namespace Search {
- volatile SignalsType Signals;
+ SignalsType Signals;
LimitsType Limits;
StateStackPtr SetupStates;
}
enum NodeType { Root, PV, NonPV };
// Razoring and futility margin based on depth
- int razor_margin[4] = {483, 570, 603, 554};
+ const int razor_margin[4] = { 483, 570, 603, 554 };
Value futility_margin(Depth d) { return Value(200 * d); }
// Futility and reductions lookup tables, initialized at startup
};
EasyMoveManager EasyMove;
+ bool easyPlayed, failedLow;
double BestMoveChanges;
Value DrawValue[COLOR_NB];
CounterMovesHistoryStats CounterMovesHistory;
Value value_from_tt(Value v, int ply);
void update_pv(Move* pv, Move move, Move* childPv);
void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt);
+ void check_time();
} // namespace
}
-/// Search::reset() clears all search memory, to obtain reproducible search results
+/// Search::clear() resets to zero search state, to obtain reproducible results
-void Search::reset () {
+void Search::clear() {
TT.clear();
CounterMovesHistory.clear();
for (Thread* th : Threads)
{
- th->History.clear();
- th->Countermoves.clear();
+ th->history.clear();
+ th->counterMoves.clear();
}
}
return nodes;
}
-template uint64_t Search::perft<true>(Position& pos, Depth depth);
+template uint64_t Search::perft<true>(Position&, Depth);
-/// MainThread::think() is called by the main thread when the program receives
+/// MainThread::search() is called by the main thread when the program receives
/// the UCI 'go' command. It searches from root position and at the end prints
/// the "bestmove" to output.
-void MainThread::think() {
+void MainThread::search() {
Color us = rootPos.side_to_move();
Time.init(Limits, us, rootPos.game_ply());
for (Thread* th : Threads)
{
th->maxPly = 0;
- th->depth = DEPTH_ZERO;
- th->searching = true;
+ th->rootDepth = DEPTH_ZERO;
if (th != this)
{
th->rootPos = Position(rootPos, th);
th->rootMoves = rootMoves;
- th->notify_one(); // Wake up the thread and start searching
+ th->start_searching();
}
}
- Threads.timer->run = true;
- Threads.timer->notify_one(); // Start the recurring timer
-
- search(true); // Let's start searching!
-
- // Stop the threads and the timer
- Signals.stop = true;
- Threads.timer->run = false;
-
- // Wait until all threads have finished
- for (Thread* th : Threads)
- if (th != this)
- th->wait_while(th->searching);
+ Thread::search(); // Let's start searching!
}
// When playing in 'nodes as time' mode, subtract the searched nodes from
wait(Signals.stop);
}
- sync_cout << "bestmove " << UCI::move(rootMoves[0].pv[0], rootPos.is_chess960());
+ // Stop the threads if not already stopped
+ Signals.stop = true;
+
+ // Wait until all threads have finished
+ for (Thread* th : Threads)
+ if (th != this)
+ th->wait_for_search_finished();
+
+ // Check if there are threads with a better score than main thread.
+ Thread* bestThread = this;
+ if (!easyPlayed && Options["MultiPV"] == 1 && !Skill(Options["Skill Level"]).enabled())
+ for (Thread* th : Threads)
+ if ( th->completedDepth > bestThread->completedDepth
+ && th->rootMoves[0].score > bestThread->rootMoves[0].score)
+ bestThread = th;
- if (rootMoves[0].pv.size() > 1 || rootMoves[0].extract_ponder_from_tt(rootPos))
- std::cout << " ponder " << UCI::move(rootMoves[0].pv[1], rootPos.is_chess960());
+ // Send new PV when needed.
