size_t cnt = 0;
CheckInfo ci(pos);
- for (MoveList<LEGAL> it(pos); !it.end(); ++it)
+ for (MoveList<LEGAL> it(pos); *it; ++it)
{
pos.do_move(*it, st, ci, pos.move_gives_check(*it, ci));
cnt += perft(pos, depth - ONE_PLY);
split_point_start: // At split points actual search starts from here
- MovePicker mp(pos, ttMove, depth, History, Countermoves, ss, PvNode ? -VALUE_INFINITE : beta);
+ Square prevMoveSq = to_sq((ss-1)->currentMove);
+ Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first,
+ Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].second };
+
+ MovePicker mp(pos, ttMove, depth, History, countermoves, ss, PvNode ? -VALUE_INFINITE : beta);
CheckInfo ci(pos);
value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
singularExtensionNode = !RootNode
&& move != ss->killers[1])
{
ss->reduction = reduction<PvNode>(depth, moveCount);
+ if (move == countermoves[0] || move == countermoves[1])
+ ss->reduction = std::max(DEPTH_ZERO, ss->reduction-ONE_PLY);
+
Depth d = std::max(newDepth - ss->reduction, ONE_PLY);
if (SpNode)
alpha = splitPoint->alpha;
Value bonus = Value(int(depth) * int(depth));
History.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus);
if (is_ok((ss-1)->currentMove))
- {
- Square prevSq = to_sq((ss-1)->currentMove);
- Countermoves.update(pos.piece_on(prevSq), prevSq, bestMove);
- }
+ Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, bestMove);
// Decrease history of all the other played non-capture moves
for (int i = 0; i < playedMoveCount - 1; i++)