#include "evaluate.h"
#include "movegen.h"
#include "movepick.h"
-#include "notation.h"
#include "rkiss.h"
#include "search.h"
#include "timeman.h"
#include "thread.h"
#include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
namespace Search {
inline Value razor_margin(Depth d) { return Value(512 + 32 * d); }
// Futility lookup tables (initialized at startup) and their access functions
- int FutilityMoveCounts[2][32]; // [improving][depth]
+ int FutilityMoveCounts[2][16]; // [improving][depth]
inline Value futility_margin(Depth d) {
return Value(200 * d);
Value value_to_tt(Value v, int ply);
Value value_from_tt(Value v, int ply);
void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt);
- string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
+ string uci_pv(const Position& pos, Depth depth, Value alpha, Value beta);
struct Skill {
Skill(int l, size_t rootSize) : level(l),
}
size_t candidates_size() const { return candidates; }
- bool time_to_pick(int depth) const { return depth == 1 + level; }
+ bool time_to_pick(Depth depth) const { return depth == 1 + level; }
Move pick_move();
int level;
void Search::init() {
- int d; // depth (ONE_PLY == 2)
- int hd; // half depth (ONE_PLY == 1)
- int mc; // moveCount
-
// Init reductions array
- for (hd = 1; hd < 64; ++hd) for (mc = 1; mc < 64; ++mc)
- {
- double pvRed = 0.00 + log(double(hd)) * log(double(mc)) / 3.00;
- double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25;
+ for (int d = 1; d < 64; ++d)
+ for (int mc = 1; mc < 64; ++mc)
+ {
+ double pvRed = 0.00 + log(double(d)) * log(double(mc)) / 3.00;
+ double nonPVRed = 0.33 + log(double(d)) * log(double(mc)) / 2.25;
- Reductions[1][1][hd][mc] = int8_t( pvRed >= 1.0 ? pvRed + 0.5: 0);
- Reductions[0][1][hd][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed + 0.5: 0);
+ Reductions[1][1][d][mc] = int8_t( pvRed >= 1.0 ? pvRed + 0.5: 0);
+ Reductions[0][1][d][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed + 0.5: 0);
- Reductions[1][0][hd][mc] = Reductions[1][1][hd][mc];
- Reductions[0][0][hd][mc] = Reductions[0][1][hd][mc];
+ Reductions[1][0][d][mc] = Reductions[1][1][d][mc];
+ Reductions[0][0][d][mc] = Reductions[0][1][d][mc];
- if (Reductions[0][0][hd][mc] >= 2)
- Reductions[0][0][hd][mc] += 1;
- }
+ // Increase reduction when eval is not improving
+ if (Reductions[0][0][d][mc] >= 2)
+ Reductions[0][0][d][mc] += 1;
+ }
// Init futility move count array
- for (d = 0; d < 32; ++d)
+ for (int d = 0; d < 16; ++d)
{
- FutilityMoveCounts[0][d] = int(2.4 + 0.222 * pow(d * 2 + 0.00, 1.8));
- FutilityMoveCounts[1][d] = int(3.0 + 0.300 * pow(d * 2 + 0.98, 1.8));
+ FutilityMoveCounts[0][d] = int(2.4 + 0.773 * pow(d + 0.00, 1.8));
+ FutilityMoveCounts[1][d] = int(2.9 + 1.045 * pow(d + 0.49, 1.8));
}
}
pos.undo_move(*it);
}
if (Root)
- sync_cout << move_to_uci(*it, pos.is_chess960()) << ": " << cnt << sync_endl;
+ sync_cout << UCI::format_move(*it, pos.is_chess960()) << ": " << cnt << sync_endl;
}
return nodes;
}
{
RootMoves.push_back(MOVE_NONE);
sync_cout << "info depth 0 score "
- << score_to_uci(RootPos.checkers() ? -VALUE_MATE : VALUE_DRAW)
+ << UCI::format_value(RootPos.checkers() ? -VALUE_MATE : VALUE_DRAW)
<< sync_endl;
-
- goto finalize;
}
+ else
+ {
+ for (size_t i = 0; i < Threads.size(); ++i)
+ Threads[i]->maxPly = 0;
- // Reset the threads, still sleeping: will wake up at split time
- for (size_t i = 0; i < Threads.size(); ++i)
- Threads[i]->maxPly = 0;
-
- Threads.timer->run = true;
- Threads.timer->notify_one(); // Wake up the recurring timer
-
- id_loop(RootPos); // Let's start searching !
