X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=24e94c8008bd691c4045719f065359dd1ff3ee5a;hp=7295225718214bb03bad17563304f32014dce939;hb=40c863d41af5058a02f1de3423a000d801dcb08a;hpb=67d91dfd505ce7e2c641c12e5d14b50896874ec7 diff --git a/src/tt.cpp b/src/tt.cpp index 72952257..24e94c80 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 +25,32 @@ 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(uint64_t mbSize) { -void TranspositionTable::set_size(size_t mbSize) { + assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32); - size_t newSize = 1ULL << last_1((mbSize << 20) / sizeof(TTCluster)); + 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)); } @@ -70,72 +60,62 @@ 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; } /// 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 posKey, Value v, Bound t, Depth d, Move m, Value statV, Value kingD) { +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 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, statV, kingD); - 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, statV, kingD); -} - - -/// 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); }