// Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply
const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) };
- // The main transposition table
- TranspositionTable TT;
-
/// Variables initialized by UCI options
Depth ThreatDepth; // heavy SMP read access
// Last seconds noise filtering (LSN)
- bool UseLSNFiltering;
- bool looseOnTime = false;
- int LSNTime; // In milliseconds
- Value LSNValue;
+ const bool UseLSNFiltering = true;
+ const int LSNTime = 4000; // In milliseconds
+ const Value LSNValue = value_from_centipawns(200);
+ bool loseOnTime = false;
// Extensions. Array index 0 is used at non-PV nodes, index 1 at PV nodes.
// There is heavy SMP read access on these arrays
// Time managment variables
int SearchStartTime;
int MaxNodes, MaxDepth;
- int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime;
- Move EasyMove;
+ int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime, ExactMaxTime;
int RootMoveNumber;
bool InfiniteSearch;
bool PonderSearch;
bool FailHigh;
bool FailLow;
bool Problem;
- bool PonderingEnabled;
- int ExactMaxTime;
// Show current line?
bool ShowCurrentLine;
int NodesSincePoll;
int NodesBetweenPolls = 30000;
+ // History table
+ History H;
+
/// Functions
bool move_is_killer(Move m, const SearchStack& ss);
Depth extension(const Position& pos, Move m, bool pvNode, bool capture, bool check, bool singleReply, bool mateThreat, bool* dangerous);
bool ok_to_do_nullmove(const Position& pos);
- bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d, const History& H);
+ bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d);
bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply);
bool ok_to_history(const Position& pos, Move m);
- void update_history(const Position& pos, Move m, Depth depth, History& H, Move movesSearched[], int moveCount);
+ void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount);
void update_killers(Move m, SearchStack& ss);
bool fail_high_ply_1();
void ponderhit();
void print_current_line(SearchStack ss[], int ply, int threadID);
void wait_for_stop_or_ponderhit();
+ void init_ss_array(SearchStack ss[]);
void idle_loop(int threadID, SplitPoint* waitSp);
void init_split_point_stack();
// Initialize global search variables
Idle = false;
SearchStartTime = get_system_time();
- EasyMove = MOVE_NONE;
for (int i = 0; i < THREAD_MAX; i++)
{
Threads[i].nodes = 0ULL;
// Read UCI option values
TT.set_size(get_option_value_int("Hash"));
if (button_was_pressed("Clear Hash"))
+ {
TT.clear();
+ loseOnTime = false; // reset at the beginning of a new game
+ }
- PonderingEnabled = get_option_value_bool("Ponder");
+ bool PonderingEnabled = get_option_value_bool("Ponder");
MultiPV = get_option_value_int("MultiPV");
CheckExtension[1] = Depth(get_option_value_int("Check Extension (PV nodes)"));
if (UseLogFile)
LogFile.open(get_option_value_string("Search Log Filename").c_str(), std::ios::out | std::ios::app);
- UseLSNFiltering = get_option_value_bool("LSN filtering");
- LSNTime = get_option_value_int("LSN Time Margin (sec)") * 1000;
- LSNValue = value_from_centipawns(get_option_value_int("LSN Value Margin"));
-
MinimumSplitDepth = get_option_value_int("Minimum Split Depth") * OnePly;
MaxThreadsPerSplitPoint = get_option_value_int("Maximum Number of Threads per Split Point");
read_weights(pos.side_to_move());
+ // Set the number of active threads
int newActiveThreads = get_option_value_int("Threads");
if (newActiveThreads != ActiveThreads)
{
if (movesToGo == 1)
{
MaxSearchTime = myTime / 2;
- AbsoluteMaxSearchTime = Min(myTime / 2, myTime - 500);
+ AbsoluteMaxSearchTime =
+ (myTime > 3000)? (myTime - 500) : ((myTime * 3) / 4);
} else {
MaxSearchTime = myTime / Min(movesToGo, 20);
AbsoluteMaxSearchTime = Min((4 * myTime) / movesToGo, myTime / 3);
