X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d19c9a9015423192991319e4e6b910db955c4e8e;hp=4c33d263dc6aa42f2deb812b299bec99a943367d;hb=13d1776a983c8b6b8ee2ed83ef7d2a4a5caf93a9;hpb=9ec12da028948744317db3feaf11e90441e7fe9c
diff --git a/src/search.cpp b/src/search.cpp
index 4c33d263..d19c9a90 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1,17 +1,18 @@
/*
- Glaurung, a UCI chess playing engine.
- Copyright (C) 2004-2008 Tord Romstad
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008 Marco Costalba
- Glaurung is free software: you can redistribute it and/or modify
+ Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-
- Glaurung is distributed in the hope that it will be useful,
+
+ Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
@@ -22,7 +23,6 @@
////
#include
-#include
#include
#include
#include
@@ -51,10 +51,11 @@ namespace {
// root move, we store a score, a node count, and a PV (really a refutation
// in the case of moves which fail low).
- class RootMove {
+ struct RootMove {
- public:
RootMove();
+ bool operator<(const RootMove&); // used to sort
+
Move move;
Value score;
int64_t nodes, cumulativeNodes;
@@ -69,20 +70,19 @@ namespace {
public:
RootMoveList(Position &pos, Move searchMoves[]);
- Move get_move(int moveNum) const;
- Value get_move_score(int moveNum) const;
- void set_move_score(int moveNum, Value score);
- void set_move_nodes(int moveNum, int64_t nodes);
+ inline Move get_move(int moveNum) const;
+ inline Value get_move_score(int moveNum) const;
+ inline void set_move_score(int moveNum, Value score);
+ inline void set_move_nodes(int moveNum, int64_t nodes);
void set_move_pv(int moveNum, const Move pv[]);
- Move get_move_pv(int moveNum, int i) const;
- int64_t get_move_cumulative_nodes(int moveNum);
- int move_count() const;
+ inline Move get_move_pv(int moveNum, int i) const;
+ inline int64_t get_move_cumulative_nodes(int moveNum) const;
+ inline int move_count() const;
Move scan_for_easy_move() const;
- void sort();
+ inline void sort();
void sort_multipv(int n);
private:
- static bool compare_root_moves(const RootMove &rm1, const RootMove &rm2);
static const int MaxRootMoves = 500;
RootMove moves[MaxRootMoves];
int count;
@@ -153,6 +153,12 @@ namespace {
Depth RazorDepth = 4*OnePly;
Value RazorMargin = Value(0x300);
+ // Last seconds noise filtering (LSN)
+ bool UseLSNFiltering = false;
+ bool looseOnTime = false;
+ int LSNTime = 4 * 1000; // In milliseconds
+ Value LSNValue = Value(0x200);
+
// Extensions. Array index 0 is used at non-PV nodes, index 1 at PV nodes.
Depth CheckExtension[2] = {OnePly, OnePly};
Depth SingleReplyExtension[2] = {OnePly / 2, OnePly / 2};
@@ -181,7 +187,7 @@ namespace {
// Time managment variables
int SearchStartTime;
int MaxNodes, MaxDepth;
- int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime;
+ int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime, TimeAdvantage;
Move BestRootMove, PonderMove, EasyMove;
int RootMoveNumber;
bool InfiniteSearch;
@@ -221,7 +227,7 @@ namespace {
/// Functions
- void id_loop(const Position &pos, Move searchMoves[]);
+ Value id_loop(const Position &pos, Move searchMoves[]);
Value root_search(Position &pos, SearchStack ss[], RootMoveList &rml);
Value search_pv(Position &pos, SearchStack ss[], Value alpha, Value beta,
Depth depth, int ply, int threadID);
@@ -240,6 +246,10 @@ namespace {
bool singleReply, bool mateThreat);
bool ok_to_do_nullmove(const Position &pos);
bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d);
+ bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply);
+ bool ok_to_history(const Position &pos, Move m);
+ void update_history(const Position& pos, Move m, Depth depth,
+ Move movesSearched[], int moveCount);
bool fail_high_ply_1();
int current_search_time();
@@ -266,7 +276,7 @@ namespace {
#else
DWORD WINAPI init_thread(LPVOID threadID);
#endif
-
+
}
@@ -292,13 +302,13 @@ History H; // Should be made local?
//// Functions
////
-/// think() is the external interface to Glaurung's search, and is called when
+/// 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()
-void think(const Position &pos, bool infinite, bool ponder, int time,
- int increment, int movesToGo, int maxDepth, int maxNodes,
- int maxTime, Move searchMoves[]) {
+void think(const Position &pos, bool infinite, bool ponder, int side_to_move,
+ int time[], int increment[], int movesToGo, int maxDepth,
+ int maxNodes, int maxTime, Move searchMoves[]) {
// Look for a book move:
if(!infinite && !ponder && get_option_value_bool("OwnBook")) {
@@ -338,7 +348,7 @@ void think(const Position &pos, bool infinite, bool ponder, int time,
TT.set_size(get_option_value_int("Hash"));
if(button_was_pressed("Clear Hash"))
TT.clear();
- PonderingEnabled = get_option_value_int("Ponder");
+ PonderingEnabled = get_option_value_bool("Ponder");
MultiPV = get_option_value_int("MultiPV");
CheckExtension[1] = Depth(get_option_value_int("Check Extension (PV nodes)"));
@@ -353,7 +363,7 @@ void think(const Position &pos, bool infinite, bool ponder, int time,
Depth(get_option_value_int("Pawn Push to 7th Extension (non-PV nodes)"));
PassedPawnExtension[1] =
Depth(get_option_value_int("Passed Pawn Extension (PV nodes)"));
- PassedPawnExtension[0] =
+ PassedPawnExtension[0] =
Depth(get_option_value_int("Passed Pawn Extension (non-PV nodes)"));
PawnEndgameExtension[1] =
Depth(get_option_value_int("Pawn Endgame Extension (PV nodes)"));
@@ -391,26 +401,22 @@ void think(const Position &pos, bool infinite, bool ponder, int time,
RazorDepth = (get_option_value_int("Maximum Razoring Depth") + 1) * OnePly;
RazorMargin = value_from_centipawns(get_option_value_int("Razoring Margin"));
+ UseLSNFiltering = get_option_value_bool("LSN filtering");
+ LSNTime = get_option_value_int("LSN Time Margin (sec)") * 1000;
+ LSNValue = value_from_centipawns(get_option_value_int("LSN Value Margin"));
+
MinimumSplitDepth = get_option_value_int("Minimum Split Depth") * OnePly;
MaxThreadsPerSplitPoint =
get_option_value_int("Maximum Number of Threads per Split Point");
read_weights(pos.side_to_move());
-
+
int newActiveThreads = get_option_value_int("Threads");
if(newActiveThreads != ActiveThreads) {
ActiveThreads = newActiveThreads;
init_eval(ActiveThreads);
}
- // Write information to search log file:
- if(UseLogFile) {
- LogFile << "Searching: " << pos.to_fen() << '\n';
- LogFile << "infinite: " << infinite << " ponder: " << ponder
- << " time: " << time << " increment: " << increment
- << " moves to go: " << movesToGo << '\n';
- }
-
// Wake up sleeping threads:
wake_sleeping_threads();
@@ -418,24 +424,30 @@ void think(const Position &pos, bool infinite, bool ponder, int time,
assert(thread_is_available(i, 0));
// Set thinking time:
+ int myTime = time[side_to_move];
+ int myIncrement = increment[side_to_move];
+ int oppTime = time[1 - side_to_move];
+
+ TimeAdvantage = myTime - oppTime;
+
if(!movesToGo) { // Sudden death time control
if(increment) {
- MaxSearchTime = time / 30 + increment;
- AbsoluteMaxSearchTime = Max(time / 4, increment - 100);
+ MaxSearchTime = myTime / 30 + myIncrement;
+ AbsoluteMaxSearchTime = Max(myTime / 4, myIncrement - 100);
}
else { // Blitz game without increment
- MaxSearchTime = time / 40;
- AbsoluteMaxSearchTime = time / 8;
+ MaxSearchTime = myTime / 40;
+ AbsoluteMaxSearchTime = myTime / 8;
}
}
else { // (x moves) / (y minutes)
if(movesToGo == 1) {
- MaxSearchTime = time / 2;
- AbsoluteMaxSearchTime = Min(time / 2, time - 500);
+ MaxSearchTime = myTime / 2;
+ AbsoluteMaxSearchTime = Min(myTime / 2, myTime - 500);
}
else {
- MaxSearchTime = time / Min(movesToGo, 20);
- AbsoluteMaxSearchTime = Min((4 * time) / movesToGo, time / 3);
+ MaxSearchTime = myTime / Min(movesToGo, 20);
+ AbsoluteMaxSearchTime = Min((4 * myTime) / movesToGo, myTime / 3);
}
}
if(PonderingEnabled) {
@@ -456,13 +468,36 @@ void think(const Position &pos, bool infinite, bool ponder, int time,
else
NodesBetweenPolls = 30000;
+
+ // Write information to search log file:
+ if(UseLogFile) {
+ LogFile << "Searching: " << pos.to_fen() << '\n';
+ LogFile << "infinite: " << infinite << " ponder: " << ponder
+ << " time: " << myTime << " increment: " << myIncrement
+ << " moves to go: " << movesToGo << '\n';
+ }
+
// We're ready to start thinking. Call the iterative deepening loop
// function:
- id_loop(pos, searchMoves);
+ if (!looseOnTime)
+ {
+ Value v = id_loop(pos, searchMoves);
+ looseOnTime = ( UseLSNFiltering
+ && myTime < LSNTime
+ && myIncrement == 0
+ && v < -LSNValue);
+ }
+ else
+ {
+ looseOnTime = false; // reset for next match
+ while (SearchStartTime + myTime + 1000 > get_system_time())
+ ; // wait here
+ id_loop(pos, searchMoves); // to fail gracefully
+ }
if(UseLogFile)
LogFile.close();
-
+
if(Quit) {
OpeningBook.close();
stop_threads();
@@ -492,7 +527,7 @@ void init_threads() {
lock_init(&IOLock, NULL);
init_split_point_stack();
-
+
#if !defined(_MSC_VER)
pthread_mutex_init(&WaitLock, NULL);
pthread_cond_init(&WaitCond, NULL);
@@ -560,7 +595,7 @@ namespace {
// been consumed, the user stops the search, or the maximum search depth is
// reached.
