X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=1959693258c3d8e0e6dbad995103ed0ee766cbe2;hp=146e591f4462f5cb612b9a7e18d6dec190f8c5c6;hb=a230dc14045691667ffce46619de60497edceb88;hpb=7c93b171cba0ff58cb679846cde82e6564b5b45b diff --git a/src/tt.cpp b/src/tt.cpp index 146e591f..19596932 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -6,12 +6,12 @@ it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. - + Glaurung is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - + You should have received a copy of the GNU General Public License along with this program. If not, see . */ @@ -105,23 +105,29 @@ void TranspositionTable::store(const Position &pos, Value v, Depth d, Move m, ValueType type) { TTEntry *tte, *replace; - tte = replace = entries + int(pos.get_key() & (size - 1)) * 4; + tte = replace = first_entry(pos); for (int i = 0; i < 4; i++) { - if ((tte+i)->key() == pos.get_key()) + if (!(tte+i)->key()) // still empty { - if (m == MOVE_NONE) - m = (tte+i)->move(); - *(tte+i) = TTEntry(pos.get_key(), v, type, d, m, generation); + writes++; return; } - if (replace->generation() == generation) + if ((tte+i)->key() == pos.get_key()) // overwrite old { - if ((tte+i)->generation() != generation || (tte+i)->depth() < replace->depth()) - replace = tte+i; + if (m == MOVE_NONE) + m = (tte+i)->move(); + + *(tte+i) = TTEntry(pos.get_key(), v, type, d, m, generation); + return; } - else if ((tte+i)->generation() != generation && (tte+i)->depth() < replace->depth()) + if ( i == 0 // already is (replace == tte+i), common case + || replace->generation() < (tte+i)->generation()) + continue; + + if ( replace->generation() > (tte+i)->generation() + || (tte+i)->depth() < replace->depth()) replace = tte+i; } *replace = TTEntry(pos.get_key(), v, type, d, m, generation); @@ -130,35 +136,31 @@ void TranspositionTable::store(const Position &pos, Value v, Depth d, /// TranspositionTable::retrieve looks up the current position in the -/// transposition table, and extracts the value, value type, depth and -/// best move if the position is found. The return value is true if -/// the position is found, and false if it isn't. - -bool TranspositionTable::retrieve(const Position &pos, Value *value, - Depth *d, Move *move, - ValueType *type) const { - TTEntry *tte; - bool found = false; - - tte = entries + int(pos.get_key() & (size - 1)) * 4; - for (int i = 0; i < 4 && !found ; i++) - if ((tte+i)->key() == pos.get_key()) - { - tte = tte + i; - found = true; - } - if (!found) { - *move = MOVE_NONE; - return false; +/// transposition table. Returns a pointer to the TTEntry or NULL +/// if position is not found. + +const TTEntry* TranspositionTable::retrieve(const Position &pos) const { + + TTEntry *tte = first_entry(pos); + + for (int i = 0; i < 4; i++) + { + tte += i; + if (tte->key() == pos.get_key()) + return tte; } - *value = tte->value(); - *type = tte->type(); - *d = tte->depth(); - *move = tte->move(); - return true; + return NULL; } +/// TranspositionTable::first_entry returns a pointer to the first +/// entry of a cluster given a position. + +inline TTEntry* TranspositionTable::first_entry(const Position &pos) const { + + return entries + (int(pos.get_key() & (size - 1)) << 2); +} + /// 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 @@ -171,7 +173,7 @@ void TranspositionTable::new_search() { } -/// TranspositionTable::insert_pv() is called at the end of a search +/// TranspositionTable::insert_pv() is called at the end of a search /// iteration, and inserts the PV back into the PV. This makes sure the /// old PV moves are searched first, even if the old TT entries have been /// overwritten. @@ -206,36 +208,9 @@ TTEntry::TTEntry() { } TTEntry::TTEntry(Key k, Value v, ValueType t, Depth d, Move m, - int generation) { - key_ = k; - data = (m & 0x7FFFF) | (t << 20) | (generation << 23); - value_ = v; - depth_ = int16_t(d); -} + int generation) : + key_ (k), data((m & 0x7FFFF) | (t << 20) | (generation << 23)), + value_(v), depth_(int16_t(d)) {} -/// Functions for extracting data from TTEntry objects. - -inline Key TTEntry::key() const { - return key_; -} - -inline Depth TTEntry::depth() const { - return Depth(depth_); -} -inline Move TTEntry::move() const { - return Move(data & 0x7FFFF); -} - -inline Value TTEntry::value() const { - return Value(value_); -} - -inline ValueType TTEntry::type() const { - return ValueType((data >> 20) & 3); -} - -inline int TTEntry::generation() const { - return (data >> 23); -}