X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=86a8defd53898aa49de8ce1eefd1f9b12b64075d;hb=a1076cc68aa1fe322024d15b677499f9a03b7457;hp=74ed69ff6495b7b4a04ee84804547342192b74dd;hpb=9c7d72739cffe523f0ea8c84875160c17ae6ab82;p=stockfish
diff --git a/src/search.cpp b/src/search.cpp
index 74ed69ff..86a8defd 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1,7 +1,7 @@
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -17,6 +17,7 @@
along with this program. If not, see .
*/
+#include
#include
#include
#include
@@ -24,13 +25,11 @@
#include
#include
#include
-#include
#include "book.h"
#include "evaluate.h"
#include "history.h"
#include "misc.h"
-#include "move.h"
#include "movegen.h"
#include "movepick.h"
#include "search.h"
@@ -39,9 +38,18 @@
#include "tt.h"
#include "ucioption.h"
+namespace Search {
+
+ volatile SignalsType Signals;
+ LimitsType Limits;
+ std::vector SearchMoves;
+ Position RootPosition;
+}
+
+using std::string;
using std::cout;
using std::endl;
-using std::string;
+using namespace Search;
namespace {
@@ -52,34 +60,29 @@ namespace {
enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV };
// RootMove struct is used for moves at the root of 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). Score is normally set at
- // -VALUE_INFINITE for all non-pv moves.
+ // move we store a score, a node count, and a PV (really a refutation in the
+ // case of moves which fail low). Score is normally set at -VALUE_INFINITE for
+ // all non-pv moves.
struct RootMove {
- // 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 an higher score
+ RootMove(){}
+ RootMove(Move m) {
+ score = prevScore = -VALUE_INFINITE;
+ pv.push_back(m);
+ pv.push_back(MOVE_NONE);
+ }
+
bool operator<(const RootMove& m) const { return score < m.score; }
+ bool operator==(const Move& m) const { return pv[0] == m; }
void extract_pv_from_tt(Position& pos);
void insert_pv_in_tt(Position& pos);
- int64_t nodes;
Value score;
Value prevScore;
std::vector pv;
};
- // RootMoveList struct is mainly a std::vector of RootMove objects
- struct RootMoveList : public std::vector {
-
- void init(Position& pos, Move searchMoves[]);
- RootMove* find(const Move& m, int startIndex = 0);
-
- int bestMoveChanges;
- };
-
/// Constants
@@ -87,8 +90,6 @@ namespace {
const bool Slidings[18] = { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1 };
inline bool piece_is_slider(Piece p) { return Slidings[p]; }
- // Step 6. Razoring
-
// Maximum depth for razoring
const Depth RazorDepth = 4 * ONE_PLY;
@@ -98,8 +99,6 @@ namespace {
// Maximum depth for use of dynamic threat detection when null move fails low
const Depth ThreatDepth = 5 * ONE_PLY;
- // Step 9. Internal iterative deepening
-
// Minimum depth for use of internal iterative deepening
const Depth IIDDepth[] = { 8 * ONE_PLY, 5 * ONE_PLY };
@@ -107,19 +106,9 @@ namespace {
// when the static evaluation is bigger then beta - IIDMargin.
const Value IIDMargin = Value(0x100);
- // Step 11. Decide the new search depth
-
- // Extensions. Array index 0 is used for non-PV nodes, index 1 for PV nodes
- const Depth CheckExtension[] = { ONE_PLY / 2, ONE_PLY / 1 };
- const Depth PawnEndgameExtension[] = { ONE_PLY / 1, ONE_PLY / 1 };
- const Depth PawnPushTo7thExtension[] = { ONE_PLY / 2, ONE_PLY / 2 };
- const Depth PassedPawnExtension[] = { DEPTH_ZERO, ONE_PLY / 2 };
-
// Minimum depth for use of singular extension
const Depth SingularExtensionDepth[] = { 8 * ONE_PLY, 6 * ONE_PLY };
- // Step 12. Futility pruning
-
// Futility margin for quiescence search
const Value FutilityMarginQS = Value(0x80);
@@ -138,8 +127,6 @@ namespace {
return d < 16 * ONE_PLY ? FutilityMoveCounts[d] : MAX_MOVES;
}
- // Step 14. Reduced search
-
// Reduction lookup tables (initialized at startup) and their access function
int8_t Reductions[2][64][64]; // [pv][depth][moveNumber]
@@ -152,38 +139,30 @@ namespace {
// better than the second best move.
const Value EasyMoveMargin = Value(0x150);
+ // This is the minimum interval in msec between two check_time() calls
+ const int TimerResolution = 5;
- /// Namespace variables
-
- // Root move list
- RootMoveList Rml;
- // MultiPV mode
- int MultiPV, UCIMultiPV, MultiPVIdx;
+ /// Namespace variables
- // Time management variables
- volatile bool StopOnPonderhit, FirstRootMove, StopRequest, QuitRequest, AspirationFailLow;
+ std::vector RootMoves;
+ size_t MultiPV, UCIMultiPV, PVIdx;
TimeManager TimeMgr;
- SearchLimits Limits;
-
- // Skill level adjustment
+ int BestMoveChanges;
int SkillLevel;
- bool SkillLevelEnabled;
-
- // History table
+ bool SkillLevelEnabled, Chess960;
History H;
/// Local functions
- Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove);
-
template
- Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth);
+ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth);
template
- Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth);
+ Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth);
+ void id_loop(Position& pos);
bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bValue);
bool connected_moves(const Position& pos, Move m1, Move m2);
Value value_to_tt(Value v, int ply);
@@ -191,109 +170,61 @@ namespace {
bool can_return_tt(const TTEntry* tte, Depth depth, Value beta, int ply);
bool connected_threat(const Position& pos, Move m, Move threat);
Value refine_eval(const TTEntry* tte, Value defaultEval, int ply);
- void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
- void do_skill_level(Move* best, Move* ponder);
-
- int elapsed_search_time(int set = 0);
+ Move do_skill_level();
+ int elapsed_time(bool reset = false);
string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE);
- string speed_to_uci(int64_t nodes);
- string pv_to_uci(const Move pv[], int pvNum, bool chess960);
- string pretty_pv(Position& pos, int depth, Value score, int time, Move pv[]);
- string depth_to_uci(Depth depth);
- void wait_for_stop_or_ponderhit();
-
- // MovePickerExt template class extends MovePicker and allows to choose at compile
- // time the proper moves source according to the type of node. In the default case
- // we simply create and use a standard MovePicker object.
+ void pv_info_to_log(Position& pos, int depth, Value score, int time, Move pv[]);
+ void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta);
+
+ // MovePickerExt class template extends MovePicker and allows to choose at
+ // compile time the proper moves source according to the type of node. In the
+ // default case we simply create and use a standard MovePicker object.
template struct MovePickerExt : public MovePicker {
- MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b)
+ MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b)
: MovePicker(p, ttm, d, h, ss, b) {}
};
// In case of a SpNode we use split point's shared MovePicker object as moves source
template<> struct MovePickerExt : public MovePicker {
- MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b)
+ MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b)
: MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {}
- Move get_next_move() { return mp->get_next_move(); }
+ Move next_move() { return mp->next_move(); }
MovePicker* mp;
};
- // Overload operator<<() to make it easier to print moves in a coordinate
- // notation compatible with UCI protocol.
- std::ostream& operator<<(std::ostream& os, Move m) {
-
- bool chess960 = (os.iword(0) != 0); // See set960()
- return os << move_to_uci(m, chess960);
- }
-
- // When formatting a move for std::cout we must know if we are in Chess960
- // or not. To keep using the handy operator<<() on the move the trick is to
- // embed this flag in the stream itself. Function-like named enum set960 is
- // used as a custom manipulator and the stream internal general-purpose array,
- // accessed through ios_base::iword(), is used to pass the flag to the move's
- // operator<<() that will read it to properly format castling moves.
- enum set960 {};
-
- std::ostream& operator<< (std::ostream& os, const set960& f) {
-
- os.iword(0) = int(f);
- return os;
- }
-
- // 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 and in
- // any case are marked as 'dangerous'. Note that also if a move is not
- // extended, as example because the corresponding UCI option is set to zero,
- // the move is marked as 'dangerous' so, at least, we avoid to prune it.
- template
- FORCE_INLINE Depth extension(const Position& pos, Move m, bool captureOrPromotion,
- bool moveIsCheck, bool* dangerous) {
- assert(m != MOVE_NONE);
-
- Depth result = DEPTH_ZERO;
- *dangerous = moveIsCheck;
-
- if (moveIsCheck && pos.see_sign(m) >= 0)
- result += CheckExtension[PvNode];
+ // is_dangerous() checks whether a move belongs to some classes of known
+ // 'dangerous' moves so that we avoid to prune it.
