std::vector<RootMove> RootMoves;
Position RootPos;
Color RootColor;
- Time::point SearchTime;
+ Time::point SearchTime, IterationTime;
StateStackPtr SetupStates;
}
void id_loop(Position& pos);
Value value_to_tt(Value v, int ply);
Value value_from_tt(Value v, int ply);
+ void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt);
string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
struct Skill {
sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
}
+ IterationTime = Time::now() - SearchTime;
+
// If skill levels are enabled and time is up, pick a sub-optimal best move
if (skill.enabled() && skill.time_to_pick(depth))
skill.pick_move();
if (depth > 4 && depth < 50 && PVSize == 1)
TimeMgr.pv_instability(BestMoveChanges);
- // Stop the search if most of the available time has been used. We
- // probably don't have enough time to search the first move at the
- // next iteration anyway.
- if (Time::now() - SearchTime > (TimeMgr.available_time() * 62) / 100)
+ // Stop the search if only one legal move is available or most
+ // of the available time has been used. We probably don't have
+ // enough time to search the first move at the next iteration anyway.
+ if ( RootMoves.size() == 1
+ || IterationTime > (TimeMgr.available_time() * 62) / 100)
stop = true;
- // Stop the search early if one move seems to be much better than others
- if ( depth >= 12
- && BestMoveChanges <= DBL_EPSILON
- && !stop
- && PVSize == 1
- && bestValue > VALUE_MATED_IN_MAX_PLY
- && ( RootMoves.size() == 1
- || Time::now() - SearchTime > (TimeMgr.available_time() * 20) / 100))
- {
- Value rBeta = bestValue - 2 * PawnValueMg;
- ss->excludedMove = RootMoves[0].pv[0];
- ss->skipNullMove = true;
- Value v = search<NonPV>(pos, ss, rBeta - 1, rBeta, (depth - 3) * ONE_PLY, true);
- ss->skipNullMove = false;
- ss->excludedMove = MOVE_NONE;
-
- if (v < rBeta)
- stop = true;
- }
-
if (stop)
{
// If we are allowed to ponder do not stop the search now but
TT.refresh(tte);
ss->currentMove = ttMove; // Can be MOVE_NONE
- // Update killers, history, and counter move on TT hit
- if ( ttValue >= beta
- && ttMove
- && !pos.capture_or_promotion(ttMove)
- && !inCheck)
- {
- if (ss->killers[0] != ttMove)
- {
- ss->killers[1] = ss->killers[0];
- ss->killers[0] = ttMove;
- }
-
- Value bonus = Value(int(depth) * int(depth));
- History.update(pos.moved_piece(ttMove), to_sq(ttMove), bonus);
+ // If ttMove is quiet, update killers, history, and counter move on TT hit
+ if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove) && !inCheck)
+ update_stats(pos, ss, ttMove, depth, NULL, 0);
- if (is_ok((ss-1)->currentMove))
- {
- Square prevMoveSq = to_sq((ss-1)->currentMove);
- Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, ttMove);
- }
- }
return ttValue;
}
depth, bestMove, ss->staticEval);
// Quiet best move: update killers, history and countermoves
- if ( bestValue >= beta
- && !pos.capture_or_promotion(bestMove)
- && !inCheck)
- {
- if (ss->killers[0] != bestMove)
- {
- ss->killers[1] = ss->killers[0];
- ss->killers[0] = bestMove;
- }
-
- // Increase history value of the cut-off move and decrease all the other
- // played non-capture moves.
- Value bonus = Value(int(depth) * int(depth));
- History.update(pos.moved_piece(bestMove), to_sq(bestMove), bonus);
- for (int i = 0; i < quietCount - 1; ++i)
- {
- Move m = quietsSearched[i];
- History.update(pos.moved_piece(m), to_sq(m), -bonus);
- }
-
- if (is_ok((ss-1)->currentMove))
- Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, bestMove);
- }
+ if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck)
+ update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
}
+ // update_stats() updates killers, history and countermoves stats after a fail-high
+ // of a quiet move.
+
+ void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) {
+
+ if (ss->killers[0] != move)
+ {
+ ss->killers[1] = ss->killers[0];
+ ss->killers[0] = move;
+ }
+
+ // Increase history value of the cut-off move and decrease all the other
+ // played quiet moves.
+ Value bonus = Value(int(depth) * int(depth));
+ History.update(pos.moved_piece(move), to_sq(move), bonus);
+ for (int i = 0; i < quietsCnt; ++i)
+ {
+ Move m = quiets[i];
+ History.update(pos.moved_piece(m), to_sq(m), -bonus);
+ }
+
+ if (is_ok((ss-1)->currentMove))
+ {
+ Square prevMoveSq = to_sq((ss-1)->currentMove);
+ Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, move);
+ }
+ }
+
+
// When playing with a strength handicap, choose best move among the MultiPV
// set using a statistical rule dependent on 'level'. Idea by Heinz van Saanen.
Time::point elapsed = Time::now() - SearchTime;
bool stillAtFirstMove = Signals.firstRootMove
&& !Signals.failedLowAtRoot
- && elapsed > TimeMgr.available_time();
+ && elapsed > (TimeMgr.available_time() * 62) / 100
+ && elapsed > IterationTime * 1.4;
bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution
|| stillAtFirstMove;
projects / stockfish / blobdiff