////
#include <cassert>
+#include <cmath>
#include <cstring>
#include <fstream>
#include <iostream>
/// Types
- // IterationInfoType stores search results for each iteration
- //
- // Because we use relatively small (dynamic) aspiration window,
- // there happens many fail highs and fail lows in root. And
- // because we don't do researches in those cases, "value" stored
- // here is not necessarily exact. Instead in case of fail high/low
- // we guess what the right value might be and store our guess
- // as a "speculated value" and then move on. Speculated values are
- // used just to calculate aspiration window width, so also if are
- // not exact is not big a problem.
- struct IterationInfoType {
+ // ThreadsManager class is used to handle all the threads related stuff in search,
+ // init, starting, parking and, the most important, launching a slave thread at a
+ // split point are what this class does. All the access to shared thread data is
+ // done through this class, so that we avoid using global variables instead.
- IterationInfoType(Value v = Value(0), Value sv = Value(0))
- : value(v), speculatedValue(sv) {}
+ class ThreadsManager {
+ /* As long as the single ThreadsManager object is defined as a global we don't
+ need to explicitly initialize to zero its data members because variables with
+ static storage duration are automatically set to zero before enter main()
+ */
+ public:
+ void init_threads();
+ void exit_threads();
+
+ int active_threads() const { return ActiveThreads; }
+ void set_active_threads(int newActiveThreads) { ActiveThreads = newActiveThreads; }
+ void incrementNodeCounter(int threadID) { threads[threadID].nodes++; }
+ void incrementBetaCounter(Color us, Depth d, int threadID) { threads[threadID].betaCutOffs[us] += unsigned(d); }
+ void print_current_line(SearchStack ss[], int ply, int threadID);
+
+ void resetNodeCounters();
+ void resetBetaCounters();
+ int64_t nodes_searched() const;
+ void get_beta_counters(Color us, int64_t& our, int64_t& their) const;
+ bool available_thread_exists(int master) const;
+ bool thread_is_available(int slave, int master) const;
+ bool thread_should_stop(int threadID) const;
+ void wake_sleeping_threads();
+ void put_threads_to_sleep();
+ void idle_loop(int threadID, SplitPoint* waitSp);
+ bool split(const Position& pos, SearchStack* ss, int ply, Value* alpha, Value* beta, Value* bestValue,
+ const Value futilityValue, Depth depth, int* moves, MovePicker* mp, int master, bool pvNode);
- Value value, speculatedValue;
- };
+ private:
+ friend void poll();
+ int ActiveThreads;
+ volatile bool AllThreadsShouldExit, AllThreadsShouldSleep;
+ Thread threads[MAX_THREADS];
+ SplitPoint SplitPointStack[MAX_THREADS][ACTIVE_SPLIT_POINTS_MAX];
- // The BetaCounterType class is used to order moves at ply one.
- // Apart for the first one that has its score, following moves
- // normally have score -VALUE_INFINITE, so are ordered according
- // to the number of beta cutoffs occurred under their subtree during
- // the last iteration. The counters are per thread variables to avoid
- // concurrent accessing under SMP case.
+ Lock MPLock, IOLock;
- struct BetaCounterType {
+#if !defined(_MSC_VER)
+ pthread_cond_t WaitCond;
+ pthread_mutex_t WaitLock;
+#else
+ HANDLE SitIdleEvent[MAX_THREADS];
+#endif
- BetaCounterType();
- void clear();
- void add(Color us, Depth d, int threadID);
- void read(Color us, int64_t& our, int64_t& their);
};
- // The RootMove class is used for moves at the root at the tree. For each
+ // RootMove struct is used for moves at the root at the tree. For each
// root move, we store a score, a node count, and a PV (really a refutation
// in the case of moves which fail low).
// Search depth at iteration 1
const Depth InitialDepth = OnePly;
- // Depth limit for selective search
- const Depth SelectiveDepth = 7 * OnePly;
-
// Use internal iterative deepening?
const bool UseIIDAtPVNodes = true;
const bool UseIIDAtNonPVNodes = true;
// better than the second best move.
const Value EasyMoveMargin = Value(0x200);
- // Problem margin. If the score of the first move at iteration N+1 has
- // dropped by more than this since iteration N, the boolean variable
- // "Problem" is set to true, which will make the program spend some extra
- // time looking for a better move.
- const Value ProblemMargin = Value(0x28);
-
- // No problem margin. If the boolean "Problem" is true, and a new move
- // is found at the root which is less than NoProblemMargin worse than the
- // best move from the previous iteration, Problem is set back to false.
- const Value NoProblemMargin = Value(0x14);
-
// Null move margin. A null move search will not be done if the static
// evaluation of the position is more than NullMoveMargin below beta.
const Value NullMoveMargin = Value(0x200);
// remaining ones we will extend it.
const Value SingleReplyMargin = Value(0x20);
- // Margins for futility pruning in the quiescence search, and at frontier
- // and near frontier nodes.
- const Value FutilityMarginQS = Value(0x80);
-
- // Each move futility margin is decreased
- const Value IncrementalFutilityMargin = Value(0x8);
-
// Depth limit for razoring
const Depth RazorDepth = 4 * OnePly;
- /// Variables initialized by UCI options
+ /// Lookup tables initialized at startup
+
+ // Reduction lookup tables and their getter functions
+ int8_t PVReductionMatrix[64][64]; // [depth][moveNumber]
+ int8_t NonPVReductionMatrix[64][64]; // [depth][moveNumber]
+
+ inline Depth pv_reduction(Depth d, int mn) { return (Depth) PVReductionMatrix[Min(d / 2, 63)][Min(mn, 63)]; }
+ inline Depth nonpv_reduction(Depth d, int mn) { return (Depth) NonPVReductionMatrix[Min(d / 2, 63)][Min(mn, 63)]; }
+
+ // Futility lookup tables and their getter functions
+ const Value FutilityMarginQS = Value(0x80);
+ int32_t FutilityMarginsMatrix[14][64]; // [depth][moveNumber]
+ int FutilityMoveCountArray[32]; // [depth]
+
+ inline Value futility_margin(Depth d, int mn) { return Value(d < 7*OnePly ? FutilityMarginsMatrix[Max(d, 0)][Min(mn, 63)] : 2 * VALUE_INFINITE); }
+ inline int futility_move_count(Depth d) { return d < 16*OnePly ? FutilityMoveCountArray[d] : 512; }
- // Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV nodes
- int LMRPVMoves, LMRNonPVMoves;
+ /// Variables initialized by UCI options
// Depth limit for use of dynamic threat detection
Depth ThreatDepth;
// Iteration counters
int Iteration;
- BetaCounterType BetaCounter;
// Scores and number of times the best move changed for each iteration
- IterationInfoType IterationInfo[PLY_MAX_PLUS_2];
+ Value ValueByIteration[PLY_MAX_PLUS_2];
int BestMoveChangesByIteration[PLY_MAX_PLUS_2];
+ // Search window management
+ int AspirationDelta;
+
// MultiPV mode
int MultiPV;
int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime, ExactMaxTime;
bool UseTimeManagement, InfiniteSearch, PonderSearch, StopOnPonderhit;
bool AbortSearch, Quit;
- bool FailHigh, FailLow, Problem;
+ bool AspirationFailLow;
// Show current line?
bool ShowCurrentLine;
std::ofstream LogFile;
// MP related variables
- int ActiveThreads = 1;
Depth MinimumSplitDepth;
int MaxThreadsPerSplitPoint;
- Thread Threads[THREAD_MAX];
- Lock MPLock;
- Lock IOLock;
- bool AllThreadsShouldExit = false;
- SplitPoint SplitPointStack[THREAD_MAX][ACTIVE_SPLIT_POINTS_MAX];
- bool Idle = true;
-
-#if !defined(_MSC_VER)
- pthread_cond_t WaitCond;
- pthread_mutex_t WaitLock;
-#else
- HANDLE SitIdleEvent[THREAD_MAX];
-#endif
+ ThreadsManager TM;
// Node counters, used only by thread[0] but try to keep in different
// cache lines (64 bytes each) from the heavy SMP read accessed variables.
// History table
History H;
-
/// Functions
Value id_loop(const Position& pos, Move searchMoves[]);
- Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value alpha, Value beta);
+ Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta);
Value search_pv(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
Value search(Position& pos, SearchStack ss[], Value beta, Depth depth, int ply, bool allowNullmove, int threadID, Move excludedMove = MOVE_NONE);
Value qsearch(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
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_gains(const Position& pos, Move move, Value before, Value after);
- bool fail_high_ply_1();
int current_search_time();
int nps();
void poll();
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();
- void destroy_split_point_stack();
- bool thread_should_stop(int threadID);
- bool thread_is_available(int slave, int master);
- bool idle_thread_exists(int master);
- bool split(const Position& pos, SearchStack* ss, int ply,
- Value *alpha, Value *beta, Value *bestValue,
- const Value futilityValue, Depth depth, int *moves,
- MovePicker *mp, int master, bool pvNode);
- void wake_sleeping_threads();
-
#if !defined(_MSC_VER)
void *init_thread(void *threadID);
#else
//// Functions
////
-//FIXME: HACK
-static double lnArray[512];
+/// init_threads(), exit_threads() and nodes_searched() are helpers to
+/// give accessibility to some TM methods from outside of current file.
+
+void init_threads() { TM.init_threads(); }
+void exit_threads() { TM.exit_threads(); }
+int64_t nodes_searched() { return TM.nodes_searched(); }
-inline double ln(int i)
-{
- return lnArray[i];
-}
/// 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 maxNodes, int maxTime, Move searchMoves[]) {
// Initialize global search variables
- Idle = StopOnPonderhit = AbortSearch = Quit = false;
- FailHigh = FailLow = Problem = false;
+ StopOnPonderhit = AbortSearch = Quit = false;
+ AspirationFailLow = false;
NodesSincePoll = 0;
SearchStartTime = get_system_time();
ExactMaxTime = maxTime;
UseTimeManagement = !ExactMaxTime && !MaxDepth && !MaxNodes && !InfiniteSearch;
// Look for a book move, only during games, not tests
- if (UseTimeManagement && !ponder && get_option_value_bool("OwnBook"))
+ if (UseTimeManagement && get_option_value_bool("OwnBook"))
{
Move bookMove;
if (get_option_value_string("Book File") != OpeningBook.file_name())
bookMove = OpeningBook.get_move(pos);
if (bookMove != MOVE_NONE)
{
+ if (PonderSearch)
+ wait_for_stop_or_ponderhit();
+
cout << "bestmove " << bookMove << endl;
return true;
}
}
- for (int i = 0; i < THREAD_MAX; i++)
- {
- Threads[i].nodes = 0ULL;
- Threads[i].failHighPly1 = false;
- }
+ TM.resetNodeCounters();
if (button_was_pressed("New Game"))
loseOnTime = false; // Reset at the beginning of a new game
MateThreatExtension[1] = Depth(get_option_value_int("Mate Threat Extension (PV nodes)"));
MateThreatExtension[0] = Depth(get_option_value_int("Mate Threat Extension (non-PV nodes)"));
- LMRPVMoves = get_option_value_int("Full Depth Moves (PV nodes)") + 1;
- LMRNonPVMoves = get_option_value_int("Full Depth Moves (non-PV nodes)") + 1;
ThreatDepth = get_option_value_int("Threat Depth") * OnePly;
Chess960 = get_option_value_bool("UCI_Chess960");
// Set the number of active threads
int newActiveThreads = get_option_value_int("Threads");
- if (newActiveThreads != ActiveThreads)
+ if (newActiveThreads != TM.active_threads())
{
- ActiveThreads = newActiveThreads;
- init_eval(ActiveThreads);
+ TM.set_active_threads(newActiveThreads);
+ init_eval(TM.active_threads());
+ // HACK: init_eval() destroys the static castleRightsMask[] array in the
+ // Position class. The below line repairs the damage.
