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();
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());
}
}
- 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;
- 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());
+ // Wait until all threads have finished
+ for (Thread* th : Threads)
+ if (th != this)
+ th->join();
+
+ // Check if there are threads with a better score than main thread.
+ Thread* bestThread = this;
+ for (Thread* th : Threads)
+ if ( th->completedDepth > bestThread->completedDepth
+ && th->rootMoves[0].score > bestThread->rootMoves[0].score)
+ bestThread = th;
+
+ // 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)
{
{
// Set up the new depth for the helper threads
if (!isMainThread)
- rootDepth = Threads.main()->rootDepth + Depth(int(3 * log(1 + this->idx)));
+ rootDepth = std::min(DEPTH_MAX - ONE_PLY, Threads.main()->rootDepth + Depth(int(2.2 * log(1 + this->idx))));
// Age out PV variability metric
if (isMainThread)
sync_cout << UCI::pv(rootPos, rootDepth, alpha, beta) << sync_endl;
}
+ if (!Signals.stop)
+ completedDepth = rootDepth;
+
if (!isMainThread)
continue;
}
}
- searching = false;
- notify_one(); // Wake up main thread if is sleeping waiting for us
-
if (!isMainThread)
return;
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;
{
// Step 2. Check for aborted search and immediate draw
if (Signals.stop.load(std::memory_order_relaxed) || pos.is_draw() || ss->ply >= MAX_PLY)
- return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos)
+ 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
if (RootNode && thisThread == Threads.main())
{
- Signals.firstRootMove = moveCount == 1;
+ Signals.firstRootMove = (moveCount == 1);
if (Time.elapsed() > 3000)
sync_cout << "info depth " << depth / ONE_PLY
continue;
// History based pruning
- if ( depth <= 3 * ONE_PLY
+ 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;
&& is_ok((ss - 1)->currentMove)
&& is_ok((ss - 2)->currentMove))
{
- Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY));
+ 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);
}
- // 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);
CounterMovesStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq];
cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
}
- // Extra penalty for TT move in previous ply when it gets refuted
+ // 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);
CounterMovesStats& prevCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
- prevCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * depth / ONE_PLY - 1);
+ 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())
+ {
+ bool stillAtFirstMove = Signals.firstRootMove.load(std::memory_order_relaxed)
+ && !Signals.failedLowAtRoot.load(std::memory_order_relaxed)
+ && elapsed > Time.available() * 3 / 4;
+
+ if (stillAtFirstMove || elapsed > Time.maximum() - 10)
+ 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;
+ }
+
} // 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() * 3 / 4;
-
- 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