+ FORCE_INLINE bool is_dangerous(const Position& pos, Move m, bool captureOrPromotion) {
- if (type_of(pos.piece_on(move_from(m))) == PAWN)
+ // Test for a pawn pushed to 7th or a passed pawn move
+ if (type_of(pos.piece_moved(m)) == PAWN)
{
Color c = pos.side_to_move();
- if (relative_rank(c, move_to(m)) == RANK_7)
- {
- result += PawnPushTo7thExtension[PvNode];
- *dangerous = true;
- }
- if (pos.pawn_is_passed(c, move_to(m)))
- {
- result += PassedPawnExtension[PvNode];
- *dangerous = true;
- }
+ if ( relative_rank(c, to_sq(m)) == RANK_7
+ || pos.pawn_is_passed(c, to_sq(m)))
+ return true;
}
+ // Test for a capture that triggers a pawn endgame
if ( captureOrPromotion
- && type_of(pos.piece_on(move_to(m))) != PAWN
+ && type_of(pos.piece_on(to_sq(m))) != PAWN
&& ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
- - PieceValueMidgame[pos.piece_on(move_to(m))] == VALUE_ZERO)
+ - PieceValueMidgame[pos.piece_on(to_sq(m))] == VALUE_ZERO)
&& !is_special(m))
- {
- result += PawnEndgameExtension[PvNode];
- *dangerous = true;
- }
+ return true;
- return std::min(result, ONE_PLY);
+ return false;
}
} // namespace
-/// init_search() is called during startup to initialize various lookup tables
+/// Search::init() is called during startup to initialize various lookup tables
-void init_search() {
+void Search::init() {
int d; // depth (ONE_PLY == 2)
int hd; // half depth (ONE_PLY == 1)
@@ -318,67 +249,61 @@ void init_search() {
}
-/// perft() is our utility to verify move generation. All the leaf nodes up to
-/// the given depth are generated and counted and the sum returned.
+/// Search::perft() is our utility to verify move generation. All the leaf nodes
+/// up to the given depth are generated and counted and the sum returned.
-int64_t perft(Position& pos, Depth depth) {
+int64_t Search::perft(Position& pos, Depth depth) {
StateInfo st;
- int64_t sum = 0;
+ int64_t cnt = 0;
- // Generate all legal moves
MoveList ml(pos);
- // If we are at the last ply we don't need to do and undo
- // the moves, just to count them.
- if (depth <= ONE_PLY)
+ // At the last ply just return the number of moves (leaf nodes)
+ if (depth == ONE_PLY)
return ml.size();
- // Loop through all legal moves
CheckInfo ci(pos);
for ( ; !ml.end(); ++ml)
{
pos.do_move(ml.move(), st, ci, pos.move_gives_check(ml.move(), ci));
- sum += perft(pos, depth - ONE_PLY);
+ cnt += perft(pos, depth - ONE_PLY);
pos.undo_move(ml.move());
}
- return sum;
+ return cnt;
}
-/// think() is the external interface to Stockfish's search, and is called when
-/// the program receives the UCI 'go' command. It initializes various global
-/// variables, and calls id_loop(). It returns false when a "quit" command is
-/// received during the search.
+/// Search::think() is the external interface to Stockfish's search, and is
+/// called by the main thread when the program receives the UCI 'go' command. It
+/// searches from RootPosition and at the end prints the "bestmove" to output.
-bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) {
+void Search::think() {
static Book book; // Defined static to initialize the PRNG only once
- // Save "search start" time and reset elapsed time to zero
- elapsed_search_time(get_system_time());
-
- // Initialize global search-related variables
- StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = false;
- Limits = limits;
-
- // Set output stream mode: normal or chess960. Castling notation is different
- cout << set960(pos.is_chess960());
-
- // Look for a book move
- if (Options["OwnBook"].value())
+ Position& pos = RootPosition;
+ Chess960 = pos.is_chess960();
+ elapsed_time(true);
+ TimeMgr.init(Limits, pos.startpos_ply_counter());
+ TT.new_search();
+ H.clear();
+ RootMoves.clear();
+
+ // Populate RootMoves with all the legal moves (default) or, if a SearchMoves
+ // is given, with the subset of legal moves to search.
+ for (MoveList ml(pos); !ml.end(); ++ml)
+ if (SearchMoves.empty() || count(SearchMoves.begin(), SearchMoves.end(), ml.move()))
+ RootMoves.push_back(RootMove(ml.move()));
+
+ if (Options["OwnBook"])
{
- if (Options["Book File"].value() != book.name())
- book.open(Options["Book File"].value());
+ Move bookMove = book.probe(pos, Options["Book File"], Options["Best Book Move"]);
- Move bookMove = book.probe(pos, Options["Best Book Move"].value());
- if (bookMove != MOVE_NONE)
+ if (bookMove && count(RootMoves.begin(), RootMoves.end(), bookMove))
{
- if (Limits.ponder)
- wait_for_stop_or_ponderhit();
-
- cout << "bestmove " << bookMove << endl;
- return !QuitRequest;
+ std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), bookMove));
+ goto finalize;
}
}
@@ -386,27 +311,24 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) {
read_evaluation_uci_options(pos.side_to_move());
Threads.read_uci_options();
- // Set a new TT size if changed
- TT.set_size(Options["Hash"].value());
-
- if (Options["Clear Hash"].value())
+ TT.set_size(Options["Hash"]);
+ if (Options["Clear Hash"])
{
- Options["Clear Hash"].set_value("false");
+ Options["Clear Hash"] = false;
TT.clear();
}
- UCIMultiPV = Options["MultiPV"].value();
- SkillLevel = Options["Skill Level"].value();
+ UCIMultiPV = Options["MultiPV"];
+ SkillLevel = Options["Skill Level"];
// Do we have to play with skill handicap? In this case enable MultiPV that
// we will use behind the scenes to retrieve a set of possible moves.
SkillLevelEnabled = (SkillLevel < 20);
- MultiPV = (SkillLevelEnabled ? std::max(UCIMultiPV, 4) : UCIMultiPV);
+ MultiPV = (SkillLevelEnabled ? std::max(UCIMultiPV, (size_t)4) : UCIMultiPV);
- // Write current search header to log file
- if (Options["Use Search Log"].value())
+ if (Options["Use Search Log"])
{
- Log log(Options["Search Log Filename"].value());
+ Log log(Options["Search Log Filename"]);
log << "\nSearching: " << pos.to_fen()
<< "\ninfinite: " << Limits.infinite
<< " ponder: " << Limits.ponder
@@ -416,7 +338,6 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) {
<< endl;
}
- // Wake up needed threads and reset maxPly counter
for (int i = 0; i < Threads.size(); i++)
{
Threads[i].maxPly = 0;
@@ -425,63 +346,44 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) {
// Set best timer interval to avoid lagging under time pressure. Timer is
// used to check for remaining available thinking time.
- TimeMgr.init(Limits, pos.startpos_ply_counter());
-
- if (TimeMgr.available_time())
- Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 8, 20)));
+ if (Limits.use_time_management())
+ Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution)));
else
Threads.set_timer(100);
- // Start async mode to catch UCI commands sent to us while searching,
- // like "quit", "stop", etc.
- Threads.start_listener();
-
- // We're ready to start thinking. Call the iterative deepening loop function
- Move ponderMove = MOVE_NONE;
- Move bestMove = id_loop(pos, searchMoves, &ponderMove);
-
- // From now on any UCI command will be read in-sync with Threads.getline()
- Threads.stop_listener();
+ // We're ready to start searching. Call the iterative deepening loop function
+ id_loop(pos);
- // Stop timer, no need to check for available time any more
+ // Stop timer and send all the slaves to sleep, if not already sleeping
Threads.set_timer(0);
-
- // This makes all the slave threads to go to sleep, if not already sleeping
Threads.set_size(1);
- // Write current search final statistics to log file
- if (Options["Use Search Log"].value())
+ if (Options["Use Search Log"])
{
- int e = elapsed_search_time();
+ int e = elapsed_time();
- Log log(Options["Search Log Filename"].value());
+ Log log(Options["Search Log Filename"]);
log << "Nodes: " << pos.nodes_searched()
<< "\nNodes/second: " << (e > 0 ? pos.nodes_searched() * 1000 / e : 0)
- << "\nBest move: " << move_to_san(pos, bestMove);
+ << "\nBest move: " << move_to_san(pos, RootMoves[0].pv[0]);
StateInfo st;
- pos.do_move(bestMove, st);
- log << "\nPonder move: " << move_to_san(pos, ponderMove) << endl;
- pos.undo_move(bestMove); // Return from think() with unchanged position
+ pos.do_move(RootMoves[0].pv[0], st);
+ log << "\nPonder move: " << move_to_san(pos, RootMoves[0].pv[1]) << endl;
+ pos.undo_move(RootMoves[0].pv[0]);
}
+finalize:
+
// When we reach max depth we arrive here even without a StopRequest, but if
// we are pondering or in infinite search, we shouldn't print the best move
// before we are told to do so.
- if (!StopRequest && (Limits.ponder || Limits.infinite))
- wait_for_stop_or_ponderhit();
-
- // Could be MOVE_NONE when searching on a stalemate position
- cout << "bestmove " << bestMove;
+ if (!Signals.stop && (Limits.ponder || Limits.infinite))
+ Threads.wait_for_stop_or_ponderhit();
- // UCI protol is not clear on allowing sending an empty ponder move, instead
- // it is clear that ponder move is optional. So skip it if empty.
