uint64_t perft(Position& pos, Depth depth) {
StateInfo st;
+ ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
uint64_t cnt, nodes = 0;
const bool leaf = (depth == 2);
void Search::init() {
for (int i = 1; i < MAX_MOVES; ++i)
- Reductions[i] = int((22.0 + std::log(Threads.size())) * std::log(i));
+ Reductions[i] = int((22.0 + 2 * std::log(Threads.size())) * std::log(i + 0.25 * std::log(i)));
}
Time.init(Limits, us, rootPos.game_ply());
TT.new_search();
- Eval::verify_NNUE();
+ Eval::NNUE::verify();
if (rootMoves.empty())
{
// Start with a small aspiration window and, in the case of a fail
// high/low, re-search with a bigger window until we don't fail
// high/low anymore.
- int failedHighCnt = 0;
+ failedHighCnt = 0;
while (true)
{
Depth adjustedDepth = std::max(1, rootDepth - failedHighCnt - searchAgainCounter);
++failedHighCnt;
}
else
- {
- ++rootMoves[pvIdx].bestMoveCount;
break;
- }
delta += delta / 4 + 5;
}
double bestMoveInstability = 1 + 2 * totBestMoveChanges / Threads.size();
- double totalTime = rootMoves.size() == 1 ? 0 :
- Time.optimum() * fallingEval * reduction * bestMoveInstability;
+ double totalTime = Time.optimum() * fallingEval * reduction * bestMoveInstability;
- // Stop the search if we have exceeded the totalTime, at least 1ms search
+ // Cap used time in case of a single legal move for a better viewer experience in tournaments
+ // yielding correct scores and sufficiently fast moves.
+ if (rootMoves.size() == 1)
+ totalTime = std::min(500.0, totalTime);
+
+ // Stop the search if we have exceeded the totalTime
if (Time.elapsed() > totalTime)
{
// If we are allowed to ponder do not stop the search now but
constexpr bool PvNode = NT == PV;
const bool rootNode = PvNode && ss->ply == 0;
+ const Depth maxNextDepth = rootNode ? depth : depth + 1;
// Check if we have an upcoming move which draws by repetition, or
// if the opponent had an alternative move earlier to this position.
Move pv[MAX_PLY+1], capturesSearched[32], quietsSearched[64];
StateInfo st;
+ ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
TTEntry* tte;
Key posKey;
Move ttMove, move, excludedMove, bestMove;
assert(eval - beta >= 0);
// Null move dynamic reduction based on depth and value
- Depth R = (817 + 71 * depth) / 213 + std::min(int(eval - beta) / 192, 3);
+ Depth R = (982 + 85 * depth) / 256 + std::min(int(eval - beta) / 192, 3);
ss->currentMove = MOVE_NULL;
ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
&& captureHistory[movedPiece][to_sq(move)][type_of(pos.piece_on(to_sq(move)))] < 0)
continue;
- // Futility pruning for captures
- if ( !givesCheck
- && lmrDepth < 6
- && !(PvNode && abs(bestValue) < 2)
- && PieceValue[MG][type_of(movedPiece)] >= PieceValue[MG][type_of(pos.piece_on(to_sq(move)))]
- && !ss->inCheck
- && ss->staticEval + 169 + 244 * lmrDepth
- + PieceValue[MG][type_of(pos.piece_on(to_sq(move)))] <= alpha)
- continue;
-
// See based pruning
if (!pos.see_ge(move, Value(-221) * depth)) // (~25 Elo)
continue;
// Step 16. Reduced depth search (LMR, ~200 Elo). If the move fails high it will be
// re-searched at full depth.
if ( depth >= 3
- && moveCount > 1 + 2 * rootNode + 2 * (PvNode && abs(bestValue) < 2)
+ && moveCount > 1 + 2 * rootNode
&& ( !captureOrPromotion
|| moveCountPruning
|| ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
if (ttCapture)
r++;
+ // Increase reduction at root if failing high
+ r += rootNode ? thisThread->failedHighCnt * thisThread->failedHighCnt * moveCount / 512 : 0;
+
// Increase reduction for cut nodes (~10 Elo)
if (cutNode)
r += 2;
}
else
{
- // Increase reduction for captures/promotions if late move and at low depth
- if (depth < 8 && moveCount > 2)
- r++;
-
- // Unless giving check, this capture is likely bad
- if ( !givesCheck
- && ss->staticEval + PieceValue[EG][pos.captured_piece()] + 213 * depth <= alpha)
- r++;
+ // Increase reduction for captures/promotions if late move and at low depth
+ if (depth < 8 && moveCount > 2)
+ r++;
+
+ // Unless giving check, this capture is likely bad
+ if ( !givesCheck
+ && ss->staticEval + PieceValue[EG][pos.captured_piece()] + 213 * depth <= alpha)
+ r++;
}
Depth d = std::clamp(newDepth - r, 1, newDepth);
(ss+1)->pv = pv;
(ss+1)->pv[0] = MOVE_NONE;
- value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, false);
+ value = -search<PV>(pos, ss+1, -beta, -alpha,
+ std::min(maxNextDepth, newDepth), false);
}
// Step 18. Undo move
Move pv[MAX_PLY+1];
StateInfo st;
+ ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
TTEntry* tte;
Key posKey;
Move ttMove, move, bestMove;
[pos.moved_piece(move)]
[to_sq(move)];
+ // CounterMove based pruning
if ( !captureOrPromotion
- && moveCount
+ && bestValue > VALUE_TB_LOSS_IN_MAX_PLY
&& (*contHist[0])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold
&& (*contHist[1])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold)
continue;
// All legal moves have been searched. A special case: if we're in check
// and no legal moves were found, it is checkmate.
if (ss->inCheck && bestValue == -VALUE_INFINITE)
+ {
+ assert(!MoveList<LEGAL>(pos).size());
+
return mated_in(ss->ply); // Plies to mate from the root
+ }
tte->save(posKey, value_to_tt(bestValue, ss->ply), pvHit,
bestValue >= beta ? BOUND_LOWER :
bool RootMove::extract_ponder_from_tt(Position& pos) {
StateInfo st;
+ ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
bool ttHit;
assert(pv.size() == 1);
projects / stockfish / blobdiff