+ Position p(pos.to_fen());
+ assert(pos.is_ok());
}
// Wake up sleeping threads
- wake_sleeping_threads();
+ TM.wake_sleeping_threads();
- for (int i = 1; i < ActiveThreads; i++)
- assert(thread_is_available(i, 0));
+ for (int i = 1; i < TM.active_threads(); i++)
+ assert(TM.thread_is_available(i, 0));
// Set thinking time
int myTime = time[side_to_move];
// We're ready to start thinking. Call the iterative deepening loop function
Value v = id_loop(pos, searchMoves);
-
if (UseLSNFiltering)
{
// Step 1. If this is sudden death game and our position is hopeless,
if (UseLogFile)
LogFile.close();
- Idle = true;
- return !Quit;
-}
-
-
-/// init_threads() is called during startup. It launches all helper threads,
-/// and initializes the split point stack and the global locks and condition
-/// objects.
-
-#include <cmath> //FIXME: HACK
-
-void init_threads() {
-
- // FIXME: HACK!!
- for (int i = 0; i < 512; i++)
- lnArray[i] = log(double(i));
-
- volatile int i;
-
-#if !defined(_MSC_VER)
- pthread_t pthread[1];
-#endif
-
- for (i = 0; i < THREAD_MAX; i++)
- Threads[i].activeSplitPoints = 0;
-
- // Initialize global locks
- lock_init(&MPLock, NULL);
- lock_init(&IOLock, NULL);
-
- init_split_point_stack();
-
-#if !defined(_MSC_VER)
- pthread_mutex_init(&WaitLock, NULL);
- pthread_cond_init(&WaitCond, NULL);
-#else
- for (i = 0; i < THREAD_MAX; i++)
- SitIdleEvent[i] = CreateEvent(0, FALSE, FALSE, 0);
-#endif
-
- // All threads except the main thread should be initialized to idle state
- for (i = 1; i < THREAD_MAX; i++)
- {
- Threads[i].stop = false;
- Threads[i].workIsWaiting = false;
- Threads[i].idle = true;
- Threads[i].running = false;
- }
-
- // Launch the helper threads
- for (i = 1; i < THREAD_MAX; i++)
- {
-#if !defined(_MSC_VER)
- pthread_create(pthread, NULL, init_thread, (void*)(&i));
-#else
- DWORD iID[1];
- CreateThread(NULL, 0, init_thread, (LPVOID)(&i), 0, iID);
-#endif
+ TM.put_threads_to_sleep();
- // Wait until the thread has finished launching
- while (!Threads[i].running);
- }
+ return !Quit;
}
-/// stop_threads() is called when the program exits. It makes all the
-/// helper threads exit cleanly.
-
-void stop_threads() {
-
- ActiveThreads = THREAD_MAX; // HACK
- Idle = false; // HACK
- wake_sleeping_threads();
- AllThreadsShouldExit = true;
- for (int i = 1; i < THREAD_MAX; i++)
- {
- Threads[i].stop = true;
- while (Threads[i].running);
- }
- destroy_split_point_stack();
-}
+/// init_search() is called during startup. It initializes various lookup tables
+void init_search() {
-/// nodes_searched() returns the total number of nodes searched so far in
-/// the current search.
+ // Init our reduction lookup tables
+ for (int i = 1; i < 64; i++) // i == depth (OnePly = 1)
+ for (int j = 1; j < 64; j++) // j == moveNumber
+ {
+ double pvRed = 0.5 + log(double(i)) * log(double(j)) / 6.0;
+ double nonPVRed = 0.5 + log(double(i)) * log(double(j)) / 3.0;
+ PVReductionMatrix[i][j] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(OnePly)) : 0);
+ NonPVReductionMatrix[i][j] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(OnePly)) : 0);
+ }
-int64_t nodes_searched() {
+ // Init futility margins array
+ for (int i = 0; i < 14; i++) // i == depth (OnePly = 2)
+ for (int j = 0; j < 64; j++) // j == moveNumber
+ {
+ FutilityMarginsMatrix[i][j] = (i < 2 ? 0 : 112 * bitScanReverse32(i * i / 2)) - 8 * j; // FIXME: test using log instead of BSR
+ }
- int64_t result = 0ULL;
- for (int i = 0; i < ActiveThreads; i++)
- result += Threads[i].nodes;
- return result;
+ // Init futility move count array
+ for (int i = 0; i < 32; i++) // i == depth (OnePly = 2)
+ FutilityMoveCountArray[i] = 3 + (1 << (3 * i / 8));
}
// searchMoves are verified, copied, scored and sorted
RootMoveList rml(p, searchMoves);
+ // Handle special case of searching on a mate/stale position
if (rml.move_count() == 0)
{
if (PonderSearch)
cout << "info depth " << 1 << "\ninfo depth " << 1
<< " score " << value_to_string(rml.get_move_score(0))
<< " time " << current_search_time()
- << " nodes " << nodes_searched()
+ << " nodes " << TM.nodes_searched()
<< " nps " << nps()
<< " pv " << rml.get_move(0) << "\n";
TT.new_search();
H.clear();
init_ss_array(ss);
- IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0));
+ ValueByIteration[1] = rml.get_move_score(0);
Iteration = 1;
// Is one move significantly better than others after initial scoring ?
// Calculate dynamic search window based on previous iterations
Value alpha, beta;
- if (MultiPV == 1 && Iteration >= 6 && abs(IterationInfo[Iteration - 1].value) < VALUE_KNOWN_WIN)
+ if (MultiPV == 1 && Iteration >= 6 && abs(ValueByIteration[Iteration - 1]) < VALUE_KNOWN_WIN)
{
- int prevDelta1 = IterationInfo[Iteration - 1].speculatedValue - IterationInfo[Iteration - 2].speculatedValue;
- int prevDelta2 = IterationInfo[Iteration - 2].speculatedValue - IterationInfo[Iteration - 3].speculatedValue;
+ int prevDelta1 = ValueByIteration[Iteration - 1] - ValueByIteration[Iteration - 2];
+ int prevDelta2 = ValueByIteration[Iteration - 2] - ValueByIteration[Iteration - 3];
- int delta = Max(2 * abs(prevDelta1) + abs(prevDelta2), ProblemMargin);
+ AspirationDelta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16);
+ AspirationDelta = (AspirationDelta + 7) / 8 * 8; // Round to match grainSize
- alpha = Max(IterationInfo[Iteration - 1].value - delta, -VALUE_INFINITE);
- beta = Min(IterationInfo[Iteration - 1].value + delta, VALUE_INFINITE);
+ alpha = Max(ValueByIteration[Iteration - 1] - AspirationDelta, -VALUE_INFINITE);
+ beta = Min(ValueByIteration[Iteration - 1] + AspirationDelta, VALUE_INFINITE);
}
else
{
break; // Value cannot be trusted. Break out immediately!
//Save info about search result
- Value speculatedValue;
- bool fHigh = false;
- bool fLow = false;
- Value delta = value - IterationInfo[Iteration - 1].value;
-
- if (value >= beta)
- {
- assert(delta > 0);
-
- fHigh = true;
- speculatedValue = value + delta;
- BestMoveChangesByIteration[Iteration] += 2; // Allocate more time
- }
- else if (value <= alpha)
- {
- assert(value == alpha);
- assert(delta < 0);
-
- fLow = true;
- speculatedValue = value + delta;
- BestMoveChangesByIteration[Iteration] += 3; // Allocate more time
- } else
- speculatedValue = value;
-
- speculatedValue = Min(Max(speculatedValue, -VALUE_INFINITE), VALUE_INFINITE);
- IterationInfo[Iteration] = IterationInfoType(value, speculatedValue);
+ ValueByIteration[Iteration] = value;
// Drop the easy move if it differs from the new best move
if (ss[0].pv[0] != EasyMove)
EasyMove = MOVE_NONE;
- Problem = false;
-
if (UseTimeManagement)
{
// Time to stop?
// Stop search early when the last two iterations returned a mate score
if ( Iteration >= 6
- && abs(IterationInfo[Iteration].value) >= abs(VALUE_MATE) - 100
- && abs(IterationInfo[Iteration-1].value) >= abs(VALUE_MATE) - 100)
+ && abs(ValueByIteration[Iteration]) >= abs(VALUE_MATE) - 100
+ && abs(ValueByIteration[Iteration-1]) >= abs(VALUE_MATE) - 100)
stopSearch = true;
// Stop search early if one move seems to be much better than the rest
- int64_t nodes = nodes_searched();
+ int64_t nodes = TM.nodes_searched();
if ( Iteration >= 8
- && !fLow
- && !fHigh
&& EasyMove == ss[0].pv[0]
&& ( ( rml.get_move_cumulative_nodes(0) > (nodes * 85) / 100
&& current_search_time() > MaxSearchTime / 16)
wait_for_stop_or_ponderhit();
else
// Print final search statistics
- cout << "info nodes " << nodes_searched()
+ cout << "info nodes " << TM.nodes_searched()
<< " nps " << nps()
<< " time " << current_search_time()
<< " hashfull " << TT.full() << endl;
if (dbg_show_hit_rate)
dbg_print_hit_rate(LogFile);
- LogFile << "\nNodes: " << nodes_searched()
+ LogFile << "\nNodes: " << TM.nodes_searched()
<< "\nNodes/second: " << nps()
<< "\nBest move: " << move_to_san(p, ss[0].pv[0]);
// similar to search_pv except that it uses a different move ordering
// scheme and prints some information to the standard output.
- Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value alpha, Value beta) {
+ Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta) {
- Value oldAlpha = alpha;
+ int64_t nodes;
+ Move move;
+ StateInfo st;
+ Depth depth, ext, newDepth;
Value value;
CheckInfo ci(pos);
+ int researchCount = 0;
+ bool moveIsCheck, captureOrPromotion, dangerous;
+ Value alpha = oldAlpha;
+ bool isCheck = pos.is_check();
+
+ // Evaluate the position statically
+ EvalInfo ei;
+ ss[0].eval = !isCheck ? evaluate(pos, ei, 0) : VALUE_NONE;
- // Loop through all the moves in the root move list
- for (int i = 0; i < rml.move_count() && !AbortSearch; i++)
+ while (1) // Fail low loop
{
- if (alpha >= beta)
- {
- // We failed high, invalidate and skip next moves, leave node-counters
- // and beta-counters as they are and quickly return, we will try to do
- // a research at the next iteration with a bigger aspiration window.
- rml.set_move_score(i, -VALUE_INFINITE);
- continue;
- }
- int64_t nodes;
- Move move;
- StateInfo st;
- Depth depth, ext, newDepth;
- RootMoveNumber = i + 1;
- FailHigh = false;
+ // Loop through all the moves in the root move list
+ for (int i = 0; i < rml.move_count() && !AbortSearch; i++)
+ {
+ if (alpha >= beta)
+ {
+ // We failed high, invalidate and skip next moves, leave node-counters
+ // and beta-counters as they are and quickly return, we will try to do
+ // a research at the next iteration with a bigger aspiration window.
+ rml.set_move_score(i, -VALUE_INFINITE);
+ continue;
+ }
- // Save the current node count before the move is searched
- nodes = nodes_searched();
+ RootMoveNumber = i + 1;
- // Reset beta cut-off counters
- BetaCounter.clear();
+ // Save the current node count before the move is searched
+ nodes = TM.nodes_searched();
- // Pick the next root move, and print the move and the move number to
- // the standard output.