+ // FIXME: Breaks multiPV, and skill levels
+ if (bestThread != this)
+ sync_cout << UCI::pv(bestThread->rootPos, bestThread->completedDepth, -VALUE_INFINITE, VALUE_INFINITE) << sync_endl;
+
+ sync_cout << "bestmove " << UCI::move(bestThread->rootMoves[0].pv[0], rootPos.is_chess960());
+
+ if (bestThread->rootMoves[0].pv.size() > 1 || bestThread->rootMoves[0].extract_ponder_from_tt(rootPos))
+ std::cout << " ponder " << UCI::move(bestThread->rootMoves[0].pv[1], rootPos.is_chess960());
std::cout << sync_endl;
}
// repeatedly with increasing depth until the allocated thinking time has been
// consumed, user stops the search, or the maximum search depth is reached.
-void Thread::search(bool isMainThread) {
+void Thread::search() {
- Stack* ss = stack + 2; // To allow referencing (ss-2) and (ss+2)
+ Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
Value bestValue, alpha, beta, delta;
Move easyMove = MOVE_NONE;
+ bool isMainThread = (this == Threads.main());
std::memset(ss-2, 0, 5 * sizeof(Stack));
bestValue = delta = alpha = -VALUE_INFINITE;
beta = VALUE_INFINITE;
+ completedDepth = DEPTH_ZERO;
if (isMainThread)
{
easyMove = EasyMove.get(rootPos.key());
EasyMove.clear();
+ easyPlayed = false;
BestMoveChanges = 0;
TT.new_search();
}
multiPV = std::min(multiPV, rootMoves.size());
// Iterative deepening loop until requested to stop or target depth reached
- while (++depth < DEPTH_MAX && !Signals.stop && (!Limits.depth || depth <= Limits.depth))
+ while (++rootDepth < DEPTH_MAX && !Signals.stop && (!Limits.depth || rootDepth <= Limits.depth))
{
- // Set up the new depth for the helper threads
+ // Set up the new depth for the helper threads skipping in average each
+ // 2nd ply (using a half density map similar to a Hadamard matrix).
if (!isMainThread)
- depth = Threads.main()->depth + Depth(int(3 * log(1 + this->idx)));
+ {
+ int d = rootDepth + rootPos.game_ply();
+
+ if (idx <= 6 || idx > 24)
+ {
+ if (((d + idx) >> (msb(idx + 1) - 1)) % 2)
+ continue;
+ }
+ else
+ {
+ // Table of values of 6 bits with 3 of them set
+ static const int HalfDensityMap[] = {
+ 0x07, 0x0b, 0x0d, 0x0e, 0x13, 0x16, 0x19, 0x1a, 0x1c,
+ 0x23, 0x25, 0x26, 0x29, 0x2c, 0x31, 0x32, 0x34, 0x38
+ };
+
+ if ((HalfDensityMap[idx - 7] >> (d % 6)) & 1)
+ continue;
+ }
+ }
// Age out PV variability metric
if (isMainThread)
- BestMoveChanges *= 0.5;
+ BestMoveChanges *= 0.505, failedLow = false;
// Save the last iteration's scores before first PV line is searched and
// all the move scores except the (new) PV are set to -VALUE_INFINITE.
for (PVIdx = 0; PVIdx < multiPV && !Signals.stop; ++PVIdx)
{
// Reset aspiration window starting size
- if (depth >= 5 * ONE_PLY)
+ if (rootDepth >= 5 * ONE_PLY)
{
delta = Value(18);
alpha = std::max(rootMoves[PVIdx].previousScore - delta,-VALUE_INFINITE);
// high/low anymore.
while (true)
{
- bestValue = ::search<Root>(rootPos, ss, alpha, beta, depth, false);
+ bestValue = ::search<Root>(rootPos, ss, alpha, beta, rootDepth, false);
// Bring the best move to the front. It is critical that sorting
// is done with a stable algorithm because all the values but the
&& multiPV == 1
&& (bestValue <= alpha || bestValue >= beta)
&& Time.elapsed() > 3000)
- sync_cout << UCI::pv(rootPos, depth, alpha, beta) << sync_endl;
+ sync_cout << UCI::pv(rootPos, rootDepth, alpha, beta) << sync_endl;
// In case of failing low/high increase aspiration window and
// re-search, otherwise exit the loop.
