/*
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
Position RootPosition;
}
+using std::string;
using std::cout;
using std::endl;
-using std::string;
using namespace Search;
namespace {
RootMove(){}
RootMove(Move m) {
- nodes = 0;
score = prevScore = -VALUE_INFINITE;
pv.push_back(m);
pv.push_back(MOVE_NONE);
void extract_pv_from_tt(Position& pos);
void insert_pv_in_tt(Position& pos);
- int64_t nodes;
Value score;
Value prevScore;
std::vector<Move> pv;
/// Namespace variables
std::vector<RootMove> RootMoves;
- size_t MultiPV, UCIMultiPV, MultiPVIdx;
+ size_t MultiPV, UCIMultiPV, PVIdx;
TimeManager TimeMgr;
int BestMoveChanges;
int SkillLevel;
- bool SkillLevelEnabled;
+ bool SkillLevelEnabled, Chess960;
History H;
/// Local functions
- Move id_loop(Position& pos, Move* ponderMove);
-
template <NodeType NT>
Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth);
template <NodeType NT>
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);
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);
+ Move do_skill_level();
int elapsed_time(bool reset = false);
string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE);
void pv_info_to_log(Position& pos, int depth, Value score, int time, Move pv[]);
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) = f;
- return os;
- }
-
// 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) {
} // namespace
-/// init_search() is called during startup to initialize various lookup tables
+/// Search::init() is called during startup to initialize various lookup tables
void Search::init() {
}
-/// 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 Search::perft(Position& pos, Depth depth) {
}
-/// 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.
+/// 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.
void Search::think() {
static Book book; // Defined static to initialize the PRNG only once
Position& pos = RootPosition;
+ Chess960 = pos.is_chess960();
elapsed_time(true);
TimeMgr.init(Limits, pos.startpos_ply_counter());
-
- // Set output stream mode: normal or chess960. Castling notation is different
- cout << set960(pos.is_chess960());
-
- if (Options["OwnBook"].value<bool>())
+ 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<MV_LEGAL> 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<string>() != book.name())
- book.open(Options["Book File"].value<string>());
+ if (book.name() != (string)Options["Book File"])
+ book.open(Options["Book File"]);
- Move bookMove = book.probe(pos, Options["Best Book Move"].value<bool>());
- if (bookMove != MOVE_NONE)
- {
- if (!Signals.stop && (Limits.ponder || Limits.infinite))
- Threads.wait_for_stop_or_ponderhit();
+ Move bookMove = book.probe(pos, Options["Best Book Move"]);
- cout << "bestmove " << bookMove << endl;
- return;
+ if ( bookMove != MOVE_NONE
+ && count(RootMoves.begin(), RootMoves.end(), bookMove))
+ {
+ std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), bookMove));
+ goto finish;
}
}
read_evaluation_uci_options(pos.side_to_move());
Threads.read_uci_options();
- TT.set_size(Options["Hash"].value<int>());
- if (Options["Clear Hash"].value<bool>())
+ 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<size_t>();
- SkillLevel = Options["Skill Level"].value<int>();
+ 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, (size_t)4) : UCIMultiPV);
- if (Options["Use Search Log"].value<bool>())
+ if (Options["Use Search Log"])
{
- Log log(Options["Search Log Filename"].value<string>());
+ Log log(Options["Search Log Filename"]);
log << "\nSearching: " << pos.to_fen()
<< "\ninfinite: " << Limits.infinite
<< " ponder: " << Limits.ponder
<< endl;
}
- // Wake up needed threads and reset maxPly counter
for (int i = 0; i < Threads.size(); i++)
{
Threads[i].maxPly = 0;
else
Threads.set_timer(100);
- // We're ready to start thinking. Call the iterative deepening loop function
- Move ponderMove = MOVE_NONE;
- Move bestMove = id_loop(pos, &ponderMove);