- void id_loop(const Position &pos, Move searchMoves[]) {
+ Value id_loop(const Position &pos, Move searchMoves[]) {
Position p(pos);
SearchStack ss[PLY_MAX_PLUS_2];
@@ -631,6 +666,10 @@ namespace {
BestMoveChangesByIteration[Iteration] * (MaxSearchTime / 2) +
BestMoveChangesByIteration[Iteration-1] * (MaxSearchTime / 3);
+ // If we need some more and we are in time advantage take it.
+ if (ExtraSearchTime > 0 && TimeAdvantage > 2 * MaxSearchTime)
+ ExtraSearchTime += MaxSearchTime / 2;
+
// Stop search if most of MaxSearchTime is consumed at the end of the
// iteration. We probably don't have enough time to search the first
// move at the next iteration anyway.
@@ -645,7 +684,7 @@ namespace {
}
}
- // Write PV to transposition table, in case the relevant entries have
+ // Write PV to transposition table, in case the relevant entries have
// been overwritten during the search:
TT.insert_pv(p, ss[0].pv);
@@ -680,6 +719,7 @@ namespace {
LogFile << "Ponder move: " << move_to_san(p, ss[0].pv[1]) << '\n';
LogFile << std::endl;
}
+ return rml.get_move_score(0);
}
@@ -712,7 +752,7 @@ namespace {
if(current_search_time() >= 1000)
std::cout << "info currmove " << move
<< " currmovenumber " << i + 1 << std::endl;
-
+
// Decide search depth for this move:
ext = extension(pos, move, true, pos.move_is_check(move), false, false);
newDepth = (Iteration-2)*OnePly + ext + InitialDepth;
@@ -734,7 +774,7 @@ namespace {
else {
value = -search(pos, ss, -alpha, newDepth, 1, true, 0);
if(value > alpha) {
- // Fail high! Set the boolean variable FailHigh to true, and
+ // Fail high! Set the boolean variable FailHigh to true, and
// re-search the move with a big window. The variable FailHigh is
// used for time managment: We try to avoid aborting the search
// prematurely during a fail high research.
@@ -753,7 +793,7 @@ namespace {
if(AbortSearch)
break;
- // Remember the node count for this move. The node counts are used to
+ // Remember the node count for this move. The node counts are used to
// sort the root moves at the next iteration.
rml.set_move_nodes(i, nodes_searched() - nodes);
@@ -770,7 +810,7 @@ namespace {
rml.set_move_pv(i, ss[0].pv);
if(MultiPV == 1) {
- // We record how often the best move has been changed in each
+ // 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)
@@ -826,6 +866,7 @@ namespace {
Value search_pv(Position &pos, SearchStack ss[], Value alpha, Value beta,
Depth depth, int ply, int threadID) {
+
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta > alpha && beta <= VALUE_INFINITE);
assert(ply >= 0 && ply < PLY_MAX);
@@ -837,185 +878,194 @@ namespace {
// an instant draw, maximum ply reached, etc.
Value oldAlpha = alpha;
- if(AbortSearch || thread_should_stop(threadID))
- return Value(0);
+ if (AbortSearch || thread_should_stop(threadID))
+ return Value(0);
- if(depth < OnePly)
- return qsearch(pos, ss, alpha, beta, Depth(0), ply, threadID);
+ if (depth < OnePly)
+ return qsearch(pos, ss, alpha, beta, Depth(0), ply, threadID);
init_node(pos, ss, ply, threadID);
- if(pos.is_draw())
- return VALUE_DRAW;
+ if (pos.is_draw())
+ return VALUE_DRAW;
- if(ply >= PLY_MAX - 1)
- return evaluate(pos, ei, threadID);
+ if (ply >= PLY_MAX - 1)
+ return evaluate(pos, ei, threadID);
// Mate distance pruning
alpha = Max(value_mated_in(ply), alpha);
beta = Min(value_mate_in(ply+1), beta);
- if(alpha >= beta)
- return alpha;
+ if (alpha >= beta)
+ return alpha;
// Transposition table lookup. At PV nodes, we don't use the TT for
- // pruning, but only for move ordering.
- Value ttValue;
- Depth ttDepth;
- Move ttMove = MOVE_NONE;
- ValueType ttValueType;
-
- TT.retrieve(pos, &ttValue, &ttDepth, &ttMove, &ttValueType);
-
- // Internal iterative deepening.
- if(UseIIDAtPVNodes && ttMove == MOVE_NONE && depth >= 5*OnePly) {
- search_pv(pos, ss, alpha, beta, depth-2*OnePly, ply, threadID);
- ttMove = ss[ply].pv[ply];
+ // pruning, but only for move ordering.
+ const TTEntry* tte = TT.retrieve(pos);
+
+ Move ttMove = (tte ? tte->move() : MOVE_NONE);
+
+ // Go with internal iterative deepening if we don't have a TT move
+ if (UseIIDAtPVNodes && ttMove == MOVE_NONE && depth >= 5*OnePly)
+ {
+ search_pv(pos, ss, alpha, beta, depth-2*OnePly, ply, threadID);
+ ttMove = ss[ply].pv[ply];
}
// Initialize a MovePicker object for the current position, and prepare
// to search all moves:
MovePicker mp = MovePicker(pos, true, ttMove, ss[ply].mateKiller,
ss[ply].killer1, ss[ply].killer2, depth);
+
Move move, movesSearched[256];
int moveCount = 0;
Value value, bestValue = -VALUE_INFINITE;
Bitboard dcCandidates = mp.discovered_check_candidates();
- bool mateThreat =
- MateThreatExtension[1] > Depth(0)
- && pos.has_mate_threat(opposite_color(pos.side_to_move()));
+ bool mateThreat = MateThreatExtension[1] > Depth(0)
+ && pos.has_mate_threat(opposite_color(pos.side_to_move()));
// Loop through all legal moves until no moves remain or a beta cutoff
// occurs.
