#if !defined(TT_H_INCLUDED)
#define TT_H_INCLUDED
-////
-//// Includes
-////
+#include <iostream>
#include "depth.h"
#include "move.h"
//// Types
////
+
+/// 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>
+class SimpleHash {
+
+ SimpleHash(const SimpleHash&);
+ SimpleHash& operator=(const SimpleHash&);
+
+public:
+ SimpleHash() {
+
+ entries = new (std::nothrow) Entry[HashSize];
+ if (!entries)
+ {
+ std::cerr << "Failed to allocate " << HashSize * sizeof(Entry)
+ << " bytes for material hash table." << std::endl;
+ exit(EXIT_FAILURE);
+ }
+ memset(entries, 0, HashSize * sizeof(Entry));
+ }
+
+ ~SimpleHash() { delete [] entries; }
+
+ Entry* find(Key key) const { return entries + ((uint32_t)key & (HashSize - 1)); }
+
+protected:
+ Entry* entries;
+};
+
+
/// The TTEntry class is the class of transposition table entries
///
/// A TTEntry needs 128 bits to be stored
///
/// the 32 bits of the data field are so defined
///
-/// bit 0-16: move
-/// bit 17-20: not used
+/// 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 << 21) | (g << 23);
- value16 = int16_t(v);
- depth16 = int16_t(d);
- staticValue = int16_t(statV);
- staticValueMargin = 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); }
+ Move move() const { return Move(move16); }
Value value() const { return Value(value16); }
- ValueType type() const { return ValueType((data >> 21) & 3); }
- int generation() const { return data >> 23; }
+ ValueType type() const { return ValueType(valueType); }
+ int generation() const { return generation8; }
Value static_value() const { return Value(staticValue); }
- Value static_value_margin() const { return Value(staticValueMargin); }
+ Value static_value_margin() const { return Value(staticMargin); }
private:
uint32_t key32;
- uint32_t data;
+ uint16_t move16;
+ uint8_t valueType;
+ uint8_t generation8;
int16_t value16;
int16_t depth16;
int16_t staticValue;
- int16_t staticValueMargin;
+ int16_t staticMargin;
};
class TranspositionTable {
+ TranspositionTable(const TranspositionTable&);
+ TranspositionTable& operator=(const TranspositionTable&);
+
public:
TranspositionTable();
~TranspositionTable();
TTEntry* retrieve(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;
+ uint8_t generation; // To properly compare, size must be smaller then TT stored value
};
extern TranspositionTable TT;
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, before to return.
+
+inline void TranspositionTable::refresh(const TTEntry* tte) const {
+
+ const_cast<TTEntry*>(tte)->set_generation(generation);
}
#endif // !defined(TT_H_INCLUDED)