X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.h;h=3113751adb938e868616efe6a8eb78c15e946b43;hp=02913efe7f66f0bd1a162de084bdbf1b54cb4a38;hb=45b0aea875860e9f0fe2d0435ee6163906639194;hpb=5a0581498cde3d0904924d8ef7ed25ea1a2c855a

diff --git a/src/tt.h b/src/tt.h
index 02913efe..3113751a 100644
--- a/src/tt.h
+++ b/src/tt.h
@@ -1,7 +1,7 @@
 /*
   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) 2008-2013 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
@@ -17,77 +17,102 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
-#if !defined(TT_H_INCLUDED)
+#ifndef TT_H_INCLUDED
 #define TT_H_INCLUDED
 
-////
-//// Includes
-////
+#include "misc.h"
+#include "types.h"
+
+/// The TTEntry is the 128 bit transposition table entry, defined as below:
+///
+/// key: 32 bit
+/// move: 16 bit
+/// bound type: 8 bit
+/// generation: 8 bit
+/// value: 16 bit
+/// depth: 16 bit
+/// static value: 16 bit
+/// static margin: 16 bit
+
+struct TTEntry {
+
+  void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value ev, Value em) {
+
+    key32        = (uint32_t)k;
+    move16       = (uint16_t)m;
+    bound8       = (uint8_t)b;
+    generation8  = (uint8_t)g;
+    value16      = (int16_t)v;
+    depth16      = (int16_t)d;
+    evalValue    = (int16_t)ev;
+    evalMargin   = (int16_t)em;
+  }
+  void set_generation(uint8_t g) { generation8 = 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; }
+  Bound bound() const       { return (Bound)bound8; }
+  int generation() const    { return (int)generation8; }
+  Value eval_value() const  { return (Value)evalValue; }
+  Value eval_margin() const { return (Value)evalMargin; }
 
-#include "depth.h"
-#include "position.h"
-#include "value.h"
+private:
+  uint32_t key32;
+  uint16_t move16;
+  uint8_t bound8, generation8;
+  int16_t value16, depth16, evalValue, evalMargin;
+};
 
 
-////
-//// Types
-////
+/// A TranspositionTable consists of a power of 2 number of clusters and each
+/// cluster consists of ClusterSize number of TTEntry. Each non-empty entry
+/// contains information of exactly one position. Size of a cluster shall not be
+/// bigger than a cache line size. In case it is less, it should be padded to
+/// guarantee always aligned accesses.
 
-/// The TTEntry class is the class of transposition table entries.
+class TranspositionTable {
 
-class TTEntry {
+  static const unsigned ClusterSize = 4; // A cluster is 64 Bytes
 
 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 & 0x7FFFF); }
-  Value value() const { return Value(value_); }
-  ValueType type() const { return ValueType((data >> 20) & 7); }
-  int generation() const { return (data >> 23); }
+ ~TranspositionTable() { free(mem); }
+  void new_search() { generation++; }
+
+  const TTEntry* probe(const Key key) const;
+  TTEntry* first_entry(const Key key) const;
+  void refresh(const TTEntry* tte) const;
+  void set_size(size_t mbSize);
+  void clear();
+  void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV, Value kingD);
 
 private:
-  Key key_;
-  uint32_t data;
-  int16_t value_;
-  int16_t depth_;
+  uint32_t hashMask;
+  TTEntry* table;
+  void* mem;
+  uint8_t generation; // Size must be not bigger than TTEntry::generation8
 };
 
-/// 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.
+extern TranspositionTable TT;
 
-class TranspositionTable {
 
-public:
-  TranspositionTable(unsigned mbSize);
-  ~TranspositionTable();
-  void set_size(unsigned mbSize);
-  void clear();
-  void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
-  TTEntry* retrieve(const Position &pos) const;
-  void new_search();
-  void insert_pv(const Position &pos, Move pv[]);
-  int full();
+/// 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.
 
-private:
-  inline TTEntry* first_entry(const Position &pos) const;
+inline TTEntry* TranspositionTable::first_entry(const Key key) const {
 
-  unsigned size;
-  int writes;
-  TTEntry* entries;
-  uint8_t generation;
-};
+  return table + ((uint32_t)key & hashMask);
+}
 
 
-////
-//// 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)
+#endif // #ifndef TT_H_INCLUDED