if (isMainThread)
{
- Signals.failedLowAtRoot = true;
+ failedLow = true;
Signals.stopOnPonderhit = false;
}
}
<< " time " << Time.elapsed() << sync_endl;
else if (PVIdx + 1 == multiPV || Time.elapsed() > 3000)
- sync_cout << UCI::pv(rootPos, depth, alpha, beta) << sync_endl;
+ sync_cout << UCI::pv(rootPos, rootDepth, alpha, beta) << sync_endl;
}
+ if (!Signals.stop)
+ completedDepth = rootDepth;
+
if (!isMainThread)
continue;
// If skill level is enabled and time is up, pick a sub-optimal best move
- if (skill.enabled() && skill.time_to_pick(depth))
+ if (skill.enabled() && skill.time_to_pick(rootDepth))
skill.pick_best(multiPV);
// Have we found a "mate in x"?
if (!Signals.stop && !Signals.stopOnPonderhit)
{
// Take some extra time if the best move has changed
- if (depth > 4 * ONE_PLY && multiPV == 1)
+ if (rootDepth > 4 * ONE_PLY && multiPV == 1)
Time.pv_instability(BestMoveChanges);
// Stop the search if only one legal move is available or all
// of the available time has been used or we matched an easyMove
// from the previous search and just did a fast verification.
if ( rootMoves.size() == 1
- || Time.elapsed() > Time.available()
- || ( rootMoves[0].pv[0] == easyMove
+ || Time.elapsed() > Time.available() * (failedLow? 641 : 315)/640
+ || ( easyPlayed = ( rootMoves[0].pv[0] == easyMove
&& BestMoveChanges < 0.03
- && Time.elapsed() > Time.available() / 10))
+ && Time.elapsed() > Time.available() / 8)))
{
// If we are allowed to ponder do not stop the search now but
// keep pondering until the GUI sends "ponderhit" or "stop".
}
}
- searching = false;
- notify_one(); // Wake up main thread if is sleeping waiting for us
-
if (!isMainThread)
return;
// Clear any candidate easy move that wasn't stable for the last search
// iterations; the second condition prevents consecutive fast moves.
- if (EasyMove.stableCnt < 6 || Time.elapsed() < Time.available())
+ if (EasyMove.stableCnt < 6 || easyPlayed)
EasyMove.clear();
// If skill level is enabled, swap best PV line with the sub-optimal one
namespace {
- // search<>() is the main search function for both PV and non-PV nodes and for
- // normal and SplitPoint nodes. When called just after a split point the search
- // is simpler because we have already probed the hash table, done a null move
- // search, and searched the first move before splitting, so we don't have to
- // repeat all this work again. We also don't need to store anything to the hash
- // table here: This is taken care of after we return from the split point.
+ // search<>() is the main search function for both PV and non-PV nodes
template <NodeType NT>
Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode) {
assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE);
assert(PvNode || (alpha == beta - 1));
- assert(depth > DEPTH_ZERO);
+ assert(DEPTH_ZERO < depth && depth < DEPTH_MAX);
Move pv[MAX_PLY+1], quietsSearched[64];
StateInfo st;
bestValue = -VALUE_INFINITE;
ss->ply = (ss-1)->ply + 1;
+ // Check for available remaining time
+ if (thisThread->resetCalls.load(std::memory_order_relaxed))
+ {
+ thisThread->resetCalls = false;
+ thisThread->callsCnt = 0;
+ }
+ if (++thisThread->callsCnt > 4096)
+ {
+ for (Thread* th : Threads)
+ th->resetCalls = true;
+
+ check_time();
+ }
+
// Used to send selDepth info to GUI
if (PvNode && thisThread->maxPly < ss->ply)
thisThread->maxPly = ss->ply;
if (!RootNode)
{
// Step 2. Check for aborted search and immediate draw
- if (Signals.stop || pos.is_draw() || ss->ply >= MAX_PLY)
- return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos) : DrawValue[pos.side_to_move()];
+ if (Signals.stop.load(std::memory_order_relaxed) || pos.is_draw() || ss->ply >= MAX_PLY)
+ return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos)
+ : DrawValue[pos.side_to_move()];
// Step 3. Mate distance pruning. Even if we mate at the next move our score
// would be at best mate_in(ss->ply+1), but if alpha is already bigger because
(ss+1)->skipEarlyPruning = false; (ss+1)->reduction = DEPTH_ZERO;
(ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
- // Step 4. Transposition table lookup
- // We don't want the score of a partial search to overwrite a previous full search
- // TT value, so we use a different position key in case of an excluded move.