- while(alpha < beta && !thread_should_stop(threadID)
- && (move = mp.get_next_move()) != MOVE_NONE) {
- UndoInfo u;
- Depth ext, newDepth;
+ while ( alpha < beta
+ && (move = mp.get_next_move()) != MOVE_NONE
+ && !thread_should_stop(threadID))
+ {
+ assert(move_is_ok(move));
+
+ bool fewMoves = (depth <= OnePly && mp.number_of_moves() < 4);
bool singleReply = (pos.is_check() && mp.number_of_moves() == 1);
bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
bool moveIsPassedPawnPush = pos.move_is_passed_pawn_push(move);
-
- assert(move_is_ok(move));
+
movesSearched[moveCount++] = ss[ply].currentMove = move;
- ss[ply].currentMoveCaptureValue = move_is_ep(move)?
+ ss[ply].currentMoveCaptureValue = move_is_ep(move) ?
PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move));
- // Decide the new search depth.
- ext = extension(pos, move, true, moveIsCheck, singleReply, mateThreat);
- newDepth = depth - OnePly + ext;
+ // Decide the new search depth
+ Depth ext = extension(pos, move, true, moveIsCheck, singleReply || fewMoves, mateThreat);
+ Depth newDepth = depth - OnePly + ext;
- // Make and search the move.
+ // Make and search the move
+ UndoInfo u;
pos.do_move(move, u, dcCandidates);
-
- if(moveCount == 1)
- value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);
- else {
- if(depth >= 2*OnePly && ext == Depth(0) && moveCount >= LMRPVMoves
- && !moveIsCapture && !move_promotion(move)
- && !moveIsPassedPawnPush && !move_is_castle(move)
- && move != ss[ply].killer1 && move != ss[ply].killer2) {
- ss[ply].reduction = OnePly;
- value = -search(pos, ss, -alpha, newDepth-OnePly, ply+1, true,
- threadID);
+
+ if (moveCount == 1) // The first move in list is the PV
+ value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);
+ 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 >= 2*OnePly
+ && ext == Depth(0)
+ && moveCount >= LMRPVMoves
+ && !moveIsCapture
+ && !move_promotion(move)
+ && !moveIsPassedPawnPush
+ && !move_is_castle(move)
+ && move != ss[ply].killer1
+ && move != ss[ply].killer2)
+ {
+ ss[ply].reduction = OnePly;
+ value = -search(pos, ss, -alpha, newDepth-OnePly, ply+1, true, threadID);
}
- else value = alpha + 1;
- if(value > alpha) {
- ss[ply].reduction = Depth(0);
- value = -search(pos, ss, -alpha, newDepth, ply+1, true, threadID);
- if(value > alpha && value < beta) {
- if(ply == 1 && RootMoveNumber == 1)
- // 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.
- Threads[threadID].failHighPly1 = true;
- value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1,
- threadID);
- Threads[threadID].failHighPly1 = false;
+ else
+ value = alpha + 1; // Just to trigger next condition
+
+ if (value > alpha) // Go with full depth 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, u);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
-
+
// New best move?
- if(value > bestValue) {
- bestValue = value;
- if(value > alpha) {
- alpha = value;
- update_pv(ss, ply);
- 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(Iteration >= 2 &&
- -value <= ValueByIteration[Iteration-1] - ProblemMargin)
- Problem = true;
+ if (value > bestValue)
+ {
+ bestValue = value;
+ if (value > alpha)
+ {
+ alpha = value;
+ update_pv(ss, ply);
+ 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 (Iteration >= 2 && -value <= ValueByIteration[Iteration-1] - ProblemMargin)
+ Problem = true;
}
// Split?
- if(ActiveThreads > 1 && bestValue < beta && depth >= MinimumSplitDepth
- && Iteration <= 99 && idle_thread_exists(threadID)
- && !AbortSearch && !thread_should_stop(threadID)
- && split(pos, ss, ply, &alpha, &beta, &bestValue, depth,
- &moveCount, &mp, dcCandidates, threadID, true))
- break;
+ if ( ActiveThreads > 1
+ && bestValue < beta
+ && depth >= MinimumSplitDepth
+ && Iteration <= 99
+ && idle_thread_exists(threadID)
+ && !AbortSearch
+ && !thread_should_stop(threadID)
+ && split(pos, ss, ply, &alpha, &beta, &bestValue, depth,
+ &moveCount, &mp, dcCandidates, threadID, true))
+ break;
}
// All legal moves have been searched. A special case: If there were
// no legal moves, it must be mate or stalemate:
- if(moveCount == 0) {
- if(pos.is_check())
- return value_mated_in(ply);
- else
- return VALUE_DRAW;
- }
+ if (moveCount == 0)
+ return (pos.is_check() ? value_mated_in(ply) : VALUE_DRAW);
+
+ // If the search is not aborted, update the transposition table,
+ // history counters, and killer moves.
+ if (AbortSearch || thread_should_stop(threadID))
+ return bestValue;
+
+ if (bestValue <= oldAlpha)
+ TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE, VALUE_TYPE_UPPER);
- // If the search is not aborted, update the transposition table,
- // history counters, and killer moves. This code is somewhat messy,
- // and definitely needs to be cleaned up. FIXME
- if(!AbortSearch && !thread_should_stop(threadID)) {
- if(bestValue <= oldAlpha)
- TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE,
- VALUE_TYPE_UPPER);
- else if(bestValue >= beta) {
+ else if (bestValue >= beta)
+ {
Move m = ss[ply].pv[ply];
- if(pos.square_is_empty(move_to(m)) && !move_promotion(m) &&
- !move_is_ep(m)) {
- for(int i = 0; i < moveCount - 1; i++)
- if(pos.square_is_empty(move_to(movesSearched[i]))
- && !move_promotion(movesSearched[i])
- && !move_is_ep(movesSearched[i]))
- H.failure(pos.piece_on(move_from(movesSearched[i])),
- movesSearched[i]);
-
- H.success(pos.piece_on(move_from(m)), m, depth);
-
- if(m != ss[ply].killer1) {
- ss[ply].killer2 = ss[ply].killer1;
- ss[ply].killer1 = m;
- }
+ if (ok_to_history(pos, m)) // Only non capture moves are considered
+ {
+ update_history(pos, m, depth, movesSearched, moveCount);
+ if (m != ss[ply].killer1)
+ {
+ ss[ply].killer2 = ss[ply].killer1;
+ ss[ply].killer1 = m;
+ }
}
TT.store(pos, value_to_tt(bestValue, ply), depth, m, VALUE_TYPE_LOWER);
- }
- else
- TT.store(pos, value_to_tt(bestValue, ply), depth, ss[ply].pv[ply],
- VALUE_TYPE_EXACT);
}
+ else
+ TT.store(pos, value_to_tt(bestValue, ply), depth, ss[ply].pv[ply], VALUE_TYPE_EXACT);
return bestValue;
}
-
+
// search() is the search function for zero-width nodes.
Value search(Position &pos, SearchStack ss[], Value beta, Depth depth,
int ply, bool allowNullmove, int threadID) {
+
assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
assert(ply >= 0 && ply < PLY_MAX);
assert(threadID >= 0 && threadID < ActiveThreads);
@@ -1024,231 +1074,241 @@ namespace {
// Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
- if(AbortSearch || thread_should_stop(threadID))
- return Value(0);
+ if (AbortSearch || thread_should_stop(threadID))
+ return Value(0);
- if(depth < OnePly)
- return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
+ if (depth < OnePly)
+ return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
init_node(pos, ss, ply, threadID);
- if(pos.is_draw())
- return VALUE_DRAW;
+ if (pos.is_draw())
+ return VALUE_DRAW;
- if(ply >= PLY_MAX - 1)
- return evaluate(pos, ei, threadID);
+ if (ply >= PLY_MAX - 1)
+ return evaluate(pos, ei, threadID);
// Mate distance pruning
- if(value_mated_in(ply) >= beta)
- return beta;
- if(value_mate_in(ply+1) < beta)
- return beta-1;
+ if (value_mated_in(ply) >= beta)
+ return beta;
+
+ if (value_mate_in(ply + 1) < beta)
+ return beta - 1;
// Transposition table lookup
- bool ttFound;
- Value ttValue;
- Depth ttDepth;
- Move ttMove = MOVE_NONE;
- ValueType ttValueType;
-
- ttFound = TT.retrieve(pos, &ttValue, &ttDepth, &ttMove, &ttValueType);
- if(ttFound) {
- ttValue = value_from_tt(ttValue, ply);
- if(ttDepth >= depth
- || ttValue >= Max(value_mate_in(100), beta)
- || ttValue < Min(value_mated_in(100), beta)) {
- if((is_lower_bound(ttValueType) && ttValue >= beta) ||
- (is_upper_bound(ttValueType) && ttValue < beta)) {
- ss[ply].currentMove = ttMove;
- return ttValue;
- }
- }
+ const TTEntry* tte = TT.retrieve(pos);
+
+ Move ttMove = (tte ? tte->move() : MOVE_NONE);
+
+ if (tte && ok_to_use_TT(tte, depth, beta, ply))
+ {
+ ss[ply].currentMove = ttMove; // can be MOVE_NONE ?
