X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=55aad112af3c252d6006265132e8cb657d70d5f6;hp=8ef2a63500acf02827028a6e485a2286881dfd6f;hb=af3dd21e9053feaf66ad884fae0a014d85c700f2;hpb=4251eac8601af47d1ee2d6f613f00a4bf00fedbb

diff --git a/src/tt.cpp b/src/tt.cpp
index 8ef2a635..55aad112 100644
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -30,10 +30,8 @@
 #include "movegen.h"
 #include "tt.h"
 
-
-/// This is the number of TTEntry slots for each position
-static const int ClusterSize = 5;
-
+// The main transposition table
+TranspositionTable TT;
 
 ////
 //// Functions
@@ -63,14 +61,14 @@ void TranspositionTable::set_size(unsigned mbSize) {
 
   // We store a cluster of ClusterSize number of TTEntry for each position
   // and newSize is the maximum number of storable positions.
-  while ((2 * newSize) * ClusterSize * (sizeof(TTEntry)) <= (mbSize << 20))
+  while ((2 * newSize) * sizeof(TTCluster) <= (mbSize << 20))
       newSize *= 2;
 
   if (newSize != size)
   {
       size = newSize;
       delete [] entries;
-      entries = new TTEntry[size * ClusterSize];
+      entries = new TTCluster[size];
       if (!entries)
       {
           std::cerr << "Failed to allocate " << mbSize
@@ -89,7 +87,7 @@ void TranspositionTable::set_size(unsigned mbSize) {
 
 void TranspositionTable::clear() {
 
-  memset(entries, 0, size * ClusterSize * sizeof(TTEntry));
+  memset(entries, 0, size * sizeof(TTCluster));
 }
 
 
@@ -99,7 +97,7 @@ void TranspositionTable::clear() {
 
 inline TTEntry* TranspositionTable::first_entry(const Key posKey) const {
 
-  return entries + ((uint32_t(posKey) & (size - 1)) * ClusterSize);
+  return entries[uint32_t(posKey) & (size - 1)].data;
 }
 
 
@@ -123,8 +121,8 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d,
   {
       if (!tte->key() || tte->key() == posKey32) // empty or overwrite old
       {
-          // Do not overwrite when new type is VALUE_TYPE_EVAL
-          if (tte->key() && t == VALUE_TYPE_EVAL)
+          // Do not overwrite when new type is VALUE_TYPE_EV_LO
+          if (tte->key() && t == VALUE_TYPE_EV_LO)
               return;
 
           if (m == MOVE_NONE)
@@ -170,11 +168,19 @@ TTEntry* TranspositionTable::retrieve(const Key posKey) const {
 /// blocking function and do not stalls the CPU waiting for data
 /// to be loaded from RAM, that can be very slow. When we will
 /// subsequently call retrieve() the TT data will be already
-/// quickly accessible in L1/l2 CPU cache.
+/// quickly accessible in L1/L2 CPU cache.
 
 void TranspositionTable::prefetch(const Key posKey) const {
 
-  _mm_prefetch((char*)first_entry(posKey), _MM_HINT_T0);
+#if defined(__INTEL_COMPILER) || defined(__ICL)
+   // This hack prevents prefetches to be optimized away by the
+   // Intel compiler. Both MSVC and gcc seems not affected.
+   __asm__ ("");
+#endif
+
+   char const* addr = (char*)first_entry(posKey);
+  _mm_prefetch(addr, _MM_HINT_T2);
+  _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead
 }
 
 
@@ -214,27 +220,26 @@ void TranspositionTable::insert_pv(const Position& pos, Move pv[]) {
 /// will often get single-move PVs when the search stops while failing high,
 /// and a single-move PV means that we don't have a ponder move.
 
-void TranspositionTable::extract_pv(const Position& pos, Move pv[]) {
-
-  int ply;
-  Position p(pos);
-  StateInfo st[100];
-
-  for (ply = 0; pv[ply] != MOVE_NONE; ply++)
-      p.do_move(pv[ply], st[ply]);
+void TranspositionTable::extract_pv(const Position& pos, Move pv[], const int PLY_MAX) {
 
-  bool stop;
   const TTEntry* tte;
-  for (stop = false, tte = retrieve(p.get_key());
-       tte && tte->move() != MOVE_NONE && !stop;
-       tte = retrieve(p.get_key()), ply++)
+  StateInfo st;
+  Position p(pos);
+  int ply = 0;
+
+  // Update position to the end of current PV
+  while (pv[ply] != MOVE_NONE)
+      p.do_move(pv[ply++], st);
+
+  // Try to add moves from TT while possible
+  while (   (tte = retrieve(p.get_key())) != NULL
+         && tte->move() != MOVE_NONE
+         && move_is_legal(p, tte->move())
+         && (!p.is_draw() || ply < 2)
+         && ply < PLY_MAX)
   {
-      if (!move_is_legal(p, tte->move()))
-          break;
       pv[ply] = tte->move();
-      p.do_move(pv[ply], st[ply]);
-      for (int j = 0; j < ply; j++)
-          if (st[j].key == p.get_key()) stop = true;
+      p.do_move(pv[ply++], st);
   }
   pv[ply] = MOVE_NONE;
 }