SignalsType Signals;
LimitsType Limits;
- StateStackPtr SetupStates;
}
namespace Tablebases {
Move pv[3];
};
+ // Set of rows with half bits set to 1 and half to 0. It is used to allocate
+ // the search depths across the threads.
+ typedef std::vector<int> Row;
+
+ const Row HalfDensity[] = {
+ {0, 1},
+ {1, 0},
+ {0, 0, 1, 1},
+ {0, 1, 1, 0},
+ {1, 1, 0, 0},
+ {1, 0, 0, 1},
+ {0, 0, 0, 1, 1, 1},
+ {0, 0, 1, 1, 1, 0},
+ {0, 1, 1, 1, 0, 0},
+ {1, 1, 1, 0, 0, 0},
+ {1, 1, 0, 0, 0, 1},
+ {1, 0, 0, 0, 1, 1},
+ {0, 0, 0, 0, 1, 1, 1, 1},
+ {0, 0, 0, 1, 1, 1, 1, 0},
+ {0, 0, 1, 1, 1, 1, 0 ,0},
+ {0, 1, 1, 1, 1, 0, 0 ,0},
+ {1, 1, 1, 1, 0, 0, 0 ,0},
+ {1, 1, 1, 0, 0, 0, 0 ,1},
+ {1, 1, 0, 0, 0, 0, 1 ,1},
+ {1, 0, 0, 0, 0, 1, 1 ,1},
+ };
+
+ const size_t HalfDensitySize = std::extent<decltype(HalfDensity)>::value;
+
EasyMoveManager EasyMove;
Value DrawValue[COLOR_NB];
CounterMoveHistoryStats CounterMoveHistory;
void Search::init() {
- const double K[][2] = {{ 0.799, 2.281 }, { 0.484, 3.023 }};
-
- for (int pv = 0; pv <= 1; ++pv)
- for (int imp = 0; imp <= 1; ++imp)
- for (int d = 1; d < 64; ++d)
- for (int mc = 1; mc < 64; ++mc)
- {
- double r = K[pv][0] + log(d) * log(mc) / K[pv][1];
+ for (int imp = 0; imp <= 1; ++imp)
+ for (int d = 1; d < 64; ++d)
+ for (int mc = 1; mc < 64; ++mc)
+ {
+ double r = log(d) * log(mc) / 2;
+ if (r < 0.80)
+ continue;
- if (r >= 1.5)
- Reductions[pv][imp][d][mc] = int(r) * ONE_PLY;
+ Reductions[NonPV][imp][d][mc] = int(std::round(r)) * ONE_PLY;
+ Reductions[PV][imp][d][mc] = std::max(Reductions[NonPV][imp][d][mc] - ONE_PLY, DEPTH_ZERO);
- // Increase reduction when eval is not improving
- if (!pv && !imp && Reductions[pv][imp][d][mc] >= 2 * ONE_PLY)
- Reductions[pv][imp][d][mc] += ONE_PLY;
- }
+ // Increase reduction for non-PV nodes when eval is not improving
+ if (!imp && Reductions[NonPV][imp][d][mc] >= 2 * ONE_PLY)
+ Reductions[NonPV][imp][d][mc] += ONE_PLY;
+ }
for (int d = 0; d < 16; ++d)
{
}
else
{
- if (TB::Cardinality >= rootPos.count<ALL_PIECES>(WHITE)
- + rootPos.count<ALL_PIECES>(BLACK))
+ if ( TB::Cardinality >= rootPos.count<ALL_PIECES>(WHITE)
+ + rootPos.count<ALL_PIECES>(BLACK)
+ && !rootPos.can_castle(ANY_CASTLING))
{
// If the current root position is in the tablebases, then RootMoves
// contains only moves that preserve the draw or the win.
}
for (Thread* th : Threads)
- {
- th->maxPly = 0;
- th->rootDepth = DEPTH_ZERO;
if (th != this)
- {
- th->rootPos = Position(rootPos, th);
- th->rootMoves = rootMoves;
th->start_searching();
- }
- }
Thread::search(); // Let's start searching!
}
Thread* bestThread = this;
if ( !this->easyMovePlayed
&& Options["MultiPV"] == 1
- && !Skill(Options["Skill Level"]).enabled())
+ && !Skill(Options["Skill Level"]).enabled()
+ && rootMoves[0].pv[0] != MOVE_NONE)
{
for (Thread* th : Threads)
if ( th->completedDepth > bestThread->completedDepth
void Thread::search() {
- Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
+ Stack stack[MAX_PLY+7], *ss = stack+5; // To allow referencing (ss-5) and (ss+2)
Value bestValue, alpha, beta, delta;
Move easyMove = MOVE_NONE;
MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
- std::memset(ss-2, 0, 5 * sizeof(Stack));
+ std::memset(ss-5, 0, 8 * sizeof(Stack));
bestValue = delta = alpha = -VALUE_INFINITE;
beta = VALUE_INFINITE;
while (++rootDepth < DEPTH_MAX && !Signals.stop && (!Limits.depth || rootDepth <= Limits.depth))
{
// Set up the new depths for the helper threads skipping on average every
- // 2nd ply (using a half-density map similar to a Hadamard matrix).
