Change TT interface to ask directly for a position key

[stockfish] / src / tt.h

diff --git a/src/tt.h b/src/tt.h
index c1dd8508c2fadde864d8eb3a4932ca1b0812d3b1..e8dc021bafc1d537524ebdfa2b55754d98388f6b 100644 (file)
--- a/src/tt.h
+++ b/src/tt.h
@@ -1,13 +1,14 @@
 /*
-  Glaurung, a UCI chess playing engine.
-  Copyright (C) 2004-2008 Tord Romstad
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+  Copyright (C) 2008 Marco Costalba
 
-  Glaurung is free software: you can redistribute it and/or modify
+  Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
-  Glaurung is distributed in the hope that it will be useful,
+  Stockfish is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
@@ -33,18 +34,35 @@
 //// Types
 ////
 
-/// The TTEntry class is the class of transposition table entries.
+/// The TTEntry class is the class of transposition table entries
+///
+/// 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
 
 class TTEntry {
 
 public:
-  TTEntry();
-  TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation);
+  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 & 0x7FFFF); }
+  Move move() const { return Move(data & 0x1FFFF); }
   Value value() const { return Value(value_); }
-  ValueType type() const { return ValueType((data >> 20) & 3); }
+  ValueType type() const { return ValueType((data >> 20) & 7); }
   int generation() const { return (data >> 23); }
 
 private:
@@ -61,32 +79,22 @@ private:
 class TranspositionTable {
 
 public:
-  TranspositionTable(unsigned mbSize);
+  TranspositionTable();
   ~TranspositionTable();
   void set_size(unsigned mbSize);
   void clear();
-  void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
-  const TTEntry* retrieve(const Position &pos) const;
+  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();
+  void insert_pv(const Position& pos, Move pv[]);
+  int full() const;
 
 private:
-  inline TTEntry* first_entry(const Position &pos) const;
+  inline TTEntry* first_entry(const Key posKey) const;
 
-  unsigned size;
-  int writes;
+  unsigned size, writes;
   TTEntry* entries;
   uint8_t generation;
 };
 
-
-////
-//// Constants and variables
-////
-
-// Default transposition table size, in megabytes:
-const int TTDefaultSize = 32;
-
-
 #endif // !defined(TT_H_INCLUDED)