#include <iomanip>
#include <iostream>
#include <sstream>
-#include <vector>
#include "book.h"
#include "evaluate.h"
#include "history.h"
-#include "misc.h"
#include "movegen.h"
#include "movepick.h"
#include "search.h"
volatile SignalsType Signals;
LimitsType Limits;
- std::vector<Move> SearchMoves;
+ std::vector<RootMove> RootMoves;
Position RootPosition;
+ Time SearchTime;
}
using std::string;
using std::cout;
using std::endl;
+using Eval::evaluate;
using namespace Search;
namespace {
// Different node types, used as template parameter
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.
- struct RootMove {
-
- 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);
-
- Value score;
- Value prevScore;
- std::vector<Move> pv;
- };
-
-
- /// Constants
-
// Lookup table to check if a Piece is a slider and its access function
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]; }
return (Depth) Reductions[PvNode][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)];
}
- // Easy move margin. An easy move candidate must be at least this much
- // better than the second best move.
+ // Easy move margin. An easy move candidate must be at least this much 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
- std::vector<RootMove> RootMoves;
size_t MultiPV, UCIMultiPV, PVIdx;
TimeManager TimeMgr;
int BestMoveChanges;
History H;
- /// Local functions
-
template <NodeType NT>
Value search(Position& pos, Stack* 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 check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta);
bool connected_moves(const Position& pos, Move m1, Move m2);
Value value_to_tt(Value v, int ply);
Value value_from_tt(Value v, int ply);
- bool can_return_tt(const TTEntry* tte, Depth depth, Value beta, int ply);
+ bool can_return_tt(const TTEntry* tte, Depth depth, Value ttValue, Value beta);
bool connected_threat(const Position& pos, Move m, Move threat);
- Value refine_eval(const TTEntry* tte, Value defaultEval, int ply);
+ Value refine_eval(const TTEntry* tte, Value ttValue, Value defaultEval);
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[]);
void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta);
FORCE_INLINE bool is_dangerous(const Position& pos, Move m, bool captureOrPromotion) {
// Test for a pawn pushed to 7th or a passed pawn move
- if (type_of(pos.piece_on(move_from(m))) == PAWN)
+ if (type_of(pos.piece_moved(m)) == PAWN)
{
Color c = pos.side_to_move();
- if ( relative_rank(c, move_to(m)) == RANK_7
- || pos.pawn_is_passed(c, move_to(m)))
+ 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))
return true;
Position& pos = RootPosition;
Chess960 = pos.is_chess960();
- elapsed_time(true);
- TimeMgr.init(Limits, pos.startpos_ply_counter());
+ Eval::RootColor = pos.side_to_move();
+ TimeMgr.init(Limits, pos.startpos_ply_counter(), pos.side_to_move());
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 (RootMoves.empty())
+ {
+ cout << "info depth 0 score "
+ << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl;
+
+ RootMoves.push_back(MOVE_NONE);
+ goto finalize;
+ }
if (Options["OwnBook"])
{
Move bookMove = book.probe(pos, Options["Book File"], Options["Best Book Move"]);
- if ( bookMove != MOVE_NONE
- && count(RootMoves.begin(), RootMoves.end(), bookMove))
+ if (bookMove && count(RootMoves.begin(), RootMoves.end(), bookMove))
{
std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), bookMove));
- goto finish;
+ goto finalize;
}
}
- // Read UCI options: GUI could change UCI parameters during the game
- read_evaluation_uci_options(pos.side_to_move());
- Threads.read_uci_options();
-
- TT.set_size(Options["Hash"]);
- if (Options["Clear Hash"])
- {
- Options["Clear Hash"] = false;
- TT.clear();
- }
-
UCIMultiPV = Options["MultiPV"];
SkillLevel = Options["Skill Level"];
log << "\nSearching: " << pos.to_fen()
<< "\ninfinite: " << Limits.infinite
<< " ponder: " << Limits.ponder
- << " time: " << Limits.time
- << " increment: " << Limits.increment
- << " moves to go: " << Limits.movesToGo
+ << " time: " << Limits.time[pos.side_to_move()]
+ << " increment: " << Limits.inc[pos.side_to_move()]
+ << " moves to go: " << Limits.movestogo
<< endl;
}
- for (int i = 0; i < Threads.size(); i++)
- {
- Threads[i].maxPly = 0;
- Threads[i].wake_up();
- }
+ Threads.wake_up();
// Set best timer interval to avoid lagging under time pressure. Timer is
// used to check for remaining available thinking time.
- 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);
// 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);
+ Threads.set_timer(0); // Stop timer
+ Threads.sleep();
if (Options["Use Search Log"])
{
- int e = elapsed_time();
+ int e = SearchTime.elapsed();
Log log(Options["Search Log Filename"]);
log << "Nodes: " << pos.nodes_searched()
pos.undo_move(RootMoves[0].pv[0]);
}
-finish:
+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.
