Stack ss[PLY_MAX_PLUS_2];
int bestMoveChanges[PLY_MAX_PLUS_2];
- int depth, delta;
- Value bestValue, alpha, beta;
+ int depth;
+ Value bestValue, alpha, beta, delta;
Move bestMove, skillBest, skillPonder;
bool bestMoveNeverChanged = true;
H.clear();
RootMoves.clear();
*ponderMove = bestMove = skillBest = skillPonder = MOVE_NONE;
- depth = delta = 0;
- bestValue = alpha = -VALUE_INFINITE, beta = VALUE_INFINITE;
+ depth = 0;
+ bestValue = alpha = -VALUE_INFINITE, beta = delta = VALUE_INFINITE;
ss->currentMove = MOVE_NULL; // Hack to skip update gains
for (MoveList<MV_LEGAL> ml(pos); !ml.end(); ++ml)
for (MultiPVIdx = 0; MultiPVIdx < std::min(MultiPV, RootMoves.size()); MultiPVIdx++)
{
// Calculate dynamic aspiration window based on previous iteration
- if (depth >= 5 && abs(RootMoves[MultiPVIdx].score) < VALUE_KNOWN_WIN)
+ if (depth >= 5 && abs(RootMoves[MultiPVIdx].prevScore) < VALUE_KNOWN_WIN)
{
- delta = abs(RootMoves[MultiPVIdx].score - RootMoves[MultiPVIdx].prevScore);
- delta = std::min(std::max(delta, 16), 24);
- delta = (delta + 7) / 8 * 8; // Round to match grainSize
-
- alpha = RootMoves[MultiPVIdx].score - delta;
- beta = RootMoves[MultiPVIdx].score + delta;
-
- assert(alpha > -VALUE_INFINITE && beta < VALUE_INFINITE);
+ delta = Value(16);
+ alpha = RootMoves[MultiPVIdx].prevScore - delta;
+ beta = RootMoves[MultiPVIdx].prevScore + delta;
}
else
{
// research, otherwise exit the fail high/low loop.
if (bestValue >= beta)
{
- beta = std::min(beta + delta, VALUE_INFINITE);
+ beta += delta;
delta += delta / 2;
}
else if (bestValue <= alpha)
Signals.failedLowAtRoot = true;
Signals.stopOnPonderhit = false;
- alpha = std::max(alpha - delta, -VALUE_INFINITE);
+ alpha -= delta;
delta += delta / 2;
}
else
break;
+ assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
+
} while (abs(bestValue) < VALUE_KNOWN_WIN);
}