-
- Threads.timer->run = false; // Stop the timer
+ Threads.timer->run = true;
+ Threads.timer->notify_one(); // Wake up the recurring timer
-finalize:
+ id_loop(RootPos); // Let's start searching !
- // When search is stopped this info is not printed
- sync_cout << "info nodes " << RootPos.nodes_searched()
- << " time " << Time::now() - SearchTime + 1 << sync_endl;
+ Threads.timer->run = false;
+ }
// When we reach the maximum depth, we can arrive here without a raise of
// Signals.stop. However, if we are pondering or in an infinite search,
RootPos.this_thread()->wait_for(Signals.stop);
}
- // Best move could be MOVE_NONE when searching on a stalemate position
- sync_cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], RootPos.is_chess960())
- << " ponder " << move_to_uci(RootMoves[0].pv[1], RootPos.is_chess960())
+ sync_cout << "bestmove " << UCI::format_move(RootMoves[0].pv[0], RootPos.is_chess960())
+ << " ponder " << UCI::format_move(RootMoves[0].pv[1], RootPos.is_chess960())
<< sync_endl;
}
void id_loop(Position& pos) {
- Stack stack[MAX_PLY_PLUS_6], *ss = stack+2; // To allow referencing (ss-2)
- int depth;
+ Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
+ Depth depth;
Value bestValue, alpha, beta, delta;
std::memset(ss-2, 0, 5 * sizeof(Stack));
- depth = 0;
+ depth = DEPTH_ZERO;
BestMoveChanges = 0;
bestValue = delta = alpha = -VALUE_INFINITE;
beta = VALUE_INFINITE;
multiPV = std::max(multiPV, skill.candidates_size());
// Iterative deepening loop until requested to stop or target depth reached
- while (++depth <= MAX_PLY && !Signals.stop && (!Limits.depth || depth <= Limits.depth))
+ while (++depth < MAX_PLY && !Signals.stop && (!Limits.depth || depth <= Limits.depth))
{
// Age out PV variability metric
BestMoveChanges *= 0.5;
for (PVIdx = 0; PVIdx < std::min(multiPV, RootMoves.size()) && !Signals.stop; ++PVIdx)
{
// Reset aspiration window starting size
- if (depth >= 5)
+ if (depth >= 5 * ONE_PLY)
{
delta = Value(16);
alpha = std::max(RootMoves[PVIdx].prevScore - delta,-VALUE_INFINITE);
// high/low anymore.
while (true)
{
- bestValue = search<Root, false>(pos, ss, alpha, beta, depth * ONE_PLY, false);
+ bestValue = search<Root, false>(pos, ss, alpha, beta, depth, 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
// re-search, otherwise exit the loop.
if (bestValue <= alpha)
{
+ beta = (alpha + beta) / 2;
alpha = std::max(bestValue - delta, -VALUE_INFINITE);
Signals.failedLowAtRoot = true;
Signals.stopOnPonderhit = false;
}
else if (bestValue >= beta)
+ {
+ alpha = (alpha + beta) / 2;
beta = std::min(bestValue + delta, VALUE_INFINITE);
-
+ }
else
break;
- delta += 3 * delta / 8;
+ delta += delta / 2;
assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
}
// Sort the PV lines searched so far and update the GUI
std::stable_sort(RootMoves.begin(), RootMoves.begin() + PVIdx + 1);
- if (PVIdx + 1 == std::min(multiPV, RootMoves.size()) || Time::now() - SearchTime > 3000)
+ if (Signals.stop)
+ sync_cout << "info nodes " << RootPos.nodes_searched()
+ << " time " << Time::now() - SearchTime << sync_endl;
+
+ else if ( PVIdx + 1 == std::min(multiPV, RootMoves.size())
+ || Time::now() - SearchTime > 3000)
sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
}
if (Limits.use_time_management() && !Signals.stop && !Signals.stopOnPonderhit)
{
// Take some extra time if the best move has changed
- if (depth > 4 && multiPV == 1)
+ if (depth > 4 * ONE_PLY && multiPV == 1)
TimeMgr.pv_instability(BestMoveChanges);
// Stop the search if only one legal move is available or all
assert(PvNode || (alpha == beta - 1));
assert(depth > DEPTH_ZERO);
+ PVEntry pv;
Move quietsSearched[64];
StateInfo st;
const TTEntry *tte;
Move ttMove, move, excludedMove, bestMove;
Depth ext, newDepth, predictedDepth;
Value bestValue, value, ttValue, eval, nullValue, futilityValue;
- bool inCheck, givesCheck, pvMove, singularExtensionNode, improving;
+ bool inCheck, givesCheck, singularExtensionNode, improving;
bool captureOrPromotion, dangerous, doFullDepthSearch;
int moveCount, quietCount;
moveCount = quietCount = 0;
bestValue = -VALUE_INFINITE;
- ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
ss->ply = (ss-1)->ply + 1;
- (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
- (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
// Used to send selDepth info to GUI
if (PvNode && 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 || 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
return alpha;
}
+ assert(0 <= ss->ply && ss->ply < MAX_PLY);
+
+ ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
+ (ss+1)->skipNullMove = 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.