NodesBetweenPolls = Min(MaxNodes, 30000);
InfiniteSearch = true; // HACK
}
+ else if (myTime && myTime < 1000)
+ NodesBetweenPolls = 1000;
+ else if (myTime && myTime < 5000)
+ NodesBetweenPolls = 5000;
else
NodesBetweenPolls = 30000;
-
// Write information to search log file
if (UseLogFile)
LogFile << "Searching: " << pos.to_fen() << std::endl
// We're ready to start thinking. Call the iterative deepening loop function
- if (!looseOnTime)
+ //
+ // FIXME we really need to cleanup all this LSN ugliness
+ if (!loseOnTime)
{
Value v = id_loop(pos, searchMoves);
- looseOnTime = ( UseLSNFiltering
- && myTime < LSNTime
- && myIncrement == 0
- && v < -LSNValue);
+ loseOnTime = ( UseLSNFiltering
+ && myTime < LSNTime
+ && myIncrement == 0
+ && v < -LSNValue);
}
else
{
- looseOnTime = false; // reset for next match
+ loseOnTime = false; // reset for next match
while (SearchStartTime + myTime + 1000 > get_system_time())
; // wait here
id_loop(pos, searchMoves); // to fail gracefully
// searchMoves are verified, copied, scored and sorted
RootMoveList rml(p, searchMoves);
+ // Print RootMoveList c'tor startup scoring to the standard output,
+ // so that we print information also for iteration 1.
+ std::cout << "info depth " << 1 << "\ninfo depth " << 1
+ << " score " << value_to_string(rml.get_move_score(0))
+ << " time " << current_search_time()
+ << " nodes " << nodes_searched()
+ << " nps " << nps()
+ << " pv " << rml.get_move(0) << "\n";
+
// Initialize
TT.new_search();
- for (int i = 0; i < THREAD_MAX; i++)
- Threads[i].H.clear();
-
- for (int i = 0; i < 3; i++)
- {
- ss[i].init(i);
- ss[i].initKillers();
- }
+ H.clear();
+ init_ss_array(ss);
IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0));
Iteration = 1;
- EasyMove = rml.scan_for_easy_move();
+ Move EasyMove = rml.scan_for_easy_move();
// Iterative deepening loop
while (Iteration < PLY_MAX)
<< " currmovenumber " << i + 1 << std::endl;
// Decide search depth for this move
+ bool moveIsCapture = pos.move_is_capture(move);
bool dangerous;
- ext = extension(pos, move, true, pos.move_is_capture(move), pos.move_is_check(move), false, false, &dangerous);
+ ext = extension(pos, move, true, moveIsCapture, pos.move_is_check(move), false, false, &dangerous);
newDepth = (Iteration - 2) * OnePly + ext + InitialDepth;
// Make the move, and search it
}
else
{
- value = -search(pos, ss, -alpha, newDepth, 1, true, 0);
+ if ( newDepth >= 3*OnePly
+ && i >= MultiPV + LMRPVMoves
+ && !dangerous
+ && !moveIsCapture
+ && !move_is_promotion(move)
+ && !move_is_castle(move))
+ {
+ ss[0].reduction = OnePly;
+ value = -search(pos, ss, -alpha, newDepth-OnePly, 1, true, 0);
+ } else
+ value = alpha + 1; // Just to trigger next condition
+
if (value > alpha)
{
- // Fail high! Set the boolean variable FailHigh to true, and
- // re-search the move with a big window. The variable FailHigh is
- // used for time managment: We try to avoid aborting the search
- // prematurely during a fail high research.
- FailHigh = true;
- value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0);
+ value = -search(pos, ss, -alpha, newDepth, 1, true, 0);
+ if (value > alpha)
+ {
+ // Fail high! Set the boolean variable FailHigh to true, and
+ // re-search the move with a big window. The variable FailHigh is
+ // used for time managment: We try to avoid aborting the search
+ // prematurely during a fail high research.
+ FailHigh = true;
+ value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0);
+ }
}
}
// Update PV
rml.set_move_score(i, value);
update_pv(ss, 0);
+ TT.extract_pv(pos, ss[0].pv, PLY_MAX);
rml.set_move_pv(i, ss[0].pv);
if (MultiPV == 1)
// Print search information to the standard output
std::cout << "info depth " << Iteration
<< " score " << value_to_string(value)
+ << ((value >= beta)?