- move = ss[0].currentMove = rml.get_move(i);
+ // Reset beta cut-off counters
+ TM.resetBetaCounters();
- if (current_search_time() >= 1000)
- cout << "info currmove " << move
- << " currmovenumber " << RootMoveNumber << endl;
+ // Pick the next root move, and print the move and the move number to
+ // the standard output.
+ move = ss[0].currentMove = rml.get_move(i);
- // Decide search depth for this move
- bool moveIsCheck = pos.move_is_check(move);
- bool captureOrPromotion = pos.move_is_capture_or_promotion(move);
- bool dangerous;
- depth = (Iteration - 2) * OnePly + InitialDepth;
- ext = extension(pos, move, true, captureOrPromotion, moveIsCheck, false, false, &dangerous);
- newDepth = depth + ext;
+ if (current_search_time() >= 1000)
+ cout << "info currmove " << move
+ << " currmovenumber " << RootMoveNumber << endl;
- // Make the move, and search it
- pos.do_move(move, st, ci, moveIsCheck);
+ // Decide search depth for this move
+ moveIsCheck = pos.move_is_check(move);
+ captureOrPromotion = pos.move_is_capture_or_promotion(move);
+ depth = (Iteration - 2) * OnePly + InitialDepth;
+ ext = extension(pos, move, true, captureOrPromotion, moveIsCheck, false, false, &dangerous);
+ newDepth = depth + ext;
- if (i < MultiPV)
- {
- // Aspiration window is disabled in multi-pv case
- if (MultiPV > 1)
- alpha = -VALUE_INFINITE;
+ value = - VALUE_INFINITE;
- value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0);
+ while (1) // Fail high loop
+ {
- // If the value has dropped a lot compared to the last iteration,
- // set the boolean variable Problem to true. This variable is used
- // for time managment: When Problem is true, we try to complete the
- // current iteration before playing a move.
- Problem = ( Iteration >= 2
- && value <= IterationInfo[Iteration - 1].value - ProblemMargin);
+ // Make the move, and search it
+ pos.do_move(move, st, ci, moveIsCheck);
- if (Problem && StopOnPonderhit)
- StopOnPonderhit = false;
- }
- else
- {
- // 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 >= 3*OnePly // FIXME was newDepth
- && !dangerous
- && !captureOrPromotion
- && !move_is_castle(move))
- {
- double red = 0.5 + ln(RootMoveNumber - MultiPV + 1) * ln(depth / 2) / 6.0;
- if (red >= 1.0)
+ if (i < MultiPV || value > alpha)
{
- ss[0].reduction = Depth(int(floor(red * int(OnePly))));
- value = -search(pos, ss, -alpha, newDepth-ss[0].reduction, 1, true, 0);
+ // Aspiration window is disabled in multi-pv case
+ if (MultiPV > 1)
+ alpha = -VALUE_INFINITE;
+
+ value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0);
}
else
- value = alpha + 1; // Just to trigger next condition
- } else
- value = alpha + 1; // Just to trigger next condition
-
- if (value > alpha)
- {
- 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 using a PV search. 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);
+ // 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.
+ bool doFullDepthSearch = true;
+
+ if ( depth >= 3*OnePly // FIXME was newDepth
+ && !dangerous
+ && !captureOrPromotion
+ && !move_is_castle(move))
+ {
+ ss[0].reduction = pv_reduction(depth, RootMoveNumber - MultiPV + 1);
+ if (ss[0].reduction)
+ {
+ value = -search(pos, ss, -alpha, newDepth-ss[0].reduction, 1, true, 0);
+ doFullDepthSearch = (value > alpha);
+ }
+ }
+
+ if (doFullDepthSearch)
+ {
+ ss[0].reduction = Depth(0);
+ value = -search(pos, ss, -alpha, newDepth, 1, true, 0);
+
+ if (value > alpha)
+ value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0);
+ }
}
- }
- }
-
- pos.undo_move(move);
-
- // 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 beta-cutoff and searched nodes counts for this move. The
- // info is used to sort the root moves at the next iteration.
- int64_t our, their;
- BetaCounter.read(pos.side_to_move(), our, their);
- rml.set_beta_counters(i, our, their);
- rml.set_move_nodes(i, nodes_searched() - nodes);
+ pos.undo_move(move);
- assert(value >= -VALUE_INFINITE && value <= VALUE_INFINITE);
-
- if (value <= alpha && i >= MultiPV)
- rml.set_move_score(i, -VALUE_INFINITE);
- else
- {
- // PV move or new best move!
-
- // 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);
+ // Can we exit fail high loop ?
+ if (AbortSearch || value < beta)
+ break;
- if (MultiPV == 1)
- {
- // 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 (i > 0)
- BestMoveChangesByIteration[Iteration]++;
+ // We are failing high and going to do a research. It's important to update score
+ // before research in case we run out of time while researching.
+ 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);
// Print search information to the standard output
cout << "info depth " << Iteration
<< ((value >= beta) ? " lowerbound" :
((value <= alpha)? " upperbound" : ""))
<< " time " << current_search_time()
- << " nodes " << nodes_searched()
+ << " nodes " << TM.nodes_searched()
<< " nps " << nps()
<< " pv ";
: (value <= alpha ? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT));
LogFile << pretty_pv(pos, current_search_time(), Iteration,
- nodes_searched(), value, type, ss[0].pv) << endl;
+ TM.nodes_searched(), value, type, ss[0].pv) << endl;
}
- if (value > alpha)
- alpha = value;
- // Reset the global variable Problem to false if the value isn't too
- // far below the final value from the last iteration.
- if (value > IterationInfo[Iteration - 1].value - NoProblemMargin)
- Problem = false;
- }
- else // MultiPV > 1
+ // Prepare for a research after a fail high, each time with a wider window
+ researchCount++;
+ beta = Min(beta + AspirationDelta * (1 << researchCount), VALUE_INFINITE);
+
+ } // 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 beta-cutoff and searched nodes counts for this move. The
+ // info is used to sort the root moves at the next iteration.
+ int64_t our, their;
+ TM.get_beta_counters(pos.side_to_move(), our, their);
+ rml.set_beta_counters(i, our, their);
+ rml.set_move_nodes(i, TM.nodes_searched() - nodes);
+
+ assert(value >= -VALUE_INFINITE && value <= VALUE_INFINITE);
+
+ if (value <= alpha && i >= MultiPV)
+ rml.set_move_score(i, -VALUE_INFINITE);
+ else
{
- rml.sort_multipv(i);
- for (int j = 0; j < Min(MultiPV, rml.move_count()); j++)
+ // PV move or new best move!
+
+ // 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)
{
- cout << "info multipv " << j + 1
- << " score " << value_to_string(rml.get_move_score(j))
- << " depth " << ((j <= i)? Iteration : Iteration - 1)
- << " time " << current_search_time()
- << " nodes " << nodes_searched()
- << " nps " << nps()
+ // 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 (i > 0)
+ BestMoveChangesByIteration[Iteration]++;
+
+ // Print search information to the standard output
+ cout << "info depth " << Iteration
+ << " score " << value_to_string(value)
+ << ((value >= beta) ? " lowerbound" :
+ ((value <= alpha)? " upperbound" : ""))
+ << " time " << current_search_time()
+ << " nodes " << TM.nodes_searched()
+ << " nps " << nps()
<< " pv ";
- for (int k = 0; rml.get_move_pv(j, k) != MOVE_NONE && k < PLY_MAX; k++)
- cout << rml.get_move_pv(j, k) << " ";
+ for (int j = 0; ss[0].pv[j] != MOVE_NONE && j < PLY_MAX; j++)
+ cout << ss[0].pv[j] << " ";
cout << endl;
+
+ if (UseLogFile)
+ {
+ ValueType type = (value >= beta ? VALUE_TYPE_LOWER
+ : (value <= alpha ? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT));
+
+ LogFile << pretty_pv(pos, current_search_time(), Iteration,
+ TM.nodes_searched(), value, type, ss[0].pv) << endl;
+ }
+ if (value > alpha)
+ alpha = value;
}
- alpha = rml.get_move_score(Min(i, MultiPV-1));
- }
- } // PV move or new best move
+ else // MultiPV > 1
+ {
+ rml.sort_multipv(i);
+ for (int j = 0; j < Min(MultiPV, rml.move_count()); j++)
+ {
+ cout << "info multipv " << j + 1
+ << " score " << value_to_string(rml.get_move_score(j))
+ << " depth " << ((j <= i)? Iteration : Iteration - 1)
+ << " time " << current_search_time()
+ << " nodes " << TM.nodes_searched()
+ << " nps " << nps()
+ << " pv ";
+
+ for (int k = 0; rml.get_move_pv(j, k) != MOVE_NONE && k < PLY_MAX; k++)
+ cout << rml.get_move_pv(j, k) << " ";
+
+ cout << endl;
+ }
+ alpha = rml.get_move_score(Min(i, MultiPV-1));
+ }
+ } // PV move or new best move
- assert(alpha >= oldAlpha);
+ assert(alpha >= oldAlpha);
+
+ AspirationFailLow = (alpha == oldAlpha);
+
+ if (AspirationFailLow && StopOnPonderhit)
+ StopOnPonderhit = false;
+ }
+
+ // Can we exit fail low loop ?
+ if (AbortSearch || alpha > oldAlpha)
+ break;
+
+ // Prepare for a research after a fail low, each time with a wider window
+ researchCount++;
+ alpha = Max(alpha - AspirationDelta * (1 << researchCount), -VALUE_INFINITE);
+ oldAlpha = alpha;
+
+ } // Fail low loop
- FailLow = (alpha == oldAlpha);
- }
return alpha;
}
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta > alpha && beta <= VALUE_INFINITE);
assert(ply >= 0 && ply < PLY_MAX);
- assert(threadID >= 0 && threadID < ActiveThreads);
+ assert(threadID >= 0 && threadID < TM.active_threads());
Move movesSearched[256];
StateInfo st;
Value oldAlpha, value;
bool isCheck, mateThreat, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
int moveCount = 0;
- Value bestValue = -VALUE_INFINITE;
+ Value bestValue = value = -VALUE_INFINITE;
if (depth < OnePly)
return qsearch(pos, ss, alpha, beta, Depth(0), ply, threadID);
init_node(ss, ply, threadID);
// After init_node() that calls poll()
- if (AbortSearch || thread_should_stop(threadID))
+ if (AbortSearch || TM.thread_should_stop(threadID))
return Value(0);
if (pos.is_draw() || ply >= PLY_MAX - 1)
tte = TT.retrieve(pos.get_key());
}
+ isCheck = pos.is_check();
+ if (!isCheck)
+ {
+ // Update gain statistics of the previous move that lead
+ // us in this position.
+ EvalInfo ei;
+ ss[ply].eval = evaluate(pos, ei, threadID);
+ update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
+ }
+
// Initialize a MovePicker object for the current position, and prepare
// to search all moves
- isCheck = pos.is_check();
mateThreat = pos.has_mate_threat(opposite_color(pos.side_to_move()));
CheckInfo ci(pos);
MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
// occurs.
while ( alpha < beta
&& (move = mp.get_next_move()) != MOVE_NONE
- && !thread_should_stop(threadID))
+ && !TM.thread_should_stop(threadID))
{
assert(move_is_ok(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.
