TranspositionTable::TranspositionTable() {
- size = writes = 0;
+ size = overwrites = 0;
entries = 0;
generation = 0;
}
void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d, Move m, Value statV, Value kingD) {
+ int c1, c2, c3;
TTEntry *tte, *replace;
uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key
tte->save(posKey32, v, t, d, m, generation, statV, kingD);
return;
}
- else if (i == 0) // replace would be a no-op in this common case
+
+ 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);
+ c1 = (replace->generation() == generation ? 2 : 0);
+ c2 = (tte->generation() == generation ? -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);
- writes++;
+ overwrites++;
}
void TranspositionTable::new_search() {
generation++;
- writes = 0;
+ overwrites = 0;
}
/// will often get single-move PVs when the search stops while failing high,
/// and a single-move PV means that we don't have a ponder move.
-void TranspositionTable::extract_pv(const Position& pos, Move pv[], const int PLY_MAX) {
+void TranspositionTable::extract_pv(const Position& pos, Move bestMove, Move pv[], const int PLY_MAX) {
const TTEntry* tte;
StateInfo st;
Position p(pos, pos.thread());
int ply = 0;
- // Update position to the end of current PV
- while (pv[ply] != MOVE_NONE)
- p.do_move(pv[ply++], st);
+ assert(bestMove != MOVE_NONE);
+
+ pv[ply] = bestMove;
+ p.do_move(pv[ply++], st);
- // Try to add moves from TT while possible
+ // Extract moves from TT when possible. We try hard to always
+ // get a ponder move, that's the reason of ply < 2 conditions.
while ( (tte = retrieve(p.get_key())) != NULL
&& tte->move() != MOVE_NONE
+ && (tte->type() == VALUE_TYPE_EXACT || ply < 2)
&& move_is_legal(p, tte->move())
&& (!p.is_draw() || ply < 2)
&& ply < PLY_MAX)
/// TranspositionTable::full() returns the permill of all transposition table
-/// entries which have received at least one write during the current search.
+/// entries which have received at least one overwrite during the current search.
/// It is used to display the "info hashfull ..." information in UCI.
int TranspositionTable::full() const {
double N = double(size) * ClusterSize;
- return int(1000 * (1 - exp(writes * log(1.0 - 1.0/N))));
+ return int(1000 * (1 - exp(overwrites * log(1.0 - 1.0/N))));
}