Retire TTCluster and simplify TT

Also some renaming while there.

No functional change.

diff --git a/src/search.cpp b/src/search.cpp
index cabd1cca38c02d31693bbbc5f8be3c4e00e8fa18..091c00fe2e06a9e8b6c194bdc460440d9f3d957c 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -594,8 +594,8 @@ namespace {
     else if (tte)
     {
         // Never assume anything on values stored in TT
-        if (  (ss->staticEval = eval = tte->static_value()) == VALUE_NONE
-            ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE)
+        if (  (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE
+            ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE)
             eval = ss->staticEval = evaluate(pos, ss->evalMargin);
 
         // Can ttValue be used as a better position evaluation?
@@ -1164,8 +1164,8 @@ split_point_start: // At split points actual search starts from here
         if (tte)
         {
             // Never assume anything on values stored in TT
-            if (  (ss->staticEval = bestValue = tte->static_value()) == VALUE_NONE
-                ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE)
+            if (  (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE
+                ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE)
                 ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
         }
         else

diff --git a/src/tt.cpp b/src/tt.cpp
index a7042f9ef2b9c56a83cb987f30345eda5e0604d6..2445f79420692c870922e7c88e77906af3ff0144 100644 (file)
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -25,33 +25,21 @@
 
 TranspositionTable TT; // Our global transposition table
 
-TranspositionTable::TranspositionTable() {
-
-  size = generation = 0;
-  entries = NULL;
-}
-
-TranspositionTable::~TranspositionTable() {
-
-  delete [] entries;
-}
-
 
 /// TranspositionTable::set_size() sets the size of the transposition table,
-/// measured in megabytes. Transposition table consists of a power of 2 number of
-/// TTCluster and each cluster consists of ClusterSize number of TTEntries. Each
-/// non-empty entry contains information of exactly one position.
+/// measured in megabytes. Transposition table consists of a power of 2 number
+/// of clusters and each cluster consists of ClusterSize number of TTEntry.
 
 void TranspositionTable::set_size(size_t mbSize) {
 
-  size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTCluster));
+  size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize]));
 
   if (newSize == size)
       return;
 
   size = newSize;
   delete [] entries;
-  entries = new (std::nothrow) TTCluster[size];
+  entries = new (std::nothrow) TTEntry[size * ClusterSize];
 
   if (!entries)
   {
@@ -70,7 +58,7 @@ void TranspositionTable::set_size(size_t mbSize) {
 
 void TranspositionTable::clear() {
 
-  memset(entries, 0, size * sizeof(TTCluster));
+  memset(entries, 0, size * sizeof(TTEntry[ClusterSize]));
 }
 
 
@@ -90,7 +78,7 @@ void TranspositionTable::store(const Key key, Value v, Bound t, Depth d, Move m,
 
   tte = replace = first_entry(key);
 
-  for (int i = 0; i < ClusterSize; i++, tte++)
+  for (unsigned i = 0; i < ClusterSize; i++, tte++)
   {
       if (!tte->key() || tte->key() == key32) // Empty or overwrite old
       {
@@ -123,19 +111,9 @@ TTEntry* TranspositionTable::probe(const Key key) const {
   TTEntry* tte = first_entry(key);
   uint32_t key32 = key >> 32;
 
-  for (int i = 0; i < ClusterSize; i++, tte++)
+  for (unsigned i = 0; i < ClusterSize; i++, tte++)
       if (tte->key() == key32)
           return tte;
 
   return NULL;
 }
-
-
-/// TranspositionTable::new_search() is called at the beginning of every new
-/// search. It increments the "generation" variable, which is used to
-/// distinguish transposition table entries from previous searches from
-/// entries from the current search.
-
-void TranspositionTable::new_search() {
-  generation++;
-}

diff --git a/src/tt.h b/src/tt.h
index 705bac9161edb5c882b9c8224042b42a041ad0b1..3484f0eb46163895d9dca72b47a70bd6e6fa5453 100644 (file)
--- a/src/tt.h
+++ b/src/tt.h
@@ -44,7 +44,7 @@
 class TTEntry {
 
 public:
-  void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value statV, Value statM) {
+  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;
@@ -52,63 +52,52 @@ public:
     generation8  = (uint8_t)g;
     value16      = (int16_t)v;
     depth16      = (int16_t)d;
-    staticValue  = (int16_t)statV;
-    staticMargin = (int16_t)statM;
+    evalValue    = (int16_t)ev;
+    evalMargin   = (int16_t)em;
   }
   void set_generation(int g) { generation8 = (uint8_t)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 type() const                { return (Bound)bound; }
-  int generation() const            { return (int)generation8; }
-  Value static_value() const        { return (Value)staticValue; }
-  Value static_value_margin() const { return (Value)staticMargin; }
+  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 type() const        { return (Bound)bound; }
+  int generation() const    { return (int)generation8; }
+  Value eval_value() const  { return (Value)evalValue; }
+  Value eval_margin() const { return (Value)evalMargin; }
 
 private:
   uint32_t key32;
   uint16_t move16;
   uint8_t bound, generation8;
-  int16_t value16, depth16, staticValue, staticMargin;
+  int16_t value16, depth16, evalValue, evalMargin;
 };
 
 
-/// This is the number of TTEntry slots for each cluster
-const int ClusterSize = 4;
-
-
-/// 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];
-};
-
-
-/// The transposition table class. This is basically just a huge array containing
-/// TTCluster objects, and a few methods for writing and reading entries.
+/// 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.
 
 class TranspositionTable {
 
-  TranspositionTable(const TranspositionTable&);
-  TranspositionTable& operator=(const TranspositionTable&);
+  static const unsigned ClusterSize = 4; // A cluster is 64 Bytes
 
 public:
-  TranspositionTable();
- ~TranspositionTable();
+ ~TranspositionTable() { delete [] entries; }
+  void new_search() { generation++; }
+
+  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);
-  TTEntry* probe(const Key key) const;
-  void new_search();
-  TTEntry* first_entry(const Key posKey) const;
-  void refresh(const TTEntry* tte) const;
 
 private:
   size_t size;
-  TTCluster* entries;
+  TTEntry* entries;
   uint8_t generation; // Size must be not bigger then TTEntry::generation8
 };
 
@@ -119,9 +108,9 @@ extern TranspositionTable TT;
 /// 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 {
+inline TTEntry* TranspositionTable::first_entry(const Key key) const {
 
-  return entries[((uint32_t)posKey) & (size - 1)].data;
+  return entries + ((uint32_t)key & (size - 1)) * ClusterSize;
 }