe(Key key) const { return entries + ((uint32_t)key & (HashSize - 1)); }
+ void prefetch(Key key) const { ::prefetch((char*)probe(key)); }
+
+protected:
+ Entry* entries;
+};
+
#endif // !defined(TT_H_INCLUDED)