Introduce king infiltration bonus

[stockfish] / src / tt.cpp

diff --git a/src/tt.cpp b/src/tt.cpp
index d05de9163164faa62f307c3ae16565094c62f152..d3cd094eed966541e84f4ab5b468fef4b626d17f 100644 (file)
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -30,10 +30,10 @@
 
 TranspositionTable TT; // Our global transposition table
 
-/// TTEntry::save saves a TTEntry
-void TTEntry::save(Key k, Value v, bool PvNode, Bound b, Depth d, Move m, Value ev) {
+/// TTEntry::save populates the TTEntry with a new node's data, possibly
+/// overwriting an old position. Update is not atomic and can be racy.
 
-  assert(d / ONE_PLY * ONE_PLY == d);
+void TTEntry::save(Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev) {
 
   // Preserve any existing move for the same position
   if (m || (k >> 48) != key16)
@@ -41,14 +41,16 @@ void TTEntry::save(Key k, Value v, bool PvNode, Bound b, Depth d, Move m, Value
 
   // Overwrite less valuable entries
   if (  (k >> 48) != key16
-      || d / ONE_PLY > depth8 - 4
+      || d - DEPTH_OFFSET > depth8 - 4
       || b == BOUND_EXACT)
   {
+      assert(d >= DEPTH_OFFSET);
+
       key16     = (uint16_t)(k >> 48);
       value16   = (int16_t)v;
       eval16    = (int16_t)ev;
-      genBound8 = (uint8_t)(TT.generation8 | PvNode << 2 | b);
-      depth8    = (int8_t)(d / ONE_PLY);
+      genBound8 = (uint8_t)(TT.generation8 | uint8_t(pv) << 2 | b);
+      depth8    = (uint8_t)(d - DEPTH_OFFSET);
   }
 }
 
@@ -122,7 +124,7 @@ TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
   for (int i = 0; i < ClusterSize; ++i)
       if (!tte[i].key16 || tte[i].key16 == key16)
       {
-          tte[i].genBound8 = uint8_t(generation8 | tte[i].pv_hit() << 2 | tte[i].bound()); // Refresh
+          tte[i].genBound8 = uint8_t(generation8 | (tte[i].genBound8 & 0x7)); // Refresh
 
           return found = (bool)tte[i].key16, &tte[i];
       }
@@ -131,8 +133,8 @@ TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
   TTEntry* replace = tte;
   for (int i = 1; i < ClusterSize; ++i)
       // Due to our packed storage format for generation and its cyclic
-      // nature we add 263 (263 is the modulus plus 7 to keep the lowest
-      // two bound bits from affecting the result) to calculate the entry
+      // nature we add 263 (256 is the modulus plus 7 to keep the unrelated
+      // lowest three bits from affecting the result) to calculate the entry
       // age correctly even after generation8 overflows into the next cycle.
       if (  replace->depth8 - ((263 + generation8 - replace->genBound8) & 0xF8)
           >   tte[i].depth8 - ((263 + generation8 -   tte[i].genBound8) & 0xF8))
@@ -150,7 +152,7 @@ int TranspositionTable::hashfull() const {
   int cnt = 0;
   for (int i = 0; i < 1000 / ClusterSize; ++i)
       for (int j = 0; j < ClusterSize; ++j)
-          cnt += (table[i].entry[j].genBound8 & 0xFC) == generation8;
+          cnt += (table[i].entry[j].genBound8 & 0xF8) == generation8;
 
   return cnt * 1000 / (ClusterSize * (1000 / ClusterSize));
 }