X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=2979c104aac3020c3798996597b182174b03ad4b;hp=117b60027a1678d034b88fe82ed93d7d57194266;hb=14cf27e6f65787a1f9c8e4759ae0fcc218f37d2d;hpb=7b4828b68ced7e92a3399f9e48da8726b6b315f0 diff --git a/src/tt.cpp b/src/tt.cpp index 117b6002..2979c104 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -54,7 +54,7 @@ void TranspositionTable::resize(size_t mbSize) { /// TranspositionTable::clear() overwrites the entire transposition table -/// with zeroes. It is called whenever the table is resized, or when the +/// with zeros. It is called whenever the table is resized, or when the /// user asks the program to clear the table (from the UCI interface). void TranspositionTable::clear() { @@ -64,47 +64,28 @@ void TranspositionTable::clear() { /// 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* const tte = first_entry(key); - const uint16_t key16 = key >> 48; - - for (unsigned i = 0; i < TTClusterSize; ++i) - if (tte[i].key16 == key16) - { - tte[i].genBound8 = uint8_t(generation | tte[i].bound()); // Refresh - return &tte[i]; - } - - 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 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 +/// transposition table. It returns true and a pointer to the TTEntry if +/// the position is found. Otherwise, it returns false and a pointer to an empty or +/// least valuable TTEntry to be replaced later. 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) { +TTEntry* TranspositionTable::probe(const Key key, bool& found) const { TTEntry* const tte = first_entry(key); - const uint16_t key16 = key >> 48; // Use the high 16 bits as key inside the cluster + const uint16_t key16 = key >> 48; // Use the high 16 bits as key inside the cluster for (unsigned i = 0; i < TTClusterSize; ++i) - if (!tte[i].key16 || tte[i].key16 == key16) // Empty or overwrite old + if (!tte[i].key16 || tte[i].key16 == key16) { - // Save preserving any existing ttMove - tte[i].save(key16, v, b, d, m ? m : tte[i].move(), generation, statV); - return; + if (tte[i].key16) + tte[i].genBound8 = uint8_t(generation | tte[i].bound()); // Refresh + + found = (bool)tte[i].key16; + return &tte[i]; } - // Implement replace strategy + // Find an entry to be replaced according to the replacement strategy TTEntry* replace = tte; for (unsigned i = 1; i < TTClusterSize; ++i) if ( (( tte[i].genBound8 & 0xFC) == generation || tte[i].bound() == BOUND_EXACT) @@ -112,5 +93,6 @@ void TranspositionTable::store(const Key key, Value v, Bound b, Depth d, Move m, - (tte[i].depth8 < replace->depth8) < 0) replace = &tte[i]; - replace->save(key16, v, b, d, m, generation, statV); + found = false; + return replace; }