using Eval::evaluate;
using namespace Search;
+// For some reason argument-dependent lookup (ADL) doesn't work for Android's
+// STLPort, so explicitly qualify following functions.
+using std::count;
+using std::find;
+
namespace {
// Set to true to force running with one thread. Used for debugging
const Depth RazorDepth = 4 * ONE_PLY;
// Dynamic razoring margin based on depth
- inline Value razor_margin(Depth d) { return Value(0x200 + 0x10 * int(d)); }
+ inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); }
// Maximum depth for use of dynamic threat detection when null move fails low
const Depth ThreatDepth = 5 * ONE_PLY;
// At Non-PV nodes we do an internal iterative deepening search
// when the static evaluation is bigger then beta - IIDMargin.
- const Value IIDMargin = Value(0x100);
+ const Value IIDMargin = Value(256);
// Minimum depth for use of singular extension
const Depth SingularExtensionDepth[] = { 8 * ONE_PLY, 6 * ONE_PLY };
// Futility margin for quiescence search
- const Value FutilityMarginQS = Value(0x80);
+ const Value FutilityMarginQS = Value(128);
// Futility lookup tables (initialized at startup) and their access functions
Value FutilityMargins[16][64]; // [depth][moveNumber]
Value refine_eval(const TTEntry* tte, Value ttValue, Value defaultEval);
Move do_skill_level();
string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE);
- void pv_info_to_log(Position& pos, int depth, Value score, int time, Move pv[]);
- void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta);
+ string pretty_pv(Position& pos, int depth, Value score, int time, Move pv[]);
+ string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
// MovePickerExt class template extends MovePicker and allows to choose at
// compile time the proper moves source according to the type of node. In the
// 'dangerous' moves so that we avoid to prune it.
FORCE_INLINE bool is_dangerous(const Position& pos, Move m, bool captureOrPromotion) {
- // Test for a pawn pushed to 7th or a passed pawn move
- if (type_of(pos.piece_moved(m)) == PAWN)
- {
- Color c = pos.side_to_move();
- if ( relative_rank(c, to_sq(m)) == RANK_7
- || pos.pawn_is_passed(c, to_sq(m)))
- return true;
- }
+ // Castle move?
+ if (type_of(m) == CASTLE)
+ return true;
- // Test for a capture that triggers a pawn endgame
- if ( captureOrPromotion
- && type_of(pos.piece_on(to_sq(m))) != PAWN
+ // Passed pawn move?
+ if ( type_of(pos.piece_moved(m)) == PAWN
+ && pos.pawn_is_passed(pos.side_to_move(), to_sq(m)))
+ return true;
+
+ // Entering a pawn endgame?
+ if ( captureOrPromotion
+ && type_of(pos.piece_on(to_sq(m))) != PAWN
+ && type_of(m) == NORMAL
&& ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
- - PieceValueMidgame[pos.piece_on(to_sq(m))] == VALUE_ZERO)
- && !is_special(m))
+ - PieceValueMidgame[pos.piece_on(to_sq(m))] == VALUE_ZERO))
return true;
return false;
StateInfo st;
int64_t cnt = 0;
- MoveList<MV_LEGAL> ml(pos);
+ MoveList<LEGAL> ml(pos);
// At the last ply just return the number of moves (leaf nodes)
if (depth == ONE_PLY)
goto finalize;
}
- if (Options["OwnBook"])
+ if (Options["OwnBook"] && !Limits.infinite)
{
Move bookMove = book.probe(pos, Options["Book File"], Options["Best Book Move"]);
// Send full PV info to GUI if we are going to leave the loop or
// if we have a fail high/low and we are deep in the search.
if ((bestValue > alpha && bestValue < beta) || SearchTime.elapsed() > 2000)
- pv_info_to_uci(pos, depth, alpha, beta);
+ cout << uci_pv(pos, depth, alpha, beta) << endl;
// In case of failing high/low increase aspiration window and
// research, otherwise exit the fail high/low loop.
