#include "evaluate.h"
#include "history.h"
#include "misc.h"
+#include "move.h"
#include "movegen.h"
#include "movepick.h"
#include "lock.h"
-#include "san.h"
#include "search.h"
#include "timeman.h"
#include "thread.h"
void extract_pv_from_tt(Position& pos);
void insert_pv_in_tt(Position& pos);
- std::string pv_info_to_uci(const Position& pos, Value alpha, Value beta, int pvLine = 0);
+ std::string pv_info_to_uci(Position& pos, Value alpha, Value beta, int pvLine = 0);
int64_t nodes;
Value pv_score;
typedef std::vector<RootMove> Base;
RootMoveList(Position& pos, Move searchMoves[]);
- void set_non_pv_scores(const Position& pos);
+ void set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss);
void sort() { insertion_sort<RootMove, Base::iterator>(begin(), end()); }
void sort_multipv(int n) { insertion_sort<RootMove, Base::iterator>(begin(), begin() + n); }
// operator<<() that will use it to properly format castling moves.
enum set960 {};
- std::ostream& operator<< (std::ostream& os, const set960& m) {
+ std::ostream& operator<< (std::ostream& os, const set960& f) {
- os.iword(0) = int(m);
+ os.iword(0) = int(f);
return os;
}
+ // Overload operator << for moves to make it easier to print moves in
+ // coordinate notation compatible with UCI protocol.
+ std::ostream& operator<<(std::ostream& os, Move m) {
+
+ bool chess960 = (os.iword(0) != 0); // See set960()
+ return os << move_to_uci(m, chess960);
+ }
+
+
/// Adjustments
// Step 6. Razoring
// Book object
Book OpeningBook;
+ // Pointer to root move list
+ RootMoveList* Rml;
+
// Iteration counter
int Iteration;
// Time managment variables
int SearchStartTime, MaxNodes, MaxDepth, ExactMaxTime;
- bool UseTimeManagement, InfiniteSearch, PonderSearch, StopOnPonderhit;
- bool FirstRootMove, AbortSearch, Quit, AspirationFailLow;
+ bool UseTimeManagement, InfiniteSearch, Pondering, StopOnPonderhit;
+ bool FirstRootMove, StopRequest, QuitRequest, AspirationFailLow;
TimeManager TimeMgr;
// Log file
// Node counters, used only by thread[0] but try to keep in different cache
// lines (64 bytes each) from the heavy multi-thread read accessed variables.
+ bool SendSearchedNodes;
int NodesSincePoll;
int NodesBetweenPolls = 30000;
/// Local functions
Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove);
- Value root_search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, RootMoveList& rml);
- template <NodeType PvNode, bool SpNode>
+ template <NodeType PvNode, bool SpNode, bool Root>
Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply);
template <NodeType PvNode>
inline Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) {
return depth < ONE_PLY ? qsearch<PvNode>(pos, ss, alpha, beta, DEPTH_ZERO, ply)
- : search<PvNode, false>(pos, ss, alpha, beta, depth, ply);
+ : search<PvNode, false, false>(pos, ss, alpha, beta, depth, ply);
}
template <NodeType PvNode>
bool connected_threat(const Position& pos, Move m, Move threat);
Value refine_eval(const TTEntry* tte, Value defaultEval, int ply);
void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
- void update_killers(Move m, SearchStack* ss);
+ void update_killers(Move m, Move killers[]);
void update_gains(const Position& pos, Move move, Value before, Value after);
int current_search_time();
std::string value_to_uci(Value v);
int nps(const Position& pos);
void poll(const Position& pos);
- void ponderhit();
void wait_for_stop_or_ponderhit();
void init_ss_array(SearchStack* ss, int size);
DWORD WINAPI init_thread(LPVOID threadID);
#endif
-}
+
+ // A dispatcher to choose among different move sources according to the type of node
+ template<bool SpNode, bool Root> struct MovePickerExt;
+
+ // In Root nodes use RootMoveList Rml as source
+ template<> struct MovePickerExt<false, true> {
+
+ MovePickerExt(const Position&, Move, Depth, const History&, SearchStack*, Value)
+ : rm(Rml->begin()), firstCall(true) {}
+
+ Move get_next_move() {
+
+ if (!firstCall)
+ ++rm;
+ else
+ firstCall = false;
+
+ return rm != Rml->end() ? rm->pv[0] : MOVE_NONE;
+ }
+ int number_of_evasions() const { return (int)Rml->size(); }
+
+ RootMoveList::iterator rm;
+ bool firstCall;
+ };
+
+ // In SpNodes use split point's shared MovePicker as move source
+ template<> struct MovePickerExt<true, false> {
+
+ MovePickerExt(const Position&, Move, Depth, const History&, SearchStack* ss, Value)
+ : mp(ss->sp->mp) {}
+
+ Move get_next_move() { return mp->get_next_move(); }
+ int number_of_evasions() const { return mp->number_of_evasions(); }
+
+ RootMoveList::iterator rm; // Dummy, never used
+ MovePicker* mp;
+ };
+
+ // Normal case, create and use a MovePicker object as source
+ template<> struct MovePickerExt<false, false> : public MovePicker {
+
+ MovePickerExt(const Position& p, Move ttm, Depth d, const History& h,
+ SearchStack* ss, Value beta) : MovePicker(p, ttm, d, h, ss, beta) {}
+
+ RootMoveList::iterator rm; // Dummy, never used
+ };
+
+} // namespace
////
/// perft() is our utility to verify move generation is bug free. All the legal
/// moves up to given depth are generated and counted and the sum returned.