- if (ponderMove != MOVE_NONE)
- cout << " ponder " << ponderMove;
-
- cout << endl;
-
- return !QuitRequest;
+ // Best move could be MOVE_NONE when searching on a stalemate position
+ cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960)
+ << " ponder " << move_to_uci(RootMoves[0].pv[1], Chess960) << endl;
}
@@ -491,60 +393,49 @@ namespace {
// with increasing depth until the allocated thinking time has been consumed,
// user stops the search, or the maximum search depth is reached.
- Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove) {
+ void id_loop(Position& pos) {
- SearchStack ss[PLY_MAX_PLUS_2];
- Value bestValues[PLY_MAX_PLUS_2];
- int bestMoveChanges[PLY_MAX_PLUS_2];
- int depth, aspirationDelta;
- Value bestValue, alpha, beta;
- Move bestMove, skillBest, skillPonder;
+ Stack ss[MAX_PLY_PLUS_2];
+ int depth, prevBestMoveChanges;
+ Value bestValue, alpha, beta, delta;
bool bestMoveNeverChanged = true;
+ Move skillBest = MOVE_NONE;
- // Initialize stuff before a new search
- memset(ss, 0, 4 * sizeof(SearchStack));
- TT.new_search();
- H.clear();
- *ponderMove = bestMove = skillBest = skillPonder = MOVE_NONE;
- depth = aspirationDelta = 0;
- bestValue = alpha = -VALUE_INFINITE, beta = VALUE_INFINITE;
+ memset(ss, 0, 4 * sizeof(Stack));
+ depth = BestMoveChanges = 0;
+ bestValue = delta = -VALUE_INFINITE;
ss->currentMove = MOVE_NULL; // Hack to skip update gains
- // Moves to search are verified and copied
- Rml.init(pos, searchMoves);
-
- // Handle special case of searching on a mate/stalemate position
- if (!Rml.size())
+ // Handle the special case of a mated/stalemate position
+ if (RootMoves.empty())
{
- cout << "info" << depth_to_uci(DEPTH_ZERO)
- << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW, alpha, beta) << endl;
+ cout << "info depth 0 score "
+ << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl;
- return MOVE_NONE;
+ RootMoves.push_back(MOVE_NONE);
+ return;
}
// Iterative deepening loop until requested to stop or target depth reached
- while (!StopRequest && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth))
+ while (!Signals.stop && ++depth <= MAX_PLY && (!Limits.maxDepth || depth <= Limits.maxDepth))
{
- // Save now last iteration's scores, before Rml moves are reordered
- for (size_t i = 0; i < Rml.size(); i++)
- Rml[i].prevScore = Rml[i].score;
+ // Save last iteration's scores before first PV line is searched and all
+ // the move scores but the (new) PV are set to -VALUE_INFINITE.
+ for (size_t i = 0; i < RootMoves.size(); i++)
+ RootMoves[i].prevScore = RootMoves[i].score;
- Rml.bestMoveChanges = 0;
+ prevBestMoveChanges = BestMoveChanges;
+ BestMoveChanges = 0;
// MultiPV loop. We perform a full root search for each PV line
- for (MultiPVIdx = 0; MultiPVIdx < std::min(MultiPV, (int)Rml.size()); MultiPVIdx++)
+ for (PVIdx = 0; PVIdx < std::min(MultiPV, RootMoves.size()); PVIdx++)
{
- // Calculate dynamic aspiration window based on previous iterations
- if (depth >= 5 && abs(Rml[MultiPVIdx].prevScore) < VALUE_KNOWN_WIN)
+ // Set aspiration window default width
+ if (depth >= 5 && abs(RootMoves[PVIdx].prevScore) < VALUE_KNOWN_WIN)
{
- int prevDelta1 = bestValues[depth - 1] - bestValues[depth - 2];
- int prevDelta2 = bestValues[depth - 2] - bestValues[depth - 3];
-
- aspirationDelta = std::min(std::max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24);
- aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize
-
- alpha = std::max(Rml[MultiPVIdx].prevScore - aspirationDelta, -VALUE_INFINITE);
- beta = std::min(Rml[MultiPVIdx].prevScore + aspirationDelta, VALUE_INFINITE);
+ delta = Value(16);
+ alpha = RootMoves[PVIdx].prevScore - delta;
+ beta = RootMoves[PVIdx].prevScore + delta;
}
else
{
@@ -565,139 +456,117 @@ namespace {
// we want to keep the same order for all the moves but the new
// PV that goes to the front. Note that in case of MultiPV search
// the already searched PV lines are preserved.
- sort(Rml.begin() + MultiPVIdx, Rml.end());
+ sort(RootMoves.begin() + PVIdx, RootMoves.end());
// In case we have found an exact score and we are going to leave
// the fail high/low loop then reorder the PV moves, otherwise
// leave the last PV move in its position so to be searched again.
// Of course this is needed only in MultiPV search.
- if (MultiPVIdx && bestValue > alpha && bestValue < beta)
- sort(Rml.begin(), Rml.begin() + MultiPVIdx);
-
- // Write PV back to transposition table in case the relevant entries
- // have been overwritten during the search.
- for (int i = 0; i <= MultiPVIdx; i++)
- Rml[i].insert_pv_in_tt(pos);
-
- // If search has been stopped exit the aspiration window loop,
- // note that sorting and writing PV back to TT is safe becuase
- // Rml is still valid, although refers to the previous iteration.
- if (StopRequest)
+ if (PVIdx && bestValue > alpha && bestValue < beta)
+ sort(RootMoves.begin(), RootMoves.begin() + PVIdx);
+
+ // Write PV back to transposition table in case the relevant
+ // entries have been overwritten during the search.
+ for (size_t i = 0; i <= PVIdx; i++)
+ RootMoves[i].insert_pv_in_tt(pos);
+
+ // If search has been stopped exit the aspiration window loop.
+ // Sorting and writing PV back to TT is safe becuase RootMoves
+ // is still valid, although refers to previous iteration.
+ if (Signals.stop)
break;
// Send full PV info to GUI if we are going to leave the loop or
- // if we have a fail high/low and we are deep in the search. UCI
- // protocol requires to send all the PV lines also if are still
- // to be searched and so refer to the previous search's score.
- if ((bestValue > alpha && bestValue < beta) || elapsed_search_time() > 2000)
- for (int i = 0; i < std::min(UCIMultiPV, (int)Rml.size()); i++)
- {
- bool updated = (i <= MultiPVIdx);
-
- if (depth == 1 && !updated)
- continue;
-
- Depth d = (updated ? depth : depth - 1) * ONE_PLY;
- Value s = (updated ? Rml[i].score : Rml[i].prevScore);
-
- cout << "info"
- << depth_to_uci(d)
- << (i == MultiPVIdx ? score_to_uci(s, alpha, beta) : score_to_uci(s))
- << speed_to_uci(pos.nodes_searched())
- << pv_to_uci(&Rml[i].pv[0], i + 1, pos.is_chess960())
- << endl;
- }
+ // if we have a fail high/low and we are deep in the search.
+ if ((bestValue > alpha && bestValue < beta) || elapsed_time() > 2000)
+ pv_info_to_uci(pos, depth, alpha, beta);
// In case of failing high/low increase aspiration window and
// research, otherwise exit the fail high/low loop.
if (bestValue >= beta)
{
- beta = std::min(beta + aspirationDelta, VALUE_INFINITE);
- aspirationDelta += aspirationDelta / 2;
+ beta += delta;
+ delta += delta / 2;
}
else if (bestValue <= alpha)
{
- AspirationFailLow = true;
- StopOnPonderhit = false;
+ Signals.failedLowAtRoot = true;
+ Signals.stopOnPonderhit = false;
- alpha = std::max(alpha - aspirationDelta, -VALUE_INFINITE);
- aspirationDelta += aspirationDelta / 2;
+ alpha -= delta;
+ delta += delta / 2;
}
else
break;
+ assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
+
} while (abs(bestValue) < VALUE_KNOWN_WIN);
}
- // Collect info about search result
- bestMove = Rml[0].pv[0];
- *ponderMove = Rml[0].pv[1];
- bestValues[depth] = bestValue;
- bestMoveChanges[depth] = Rml.bestMoveChanges;
-
- // Skills: Do we need to pick now the best and the ponder moves ?
+ // Skills: Do we need to pick now the best move ?
if (SkillLevelEnabled && depth == 1 + SkillLevel)
- do_skill_level(&skillBest, &skillPonder);
+ skillBest = do_skill_level();
- if (Options["Use Search Log"].value())
- {
- Log log(Options["Search Log Filename"].value());
- log << pretty_pv(pos, depth, bestValue, elapsed_search_time(), &Rml[0].pv[0]) << endl;
- }
+ if (Options["Use Search Log"])
+ pv_info_to_log(pos, depth, bestValue, elapsed_time(), &RootMoves[0].pv[0]);
// Filter out startup noise when monitoring best move stability
- if (depth > 2 && bestMoveChanges[depth])
+ if (depth > 2 && BestMoveChanges)
bestMoveNeverChanged = false;
// Do we have time for the next iteration? Can we stop searching now?
- if (!StopRequest && !StopOnPonderhit && Limits.useTimeManagement())
+ if (!Signals.stop && !Signals.stopOnPonderhit && Limits.use_time_management())
{
+ bool stop = false; // Local variable, not the volatile Signals.stop
+
// Take in account some extra time if the best move has changed
if (depth > 4 && depth < 50)
- TimeMgr.pv_instability(bestMoveChanges[depth], bestMoveChanges[depth - 1]);
+ TimeMgr.pv_instability(BestMoveChanges, prevBestMoveChanges);
- // Stop search if most of available time is already consumed. We probably don't
- // have enough time to search the first move at the next iteration anyway.