skillBest = do_skill_level();
if (!Signals.stop && Options["Use Search Log"])
- pv_info_to_log(pos, depth, bestValue, SearchTime.elapsed(), &RootMoves[0].pv[0]);
+ {
+ Log log(Options["Search Log Filename"]);
+ log << pretty_pv(pos, depth, bestValue, SearchTime.elapsed(), &RootMoves[0].pv[0])
+ << endl;
+ }
// Filter out startup noise when monitoring best move stability
if (depth > 2 && BestMoveChanges)
assert((alpha == beta - 1) || PvNode);
assert(depth > DEPTH_ZERO);
- Move movesSearched[MAX_MOVES];
+ Move movesSearched[64];
StateInfo st;
const TTEntry *tte;
Key posKey;
TT.refresh(tte);
ss->currentMove = ttMove; // Can be MOVE_NONE
- if ( ttValue >= beta
- && ttMove
+ if ( ttValue >= beta
+ && ttMove
&& !pos.is_capture_or_promotion(ttMove)
- && ttMove != ss->killers[0])
+ && ttMove != ss->killers[0])
{
ss->killers[1] = ss->killers[0];
ss->killers[0] = ttMove;
// Update gain for the parent non-capture move given the static position
// evaluation before and after the move.
- if ( (move = (ss-1)->currentMove) != MOVE_NULL
- && (ss-1)->eval != VALUE_NONE
- && ss->eval != VALUE_NONE
+ if ( (move = (ss-1)->currentMove) != MOVE_NULL
+ && (ss-1)->eval != VALUE_NONE
+ && ss->eval != VALUE_NONE
&& !pos.captured_piece_type()
- && !is_special(move))
+ && type_of(move) == NORMAL)
{
Square to = to_sq(move);
H.update_gain(pos.piece_on(to), to, -(ss-1)->eval - ss->eval);
ss->currentMove = MOVE_NULL;
// Null move dynamic reduction based on depth
- int R = 3 + (depth >= 5 * ONE_PLY ? depth / 8 : 0);
+ Depth R = 3 * ONE_PLY + depth / 4;
// Null move dynamic reduction based on value
if (refinedValue - PawnValueMidgame > beta)
- R++;
+ R += ONE_PLY;
pos.do_null_move<true>(st);
(ss+1)->skipNullMove = true;
- nullValue = depth-R*ONE_PLY < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
- : - search<NonPV>(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY);
+ nullValue = depth-R < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
+ : - search<NonPV>(pos, ss+1, -beta, -alpha, depth-R);
(ss+1)->skipNullMove = false;
pos.do_null_move<false>(st);
// Do verification search at high depths
ss->skipNullMove = true;
- Value v = search<NonPV>(pos, ss, alpha, beta, depth-R*ONE_PLY);
+ Value v = search<NonPV>(pos, ss, alpha, beta, depth-R);
ss->skipNullMove = false;
if (v >= beta)
futilityBase = ss->eval + ss->evalMargin;
singularExtensionNode = !RootNode
&& !SpNode
- && depth >= SingularExtensionDepth[PvNode]
- && ttMove != MOVE_NONE
+ && depth >= SingularExtensionDepth[PvNode]
+ && ttMove != MOVE_NONE
&& !excludedMove // Recursive singular search is not allowed
&& (tte->type() & BOUND_LOWER)
- && tte->depth() >= depth - 3 * ONE_PLY;
+ && tte->depth() >= depth - 3 * ONE_PLY;
// Step 11. Loop through moves
// Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
- while ( bestValue < beta
+ while ( bestValue < beta
&& (move = mp.next_move()) != MOVE_NONE
&& !thisThread->cutoff_occurred()
&& !Signals.stop)
ext = ONE_PLY;
else if (givesCheck && pos.see_sign(move) >= 0)
- ext = PvNode ? ONE_PLY : ONE_PLY / 2;
+ ext = ONE_PLY / 2;
// Singular extension search. If all moves but one fail low on a search of
// (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
// is singular and should be extended. To verify this we do a reduced search
// on all the other moves but the ttMove, if result is lower than ttValue minus
// a margin then we extend ttMove.