// a fail high/low. The biggest advantage to probing at PV nodes is to have a
// smooth experience in analysis mode. We don't probe at Root nodes otherwise
// we should also update RootMoveList to avoid bogus output.
- if ( !RootNode
+ if ( !PvNode
&& tte
&& tte->depth() >= depth
&& ttValue != VALUE_NONE // Only in case of TT access race
- && ( PvNode ? tte->bound() == BOUND_EXACT
- : ttValue >= beta ? (tte->bound() & BOUND_LOWER)
- : (tte->bound() & BOUND_UPPER)))
+ && (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
+ : (tte->bound() & BOUND_UPPER)))
{
ss->currentMove = ttMove; // Can be MOVE_NONE
if (thisThread == Threads.main() && Time::now() - SearchTime > 3000)
sync_cout << "info depth " << depth
- << " currmove " << move_to_uci(move, pos.is_chess960())
+ << " currmove " << UCI::format_move(move, pos.is_chess960())
<< " currmovenumber " << moveCount + PVIdx << sync_endl;
}
+ if (PvNode)
+ (ss+1)->pv = NULL;
+
ext = DEPTH_ZERO;
captureOrPromotion = pos.capture_or_promotion(move);
&& !captureOrPromotion
&& !inCheck
&& !dangerous
- /* && move != ttMove Already implicit in the next condition */
&& bestValue > VALUE_MATED_IN_MAX_PLY)
{
// Move count based pruning
continue;
}
- pvMove = PvNode && moveCount == 1;
ss->currentMove = move;
if (!SpNode && !captureOrPromotion && quietCount < 64)
quietsSearched[quietCount++] = move;
// Step 15. Reduced depth search (LMR). If the move fails high it will be
// re-searched at full depth.
if ( depth >= 3 * ONE_PLY
- && !pvMove
+ && moveCount > 1
&& !captureOrPromotion
- && move != ttMove
&& move != ss->killers[0]
&& move != ss->killers[1])
{
ss->reduction = DEPTH_ZERO;
}
else
- doFullDepthSearch = !pvMove;
+ doFullDepthSearch = !PvNode || moveCount > 1;
// Step 16. Full depth search, when LMR is skipped or fails high
if (doFullDepthSearch)
// For PV nodes only, do a full PV search on the first move or after a fail
// high (in the latter case search only if value < beta), otherwise let the
// parent node fail low with value <= alpha and to try another move.
- if (PvNode && (pvMove || (value > alpha && (RootNode || value < beta))))
+ if (PvNode && (moveCount == 1 || (value > alpha && (RootNode || value < beta)))) {
+ pv.pv[0] = MOVE_NONE;
+ (ss+1)->pv = &pv;
value = newDepth < ONE_PLY ?
givesCheck ? -qsearch<PV, true>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: -qsearch<PV, false>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: - search<PV, false>(pos, ss+1, -beta, -alpha, newDepth, false);
+ }
// Step 17. Undo move
pos.undo_move(move);
RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), move);
// PV move or new best move ?
- if (pvMove || value > alpha)
+ if (moveCount == 1 || value > alpha)
{
rm.score = value;
- rm.extract_pv_from_tt(pos);
+ rm.pv.resize(1);
+ for (int i = 0; (ss+1)->pv && i < MAX_PLY && (ss+1)->pv->pv[i] != MOVE_NONE; ++i)
+ rm.pv.push_back((ss+1)->pv->pv[i]);
// We record how often the best move has been changed in each
// iteration. This information is used for time management: When
// the best move changes frequently, we allocate some more time.