-int perft(Position& pos, Depth depth)
+int64_t perft(Position& pos, Depth depth)
{
MoveStack mlist[MOVES_MAX];
StateInfo st;
Move m;
- int sum = 0;
+ int64_t sum = 0;
// Generate all legal moves
- MoveStack* last = generate_moves(pos, mlist);
+ MoveStack* last = generate<MV_LEGAL>(pos, mlist);
// If we are at the last ply we don't need to do and undo
// the moves, just to count them.
/// think() is the external interface to Stockfish's search, and is called when
/// the program receives the UCI 'go' command. It initializes various
-/// search-related global variables, and calls root_search(). It returns false
+/// search-related global variables, and calls id_loop(). It returns false
/// when a quit command is received during the search.
bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[],
int movesToGo, int maxDepth, int maxNodes, int maxTime, Move searchMoves[]) {
// Initialize global search variables
- StopOnPonderhit = AbortSearch = Quit = AspirationFailLow = false;
+ StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = SendSearchedNodes = false;
NodesSincePoll = 0;
SearchStartTime = get_system_time();
ExactMaxTime = maxTime;
MaxDepth = maxDepth;
MaxNodes = maxNodes;
InfiniteSearch = infinite;
- PonderSearch = ponder;
+ Pondering = ponder;
UseTimeManagement = !ExactMaxTime && !MaxDepth && !MaxNodes && !InfiniteSearch;
// Look for a book move, only during games, not tests
if (UseTimeManagement && Options["OwnBook"].value<bool>())
{
- if (Options["Book File"].value<std::string>() != OpeningBook.file_name())
+ if (Options["Book File"].value<std::string>() != OpeningBook.name())
OpeningBook.open(Options["Book File"].value<std::string>());
Move bookMove = OpeningBook.get_move(pos, Options["Best Book Move"].value<bool>());
if (bookMove != MOVE_NONE)
{
- if (PonderSearch)
+ if (Pondering)
wait_for_stop_or_ponderhit();
cout << "bestmove " << bookMove << endl;
- return true;
+ return !QuitRequest;
}
}
<< move_to_san(pos, ponderMove) // Works also with MOVE_NONE
<< endl;
+ // Return from think() with unchanged position
+ pos.undo_move(bestMove);
+
LogFile.close();
}
// If we are pondering or in infinite search, we shouldn't print the
// best move before we are told to do so.
- if (!AbortSearch && (PonderSearch || InfiniteSearch))
+ if (!StopRequest && (Pondering || InfiniteSearch))
wait_for_stop_or_ponderhit();
// Could be both MOVE_NONE when searching on a stalemate position
cout << "bestmove " << bestMove << " ponder " << ponderMove << endl;
- return !Quit;
+ return !QuitRequest;
}
namespace {
- // id_loop() is the main iterative deepening loop. It calls root_search
+ // id_loop() is the main iterative deepening loop. It calls search()
// repeatedly with increasing depth until the allocated thinking time has
// been consumed, the user stops the search, or the maximum search depth is
// reached.
Depth depth;
Move EasyMove = MOVE_NONE;
Value value, alpha = -VALUE_INFINITE, beta = VALUE_INFINITE;
+ int researchCountFL, researchCountFH;
// Moves to search are verified, scored and sorted
RootMoveList rml(pos, searchMoves);
+ Rml = &rml;
// Handle special case of searching on a mate/stale position
if (rml.size() == 0)
depth = (Iteration - 2) * ONE_PLY + InitialDepth;
- // Search to the current depth, rml is updated and sorted
- value = root_search(pos, ss, alpha, beta, depth, rml);
+ researchCountFL = researchCountFH = 0;
+
+ // We start with small aspiration window and in case of fail high/low, we
+ // research with bigger window until we are not failing high/low anymore.
