X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.h;h=534409f32800bfc34110d931cac3bd29e0827cfe;hp=fb414bf157aeba9fa98fbe70bbb728cd27445e1e;hb=15e21911110f9d459c4fef2bb17903d97345d0b9;hpb=630fda2e2cfd44ccf33c2c66ec30842fbca9a4f3

diff --git a/src/tt.h b/src/tt.h
index fb414bf1..534409f3 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) 2008-2009 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
@@ -17,90 +17,98 @@
   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 "depth.h"
-#include "position.h"
-#include "value.h"
+#include "misc.h"
+#include "types.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 {
+
+  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; }
+  Bound bound() const      { return (Bound)(genBound8 & 0x3); }
 
-////
-//// Types
-////
+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;
+    genBound8 = (uint8_t)(g | b);
+    depth8    = (int8_t)d;
+  }
+
+  uint16_t key16;
+  uint16_t move16;
+  int16_t  value16;
+  int16_t  evalValue;
+  uint8_t  genBound8;
+  int8_t   depth8;
+};
 
-/// The TTEntry class is the class of transposition table entries
+/// TTCluster is a 32 bytes cluster of TT entries consisting of:
 ///
-/// A TTEntry needs 128 bits to be stored
-///
-/// bit    0-63: key
-/// bit   64-95: data
-/// bit  96-111: value
-/// bit 112-127: depth
-///
-/// 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 23-31: generation
+/// 3 x TTEntry (3 x 10 bytes)
+/// padding     (2 bytes)
 
-class TTEntry {
+const unsigned TTClusterSize = 3;
 
-public:
-  TTEntry() {}
-  TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation)
-        : key_ (k), data((m & 0x1FFFF) | (t << 20) | (generation << 23)),
-          value_(int16_t(v)), depth_(int16_t(d)) {}
-
-  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_;
+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();
-  ~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(size_t mbSize);
   void clear();
-  void store(const Key posKey, Value v, ValueType type, Depth d, Move m);
-  TTEntry* retrieve(const Key posKey) const;
-  void new_search();
-  void insert_pv(const Position& pos, Move pv[]);
-  int full() const;
+  void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV);
 
 private:
-  inline TTEntry* first_entry(const Key posKey) const;
+  size_t clusterCount;
+  TTCluster* table;
+  void* mem;
+  uint8_t generation; // Size must be not bigger than TTEntry::genBound8
+};
 
-  // Be sure 'writes' is at least one cacheline 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];
+extern TranspositionTable TT;
 
-  unsigned size;
-  TTEntry* entries;
-  uint8_t generation;
-};
 
-#endif // !defined(TT_H_INCLUDED)
+/// 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.
+
+inline TTEntry* TranspositionTable::first_entry(const Key key) const {
+
+  return &table[(size_t)key & (clusterCount - 1)].entry[0];
+}
+
+#endif // #ifndef TT_H_INCLUDED