- if (!pvMove)
+ if (moveCount > 1)
++BestMoveChanges;
}
else
{
bestMove = SpNode ? splitPoint->bestMove = move : move;
+ if (NT == PV) {
+ ss->pv->update(move, (ss+1)->pv);
+ if (SpNode)
+ splitPoint->ss->pv->update(move, (ss+1)->pv);
+ }
+
if (PvNode && value < beta) // Update alpha! Always alpha < beta
alpha = SpNode ? splitPoint->alpha = value : value;
else
assert(PvNode || (alpha == beta - 1));
assert(depth <= DEPTH_ZERO);
+ PVEntry pv;
StateInfo st;
const TTEntry* tte;
Key posKey;
bool givesCheck, evasionPrunable;
Depth ttDepth;
- // To flag BOUND_EXACT a node with eval above alpha and no available moves
- if (PvNode)
+ if (PvNode) {
+ // To flag BOUND_EXACT a node with eval above alpha and no available moves
oldAlpha = alpha;
+ (ss+1)->pv = &pv;
+ ss->pv->pv[0] = MOVE_NONE;
+ }
+
ss->currentMove = bestMove = MOVE_NONE;
ss->ply = (ss-1)->ply + 1;
// 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()];
+ if (pos.is_draw() || ss->ply >= MAX_PLY)
+ return ss->ply >= MAX_PLY && !InCheck ? evaluate(pos) : DrawValue[pos.side_to_move()];
+
+ assert(0 <= ss->ply && ss->ply < MAX_PLY);
// Decide whether or not to include checks: this fixes also the type of
// TT entry depth that we are going to use. Note that in qsearch we use
ttMove = tte ? tte->move() : MOVE_NONE;
ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_NONE;
- if ( tte
+ if ( !PvNode
+ && tte
&& tte->depth() >= ttDepth
&& ttValue != VALUE_NONE // Only in case of TT access race
- && ( PvNode ? tte->bound() == BOUND_EXACT
- : ttValue >= beta ? (tte->bound() & BOUND_LOWER)
- : (tte->bound() & BOUND_UPPER)))
+ && (ttValue >= beta ? (tte->bound() & BOUND_LOWER)
+ : (tte->bound() & BOUND_UPPER)))
{
ss->currentMove = ttMove; // Can be MOVE_NONE
return ttValue;
if ( !PvNode
&& !InCheck
&& !givesCheck
- && move != ttMove
&& futilityBase > -VALUE_KNOWN_WIN
&& !pos.advanced_pawn_push(move))
{
// Don't search moves with negative SEE values
if ( !PvNode
&& (!InCheck || evasionPrunable)
- && move != ttMove
&& type_of(move) != PROMOTION
&& pos.see_sign(move) < VALUE_ZERO)
continue;
if (value > alpha)
{
+ if (PvNode)
+ ss->pv->update(move, &pv);
+
if (PvNode && value < beta) // Update alpha here! Always alpha < beta
{
alpha = value;
// requires that all (if any) unsearched PV lines are sent using a previous
// search score.
- string uci_pv(const Position& pos, int depth, Value alpha, Value beta) {
+ string uci_pv(const Position& pos, Depth depth, Value alpha, Value beta) {
std::stringstream ss;
Time::point elapsed = Time::now() - SearchTime + 1;
if (depth == 1 && !updated)
continue;
- int d = updated ? depth : depth - 1;
+ Depth d = updated ? depth : depth - ONE_PLY;
Value v = updated ? RootMoves[i].score : RootMoves[i].prevScore;
if (ss.rdbuf()->in_avail()) // Not at first line
ss << "\n";
- ss << "info depth " << d
+ ss << "info depth " << d / ONE_PLY
<< " seldepth " << selDepth
- << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
+ << " multipv " << i + 1
+ << " score " << (i == PVIdx ? UCI::format_value(v, alpha, beta) : UCI::format_value(v))
<< " nodes " << pos.nodes_searched()
<< " nps " << pos.nodes_searched() * 1000 / elapsed
<< " time " << elapsed
- << " multipv " << i + 1
<< " pv";
- for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; ++j)
- ss << " " << move_to_uci(RootMoves[i].pv[j], pos.is_chess960());
+ for (size_t j = 0; j < RootMoves[i].pv.size(); ++j)
+ ss << " " << UCI::format_move(RootMoves[i].pv[j], pos.is_chess960());
}
return ss.str();
} // namespace
-/// RootMove::extract_pv_from_tt() builds a PV by adding moves from the TT table.