- if (elapsed_search_time() > (TimeMgr.available_time() * 62) / 100)
- StopRequest = true;
+ // Stop search if most of available time is already consumed. We
+ // probably don't have enough time to search the first move at the
+ // next iteration anyway.
+ if (elapsed_time() > (TimeMgr.available_time() * 62) / 100)
+ stop = true;
// Stop search early if one move seems to be much better than others
- if ( depth >= 10
- && !StopRequest
- && ( bestMoveNeverChanged
- || elapsed_search_time() > (TimeMgr.available_time() * 40) / 100))
+ if ( depth >= 12
+ && !stop
+ && ( (bestMoveNeverChanged && pos.captured_piece_type())
+ || elapsed_time() > (TimeMgr.available_time() * 40) / 100))
{
Value rBeta = bestValue - EasyMoveMargin;
- (ss+1)->excludedMove = bestMove;
+ (ss+1)->excludedMove = RootMoves[0].pv[0];
(ss+1)->skipNullMove = true;
- Value v = search(pos, ss+1, rBeta - 1, rBeta, (depth * ONE_PLY) / 2);
+ Value v = search(pos, ss+1, rBeta - 1, rBeta, (depth - 3) * ONE_PLY);
(ss+1)->skipNullMove = false;
(ss+1)->excludedMove = MOVE_NONE;
if (v < rBeta)
- StopRequest = true;
+ stop = true;
}
- // If we are allowed to ponder do not stop the search now but keep pondering
- if (StopRequest && Limits.ponder) // FIXME Limits.ponder is racy
+ if (stop)
{
- StopRequest = false;
- StopOnPonderhit = true;
+ // If we are allowed to ponder do not stop the search now but
+ // keep pondering until GUI sends "ponderhit" or "stop".
+ if (Limits.ponder)
+ Signals.stopOnPonderhit = true;
+ else
+ Signals.stop = true;
}
}
}
- // When using skills overwrite best and ponder moves with the sub-optimal ones
+ // When using skills swap best PV line with the sub-optimal one
if (SkillLevelEnabled)
{
if (skillBest == MOVE_NONE) // Still unassigned ?
- do_skill_level(&skillBest, &skillPonder);
+ skillBest = do_skill_level();
- bestMove = skillBest;
- *ponderMove = skillPonder;
+ std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), skillBest));
}
-
- return bestMove;
}
@@ -709,19 +578,18 @@ namespace {
// here: This is taken care of after we return from the split point.
template
- Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) {
+ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV || NT == SplitPointRoot);
const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot);
const bool RootNode = (NT == Root || NT == SplitPointRoot);
- assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
- assert(beta > alpha && beta <= VALUE_INFINITE);
- assert(PvNode || alpha == beta - 1);
+ assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
+ assert(PvNode == (alpha != beta - 1));
+ assert(depth > DEPTH_ZERO);
assert(pos.thread() >= 0 && pos.thread() < Threads.size());
Move movesSearched[MAX_MOVES];
- int64_t nodes;
StateInfo st;
const TTEntry *tte;
Key posKey;
@@ -730,7 +598,8 @@ namespace {
ValueType vt;
Value bestValue, value, oldAlpha;
Value refinedValue, nullValue, futilityBase, futilityValue;
- bool isPvMove, inCheck, singularExtensionNode, givesCheck, captureOrPromotion, dangerous;
+ bool isPvMove, inCheck, singularExtensionNode, givesCheck;
+ bool captureOrPromotion, dangerous, doFullDepthSearch;
int moveCount = 0, playedMoveCount = 0;
Thread& thread = Threads[pos.thread()];
SplitPoint* sp = NULL;
@@ -761,16 +630,21 @@ namespace {
}
// Step 2. Check for aborted search and immediate draw
- if (( StopRequest
+ if (( Signals.stop
|| pos.is_draw()
- || ss->ply > PLY_MAX) && !RootNode)
+ || ss->ply > MAX_PLY) && !RootNode)
return VALUE_DRAW;
- // Step 3. Mate distance pruning
+ // Step 3. Mate distance pruning. Even if we mate at the next move our score
+ // would be at best mate_in(ss->ply+1), but if alpha is already bigger because
+ // a shorter mate was found upward in the tree then there is no need to search
+ // further, we will never beat current alpha. Same logic but with reversed signs
+ // applies also in the opposite condition of being mated instead of giving mate,
+ // in this case return a fail-high score.
if (!RootNode)
{
- alpha = std::max(value_mated_in(ss->ply), alpha);
- beta = std::min(value_mate_in(ss->ply+1), beta);
+ alpha = std::max(mated_in(ss->ply), alpha);
+ beta = std::min(mate_in(ss->ply+1), beta);
if (alpha >= beta)
return alpha;
}
@@ -779,9 +653,9 @@ namespace {
// We don't want the score of a partial search to overwrite a previous full search
// TT value, so we use a different position key in case of an excluded move.
excludedMove = ss->excludedMove;
- posKey = excludedMove ? pos.get_exclusion_key() : pos.get_key();
+ posKey = excludedMove ? pos.exclusion_key() : pos.key();
tte = TT.probe(posKey);
- ttMove = RootNode ? Rml[MultiPVIdx].pv[0] : tte ? tte->move() : MOVE_NONE;
+ ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE;
// At PV nodes we check for exact scores, while at non-PV nodes we check for
// a fail high/low. Biggest advantage at probing at PV nodes is to have a
@@ -827,10 +701,10 @@ namespace {
if ( (move = (ss-1)->currentMove) != MOVE_NULL
&& (ss-1)->eval != VALUE_NONE
&& ss->eval != VALUE_NONE
- && pos.captured_piece_type() == PIECE_TYPE_NONE
+ && !pos.captured_piece_type()
&& !is_special(move))
{
- Square to = move_to(move);
+ Square to = to_sq(move);
H.update_gain(pos.piece_on(to), to, -(ss-1)->eval - ss->eval);
}
@@ -840,7 +714,7 @@ namespace {
&& !inCheck
&& refinedValue + razor_margin(depth) < beta
&& ttMove == MOVE_NONE
- && abs(beta) < VALUE_MATE_IN_PLY_MAX
+ && abs(beta) < VALUE_MATE_IN_MAX_PLY
&& !pos.has_pawn_on_7th(pos.side_to_move()))
{
Value rbeta = beta - razor_margin(depth);
@@ -859,7 +733,7 @@ namespace {
&& depth < RazorDepth
&& !inCheck
&& refinedValue - futility_margin(depth, 0) >= beta
- && abs(beta) < VALUE_MATE_IN_PLY_MAX
+ && abs(beta) < VALUE_MATE_IN_MAX_PLY
&& pos.non_pawn_material(pos.side_to_move()))
return refinedValue - futility_margin(depth, 0);
@@ -869,7 +743,7 @@ namespace {
&& depth > ONE_PLY
&& !inCheck
&& refinedValue >= beta
- && abs(beta) < VALUE_MATE_IN_PLY_MAX
+ && abs(beta) < VALUE_MATE_IN_MAX_PLY
&& pos.non_pawn_material(pos.side_to_move()))
{
ss->currentMove = MOVE_NULL;
@@ -891,7 +765,7 @@ namespace {
if (nullValue >= beta)
{
// Do not return unproven mate scores
- if (nullValue >= VALUE_MATE_IN_PLY_MAX)
+ if (nullValue >= VALUE_MATE_IN_MAX_PLY)
nullValue = beta;
if (depth < 6 * ONE_PLY)
@@ -932,7 +806,7 @@ namespace {
&& !inCheck
&& !ss->skipNullMove
&& excludedMove == MOVE_NONE
- && abs(beta) < VALUE_MATE_IN_PLY_MAX)
+ && abs(beta) < VALUE_MATE_IN_MAX_PLY)
{
Value rbeta = beta + 200;
Depth rdepth = depth - ONE_PLY - 3 * ONE_PLY;
@@ -942,7 +816,7 @@ namespace {
MovePicker mp(pos, ttMove, H, pos.captured_piece_type());
CheckInfo ci(pos);
- while ((move = mp.get_next_move()) != MOVE_NONE)
+ while ((move = mp.next_move()) != MOVE_NONE)
if (pos.pl_move_is_legal(move, ci.pinned))
{
pos.do_move(move, st, ci, pos.move_gives_check(move, ci));
@@ -970,7 +844,6 @@ namespace {
split_point_start: // At split points actual search starts from here
- // Initialize a MovePicker object for the current position
MovePickerExt mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta);
CheckInfo ci(pos);
ss->bestMove = MOVE_NONE;
@@ -979,20 +852,24 @@ split_point_start: // At split points actual search starts from here
&& !SpNode
&& depth >= SingularExtensionDepth[PvNode]
&& ttMove != MOVE_NONE
- && !excludedMove // Do not allow recursive singular extension search
+ && !excludedMove // Recursive singular search is not allowed
&& (tte->type() & VALUE_TYPE_LOWER)
&& tte->depth() >= depth - 3 * ONE_PLY;
if (SpNode)
{
lock_grab(&(sp->lock));
bestValue = sp->bestValue;
+ moveCount = sp->moveCount;
+
+ assert(bestValue > -VALUE_INFINITE && moveCount > 0);
}
// Step 11. Loop through moves
// Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
- && (move = mp.get_next_move()) != MOVE_NONE
- && !thread.cutoff_occurred())
+ && (move = mp.next_move()) != MOVE_NONE
+ && !thread.cutoff_occurred()
+ && !Signals.stop)
{
assert(is_ok(move));
@@ -1002,7 +879,7 @@ split_point_start: // At split points actual search starts from here
// At root obey the "searchmoves" option and skip moves not listed in Root
// Move List, as a consequence any illegal move is also skipped. In MultiPV
// mode we also skip PV moves which have been already searched.