+ " lowerbound" : ((value <= alpha)? " upperbound" : ""))
<< " time " << current_search_time()
<< " nodes " << nodes_searched()
<< " nps " << nps()
std::cout << std::endl;
if (UseLogFile)
- LogFile << pretty_pv(pos, current_search_time(), Iteration, nodes_searched(), value, ss[0].pv)
+ LogFile << pretty_pv(pos, current_search_time(), Iteration, nodes_searched(), value,
+ ((value >= beta)? VALUE_TYPE_LOWER
+ : ((value <= alpha)? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT)),
+ ss[0].pv)
<< std::endl;
if (value > alpha)
EvalInfo ei;
if (ply >= PLY_MAX - 1)
- return evaluate(pos, ei, threadID);
+ return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
// Mate distance pruning
Value oldAlpha = alpha;
// Initialize a MovePicker object for the current position, and prepare
// to search all moves
- MovePicker mp = MovePicker(pos, ttMove, depth, Threads[threadID].H, &ss[ply]);
-
Move move, movesSearched[256];
int moveCount = 0;
Value value, bestValue = -VALUE_INFINITE;
- Bitboard dcCandidates = mp.discovered_check_candidates();
Color us = pos.side_to_move();
bool isCheck = pos.is_check();
bool mateThreat = pos.has_mate_threat(opposite_color(us));
+ MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
+ Bitboard dcCandidates = mp.discovered_check_candidates();
+
// Loop through all legal moves until no moves remain or a beta cutoff
// occurs.
while ( alpha < beta
{
assert(move_is_ok(move));
- bool singleReply = (isCheck && mp.number_of_moves() == 1);
+ bool singleReply = (isCheck && mp.number_of_evasions() == 1);
bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
{
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
- if ( depth >= 2*OnePly
+ if ( depth >= 3*OnePly
&& moveCount >= LMRPVMoves
&& !dangerous
&& !moveIsCapture
Move m = ss[ply].pv[ply];
if (ok_to_history(pos, m)) // Only non capture moves are considered
{
- update_history(pos, m, depth, Threads[threadID].H, movesSearched, moveCount);
+ update_history(pos, m, depth, movesSearched, moveCount);
update_killers(m, ss[ply]);
}
TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, m);
EvalInfo ei;
if (ply >= PLY_MAX - 1)
- return evaluate(pos, ei, threadID);
+ return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
// Mate distance pruning
if (value_mated_in(ply) >= beta)
pos.undo_null_move();
- if (value_is_mate(nullValue))
- {
- /* Do not return unproven mates */
- }
- else if (nullValue >= beta)
+ if (nullValue >= beta)
{
if (depth < 6 * OnePly)
return beta;
// Initialize a MovePicker object for the current position, and prepare
// to search all moves.
- MovePicker mp = MovePicker(pos, ttMove, depth, Threads[threadID].H, &ss[ply]);
+ MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
Move move, movesSearched[256];
int moveCount = 0;
bool useFutilityPruning = depth < SelectiveDepth
&& !isCheck;
+ // Avoid calling evaluate() if we already have the score in TT
+ if (tte && (tte->type() & VALUE_TYPE_EVAL))
+ futilityValue = value_from_tt(tte->value(), ply) + FutilityMargins[int(depth) - 2];
+
// Loop through all legal moves until no moves remain or a beta cutoff
// occurs.