+ // We're ready to start searching. Call the iterative deepening loop function
+ id_loop(pos);
// Stop timer and send all the slaves to sleep, if not already sleeping
Threads.set_timer(0);
Threads.set_size(1);
- if (Options["Use Search Log"].value<bool>())
+ if (Options["Use Search Log"])
{
int e = elapsed_time();
- Log log(Options["Search Log Filename"].value<string>());
+ 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]);
}
+finish:
+
// 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 (!Signals.stop && (Limits.ponder || Limits.infinite))
Threads.wait_for_stop_or_ponderhit();
- // Could be MOVE_NONE when searching on a stalemate position
- cout << "bestmove " << bestMove;
-
- // 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;
+ // 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;
}
// 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* ponderMove) {
+ void id_loop(Position& pos) {
Stack ss[PLY_MAX_PLUS_2];
- int bestMoveChanges[PLY_MAX_PLUS_2];
- int depth;
+ int depth, prevBestMoveChanges;
Value bestValue, alpha, beta, delta;
- Move bestMove, skillBest, skillPonder;
bool bestMoveNeverChanged = true;
+ Move skillBest = MOVE_NONE;
memset(ss, 0, 4 * sizeof(Stack));
- TT.new_search();
- H.clear();
- RootMoves.clear();
- *ponderMove = bestMove = skillBest = skillPonder = MOVE_NONE;
- depth = 0;
- bestValue = alpha = -VALUE_INFINITE, beta = delta = VALUE_INFINITE;
+ depth = BestMoveChanges = 0;
+ bestValue = delta = -VALUE_INFINITE;
ss->currentMove = MOVE_NULL; // Hack to skip update gains
- for (MoveList<MV_LEGAL> ml(pos); !ml.end(); ++ml)
- if ( SearchMoves.empty()
- || std::count(SearchMoves.begin(), SearchMoves.end(), ml.move()))
- RootMoves.push_back(RootMove(ml.move()));
-
- // Handle special case of searching on a mate/stalemate position
+ // Handle the special case of a mated/stalemate position
if (RootMoves.empty())
{
- cout << "info depth 0"
- << 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 (!Signals.stop && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth))
{
- // Save now last iteration's scores, before Rml moves are reordered
+ // 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;
+ prevBestMoveChanges = BestMoveChanges;
BestMoveChanges = 0;
// MultiPV loop. We perform a full root search for each PV line
- for (MultiPVIdx = 0; MultiPVIdx < std::min(MultiPV, RootMoves.size()); MultiPVIdx++)
+ for (PVIdx = 0; PVIdx < std::min(MultiPV, RootMoves.size()); PVIdx++)
{
- // Aspiration window
- if (depth >= 5 && abs(RootMoves[MultiPVIdx].prevScore) < VALUE_KNOWN_WIN)
+ // Set aspiration window default width
+ if (depth >= 5 && abs(RootMoves[PVIdx].prevScore) < VALUE_KNOWN_WIN)
{
delta = Value(16);
- alpha = RootMoves[MultiPVIdx].prevScore - delta;
- beta = RootMoves[MultiPVIdx].prevScore + delta;
+ alpha = RootMoves[PVIdx].prevScore - delta;
+ beta = RootMoves[PVIdx].prevScore + delta;
}
else
{
// 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<RootMove>(RootMoves.begin() + MultiPVIdx, RootMoves.end());
+ sort<RootMove>(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<RootMove>(RootMoves.begin(), RootMoves.begin() + MultiPVIdx);
+ if (PVIdx && bestValue > alpha && bestValue < beta)
+ sort<RootMove>(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 <= MultiPVIdx; i++)
+ // 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,
- // note that sorting and writing PV back to TT is safe becuase
- // Rml is still valid, although refers to the previous iteration.
+ // 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;
} while (abs(bestValue) < VALUE_KNOWN_WIN);
}
- bestMove = RootMoves[0].pv[0];
- *ponderMove = RootMoves[0].pv[1];
- bestMoveChanges[depth] = 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<bool>())
+ 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 (!Signals.stop && !Signals.stopOnPonderhit && Limits.useTimeManagement())
{
- bool stop = false; // Local variable instead of the volatile Signals.stop
+ 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.