- if (RootNode && !Rml.find(move, MultiPVIdx))
+ if (RootNode && !count(RootMoves.begin() + PVIdx, RootMoves.end(), move))
continue;
// At PV and SpNode nodes we want all moves to be legal since the beginning
@@ -1019,25 +896,26 @@ split_point_start: // At split points actual search starts from here
if (RootNode)
{
- // This is used by time management
- FirstRootMove = (moveCount == 1);
-
- // Save the current node count before the move is searched
- nodes = pos.nodes_searched();
+ Signals.firstRootMove = (moveCount == 1);
- // For long searches send current move info to GUI
- if (pos.thread() == 0 && elapsed_search_time() > 2000)
- cout << "info" << depth_to_uci(depth)
- << " currmove " << move
- << " currmovenumber " << moveCount + MultiPVIdx << endl;
+ if (pos.thread() == 0 && elapsed_time() > 2000)
+ cout << "info depth " << depth / ONE_PLY
+ << " currmove " << move_to_uci(move, Chess960)
+ << " currmovenumber " << moveCount + PVIdx << endl;
}
isPvMove = (PvNode && moveCount <= 1);
- givesCheck = pos.move_gives_check(move, ci);
captureOrPromotion = pos.is_capture_or_promotion(move);
+ givesCheck = pos.move_gives_check(move, ci);
+ dangerous = givesCheck || is_dangerous(pos, move, captureOrPromotion);
+ ext = DEPTH_ZERO;
+
+ // Step 12. Extend checks and, in PV nodes, also dangerous moves
+ if (PvNode && dangerous)
+ ext = ONE_PLY;
- // Step 12. Decide the new search depth
- ext = extension(pos, move, captureOrPromotion, givesCheck, &dangerous);
+ else if (givesCheck && pos.see_sign(move) >= 0)
+ ext = PvNode ? ONE_PLY : ONE_PLY / 2;
// Singular extension search. If all moves but one fail low on a search of
// (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
@@ -1045,9 +923,9 @@ split_point_start: // At split points actual search starts from here
// on all the other moves but the ttMove, if result is lower than ttValue minus
// a margin then we extend ttMove.
if ( singularExtensionNode
+ && !ext
&& move == ttMove
- && pos.pl_move_is_legal(move, ci.pinned)
- && ext < ONE_PLY)
+ && pos.pl_move_is_legal(move, ci.pinned))
{
Value ttValue = value_from_tt(tte->value(), ss->ply);
@@ -1056,11 +934,11 @@ split_point_start: // At split points actual search starts from here
Value rBeta = ttValue - int(depth);
ss->excludedMove = move;
ss->skipNullMove = true;
- Value v = search(pos, ss, rBeta - 1, rBeta, depth / 2);
+ value = search(pos, ss, rBeta - 1, rBeta, depth / 2);
ss->skipNullMove = false;
ss->excludedMove = MOVE_NONE;
ss->bestMove = MOVE_NONE;
- if (v < rBeta)
+ if (value < rBeta)
ext = ONE_PLY;
}
}
@@ -1074,12 +952,12 @@ split_point_start: // At split points actual search starts from here
&& !inCheck
&& !dangerous
&& move != ttMove
- && !is_castle(move))
+ && !is_castle(move)
+ && (bestValue > VALUE_MATED_IN_MAX_PLY || bestValue == -VALUE_INFINITE))
{
// Move count based pruning
if ( moveCount >= futility_move_count(depth)
- && (!threatMove || !connected_threat(pos, move, threatMove))
- && bestValue > VALUE_MATED_IN_PLY_MAX) // FIXME bestValue is racy
+ && (!threatMove || !connected_threat(pos, move, threatMove)))
{
if (SpNode)
lock_grab(&(sp->lock));
@@ -1092,25 +970,18 @@ split_point_start: // At split points actual search starts from here
// but fixing this made program slightly weaker.
Depth predictedDepth = newDepth - reduction(depth, moveCount);
futilityValue = futilityBase + futility_margin(predictedDepth, moveCount)
- + H.gain(pos.piece_on(move_from(move)), move_to(move));
+ + H.gain(pos.piece_moved(move), to_sq(move));
if (futilityValue < beta)
{
if (SpNode)
- {
lock_grab(&(sp->lock));
- if (futilityValue > sp->bestValue)
- sp->bestValue = bestValue = futilityValue;
- }
- else if (futilityValue > bestValue)
- bestValue = futilityValue;
continue;
}
// Prune moves with negative SEE at low depths
if ( predictedDepth < 2 * ONE_PLY
- && bestValue > VALUE_MATED_IN_PLY_MAX
&& pos.see_sign(move) < 0)
{
if (SpNode)
@@ -1134,51 +1005,44 @@ split_point_start: // At split points actual search starts from here
// Step 14. Make the move
pos.do_move(move, st, ci, givesCheck);
- // Step extra. pv search (only in PV nodes)
- // The first move in list is the expected PV
- if (isPvMove)
- value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
- : - search(pos, ss+1, -beta, -alpha, newDepth);
- else
+ // Step 15. Reduced depth search (LMR). If the move fails high will be
+ // re-searched at full depth.
+ if ( depth > 3 * ONE_PLY
+ && !isPvMove
+ && !captureOrPromotion
+ && !dangerous
+ && !is_castle(move)
+ && ss->killers[0] != move
+ && ss->killers[1] != move)
{
- // Step 15. Reduced depth search
- // If the move fails high will be re-searched at full depth.
- bool doFullDepthSearch = true;
-
- if ( depth > 3 * ONE_PLY
- && !captureOrPromotion
- && !dangerous
- && !is_castle(move)
- && ss->killers[0] != move
- && ss->killers[1] != move
- && (ss->reduction = reduction(depth, moveCount)) != DEPTH_ZERO)
- {
- Depth d = newDepth - ss->reduction;
- alpha = SpNode ? sp->alpha : alpha;
+ ss->reduction = reduction(depth, moveCount);
+ Depth d = newDepth - ss->reduction;
+ alpha = SpNode ? sp->alpha : alpha;
- value = d < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
- : - search(pos, ss+1, -(alpha+1), -alpha, d);
+ value = d < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
+ : - search(pos, ss+1, -(alpha+1), -alpha, d);
- ss->reduction = DEPTH_ZERO;
- doFullDepthSearch = (value > alpha);
- }
+ doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO);
+ ss->reduction = DEPTH_ZERO;
+ }
+ else
+ doFullDepthSearch = !isPvMove;
- // Step 16. Full depth search
- if (doFullDepthSearch)
- {
- alpha = SpNode ? sp->alpha : alpha;
- value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
- : - search(pos, ss+1, -(alpha+1), -alpha, newDepth);
-
- // Step extra. pv search (only in PV nodes)
- // Search only for possible new PV nodes, if instead value >= beta then
- // parent node fails low with value <= alpha and tries another move.
- if (PvNode && value > alpha && (RootNode || value < beta))
- value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
- : - search(pos, ss+1, -beta, -alpha, newDepth);
- }
+ // Step 16. Full depth search, when LMR is skipped or fails high
+ if (doFullDepthSearch)
+ {
+ alpha = SpNode ? sp->alpha : alpha;
+ value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
+ : - search(pos, ss+1, -(alpha+1), -alpha, newDepth);
}
+ // Only for PV nodes do a full PV search on the first move or after a fail
+ // high, in the latter case search only if value < beta, otherwise let the
+ // parent node to fail low with value <= alpha and to try another move.
+ if (PvNode && (isPvMove || (value > alpha && (RootNode || value < beta))))
+ value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
+ : - search(pos, ss+1, -beta, -alpha, newDepth);
+
// Step 17. Undo move
pos.undo_move(move);
@@ -1196,32 +1060,29 @@ split_point_start: // At split points actual search starts from here
// 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 don't update the best move and/or PV.
- if (RootNode && !StopRequest)
+ if (RootNode && !Signals.stop)
{
- // Remember searched nodes counts for this move
- RootMove* rm = Rml.find(move);
- rm->nodes += pos.nodes_searched() - nodes;
+ RootMove& rm = *find(RootMoves.begin(), RootMoves.end(), move);
// PV move or new best move ?
if (isPvMove || value > alpha)
{
- // Update PV
- rm->score = value;
- rm->extract_pv_from_tt(pos);
+ rm.score = value;
+ rm.extract_pv_from_tt(pos);
// We record how often the best move has been changed in each
// iteration. This information is used for time management: When
// the best move changes frequently, we allocate some more time.
if (!isPvMove && MultiPV == 1)
- Rml.bestMoveChanges++;
+ BestMoveChanges++;
}
else
// All other moves but the PV are set to the lowest value, this
// is not a problem when sorting becuase sort is stable and move
// position in the list is preserved, just the PV is pushed up.