+ // Step 4. Transposition table lookup. We don't want the score of a partial
+ // search to overwrite a previous full search TT value, so we use a different
+ // position key in case of an excluded move.
excludedMove = ss->excludedMove;
posKey = excludedMove ? pos.exclusion_key() : pos.key();
tte = TT.probe(posKey, ttHit);
- ss->ttMove = ttMove = RootNode ? thisThread->rootMoves[thisThread->PVIdx].pv[0] : ttHit ? tte->move() : MOVE_NONE;
ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
+ ss->ttMove = ttMove = RootNode ? thisThread->rootMoves[thisThread->PVIdx].pv[0]
+ : ttHit ? tte->move() : MOVE_NONE;
- // At non-PV nodes we check for a fail high/low. We don't prune at PV nodes
+ // At non-PV nodes we check for an early TT cutoff
if ( !PvNode
&& ttHit
&& tte->depth() >= depth
- && ttValue != VALUE_NONE // Only in case of TT access race
+ && ttValue != VALUE_NONE // Possible in case of TT access race
&& (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
: (tte->bound() & BOUND_UPPER)))
{
else
{
eval = ss->staticEval =
- (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo;
+ (ss-1)->currentMove != MOVE_NULL ? evaluate(pos)
+ : -(ss-1)->staticEval + 2 * Eval::Tempo;
- tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval, TT.generation());
+ tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
+ ss->staticEval, TT.generation());
}
if (ss->skipEarlyPruning)
// Step 9. ProbCut (skipped when in check)
// If we have a very good capture (i.e. SEE > seeValues[captured_piece_type])
- // and a reduced search returns a value much above beta, we can (almost) safely
- // prune the previous move.
+ // and a reduced search returns a value much above beta, we can (almost)
+ // safely prune the previous move.
if ( !PvNode
&& depth >= 5 * ONE_PLY
&& abs(beta) < VALUE_MATE_IN_MAX_PLY)
assert((ss-1)->currentMove != MOVE_NONE);
assert((ss-1)->currentMove != MOVE_NULL);
- MovePicker mp(pos, ttMove, thisThread->History, CounterMovesHistory, PieceValue[MG][pos.captured_piece_type()]);
+ MovePicker mp(pos, ttMove, thisThread->history, PieceValue[MG][pos.captured_piece_type()]);
CheckInfo ci(pos);
while ((move = mp.next_move()) != MOVE_NONE)
moves_loop: // When in check search starts from here
- Square prevMoveSq = to_sq((ss-1)->currentMove);
- Move countermove = thisThread->Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq];
+ Square prevSq = to_sq((ss-1)->currentMove);
+ Move cm = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
+ const CounterMovesStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq];
- MovePicker mp(pos, ttMove, depth, thisThread->History, CounterMovesHistory, countermove, ss);
+ MovePicker mp(pos, ttMove, depth, thisThread->history, cmh, cm, ss);
CheckInfo ci(pos);
value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
improving = ss->staticEval >= (ss-2)->staticEval
// At root obey the "searchmoves" option and skip moves not listed in Root
// Move List. As a consequence any illegal move is also skipped. In MultiPV
// mode we also skip PV moves which have been already searched.