+ bool doFullDepthSearch = true;
+
if ( depth >= 3*OnePly
&& !dangerous
&& !captureOrPromotion
&& !move_is_castle(move)
&& !move_is_killer(move, ss[ply]))
{
- double red = 0.5 + ln(moveCount) * ln(depth / 2) / 6.0;
- if (red >= 1.0)
- {
- ss[ply].reduction = Depth(int(floor(red * int(OnePly))));
- value = -search(pos, ss, -alpha, newDepth-ss[ply].reduction, ply+1, true, threadID);
- }
- else
- value = alpha + 1; // Just to trigger next condition
+ ss[ply].reduction = pv_reduction(depth, moveCount);
+ if (ss[ply].reduction)
+ {
+ value = -search(pos, ss, -alpha, newDepth-ss[ply].reduction, ply+1, true, threadID);
+ doFullDepthSearch = (value > alpha);
+ }
}
- else
- value = alpha + 1; // Just to trigger next condition
- if (value > alpha) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
ss[ply].reduction = Depth(0);
value = -search(pos, ss, -alpha, newDepth, ply+1, true, threadID);
if (value > alpha && value < beta)
- {
- // When the search fails high at ply 1 while searching the first
- // move at the root, set the flag failHighPly1. This is used for
- // time managment: We don't want to stop the search early in
- // such cases, because resolving the fail high at ply 1 could
- // result in a big drop in score at the root.
- if (ply == 1 && RootMoveNumber == 1)
- Threads[threadID].failHighPly1 = true;
-
- // A fail high occurred. Re-search at full window (pv search)
value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);
- Threads[threadID].failHighPly1 = false;
- }
}
}
pos.undo_move(move);
if (value == value_mate_in(ply + 1))
ss[ply].mateKiller = move;
}
- // If we are at ply 1, and we are searching the first root move at
- // ply 0, set the 'Problem' variable if the score has dropped a lot
- // (from the computer's point of view) since the previous iteration.
- if ( ply == 1
- && Iteration >= 2
- && -value <= IterationInfo[Iteration-1].value - ProblemMargin)
- Problem = true;
}
// Split?
- if ( ActiveThreads > 1
+ if ( TM.active_threads() > 1
&& bestValue < beta
&& depth >= MinimumSplitDepth
&& Iteration <= 99
- && idle_thread_exists(threadID)
+ && TM.available_thread_exists(threadID)
&& !AbortSearch
- && !thread_should_stop(threadID)
- && split(pos, ss, ply, &alpha, &beta, &bestValue, VALUE_NONE,
- depth, &moveCount, &mp, threadID, true))
+ && !TM.thread_should_stop(threadID)
+ && TM.split(pos, ss, ply, &alpha, &beta, &bestValue, VALUE_NONE,
+ depth, &moveCount, &mp, threadID, true))
break;
}
// If the search is not aborted, update the transposition table,
// history counters, and killer moves.
- if (AbortSearch || thread_should_stop(threadID))
+ if (AbortSearch || TM.thread_should_stop(threadID))
return bestValue;
if (bestValue <= oldAlpha)
else if (bestValue >= beta)
{
- BetaCounter.add(pos.side_to_move(), depth, threadID);
+ TM.incrementBetaCounter(pos.side_to_move(), depth, threadID);
move = ss[ply].pv[ply];
if (!pos.move_is_capture_or_promotion(move))
{
assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
assert(ply >= 0 && ply < PLY_MAX);
- assert(threadID >= 0 && threadID < ActiveThreads);
+ assert(threadID >= 0 && threadID < TM.active_threads());
Move movesSearched[256];
EvalInfo ei;
const TTEntry* tte;
Move ttMove, move;
Depth ext, newDepth;
- Value staticValue, nullValue, value, futilityValue, futilityValueScaled;
- bool isCheck, useFutilityPruning, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
+ Value bestValue, staticValue, nullValue, value, futilityValue, futilityValueScaled;
+ bool isCheck, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
int moveCount = 0;
- Value bestValue = -VALUE_INFINITE;
+ futilityValue = staticValue = bestValue = value = -VALUE_INFINITE;
if (depth < OnePly)
return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
init_node(ss, ply, threadID);
// After init_node() that calls poll()
- if (AbortSearch || thread_should_stop(threadID))
+ if (AbortSearch || TM.thread_should_stop(threadID))
return Value(0);
if (pos.is_draw() || ply >= PLY_MAX - 1)
}
isCheck = pos.is_check();
- ei.futilityMargin = Value(0); // Manually initialize futilityMargin
-
- // Calculate depth dependant futility pruning parameters
- const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8));
- const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2);
// Evaluate the position statically
- if (isCheck)
- ss[ply].eval = VALUE_NONE;
- else
+ if (!isCheck)
{
if (tte && (tte->type() & VALUE_TYPE_EVAL))
staticValue = value_from_tt(tte->value(), ply);
staticValue = evaluate(pos, ei, threadID);
ss[ply].eval = staticValue;
- futilityValue = staticValue + FutilityValueMargin;
+ futilityValue = staticValue + futility_margin(depth, 0); //FIXME: Remove me, only for split
staticValue = refine_eval(tte, staticValue, ply); // Enhance accuracy with TT value if possible
+ update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
}
+ // Static null move pruning. We're betting that the opponent doesn't have
+ // a move that will reduce the score by more than FutilityMargins[int(depth)]
+ // if we do a null move.
+ if ( !isCheck
+ && allowNullmove
+ && depth < RazorDepth
+ && staticValue - futility_margin(depth, 0) >= beta)
+ return staticValue - futility_margin(depth, 0);
+
// Null move search
if ( allowNullmove
&& depth > OnePly
&& !isCheck
&& !value_is_mate(beta)
&& ok_to_do_nullmove(pos)
- && staticValue >= beta - NullMoveMargin)
+ && staticValue >= beta - (depth >= 4 * OnePly ? NullMoveMargin : 0))
{
ss[ply].currentMove = MOVE_NULL;
// Go with internal iterative deepening if we don't have a TT move
if (UseIIDAtNonPVNodes && ttMove == MOVE_NONE && depth >= 8*OnePly &&
- !isCheck && evaluate(pos, ei, threadID) >= beta - IIDMargin)
+ !isCheck && ss[ply].eval >= beta - IIDMargin)
{
search(pos, ss, beta, Min(depth/2, depth-2*OnePly), ply, false, threadID);
ttMove = ss[ply].pv[ply];
- tte = TT.retrieve(pos.get_key());
+ tte = TT.retrieve(posKey);
}
// Initialize a MovePicker object for the current position, and prepare
// to search all moves.
MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
CheckInfo ci(pos);
- useFutilityPruning = depth < SelectiveDepth && !isCheck;
// Loop through all legal moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
&& (move = mp.get_next_move()) != MOVE_NONE
- && !thread_should_stop(threadID))
+ && !TM.thread_should_stop(threadID))
{
assert(move_is_ok(move));
movesSearched[moveCount++] = ss[ply].currentMove = move;
// Futility pruning
- if ( useFutilityPruning
+ if ( !isCheck
&& !dangerous
&& !captureOrPromotion
+ && !move_is_castle(move)
&& move != ttMove)
{
// Move count based pruning
- if ( moveCount >= FutilityMoveCountMargin
+ if ( moveCount >= futility_move_count(depth)
&& ok_to_prune(pos, move, ss[ply].threatMove)
&& bestValue > value_mated_in(PLY_MAX))
continue;
// Value based pruning
- futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin;
+ Depth predictedDepth = newDepth - nonpv_reduction(depth, moveCount); //FIXME: We are ignoring condition: depth >= 3*OnePly, BUG??
+ futilityValueScaled = ss[ply].eval + futility_margin(predictedDepth, moveCount)
+ + H.gain(pos.piece_on(move_from(move)), move_to(move)) + 45;
if (futilityValueScaled < beta)
{
// 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.
+ bool doFullDepthSearch = true;
+
if ( depth >= 3*OnePly
&& !dangerous
&& !captureOrPromotion
&& !move_is_castle(move)
- && !move_is_killer(move, ss[ply])
- /* && move != ttMove*/)
+ && !move_is_killer(move, ss[ply]))
{
- double red = 0.5 + ln(moveCount) * ln(depth / 2) / 3.0;
- if (red >= 1.0)
+ ss[ply].reduction = nonpv_reduction(depth, moveCount);
+ if (ss[ply].reduction)
{
- ss[ply].reduction = Depth(int(floor(red * int(OnePly))));
value = -search(pos, ss, -(beta-1), newDepth-ss[ply].reduction, ply+1, true, threadID);
+ doFullDepthSearch = (value >= beta);
}
- else
- value = beta; // Just to trigger next condition
}
- else
- value = beta; // Just to trigger next condition
- if (value >= beta) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
ss[ply].reduction = Depth(0);
value = -search(pos, ss, -(beta-1), newDepth, ply+1, true, threadID);
}
// Split?
- if ( ActiveThreads > 1
+ if ( TM.active_threads() > 1
&& bestValue < beta
&& depth >= MinimumSplitDepth
&& Iteration <= 99
- && idle_thread_exists(threadID)
+ && TM.available_thread_exists(threadID)
&& !AbortSearch
- && !thread_should_stop(threadID)
- && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue,
- depth, &moveCount, &mp, threadID, false))
+ && !TM.thread_should_stop(threadID)
+ && TM.split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, //FIXME: SMP & futilityValue
+ depth, &moveCount, &mp, threadID, false))
break;
}
// If the search is not aborted, update the transposition table,
// history counters, and killer moves.
- if (AbortSearch || thread_should_stop(threadID))
+ if (AbortSearch || TM.thread_should_stop(threadID))
return bestValue;
if (bestValue < beta)
TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, depth, MOVE_NONE);
else
{
- BetaCounter.add(pos.side_to_move(), depth, threadID);
+ TM.incrementBetaCounter(pos.side_to_move(), depth, threadID);
move = ss[ply].pv[ply];
TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, move);
if (!pos.move_is_capture_or_promotion(move))
assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
assert(depth <= 0);
assert(ply >= 0 && ply < PLY_MAX);
- assert(threadID >= 0 && threadID < ActiveThreads);
+ assert(threadID >= 0 && threadID < TM.active_threads());
EvalInfo ei;
StateInfo st;
Move ttMove, move;
Value staticValue, bestValue, value, futilityBase, futilityValue;
- bool isCheck, enoughMaterial, moveIsCheck;
+ bool isCheck, enoughMaterial, moveIsCheck, evasionPrunable;
const TTEntry* tte = NULL;
int moveCount = 0;
bool pvNode = (beta - alpha != 1);
+ Value oldAlpha = alpha;
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
init_node(ss, ply, threadID);
// After init_node() that calls poll()
- if (AbortSearch || thread_should_stop(threadID))
+ if (AbortSearch || TM.thread_should_stop(threadID))
return Value(0);
if (pos.is_draw() || ply >= PLY_MAX - 1)
}
isCheck = pos.is_check();
- ei.futilityMargin = Value(0); // Manually initialize futilityMargin
// Evaluate the position statically
if (isCheck)
else
staticValue = evaluate(pos, ei, threadID);
+ if (!isCheck)
+ {
+ ss[ply].eval = staticValue;
+ update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
+ }
+
// Initialize "stand pat score", and return it immediately if it is
// at least beta.
bestValue = staticValue;
if (bestValue >= beta)
{
// Store the score to avoid a future costly evaluation() call
- if (!isCheck && !tte && ei.futilityMargin == 0)
+ if (!isCheck && !tte && ei.futilityMargin[pos.side_to_move()] == 0)
TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EV_LO, Depth(-127*OnePly), MOVE_NONE);
return bestValue;
if (bestValue > alpha)
alpha = bestValue;
+ // If we are near beta then try to get a cutoff pushing checks a bit further
+ bool deepChecks = depth == -OnePly && staticValue >= beta - PawnValueMidgame / 8;
+
// 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, H);
+ // to search the moves. Because the depth is <= 0 here, only captures,
+ // queen promotions and checks (only if depth == 0 or depth == -OnePly
+ // and we are near beta) will be generated.
