Prefer int to uint8_t when possible

[stockfish] / src / tt.h

diff --git a/src/tt.h b/src/tt.h
index 042ccdfedee3b42988c95cba68ca4db5bc061a12..ff1cb910f63035d1d9582fe652d9c91171dc521d 100644 (file)
--- a/src/tt.h
+++ b/src/tt.h
@@ -26,7 +26,7 @@
 ////
 
 #include "depth.h"
-#include "position.h"
+#include "move.h"
 #include "value.h"
 
 
@@ -36,18 +36,20 @@
 
 /// The TTEntry class is the class of transposition table entries
 ///
-/// A TTEntry needs 96 bits to be stored
+/// 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  0-16: move
-/// bit 17-19: not used
-/// bit 20-22: value type
+/// bit 17-20: not used
+/// bit 21-22: value type
 /// bit 23-31: generation
 
 class TTEntry {
@@ -56,21 +58,22 @@ public:
   void save(uint32_t k, Value v, ValueType t, Depth d, Move m, int g, Value statV, Value kd) {
 
       key32 = k;
-      data = (m & 0x1FFFF) | (t << 20) | (g << 23);
+      data = (m & 0x1FFFF) | (t << 21) | (g << 23);
       value16     = int16_t(v);
       depth16     = int16_t(d);
       staticValue = int16_t(statV);
-      kingDanger  = int16_t(kd);
+      staticValueMargin  = int16_t(kd);
   }
+  void set_generation(int g) { data = move() | (type() << 21) | (g << 23); }
 
   uint32_t key() const { return key32; }
   Depth depth() const { return Depth(depth16); }
   Move move() const { return Move(data & 0x1FFFF); }
   Value value() const { return Value(value16); }
-  ValueType type() const { return ValueType((data >> 20) & 7); }
+  ValueType type() const { return ValueType((data >> 21) & 3); }
   int generation() const { return data >> 23; }
   Value static_value() const { return Value(staticValue); }
-  Value king_danger() const { return Value(kingDanger); }
+  Value static_value_margin() const { return Value(staticValueMargin); }
 
 private:
   uint32_t key32;
@@ -78,17 +81,16 @@ private:
   int16_t value16;
   int16_t depth16;
   int16_t staticValue;
-  int16_t kingDanger;
+  int16_t staticValueMargin;
 };
 
 
-/// This is the number of TTEntry slots for each position
+/// This is the number of TTEntry slots for each cluster
 const int ClusterSize = 4;
 
-/// Each group of ClusterSize number of TTEntry form a TTCluster
-/// that is indexed by a single position key. TTCluster size must
-///  be not bigger then a cache line size, in case it is less then
-/// it should be padded to guarantee always aligned accesses.
+/// 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];
@@ -96,11 +98,14 @@ struct TTCluster {
 
 
 /// The transposition table class. This is basically just a huge array
-/// containing TTEntry objects, and a few methods for writing new entries
+/// containing TTCluster objects, and a few methods for writing new entries
 /// and reading new ones.
 
 class TranspositionTable {
 
+  TranspositionTable(const TranspositionTable&);
+  TranspositionTable& operator=(const TranspositionTable&);
+
 public:
   TranspositionTable();
   ~TranspositionTable();
@@ -108,26 +113,35 @@ public:
   void clear();
   void store(const Key posKey, Value v, ValueType type, Depth d, Move m, Value statV, Value kingD);
   TTEntry* retrieve(const Key posKey) const;
-  void prefetch(const Key posKey) const;
   void new_search();
-  void insert_pv(const Position& pos, Move pv[]);
-  void extract_pv(const Position& pos, Move pv[], const int PLY_MAX);
-  int full() const;
+  TTEntry* first_entry(const Key posKey) const;
+  void refresh(const TTEntry* tte) const;
 
 private:
-  inline TTEntry* first_entry(const Key posKey) const;
-
-  // Be sure 'writes' is at least one cache line 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];
-
   size_t size;
   TTCluster* entries;
-  uint8_t generation;
+  int generation;
 };
 
 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;
+}
+
+
+/// TranspositionTable::refresh updates the 'generation' value of the TTEntry
+/// to avoid aging. Normally called after a TT hit, before to return.
+
+inline void TranspositionTable::refresh(const TTEntry* tte) const {
+
+  const_cast<TTEntry*>(tte)->set_generation(generation);
+}
+
 #endif // !defined(TT_H_INCLUDED)