+ return value_from_tt(tte->value(), ply);
}
Value approximateEval = quick_evaluate(pos);
bool mateThreat = false;
// Null move search
- if(!pos.is_check() && allowNullmove && ok_to_do_nullmove(pos)
- && approximateEval >= beta - NullMoveMargin) {
- UndoInfo u;
- Value nullValue;
-
- ss[ply].currentMove = MOVE_NULL;
- pos.do_null_move(u);
- nullValue = -search(pos, ss, -(beta-1), depth-4*OnePly, ply+1, false,
- threadID);
- pos.undo_null_move(u);
-
- if(nullValue >= beta) {
- if(depth >= 6 * OnePly) { // Do zugzwang verification search
- Value v = search(pos, ss, beta, depth-5*OnePly, ply, false, threadID);
- if(v >= beta)
- return beta;
+ if ( allowNullmove
+ && !pos.is_check()
+ && ok_to_do_nullmove(pos)
+ && approximateEval >= beta - NullMoveMargin)
+ {
+ ss[ply].currentMove = MOVE_NULL;
+
+ UndoInfo u;
+ pos.do_null_move(u);
+ Value nullValue = -search(pos, ss, -(beta-1), depth-4*OnePly, ply+1, false, threadID);
+ pos.undo_null_move(u);
+
+ if (nullValue >= beta)
+ {
+ if (depth < 6 * OnePly)
+ return beta;
+
+ // Do zugzwang verification search
+ Value v = search(pos, ss, beta, depth-5*OnePly, ply, false, threadID);
+ if (v >= beta)
+ return beta;
+ } else {
+ // The null move failed low, which means that we may be faced with
+ // some kind of threat. If the previous move was reduced, check if
+ // the move that refuted the null move was somehow connected to the
+ // move which was reduced. If a connection is found, return a fail
+ // low score (which will cause the reduced move to fail high in the
+ // parent node, which will trigger a re-search with full depth).
+ if (nullValue == value_mated_in(ply + 2))
+ mateThreat = true;
+
+ ss[ply].threatMove = ss[ply + 1].currentMove;
+ if ( depth < ThreatDepth
+ && ss[ply - 1].reduction
+ && connected_moves(pos, ss[ply - 1].currentMove, ss[ply].threatMove))
+ return beta - 1;
}
- else
- return beta;
- }
- else {
- // The null move failed low, which means that we may be faced with
- // some kind of threat. If the previous move was reduced, check if
- // the move that refuted the null move was somehow connected to the
- // move which was reduced. If a connection is found, return a fail
- // low score (which will cause the reduced move to fail high in the
- // parent node, which will trigger a re-search with full depth).
- if(nullValue == value_mated_in(ply+2))
- mateThreat = true;
- ss[ply].threatMove = ss[ply+1].currentMove;
- if(depth < ThreatDepth && ss[ply-1].reduction &&
- connected_moves(pos, ss[ply-1].currentMove, ss[ply].threatMove))
- return beta - 1;
- }
}
- // Razoring:
- else if(depth < RazorDepth && approximateEval < beta - RazorMargin &&
- evaluate(pos, ei, threadID) < beta - RazorMargin) {
- Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
- if(v < beta)
- return v;
+ // Null move search not allowed, try razoring
+ else if ( (approximateEval < beta - RazorMargin && depth < RazorDepth)
+ ||(approximateEval < beta - PawnValueMidgame && depth <= OnePly))
+ {
+ Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
+ if (v < beta)
+ return v;
}
- // Internal iterative deepening
- if(UseIIDAtNonPVNodes && ttMove == MOVE_NONE && depth >= 8*OnePly &&
- evaluate(pos, ei, threadID) >= beta - IIDMargin) {
- search(pos, ss, beta, Min(depth/2, depth-2*OnePly), ply, false, threadID);
- ttMove = ss[ply].pv[ply];
+ // Go with internal iterative deepening if we don't have a TT move
+ if (UseIIDAtNonPVNodes && ttMove == MOVE_NONE && depth >= 8*OnePly &&
+ evaluate(pos, ei, threadID) >= beta - IIDMargin)
+ {
+ search(pos, ss, beta, Min(depth/2, depth-2*OnePly), ply, false, threadID);
+ ttMove = ss[ply].pv[ply];
}
// Initialize a MovePicker object for the current position, and prepare
// to search all moves:
MovePicker mp = MovePicker(pos, false, ttMove, ss[ply].mateKiller,
ss[ply].killer1, ss[ply].killer2, depth);
+
Move move, movesSearched[256];
int moveCount = 0;
- Value value, bestValue = -VALUE_INFINITE, futilityValue = VALUE_NONE;
+ Value value, bestValue = -VALUE_INFINITE;
Bitboard dcCandidates = mp.discovered_check_candidates();
+ Value futilityValue = VALUE_NONE;
bool isCheck = pos.is_check();
- bool useFutilityPruning =
- UseFutilityPruning && depth < SelectiveDepth && !isCheck;
+ bool useFutilityPruning = UseFutilityPruning
+ && depth < SelectiveDepth
+ && !isCheck;
// Loop through all legal moves until no moves remain or a beta cutoff
// occurs.
- while(bestValue < beta && !thread_should_stop(threadID)
- && (move = mp.get_next_move()) != MOVE_NONE) {
- UndoInfo u;
- Depth ext, newDepth;
+ while ( bestValue < beta
+ && (move = mp.get_next_move()) != MOVE_NONE
+ && !thread_should_stop(threadID))
+ {
+ assert(move_is_ok(move));
+
bool singleReply = (isCheck && mp.number_of_moves() == 1);
bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
bool moveIsPassedPawnPush = pos.move_is_passed_pawn_push(move);
- assert(move_is_ok(move));
movesSearched[moveCount++] = ss[ply].currentMove = move;
- // Decide the new search depth.
- ext = extension(pos, move, false, moveIsCheck, singleReply, mateThreat);
- newDepth = depth - OnePly + ext;
+ // Decide the new search depth
+ Depth ext = extension(pos, move, false, moveIsCheck, singleReply, mateThreat);
+ Depth newDepth = depth - OnePly + ext;
// Futility pruning
- if(useFutilityPruning && ext == Depth(0) && !moveIsCapture &&
- !moveIsPassedPawnPush && !move_promotion(move)) {
-
- if(moveCount >= 2 + int(depth)
- && ok_to_prune(pos, move, ss[ply].threatMove, depth))
- continue;
-
- if(depth < 3 * OnePly && approximateEval < beta) {
- if(futilityValue == VALUE_NONE)
- futilityValue = evaluate(pos, ei, threadID)
- + ((depth < 2 * OnePly)? FutilityMargin1 : FutilityMargin2);
- if(futilityValue < beta) {
- if(futilityValue > bestValue)
- bestValue = futilityValue;
- continue;
+ if ( useFutilityPruning
+ && ext == Depth(0)
+ && !moveIsCapture
+ && !moveIsPassedPawnPush
+ && !move_promotion(move))
+ {
+ if ( moveCount >= 2 + int(depth)
+ && ok_to_prune(pos, move, ss[ply].threatMove, depth))
+ continue;
+
+ if (depth < 3 * OnePly && approximateEval < beta)
+ {
+ if (futilityValue == VALUE_NONE)
+ futilityValue = evaluate(pos, ei, threadID)
+ + (depth < 2 * OnePly ? FutilityMargin1 : FutilityMargin2);
+
+ if (futilityValue < beta)
+ {
+ if (futilityValue > bestValue)
+ bestValue = futilityValue;
+ continue;
+ }
}
- }
}
- // Make and search the move.
