/*
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) 2008-2012 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
#if !defined(TT_H_INCLUDED)
#define TT_H_INCLUDED
-////
-//// Includes
-////
+#include "misc.h"
+#include "types.h"
+
+/// The TTEntry 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
-#include "depth.h"
-#include "position.h"
-#include "value.h"
+class TTEntry {
+public:
+ void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g) {
+
+ key32 = (uint32_t)k;
+ move16 = (uint16_t)m;
+ bound = (uint8_t)b;
+ generation8 = (uint8_t)g;
+ valueUpper = (int16_t)(b & BOUND_UPPER ? v : VALUE_NONE);
+ depthUpper = (int16_t)(b & BOUND_UPPER ? d : DEPTH_NONE);
+ valueLower = (int16_t)(b & BOUND_LOWER ? v : VALUE_NONE);
+ depthLower = (int16_t)(b & BOUND_LOWER ? d : DEPTH_NONE);
+ }
+
+ void update(Value v, Bound b, Depth d, Move m, int g) {
+
+ move16 = (uint16_t)m;
+ generation8 = (uint8_t)g;
+
+ if (bound == BOUND_EXACT)
+ bound = BOUND_UPPER | BOUND_LOWER; // Drop 'EXACT' flag
+
+ if (b & BOUND_UPPER)
+ {
+ valueUpper = (int16_t)v;
+ depthUpper = (int16_t)d;
+
+ if ((bound & BOUND_LOWER) && v < valueLower)
+ {
+ bound ^= BOUND_LOWER;
+ valueLower = VALUE_NONE;
+ depthLower = DEPTH_NONE;
+ }
+ }
+
+ if (b & BOUND_LOWER)
+ {
+ valueLower = (int16_t)v;
+ depthLower = (int16_t)d;
+
+ if ((bound & BOUND_UPPER) && v > valueUpper)
+ {
+ bound ^= BOUND_UPPER;
+ valueUpper = VALUE_NONE;
+ depthUpper = DEPTH_NONE;
+ }
+ }
+
+ bound |= (uint8_t)b;
+ }
+
+ void set_generation(int g) { generation8 = (uint8_t)g; }
+
+ uint32_t key() const { return key32; }
+ Depth depth() const { return (Depth)depthLower; }
+ Depth depth_upper() const { return (Depth)depthUpper; }
+ Move move() const { return (Move)move16; }
+ Value value() const { return (Value)valueLower; }
+ Value value_upper() const { return (Value)valueUpper; }
+ Bound type() const { return (Bound)bound; }
+ int generation() const { return (int)generation8; }
-////
-//// Types
-////
+private:
+ uint32_t key32;
+ uint16_t move16;
+ uint8_t bound, generation8;
+ int16_t valueLower, depthLower, valueUpper, depthUpper;
+};
-/// The TTEntry class is the class of transposition table entries.
-class TTEntry {
+/// This is the number of TTEntry slots for each cluster
+const int ClusterSize = 4;
-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); }
-private:
- Key key_;
- uint32_t data;
- int16_t value_;
- int16_t depth_;
+/// 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(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, Bound b, Depth d, Move m);
+ TTEntry* probe(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; // 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 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;
+}
+
-////
-//// Constants and variables
-////
+/// TranspositionTable::refresh() updates the 'generation' value of the TTEntry
+/// to avoid aging. Normally called after a TT hit.
-// Default transposition table size, in megabytes:
-const int TTDefaultSize = 32;
+inline void TranspositionTable::refresh(const TTEntry* tte) const {
+ const_cast<TTEntry*>(tte)->set_generation(generation);
+}
#endif // !defined(TT_H_INCLUDED)
projects / stockfish / blobdiff