while ( bestValue < beta
{
assert(move_is_ok(move));
- bool singleReply = (isCheck && mp.number_of_moves() == 1);
+ bool singleReply = (isCheck && mp.number_of_evasions() == 1);
bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
{
// History pruning. See ok_to_prune() definition
if ( moveCount >= 2 + int(depth)
- && ok_to_prune(pos, move, ss[ply].threatMove, depth, Threads[threadID].H))
+ && ok_to_prune(pos, move, ss[ply].threatMove, depth)
+ && bestValue > value_mated_in(PLY_MAX))
continue;
// Value based pruning
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
- if ( depth >= 2*OnePly
+ if ( depth >= 3*OnePly
&& moveCount >= LMRNonPVMoves
&& !dangerous
&& !moveIsCapture
Move m = ss[ply].pv[ply];
if (ok_to_history(pos, m)) // Only non capture moves are considered
{
- update_history(pos, m, depth, Threads[threadID].H, movesSearched, moveCount);
+ update_history(pos, m, depth, movesSearched, moveCount);
update_killers(m, ss[ply]);
}
TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, m);
if (isCheck)
staticValue = -VALUE_INFINITE;
- else if (tte && tte->type() == VALUE_TYPE_EVAL)
+ else if (tte && (tte->type() & VALUE_TYPE_EVAL))
{
// Use the cached evaluation score if possible
- assert(tte->value() == evaluate(pos, ei, threadID));
assert(ei.futilityMargin == Value(0));
staticValue = tte->value();
else
staticValue = evaluate(pos, ei, threadID);
- if (ply == PLY_MAX - 1)
- return evaluate(pos, ei, threadID);
+ if (ply >= PLY_MAX - 1)
+ return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID);
// Initialize "stand pat score", and return it immediately if it is
// at least beta.
{
// Store the score to avoid a future costly evaluation() call
if (!isCheck && !tte && ei.futilityMargin == 0)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EVAL, Depth(-127*OnePly), MOVE_NONE);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EV_LO, Depth(-127*OnePly), MOVE_NONE);
return bestValue;
}
// Initialize a MovePicker object for the current position, and prepare
// to search the moves. Because the depth is <= 0 here, only captures,
// queen promotions and checks (only if depth == 0) will be generated.
- MovePicker mp = MovePicker(pos, ttMove, depth, Threads[threadID].H);
+ MovePicker mp = MovePicker(pos, ttMove, depth, H);
Move move;
int moveCount = 0;
Bitboard dcCandidates = mp.discovered_check_candidates();
// Don't search captures and checks with negative SEE values
if ( !isCheck
&& !move_is_promotion(move)
- && (pos.midgame_value_of_piece_on(move_from(move)) >
- pos.midgame_value_of_piece_on(move_to(move)))
- && pos.see(move) < 0)
+ && pos.see_sign(move) < 0)
continue;
// Make and search the move.
Move m = ss[ply].pv[ply];
if (!pvNode)
{
+ // If bestValue isn't changed it means it is still the static evaluation of
+ // the node, so keep this info to avoid a future costly evaluation() call.
+ ValueType type = (bestValue == staticValue && !ei.futilityMargin ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER);
Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
+
if (bestValue < beta)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, d, MOVE_NONE);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), type, d, MOVE_NONE);
else
TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, m);
}
&& !moveIsCapture
&& !move_is_promotion(move)
&& moveCount >= 2 + int(sp->depth)
- && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth, Threads[threadID].H))
+ && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth))
continue;
// Make and search the move.
bool includeAllMoves = (searchMoves[0] == MOVE_NONE);
// Generate all legal moves
- int lm_count = generate_legal_moves(pos, mlist);
+ MoveStack* last = generate_moves(pos, mlist);
// Add each move to the moves[] array
- for (int i = 0; i < lm_count; i++)
+ for (MoveStack* cur = mlist; cur != last; cur++)
{
bool includeMove = includeAllMoves;
for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++)
- includeMove = (searchMoves[k] == mlist[i].move);
+ includeMove = (searchMoves[k] == cur->move);
if (!includeMove)
continue;
// Find a quick score for the move
StateInfo st;
SearchStack ss[PLY_MAX_PLUS_2];
+ init_ss_array(ss);
- moves[count].move = mlist[i].move;
+ moves[count].move = cur->move;
pos.do_move(moves[count].move, st);
moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0);
pos.undo_move(moves[count].move);
// the second move is assumed to be a move from the current position.
