X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=4afd965b0fabb70abc106fa975a3e5c1ab469a8b;hp=8a66812a79c1eda84909dc20d09ead945a1c89de;hb=d9caede3249698440b7579e31d92aaa9984a128b;hpb=9edc7d6958fd616daecb0ab9ae2aa92042b3d34a

diff --git a/src/tt.cpp b/src/tt.cpp
index 8a66812a..4afd965b 100644
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, 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
@@ -25,42 +25,31 @@
 
 TranspositionTable TT; // Our global transposition table
 
-TranspositionTable::TranspositionTable() {
-
-  size = generation = 0;
-  entries = NULL;
-}
-
-TranspositionTable::~TranspositionTable() {
-
-  delete [] entries;
-}
 
+/// TranspositionTable::resize() sets the size of the transposition table,
+/// measured in megabytes. Transposition table consists of a power of 2 number
+/// of clusters and each cluster consists of TTClusterSize number of TTEntry.
 
-/// 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.
+void TranspositionTable::resize(size_t mbSize) {
 
-void TranspositionTable::set_size(size_t mbSize) {
+  size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(TTCluster));
 
-  size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTCluster));
-
-  if (newSize == size)
+  if (newClusterCount == clusterCount)
       return;
 
-  size = newSize;
-  delete [] entries;
-  entries = new (std::nothrow) TTCluster[size];
+  clusterCount = newClusterCount;
+
+  free(mem);
+  mem = calloc(clusterCount * sizeof(TTCluster) + CACHE_LINE_SIZE - 1, 1);
 
-  if (!entries)
+  if (!mem)
   {
       std::cerr << "Failed to allocate " << mbSize
                 << "MB for transposition table." << std::endl;
       exit(EXIT_FAILURE);
   }
 
-  clear(); // Operator new is not guaranteed to initialize memory to zero
+  table = (TTCluster*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));
 }
 
 
@@ -70,75 +59,62 @@ void TranspositionTable::set_size(size_t mbSize) {
 
 void TranspositionTable::clear() {
 
-  memset(entries, 0, size * sizeof(TTCluster));
+  std::memset(table, 0, clusterCount * sizeof(TTCluster));
 }
 
 
-/// TranspositionTable::store() writes a new entry containing position key and
-/// valuable information of current position. The lowest order bits of position
-/// key are used to decide on which cluster the position will be placed.
-/// When a new entry is written and there are no empty entries available in cluster,
-/// it replaces the least valuable of entries. A TTEntry t1 is considered to be
-/// more valuable than a TTEntry t2 if t1 is from the current search and t2 is from
-/// a previous search, or if the depth of t1 is bigger than the depth of t2.
-
-void TranspositionTable::store(const Key posKey, Value v, Bound b, Depth d, Move m) {
-
-  int c1, c2, c3;
-  TTEntry *tte, *replace;
-  uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key inside the cluster
+/// TranspositionTable::probe() looks up the current position in the
+/// transposition table. Returns a pointer to the TTEntry or NULL if
+/// position is not found.
 
-  tte = replace = first_entry(posKey);
+const TTEntry* TranspositionTable::probe(const Key key) const {
 
-  for (int i = 0; i < ClusterSize; i++, tte++)
-  {
-      if (!tte->key())
-          tte->save(posKey32, v, b, d, m, generation);
+  TTEntry* tte = first_entry(key);
+  uint16_t key16 = key >> 48;
 
-      if (tte->key() == posKey32)
+  for (unsigned i = 0; i < TTClusterSize; ++i, ++tte)
+      if (tte->key16 == key16)
       {
-          // Preserve any existing ttMove
-          if (m == MOVE_NONE)
-              m = tte->move();
-
-          tte->update(v, b, d, m, generation);
-          return;
+          tte->genBound8 = uint8_t(generation | tte->bound()); // Refresh
+          return tte;
       }
 
-      // Implement replace strategy
-      c1 = (replace->generation() == generation ?  2 : 0);
-      c2 = (tte->generation() == generation || tte->type() == BOUND_EXACT ? -2 : 0);
-      c3 = (tte->depth() < replace->depth() ?  1 : 0);
-
-      if (c1 + c2 + c3 > 0)
-          replace = tte;
-  }
-  replace->save(posKey32, v, b, d, m, generation);
+  return NULL;
 }
 
 
-/// TranspositionTable::probe() looks up the current position in the
-/// transposition table. Returns a pointer to the TTEntry or NULL if
-/// position is not found.
+/// TranspositionTable::store() writes a new entry containing position key and
+/// valuable information of current position. The lowest order bits of position
+/// key are used to decide in which cluster the position will be placed.
+/// When a new entry is written and there are no empty entries available in the
+/// cluster, it replaces the least valuable of the entries. A TTEntry t1 is considered
+/// to be more valuable than a TTEntry t2 if t1 is from the current search and t2
+/// is from a previous search, or if the depth of t1 is bigger than the depth of t2.
 
-TTEntry* TranspositionTable::probe(const Key posKey) const {
+void TranspositionTable::store(const Key key, Value v, Bound b, Depth d, Move m, Value statV) {
 
-  uint32_t posKey32 = posKey >> 32;
-  TTEntry* tte = first_entry(posKey);
+  TTEntry *tte, *replace;
+  uint16_t key16 = key >> 48; // Use the high 16 bits as key inside the cluster
 
-  for (int i = 0; i < ClusterSize; i++, tte++)
-      if (tte->key() == posKey32)
-          return tte;
+  tte = replace = first_entry(key);
 
-  return NULL;
-}
+  for (unsigned i = 0; i < TTClusterSize; ++i, ++tte)
+  {
+      if (!tte->key16 || tte->key16 == key16) // Empty or overwrite old
+      {
+          if (!m)
+              m = tte->move(); // Preserve any existing ttMove
 
+          replace = tte;
+          break;
+      }
 
-/// 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.
+      // Implement replace strategy
+      if (  ((    tte->genBound8 & 0xFC) == generation || tte->bound() == BOUND_EXACT)
+          - ((replace->genBound8 & 0xFC) == generation)
+          - (tte->depth8 < replace->depth8) < 0)
+          replace = tte;
+  }
 
-void TranspositionTable::new_search() {
-  generation++;
+  replace->save(key16, v, b, d, m, generation, statV);
 }