X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.cpp;h=83eaf800ac480aabd64856c5d02ac3b27d8cffa5;hp=d7037a300f9aea657ac3d1ca69dc756a68abe822;hb=aabd526f7c9cec1d1f6a8f7da738311487aa42b8;hpb=5dc23121215039938a9ef4e59ae934312774571c diff --git a/src/tt.cpp b/src/tt.cpp index d7037a30..83eaf800 100644 --- a/src/tt.cpp +++ b/src/tt.cpp @@ -24,6 +24,7 @@ #include #include +#include #include "tt.h" @@ -32,20 +33,13 @@ //// Functions //// -/// Constructor +TranspositionTable::TranspositionTable() { -TranspositionTable::TranspositionTable(unsigned mbSize) { - - size = 0; - generation = 0; - writes = 0; + size = writes = 0; entries = 0; - set_size(mbSize); + generation = 0; } - -/// Destructor - TranspositionTable::~TranspositionTable() { delete [] entries; @@ -57,33 +51,33 @@ TranspositionTable::~TranspositionTable() { void TranspositionTable::set_size(unsigned mbSize) { - assert(mbSize >= 4 && mbSize <= 1024); + assert(mbSize >= 4 && mbSize <= 4096); unsigned newSize = 1024; // We store a cluster of 4 TTEntry for each position and newSize is // the maximum number of storable positions - for ( ; newSize * 4 * (sizeof(TTEntry)) <= (mbSize << 20); newSize *= 2); - newSize /= 2; + while ((2 * newSize) * 4 * (sizeof(TTEntry)) <= (mbSize << 20)) + newSize *= 2; + if (newSize != size) { - size = newSize; - delete [] entries; - entries = new TTEntry[size * 4]; - if (!entries) - { - std::cerr << "Failed to allocate " << mbSize - << " MB for transposition table." - << std::endl; - exit(EXIT_FAILURE); - } - clear(); + size = newSize; + delete [] entries; + entries = new TTEntry[size * 4]; + if (!entries) + { + std::cerr << "Failed to allocate " << mbSize + << " MB for transposition table." << std::endl; + exit(EXIT_FAILURE); + } + clear(); } } /// TranspositionTable::clear overwrites the entire transposition table -/// with zeroes. It is called whenever the table is resized, or when the +/// with zeroes. It is called whenever the table is resized, or when the /// user asks the program to clear the table (from the UCI interface). /// Perhaps we should also clear it when the "ucinewgame" command is recieved? @@ -95,43 +89,44 @@ void TranspositionTable::clear() { /// TranspositionTable::store writes a new entry containing a position, /// a value, a value type, a search depth, and a best move to the -/// transposition table. The transposition table is organized in clusters -/// of four TTEntry objects, and when a new entry is written, it replaces -/// the least valuable of the four entries in a cluster. A TTEntry t1 is +/// transposition table. Transposition table is organized in clusters of +/// four TTEntry objects, and when a new entry is written, it replaces +/// the least valuable of the four entries in a cluster. 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. +/// is bigger than the depth of t2. A TTEntry of type VALUE_TYPE_EVAL +/// never replaces another entry for the same position. + +void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, Move m) { -void TranspositionTable::store(const Position &pos, Value v, Depth d, - Move m, ValueType type) { TTEntry *tte, *replace; - tte = replace = first_entry(pos); - for (int i = 0; i < 4; i++) + tte = replace = first_entry(posKey); + for (int i = 0; i < 4; i++, tte++) { - if (!(tte+i)->key()) // still empty - { - *(tte+i) = TTEntry(pos.get_key(), v, type, d, m, generation); - writes++; - return; - } - if ((tte+i)->key() == pos.get_key()) // overwrite old - { - if (m == MOVE_NONE) - m = (tte+i)->move(); - - *(tte+i) = TTEntry(pos.get_key(), v, type, d, m, generation); - return; - } - 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; + if (!tte->key() || tte->key() == posKey) // empty or overwrite old + { + // Do not overwrite when new type is VALUE_TYPE_EVAL + if (tte->key() && t == VALUE_TYPE_EVAL) + return; + + if (m == MOVE_NONE) + m = tte->move(); + + *tte = TTEntry(posKey, v, t, d, m, generation); + return; + } + else if (i == 0) // replace would be a no-op in this common case + continue; + + int c1 = (replace->generation() == generation ? 2 : 0); + int c2 = (tte->generation() == generation ? -2 : 0); + int c3 = (tte->depth() < replace->depth() ? 1 : 0); + + if (c1 + c2 + c3 > 0) + replace = tte; } - *replace = TTEntry(pos.get_key(), v, type, d, m, generation); + *replace = TTEntry(posKey, v, t, d, m, generation); writes++; } @@ -140,16 +135,14 @@ void TranspositionTable::store(const Position &pos, Value v, Depth d, /// transposition table. Returns a pointer to the TTEntry or NULL /// if position is not found. -const TTEntry* TranspositionTable::retrieve(const Position &pos) const { +TTEntry* TranspositionTable::retrieve(const Key posKey) const { - TTEntry *tte = first_entry(pos); + TTEntry *tte = first_entry(posKey); - for (int i = 0; i < 4; i++) - { - tte += i; - if (tte->key() == pos.get_key()) + for (int i = 0; i < 4; i++, tte++) + if (tte->key() == posKey) return tte; - } + return NULL; } @@ -157,13 +150,13 @@ const TTEntry* TranspositionTable::retrieve(const Position &pos) const { /// 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 { +inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { - return entries + (int(pos.get_key() & (size - 1)) << 2); + return entries + (int(posKey & (size - 1)) << 2); } /// TranspositionTable::new_search() is called at the beginning of every new -/// search. It increments the "generation" variable, which is used to +/// search. It increments the "generation" variable, which is used to /// distinguish transposition table entries from previous searches from /// entries from the current search. @@ -175,19 +168,19 @@ void TranspositionTable::new_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. +/// 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. -void TranspositionTable::insert_pv(const Position &pos, Move pv[]) { +void TranspositionTable::insert_pv(const Position& pos, Move pv[]) { - UndoInfo u; + StateInfo st; Position p(pos); for (int i = 0; pv[i] != MOVE_NONE; i++) { - store(p, VALUE_NONE, Depth(0), pv[i], VALUE_TYPE_NONE); - p.do_move(pv[i], u); + store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i]); + p.do_move(pv[i], st); } } @@ -196,22 +189,8 @@ void TranspositionTable::insert_pv(const Position &pos, Move pv[]) { /// entries which have received at least one write during the current search. /// It is used to display the "info hashfull ..." information in UCI. -int TranspositionTable::full() { +int TranspositionTable::full() const { double N = double(size) * 4.0; return int(1000 * (1 - exp(writes * log(1.0 - 1.0/N)))); } - - -/// Constructors - -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)) {} - - -