bool connected_moves(const Position& pos, Move m1, Move m2) {
+
Square f1, t1, f2, t2;
+ Piece p;
assert(move_is_ok(m1));
assert(move_is_ok(m2));
return true;
// Case 4: The destination square for m2 is attacked by the moving piece in m1
- if (pos.piece_attacks_square(pos.piece_on(t1), t1, t2))
+ p = pos.piece_on(t1);
+ if (bit_is_set(pos.attacks_from(p, t1), t2))
return true;
// Case 5: Discovered check, checking piece is the piece moved in m1
- if ( piece_is_slider(pos.piece_on(t1))
+ if ( piece_is_slider(p)
&& bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), f2)
- && !bit_is_set(squares_between(t2, pos.king_square(pos.side_to_move())), t2))
+ && !bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), t2))
{
Bitboard occ = pos.occupied_squares();
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
clear_bit(&occ, f2);
- if (pos.type_of_piece_on(t1) == BISHOP)
+ if (type_of_piece(p) == BISHOP)
{
if (bit_is_set(bishop_attacks_bb(ksq, occ), t1))
return true;
}
- else if (pos.type_of_piece_on(t1) == ROOK)
+ else if (type_of_piece(p) == ROOK)
{
if (bit_is_set(rook_attacks_bb(ksq, occ), t1))
return true;
}
else
{
- assert(pos.type_of_piece_on(t1) == QUEEN);
+ assert(type_of_piece(p) == QUEEN);
if (bit_is_set(queen_attacks_bb(ksq, occ), t1))
return true;
}
assert(m != MOVE_NONE);
Depth result = Depth(0);
- *dangerous = check || singleReply || mateThreat;
+ *dangerous = check | singleReply | mateThreat;
- if (check)
- result += CheckExtension[pvNode];
+ if (*dangerous)
+ {
+ if (check)
+ result += CheckExtension[pvNode];
- if (singleReply)
- result += SingleReplyExtension[pvNode];
+ if (singleReply)
+ result += SingleReplyExtension[pvNode];
- if (mateThreat)
- result += MateThreatExtension[pvNode];
+ if (mateThreat)
+ result += MateThreatExtension[pvNode];
+ }
if (pos.type_of_piece_on(move_from(m)) == PAWN)
{
- if (pos.move_is_pawn_push_to_7th(m))
+ Color c = pos.side_to_move();
+ if (relative_rank(c, move_to(m)) == RANK_7)
{
result += PawnPushTo7thExtension[pvNode];
*dangerous = true;
}
- if (pos.move_is_passed_pawn_push(m))
+ if (pos.pawn_is_passed(c, move_to(m)))
{
result += PassedPawnExtension[pvNode];
*dangerous = true;
if ( pvNode
&& capture
&& pos.type_of_piece_on(move_to(m)) != PAWN
- && pos.see(m) >= 0)
+ && pos.see_sign(m) >= 0)
{
result += OnePly/2;
*dangerous = true;
// non-tactical moves late in the move list close to the leaves are
// candidates for pruning.
- bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d, const History& H) {
+ bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d) {
assert(move_is_ok(m));
assert(threat == MOVE_NONE || move_is_ok(threat));
- assert(!move_promotion(m));
+ assert(!move_is_promotion(m));
assert(!pos.move_is_check(m));
assert(!pos.move_is_capture(m));
assert(!pos.move_is_passed_pawn_push(m));
&& threat != MOVE_NONE
&& piece_is_slider(pos.piece_on(tfrom))
&& bit_is_set(squares_between(tfrom, tto), mto)
- && pos.see(m) >= 0)
+ && pos.see_sign(m) >= 0)
return false;
return true;
// update_history() registers a good move that produced a beta-cutoff
// in history and marks as failures all the other moves of that ply.
- void update_history(const Position& pos, Move m, Depth depth, History& H,
+ void update_history(const Position& pos, Move m, Depth depth,
Move movesSearched[], int moveCount) {
H.success(pos.piece_on(move_from(m)), move_to(m), depth);
ss.killers[0] = m;
}
+
// fail_high_ply_1() checks if some thread is currently resolving a fail
// high at ply 1 at the node below the first root node. This information
// is used for time managment.
}
+ // init_ss_array() does a fast reset of the first entries of a SearchStack array
+
+ void init_ss_array(SearchStack ss[]) {
+
+ for (int i = 0; i < 3; i++)
+ {
+ ss[i].init(i);
+ ss[i].initKillers();
+ }
+ }
+
+
// wait_for_stop_or_ponderhit() is called when the maximum depth is reached
// while the program is pondering. The point is to work around a wrinkle in
// the UCI protocol: When pondering, the engine is not allowed to give a
projects / stockfish / blobdiff