Retire PawnsFileSpan

[stockfish] / src / tt.cpp

diff --git a/src/tt.cpp b/src/tt.cpp
index 26436806c80fff71d0addb59e255d90fb9e72996..4afd965b0fabb70abc106fa975a3e5c1ab469a8b 100644 (file)
--- 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) 2008-2013 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
@@ -26,22 +26,21 @@
 TranspositionTable TT; // Our global transposition table
 
 
-/// TranspositionTable::set_size() sets the size of the transposition table,
+/// 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 ClusterSize number of TTEntry.
+/// of clusters and each cluster consists of TTClusterSize number of TTEntry.
 
-void TranspositionTable::set_size(size_t mbSize) {
+void TranspositionTable::resize(size_t mbSize) {
 
-  assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32);
+  size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(TTCluster));
 
-  uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize]));
-
-  if (hashMask == size - ClusterSize)
+  if (newClusterCount == clusterCount)
       return;
 
-  hashMask = size - ClusterSize;
+  clusterCount = newClusterCount;
+
   free(mem);
-  mem = calloc(size * sizeof(TTEntry) + CACHE_LINE_SIZE - 1, 1);
+  mem = calloc(clusterCount * sizeof(TTCluster) + CACHE_LINE_SIZE - 1, 1);
 
   if (!mem)
   {
@@ -50,7 +49,7 @@ void TranspositionTable::set_size(size_t mbSize) {
       exit(EXIT_FAILURE);
   }
 
-  table = (TTEntry*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));
+  table = (TTCluster*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));
 }
 
 
@@ -60,7 +59,7 @@ void TranspositionTable::set_size(size_t mbSize) {
 
 void TranspositionTable::clear() {
 
-  std::memset(table, 0, (hashMask + ClusterSize) * sizeof(TTEntry));
+  std::memset(table, 0, clusterCount * sizeof(TTCluster));
 }
 
 
@@ -70,12 +69,15 @@ void TranspositionTable::clear() {
 
 const TTEntry* TranspositionTable::probe(const Key key) const {
 
-  const TTEntry* tte = first_entry(key);
-  uint32_t key32 = key >> 32;
+  TTEntry* tte = first_entry(key);
+  uint16_t key16 = key >> 48;
 
-  for (unsigned i = 0; i < ClusterSize; ++i, ++tte)
-      if (tte->key() == key32)
+  for (unsigned i = 0; i < TTClusterSize; ++i, ++tte)
+      if (tte->key16 == key16)
+      {
+          tte->genBound8 = uint8_t(generation | tte->bound()); // Refresh
           return tte;
+      }
 
   return NULL;
 }
@@ -83,23 +85,22 @@ const TTEntry* TranspositionTable::probe(const Key key) const {
 
 /// 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.
+/// 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.
 
 void TranspositionTable::store(const Key key, Value v, Bound b, Depth d, Move m, Value statV) {
 
-  int c1, c2, c3;
   TTEntry *tte, *replace;
-  uint32_t key32 = key >> 32; // Use the high 32 bits as key inside the cluster
+  uint16_t key16 = key >> 48; // Use the high 16 bits as key inside the cluster
 
   tte = replace = first_entry(key);
 
-  for (unsigned i = 0; i < ClusterSize; ++i, ++tte)
+  for (unsigned i = 0; i < TTClusterSize; ++i, ++tte)
   {
-      if (!tte->key() || tte->key() == key32) // Empty or overwrite old
+      if (!tte->key16 || tte->key16 == key16) // Empty or overwrite old
       {
           if (!m)
               m = tte->move(); // Preserve any existing ttMove
@@ -109,13 +110,11 @@ void TranspositionTable::store(const Key key, Value v, Bound b, Depth d, Move m,
       }
 
       // Implement replace strategy
-      c1 = (replace->generation() == generation ?  2 : 0);
-      c2 = (tte->generation() == generation || tte->bound() == BOUND_EXACT ? -2 : 0);
-      c3 = (tte->depth() < replace->depth() ?  1 : 0);
-
-      if (c1 + c2 + c3 > 0)
+      if (  ((    tte->genBound8 & 0xFC) == generation || tte->bound() == BOUND_EXACT)
+          - ((replace->genBound8 & 0xFC) == generation)
+          - (tte->depth8 < replace->depth8) < 0)
           replace = tte;
   }
 
-  replace->save(key32, v, b, d, m, generation, statV);
+  replace->save(key16, v, b, d, m, generation, statV);
 }