X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=248cbad96d930baebe75d7bae3536145a69ccd1a;hp=271b98b74009eaf8f7e5e6601c5225c33a5be7f5;hb=ccd823a4ffd2ed3e60cb03ab49a841742bae1994;hpb=481eda4ca0121cfa16f5a29f364ca30ee2852409 diff --git a/src/tt.cpp b/src/tt.cpp index 271b98b7..248cbad9 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) 2008-2013 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 +26,23 @@ 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(uint64_t mbSize) { - assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32); + assert(msb((mbSize * 1024 * 1024) / sizeof(TTCluster)) < 32); - uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize])); + uint32_t newClusterCount = 1 << msb((mbSize * 1024 * 1024) / sizeof(TTCluster)); - if (hashMask == size - ClusterSize) + if (newClusterCount == clusterCount) return; - hashMask = size - ClusterSize; + clusterCount = newClusterCount; + free(mem); - mem = malloc(size * sizeof(TTEntry) + CACHE_LINE_SIZE - 1); + mem = calloc(clusterCount * sizeof(TTCluster) + CACHE_LINE_SIZE - 1, 1); if (!mem) { @@ -50,9 +51,7 @@ void TranspositionTable::set_size(size_t mbSize) { exit(EXIT_FAILURE); } - // Align table start address to a cache line - for (char* c = (char*)mem; unsigned(table = (TTEntry*)(c)) % CACHE_LINE_SIZE; c++) {} - clear(); // Operator new is not guaranteed to initialize memory to zero + table = (TTCluster*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1)); } @@ -62,62 +61,62 @@ void TranspositionTable::set_size(size_t mbSize) { void TranspositionTable::clear() { - memset(table, 0, (hashMask + ClusterSize) * sizeof(TTEntry)); + std::memset(table, 0, clusterCount * sizeof(TTCluster)); +} + + +/// 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 { + + TTEntry* tte = first_entry(key); + uint16_t key16 = key >> 48; + + for (unsigned i = 0; i < TTClusterSize; ++i, ++tte) + if (tte->key16 == key16) + { + tte->genBound8 = generation | tte->bound(); // Refresh + 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 key, 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 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 { - // Preserve any existing ttMove - if (m == MOVE_NONE) - m = tte->move(); + if (!m) + m = tte->move(); // Preserve any existing ttMove - tte->save(key32, 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); - 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, 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 key) 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; + replace->save(key16, v, b, d, m, generation, statV); }