+ while (true)
+ {
+ // Sort the moves before to (re)search
+ rml.set_non_pv_scores(pos, rml[0].pv[0], ss);
+ rml.sort();
+
+ // Search to the current depth, rml is updated and sorted
+ value = search<PV, false, true>(pos, ss, alpha, beta, depth, 0);
+
+ // Sort the moves before to return
+ rml.sort();
+
+ // Write PV lines to transposition table, in case the relevant entries
+ // have been overwritten during the search.
+ for (int i = 0; i < Min(MultiPV, (int)rml.size()); i++)
+ rml[i].insert_pv_in_tt(pos);
+
+ if (StopRequest)
+ break;
+
+ assert(value >= alpha);
+
+ if (value >= beta)
+ {
+ // Prepare for a research after a fail high, each time with a wider window
+ beta = Min(beta + AspirationDelta * (1 << researchCountFH), VALUE_INFINITE);
+ researchCountFH++;
+ }
+ else if (value <= alpha)
+ {
+ AspirationFailLow = true;
+ StopOnPonderhit = false;
+
+ // Prepare for a research after a fail low, each time with a wider window
+ alpha = Max(alpha - AspirationDelta * (1 << researchCountFL), -VALUE_INFINITE);
+ researchCountFL++;
+ }
+ else
+ break;
+ }
- if (AbortSearch)
+ if (StopRequest)
break; // Value cannot be trusted. Break out immediately!
//Save info about search result
stopSearch = true;
// Stop search early when the last two iterations returned a mate score
- if ( Iteration >= 6
+ if ( Iteration >= 6
&& abs(ValueByIteration[Iteration]) >= abs(VALUE_MATE) - 100
&& abs(ValueByIteration[Iteration-1]) >= abs(VALUE_MATE) - 100)
stopSearch = true;
if (stopSearch)
{
- if (PonderSearch)
+ if (Pondering)
StopOnPonderhit = true;
else
break;
}
- // root_search() is the function which searches the root node. It is
- // similar to search_pv except that it prints some information to the
- // standard output and handles the fail low/high loops.
-
- Value root_search(Position& pos, SearchStack* ss, Value alpha,
- Value beta, Depth depth, RootMoveList& rml) {
- StateInfo st;
- CheckInfo ci(pos);
- int64_t nodes;
- Move move;
- Depth ext, newDepth;
- Value value, oldAlpha;
- bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
- int researchCountFH, researchCountFL;
-
- researchCountFH = researchCountFL = 0;
- oldAlpha = alpha;
- isCheck = pos.is_check();
-
- // Step 1. Initialize node (polling is omitted at root)
- ss->currentMove = ss->bestMove = MOVE_NONE;
-
- // Step 2. Check for aborted search (omitted at root)
- // Step 3. Mate distance pruning (omitted at root)
- // Step 4. Transposition table lookup (omitted at root)
-
- // Step 5. Evaluate the position statically
- // At root we do this only to get reference value for child nodes
- ss->evalMargin = VALUE_NONE;
- ss->eval = isCheck ? VALUE_NONE : evaluate(pos, ss->evalMargin);
-
- // Step 6. Razoring (omitted at root)
- // Step 7. Static null move pruning (omitted at root)
- // Step 8. Null move search with verification search (omitted at root)
- // Step 9. Internal iterative deepening (omitted at root)
-
- // Step extra. Fail low loop
- // We start with small aspiration window and in case of fail low, we research
- // with bigger window until we are not failing low anymore.
- while (1)
- {
- // Sort the moves before to (re)search
- rml.set_non_pv_scores(pos);
- rml.sort();
-
- // Step 10. Loop through all moves in the root move list
- for (int i = 0; i < (int)rml.size() && !AbortSearch; i++)
- {
- // This is used by time management
- FirstRootMove = (i == 0);
-
- // Save the current node count before the move is searched
- nodes = pos.nodes_searched();
-
- // Pick the next root move, and print the move and the move number to
- // the standard output.
- move = ss->currentMove = rml[i].pv[0];
-
- if (current_search_time() >= 1000)
- cout << "info currmove " << move
- << " currmovenumber " << i + 1 << endl;
-
- moveIsCheck = pos.move_is_check(move);
- captureOrPromotion = pos.move_is_capture_or_promotion(move);
-
- // Step 11. Decide the new search depth
- ext = extension<PV>(pos, move, captureOrPromotion, moveIsCheck, false, false, &dangerous);
- newDepth = depth + ext;
-
- // Step 12. Futility pruning (omitted at root)
-
- // Step extra. Fail high loop
- // If move fails high, we research with bigger window until we are not failing
- // high anymore.