+ // Make and search the move
+ UndoInfo u;
pos.do_move(move, u, dcCandidates);
-
- if(depth >= 2*OnePly && ext == Depth(0) && moveCount >= LMRNonPVMoves
- && !moveIsCapture && !move_promotion(move) && !moveIsPassedPawnPush
- && !move_is_castle(move)
- && move != ss[ply].killer1 && move != ss[ply].killer2) {
- ss[ply].reduction = OnePly;
- value = -search(pos, ss, -(beta-1), newDepth-OnePly, ply+1, true,
- threadID);
+
+ // Try to reduce non-pv search depth by one ply if move seems not problematic,
+ // if the move fails high will be re-searched at full depth.
+ if ( depth >= 2*OnePly
+ && ext == Depth(0)
+ && moveCount >= LMRNonPVMoves
+ && !moveIsCapture
+ && !move_promotion(move)
+ && !moveIsPassedPawnPush
+ && !move_is_castle(move)
+ && move != ss[ply].killer1
+ && move != ss[ply].killer2)
+ {
+ ss[ply].reduction = OnePly;
+ value = -search(pos, ss, -(beta-1), newDepth-OnePly, ply+1, true, threadID);
}
else
- value = beta;
- if(value >= beta) {
- ss[ply].reduction = Depth(0);
- value = -search(pos, ss, -(beta-1), newDepth, ply+1, true, threadID);
+ value = beta; // Just to trigger next condition
+
+ if (value >= beta) // Go with full depth non-pv search
+ {
+ ss[ply].reduction = Depth(0);
+ value = -search(pos, ss, -(beta-1), newDepth, ply+1, true, threadID);
}
pos.undo_move(move, u);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
-
+
// New best move?
- if(value > bestValue) {
+ if (value > bestValue)
+ {
bestValue = value;
- if(value >= beta)
- update_pv(ss, ply);
- if(value == value_mate_in(ply + 1))
- ss[ply].mateKiller = move;
+ if (value >= beta)
+ update_pv(ss, ply);
+
+ if (value == value_mate_in(ply + 1))
+ ss[ply].mateKiller = move;
}
// Split?
- if(ActiveThreads > 1 && bestValue < beta && depth >= MinimumSplitDepth
- && Iteration <= 99 && idle_thread_exists(threadID)
- && !AbortSearch && !thread_should_stop(threadID)
- && split(pos, ss, ply, &beta, &beta, &bestValue, depth, &moveCount,
- &mp, dcCandidates, threadID, false))
+ if ( ActiveThreads > 1
+ && bestValue < beta
+ && depth >= MinimumSplitDepth
+ && Iteration <= 99
+ && idle_thread_exists(threadID)
+ && !AbortSearch
+ && !thread_should_stop(threadID)
+ && split(pos, ss, ply, &beta, &beta, &bestValue, depth, &moveCount,
+ &mp, dcCandidates, threadID, false))
break;
}
// All legal moves have been searched. A special case: If there were
// no legal moves, it must be mate or stalemate:
- if(moveCount == 0) {
- if(pos.is_check())
- return value_mated_in(ply);
- else
- return VALUE_DRAW;
- }
+ if (moveCount == 0)
+ return (pos.is_check() ? value_mated_in(ply) : VALUE_DRAW);
// If the search is not aborted, update the transposition table,
- // history counters, and killer moves. This code is somewhat messy,
- // and definitely needs to be cleaned up. FIXME
- if(!AbortSearch && !thread_should_stop(threadID)) {
- if(bestValue < beta)
- TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE,
- VALUE_TYPE_UPPER);
- else {
+ // history counters, and killer moves.
+ if (AbortSearch || thread_should_stop(threadID))
+ return bestValue;
+
+ if (bestValue < beta)
+ TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE, VALUE_TYPE_UPPER);
+ else
+ {
Move m = ss[ply].pv[ply];
-
- if(pos.square_is_empty(move_to(m)) && !move_promotion(m) &&
- !move_is_ep(m)) {
- for(int i = 0; i < moveCount - 1; i++)
- if(pos.square_is_empty(move_to(movesSearched[i]))
- && !move_promotion(movesSearched[i])
- && !move_is_ep(movesSearched[i]))
- H.failure(pos.piece_on(move_from(movesSearched[i])),
- movesSearched[i]);
- H.success(pos.piece_on(move_from(m)), m, depth);
-
- if(m != ss[ply].killer1) {
- ss[ply].killer2 = ss[ply].killer1;
- ss[ply].killer1 = m;
- }
+ if (ok_to_history(pos, m)) // Only non capture moves are considered
+ {
+ update_history(pos, m, depth, movesSearched, moveCount);
+ if (m != ss[ply].killer1)
+ {
+ ss[ply].killer2 = ss[ply].killer1;
+ ss[ply].killer1 = m;
+ }
}
TT.store(pos, value_to_tt(bestValue, ply), depth, m, VALUE_TYPE_LOWER);
- }
}
-
return bestValue;
}
-
+
// qsearch() is the quiescence search function, which is called by the main
// search function when the remaining depth is zero (or, to be more precise,
@@ -1256,8 +1316,6 @@ namespace {
Value qsearch(Position &pos, SearchStack ss[], Value alpha, Value beta,
Depth depth, int ply, int threadID) {
- Value staticValue, bestValue, value;
- EvalInfo ei;
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
@@ -1265,32 +1323,38 @@ namespace {
assert(ply >= 0 && ply < PLY_MAX);
assert(threadID >= 0 && threadID < ActiveThreads);
- // Initialize, and make an early exit in case of an aborted search,
+ EvalInfo ei;
+
+ // Initialize, and make an early exit in case of an aborted search,
// an instant draw, maximum ply reached, etc.
- if(AbortSearch || thread_should_stop(threadID))
- return Value(0);
+ if (AbortSearch || thread_should_stop(threadID))
+ return Value(0);
init_node(pos, ss, ply, threadID);
- if(pos.is_draw())
- return VALUE_DRAW;
+ if (pos.is_draw())
+ return VALUE_DRAW;
+
+ // Transposition table lookup
+ const TTEntry* tte = TT.retrieve(pos);
+ if (tte && ok_to_use_TT(tte, depth, beta, ply))
+ return value_from_tt(tte->value(), ply);
// Evaluate the position statically:
- staticValue = evaluate(pos, ei, threadID);
+ Value staticValue = evaluate(pos, ei, threadID);
- if(ply == PLY_MAX - 1) return staticValue;
+ if (ply == PLY_MAX - 1)
+ return staticValue;
// Initialize "stand pat score", and return it immediately if it is
// at least beta.
- if(pos.is_check())
- bestValue = -VALUE_INFINITE;
- else {
- bestValue = staticValue;
- if(bestValue >= beta)
+ Value bestValue = (pos.is_check() ? -VALUE_INFINITE : staticValue);
+
+ if (bestValue >= beta)
return bestValue;
- if(bestValue > alpha)
+
+ if (bestValue > alpha)
alpha = bestValue;
- }
// Initialize a MovePicker object for the current position, and prepare
// to search the moves. Because the depth is <= 0 here, only captures,
@@ -1302,67 +1366,80 @@ namespace {
Bitboard dcCandidates = mp.discovered_check_candidates();
bool isCheck = pos.is_check();
- // Loop through the moves until no moves remain or a beta cutoff
+ // Loop through the moves until no moves remain or a beta cutoff
// occurs.
- while(alpha < beta && ((move = mp.get_next_move()) != MOVE_NONE)) {
- UndoInfo u;
+ while ( alpha < beta
+ && (move = mp.get_next_move()) != MOVE_NONE)
+ {
+ assert(move_is_ok(move));
+
bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsPassedPawnPush = pos.move_is_passed_pawn_push(move);
- assert(move_is_ok(move));
-
moveCount++;
ss[ply].currentMove = move;
// Futility pruning
- if(UseQSearchFutilityPruning && !isCheck && !moveIsCheck &&
- !move_promotion(move) && !moveIsPassedPawnPush &&
- beta - alpha == 1 &&
- pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame) {
- Value futilityValue =
- staticValue
- + Max(pos.midgame_value_of_piece_on(move_to(move)),
- pos.endgame_value_of_piece_on(move_to(move)))
- + FutilityMargin0
- + ei.futilityMargin;
- if(futilityValue < alpha) {
- if(futilityValue > bestValue)
- bestValue = futilityValue;
- continue;
- }
+ if ( UseQSearchFutilityPruning
+ && !isCheck
+ && !moveIsCheck
+ && !move_promotion(move)
+ && !moveIsPassedPawnPush
+ && beta - alpha == 1
+ && pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame)
+ {
+ Value futilityValue = staticValue
+ + Max(pos.midgame_value_of_piece_on(move_to(move)),
+ pos.endgame_value_of_piece_on(move_to(move)))
+ + FutilityMargin0
+ + ei.futilityMargin;
+
+ if (futilityValue < alpha)
+ {
+ if (futilityValue > bestValue)
+ bestValue = futilityValue;
+ continue;
+ }
}
// Don't search captures and checks with negative SEE values.