- rm->score = -VALUE_INFINITE;
+ rm.score = -VALUE_INFINITE;
- } // RootNode
+ }
if (value > bestValue)
{
@@ -1247,7 +1108,7 @@ split_point_start: // At split points actual search starts from here
&& depth >= Threads.min_split_depth()
&& bestValue < beta
&& Threads.available_slave_exists(pos.thread())
- && !StopRequest
+ && !Signals.stop
&& !thread.cutoff_occurred())
bestValue = Threads.split(pos, ss, alpha, beta, bestValue, depth,
threatMove, moveCount, &mp, NT);
@@ -1259,13 +1120,20 @@ split_point_start: // At split points actual search starts from here
// case of StopRequest or thread.cutoff_occurred() are set, but this is
// harmless because return value is discarded anyhow in the parent nodes.
// If we are in a singular extension search then return a fail low score.
- if (!SpNode && !moveCount)
- return excludedMove ? oldAlpha : inCheck ? value_mated_in(ss->ply) : VALUE_DRAW;
+ if (!moveCount)
+ return excludedMove ? oldAlpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW;
+
+ // If we have pruned all the moves without searching return a fail-low score
+ if (bestValue == -VALUE_INFINITE)
+ {
+ assert(!playedMoveCount);
+
+ bestValue = alpha;
+ }
// Step 21. Update tables
- // If the search is not aborted, update the transposition table,
- // history counters, and killer moves.
- if (!SpNode && !StopRequest && !thread.cutoff_occurred())
+ // Update transposition table entry, killers and history
+ if (!SpNode && !Signals.stop && !thread.cutoff_occurred())
{
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER
@@ -1273,16 +1141,27 @@ split_point_start: // At split points actual search starts from here
TT.store(posKey, value_to_tt(bestValue, ss->ply), vt, depth, move, ss->eval, ss->evalMargin);
- // Update killers and history only for non capture moves that fails high
+ // Update killers and history for non capture cut-off moves
if ( bestValue >= beta
- && !pos.is_capture_or_promotion(move))
+ && !pos.is_capture_or_promotion(move)
+ && !inCheck)
{
if (move != ss->killers[0])
{
ss->killers[1] = ss->killers[0];
ss->killers[0] = move;
}
- update_history(pos, move, depth, movesSearched, playedMoveCount);
+
+ // Increase history value of the cut-off move
+ Value bonus = Value(int(depth) * int(depth));
+ H.add(pos.piece_moved(move), to_sq(move), bonus);
+
+ // Decrease history of all the other played non-capture moves
+ for (int i = 0; i < playedMoveCount - 1; i++)
+ {
+ Move m = movesSearched[i];
+ H.add(pos.piece_moved(m), to_sq(m), -bonus);
+ }
}
}
@@ -1299,20 +1178,20 @@ split_point_start: // At split points actual search starts from here
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,
// less than ONE_PLY).
template
- Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) {
+ Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
const bool PvNode = (NT == PV);
assert(NT == PV || NT == NonPV);
- assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
- assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
- assert(PvNode || alpha == beta - 1);
- assert(depth <= 0);
+ assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
+ assert(PvNode == (alpha != beta - 1));
+ assert(depth <= DEPTH_ZERO);
assert(pos.thread() >= 0 && pos.thread() < Threads.size());
StateInfo st;
@@ -1328,7 +1207,7 @@ split_point_start: // At split points actual search starts from here
ss->ply = (ss-1)->ply + 1;
// Check for an instant draw or maximum ply reached
- if (pos.is_draw() || ss->ply > PLY_MAX)
+ if (pos.is_draw() || ss->ply > MAX_PLY)
return VALUE_DRAW;
// Decide whether or not to include checks, this fixes also the type of
@@ -1339,7 +1218,7 @@ split_point_start: // At split points actual search starts from here
// Transposition table lookup. At PV nodes, we don't use the TT for
// pruning, but only for move ordering.
- tte = TT.probe(pos.get_key());
+ tte = TT.probe(pos.key());
ttMove = (tte ? tte->move() : MOVE_NONE);
if (!PvNode && tte && can_return_tt(tte, ttDepth, beta, ss->ply))
@@ -1371,7 +1250,7 @@ split_point_start: // At split points actual search starts from here
if (bestValue >= beta)
{
if (!tte)
- TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
+ TT.store(pos.key(), value_to_tt(bestValue, ss->ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
return bestValue;
}
@@ -1379,7 +1258,6 @@ split_point_start: // At split points actual search starts from here
if (PvNode && bestValue > alpha)
alpha = bestValue;
- // Futility pruning parameters, not needed when in check
futilityBase = ss->eval + evalMargin + FutilityMarginQS;
enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame;
}
@@ -1388,12 +1266,12 @@ split_point_start: // At split points actual search starts from here
// to search the moves. Because the depth is <= 0 here, only captures,
// queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
// be generated.
- MovePicker mp(pos, ttMove, depth, H, move_to((ss-1)->currentMove));
+ MovePicker mp(pos, ttMove, depth, H, to_sq((ss-1)->currentMove));
CheckInfo ci(pos);
// Loop through the moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
- && (move = mp.get_next_move()) != MOVE_NONE)
+ && (move = mp.next_move()) != MOVE_NONE)
{
assert(is_ok(move));
@@ -1409,7 +1287,7 @@ split_point_start: // At split points actual search starts from here
&& !pos.is_passed_pawn_push(move))
{
futilityValue = futilityBase
- + PieceValueEndgame[pos.piece_on(move_to(move))]
+ + PieceValueEndgame[pos.piece_on(to_sq(move))]
+ (is_enpassant(move) ? PawnValueEndgame : VALUE_ZERO);
if (futilityValue < beta)
@@ -1430,7 +1308,7 @@ split_point_start: // At split points actual search starts from here
// Detect non-capture evasions that are candidate to be pruned
evasionPrunable = !PvNode
&& inCheck
- && bestValue > VALUE_MATED_IN_PLY_MAX
+ && bestValue > VALUE_MATED_IN_MAX_PLY
&& !pos.is_capture(move)
&& !pos.can_castle(pos.side_to_move());
@@ -1461,7 +1339,6 @@ split_point_start: // At split points actual search starts from here
if (!pos.pl_move_is_legal(move, ci.pinned))
continue;
- // Update current move
ss->currentMove = move;
// Make and search the move
@@ -1487,14 +1364,14 @@ split_point_start: // At split points actual search starts from here
// All legal moves have been searched. A special case: If we're in check
// and no legal moves were found, it is checkmate.
if (inCheck && bestValue == -VALUE_INFINITE)
- return value_mated_in(ss->ply);
+ return mated_in(ss->ply); // Plies to mate from the root
// Update transposition table
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER
: bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT;
- TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin);
+ TT.store(pos.key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
@@ -1514,9 +1391,9 @@ split_point_start: // At split points actual search starts from here
Color them;
Value futilityValue, bv = *bestValue;
- from = move_from(move);
- to = move_to(move);
- them = flip(pos.side_to_move());
+ from = from_sq(move);
+ to = to_sq(move);
+ them = ~pos.side_to_move();
ksq = pos.king_square(them);
kingAtt = pos.attacks_from(ksq);
pc = pos.piece_on(from);
@@ -1575,14 +1452,14 @@ split_point_start: // At split points actual search starts from here
assert(is_ok(m2));
// Case 1: The moving piece is the same in both moves
- f2 = move_from(m2);
- t1 = move_to(m1);
+ f2 = from_sq(m2);
+ t1 = to_sq(m1);
if (f2 == t1)
return true;
// Case 2: The destination square for m2 was vacated by m1
- t2 = move_to(m2);
- f1 = move_from(m1);
+ t2 = to_sq(m2);
+ f1 = from_sq(m1);
if (t2 == f1)
return true;
@@ -1612,30 +1489,31 @@ split_point_start: // At split points actual search starts from here
// value_to_tt() adjusts a mate score from "plies to mate from the root" to
- // "plies to mate from the current ply". Non-mate scores are unchanged.
+ // "plies to mate from the current position". Non-mate scores are unchanged.
// The function is called before storing a value to the transposition table.
Value value_to_tt(Value v, int ply) {
- if (v >= VALUE_MATE_IN_PLY_MAX)
+ if (v >= VALUE_MATE_IN_MAX_PLY)
return v + ply;
- if (v <= VALUE_MATED_IN_PLY_MAX)
+ if (v <= VALUE_MATED_IN_MAX_PLY)
return v - ply;
return v;
}
- // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score from
- // the transposition table to a mate score corrected for the current ply.
+ // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score
+ // from the transposition table (where refers to the plies to mate/be mated
+ // from current position) to "plies to mate/be mated from the root".