- value = -VALUE_INFINITE;
-
- while (1)
- {
- // Step 13. Make the move
- pos.do_move(move, st, ci, moveIsCheck);
-
- // Step extra. pv search
- // We do pv search for first moves (i < MultiPV)
- // and for fail high research (value > alpha)
- if (i < MultiPV || value > alpha)
- {
- // Aspiration window is disabled in multi-pv case
- if (MultiPV > 1)
- alpha = -VALUE_INFINITE;
-
- // Full depth PV search, done on first move or after a fail high
- value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, 1);
- }
- else
- {
- // Step 14. Reduced search
- // if the move fails high will be re-searched at full depth
- bool doFullDepthSearch = true;
-
- if ( depth >= 3 * ONE_PLY
- && !dangerous
- && !captureOrPromotion
- && !move_is_castle(move))
- {
- ss->reduction = reduction<PV>(depth, i - MultiPV + 2);
- if (ss->reduction)
- {
- assert(newDepth-ss->reduction >= ONE_PLY);
-
- // Reduced depth non-pv search using alpha as upperbound
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, 1);
- doFullDepthSearch = (value > alpha);
- }
- ss->reduction = DEPTH_ZERO; // Restore original reduction
- }
-
- // Step 15. Full depth search
- if (doFullDepthSearch)
- {
- // Full depth non-pv search using alpha as upperbound
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, 1);
-
- // If we are above alpha then research at same depth but as PV
- // to get a correct score or eventually a fail high above beta.
- if (value > alpha)
- value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, 1);
- }
- }
-
- // Step 16. Undo move
- pos.undo_move(move);
-
- // Can we exit fail high loop ?
- if (AbortSearch || value < beta)
- break;
-
- // We are failing high and going to do a research. It's important to update
- // the score before research in case we run out of time while researching.
- ss->bestMove = move;
- rml[i].pv_score = value;
- rml[i].extract_pv_from_tt(pos);
-
- // Inform GUI that PV has changed
- cout << rml[i].pv_info_to_uci(pos, alpha, beta) << endl;
-
- // Prepare for a research after a fail high, each time with a wider window
- beta = Min(beta + AspirationDelta * (1 << researchCountFH), VALUE_INFINITE);
- researchCountFH++;
-
- } // End of fail high loop
-
- // Finished searching the move. If AbortSearch is true, the search
- // was aborted because the user interrupted the search or because we
- // ran out of time. In this case, the return value of the search cannot
- // be trusted, and we break out of the loop without updating the best
- // move and/or PV.
- if (AbortSearch)
- break;
-
- // Remember searched nodes counts for this move
- rml[i].nodes += pos.nodes_searched() - nodes;
-
- assert(value >= -VALUE_INFINITE && value <= VALUE_INFINITE);
- assert(value < beta);
-
- // Step 17. Check for new best move
- if (value <= alpha && i >= MultiPV)
- rml[i].pv_score = -VALUE_INFINITE;
- else
- {
- // PV move or new best move!
-
- // Update PV
- ss->bestMove = move;
- rml[i].pv_score = value;
- rml[i].extract_pv_from_tt(pos);
-
- // We record how often the best move has been changed in each
- // iteration. This information is used for time managment: When
- // the best move changes frequently, we allocate some more time.
- if (MultiPV == 1 && i > 0)
- BestMoveChangesByIteration[Iteration]++;
-
- // Inform GUI that PV has changed, in case of multi-pv UCI protocol
- // requires we send all the PV lines properly sorted.
- rml.sort_multipv(i);
-
- for (int j = 0; j < Min(MultiPV, (int)rml.size()); j++)
- cout << rml[j].pv_info_to_uci(pos, alpha, beta, j) << endl;
-
- // Update alpha. In multi-pv we don't use aspiration window
- if (MultiPV == 1)
- {
- // Raise alpha to setup proper non-pv search upper bound
- if (value > alpha)
- alpha = value;
- }
- else // Set alpha equal to minimum score among the PV lines
- alpha = rml[Min(i, MultiPV - 1)].pv_score;
-
- } // PV move or new best move
-
- assert(alpha >= oldAlpha);
-
- AspirationFailLow = (alpha == oldAlpha);
-
- if (AspirationFailLow && StopOnPonderhit)
- StopOnPonderhit = false;
-
- } // Root moves loop
-
- // Can we exit fail low loop ?
- if (AbortSearch || !AspirationFailLow)
- break;
-
- // Prepare for a research after a fail low, each time with a wider window
- oldAlpha = alpha = Max(alpha - AspirationDelta * (1 << researchCountFL), -VALUE_INFINITE);
- researchCountFL++;
-
- } // Fail low loop
-
- // Sort the moves before to return
- rml.sort();
-
- // Write PV lines to transposition table, in case the relevant entries
- // have been overwritten during the search.