- if(!isCheck && !move_promotion(move) &&
- pos.midgame_value_of_piece_on(move_from(move)) >
- pos.midgame_value_of_piece_on(move_to(move)) &&
- pos.see(move) < 0)
- continue;
+ if ( !isCheck
+ && !move_promotion(move)
+ && (pos.midgame_value_of_piece_on(move_from(move)) >
+ pos.midgame_value_of_piece_on(move_to(move)))
+ && pos.see(move) < 0)
+ continue;
// Make and search the move.
+ UndoInfo u;
pos.do_move(move, u, dcCandidates);
- value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
+ Value value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
pos.undo_move(move, u);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
// New best move?
- if(value > bestValue) {
- bestValue = value;
- if(value > alpha) {
- alpha = value;
- update_pv(ss, ply);
- }
- }
+ if (value > bestValue)
+ {
+ bestValue = value;
+ if (value > alpha)
+ {
+ alpha = value;
+ update_pv(ss, ply);
+ }
+ }
}
// All legal moves have been searched. A special case: If we're in check
- // and no legal moves were found, it is checkmate:
- if(pos.is_check() && moveCount == 0) // Mate!
- return value_mated_in(ply);
+ // and no legal moves were found, it is checkmate:
+ if (pos.is_check() && moveCount == 0) // Mate!
+ return value_mated_in(ply);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
+ // Update transposition table
+ TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE, VALUE_TYPE_EXACT);
+
return bestValue;
}
@@ -1374,82 +1451,97 @@ namespace {
// splitting, we don't have to repeat all this work in sp_search(). 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.
-
+
void sp_search(SplitPoint *sp, int threadID) {
+
assert(threadID >= 0 && threadID < ActiveThreads);
assert(ActiveThreads > 1);
-
+
Position pos = Position(sp->pos);
SearchStack *ss = sp->sstack[threadID];
Value value;
Move move;
- int moveCount = sp->moves;
bool isCheck = pos.is_check();
- bool useFutilityPruning =
- UseFutilityPruning && sp->depth < SelectiveDepth && !isCheck;
+ bool useFutilityPruning = UseFutilityPruning
+ && sp->depth < SelectiveDepth
+ && !isCheck;
+
+ while ( sp->bestValue < sp->beta
+ && !thread_should_stop(threadID)
+ && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE)
+ {
+ assert(move_is_ok(move));
- while(sp->bestValue < sp->beta && !thread_should_stop(threadID)
- && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE) {
- UndoInfo u;
- Depth ext, newDepth;
bool moveIsCheck = pos.move_is_check(move, sp->dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
bool moveIsPassedPawnPush = pos.move_is_passed_pawn_push(move);
- assert(move_is_ok(move));
-
lock_grab(&(sp->lock));
- sp->moves++;
- moveCount = sp->moves;
+ int moveCount = ++sp->moves;
lock_release(&(sp->lock));
ss[sp->ply].currentMove = move;
// Decide the new search depth.
- ext = extension(pos, move, false, moveIsCheck, false, false);
- newDepth = sp->depth - OnePly + ext;
+ Depth ext = extension(pos, move, false, moveIsCheck, false, false);
+ Depth newDepth = sp->depth - OnePly + ext;
// Prune?
- if(useFutilityPruning && ext == Depth(0) && !moveIsCapture
- && !moveIsPassedPawnPush && !move_promotion(move)
- && moveCount >= 2 + int(sp->depth)
- && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth))
+ if ( useFutilityPruning
+ && ext == Depth(0)
+ && !moveIsCapture
+ && !moveIsPassedPawnPush
+ && !move_promotion(move)
+ && moveCount >= 2 + int(sp->depth)
+ && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth))
continue;
// Make and search the move.
+ UndoInfo u;
pos.do_move(move, u, sp->dcCandidates);
- if(ext == Depth(0) && moveCount >= LMRNonPVMoves
- && !moveIsCapture && !move_promotion(move) && !moveIsPassedPawnPush
- && !move_is_castle(move)
- && move != ss[sp->ply].killer1 && move != ss[sp->ply].killer2) {
- ss[sp->ply].reduction = OnePly;
- value = -search(pos, ss, -(sp->beta-1), newDepth - OnePly, sp->ply+1,
- true, threadID);
+
+ // 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 ( ext == Depth(0)
+ && moveCount >= LMRNonPVMoves
+ && !moveIsCapture
+ && !moveIsPassedPawnPush
+ && !move_promotion(move)
+ && !move_is_castle(move)
+ && move != ss[sp->ply].killer1
+ && move != ss[sp->ply].killer2)
+ {
+ ss[sp->ply].reduction = OnePly;
+ value = -search(pos, ss, -(sp->beta-1), newDepth - OnePly, sp->ply+1, true, threadID);
}
else
- value = sp->beta;
- if(value >= sp->beta) {
- ss[sp->ply].reduction = Depth(0);
- value = -search(pos, ss, -(sp->beta - 1), newDepth, sp->ply+1, true,
- threadID);
+ value = sp->beta; // Just to trigger next condition
+
+ if (value >= sp->beta) // 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);
}
pos.undo_move(move, u);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
- if(thread_should_stop(threadID))
- break;
-
+ if (thread_should_stop(threadID))
+ break;
+
// New best move?
lock_grab(&(sp->lock));
- if(value > sp->bestValue && !thread_should_stop(threadID)) {
- sp->bestValue = value;
- if(sp->bestValue >= sp->beta) {
- 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;
+ if (value > sp->bestValue && !thread_should_stop(threadID))
+ {
+ sp->bestValue = value;
+ if (sp->bestValue >= sp->beta)
+ {
+ 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));
@@ -1459,10 +1551,10 @@ namespace {
// 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;
+ if (sp->master == threadID && thread_should_stop(threadID))
+ for (int i = 0; i < ActiveThreads; i++)
+ if (sp->slaves[i])
+ Threads[i].stop = true;
sp->cpus--;
sp->slaves[threadID] = 0;
@@ -1478,21 +1570,21 @@ namespace {
// don't have to repeat all this work in sp_search_pv(). 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.
-
+
void sp_search_pv(SplitPoint *sp, int threadID) {
+
assert(threadID >= 0 && threadID < ActiveThreads);
assert(ActiveThreads > 1);
-
+
Position pos = Position(sp->pos);
SearchStack *ss = sp->sstack[threadID];
Value value;
Move move;
- int moveCount = sp->moves;
- while(sp->alpha < sp->beta && !thread_should_stop(threadID)
- && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE) {
- UndoInfo u;
- Depth ext, newDepth;
+ while ( sp->alpha < sp->beta
+ && !thread_should_stop(threadID)
+ && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE)
+ {
bool moveIsCheck = pos.move_is_check(move, sp->dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
bool moveIsPassedPawnPush = pos.move_is_passed_pawn_push(move);
@@ -1503,74 +1595,88 @@ namespace {
PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move));
lock_grab(&(sp->lock));
- sp->moves++;
- moveCount = sp->moves;
+ int moveCount = ++sp->moves;
lock_release(&(sp->lock));
ss[sp->ply].currentMove = move;
-
+
// Decide the new search depth.
- ext = extension(pos, move, true, moveIsCheck, false, false);
- newDepth = sp->depth - OnePly + ext;
+ Depth ext = extension(pos, move, true, moveIsCheck, false, false);
+ Depth newDepth = sp->depth - OnePly + ext;
// Make and search the move.