+ // 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;
|| 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<NonPV>(pos, ss+1, rBeta - 1, rBeta, (depth * ONE_PLY) / 2);
(ss+1)->skipNullMove = false;
}
}
- // 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;
}
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;
|| ss->ply > PLY_MAX) && !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;
}
// 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 ? RootMoves[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
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() == NO_PIECE_TYPE
&& !is_special(move))
{
Square to = move_to(move);
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));
// 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
+ && (move = mp.next_move()) != MOVE_NONE
&& !thread.cutoff_occurred())
{
assert(is_ok(move));
// 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 && !std::count(RootMoves.begin() + MultiPVIdx, RootMoves.end(), move))
+ 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
if (RootNode)
{
- // This is used by time management
Signals.firstRootMove = (moveCount == 1);
- nodes = pos.nodes_searched();
-
if (pos.thread() == 0 && elapsed_time() > 2000)
cout << "info depth " << depth / ONE_PLY
- << " currmove " << move
- << " currmovenumber " << moveCount + MultiPVIdx << endl;
+ << " currmove " << move_to_uci(move, Chess960)
+ << " currmovenumber " << moveCount + PVIdx << endl;
}
isPvMove = (PvNode && moveCount <= 1);
// be trusted, and we don't update the best move and/or PV.
if (RootNode && !Signals.stop)
{
- RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), 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)
// 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 (!moveCount)
- return excludedMove ? oldAlpha : inCheck ? value_mated_in(ss->ply) : VALUE_DRAW;
+ 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)
}
// Step 21. Update tables
- // Update transposition table entry, history and killers
+ // Update transposition table entry, killers and history
if (!SpNode && !Signals.stop && !thread.cutoff_occurred())
{
move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
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_on(move_from(move)), move_to(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_on(move_from(m)), move_to(m), -bonus);
+ }
}
}
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;
// 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))
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;
}
// 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));
// 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);
// 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) {
}
- // 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) {
}
- // 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.
static int searchStartTime;
if (reset)
- searchStartTime = get_system_time();
+ searchStartTime = system_time();
- return get_system_time() - searchStartTime;
+ return system_time() - searchStartTime;
}
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_PLY_MAX)
+ 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" : "");
for (size_t i = 0; i < std::min(UCIMultiPV, RootMoves.size()); i++)
{
- bool updated = (i <= MultiPVIdx);
+ bool updated = (i <= PVIdx);
if (depth == 1 && !updated)
continue;
int d = (updated ? depth : depth - 1);
- Value s = (updated ? RootMoves[i].score : RootMoves[i].prevScore);
+ Value v = (updated ? RootMoves[i].score : RootMoves[i].prevScore);
+ std::stringstream s;
- cout << "info"
- << " depth " << d
+ 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
- << (i == MultiPVIdx ? score_to_uci(s, alpha, beta) : score_to_uci(s))
+ << " 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";
-
- for (int j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++)
- cout << " " << RootMoves[i].pv[j];
-
- cout << endl;
+ << " multipv " << i + 1
+ << " pv" << s.str() << endl;
}
}
size_t length;
std::stringstream s;
- 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);
while (m != pv)
pos.undo_move(*--m);
- Log l(Options["Search Log Filename"].value<string>());
+ 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;
// PRNG sequence should be not deterministic
- for (int i = abs(get_system_time() % 50); i > 0; i--)
+ for (int i = abs(system_time() % 50); i > 0; i--)
rk.rand<unsigned>();
- // Rml list is already sorted by score in descending order
+ // 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,
if (s > max_s)
{
max_s = s;
- *best = RootMoves[i].pv[0];
- *ponder = RootMoves[i].pv[1];
+ best = RootMoves[i].pv[0];
}
}
+ return best;
}
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())
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
static int lastInfoTime;
int e = elapsed_time();
- if (get_system_time() - lastInfoTime >= 1000 || !lastInfoTime)
+ if (system_time() - lastInfoTime >= 1000 || !lastInfoTime)
{
- lastInfoTime = get_system_time();
+ lastInfoTime = system_time();
dbg_print_mean();
dbg_print_hit_rate();
projects / stockfish / blobdiff