- if (RootNode && !std::count(thisThread->rootMoves.begin() + thisThread->PVIdx, thisThread->rootMoves.end(), move))
+ if (RootNode && !std::count(thisThread->rootMoves.begin() + thisThread->PVIdx,
+ thisThread->rootMoves.end(), move))
continue;
ss->moveCount = ++moveCount;
- if (RootNode && thisThread == Threads.main())
- {
- Signals.firstRootMove = (moveCount == 1);
-
- if (Time.elapsed() > 3000)
- sync_cout << "info depth " << depth / ONE_PLY
- << " currmove " << UCI::move(move, pos.is_chess960())
- << " currmovenumber " << moveCount + thisThread->PVIdx << sync_endl;
- }
+ if (RootNode && thisThread == Threads.main() && Time.elapsed() > 3000)
+ sync_cout << "info depth " << depth / ONE_PLY
+ << " currmove " << UCI::move(move, pos.is_chess960())
+ << " currmovenumber " << moveCount + thisThread->PVIdx << sync_endl;
if (PvNode)
(ss+1)->pv = nullptr;
&& moveCount >= FutilityMoveCounts[improving][depth])
continue;
- // History Score Pruning
- if ( depth <= 3 * ONE_PLY
- && thisThread->History[pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO
- && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
- [pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO)
+ // History based pruning
+ if ( depth <= 4 * ONE_PLY
+ && move != ss->killers[0]
+ && thisThread->history[pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO
+ && cmh[pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO)
continue;
predictedDepth = newDepth - reduction<PvNode>(improving, depth, moveCount);
{
ss->reduction = reduction<PvNode>(improving, depth, moveCount);
+ // Increase reduction for cut nodes and moves with a bad history
if ( (!PvNode && cutNode)
- || ( thisThread->History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO
- && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
- [pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
+ || ( thisThread->history[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO
+ && cmh[pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
ss->reduction += ONE_PLY;
- if ( thisThread->History[pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO
- && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
- [pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO)
+ // Decrease reduction for moves with a good history
+ if ( thisThread->history[pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO
+ && cmh[pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO)
ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY);
// Decrease reduction for moves that escape a capture
// Finished searching the move. If a stop occurred, the return value of
// the search cannot be trusted, and we return immediately without
// updating best move, PV and TT.
- if (Signals.stop)
+ if (Signals.stop.load(std::memory_order_relaxed))
return VALUE_ZERO;
if (RootNode)
{
- RootMove& rm = *std::find(thisThread->rootMoves.begin(), thisThread->rootMoves.end(), move);
+ RootMove& rm = *std::find(thisThread->rootMoves.begin(),
+ thisThread->rootMoves.end(), move);
// PV move or new best move ?
if (moveCount == 1 || value > alpha)
update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount);
// Bonus for prior countermove that caused the fail low
- else if (!bestMove)
+ else if ( depth >= 3 * ONE_PLY
+ && !bestMove
+ && !inCheck
+ && !pos.captured_piece_type()
+ && is_ok((ss - 1)->currentMove)
+ && is_ok((ss - 2)->currentMove))
{
- if (is_ok((ss - 2)->currentMove) && is_ok((ss - 1)->currentMove) && !pos.captured_piece_type() && !inCheck && depth>=3*ONE_PLY)
- {
- Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY));
- Square prevSq = to_sq((ss - 1)->currentMove);
- Square prevPrevSq = to_sq((ss - 2)->currentMove);
- HistoryStats& flMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
- flMoveCmh.updateCMH(pos.piece_on(prevSq), prevSq, bonus);
- }
+ Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1);
+ Square prevPrevSq = to_sq((ss - 2)->currentMove);
+ CounterMovesStats& prevCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
+ prevCmh.update(pos.piece_on(prevSq), prevSq, bonus);
}
tte->save(posKey, value_to_tt(bestValue, ss->ply),
// Check for an instant draw or if the maximum ply has been reached
if (pos.is_draw() || ss->ply >= MAX_PLY)
- return ss->ply >= MAX_PLY && !InCheck ? evaluate(pos) : DrawValue[pos.side_to_move()];
+ return ss->ply >= MAX_PLY && !InCheck ? evaluate(pos)
+ : DrawValue[pos.side_to_move()];
assert(0 <= ss->ply && ss->ply < MAX_PLY);
}
else
ss->staticEval = bestValue =
- (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo;
+ (ss-1)->currentMove != MOVE_NULL ? evaluate(pos)
+ : -(ss-1)->staticEval + 2 * Eval::Tempo;
// Stand pat. Return immediately if static value is at least beta
if (bestValue >= beta)
// to search the moves. Because the depth is <= 0 here, only captures,
// queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
// be generated.