+ MovePicker mp = MovePicker(pos, ttMove, deepChecks ? Depth(0) : depth, H);
CheckInfo ci(pos);
enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame;
- futilityBase = staticValue + FutilityMarginQS + ei.futilityMargin;
+ futilityBase = staticValue + FutilityMarginQS + ei.futilityMargin[pos.side_to_move()];
// Loop through the moves until no moves remain or a beta cutoff
// occurs.
}
}
- // Don't search captures and checks with negative SEE values
- if ( !isCheck
+ // Detect blocking evasions that are candidate to be pruned
+ evasionPrunable = isCheck
+ && bestValue != -VALUE_INFINITE
+ && !pos.move_is_capture(move)
+ && pos.type_of_piece_on(move_from(move)) != KING
+ && !pos.can_castle(pos.side_to_move());
+
+ // Don't search moves with negative SEE values
+ if ( (!isCheck || evasionPrunable)
+ && !pvNode
&& move != ttMove
&& !move_is_promotion(move)
&& pos.see_sign(move) < 0)
// Update transposition table
Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
- if (bestValue < beta)
+ if (bestValue <= oldAlpha)
{
// If bestValue isn't changed it means it is still the static evaluation
// of the node, so keep this info to avoid a future evaluation() call.
- ValueType type = (bestValue == staticValue && !ei.futilityMargin ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER);
+ ValueType type = (bestValue == staticValue && !ei.futilityMargin[pos.side_to_move()] ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER);
TT.store(pos.get_key(), value_to_tt(bestValue, ply), type, d, MOVE_NONE);
}
- else
+ else if (bestValue >= beta)
{
move = ss[ply].pv[ply];
TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, move);
if (!pos.move_is_capture_or_promotion(move))
update_killers(move, ss[ply]);
}
+ else
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, d, ss[ply].pv[ply]);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
void sp_search(SplitPoint* sp, int threadID) {
- assert(threadID >= 0 && threadID < ActiveThreads);
- assert(ActiveThreads > 1);
+ assert(threadID >= 0 && threadID < TM.active_threads());
+ assert(TM.active_threads() > 1);
- Position pos = Position(sp->pos);
+ Position pos(*sp->pos);
CheckInfo ci(pos);
SearchStack* ss = sp->sstack[threadID];
- Value value;
+ Value value = -VALUE_INFINITE;
Move move;
+ int moveCount;
bool isCheck = pos.is_check();
- bool useFutilityPruning = sp->depth < SelectiveDepth
+ bool useFutilityPruning = sp->depth < 7 * OnePly //FIXME: sync with search
&& !isCheck;
- const int FutilityMoveCountMargin = 3 + (1 << (3 * int(sp->depth) / 8));
- const int FutilityValueMargin = 112 * bitScanReverse32(int(sp->depth) * int(sp->depth) / 2);
-
- while ( sp->bestValue < sp->beta
- && !thread_should_stop(threadID)
- && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE)
+ while ( lock_grab_bool(&(sp->lock))
+ && sp->bestValue < sp->beta
+ && !TM.thread_should_stop(threadID)
+ && (move = sp->mp->get_next_move()) != MOVE_NONE)
{
+ moveCount = ++sp->moves;
+ lock_release(&(sp->lock));
+
assert(move_is_ok(move));
bool moveIsCheck = pos.move_is_check(move, ci);
bool captureOrPromotion = pos.move_is_capture_or_promotion(move);
- lock_grab(&(sp->lock));
- int moveCount = ++sp->moves;
- lock_release(&(sp->lock));
-
ss[sp->ply].currentMove = move;
- // Decide the new search depth.
+ // Decide the new search depth
bool dangerous;
Depth ext = extension(pos, move, false, captureOrPromotion, moveIsCheck, false, false, &dangerous);
Depth newDepth = sp->depth - OnePly + ext;
&& !captureOrPromotion)
{
// Move count based pruning
- if ( moveCount >= FutilityMoveCountMargin
+ if ( moveCount >= futility_move_count(sp->depth)
&& ok_to_prune(pos, move, ss[sp->ply].threatMove)
&& sp->bestValue > value_mated_in(PLY_MAX))
continue;
// Value based pruning
- if (sp->futilityValue == VALUE_NONE)
- {
- EvalInfo ei;
- sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
- }
-
- Value futilityValueScaled = sp->futilityValue - moveCount * IncrementalFutilityMargin;
+ Value futilityValueScaled = sp->futilityValue - moveCount * 8; //FIXME: sync with search
if (futilityValueScaled < sp->beta)
{
// 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.
+ bool doFullDepthSearch = true;
+
if ( !dangerous
&& !captureOrPromotion
&& !move_is_castle(move)
&& !move_is_killer(move, ss[sp->ply]))
{
- double red = 0.5 + ln(moveCount) * ln(sp->depth / 2) / 3.0;
- if (red >= 1.0)
+ ss[sp->ply].reduction = nonpv_reduction(sp->depth, moveCount);
+ if (ss[sp->ply].reduction)
{
- ss[sp->ply].reduction = Depth(int(floor(red * int(OnePly))));
value = -search(pos, ss, -(sp->beta-1), newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
+ doFullDepthSearch = (value >= sp->beta);
}
- else
- value = sp->beta; // Just to trigger next condition
}
- else
- value = sp->beta; // Just to trigger next condition
- if (value >= sp->beta) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
ss[sp->ply].reduction = Depth(0);
value = -search(pos, ss, -(sp->beta - 1), newDepth, sp->ply+1, true, threadID);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
- if (thread_should_stop(threadID))
- break;
-
// New best move?
if (value > sp->bestValue) // Less then 2% of cases
{
lock_grab(&(sp->lock));
- if (value > sp->bestValue && !thread_should_stop(threadID))
+ if (value > sp->bestValue && !TM.thread_should_stop(threadID))
{
sp->bestValue = value;
if (sp->bestValue >= sp->beta)
{
+ sp->stopRequest = true;
sp_update_pv(sp->parentSstack, ss, sp->ply);
- for (int i = 0; i < ActiveThreads; i++)
- if (i != threadID && (i == sp->master || sp->slaves[i]))
- Threads[i].stop = true;
-
- sp->finished = true;
}
}
lock_release(&(sp->lock));
}
}
- lock_grab(&(sp->lock));
-
- // If this is the master thread and we have been asked to stop because of
- // a beta cutoff higher up in the tree, stop all slave threads.
- if (sp->master == threadID && thread_should_stop(threadID))
- for (int i = 0; i < ActiveThreads; i++)
- if (sp->slaves[i])
- Threads[i].stop = true;
+ /* Here we have the lock still grabbed */
sp->cpus--;
sp->slaves[threadID] = 0;
void sp_search_pv(SplitPoint* sp, int threadID) {
- assert(threadID >= 0 && threadID < ActiveThreads);
- assert(ActiveThreads > 1);
+ assert(threadID >= 0 && threadID < TM.active_threads());
+ assert(TM.active_threads() > 1);
- Position pos = Position(sp->pos);
+ Position pos(*sp->pos);
CheckInfo ci(pos);
SearchStack* ss = sp->sstack[threadID];
- Value value;
+ Value value = -VALUE_INFINITE;
+ int moveCount;
Move move;
- while ( sp->alpha < sp->beta
- && !thread_should_stop(threadID)
- && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE)
+ while ( lock_grab_bool(&(sp->lock))
+ && sp->alpha < sp->beta
+ && !TM.thread_should_stop(threadID)
+ && (move = sp->mp->get_next_move()) != MOVE_NONE)
{
- bool moveIsCheck = pos.move_is_check(move, ci);
- bool captureOrPromotion = pos.move_is_capture_or_promotion(move);
+ moveCount = ++sp->moves;
+ lock_release(&(sp->lock));
assert(move_is_ok(move));
- lock_grab(&(sp->lock));
- int moveCount = ++sp->moves;
- lock_release(&(sp->lock));
+ bool moveIsCheck = pos.move_is_check(move, ci);
+ bool captureOrPromotion = pos.move_is_capture_or_promotion(move);
ss[sp->ply].currentMove = move;
- // Decide the new search depth.
+ // Decide the new search depth
bool dangerous;
Depth ext = extension(pos, move, true, captureOrPromotion, moveIsCheck, false, false, &dangerous);
Depth newDepth = sp->depth - OnePly + ext;
// 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.
+ bool doFullDepthSearch = true;
+
if ( !dangerous
&& !captureOrPromotion
&& !move_is_castle(move)
&& !move_is_killer(move, ss[sp->ply]))
{
- double red = 0.5 + ln(moveCount) * ln(sp->depth / 2) / 6.0;
- if (red >= 1.0)
+ ss[sp->ply].reduction = pv_reduction(sp->depth, moveCount);
+ if (ss[sp->ply].reduction)
{
- ss[sp->ply].reduction = Depth(int(floor(red * int(OnePly))));
- value = -search(pos, ss, -sp->alpha, newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
+ Value localAlpha = sp->alpha;
+ value = -search(pos, ss, -localAlpha, newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
+ doFullDepthSearch = (value > localAlpha);
}
- else
- value = sp->alpha + 1; // Just to trigger next condition
}
- else
- value = sp->alpha + 1; // Just to trigger next condition
- if (value > sp->alpha) // Go with full depth non-pv search
+ if (doFullDepthSearch) // Go with full depth non-pv search
{
+ Value localAlpha = sp->alpha;
ss[sp->ply].reduction = Depth(0);
- value = -search(pos, ss, -sp->alpha, newDepth, sp->ply+1, true, threadID);
+ value = -search(pos, ss, -localAlpha, newDepth, sp->ply+1, true, threadID);
- if (value > sp->alpha && value < sp->beta)
+ if (value > localAlpha && value < sp->beta)
{
- // When the search fails high at ply 1 while searching the first
- // move at the root, set the flag failHighPly1. This is used for
- // time managment: We don't want to stop the search early in
- // such cases, because resolving the fail high at ply 1 could
- // result in a big drop in score at the root.
- if (sp->ply == 1 && RootMoveNumber == 1)
- Threads[threadID].failHighPly1 = true;
-
- value = -search_pv(pos, ss, -sp->beta, -sp->alpha, newDepth, sp->ply+1, threadID);
- Threads[threadID].failHighPly1 = false;
+ // If another thread has failed high then sp->alpha has been increased
+ // to be higher or equal then beta, if so, avoid to start a PV search.
+ localAlpha = sp->alpha;
+ if (localAlpha < sp->beta)
+ value = -search_pv(pos, ss, -sp->beta, -localAlpha, newDepth, sp->ply+1, threadID);
+ else
+ assert(TM.thread_should_stop(threadID));
}
}
pos.undo_move(move);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
- if (thread_should_stop(threadID))
- break;
-
// New best move?