-/// We also consider both failing high nodes and BOUND_EXACT nodes here to
-/// ensure that we have a ponder move even when we fail high at root. This
-/// results in a long PV to print that is important for position analysis.
-
-void RootMove::extract_pv_from_tt(Position& pos) {
-
- StateInfo state[MAX_PLY_PLUS_6], *st = state;
- const TTEntry* tte;
- int ply = 1; // At root ply is 1...
- Move m = pv[0]; // ...instead pv[] array starts from 0
- Value expectedScore = score;
-
- pv.clear();
-
- do {
- pv.push_back(m);
-
- assert(MoveList<LEGAL>(pos).contains(pv[ply - 1]));
-
- pos.do_move(pv[ply++ - 1], *st++);
- tte = TT.probe(pos.key());
- expectedScore = -expectedScore;
-
- } while ( tte
- && expectedScore == value_from_tt(tte->value(), ply)
- && pos.pseudo_legal(m = tte->move()) // Local copy, TT could change
- && pos.legal(m, pos.pinned_pieces(pos.side_to_move()))
- && ply < MAX_PLY
- && (!pos.is_draw() || ply <= 2));
-
- pv.push_back(MOVE_NONE); // Must be zero-terminating
-
- while (--ply) pos.undo_move(pv[ply - 1]);
-}
-
-
/// RootMove::insert_pv_in_tt() is called at the end of a search iteration, and
/// inserts the PV back into the TT. This makes sure the old PV moves are searched
/// first, even if the old TT entries have been overwritten.
void RootMove::insert_pv_in_tt(Position& pos) {
- StateInfo state[MAX_PLY_PLUS_6], *st = state;
+ StateInfo state[MAX_PLY], *st = state;
const TTEntry* tte;
- int idx = 0; // Ply starts from 1, we need to start from 0
+ int idx = 0;
- do {
+ for (; idx < int(pv.size()); ++idx) {
tte = TT.probe(pos.key());
if (!tte || tte->move() != pv[idx]) // Don't overwrite correct entries
TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[idx], VALUE_NONE);
assert(MoveList<LEGAL>(pos).contains(pv[idx]));
-
- pos.do_move(pv[idx++], *st++);
-
- } while (pv[idx] != MOVE_NONE);
+ pos.do_move(pv[idx], *st++);
+ }
while (idx) pos.undo_move(pv[--idx]);
}
Threads.mutex.unlock();
- Stack stack[MAX_PLY_PLUS_6], *ss = stack+2; // To allow referencing (ss-2)
+ Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
Position pos(*sp->pos, this);
std::memcpy(ss-2, sp->ss-2, 5 * sizeof(Stack));
void check_time() {
static Time::point lastInfoTime = Time::now();
- int64_t nodes = 0; // Workaround silly 'uninitialized' gcc warning
+ Time::point elapsed = Time::now() - SearchTime;
if (Time::now() - lastInfoTime >= 1000)
{
dbg_print();
}
- if (Limits.ponder)
- return;
+ if (Limits.use_time_management() && !Limits.ponder)
+ {
+ bool stillAtFirstMove = Signals.firstRootMove
+ && !Signals.failedLowAtRoot
+ && elapsed > TimeMgr.available_time() * 75 / 100;
+
+ if ( stillAtFirstMove
+ || elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution)
+ Signals.stop = true;
+ }
+ else if (Limits.movetime && elapsed >= Limits.movetime)
+ Signals.stop = true;
- if (Limits.nodes)
+ else if (Limits.nodes)
{
Threads.mutex.lock();
- nodes = RootPos.nodes_searched();
+ int64_t nodes = RootPos.nodes_searched();
// Loop across all split points and sum accumulated SplitPoint nodes plus
// all the currently active positions nodes.
}
Threads.mutex.unlock();
- }
-
- Time::point elapsed = Time::now() - SearchTime;
- bool stillAtFirstMove = Signals.firstRootMove
- && !Signals.failedLowAtRoot
- && elapsed > TimeMgr.available_time() * 75 / 100;
-
- bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution
- || stillAtFirstMove;
- if ( (Limits.use_time_management() && noMoreTime)
- || (Limits.movetime && elapsed >= Limits.movetime)
- || (Limits.nodes && nodes >= Limits.nodes))
- Signals.stop = true;
+ if (nodes >= Limits.nodes)
+ Signals.stop = true;
+ }
}