Value value_from_tt(Value v, int ply) {
- if (v >= VALUE_MATE_IN_PLY_MAX)
+ if (v >= VALUE_MATE_IN_MAX_PLY)
return v - ply;
- if (v <= VALUE_MATED_IN_PLY_MAX)
+ if (v <= VALUE_MATED_IN_MAX_PLY)
return v + ply;
return v;
@@ -1654,10 +1532,10 @@ split_point_start: // At split points actual search starts from here
Square mfrom, mto, tfrom, tto;
- mfrom = move_from(m);
- mto = move_to(m);
- tfrom = move_from(threat);
- tto = move_to(threat);
+ mfrom = from_sq(m);
+ mto = to_sq(m);
+ tfrom = from_sq(threat);
+ tto = to_sq(threat);
// Case 1: Don't prune moves which move the threatened piece
if (mfrom == tto)
@@ -1682,24 +1560,24 @@ split_point_start: // At split points actual search starts from here
}
- // can_return_tt() returns true if a transposition table score
- // can be used to cut-off at a given point in search.
+ // can_return_tt() returns true if a transposition table score can be used to
+ // cut-off at a given point in search.
bool can_return_tt(const TTEntry* tte, Depth depth, Value beta, int ply) {
Value v = value_from_tt(tte->value(), ply);
return ( tte->depth() >= depth
- || v >= std::max(VALUE_MATE_IN_PLY_MAX, beta)
- || v < std::min(VALUE_MATED_IN_PLY_MAX, beta))
+ || v >= std::max(VALUE_MATE_IN_MAX_PLY, beta)
+ || v < std::min(VALUE_MATED_IN_MAX_PLY, beta))
&& ( ((tte->type() & VALUE_TYPE_LOWER) && v >= beta)
|| ((tte->type() & VALUE_TYPE_UPPER) && v < beta));
}
- // refine_eval() returns the transposition table score if
- // possible otherwise falls back on static position evaluation.
+ // refine_eval() returns the transposition table score if possible, otherwise
+ // falls back on static position evaluation.
Value refine_eval(const TTEntry* tte, Value defaultEval, int ply) {
@@ -1715,38 +1593,17 @@ split_point_start: // At split points actual search starts from here
}
- // 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 move, Depth depth,
- Move movesSearched[], int moveCount) {
- Move m;
- Value bonus = Value(int(depth) * int(depth));
-
- H.update(pos.piece_on(move_from(move)), move_to(move), bonus);
-
- for (int i = 0; i < moveCount - 1; i++)
- {
- m = movesSearched[i];
-
- assert(m != move);
-
- H.update(pos.piece_on(move_from(m)), move_to(m), -bonus);
- }
- }
-
-
// current_search_time() returns the number of milliseconds which have passed
// since the beginning of the current search.
- int elapsed_search_time(int set) {
+ int elapsed_time(bool reset) {
static int searchStartTime;
- if (set)
- searchStartTime = set;
+ if (reset)
+ searchStartTime = system_time();
- return get_system_time() - searchStartTime;
+ return system_time() - searchStartTime;
}
@@ -1761,10 +1618,10 @@ split_point_start: // At split points actual search starts from here
std::stringstream s;
- if (abs(v) < VALUE_MATE - PLY_MAX * ONE_PLY)
- s << " score cp " << int(v) * 100 / int(PawnValueMidgame); // Scale to centipawns
+ if (abs(v) < VALUE_MATE_IN_MAX_PLY)
+ s << "cp " << v * 100 / int(PawnValueMidgame);
else
- s << " score mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
+ s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
s << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
@@ -1772,56 +1629,49 @@ split_point_start: // At split points actual search starts from here
}
- // speed_to_uci() returns a string with time stats of current search suitable
- // to be sent to UCI gui.
-
- string speed_to_uci(int64_t nodes) {
-
- std::stringstream s;
- int t = elapsed_search_time();
-
- s << " nodes " << nodes
- << " nps " << (t > 0 ? int(nodes * 1000 / t) : 0)
- << " time " << t;
-
- return s.str();
- }
+ // pv_info_to_uci() sends search info to GUI. UCI protocol requires to send all
+ // the PV lines also if are still to be searched and so refer to the previous
+ // search score.
+ void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta) {
- // pv_to_uci() returns a string with information on the current PV line
- // formatted according to UCI specification.
-
- string pv_to_uci(const Move pv[], int pvNum, bool chess960) {
-
- std::stringstream s;
-
- s << " multipv " << pvNum << " pv " << set960(chess960);
-
- for ( ; *pv != MOVE_NONE; pv++)
- s << *pv << " ";
-
- return s.str();
- }
-
-
- // depth_to_uci() returns a string with information on the current depth and
- // seldepth formatted according to UCI specification.
-
- string depth_to_uci(Depth depth) {
-
- std::stringstream s;
-
- // Retrieve max searched depth among threads
+ int t = elapsed_time();
int selDepth = 0;
+
for (int i = 0; i < Threads.size(); i++)
if (Threads[i].maxPly > selDepth)
selDepth = Threads[i].maxPly;
- s << " depth " << depth / ONE_PLY << " seldepth " << selDepth;
+ for (size_t i = 0; i < std::min(UCIMultiPV, RootMoves.size()); i++)
+ {
+ bool updated = (i <= PVIdx);
- return s.str();
+ if (depth == 1 && !updated)
+ continue;
+
+ int d = (updated ? depth : depth - 1);
+ Value v = (updated ? RootMoves[i].score : RootMoves[i].prevScore);
+ std::stringstream s;
+
+ for (int j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++)
+ s << " " << move_to_uci(RootMoves[i].pv[j], Chess960);
+
+ cout << "info depth " << d
+ << " seldepth " << selDepth
+ << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
+ << " nodes " << pos.nodes_searched()
+ << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0)
+ << " time " << t
+ << " multipv " << i + 1
+ << " pv" << s.str() << endl;
+ }
}
+
+ // pv_info_to_log() writes human-readable search information to the log file
+ // (which is created when the UCI parameter "Use Search Log" is "true"). It
+ // uses the two below helpers to pretty format time and score respectively.
+
string time_to_string(int millisecs) {
const int MSecMinute = 1000 * 60;
@@ -1836,7 +1686,8 @@ split_point_start: // At split points actual search starts from here
if (hours)
s << hours << ':';
- s << std::setfill('0') << std::setw(2) << minutes << ':' << std::setw(2) << seconds;
+ s << std::setfill('0') << std::setw(2) << minutes << ':'
+ << std::setw(2) << seconds;
return s.str();
}
@@ -1844,169 +1695,110 @@ split_point_start: // At split points actual search starts from here
std::stringstream s;
- if (v >= VALUE_MATE_IN_PLY_MAX)
+ if (v >= VALUE_MATE_IN_MAX_PLY)
s << "#" << (VALUE_MATE - v + 1) / 2;
- else if (v <= VALUE_MATED_IN_PLY_MAX)
+ else if (v <= VALUE_MATED_IN_MAX_PLY)
s << "-#" << (VALUE_MATE + v) / 2;
else
- s << std::setprecision(2) << std::fixed << std::showpos << float(v) / PawnValueMidgame;
+ s << std::setprecision(2) << std::fixed << std::showpos
+ << float(v) / PawnValueMidgame;
return s.str();
}
-
- // pretty_pv() creates a human-readable string from a position and a PV.
- // It is used to write search information to the log file (which is created
- // when the UCI parameter "Use Search Log" is "true").
-
- string pretty_pv(Position& pos, int depth, Value value, int time, Move pv[]) {
+ void pv_info_to_log(Position& pos, int depth, Value value, int time, Move pv[]) {
const int64_t K = 1000;
const int64_t M = 1000000;
- const int startColumn = 28;
- const size_t maxLength = 80 - startColumn;
- StateInfo state[PLY_MAX_PLUS_2], *st = state;
+ StateInfo state[MAX_PLY_PLUS_2], *st = state;
Move* m = pv;
- string san;
+ string san, padding;
+ size_t length;
std::stringstream s;
- size_t length = 0;
- // First print depth, score, time and searched nodes...
- s << set960(pos.is_chess960())
- << std::setw(2) << depth
+ s << std::setw(2) << depth
<< std::setw(8) << score_to_string(value)
<< std::setw(8) << time_to_string(time);
if (pos.nodes_searched() < M)
s << std::setw(8) << pos.nodes_searched() / 1 << " ";
+
else if (pos.nodes_searched() < K * M)
s << std::setw(7) << pos.nodes_searched() / K << "K ";
+
else
s << std::setw(7) << pos.nodes_searched() / M << "M ";
- // ...then print the full PV line in short algebraic notation
+ padding = string(s.str().length(), ' ');
+ length = padding.length();
+
while (*m != MOVE_NONE)
{
san = move_to_san(pos, *m);
- length += san.length() + 1;
- if (length > maxLength)
+ if (length + san.length() > 80)
{
- length = san.length() + 1;
- s << "\n" + string(startColumn, ' ');
+ s << "\n" + padding;
+ length = padding.length();
}
+
s << san << ' ';
+ length += san.length() + 1;
pos.do_move(*m++, *st++);
}
- // Restore original position before to leave
- while (m != pv) pos.undo_move(*--m);
+ while (m != pv)
+ pos.undo_move(*--m);
- return s.str();
- }
-
-
- // wait_for_stop_or_ponderhit() is called when the maximum depth is reached
- // while the program is pondering. The point is to work around a wrinkle in
- // the UCI protocol: When pondering, the engine is not allowed to give a
- // "bestmove" before the GUI sends it a "stop" or "ponderhit" command.