- for (int i = 0; i < MultiPV; i++)
- rml[i].insert_pv_in_tt(pos);
-
- return alpha;
- }
-
-
// search<>() is the main search function for both PV and non-PV nodes and for
// normal and SplitPoint nodes. When called just after a split point the search
// is simpler because we have already probed the hash table, done a null move
// all this work again. We also don't need to store anything to the hash table
// here: This is taken care of after we return from the split point.
- template <NodeType PvNode, bool SpNode>
+ template <NodeType PvNode, bool SpNode, bool Root>
Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) {
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta > alpha && beta <= VALUE_INFINITE);
assert(PvNode || alpha == beta - 1);
- assert(ply > 0 && ply < PLY_MAX);
+ assert((Root || ply > 0) && ply < PLY_MAX);
assert(pos.thread() >= 0 && pos.thread() < ThreadsMgr.active_threads());
Move movesSearched[MOVES_MAX];
+ int64_t nodes;
StateInfo st;
const TTEntry *tte;
Key posKey;
ValueType vt;
Value bestValue, value, oldAlpha;
Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific
- bool isCheck, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous;
+ bool isPvMove, isCheck, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
int moveCount = 0;
int threadID = pos.thread();
SplitPoint* sp = NULL;
+
refinedValue = bestValue = value = -VALUE_INFINITE;
oldAlpha = alpha;
isCheck = pos.is_check();
ss->currentMove = ss->bestMove = threatMove = MOVE_NONE;
(ss+2)->killers[0] = (ss+2)->killers[1] = (ss+2)->mateKiller = MOVE_NONE;
- if (threadID == 0 && ++NodesSincePoll > NodesBetweenPolls)
+ if (!Root)
{
- NodesSincePoll = 0;
- poll(pos);
- }
-
- // Step 2. Check for aborted search and immediate draw
- if ( AbortSearch
- || ThreadsMgr.cutoff_at_splitpoint(threadID)
- || pos.is_draw()
- || ply >= PLY_MAX - 1)
- return VALUE_DRAW;
+ if (threadID == 0 && ++NodesSincePoll > NodesBetweenPolls)
+ {
+ NodesSincePoll = 0;
+ poll(pos);
+ }
- // Step 3. Mate distance pruning
- alpha = Max(value_mated_in(ply), alpha);
- beta = Min(value_mate_in(ply+1), beta);
- if (alpha >= beta)
- return alpha;
+ // Step 2. Check for aborted search and immediate draw
+ if ( StopRequest
+ || ThreadsMgr.cutoff_at_splitpoint(threadID)
+ || pos.is_draw()
+ || ply >= PLY_MAX - 1)
+ return VALUE_DRAW;
+
+ // Step 3. Mate distance pruning
+ alpha = Max(value_mated_in(ply), alpha);
+ beta = Min(value_mate_in(ply+1), beta);
+ if (alpha >= beta)
+ return alpha;
+ }
// Step 4. Transposition table lookup
}
// Save gain for the parent non-capture move
- update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval);
+ if (!Root)
+ update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval);
// Step 6. Razoring (is omitted in PV nodes)
if ( !PvNode
}
// Step 9. Internal iterative deepening
- if ( depth >= IIDDepth[PvNode]
+ if ( !Root
+ && depth >= IIDDepth[PvNode]
&& ttMove == MOVE_NONE
&& (PvNode || (!isCheck && ss->eval >= beta - IIDMargin)))
{
}
// Expensive mate threat detection (only for PV nodes)
- if (PvNode)
+ if (PvNode && !Root) // FIXME
mateThreat = pos.has_mate_threat();
split_point_start: // At split points actual search starts from here
// Initialize a MovePicker object for the current position
- // FIXME currently MovePicker() c'tor is needless called also in SplitPoint
- MovePicker mpBase(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta));
- MovePicker& mp = SpNode ? *sp->mp : mpBase;
+ MovePickerExt<SpNode, Root> mp(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta));
CheckInfo ci(pos);
ss->bestMove = MOVE_NONE;
singleEvasion = !SpNode && isCheck && mp.number_of_evasions() == 1;
futilityBase = ss->eval + ss->evalMargin;
- singularExtensionNode = !SpNode
+ singularExtensionNode = !Root
+ && !SpNode
&& depth >= SingularExtensionDepth[PvNode]
&& tte
&& tte->move()
&& !excludedMove // Do not allow recursive singular extension search
&& (tte->type() & VALUE_TYPE_LOWER)
&& tte->depth() >= depth - 3 * ONE_PLY;
+ if (Root)
+ bestValue = alpha;
+
if (SpNode)
{
lock_grab(&(sp->lock));
else
movesSearched[moveCount++] = move;
+ if (Root)
+ {
+ // This is used by time management
+ FirstRootMove = (moveCount == 1);
+
+ // Save the current node count before the move is searched
+ nodes = pos.nodes_searched();
+
+ // If it's time to send nodes info, do it here where we have the
+ // correct accumulated node counts searched by each thread.
