/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008 Marco Costalba
+ Copyright (C) 2008-2010 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
#if !defined(TT_H_INCLUDED)
#define TT_H_INCLUDED
-////
-//// Includes
-////
+#include <iostream>
#include "depth.h"
-#include "position.h"
+#include "move.h"
#include "value.h"
//// Types
////
-/// The TTEntry class is the class of transposition table entries.
+
+/// 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 + ((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
+///
+/// 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:
- TTEntry();
- TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation);
- Key key() const { return key_; }
- Depth depth() const { return Depth(depth_); }
- Move move() const { return Move(data & 0x1FFFF); }
- Value value() const { return Value(value_); }
- ValueType type() const { return ValueType((data >> 20) & 7); }
- int generation() const { return (data >> 23); }
+ 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(move16); }
+ Value value() const { return Value(value16); }
+ 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(staticMargin); }
private:
- Key key_;
- uint32_t data;
- int16_t value_;
- int16_t depth_;
+ uint32_t key32;
+ uint16_t move16;
+ uint8_t valueType;
+ uint8_t generation8;
+ int16_t value16;
+ int16_t depth16;
+ int16_t staticValue;
+ int16_t staticMargin;
};
-/// The transposition table class. This is basically just a huge array
-/// containing TTEntry objects, and a few methods for writing new entries
+
+/// 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 new entries
/// and reading new ones.
class TranspositionTable {
+ TranspositionTable(const TranspositionTable&);
+ TranspositionTable& operator=(const TranspositionTable&);
+
public:
- TranspositionTable(unsigned mbSize);
+ TranspositionTable();
~TranspositionTable();
- void set_size(unsigned mbSize);
+ void set_size(size_t mbSize);
void clear();
- void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
- TTEntry* retrieve(const Position &pos) const;
+ 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[]);
- int full();
+ TTEntry* first_entry(const Key posKey) const;
+ void refresh(const TTEntry* tte) const;
private:
- inline TTEntry* first_entry(const Position &pos) const;
-
- unsigned size;
- int writes;
- TTEntry* entries;
- uint8_t generation;
+ size_t size;
+ TTCluster* entries;
+ uint8_t generation; // To properly compare, size must be smaller then TT stored value
};
+extern TranspositionTable TT;
-////
-//// Constants and variables
-////
-// Default transposition table size, in megabytes:
-const int TTDefaultSize = 32;
+/// 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, 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