- lock_grab(&(sp->lock));
- if (value > sp->bestValue && !thread_should_stop(threadID))
+ if (value > sp->bestValue) // Less then 2% of cases
{
- sp->bestValue = value;
- if (value > sp->alpha)
+ lock_grab(&(sp->lock));
+ if (value > sp->bestValue && !TM.thread_should_stop(threadID))
{
- sp->alpha = value;
- sp_update_pv(sp->parentSstack, ss, sp->ply);
- if (value == value_mate_in(sp->ply + 1))
- ss[sp->ply].mateKiller = move;
-
- if (value >= sp->beta)
+ sp->bestValue = value;
+ if (value > sp->alpha)
{
- for (int i = 0; i < ActiveThreads; i++)
- if (i != threadID && (i == sp->master || sp->slaves[i]))
- Threads[i].stop = true;
+ // Ask threads to stop before to modify sp->alpha
+ if (value >= sp->beta)
+ sp->stopRequest = true;
- sp->finished = true;
+ sp->alpha = value;
+
+ sp_update_pv(sp->parentSstack, ss, sp->ply);
+ if (value == value_mate_in(sp->ply + 1))
+ ss[sp->ply].mateKiller = move;
}
- }
- // If we are at ply 1, and we are searching the first root move at
- // ply 0, set the 'Problem' variable if the score has dropped a lot
- // (from the computer's point of view) since the previous iteration.
- if ( sp->ply == 1
- && Iteration >= 2
- && -value <= IterationInfo[Iteration-1].value - ProblemMargin)
- Problem = true;
+ }
+ lock_release(&(sp->lock));
}
- lock_release(&(sp->lock));
}
- lock_grab(&(sp->lock));
-
- // If this is the master thread and we have been asked to stop because of
- // a beta cutoff higher up in the tree, stop all slave threads.
- if (sp->master == threadID && thread_should_stop(threadID))
- for (int i = 0; i < ActiveThreads; i++)
- if (sp->slaves[i])
- Threads[i].stop = true;
+ /* Here we have the lock still grabbed */
sp->cpus--;
sp->slaves[threadID] = 0;
lock_release(&(sp->lock));
}
- /// The BetaCounterType class
-
- BetaCounterType::BetaCounterType() { clear(); }
- void BetaCounterType::clear() {
-
- for (int i = 0; i < THREAD_MAX; i++)
- Threads[i].betaCutOffs[WHITE] = Threads[i].betaCutOffs[BLACK] = 0ULL;
- }
+ // init_node() is called at the beginning of all the search functions
+ // (search(), search_pv(), qsearch(), and so on) and initializes the
+ // search stack object corresponding to the current node. Once every
+ // NodesBetweenPolls nodes, init_node() also calls poll(), which polls
+ // for user input and checks whether it is time to stop the search.
- void BetaCounterType::add(Color us, Depth d, int threadID) {
+ void init_node(SearchStack ss[], int ply, int threadID) {
- // Weighted count based on depth
- Threads[threadID].betaCutOffs[us] += unsigned(d);
- }
+ assert(ply >= 0 && ply < PLY_MAX);
+ assert(threadID >= 0 && threadID < TM.active_threads());
- void BetaCounterType::read(Color us, int64_t& our, int64_t& their) {
+ TM.incrementNodeCounter(threadID);
- our = their = 0UL;
- for (int i = 0; i < THREAD_MAX; i++)
+ if (threadID == 0)
{
- our += Threads[i].betaCutOffs[us];
- their += Threads[i].betaCutOffs[opposite_color(us)];
+ NodesSincePoll++;
+ if (NodesSincePoll >= NodesBetweenPolls)
+ {
+ poll();
+ NodesSincePoll = 0;
+ }
}
+ ss[ply].init(ply);
+ ss[ply + 2].initKillers();
+ TM.print_current_line(ss, ply, threadID);
}
- /// The RootMoveList class
+ // update_pv() is called whenever a search returns a value > alpha.
+ // It updates the PV in the SearchStack object corresponding to the
+ // current node.
- // RootMoveList c'tor
+ void update_pv(SearchStack ss[], int ply) {
- RootMoveList::RootMoveList(Position& pos, Move searchMoves[]) : count(0) {
-
- MoveStack mlist[MaxRootMoves];
- bool includeAllMoves = (searchMoves[0] == MOVE_NONE);
-
- // Generate all legal moves
- MoveStack* last = generate_moves(pos, mlist);
-
- // Add each move to the moves[] array
- for (MoveStack* cur = mlist; cur != last; cur++)
- {
- bool includeMove = includeAllMoves;
-
- for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++)
- 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 = 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);
- moves[count].pv[0] = moves[count].move;
- moves[count].pv[1] = MOVE_NONE;
- count++;
- }
- sort();
- }
-
-
- // RootMoveList simple methods definitions
-
- void RootMoveList::set_move_nodes(int moveNum, int64_t nodes) {
-
- moves[moveNum].nodes = nodes;
- moves[moveNum].cumulativeNodes += nodes;
- }
-
- void RootMoveList::set_beta_counters(int moveNum, int64_t our, int64_t their) {
-
- moves[moveNum].ourBeta = our;
- moves[moveNum].theirBeta = their;
- }
-
- void RootMoveList::set_move_pv(int moveNum, const Move pv[]) {
-
- int j;
-
- for (j = 0; pv[j] != MOVE_NONE; j++)
- moves[moveNum].pv[j] = pv[j];
-
- moves[moveNum].pv[j] = MOVE_NONE;
- }
-
-
- // RootMoveList::sort() sorts the root move list at the beginning of a new
- // iteration.
-
- void RootMoveList::sort() {
-
- sort_multipv(count - 1); // Sort all items
- }
-
-
- // RootMoveList::sort_multipv() sorts the first few moves in the root move
- // list by their scores and depths. It is used to order the different PVs
- // correctly in MultiPV mode.
-
- void RootMoveList::sort_multipv(int n) {
-
- int i,j;
-
- for (i = 1; i <= n; i++)
- {
- RootMove rm = moves[i];
- for (j = i; j > 0 && moves[j - 1] < rm; j--)
- moves[j] = moves[j - 1];
-
- moves[j] = rm;
- }
- }
-
-
- // init_node() is called at the beginning of all the search functions
- // (search(), search_pv(), qsearch(), and so on) and initializes the
- // search stack object corresponding to the current node. Once every
- // NodesBetweenPolls nodes, init_node() also calls poll(), which polls
- // for user input and checks whether it is time to stop the search.
-
- void init_node(SearchStack ss[], int ply, int threadID) {
-
- assert(ply >= 0 && ply < PLY_MAX);
- assert(threadID >= 0 && threadID < ActiveThreads);
-
- Threads[threadID].nodes++;
-
- if (threadID == 0)
- {
- NodesSincePoll++;
- if (NodesSincePoll >= NodesBetweenPolls)
- {
- poll();
- NodesSincePoll = 0;
- }
- }
- ss[ply].init(ply);
- ss[ply + 2].initKillers();
-
- if (Threads[threadID].printCurrentLine)
- print_current_line(ss, ply, threadID);
- }
-
-
- // update_pv() is called whenever a search returns a value > alpha.
- // It updates the PV in the SearchStack object corresponding to the
- // current node.
-
- void update_pv(SearchStack ss[], int ply) {
-
- assert(ply >= 0 && ply < PLY_MAX);
+ assert(ply >= 0 && ply < PLY_MAX);
int p;
Square mfrom, mto, tfrom, tto;
- // Prune if there isn't any threat move and
- // is not a castling move (common case).
- if (threat == MOVE_NONE && !move_is_castle(m))
+ // Prune if there isn't any threat move
+ if (threat == MOVE_NONE)
return true;
mfrom = move_from(m);
tfrom = move_from(threat);
tto = move_to(threat);
- // Case 1: Castling moves are never pruned
- if (move_is_castle(m))
- return false;
-
- // Case 2: Don't prune moves which move the threatened piece
+ // Case 1: Don't prune moves which move the threatened piece
if (mfrom == tto)
return false;
- // Case 3: If the threatened piece has value less than or equal to the
+ // Case 2: If the threatened piece has value less than or equal to the
// value of the threatening piece, don't prune move which defend it.
if ( pos.move_is_capture(threat)
&& ( pos.midgame_value_of_piece_on(tfrom) >= pos.midgame_value_of_piece_on(tto)
&& pos.move_attacks_square(m, tto))
return false;
- // Case 4: If the moving piece in the threatened move is a slider, don't
+ // 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))
&& bit_is_set(squares_between(tfrom, tto), mto)
return defaultEval;
}
+
// update_history() registers a good move that produced a beta-cutoff
// in history and marks as failures all the other moves of that ply.
}
- // 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 management.
-
- bool fail_high_ply_1() {
+ // update_gains() updates the gains table of a non-capture move given
+ // the static position evaluation before and after the move.
- for (int i = 0; i < ActiveThreads; i++)
- if (Threads[i].failHighPly1)
- return true;
+ void update_gains(const Position& pos, Move m, Value before, Value after) {
- return false;
+ if ( m != MOVE_NULL
+ && before != VALUE_NONE
+ && after != VALUE_NONE
+ && pos.captured_piece() == NO_PIECE_TYPE
+ && !move_is_castle(m)
+ && !move_is_promotion(m))
+ H.set_gain(pos.piece_on(move_to(m)), move_to(m), -(before + after));
}
int nps() {
int t = current_search_time();
- return (t > 0 ? int((nodes_searched() * 1000) / t) : 0);
+ return (t > 0 ? int((TM.nodes_searched() * 1000) / t) : 0);
}
else if (t - lastInfoTime >= 1000)
{
lastInfoTime = t;
- lock_grab(&IOLock);
+ lock_grab(&TM.IOLock);
if (dbg_show_mean)
dbg_print_mean();
if (dbg_show_hit_rate)
dbg_print_hit_rate();
- cout << "info nodes " << nodes_searched() << " nps " << nps()
+ cout << "info nodes " << TM.nodes_searched() << " nps " << nps()
<< " time " << t << " hashfull " << TT.full() << endl;
- lock_release(&IOLock);
+ lock_release(&TM.IOLock);
if (ShowCurrentLine)
- Threads[0].printCurrentLine = true;
+ TM.threads[0].printCurrentLineRequest = true;
}
// Should we stop the search?
return;
bool stillAtFirstMove = RootMoveNumber == 1
- && !FailLow
+ && !AspirationFailLow
&& t > MaxSearchTime + ExtraSearchTime;
- bool noProblemFound = !FailHigh
- && !FailLow
- && !fail_high_ply_1()
- && !Problem
- && t > 6 * (MaxSearchTime + ExtraSearchTime);
-
bool noMoreTime = t > AbsoluteMaxSearchTime
- || stillAtFirstMove //FIXME: We are not checking any problem flags, BUG?
- || noProblemFound;
+ || stillAtFirstMove;
if ( (Iteration >= 3 && UseTimeManagement && noMoreTime)
|| (ExactMaxTime && t >= ExactMaxTime)
- || (Iteration >= 3 && MaxNodes && nodes_searched() >= MaxNodes))
+ || (Iteration >= 3 && MaxNodes && TM.nodes_searched() >= MaxNodes))
AbortSearch = true;
}
PonderSearch = false;
bool stillAtFirstMove = RootMoveNumber == 1
- && !FailLow
+ && !AspirationFailLow
&& t > MaxSearchTime + ExtraSearchTime;
- bool noProblemFound = !FailHigh
- && !FailLow
- && !fail_high_ply_1()
- && !Problem
- && t > 6 * (MaxSearchTime + ExtraSearchTime);
-
bool noMoreTime = t > AbsoluteMaxSearchTime
- || stillAtFirstMove
- || noProblemFound;
+ || stillAtFirstMove;
if (Iteration >= 3 && UseTimeManagement && (noMoreTime || StopOnPonderhit))
AbortSearch = true;
}
- // print_current_line() prints the current line of search for a given
- // thread. Called when the UCI option UCI_ShowCurrLine is 'true'.