+ UndoInfo u;
pos.do_move(move, u, sp->dcCandidates);
- if(ext == Depth(0) && moveCount >= LMRPVMoves && !moveIsCapture
- && !move_promotion(move) && !moveIsPassedPawnPush
- && !move_is_castle(move)
- && move != ss[sp->ply].killer1 && move != ss[sp->ply].killer2) {
- ss[sp->ply].reduction = OnePly;
- value = -search(pos, ss, -sp->alpha, newDepth - OnePly, sp->ply+1,
- true, threadID);
+
+ // 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 ( ext == Depth(0)
+ && moveCount >= LMRPVMoves
+ && !moveIsCapture
+ && !moveIsPassedPawnPush
+ && !move_promotion(move)
+ && !move_is_castle(move)
+ && move != ss[sp->ply].killer1
+ && move != ss[sp->ply].killer2)
+ {
+ ss[sp->ply].reduction = OnePly;
+ value = -search(pos, ss, -sp->alpha, newDepth - OnePly, sp->ply+1, true, threadID);
}
else
- value = sp->alpha + 1;
- if(value > sp->alpha) {
- ss[sp->ply].reduction = Depth(0);
- value = -search(pos, ss, -sp->alpha, newDepth, sp->ply+1, true,
- threadID);
- if(value > sp->alpha && value < sp->beta) {
- if(sp->ply == 1 && RootMoveNumber == 1)
- // 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.
- Threads[threadID].failHighPly1 = true;
- value = -search_pv(pos, ss, -sp->beta, -sp->alpha, newDepth,
- sp->ply+1, threadID);
- Threads[threadID].failHighPly1 = false;
+ value = sp->alpha + 1; // Just to trigger next condition
+
+ if (value > sp->alpha) // Go with full depth non-pv search
+ {
+ ss[sp->ply].reduction = Depth(0);
+ value = -search(pos, ss, -sp->alpha, newDepth, sp->ply+1, true, threadID);
+
+ if (value > sp->alpha && 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;
}
}
pos.undo_move(move, u);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
- if(thread_should_stop(threadID))
- break;
-
+ if (thread_should_stop(threadID))
+ break;
+
// New best move?
lock_grab(&(sp->lock));
- if(value > sp->bestValue && !thread_should_stop(threadID)) {
- sp->bestValue = value;
- if(value > sp->alpha) {
- 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) {
- for(int i = 0; i < ActiveThreads; i++)
- if(i != threadID && (i == sp->master || sp->slaves[i]))
- Threads[i].stop = true;
- sp->finished = true;
- }
+ if (value > sp->bestValue && !thread_should_stop(threadID))
+ {
+ sp->bestValue = value;
+ if (value > sp->alpha)
+ {
+ 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)
+ {
+ for(int i = 0; i < ActiveThreads; i++)
+ if(i != threadID && (i == sp->master || sp->slaves[i]))
+ Threads[i].stop = true;
+
+ sp->finished = true;
+ }
}
// 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(Iteration >= 2 &&
- -value <= ValueByIteration[Iteration-1] - ProblemMargin)
- Problem = true;
+ if (Iteration >= 2 && -value <= ValueByIteration[Iteration-1] - ProblemMargin)
+ Problem = true;
}
lock_release(&(sp->lock));
}
@@ -1579,16 +1685,16 @@ namespace {
// 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;
+ if (sp->master == threadID && thread_should_stop(threadID))
+ for (int i = 0; i < ActiveThreads; i++)
+ if (sp->slaves[i])
+ Threads[i].stop = true;
sp->cpus--;
sp->slaves[threadID] = 0;
lock_release(&(sp->lock));
- }
+ }
/// The RootMove class
@@ -1598,7 +1704,19 @@ namespace {
RootMove::RootMove() {
nodes = cumulativeNodes = 0ULL;
}
-
+
+ // RootMove::operator<() is the comparison function used when
+ // sorting the moves. A move m1 is considered to be better
+ // than a move m2 if it has a higher score, or if the moves
+ // have equal score but m1 has the higher node count.
+
+ bool RootMove::operator<(const RootMove& m) {
+
+ if (score != m.score)
+ return (score < m.score);
+
+ return nodes <= m.nodes;
+ }
/// The RootMoveList class
@@ -1627,7 +1745,7 @@ namespace {
SearchStack ss[PLY_MAX_PLUS_2];
moves[count].move = mlist[i].move;
- moves[count].nodes = 0ULL;
+ moves[count].nodes = 0ULL;
pos.do_move(moves[count].move, u);
moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE,
Depth(0), 1, 0);
@@ -1643,19 +1761,19 @@ namespace {
// Simple accessor methods for the RootMoveList class
- Move RootMoveList::get_move(int moveNum) const {
+ inline Move RootMoveList::get_move(int moveNum) const {
return moves[moveNum].move;
}
- Value RootMoveList::get_move_score(int moveNum) const {
+ inline Value RootMoveList::get_move_score(int moveNum) const {
return moves[moveNum].score;
}
- void RootMoveList::set_move_score(int moveNum, Value score) {
+ inline void RootMoveList::set_move_score(int moveNum, Value score) {
moves[moveNum].score = score;
}
-
- void RootMoveList::set_move_nodes(int moveNum, int64_t nodes) {
+
+ inline void RootMoveList::set_move_nodes(int moveNum, int64_t nodes) {
moves[moveNum].nodes = nodes;
moves[moveNum].cumulativeNodes += nodes;
}
@@ -1667,15 +1785,15 @@ namespace {
moves[moveNum].pv[j] = MOVE_NONE;
}
- Move RootMoveList::get_move_pv(int moveNum, int i) const {
+ inline Move RootMoveList::get_move_pv(int moveNum, int i) const {
return moves[moveNum].pv[i];
}
- int64_t RootMoveList::get_move_cumulative_nodes(int moveNum) {
+ inline int64_t RootMoveList::get_move_cumulative_nodes(int moveNum) const {
return moves[moveNum].cumulativeNodes;
}
-
- int RootMoveList::move_count() const {
+
+ inline int RootMoveList::move_count() const {
return count;
}
@@ -1690,58 +1808,44 @@ namespace {
Move RootMoveList::scan_for_easy_move() const {
- Value bestMoveValue = this->get_move_score(0);
- for(int i = 1; i < this->move_count(); i++)
- if(this->get_move_score(i) >= bestMoveValue - EasyMoveMargin)
- return MOVE_NONE;
- return this->get_move(0);
- }
+ assert(count);
+ if (count == 1)
+ return get_move(0);
+
+ // moves are sorted so just consider the best and the second one
+ if (get_move_score(0) > get_move_score(1) + EasyMoveMargin)
+ return get_move(0);
+
+ return MOVE_NONE;
+ }
// RootMoveList::sort() sorts the root move list at the beginning of a new
// iteration.
- void RootMoveList::sort() {
- for(int i = 1; i < count; i++) {
- RootMove rm = moves[i];
- int j;
- for(j = i; j > 0 && compare_root_moves(moves[j-1], rm); j--)
- moves[j] = moves[j-1];
- moves[j] = rm;
- }
+ inline void RootMoveList::sort() {
+
+ sort_multipv(count - 1); // 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
+ // list by their scores and depths. It is used to order the different PVs
// correctly in MultiPV mode.
void RootMoveList::sort_multipv(int n) {
- for(int i = 1; i <= n; i++) {
+
+ for (int i = 1; i <= n; i++)
+ {
RootMove rm = moves[i];
int j;
- for(j = i; j > 0 && moves[j-1].score < rm.score; j--)
- moves[j] = moves[j-1];
+ for (j = i; j > 0 && moves[j-1] < rm; j--)
+ moves[j] = moves[j-1];
moves[j] = rm;
}
}
- // RootMoveList::compare_root_moves() is the comparison function used by
- // RootMoveList::sort when sorting the moves. A move m1 is considered to
- // be better than a move m2 if it has a higher score, or if the moves have
- // equal score but m1 has the higher node count.
-
- bool RootMoveList::compare_root_moves(const RootMove &rm1,
- const RootMove &rm2) {
-
- if (rm1.score != rm2.score)
- return (rm1.score < rm2.score);
-
- return rm1.nodes <= rm2.nodes;
- }
-
-
// init_search_stack() initializes a search stack at the beginning of a
// new search from the root.
@@ -1794,7 +1898,7 @@ namespace {
// 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);
@@ -1885,8 +1989,8 @@ namespace {
return false;
}
-
-
+
+
// extension() decides whether a move should be searched with normal depth,
// or with extended depth. Certain classes of moves (checking moves, in
// particular) are searched with bigger depth than ordinary moves.
