////
#include "depth.h"
-#include "position.h"
+#include "move.h"
#include "value.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 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 + unsigned(key & (HashSize - 1)); }
+
+protected:
+ Entry* entries;
+};
+
+
/// The TTEntry class 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 17-20: not used
+/// bit 21-22: value type
/// bit 23-31: generation
class TTEntry {
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);
+ data = (m & 0x1FFFF) | (t << 21) | (g << 23);
+ value16 = (int16_t)v;
+ depth16 = (int16_t)d;
+ staticValue = (int16_t)statV;
+ staticValueMargin = (int16_t)kd;
}
+ void set_generation(int g) { data = move() | (type() << 21) | (g << 23); }
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); }
+ ValueType type() const { return ValueType((data >> 21) & 3); }
int generation() const { return data >> 23; }
Value static_value() const { return Value(staticValue); }
- Value king_danger() const { return Value(kingDanger); }
+ Value static_value_margin() const { return Value(staticValueMargin); }
private:
uint32_t key32;
int16_t value16;
int16_t depth16;
int16_t staticValue;
- int16_t kingDanger;
+ int16_t staticValueMargin;
};
-/// 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
+/// containing TTCluster objects, and a few methods for writing new entries
/// and reading new ones.
class TranspositionTable {
+ TranspositionTable(const TranspositionTable&);
+ TranspositionTable& operator=(const TranspositionTable&);
+
public:
TranspositionTable();
~TranspositionTable();
void store(const Key posKey, Value v, ValueType type, Depth d, Move m, Value statV, Value kingD);
TTEntry* retrieve(const Key posKey) const;
void new_search();
- void insert_pv(const Position& pos, Move pv[]);
- void extract_pv(const Position& pos, 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; // To properly compare, size must be smaller then TT stored value
};
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.
+/// 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, before to return.
+
+inline void TranspositionTable::refresh(const TTEntry* tte) const {
+
+ const_cast<TTEntry*>(tte)->set_generation(generation);
}
#endif // !defined(TT_H_INCLUDED)
projects / stockfish / blobdiff