+ if (SendSearchedNodes)
+ {
+ SendSearchedNodes = false;
+ cout << "info nodes " << nodes
+ << " nps " << nps(pos)
+ << " time " << current_search_time() << endl;
+ }
+
+ if (current_search_time() >= 1000)
+ cout << "info currmove " << move
+ << " currmovenumber " << moveCount << endl;
+ }
+
+ isPvMove = (PvNode && moveCount <= (Root ? MultiPV : 1));
moveIsCheck = pos.move_is_check(move, ci);
captureOrPromotion = pos.move_is_capture_or_promotion(move);
// Update current move (this must be done after singular extension search)
ss->currentMove = move;
- newDepth = depth - ONE_PLY + ext;
+ newDepth = depth - (!Root ? ONE_PLY : DEPTH_ZERO) + ext;
// Step 12. Futility pruning (is omitted in PV nodes)
if ( !PvNode
// Step extra. pv search (only in PV nodes)
// The first move in list is the expected PV
- if (PvNode && moveCount == 1)
+ if (isPvMove)
+ {
+ // Aspiration window is disabled in multi-pv case
+ if (Root && MultiPV > 1)
+ alpha = -VALUE_INFINITE;
+
value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, ply+1);
+ }
else
{
// Step 14. Reduced depth search
&& ss->killers[0] != move
&& ss->killers[1] != move)
{
- ss->reduction = reduction<PvNode>(depth, moveCount);
-
+ ss->reduction = Root ? reduction<PvNode>(depth, moveCount - MultiPV + 1)
+ : reduction<PvNode>(depth, moveCount);
if (ss->reduction)
{
alpha = SpNode ? sp->alpha : alpha;
// Step extra. pv search (only in PV nodes)
// Search only for possible new PV nodes, if instead value >= beta then
// parent node fails low with value <= alpha and tries another move.
- if (PvNode && value > alpha && value < beta)
+ if (PvNode && value > alpha && (Root || value < beta))
value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, ply+1);
}
}
alpha = sp->alpha;
}
- if (value > bestValue && !(SpNode && ThreadsMgr.cutoff_at_splitpoint(threadID)))
+ if (!Root && value > bestValue && !(SpNode && ThreadsMgr.cutoff_at_splitpoint(threadID)))
{
bestValue = value;
}
}
+ if (Root)
+ {
+ // Finished searching the move. If StopRequest is true, the search
+ // was aborted because the user interrupted the search or because we
+ // ran out of time. In this case, the return value of the search cannot
+ // be trusted, and we break out of the loop without updating the best
+ // move and/or PV.
+ if (StopRequest)
+ break;
+
+ // Remember searched nodes counts for this move
+ mp.rm->nodes += pos.nodes_searched() - nodes;
+
+ // Step 17. Check for new best move
+ if (!isPvMove && value <= alpha)
+ mp.rm->pv_score = -VALUE_INFINITE;
+ else
+ {
+ // PV move or new best move!
+
+ // Update PV
+ ss->bestMove = move;
+ mp.rm->pv_score = value;
+ mp.rm->extract_pv_from_tt(pos);
+
+ // We record how often the best move has been changed in each
+ // iteration. This information is used for time managment: When
+ // the best move changes frequently, we allocate some more time.
+ if (!isPvMove && MultiPV == 1)
+ BestMoveChangesByIteration[Iteration]++;
+
+ // Inform GUI that PV has changed, in case of multi-pv UCI protocol
+ // requires we send all the PV lines properly sorted.
+ Rml->sort_multipv(moveCount);
+
+ for (int j = 0; j < Min(MultiPV, (int)Rml->size()); j++)
+ cout << (*Rml)[j].pv_info_to_uci(pos, alpha, beta, j) << endl;
+
+ // Update alpha. In multi-pv we don't use aspiration window
+ if (MultiPV == 1)
+ {
+ // Raise alpha to setup proper non-pv search upper bound
+ if (value > alpha)
+ alpha = bestValue = value;
+ }
+ else // Set alpha equal to minimum score among the PV lines
+ alpha = bestValue = (*Rml)[Min(moveCount, MultiPV) - 1].pv_score; // FIXME why moveCount?
