X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=92aaee001824276e49f1090c72ec451070900dd0;hp=653d081f8f0eb01859408043467a4e0486241f2f;hb=4b10578acbe099482ed40200478df4d775c01af5;hpb=656aad8b0c10f43eae7744edc1b7171720ac7426

diff --git a/src/tt.cpp b/src/tt.cpp
index 653d081f..92aaee00 100644
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -30,10 +30,10 @@
 
 TranspositionTable TT; // Our global transposition table
 
-/// TTEntry::save saves a TTEntry
-void TTEntry::save(Key k, Value v, 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, Bound b, Depth d, Move m, Value ev) {
 
   // 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 | b);
-      depth8    = (int8_t)(d / ONE_PLY);
+      genBound8 = (uint8_t)(TT.generation8 | uint8_t(pv) << 2 | b);
+      depth8    = (uint8_t)(d - DEPTH_OFFSET);
   }
 }
 
@@ -61,11 +63,12 @@ void TranspositionTable::resize(size_t mbSize) {
 
   Threads.main()->wait_for_search_finished();
 
-  clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
+  aligned_ttmem_free(mem);
 
-  free(mem);
-  mem = malloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1);
+  superClusterCount = mbSize * 1024 * 1024 / (sizeof(Cluster) * ClustersPerSuperCluster);
 
+  table = static_cast<Cluster*>(
+      aligned_ttmem_alloc(superClusterCount * ClustersPerSuperCluster * sizeof(Cluster), mem));
   if (!mem)
   {
       std::cerr << "Failed to allocate " << mbSize
@@ -73,7 +76,6 @@ void TranspositionTable::resize(size_t mbSize) {
       exit(EXIT_FAILURE);
   }
 
-  table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));
   clear();
 }
 
@@ -89,13 +91,15 @@ void TranspositionTable::clear() {
   {
       threads.emplace_back([this, idx]() {
 
+          const size_t clusterCount = superClusterCount * ClustersPerSuperCluster;
+
           // Thread binding gives faster search on systems with a first-touch policy
           if (Options["Threads"] > 8)
               WinProcGroup::bindThisThread(idx);
 
           // Each thread will zero its part of the hash table
-          const size_t stride = clusterCount / Options["Threads"],
-                       start  = stride * idx,
+          const size_t stride = size_t(clusterCount / Options["Threads"]),
+                       start  = size_t(stride * idx),
                        len    = idx != Options["Threads"] - 1 ?
                                 stride : clusterCount - start;
 
@@ -103,7 +107,7 @@ void TranspositionTable::clear() {
       });
   }
 
-  for (std::thread& th: threads)
+  for (std::thread& th : threads)
       th.join();
 }
 
@@ -122,7 +126,7 @@ 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].bound()); // Refresh
+          tte[i].genBound8 = uint8_t(generation8 | (tte[i].genBound8 & 0x7)); // Refresh
 
           return found = (bool)tte[i].key16, &tte[i];
       }
@@ -131,11 +135,11 @@ 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 259 (256 is the modulus plus 3 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 - ((259 + generation8 - replace->genBound8) & 0xFC) * 2
-          >   tte[i].depth8 - ((259 + generation8 -   tte[i].genBound8) & 0xFC) * 2)
+      if (  replace->depth8 - ((263 + generation8 - replace->genBound8) & 0xF8)
+          >   tte[i].depth8 - ((263 + generation8 -   tte[i].genBound8) & 0xF8))
           replace = &tte[i];
 
   return found = false, replace;
@@ -148,9 +152,9 @@ TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
 int TranspositionTable::hashfull() const {
 
   int cnt = 0;
-  for (int i = 0; i < 1000 / ClusterSize; ++i)
+  for (int i = 0; i < 1000; ++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));
+  return cnt / ClusterSize;
 }