@@ -1972,7 +2076,7 @@ namespace {
// Case 4: Don't prune moves with good history.
if(!H.ok_to_prune(pos.piece_on(move_from(m)), m, d))
return false;
-
+
// Case 5: If the moving piece in the threatened move is a slider, don't
// prune safe moves which block its ray.
if(!PruneBlockingMoves && threat != MOVE_NONE
@@ -1982,12 +2086,52 @@ namespace {
return true;
}
-
+
+
+ // ok_to_use_TT() returns true if a transposition table score
+ // can be used at a given point in search.
+
+ bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply) {
+
+ Value v = value_from_tt(tte->value(), ply);
+
+ return ( tte->depth() >= depth
+ || v >= Max(value_mate_in(100), beta)
+ || v < Min(value_mated_in(100), beta))
+
+ && ( (is_lower_bound(tte->type()) && v >= beta)
+ || (is_upper_bound(tte->type()) && v < beta));
+ }
+
+
+ // ok_to_history() returns true if a move m can be stored
+ // in history. Should be a non capturing move.
+
+ bool ok_to_history(const Position& pos, Move m) {
+
+ return pos.square_is_empty(move_to(m))
+ && !move_promotion(m)
+ && !move_is_ep(m);
+ }
+
+
+ // update_history() registers a good move that produced a beta-cutoff
+ // in history and marks as failures all the other moves of that ply.
+
+ void update_history(const Position& pos, Move m, Depth depth,
+ Move movesSearched[], int moveCount) {
+
+ H.success(pos.piece_on(move_from(m)), m, depth);
+
+ for (int i = 0; i < moveCount - 1; i++)
+ if (ok_to_history(pos, movesSearched[i]) && m != movesSearched[i])
+ H.failure(pos.piece_on(move_from(movesSearched[i])), movesSearched[i]);
+ }
// fail_high_ply_1() checks if some thread is currently resolving a fail
// high at ply 1 at the node below the first root node. This information
// is used for time managment.
-
+
bool fail_high_ply_1() {
for(int i = 0; i < ActiveThreads; i++)
if(Threads[i].failHighPly1)
@@ -2017,62 +2161,70 @@ namespace {
// search.
void poll() {
- int t, data;
- static int lastInfoTime;
- t = current_search_time();
+ static int lastInfoTime;
+ int t = current_search_time();
// Poll for input
- data = Bioskey();
- if(data) {
- char input[256];
- if(fgets(input, 255, stdin) == NULL)
- strcpy(input, "quit\n");
- if(strncmp(input, "quit", 4) == 0) {
- AbortSearch = true;
- PonderSearch = false;
- Quit = true;
- }
- else if(strncmp(input, "stop", 4) == 0) {
- AbortSearch = true;
- PonderSearch = false;
- }
- else if(strncmp(input, "ponderhit", 9) == 0)
- ponderhit();
+ if (Bioskey())
+ {
+ // We are line oriented, don't read single chars
+ std::string command;
+ if (!std::getline(std::cin, command))
+ command = "quit";
+
+ if (command == "quit")
+ {
+ AbortSearch = true;
+ PonderSearch = false;
+ Quit = true;
+ }
+ else if(command == "stop")
+ {
+ AbortSearch = true;
+ PonderSearch = false;
+ }
+ else if(command == "ponderhit")
+ ponderhit();
}
-
// Print search information
- if(t < 1000)
- lastInfoTime = 0;
- else if(lastInfoTime > t)
- // HACK: Must be a new search where we searched less than
- // NodesBetweenPolls nodes during the first second of search.
- lastInfoTime = 0;
- else if(t - lastInfoTime >= 1000) {
- lastInfoTime = t;
- lock_grab(&IOLock);
- std::cout << "info nodes " << nodes_searched() << " nps " << nps()
- << " time " << t << " hashfull " << TT.full() << std::endl;
- lock_release(&IOLock);
- if(ShowCurrentLine)
- Threads[0].printCurrentLine = true;
- }
+ if (t < 1000)
+ lastInfoTime = 0;
+
+ else if (lastInfoTime > t)
+ // HACK: Must be a new search where we searched less than
+ // NodesBetweenPolls nodes during the first second of search.
+ lastInfoTime = 0;
+ else if (t - lastInfoTime >= 1000)
+ {
+ lastInfoTime = t;
+ lock_grab(&IOLock);
+ if (dbg_show_mean)
+ dbg_print_mean();
+
+ if (dbg_show_hit_rate)
+ dbg_print_hit_rate();
+
+ std::cout << "info nodes " << nodes_searched() << " nps " << nps()
+ << " time " << t << " hashfull " << TT.full() << std::endl;
+ lock_release(&IOLock);
+ if (ShowCurrentLine)
+ Threads[0].printCurrentLine = true;
+ }
// Should we stop the search?
- if(!PonderSearch && Iteration >= 2 &&
- (!InfiniteSearch && (t > AbsoluteMaxSearchTime ||
- (RootMoveNumber == 1 &&
- t > MaxSearchTime + ExtraSearchTime) ||
- (!FailHigh && !fail_high_ply_1() && !Problem &&
- t > 6*(MaxSearchTime + ExtraSearchTime)))))
- AbortSearch = true;
+ if (PonderSearch)
+ return;
- if(!PonderSearch && ExactMaxTime && t >= ExactMaxTime)
- AbortSearch = true;
+ bool overTime = t > AbsoluteMaxSearchTime
+ || (RootMoveNumber == 1 && t > MaxSearchTime + ExtraSearchTime)
+ || ( !FailHigh && !fail_high_ply_1() && !Problem
+ && t > 6*(MaxSearchTime + ExtraSearchTime));
- if(!PonderSearch && Iteration >= 3 && MaxNodes
- && nodes_searched() >= MaxNodes)
- AbortSearch = true;
+ if ( (Iteration >= 2 && (!InfiniteSearch && overTime))
+ || (ExactMaxTime && t >= ExactMaxTime)
+ || (Iteration >= 3 && MaxNodes && nodes_searched() >= MaxNodes))
+ AbortSearch = true;
}
@@ -2096,7 +2248,7 @@ namespace {
// 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);
@@ -2121,14 +2273,14 @@ namespace {
// "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()).
-
+
void wait_for_stop_or_ponderhit() {
std::string command;
while(true) {
if(!std::getline(std::cin, command))
command = "quit";
-
+
if(command == "quit") {
OpeningBook.close();
stop_threads();
@@ -2140,7 +2292,7 @@ namespace {
}
}
-
+
// 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.
@@ -2148,7 +2300,7 @@ namespace {
void idle_loop(int threadID, SplitPoint *waitSp) {
assert(threadID >= 0 && threadID < THREAD_MAX);
- Threads[threadID].running = true;
+ Threads[threadID].running = true;
while(true) {
if(AllThreadsShouldExit && threadID != 0)
@@ -2206,7 +2358,7 @@ namespace {
for(int i = 0; i < THREAD_MAX; i++)
for(int j = 0; j < MaxActiveSplitPoints; j++)
lock_destroy(&(SplitPointStack[i][j].lock));
- }
+ }
// thread_should_stop() checks whether the thread with a given threadID has
@@ -2216,7 +2368,7 @@ namespace {
bool thread_should_stop(int threadID) {
assert(threadID >= 0 && threadID < ActiveThreads);
-
+
SplitPoint *sp;
if(Threads[threadID].stop)
@@ -2229,7 +2381,7 @@ namespace {
return true;
}
return false;
- }
+ }
// thread_is_available() checks whether the thread with threadID "slave" is
@@ -2244,7 +2396,7 @@ namespace {
assert(slave >= 0 && slave < ActiveThreads);
assert(master >= 0 && master < ActiveThreads);
assert(ActiveThreads > 1);
-
+
if(!Threads[slave].idle || slave == master)
return false;
@@ -2263,14 +2415,14 @@ namespace {
return false;
}
-
+
// idle_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) {
assert(master >= 0 && master < ActiveThreads);
assert(ActiveThreads > 1);
-
+
for(int i = 0; i < ActiveThreads; i++)
if(thread_is_available(i, master))
return true;
@@ -2408,20 +2560,20 @@ namespace {
#endif
}
}
-
+
// 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) {
idle_loop(*(int *)threadID, NULL);
return NULL;
}
-
+
#else
DWORD WINAPI init_thread(LPVOID threadID) {