+
+ } // PV move or new best move
+ }
+
// Step 18. Check for split
- if ( !SpNode
+ if ( !Root
+ && !SpNode
&& depth >= ThreadsMgr.min_split_depth()
&& ThreadsMgr.active_threads() > 1
&& bestValue < beta
&& ThreadsMgr.available_thread_exists(threadID)
- && !AbortSearch
+ && !StopRequest
&& !ThreadsMgr.cutoff_at_splitpoint(threadID)
&& Iteration <= 99)
ThreadsMgr.split<FakeSplit>(pos, ss, ply, &alpha, beta, &bestValue, depth,
- threatMove, mateThreat, moveCount, &mp, PvNode);
+ threatMove, mateThreat, moveCount, (MovePicker*)&mp, PvNode);
}
// Step 19. Check for mate and stalemate
// Step 20. Update tables
// If the search is not aborted, update the transposition table,
// history counters, and killer moves.
- if (!SpNode && !AbortSearch && !ThreadsMgr.cutoff_at_splitpoint(threadID))
+ if (!SpNode && !StopRequest && !ThreadsMgr.cutoff_at_splitpoint(threadID))
{
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER
&& !pos.move_is_capture_or_promotion(move))
{
update_history(pos, move, depth, movesSearched, moveCount);
- update_killers(move, ss);
+ update_killers(move, ss->killers);
}
}
void update_history(const Position& pos, Move move, Depth depth,
Move movesSearched[], int moveCount) {
Move m;
+ Value bonus = Value(int(depth) * int(depth));
- H.success(pos.piece_on(move_from(move)), move_to(move), depth);
+ H.update(pos.piece_on(move_from(move)), move_to(move), bonus);
for (int i = 0; i < moveCount - 1; i++)
{
assert(m != move);
if (!pos.move_is_capture_or_promotion(m))
- H.failure(pos.piece_on(move_from(m)), move_to(m), depth);
+ H.update(pos.piece_on(move_from(m)), move_to(m), -bonus);
}
}
// update_killers() add a good move that produced a beta-cutoff
// among the killer moves of that ply.
- void update_killers(Move m, SearchStack* ss) {
+ void update_killers(Move m, Move killers[]) {
- if (m == ss->killers[0])
+ if (m == killers[0])
return;
- ss->killers[1] = ss->killers[0];
- ss->killers[0] = m;
+ killers[1] = killers[0];
+ killers[0] = m;
}
&& after != VALUE_NONE
&& pos.captured_piece_type() == PIECE_TYPE_NONE
&& !move_is_special(m))
- H.set_gain(pos.piece_on(move_to(m)), move_to(m), -(before + after));
+ H.update_gain(pos.piece_on(move_to(m)), move_to(m), -(before + after));
}
- // current_search_time() returns the number of milliseconds which have passed
- // since the beginning of the current search.
+ // init_ss_array() does a fast reset of the first entries of a SearchStack
+ // array and of all the excludedMove and skipNullMove entries.
- int current_search_time() {
+ void init_ss_array(SearchStack* ss, int size) {
- return get_system_time() - SearchStartTime;
+ for (int i = 0; i < size; i++, ss++)
+ {
+ ss->excludedMove = MOVE_NONE;
+ ss->skipNullMove = false;
+ ss->reduction = DEPTH_ZERO;
+ ss->sp = NULL;
+
+ if (i < 3)
+ ss->killers[0] = ss->killers[1] = ss->mateKiller = MOVE_NONE;
+ }
}
return s.str();
}
- // nps() computes the current nodes/second count.
+
+ // current_search_time() returns the number of milliseconds which have passed
+ // since the beginning of the current search.
+
+ int current_search_time() {
+
+ return get_system_time() - SearchStartTime;
+ }
+
+
+ // nps() computes the current nodes/second count
int nps(const Position& pos) {
int t = current_search_time();
// Poll for input
- if (data_available())
+ if (input_available())
{
// We are line oriented, don't read single chars
std::string command;
if (command == "quit")
{
- AbortSearch = true;
- PonderSearch = false;
- Quit = true;
+ // Quit the program as soon as possible
+ Pondering = false;
+ QuitRequest = StopRequest = true;
return;
}
else if (command == "stop")
{
- AbortSearch = true;
- PonderSearch = false;
+ // Stop calculating as soon as possible, but still send the "bestmove"
+ // and possibly the "ponder" token when finishing the search.
+ Pondering = false;
+ StopRequest = true;
}
else if (command == "ponderhit")
- ponderhit();
+ {
+ // The opponent has played the expected move. GUI sends "ponderhit" if
+ // we were told to ponder on the same move the opponent has played. We
+ // should continue searching but switching from pondering to normal search.
