X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.h;h=e9c25ad2d7da732b7ad7c071878887bb197c9824;hp=03ce1f553df77f9d5e46cf5232602bd7b956b13d;hb=ccd823a4ffd2ed3e60cb03ab49a841742bae1994;hpb=d3600c39a745179ed6b094b305d0645e83a1ee86

diff --git a/src/tt.h b/src/tt.h
index 03ce1f55..e9c25ad2 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) 2008-2014 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 +17,99 @@
   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"
 
-#include "depth.h"
-#include "position.h"
-#include "value.h"
+/// The TTEntry is the 10 bytes transposition table entry, defined as below:
+///
+/// key        16 bit
+/// move       16 bit
+/// value      16 bit
+/// eval value 16 bit
+/// generation  6 bit
+/// bound type  2 bit
+/// depth       8 bit
 
+struct TTEntry {
 
-////
-//// Types
-////
+  Move  move()  const      { return (Move )move16; }
+  Value value() const      { return (Value)value16; }
+  Value eval_value() const { return (Value)evalValue; }
+  Depth depth() const      { return (Depth)(depth8) + DEPTH_NONE; }
+  Bound bound() const      { return (Bound)(genBound8 & 0x3); }
 
-/// The TTEntry class is the class of transposition table entries.
+private:
+  friend class TranspositionTable;
+
+  void save(uint16_t k, Value v, Bound b, Depth d, Move m, uint8_t g, Value ev) {
+
+    key16     = (uint16_t)k;
+    move16    = (uint16_t)m;
+    value16   = (int16_t)v;
+    evalValue = (int16_t)ev;
+    depth8    = (uint8_t)(d - DEPTH_NONE);
+    genBound8 = g | (uint8_t)b;
+  }
+
+  uint16_t key16;
+  uint16_t move16;
+  int16_t  value16;
+  int16_t  evalValue;
+  uint8_t  genBound8;
+  uint8_t  depth8;
+};
 
-class TTEntry {
+/// TTCluster is a 32 bytes cluster of TT entries consisting of:
+///
+/// 3 x TTEntry (3 x 10 bytes)
+/// padding     (2 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) & 3); }
-  int generation() const { return (data >> 23); }
+const unsigned TTClusterSize = 3;
 
-private:
-  Key key_;
-  uint32_t data;
-  int16_t value_;
-  int16_t depth_;
+struct TTCluster {
+
+  TTEntry entry[TTClusterSize];
+  char padding[2];
 };
 
-/// 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.
+/// A TranspositionTable consists of a power of 2 number of clusters and each
+/// cluster consists of TTClusterSize number of TTEntry. Each non-empty entry
+/// contains information of exactly one position. The size of a cluster should
+/// not be bigger than a cache line size. In case it is less, it should be padded
+/// to guarantee always aligned accesses.
 
 class TranspositionTable {
 
 public:
-  TranspositionTable(unsigned mbSize);
-  ~TranspositionTable();
-  void set_size(unsigned mbSize);
+ ~TranspositionTable() { free(mem); }
+  void new_search() { generation += 4; } // Lower 2 bits are used by Bound
+
+  const TTEntry* probe(const Key key) const;
+  TTEntry* first_entry(const Key key) const;
+  void resize(uint64_t mbSize);
   void clear();
-  void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
-  const TTEntry* retrieve(const Position &pos) const;
-  void new_search();
-  void insert_pv(const Position &pos, Move pv[]);
-  int full();
+  void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV);
 
 private:
-  inline TTEntry* first_entry(const Position &pos) const;
-
-  unsigned size;
-  int writes;
-  TTEntry* entries;
-  uint8_t generation;
+  uint32_t clusterCount;
+  TTCluster* table;
+  void* mem;
+  uint8_t generation; // Size must be not bigger than TTEntry::genBound8
 };
 
+extern TranspositionTable TT;
+
 
-////
-//// Constants and variables
-////
+/// 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 inside the table.
 
-// Default transposition table size, in megabytes:
-const int TTDefaultSize = 32;
+inline TTEntry* TranspositionTable::first_entry(const Key key) const {
 
+  return &table[(uint32_t)key & (clusterCount - 1)].entry[0];
+}
 
-#endif // !defined(TT_H_INCLUDED)
+#endif // #ifndef TT_H_INCLUDED