+ // 2nd ply (using a half-density matrix).
if (!mainThread)
{
- 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;
- }
+ const Row& row = HalfDensity[(idx - 1) % HalfDensitySize];
+ if (row[(rootDepth + rootPos.game_ply()) % row.size()])
+ continue;
}
// Age out PV variability metric
{
if (!Signals.stop && !Signals.stopOnPonderhit)
{
- // Take some extra time if the best move has changed
- if (rootDepth > 4 * ONE_PLY && multiPV == 1)
- Time.pv_instability(mainThread->bestMoveChanges);
-
// Stop the search if only one legal move is available, or if all
// of the available time has been used, or if we matched an easyMove
// from the previous search and just did a fast verification.
bestValue >= mainThread->previousScore };
int improvingFactor = 640 - 160*F[0] - 126*F[1] - 124*F[0]*F[1];
+ double unstablePvFactor = 1 + mainThread->bestMoveChanges;
bool doEasyMove = rootMoves[0].pv[0] == easyMove
&& mainThread->bestMoveChanges < 0.03
- && Time.elapsed() > Time.available() * 25 / 206;
+ && Time.elapsed() > Time.optimum() * 25 / 204;
if ( rootMoves.size() == 1
- || Time.elapsed() > Time.available() * improvingFactor / 640
+ || Time.elapsed() > Time.optimum() * unstablePvFactor * improvingFactor / 634
|| (mainThread->easyMovePlayed = doEasyMove))
{
// If we are allowed to ponder do not stop the search now but
assert(0 <= ss->ply && ss->ply < MAX_PLY);
ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
+ ss->counterMoves = nullptr;
(ss+1)->skipEarlyPruning = false;
(ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
if ( piecesCnt <= TB::Cardinality
&& (piecesCnt < TB::Cardinality || depth >= TB::ProbeDepth)
- && pos.rule50_count() == 0)
+ && pos.rule50_count() == 0
+ && !pos.can_castle(ANY_CASTLING))
{
int found, v = Tablebases::probe_wdl(pos, &found);
&& pos.non_pawn_material(pos.side_to_move()))
{
ss->currentMove = MOVE_NULL;
+ ss->counterMoves = nullptr;
assert(eval - beta >= 0);
assert((ss-1)->currentMove != MOVE_NONE);
assert((ss-1)->currentMove != MOVE_NULL);
- MovePicker mp(pos, ttMove, thisThread->history, PieceValue[MG][pos.captured_piece_type()]);
+ MovePicker mp(pos, ttMove, PieceValue[MG][pos.captured_piece_type()]);
CheckInfo ci(pos);
while ((move = mp.next_move()) != MOVE_NONE)
if (pos.legal(move, ci.pinned))
{
ss->currentMove = move;
+ ss->counterMoves = &CounterMoveHistory[pos.moved_piece(move)][to_sq(move)];
pos.do_move(move, st, pos.gives_check(move, ci));
value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode);
pos.undo_move(move);
moves_loop: // When in check search starts from here
Square prevSq = to_sq((ss-1)->currentMove);
- Move cm = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
const CounterMoveStats& cmh = CounterMoveHistory[pos.piece_on(prevSq)][prevSq];
- MovePicker mp(pos, ttMove, depth, thisThread->history, cmh, cm, ss);
+ MovePicker mp(pos, ttMove, depth, ss);
CheckInfo ci(pos);
value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
improving = ss->staticEval >= (ss-2)->staticEval
&& cmh[pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO)
continue;
- predictedDepth = newDepth - reduction<PvNode>(improving, depth, moveCount);
+ predictedDepth = std::max(newDepth - reduction<PvNode>(improving, depth, moveCount), DEPTH_ZERO);
// Futility pruning: parent node
if (predictedDepth < 7 * ONE_PLY)
}
ss->currentMove = move;
+ ss->counterMoves = &CounterMoveHistory[pos.moved_piece(move)][to_sq(move)];
// Step 14. Make the move
pos.do_move(move, st, givesCheck);
&& !captureOrPromotion)
{
Depth r = reduction<PvNode>(improving, depth, moveCount);
+ Value hValue = thisThread->history[pos.piece_on(to_sq(move))][to_sq(move)];
+ Value cmhValue = cmh[pos.piece_on(to_sq(move))][to_sq(move)];
// 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
- && cmh[pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
+ || (hValue < VALUE_ZERO && cmhValue <= VALUE_ZERO))
r += ONE_PLY;
// Decrease/increase reduction for moves with a good/bad history
- int rHist = ( thisThread->history[pos.piece_on(to_sq(move))][to_sq(move)]