+ Pondering = false;
+
+ if (StopOnPonderhit)
+ StopRequest = true;
+ }
}
// Print search information
if (dbg_show_hit_rate)
dbg_print_hit_rate();
- cout << "info nodes " << pos.nodes_searched() << " nps " << nps(pos)
- << " time " << t << endl;
+ // Send info on searched nodes as soon as we return to root
+ SendSearchedNodes = true;
}
// Should we stop the search?
- if (PonderSearch)
+ if (Pondering)
return;
bool stillAtFirstMove = FirstRootMove
bool noMoreTime = t > TimeMgr.maximum_time()
|| stillAtFirstMove;
- if ( (Iteration >= 3 && UseTimeManagement && noMoreTime)
+ if ( (UseTimeManagement && noMoreTime)
|| (ExactMaxTime && t >= ExactMaxTime)
- || (Iteration >= 3 && MaxNodes && pos.nodes_searched() >= MaxNodes))
- AbortSearch = true;
- }
-
-
- // ponderhit() is called when the program is pondering (i.e. thinking while
- // it's the opponent's turn to move) in order to let the engine know that
- // it correctly predicted the opponent's move.
-
- void ponderhit() {
-
- int t = current_search_time();
- PonderSearch = false;
-
- bool stillAtFirstMove = FirstRootMove
- && !AspirationFailLow
- && t > TimeMgr.available_time();
-
- bool noMoreTime = t > TimeMgr.maximum_time()
- || stillAtFirstMove;
-
- if (Iteration >= 3 && UseTimeManagement && (noMoreTime || StopOnPonderhit))
- AbortSearch = true;
- }
-
-
- // init_ss_array() does a fast reset of the first entries of a SearchStack
- // array and of all the excludedMove and skipNullMove entries.
-
- void init_ss_array(SearchStack* ss, int size) {
-
- for (int i = 0; i < size; i++, ss++)
- {
- ss->excludedMove = MOVE_NONE;
- ss->skipNullMove = false;
- ss->reduction = DEPTH_ZERO;
- ss->sp = NULL;
-
- if (i < 3)
- ss->killers[0] = ss->killers[1] = ss->mateKiller = MOVE_NONE;
- }
+ || (MaxNodes && pos.nodes_searched() >= MaxNodes)) // FIXME
+ StopRequest = true;
}
// the UCI protocol: When pondering, the engine is not allowed to give a
// "bestmove" before the GUI sends it a "stop" or "ponderhit" command.
// We simply wait here until one of these commands is sent, and return,
- // after which the bestmove and pondermove will be printed (in id_loop()).
+ // after which the bestmove and pondermove will be printed.
void wait_for_stop_or_ponderhit() {
while (true)
{
+ // Wait for a command from stdin
if (!std::getline(std::cin, command))
command = "quit";
if (command == "quit")
{
- Quit = true;
+ QuitRequest = true;
break;
}
else if (command == "ponderhit" || command == "stop")
ss->sp = tsp;
if (tsp->pvNode)
- search<PV, true>(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply);
+ search<PV, true, false>(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply);
else
- search<NonPV, true>(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply);
+ search<NonPV, true, false>(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply);
assert(threads[threadID].state == THREAD_SEARCHING);
// formatted according to UCI specification and eventually writes the info
// to a log file. It is called at each iteration or after a new pv is found.
- std::string RootMove::pv_info_to_uci(const Position& pos, Value alpha, Value beta, int pvLine) {
+ std::string RootMove::pv_info_to_uci(Position& pos, Value alpha, Value beta, int pvLine) {
std::stringstream s, l;
Move* m = pv;
ss[0].eval = ss[0].evalMargin = VALUE_NONE;
// Generate all legal moves
- MoveStack* last = generate_moves(pos, mlist);
+ MoveStack* last = generate<MV_LEGAL>(pos, mlist);
// Add each move to the RootMoveList's vector
for (MoveStack* cur = mlist; cur != last; cur++)
// This is the second order score that is used to compare the moves when
// the first order pv scores of both moves are equal.
- void RootMoveList::set_non_pv_scores(const Position& pos)
+ void RootMoveList::set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss)
{
Move move;
Value score = VALUE_ZERO;
- MovePicker mp(pos, MOVE_NONE, ONE_PLY, H);
+ MovePicker mp(pos, ttm, ONE_PLY, H, ss);
while ((move = mp.get_next_move()) != MOVE_NONE)
for (Base::iterator it = begin(); it != end(); ++it)
projects / stockfish / blobdiff