- MovePicker mp(pos, ttMove, depth, pos.this_thread()->History, CounterMovesHistory, to_sq((ss-1)->currentMove));
+ MovePicker mp(pos, ttMove, depth, pos.this_thread()->history, to_sq((ss-1)->currentMove));
CheckInfo ci(pos);
// Loop through the moves until no moves remain or a beta cutoff occurs
if (PvNode) // Update pv even in fail-high case
update_pv(ss->pv, move, (ss+1)->pv);
- if (PvNode && value < beta) // Update alpha here! Always alpha < beta
+ if (PvNode && value < beta) // Update alpha here!
{
alpha = value;
bestMove = move;
}
- // update_stats() updates killers, history, countermove history and
- // countermoves stats for a quiet best move.
+ // update_stats() updates killers, history, countermove and countermove
+ // history when a new quiet best move is found.
void update_stats(const Position& pos, Stack* ss, Move move,
Depth depth, Move* quiets, int quietsCnt) {
ss->killers[0] = move;
}
- Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY));
+ Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1);
Square prevSq = to_sq((ss-1)->currentMove);
- HistoryStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq];
+ CounterMovesStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq];
Thread* thisThread = pos.this_thread();
- thisThread->History.updateH(pos.moved_piece(move), to_sq(move), bonus);
+ thisThread->history.update(pos.moved_piece(move), to_sq(move), bonus);
if (is_ok((ss-1)->currentMove))
{
- thisThread->Countermoves.update(pos.piece_on(prevSq), prevSq, move);
- cmh.updateCMH(pos.moved_piece(move), to_sq(move), bonus);
+ thisThread->counterMoves.update(pos.piece_on(prevSq), prevSq, move);
+ cmh.update(pos.moved_piece(move), to_sq(move), bonus);
}
// Decrease all the other played quiet moves
for (int i = 0; i < quietsCnt; ++i)
{
- thisThread->History.updateH(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+ thisThread->history.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
if (is_ok((ss-1)->currentMove))
- cmh.updateCMH(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+ cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
}
- // Extra penalty for PV move in previous ply when it gets refuted
- if (is_ok((ss-2)->currentMove) && (ss-1)->moveCount == 1 && !pos.captured_piece_type())
+ // Extra penalty for a quiet TT move in previous ply when it gets refuted
+ if ( (ss-1)->moveCount == 1
+ && !pos.captured_piece_type()
+ && is_ok((ss-2)->currentMove))
{
Square prevPrevSq = to_sq((ss-2)->currentMove);
- HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
- ttMoveCmh.updateCMH(pos.piece_on(prevSq), prevSq, -bonus - 2 * depth / ONE_PLY - 1);
+ CounterMovesStats& prevCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
+ prevCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY);
}
}
Move Skill::pick_best(size_t multiPV) {
- // PRNG sequence should be non-deterministic, so we seed it with the time at init
const Search::RootMoveVector& rootMoves = Threads.main()->rootMoves;
- static PRNG rng(now());
+ static PRNG rng(now()); // PRNG sequence should be non-deterministic
// RootMoves are already sorted by score in descending order
- int variance = std::min(rootMoves[0].score - rootMoves[multiPV - 1].score, PawnValueMg);
+ Value topScore = rootMoves[0].score;
+ int delta = std::min(topScore - rootMoves[multiPV - 1].score, PawnValueMg);
int weakness = 120 - 2 * level;
int maxScore = -VALUE_INFINITE;
- // Choose best move. For each move score we add two terms both dependent on
+ // Choose best move. For each move score we add two terms, both dependent on
// weakness. One deterministic and bigger for weaker levels, and one random,
// then we choose the move with the resulting highest score.
