Value bestValue, alpha, beta, delta;
memset(ss-1, 0, 4 * sizeof(Stack));
- depth = BestMoveChanges = 0;
- bestValue = delta = -VALUE_INFINITE;
(ss-1)->currentMove = MOVE_NULL; // Hack to skip update gains
+
+ depth = BestMoveChanges = 0;
+ bestValue = delta = alpha = -VALUE_INFINITE;
+ beta = VALUE_INFINITE;
+
TT.new_search();
History.clear();
Gains.clear();
// MultiPV loop. We perform a full root search for each PV line
for (PVIdx = 0; PVIdx < PVSize; PVIdx++)
{
- // Set aspiration window default width
- if (depth >= 5 && abs(RootMoves[PVIdx].prevScore) < VALUE_KNOWN_WIN)
+ // Reset aspiration window starting size
+ if (depth >= 5)
{
delta = Value(16);
alpha = RootMoves[PVIdx].prevScore - delta;
beta = RootMoves[PVIdx].prevScore + delta;
}
- else
- {
- alpha = -VALUE_INFINITE;
- beta = VALUE_INFINITE;
- }
// Start with a small aspiration window and, in case of fail high/low,
// research with bigger window until not failing high/low anymore.
// In case of failing high/low increase aspiration window and
// research, otherwise exit the loop.
- if (bestValue > alpha && bestValue < beta)
- break;
-
- // Give some update (without cluttering the UI) before to research
- if (Time::now() - SearchTime > 3000)
- sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
-
- if (abs(bestValue) >= VALUE_KNOWN_WIN)
- {
- alpha = -VALUE_INFINITE;
- beta = VALUE_INFINITE;
- }
- else if (bestValue >= beta)
- {
+ if (bestValue >= beta)
beta += delta;
- delta += delta / 2;
- }
- else
+
+ else if (bestValue <= alpha)
{
+ alpha -= delta;
+
Signals.failedLowAtRoot = true;
Signals.stopOnPonderhit = false;
-
- alpha -= delta;
- delta += delta / 2;
}
+ else
+ break;
+
+ delta += delta / 2;
assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
+
+ // Give some update (without cluttering the UI) before to research
+ if (Time::now() - SearchTime > 3000)
+ sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
}
// Sort the PV lines searched so far and update the GUI