-
- void print_current_line(SearchStack ss[], int ply, int threadID) {
-
- assert(ply >= 0 && ply < PLY_MAX);
- assert(threadID >= 0 && threadID < ActiveThreads);
-
- if (!Threads[threadID].idle)
- {
- lock_grab(&IOLock);
- cout << "info currline " << (threadID + 1);
- for (int p = 0; p < ply; p++)
- cout << " " << ss[p].currentMove;
-
- cout << endl;
- lock_release(&IOLock);
- }
- Threads[threadID].printCurrentLine = false;
- if (threadID + 1 < ActiveThreads)
- Threads[threadID + 1].printCurrentLine = true;
- }
-
-
// init_ss_array() does a fast reset of the first entries of a SearchStack array
void init_ss_array(SearchStack ss[]) {
}
+ // init_thread() is the function which is called when a new thread is
+ // launched. It simply calls the idle_loop() function with the supplied
+ // threadID. There are two versions of this function; one for POSIX
+ // threads and one for Windows threads.
+
+#if !defined(_MSC_VER)
+
+ void* init_thread(void *threadID) {
+
+ TM.idle_loop(*(int*)threadID, NULL);
+ return NULL;
+ }
+
+#else
+
+ DWORD WINAPI init_thread(LPVOID threadID) {
+
+ TM.idle_loop(*(int*)threadID, NULL);
+ return NULL;
+ }
+
+#endif
+
+
+ /// The ThreadsManager class
+
+ // resetNodeCounters(), resetBetaCounters(), searched_nodes() and
+ // get_beta_counters() are getters/setters for the per thread
+ // counters used to sort the moves at root.
+
+ void ThreadsManager::resetNodeCounters() {
+
+ for (int i = 0; i < MAX_THREADS; i++)
+ threads[i].nodes = 0ULL;
+ }
+
+ void ThreadsManager::resetBetaCounters() {
+
+ for (int i = 0; i < MAX_THREADS; i++)
+ threads[i].betaCutOffs[WHITE] = threads[i].betaCutOffs[BLACK] = 0ULL;
+ }
+
+ int64_t ThreadsManager::nodes_searched() const {
+
+ int64_t result = 0ULL;
+ for (int i = 0; i < ActiveThreads; i++)
+ result += threads[i].nodes;
+
+ return result;
+ }
+
+ void ThreadsManager::get_beta_counters(Color us, int64_t& our, int64_t& their) const {
+
+ our = their = 0UL;
+ for (int i = 0; i < MAX_THREADS; i++)
+ {
+ our += threads[i].betaCutOffs[us];
+ their += threads[i].betaCutOffs[opposite_color(us)];
+ }
+ }
+
+
// idle_loop() is where the threads are parked when they have no work to do.
// The parameter "waitSp", if non-NULL, is a pointer to an active SplitPoint
// object for which the current thread is the master.
- void idle_loop(int threadID, SplitPoint* waitSp) {
-
- assert(threadID >= 0 && threadID < THREAD_MAX);
+ void ThreadsManager::idle_loop(int threadID, SplitPoint* waitSp) {
- Threads[threadID].running = true;
+ assert(threadID >= 0 && threadID < MAX_THREADS);
while (true)
{
- if (AllThreadsShouldExit && threadID != 0)
- break;
+ // Slave threads can exit as soon as AllThreadsShouldExit raises,
+ // master should exit as last one.
+ if (AllThreadsShouldExit && !waitSp)
+ {
+ threads[threadID].state = THREAD_TERMINATED;
+ return;
+ }
// If we are not thinking, wait for a condition to be signaled
// instead of wasting CPU time polling for work.
- while (threadID != 0 && (Idle || threadID >= ActiveThreads))
+ while ( threadID != 0
+ && !AllThreadsShouldExit
+ && (AllThreadsShouldSleep || threadID >= ActiveThreads))
{
+ threads[threadID].state = THREAD_SLEEPING;
#if !defined(_MSC_VER)
pthread_mutex_lock(&WaitLock);
- if (Idle || threadID >= ActiveThreads)
- pthread_cond_wait(&WaitCond, &WaitLock);
-
+ pthread_cond_wait(&WaitCond, &WaitLock);
pthread_mutex_unlock(&WaitLock);
#else
WaitForSingleObject(SitIdleEvent[threadID], INFINITE);
#endif
+ // State is already changed by wake_sleeping_threads()
+ assert(threads[threadID].state == THREAD_AVAILABLE || threadID >= ActiveThreads);
}
- // If this thread has been assigned work, launch a search
- if (Threads[threadID].workIsWaiting)
- {
- Threads[threadID].workIsWaiting = false;
- if (Threads[threadID].splitPoint->pvNode)
- sp_search_pv(Threads[threadID].splitPoint, threadID);
- else
- sp_search(Threads[threadID].splitPoint, threadID);
+ // If this thread has been assigned work, launch a search
+ if (threads[threadID].state == THREAD_WORKISWAITING)
+ {
+ assert(!AllThreadsShouldExit);
- Threads[threadID].idle = true;
- }
+ threads[threadID].state = THREAD_SEARCHING;
- // If this thread is the master of a split point and all threads have
- // finished their work at this split point, return from the idle loop.
- if (waitSp != NULL && waitSp->cpus == 0)
- return;
- }
+ if (threads[threadID].splitPoint->pvNode)
+ sp_search_pv(threads[threadID].splitPoint, threadID);
+ else
+ sp_search(threads[threadID].splitPoint, threadID);
+
+ assert(threads[threadID].state == THREAD_SEARCHING);
+
+ threads[threadID].state = THREAD_AVAILABLE;
+ }
+
+ // If this thread is the master of a split point and all threads have
+ // finished their work at this split point, return from the idle loop.
+ if (waitSp != NULL && waitSp->cpus == 0)
+ {
+ assert( threads[threadID].state == THREAD_AVAILABLE
+ || threads[threadID].state == THREAD_SEARCHING);
- Threads[threadID].running = false;
+ threads[threadID].state = THREAD_SEARCHING;
+ return;
+ }
+ }
}
- // init_split_point_stack() is called during program initialization, and
- // initializes all split point objects.
+ // init_threads() is called during startup. It launches all helper threads,
+ // and initializes the split point stack and the global locks and condition
+ // objects.
- void init_split_point_stack() {
+ void ThreadsManager::init_threads() {
- for (int i = 0; i < THREAD_MAX; i++)
+ volatile int i;
+ bool ok;
+
+#if !defined(_MSC_VER)
+ pthread_t pthread[1];
+#endif
+
+ // Initialize global locks
+ lock_init(&MPLock, NULL);
+ lock_init(&IOLock, NULL);
+
+ // Initialize SplitPointStack locks
+ for (i = 0; i < MAX_THREADS; i++)
for (int j = 0; j < ACTIVE_SPLIT_POINTS_MAX; j++)
{
SplitPointStack[i][j].parent = NULL;
lock_init(&(SplitPointStack[i][j].lock), NULL);
}
+
+#if !defined(_MSC_VER)
+ pthread_mutex_init(&WaitLock, NULL);
+ pthread_cond_init(&WaitCond, NULL);
+#else
+ for (i = 0; i < MAX_THREADS; i++)
+ SitIdleEvent[i] = CreateEvent(0, FALSE, FALSE, 0);
+#endif
+
+ // Will be set just before program exits to properly end the threads
+ AllThreadsShouldExit = false;
+
+ // Threads will be put to sleep as soon as created
+ AllThreadsShouldSleep = true;
+
+ // All threads except the main thread should be initialized to THREAD_AVAILABLE
+ ActiveThreads = 1;
+ threads[0].state = THREAD_SEARCHING;
+ for (i = 1; i < MAX_THREADS; i++)
+ threads[i].state = THREAD_AVAILABLE;
+
+ // Launch the helper threads
+ for (i = 1; i < MAX_THREADS; i++)
+ {
+
+#if !defined(_MSC_VER)
+ ok = (pthread_create(pthread, NULL, init_thread, (void*)(&i)) == 0);
+#else
+ DWORD iID[1];
+ ok = (CreateThread(NULL, 0, init_thread, (LPVOID)(&i), 0, iID) != NULL);
+#endif
+
+ if (!ok)
+ {
+ cout << "Failed to create thread number " << i << endl;
+ Application::exit_with_failure();
+ }
+
+ // Wait until the thread has finished launching and is gone to sleep
+ while (threads[i].state != THREAD_SLEEPING);
+ }
}
- // destroy_split_point_stack() is called when the program exits, and
- // destroys all locks in the precomputed split point objects.
+ // exit_threads() is called when the program exits. It makes all the
+ // helper threads exit cleanly.
+
+ void ThreadsManager::exit_threads() {
- void destroy_split_point_stack() {
+ ActiveThreads = MAX_THREADS; // HACK
+ AllThreadsShouldSleep = true; // HACK
+ wake_sleeping_threads();
- for (int i = 0; i < THREAD_MAX; i++)
+ // This makes the threads to exit idle_loop()
+ AllThreadsShouldExit = true;
+
+ // Wait for thread termination
+ for (int i = 1; i < MAX_THREADS; i++)
+ while (threads[i].state != THREAD_TERMINATED);
+
+ // Now we can safely destroy the locks
+ for (int i = 0; i < MAX_THREADS; i++)
for (int j = 0; j < ACTIVE_SPLIT_POINTS_MAX; j++)
lock_destroy(&(SplitPointStack[i][j].lock));
}
- // thread_should_stop() checks whether the thread with a given threadID has
- // been asked to stop, directly or indirectly. This can happen if a beta
- // cutoff has occurred in the thread's currently active split point, or in
- // some ancestor of the current split point.
+ // thread_should_stop() checks whether the thread should stop its search.
+ // This can happen if a beta cutoff has occurred in the thread's currently
+ // active split point, or in some ancestor of the current split point.
- bool thread_should_stop(int threadID) {
+ bool ThreadsManager::thread_should_stop(int threadID) const {
assert(threadID >= 0 && threadID < ActiveThreads);
SplitPoint* sp;
- if (Threads[threadID].stop)
- return true;
- if (ActiveThreads <= 2)
- return false;
- for (sp = Threads[threadID].splitPoint; sp != NULL; sp = sp->parent)
- if (sp->finished)
- {
- Threads[threadID].stop = true;
- return true;
- }
- return false;
+ for (sp = threads[threadID].splitPoint; sp && !sp->stopRequest; sp = sp->parent);
+ return sp != NULL;
}
// threads which are busy searching the split point at the top of "slave"'s
// split point stack (the "helpful master concept" in YBWC terminology).
- bool thread_is_available(int slave, int master) {
+ bool ThreadsManager::thread_is_available(int slave, int master) const {
assert(slave >= 0 && slave < ActiveThreads);
assert(master >= 0 && master < ActiveThreads);
assert(ActiveThreads > 1);
- if (!Threads[slave].idle || slave == master)
+ if (threads[slave].state != THREAD_AVAILABLE || slave == master)
return false;
- if (Threads[slave].activeSplitPoints == 0)
+ // Make a local copy to be sure doesn't change under our feet
+ int localActiveSplitPoints = threads[slave].activeSplitPoints;
+
+ if (localActiveSplitPoints == 0)
// No active split points means that the thread is available as
// a slave for any other thread.
return true;
if (ActiveThreads == 2)
return true;
- // Apply the "helpful master" concept if possible
- if (SplitPointStack[slave][Threads[slave].activeSplitPoints - 1].slaves[master])
+ // Apply the "helpful master" concept if possible. Use localActiveSplitPoints
+ // that is known to be > 0, instead of threads[slave].activeSplitPoints that
+ // could have been set to 0 by another thread leading to an out of bound access.