for (size_t i = 0; i < multiPV; ++i)
{
// This is our magic formula
- int push = ( weakness * int(rootMoves[0].score - rootMoves[i].score)
- + variance * (rng.rand<unsigned>() % weakness)) / 128;
+ int push = ( weakness * int(topScore - rootMoves[i].score)
+ + delta * (rng.rand<unsigned>() % weakness)) / 128;
if (rootMoves[i].score + push > maxScore)
{
best = rootMoves[i].pv[0];
}
}
+
return best;
}
+
+ // check_time() is used to print debug info and, more importantly, to detect
+ // when we are out of available time and thus stop the search.
+
+ void check_time() {
+
+ static TimePoint lastInfoTime = now();
+
+ int elapsed = Time.elapsed();
+ TimePoint tick = Limits.startTime + elapsed;
+
+ if (tick - lastInfoTime >= 1000)
+ {
+ lastInfoTime = tick;
+ dbg_print();
+ }
+
+ // An engine may not stop pondering until told so by the GUI
+ if (Limits.ponder)
+ return;
+
+ if ( (Limits.use_time_management() && elapsed > Time.maximum() - 10)
+ || (Limits.movetime && elapsed >= Limits.movetime)
+ || (Limits.nodes && Threads.nodes_searched() >= Limits.nodes))
+ Signals.stop = true;
+ }
+
} // namespace
TTEntry* tte = TT.probe(pos.key(), ttHit);
if (!ttHit || tte->move() != m) // Don't overwrite correct entries
- tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, m, VALUE_NONE, TT.generation());
+ tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE,
+ m, VALUE_NONE, TT.generation());
pos.do_move(m, *st++, pos.gives_check(m, CheckInfo(pos)));
}
}
-/// RootMove::extract_ponder_from_tt() is called in case we have no ponder move before
-/// exiting the search, for instance in case we stop the search during a fail high at
-/// root. We try hard to have a ponder move to return to the GUI, otherwise in case of
-/// 'ponder on' we have nothing to think on.
+/// RootMove::extract_ponder_from_tt() is called in case we have no ponder move
+/// before exiting the search, for instance in case we stop the search during a
+/// fail high at root. We try hard to have a ponder move to return to the GUI,
+/// otherwise in case of 'ponder on' we have nothing to think on.
bool RootMove::extract_ponder_from_tt(Position& pos)
{
return false;
}
-
-
-/// check_time() is called by the timer thread when the timer triggers. It is
-/// used to print debug info and, more importantly, to detect when we are out of
-/// available time and thus stop the search.
-
-void check_time() {
-
- static TimePoint lastInfoTime = now();
- int elapsed = Time.elapsed();
-
- if (now() - lastInfoTime >= 1000)
- {
- lastInfoTime = now();
- dbg_print();
- }
-
- // An engine may not stop pondering until told so by the GUI
- if (Limits.ponder)
- return;
-
- if (Limits.use_time_management())
- {
- bool stillAtFirstMove = Signals.firstRootMove
- && !Signals.failedLowAtRoot
- && elapsed > Time.available() * 75 / 100;
-
- if ( stillAtFirstMove
- || elapsed > Time.maximum() - 2 * TimerThread::Resolution)
- Signals.stop = true;
- }
- else if (Limits.movetime && elapsed >= Limits.movetime)
- Signals.stop = true;
-
- else if (Limits.nodes && Threads.nodes_searched() >= Limits.nodes)
- Signals.stop = true;
-}
projects / stockfish / blobdiff