- + cmh[pos.piece_on(to_sq(move))][to_sq(move)]) / 14980;
+ int rHist = (hValue + cmhValue) / 14980;
r = std::max(DEPTH_ZERO, r - rHist * ONE_PLY);
// Decrease reduction for moves that escape a capture. Filter out
&& !bestMove
&& !inCheck
&& !pos.captured_piece_type()
- && is_ok((ss - 1)->currentMove)
- && is_ok((ss - 2)->currentMove))
+ && is_ok((ss-1)->currentMove))
{
Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1);
- Square prevPrevSq = to_sq((ss - 2)->currentMove);
- CounterMoveStats& prevCmh = CounterMoveHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
- prevCmh.update(pos.piece_on(prevSq), prevSq, bonus);
+ if ((ss-2)->counterMoves)
+ (ss-2)->counterMoves->update(pos.piece_on(prevSq), prevSq, bonus);
+
+ if ((ss-3)->counterMoves)
+ (ss-3)->counterMoves->update(pos.piece_on(prevSq), prevSq, bonus);
+
+ if ((ss-5)->counterMoves)
+ (ss-5)->counterMoves->update(pos.piece_on(prevSq), prevSq, bonus);
}
tte->save(posKey, value_to_tt(bestValue, ss->ply),
// 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, to_sq((ss-1)->currentMove));
+ MovePicker mp(pos, ttMove, depth, to_sq((ss-1)->currentMove));
CheckInfo ci(pos);
// Loop through the moves until no moves remain or a beta cutoff occurs
}
- // update_stats() updates killers, history, countermove and countermove
- // history when a new quiet best move is found.
+ // update_stats() updates killers, history, countermove and countermove plus
+ // follow-up move 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) {
Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1);
Square prevSq = to_sq((ss-1)->currentMove);
- CounterMoveStats& cmh = CounterMoveHistory[pos.piece_on(prevSq)][prevSq];
+ CounterMoveStats* cmh = (ss-1)->counterMoves;
+ CounterMoveStats* fmh = (ss-2)->counterMoves;
+ CounterMoveStats* fmh2 = (ss-4)->counterMoves;
Thread* thisThread = pos.this_thread();
thisThread->history.update(pos.moved_piece(move), to_sq(move), bonus);
- if (is_ok((ss-1)->currentMove))
+ if (cmh)
{
thisThread->counterMoves.update(pos.piece_on(prevSq), prevSq, move);
- cmh.update(pos.moved_piece(move), to_sq(move), bonus);
+ cmh->update(pos.moved_piece(move), to_sq(move), bonus);
}
+ if (fmh)
+ fmh->update(pos.moved_piece(move), to_sq(move), bonus);
+
+ if (fmh2)
+ fmh2->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.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
- if (is_ok((ss-1)->currentMove))
- cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+ if (cmh)
+ cmh->update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+
+ if (fmh)
+ fmh->update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
+
+ if (fmh2)
+ fmh2->update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
}
// 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))
+ if ((ss-1)->moveCount == 1 && !pos.captured_piece_type())
{
- Square prevPrevSq = to_sq((ss-2)->currentMove);
- CounterMoveStats& prevCmh = CounterMoveHistory[pos.piece_on(prevPrevSq)][prevPrevSq];
- prevCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY);
+ if ((ss-2)->counterMoves)
+ (ss-2)->counterMoves->update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY);
+
+ if ((ss-3)->counterMoves)
+ (ss-3)->counterMoves->update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY);
+
+ if ((ss-5)->counterMoves)
+ (ss-5)->counterMoves->update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY);
}
}
Move Skill::pick_best(size_t multiPV) {
- const Search::RootMoveVector& rootMoves = Threads.main()->rootMoves;
+ const RootMoves& rootMoves = Threads.main()->rootMoves;
static PRNG rng(now()); // PRNG sequence should be non-deterministic
// RootMoves are already sorted by score in descending order
std::stringstream ss;
int elapsed = Time.elapsed() + 1;
- const Search::RootMoveVector& rootMoves = pos.this_thread()->rootMoves;
+ const RootMoves& rootMoves = pos.this_thread()->rootMoves;
size_t PVIdx = pos.this_thread()->PVIdx;
size_t multiPV = std::min((size_t)Options["MultiPV"], rootMoves.size());
uint64_t nodes_searched = Threads.nodes_searched();
projects / stockfish / blobdiff