- if ( singularExtensionNode
+ if ( singularExtensionNode
&& !ext
- && move == ttMove
- && pos.pl_move_is_legal(move, ci.pinned))
+ && move == ttMove
+ && pos.pl_move_is_legal(move, ci.pinned)
+ && abs(ttValue) < VALUE_KNOWN_WIN)
{
- if (abs(ttValue) < VALUE_KNOWN_WIN)
- {
- Value rBeta = ttValue - int(depth);
- ss->excludedMove = move;
- ss->skipNullMove = true;
- value = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth / 2);
- ss->skipNullMove = false;
- ss->excludedMove = MOVE_NONE;
- if (value < rBeta)
- ext = ONE_PLY;
- }
+ Value rBeta = ttValue - int(depth);
+ ss->excludedMove = move;
+ ss->skipNullMove = true;
+ value = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth / 2);
+ ss->skipNullMove = false;
+ ss->excludedMove = MOVE_NONE;
+
+ if (value < rBeta)
+ ext = ONE_PLY;
}
// Update current move (this must be done after singular extension search)
&& !inCheck
&& !dangerous
&& move != ttMove
- && !is_castle(move)
&& (bestValue > VALUE_MATED_IN_MAX_PLY || bestValue == -VALUE_INFINITE))
{
// Move count based pruning
}
ss->currentMove = move;
- if (!SpNode && !captureOrPromotion)
+ if (!SpNode && !captureOrPromotion && playedMoveCount < 64)
movesSearched[playedMoveCount++] = move;
// Step 14. Make the move
// Step 15. Reduced depth search (LMR). If the move fails high will be
// re-searched at full depth.
- if ( depth > 3 * ONE_PLY
+ if ( depth > 3 * ONE_PLY
&& !isPvMove
&& !captureOrPromotion
&& !dangerous
- && !is_castle(move)
&& ss->killers[0] != move
&& ss->killers[1] != move)
{
// Step 19. Check for split
if ( !SpNode
- && depth >= Threads.min_split_depth()
- && bestValue < beta
- && Threads.available_slave_exists(thisThread)
+ && depth >= Threads.min_split_depth()
+ && bestValue < beta
+ && Threads.available_slave_exists(thisThread)
&& !Signals.stop
&& !thisThread->cutoff_occurred())
bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, &bestMove,
&& !givesCheck
&& move != ttMove
&& enoughMaterial
- && !is_promotion(move)
+ && type_of(move) != PROMOTION
&& !pos.is_passed_pawn_push(move))
{
futilityValue = futilityBase
+ PieceValueEndgame[pos.piece_on(to_sq(move))]
- + (is_enpassant(move) ? PawnValueEndgame : VALUE_ZERO);
+ + (type_of(move) == ENPASSANT ? PawnValueEndgame : VALUE_ZERO);
if (futilityValue < beta)
{
// Detect non-capture evasions that are candidate to be pruned
evasionPrunable = !PvNode
- && inCheck
- && bestValue > VALUE_MATED_IN_MAX_PLY
+ && inCheck
+ && bestValue > VALUE_MATED_IN_MAX_PLY
&& !pos.is_capture(move)
&& !pos.can_castle(pos.side_to_move());
if ( !PvNode
&& (!inCheck || evasionPrunable)
&& move != ttMove
- && !is_promotion(move)
+ && type_of(move) != PROMOTION
&& pos.see_sign(move) < 0)
continue;
// Rule 1. Checks which give opponent's king at most one escape square are dangerous
b = kingAtt & ~pos.pieces(them) & ~newAtt & ~(1ULL << to);
- if (single_bit(b)) // Catches also !b
+ if (!more_than_one(b))
return true;
// Rule 2. Queen contact check is very dangerous
while (b)
{
// Note that here we generate illegal "double move"!