+ if (SplitPointStack[slave][localActiveSplitPoints - 1].slaves[master])
return true;
return false;
}
- // idle_thread_exists() tries to find an idle thread which is available as
+ // available_thread_exists() tries to find an idle thread which is available as
// a slave for the thread with threadID "master".
- bool idle_thread_exists(int master) {
+ bool ThreadsManager::available_thread_exists(int master) const {
assert(master >= 0 && master < ActiveThreads);
assert(ActiveThreads > 1);
// threads have returned from sp_search_pv (or, equivalently, when
// splitPoint->cpus becomes 0), split() returns true.
- bool split(const Position& p, SearchStack* sstck, int ply,
+ bool ThreadsManager::split(const Position& p, SearchStack* sstck, int ply,
Value* alpha, Value* beta, Value* bestValue, const Value futilityValue,
Depth depth, int* moves, MovePicker* mp, int master, bool pvNode) {
assert(ActiveThreads > 1);
SplitPoint* splitPoint;
- int i;
lock_grab(&MPLock);
// If no other thread is available to help us, or if we have too many
// active split points, don't split.
- if ( !idle_thread_exists(master)
- || Threads[master].activeSplitPoints >= ACTIVE_SPLIT_POINTS_MAX)
+ if ( !available_thread_exists(master)
+ || threads[master].activeSplitPoints >= ACTIVE_SPLIT_POINTS_MAX)
{
lock_release(&MPLock);
return false;
}
// Pick the next available split point object from the split point stack
- splitPoint = SplitPointStack[master] + Threads[master].activeSplitPoints;
- Threads[master].activeSplitPoints++;
+ splitPoint = &SplitPointStack[master][threads[master].activeSplitPoints];
- // Initialize the split point object and copy current position
- splitPoint->parent = Threads[master].splitPoint;
- splitPoint->finished = false;
+ // Initialize the split point object
+ splitPoint->parent = threads[master].splitPoint;
+ splitPoint->stopRequest = false;
splitPoint->ply = ply;
splitPoint->depth = depth;
splitPoint->alpha = pvNode ? *alpha : (*beta - 1);
splitPoint->mp = mp;
splitPoint->moves = *moves;
splitPoint->cpus = 1;
- splitPoint->pos.copy(p);
+ splitPoint->pos = &p;
splitPoint->parentSstack = sstck;
- for (i = 0; i < ActiveThreads; i++)
+ for (int i = 0; i < ActiveThreads; i++)
splitPoint->slaves[i] = 0;
- // Copy the current search stack to the master thread
- memcpy(splitPoint->sstack[master], sstck, (ply+1) * sizeof(SearchStack));
- Threads[master].splitPoint = splitPoint;
+ threads[master].splitPoint = splitPoint;
+ threads[master].activeSplitPoints++;
+
+ // If we are here it means we are not available
+ assert(threads[master].state != THREAD_AVAILABLE);
- // Make copies of the current position and search stack for each thread
- for (i = 0; i < ActiveThreads && splitPoint->cpus < MaxThreadsPerSplitPoint; i++)
+ // Allocate available threads setting state to THREAD_BOOKED
+ for (int i = 0; i < ActiveThreads && splitPoint->cpus < MaxThreadsPerSplitPoint; i++)
if (thread_is_available(i, master))
{
- memcpy(splitPoint->sstack[i], sstck, (ply+1) * sizeof(SearchStack));
- Threads[i].splitPoint = splitPoint;
+ threads[i].state = THREAD_BOOKED;
+ threads[i].splitPoint = splitPoint;
splitPoint->slaves[i] = 1;
splitPoint->cpus++;
}
+ assert(splitPoint->cpus > 1);
+
+ // We can release the lock because slave threads are already booked and master is not available
+ lock_release(&MPLock);
+
// Tell the threads that they have work to do. This will make them leave
- // their idle loop.
- for (i = 0; i < ActiveThreads; i++)
+ // their idle loop. But before copy search stack tail for each thread.
+ for (int i = 0; i < ActiveThreads; i++)
if (i == master || splitPoint->slaves[i])
{
- Threads[i].workIsWaiting = true;
- Threads[i].idle = false;
- Threads[i].stop = false;
- }
+ memcpy(splitPoint->sstack[i] + ply - 1, sstck + ply - 1, 4 * sizeof(SearchStack));
- lock_release(&MPLock);
+ assert(i == master || threads[i].state == THREAD_BOOKED);
+
+ threads[i].state = THREAD_WORKISWAITING; // This makes the slave to exit from idle_loop()
+ }
// Everything is set up. The master thread enters the idle loop, from
- // which it will instantly launch a search, because its workIsWaiting
- // slot is 'true'. We send the split point as a second parameter to the
+ // which it will instantly launch a search, because its state is
+ // THREAD_WORKISWAITING. We send the split point as a second parameter to the
// idle loop, which means that the main thread will return from the idle
// loop when all threads have finished their work at this split point
// (i.e. when splitPoint->cpus == 0).
*beta = splitPoint->beta;
*bestValue = splitPoint->bestValue;
- Threads[master].stop = false;
- Threads[master].idle = false;
- Threads[master].activeSplitPoints--;
- Threads[master].splitPoint = splitPoint->parent;
+ threads[master].activeSplitPoints--;
+ threads[master].splitPoint = splitPoint->parent;
lock_release(&MPLock);
return true;
// wake_sleeping_threads() wakes up all sleeping threads when it is time
// to start a new search from the root.
- void wake_sleeping_threads() {
+ void ThreadsManager::wake_sleeping_threads() {
+
+ assert(AllThreadsShouldSleep);
+ assert(ActiveThreads > 0);
+
+ AllThreadsShouldSleep = false;
- if (ActiveThreads > 1)
+ if (ActiveThreads == 1)
+ return;
+
+ for (int i = 1; i < ActiveThreads; i++)
{
- for (int i = 1; i < ActiveThreads; i++)
- {
- Threads[i].idle = true;
- Threads[i].workIsWaiting = false;
- }
+ assert(threads[i].state == THREAD_SLEEPING);
+
+ threads[i].state = THREAD_AVAILABLE;
+ }
#if !defined(_MSC_VER)
- pthread_mutex_lock(&WaitLock);
- pthread_cond_broadcast(&WaitCond);
- pthread_mutex_unlock(&WaitLock);
+ pthread_mutex_lock(&WaitLock);
+ pthread_cond_broadcast(&WaitCond);
+ pthread_mutex_unlock(&WaitLock);
#else
- for (int i = 1; i < THREAD_MAX; i++)
- SetEvent(SitIdleEvent[i]);
+ for (int i = 1; i < MAX_THREADS; i++)
+ SetEvent(SitIdleEvent[i]);
#endif
+
+ }
+
+
+ // put_threads_to_sleep() makes all the threads go to sleep just before
+ // to leave think(), at the end of the search. Threads should have already
+ // finished the job and should be idle.
+
+ void ThreadsManager::put_threads_to_sleep() {
+
+ assert(!AllThreadsShouldSleep);
+
+ // This makes the threads to go to sleep
+ AllThreadsShouldSleep = true;
+
+ // Wait for the threads to be all sleeping and reset flags
+ // to a known state.
+ for (int i = 1; i < ActiveThreads; i++)
+ {
+ while (threads[i].state != THREAD_SLEEPING);
+
+ // This flag can be in a random state
+ threads[i].printCurrentLineRequest = false;
}
}
+ // print_current_line() prints _once_ the current line of search for a
+ // given thread and then setup the print request for the next thread.
+ // Called when the UCI option UCI_ShowCurrLine is 'true'.
- // init_thread() is the function which is called when a new thread is
- // launched. It simply calls the idle_loop() function with the supplied
- // threadID. There are two versions of this function; one for POSIX
- // threads and one for Windows threads.
+ void ThreadsManager::print_current_line(SearchStack ss[], int ply, int threadID) {
-#if !defined(_MSC_VER)
+ assert(ply >= 0 && ply < PLY_MAX);
+ assert(threadID >= 0 && threadID < ActiveThreads);
- void* init_thread(void *threadID) {
+ if (!threads[threadID].printCurrentLineRequest)
+ return;
- idle_loop(*(int*)threadID, NULL);
- return NULL;
+ // One shot only
+ threads[threadID].printCurrentLineRequest = false;
+
+ if (threads[threadID].state == THREAD_SEARCHING)
+ {
+ lock_grab(&IOLock);
+ cout << "info currline " << (threadID + 1);
+ for (int p = 0; p < ply; p++)
+ cout << " " << ss[p].currentMove;
+
+ cout << endl;
+ lock_release(&IOLock);
+ }
+
+ // Setup print request for the next thread ID
+ if (threadID + 1 < ActiveThreads)
+ threads[threadID + 1].printCurrentLineRequest = true;
}
-#else
- DWORD WINAPI init_thread(LPVOID threadID) {
+ /// The RootMoveList class
- idle_loop(*(int*)threadID, NULL);
- return NULL;
+ // RootMoveList c'tor
+
+ RootMoveList::RootMoveList(Position& pos, Move searchMoves[]) : count(0) {
+
+ SearchStack ss[PLY_MAX_PLUS_2];
+ MoveStack mlist[MaxRootMoves];
+ StateInfo st;
+ bool includeAllMoves = (searchMoves[0] == MOVE_NONE);
+
+ // Generate all legal moves
+ MoveStack* last = generate_moves(pos, mlist);
+
+ // Add each move to the moves[] array
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ {
+ bool includeMove = includeAllMoves;
+
+ for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++)
+ includeMove = (searchMoves[k] == cur->move);
+
+ if (!includeMove)
+ continue;
+
+ // Find a quick score for the move
+ init_ss_array(ss);
+ pos.do_move(cur->move, st);
+ moves[count].move = cur->move;
+ moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0);
+ moves[count].pv[0] = cur->move;
+ moves[count].pv[1] = MOVE_NONE;
+ pos.undo_move(cur->move);
+ count++;
+ }
+ sort();
}
-#endif
-}
+ // RootMoveList simple methods definitions
+
+ void RootMoveList::set_move_nodes(int moveNum, int64_t nodes) {
+
+ moves[moveNum].nodes = nodes;
+ moves[moveNum].cumulativeNodes += nodes;
+ }
+
+ void RootMoveList::set_beta_counters(int moveNum, int64_t our, int64_t their) {
+
+ moves[moveNum].ourBeta = our;
+ moves[moveNum].theirBeta = their;
+ }
+
+ void RootMoveList::set_move_pv(int moveNum, const Move pv[]) {
+
+ int j;
+
+ for (j = 0; pv[j] != MOVE_NONE; j++)
+ moves[moveNum].pv[j] = pv[j];
+
+ moves[moveNum].pv[j] = MOVE_NONE;
+ }
+
+
+ // RootMoveList::sort() sorts the root move list at the beginning of a new
+ // iteration.
+
+ void RootMoveList::sort() {
+
+ sort_multipv(count - 1); // Sort all items
+ }
+
+
+ // RootMoveList::sort_multipv() sorts the first few moves in the root move
+ // list by their scores and depths. It is used to order the different PVs
+ // correctly in MultiPV mode.
+
+ void RootMoveList::sort_multipv(int n) {
+
+ int i,j;
+
+ for (i = 1; i <= n; i++)
+ {
+ RootMove rm = moves[i];
+ for (j = i; j > 0 && moves[j - 1] < rm; j--)
+ moves[j] = moves[j - 1];
+
+ moves[j] = rm;
+ }
+ }
+
+} // namspace
projects / stockfish / blobdiff