X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=9774a2332fa8fd481983ee90b729195ec7112aeb;hp=40dca0d3b2524b221d14f0d2a7fccf2049d3a64a;hb=45b0aea875860e9f0fe2d0435ee6163906639194;hpb=6fa83f51889248b16f539db4ce0fe5b23f2a85d6 diff --git a/src/tt.cpp b/src/tt.cpp index 40dca0d3..9774a233 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) 2008-2013 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 +25,32 @@ TranspositionTable TT; // Our global transposition table -TranspositionTable::TranspositionTable() { - - size = generation = 0; - entries = NULL; -} - -TranspositionTable::~TranspositionTable() { - - delete [] entries; -} - /// 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. +/// measured in megabytes. Transposition table consists of a power of 2 number +/// of clusters and each cluster consists of ClusterSize number of TTEntry. void TranspositionTable::set_size(size_t mbSize) { - size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTCluster)); + assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32); + + uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize])); - if (newSize == size) + if (hashMask == size - ClusterSize) return; - size = newSize; - delete [] entries; - entries = new (std::nothrow) TTCluster[size]; + hashMask = size - ClusterSize; + free(mem); + mem = calloc(size * sizeof(TTEntry) + 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 = (TTEntry*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1)); } @@ -70,7 +60,24 @@ void TranspositionTable::set_size(size_t mbSize) { void TranspositionTable::clear() { - memset(entries, 0, size * sizeof(TTCluster)); + std::memset(table, 0, (hashMask + ClusterSize) * sizeof(TTEntry)); +} + + +/// TranspositionTable::probe() looks up the current position in the +/// transposition table. Returns a pointer to the TTEntry or NULL if +/// position is not found. + +const TTEntry* TranspositionTable::probe(const Key key) const { + + const TTEntry* tte = first_entry(key); + uint32_t key32 = key >> 32; + + for (unsigned i = 0; i < ClusterSize; i++, tte++) + if (tte->key() == key32) + return tte; + + return NULL; } @@ -82,60 +89,33 @@ void TranspositionTable::clear() { /// 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 t, Depth d, Move m) { +void TranspositionTable::store(const Key key, Value v, Bound b, Depth d, Move m, Value statV, Value evalM) { int c1, c2, c3; TTEntry *tte, *replace; - uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key inside the cluster + uint32_t key32 = key >> 32; // Use the high 32 bits as key inside the cluster - tte = replace = first_entry(posKey); + tte = replace = first_entry(key); - for (int i = 0; i < ClusterSize; i++, tte++) + for (unsigned i = 0; i < ClusterSize; i++, tte++) { - if (!tte->key() || tte->key() == posKey32) // Empty or overwrite old + if (!tte->key() || tte->key() == key32) // Empty or overwrite old { - // Preserve any existing ttMove - if (m == MOVE_NONE) - m = tte->move(); + if (!m) + m = tte->move(); // Preserve any existing ttMove - tte->save(posKey32, v, t, d, m, generation); - return; + replace = tte; + break; } // Implement replace strategy c1 = (replace->generation() == generation ? 2 : 0); - c2 = (tte->generation() == generation || tte->type() == BOUND_EXACT ? -2 : 0); + c2 = (tte->generation() == generation || tte->bound() == BOUND_EXACT ? -2 : 0); c3 = (tte->depth() < replace->depth() ? 1 : 0); if (c1 + c2 + c3 > 0) replace = tte; } - replace->save(posKey32, v, t, d, m, generation); -} - - -/// TranspositionTable::probe() looks up the current position in the -/// transposition table. Returns a pointer to the TTEntry or NULL if -/// position is not found. - -TTEntry* TranspositionTable::probe(const Key posKey) const { - - uint32_t posKey32 = posKey >> 32; - TTEntry* tte = first_entry(posKey); - - for (int i = 0; i < ClusterSize; i++, tte++) - if (tte->key() == posKey32) - return tte; - - return NULL; -} - - -/// 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. -void TranspositionTable::new_search() { - generation++; + replace->save(key32, v, b, d, m, generation, statV, evalM); }