- if (futilityBase + PieceValueEndgame[pos.piece_on(pop_1st_bit(&b))] >= beta)
+ if (futilityBase + PieceValueEndgame[pos.piece_on(pop_lsb(&b))] >= beta)
return true;
}
// Case 3: Moving through the vacated square
p2 = pos.piece_on(f2);
- if (piece_is_slider(p2) && (squares_between(f2, t2) & f1))
+ if (piece_is_slider(p2) && (between_bb(f2, t2) & f1))
return true;
// Case 4: The destination square for m2 is defended by the moving piece in m1
// Case 5: Discovered check, checking piece is the piece moved in m1
ksq = pos.king_square(pos.side_to_move());
if ( piece_is_slider(p1)
- && (squares_between(t1, ksq) & f2)
+ && (between_bb(t1, ksq) & f2)
&& (pos.attacks_from(p1, t1, pos.pieces() ^ f2) & ksq))
return true;
// Case 3: If the moving piece in the threatened move is a slider, don't
// prune safe moves which block its ray.
if ( piece_is_slider(pos.piece_on(tfrom))
- && (squares_between(tfrom, tto) & mto)
+ && (between_bb(tfrom, tto) & mto)
&& pos.see_sign(m) >= 0)
return true;
}
- // pv_info_to_uci() sends search info to GUI. UCI protocol requires to send all
- // the PV lines also if are still to be searched and so refer to the previous
- // search score.
+ // uci_pv() formats PV information according to UCI protocol. UCI requires
+ // to send all the PV lines also if are still to be searched and so refer to
+ // the previous search score.
- void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta) {
+ string uci_pv(const Position& pos, int depth, Value alpha, Value beta) {
+ std::stringstream s;
int t = SearchTime.elapsed();
int selDepth = 0;
int d = (updated ? depth : depth - 1);
Value v = (updated ? RootMoves[i].score : RootMoves[i].prevScore);
- std::stringstream s;
- for (int j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++)
- s << " " << move_to_uci(RootMoves[i].pv[j], Chess960);
+ if (s.rdbuf()->in_avail())
+ s << "\n";
- cout << "info depth " << d
- << " seldepth " << selDepth
- << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
- << " nodes " << pos.nodes_searched()
- << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0)
- << " time " << t
- << " multipv " << i + 1
- << " pv" << s.str() << endl;
+ s << "info depth " << d
+ << " seldepth " << selDepth
+ << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
+ << " nodes " << pos.nodes_searched()
+ << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0)
+ << " time " << t
+ << " multipv " << i + 1
+ << " pv";
+
+ for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++)
+ s << " " << move_to_uci(RootMoves[i].pv[j], Chess960);
}
+
+ return s.str();
}
- // pv_info_to_log() writes human-readable search information to the log file
- // (which is created when the UCI parameter "Use Search Log" is "true"). It
- // uses the two below helpers to pretty format time and score respectively.
+ // pretty_pv() formats human-readable search information, typically to be
+ // appended to the search log file. It uses the two helpers below to pretty
+ // format time and score respectively.
string time_to_string(int millisecs) {
if (v >= VALUE_MATE_IN_MAX_PLY)
s << "#" << (VALUE_MATE - v + 1) / 2;
+
else if (v <= VALUE_MATED_IN_MAX_PLY)
s << "-#" << (VALUE_MATE + v) / 2;
+
else
s << std::setprecision(2) << std::fixed << std::showpos
<< float(v) / PawnValueMidgame;
return s.str();
}
- void pv_info_to_log(Position& pos, int depth, Value value, int time, Move pv[]) {
+ string pretty_pv(Position& pos, int depth, Value value, int time, Move pv[]) {
const int64_t K = 1000;
const int64_t M = 1000000;
while (m != pv)
pos.undo_move(*--m);
- Log l(Options["Search Log Filename"]);
- l << s.str() << endl;
+ return s.str();
}
// Wake up master thread so to allow it to return from the idle loop in
// case we are the last slave of the split point.
- if ( Threads.use_sleeping_threads()
- && this != sp->master
+ if ( Threads.use_sleeping_threads()
+ && this != sp->master
&& !sp->master->is_searching)
sp->master->wake_up();