- // We simply wait here until one of these commands (that raise StopRequest) is
- // sent, and return, after which the bestmove and pondermove will be printed.
-
- void wait_for_stop_or_ponderhit() {
-
- string cmd;
- StopOnPonderhit = true;
-
- while (!StopRequest)
- {
- Threads.getline(cmd);
- do_uci_async_cmd(cmd);
- }
+ Log l(Options["Search Log Filename"]);
+ l << s.str() << endl;
}
// When playing with strength handicap choose best move among the MultiPV set
// using a statistical rule dependent on SkillLevel. Idea by Heinz van Saanen.
- void do_skill_level(Move* best, Move* ponder) {
+ Move do_skill_level() {
assert(MultiPV > 1);
static RKISS rk;
- // Rml list is already sorted by score in descending order
- int s;
- int max_s = -VALUE_INFINITE;
- int size = std::min(MultiPV, (int)Rml.size());
- int max = Rml[0].score;
- int var = std::min(max - Rml[size - 1].score, int(PawnValueMidgame));
- int wk = 120 - 2 * SkillLevel;
-
- // PRNG sequence should be non deterministic
- for (int i = abs(get_system_time() % 50); i > 0; i--)
+ // PRNG sequence should be not deterministic
+ for (int i = abs(system_time() % 50); i > 0; i--)
rk.rand();
- // Choose best move. For each move's score we add two terms both dependent
- // on wk, one deterministic and bigger for weaker moves, and one random,
+ // RootMoves are already sorted by score in descending order
+ size_t size = std::min(MultiPV, RootMoves.size());
+ int variance = std::min(RootMoves[0].score - RootMoves[size - 1].score, PawnValueMidgame);
+ int weakness = 120 - 2 * SkillLevel;
+ int max_s = -VALUE_INFINITE;
+ Move best = MOVE_NONE;
+
+ // Choose best move. For each move score we add two terms both dependent on
+ // weakness, one deterministic and bigger for weaker moves, and one random,
// then we choose the move with the resulting highest score.
- for (int i = 0; i < size; i++)
+ for (size_t i = 0; i < size; i++)
{
- s = Rml[i].score;
+ int s = RootMoves[i].score;
// Don't allow crazy blunders even at very low skills
- if (i > 0 && Rml[i-1].score > s + EasyMoveMargin)
+ if (i > 0 && RootMoves[i-1].score > s + EasyMoveMargin)
break;
- // This is our magical formula
- s += ((max - s) * wk + var * (rk.rand() % wk)) / 128;
+ // This is our magic formula
+ s += ( weakness * int(RootMoves[0].score - s)
+ + variance * (rk.rand() % weakness)) / 128;
if (s > max_s)
{
max_s = s;
- *best = Rml[i].pv[0];
- *ponder = Rml[i].pv[1];
+ best = RootMoves[i].pv[0];
}
}
- }
-
-
- /// RootMove and RootMoveList method's definitions
-
- void RootMoveList::init(Position& pos, Move searchMoves[]) {
-
- Move* sm;
- bestMoveChanges = 0;
- clear();
-
- // Generate all legal moves and add them to RootMoveList
- for (MoveList ml(pos); !ml.end(); ++ml)
- {
- // If we have a searchMoves[] list then verify the move
- // is in the list before to add it.
- for (sm = searchMoves; *sm && *sm != ml.move(); sm++) {}
-
- if (sm != searchMoves && *sm != ml.move())
- continue;
-
- RootMove rm;
- rm.pv.push_back(ml.move());
- rm.pv.push_back(MOVE_NONE);
- rm.score = rm.prevScore = -VALUE_INFINITE;
- rm.nodes = 0;
- push_back(rm);
- }
- }
-
- RootMove* RootMoveList::find(const Move& m, int startIndex) {
-
- for (size_t i = startIndex; i < size(); i++)
- if ((*this)[i].pv[0] == m)
- return &(*this)[i];
-
- return NULL;
+ return best;
}
@@ -2017,7 +1809,7 @@ split_point_start: // At split points actual search starts from here
void RootMove::extract_pv_from_tt(Position& pos) {
- StateInfo state[PLY_MAX_PLUS_2], *st = state;
+ StateInfo state[MAX_PLY_PLUS_2], *st = state;
TTEntry* tte;
int ply = 1;
Move m = pv[0];
@@ -2028,11 +1820,11 @@ split_point_start: // At split points actual search starts from here
pv.push_back(m);
pos.do_move(m, *st++);
- while ( (tte = TT.probe(pos.get_key())) != NULL
+ while ( (tte = TT.probe(pos.key())) != NULL
&& tte->move() != MOVE_NONE
&& pos.is_pseudo_legal(tte->move())
&& pos.pl_move_is_legal(tte->move(), pos.pinned_pieces())
- && ply < PLY_MAX
+ && ply < MAX_PLY
&& (!pos.is_draw() || ply < 2))
{
pv.push_back(tte->move());
@@ -2051,16 +1843,16 @@ split_point_start: // At split points actual search starts from here
void RootMove::insert_pv_in_tt(Position& pos) {
- StateInfo state[PLY_MAX_PLUS_2], *st = state;
+ StateInfo state[MAX_PLY_PLUS_2], *st = state;
TTEntry* tte;
Key k;
Value v, m = VALUE_NONE;
int ply = 0;
- assert(pv[0] != MOVE_NONE && pos.is_pseudo_legal(pv[0]));
+ assert(pv[ply] != MOVE_NONE && pos.is_pseudo_legal(pv[ply]));
do {
- k = pos.get_key();
+ k = pos.key();
tte = TT.probe(k);
// Don't overwrite existing correct entries
@@ -2079,9 +1871,9 @@ split_point_start: // At split points actual search starts from here
} // namespace
-// Thread::idle_loop() is where the thread is parked when it has no work to do.
-// The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint object
-// for which the thread is the master.
+/// Thread::idle_loop() is where the thread is parked when it has no work to do.
+/// The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint object
+/// for which the thread is the master.
void Thread::idle_loop(SplitPoint* sp) {
@@ -2095,7 +1887,6 @@ void Thread::idle_loop(SplitPoint* sp) {
{
assert((!sp && threadID) || Threads.use_sleeping_threads());
- // Slave thread should exit as soon as do_terminate flag raises
if (do_terminate)
{
assert(!sp);
@@ -2128,11 +1919,11 @@ void Thread::idle_loop(SplitPoint* sp) {
assert(!do_terminate);
// Copy split point position and search stack and call search()
- SearchStack ss[PLY_MAX_PLUS_2];
+ Stack ss[MAX_PLY_PLUS_2];
SplitPoint* tsp = splitPoint;
Position pos(*tsp->pos, threadID);
- memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack));
+ memcpy(ss, tsp->ss - 1, 4 * sizeof(Stack));
(ss+1)->sp = tsp;
if (tsp->nodeType == Root)
@@ -2170,59 +1961,33 @@ void Thread::idle_loop(SplitPoint* sp) {
}
-// do_uci_async_cmd() is called by listener thread when in async mode and 'cmd'
-// input line is received from the GUI.
+/// check_time() is called by the timer thread when the timer triggers. It is
+/// used to print debug info and, more important, to detect when we are out of
+/// available time and so stop the search.
-void do_uci_async_cmd(const std::string& cmd) {
-
- if (cmd == "quit")
- QuitRequest = StopRequest = true;
-
- else if (cmd == "stop")
- StopRequest = true;
-
- else if (cmd == "ponderhit")
- {
- // The opponent has played the expected move. GUI sends "ponderhit" if
- // we were told to ponder on the same move the opponent has played. We
- // should continue searching but switching from pondering to normal search.
- Limits.ponder = false;
-
- if (StopOnPonderhit)
- StopRequest = true;
- }
-}
-
-
-// do_timer_event() is called by the timer thread when the timer triggers
-
-void do_timer_event() {
+void check_time() {
static int lastInfoTime;
- int e = elapsed_search_time();
+ int e = elapsed_time();
- // Print debug information every one second
- if (!lastInfoTime || get_system_time() - lastInfoTime >= 1000)
+ if (system_time() - lastInfoTime >= 1000 || !lastInfoTime)
{
- lastInfoTime = get_system_time();
-
- dbg_print_mean();
- dbg_print_hit_rate();
+ lastInfoTime = system_time();
+ dbg_print();
}
- // Should we stop the search?
if (Limits.ponder)
return;
- bool stillAtFirstMove = FirstRootMove
- && !AspirationFailLow
+ bool stillAtFirstMove = Signals.firstRootMove
+ && !Signals.failedLowAtRoot
&& e > TimeMgr.available_time();
- bool noMoreTime = e > TimeMgr.maximum_time()
+ bool noMoreTime = e > TimeMgr.maximum_time() - 2 * TimerResolution
|| stillAtFirstMove;
- if ( (Limits.useTimeManagement() && noMoreTime)
+ if ( (Limits.use_time_management() && noMoreTime)
|| (Limits.maxTime && e >= Limits.maxTime)
/* missing nodes limit */ ) // FIXME
- StopRequest = true;
+ Signals.stop = true;
}