+ // When we reach max depth we arrive here even without Signals.stop is raised,
+ // 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();
+ Threads[pos.this_thread()].wait_for_stop_or_ponderhit();
// Best move could be MOVE_NONE when searching on a stalemate position
cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960)
bestValue = delta = -VALUE_INFINITE;
ss->currentMove = MOVE_NULL; // Hack to skip update gains
- // Handle the special case of a mated/stalemate position
- if (RootMoves.empty())
- {
- cout << "info depth 0 score "
- << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl;
-
- RootMoves.push_back(MOVE_NONE);
- return;
- }
-
// Iterative deepening loop until requested to stop or target depth reached
- while (!Signals.stop && ++depth <= MAX_PLY && (!Limits.maxDepth || depth <= Limits.maxDepth))
+ while (!Signals.stop && ++depth <= MAX_PLY && (!Limits.depth || depth <= Limits.depth))
{
// 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.
// 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.
- if ((bestValue > alpha && bestValue < beta) || elapsed_time() > 2000)
+ if ((bestValue > alpha && bestValue < beta) || SearchTime.elapsed() > 2000)
pv_info_to_uci(pos, depth, alpha, beta);
// In case of failing high/low increase aspiration window and
if (SkillLevelEnabled && depth == 1 + SkillLevel)
skillBest = do_skill_level();
- if (Options["Use Search Log"])
- pv_info_to_log(pos, depth, bestValue, elapsed_time(), &RootMoves[0].pv[0]);
+ if (!Signals.stop && Options["Use Search Log"])
+ pv_info_to_log(pos, depth, bestValue, SearchTime.elapsed(), &RootMoves[0].pv[0]);
// Filter out startup noise when monitoring best move stability
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())
+ if (!Signals.stop && !Signals.stopOnPonderhit && Limits.use_time_management())
{
bool stop = false; // Local variable, not the volatile Signals.stop
// 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)
+ if (SearchTime.elapsed() > (TimeMgr.available_time() * 62) / 100)
stop = true;
// Stop search early if one move seems to be much better than others
- if ( depth >= 10
+ if ( depth >= 12
&& !stop
- && ( bestMoveNeverChanged
- || elapsed_time() > (TimeMgr.available_time() * 40) / 100))
+ && ( (bestMoveNeverChanged && pos.captured_piece_type())
+ || SearchTime.elapsed() > (TimeMgr.available_time() * 40) / 100))
{
Value rBeta = bestValue - EasyMoveMargin;
(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);
+ Value v = search<NonPV>(pos, ss+1, rBeta - 1, rBeta, (depth - 3) * ONE_PLY);
(ss+1)->skipNullMove = false;
(ss+1)->excludedMove = MOVE_NONE;
const bool RootNode = (NT == Root || NT == SplitPointRoot);
assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
- assert(PvNode == (alpha != beta - 1));
+ assert((alpha == beta - 1) || PvNode);
assert(depth > DEPTH_ZERO);
- assert(pos.thread() >= 0 && pos.thread() < Threads.size());
+ assert(pos.this_thread() >= 0 && pos.this_thread() < Threads.size());
Move movesSearched[MAX_MOVES];
StateInfo st;
const TTEntry *tte;
Key posKey;
- Move ttMove, move, excludedMove, threatMove;
+ Move ttMove, move, excludedMove, bestMove, threatMove;
Depth ext, newDepth;
- ValueType vt;
- Value bestValue, value, oldAlpha;
+ Bound bt;
+ Value bestValue, value, oldAlpha, ttValue;
Value refinedValue, nullValue, futilityBase, futilityValue;
bool isPvMove, inCheck, singularExtensionNode, givesCheck;
bool captureOrPromotion, dangerous, doFullDepthSearch;
int moveCount = 0, playedMoveCount = 0;
- Thread& thread = Threads[pos.thread()];
+ Thread& thread = Threads[pos.this_thread()];
SplitPoint* sp = NULL;
refinedValue = bestValue = value = -VALUE_INFINITE;
thread.maxPly = ss->ply;
// Step 1. Initialize node
- if (!SpNode)
- {
- ss->currentMove = ss->bestMove = threatMove = (ss+1)->excludedMove = MOVE_NONE;
- (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
- (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
- }
- else
+ if (SpNode)
{
- sp = ss->sp;
tte = NULL;
ttMove = excludedMove = MOVE_NONE;
+ ttValue = VALUE_ZERO;
+ sp = ss->sp;
+ bestMove = sp->bestMove;
threatMove = sp->threatMove;
+ bestValue = sp->bestValue;
+ moveCount = sp->moveCount; // Lock must be held here
+
+ assert(bestValue > -VALUE_INFINITE && moveCount > 0);
+
goto split_point_start;
}
+ else
+ {
+ ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
+ (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
+ (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
+
+ }
// Step 2. Check for aborted search and immediate draw
+ // Enforce node limit here. FIXME: This only works with 1 search thread.
+ if (Limits.nodes && pos.nodes_searched() >= Limits.nodes)
+ Signals.stop = true;
+
if (( Signals.stop
|| pos.is_draw<false>()
|| ss->ply > MAX_PLY) && !RootNode)
posKey = excludedMove ? pos.exclusion_key() : pos.key();
tte = TT.probe(posKey);
ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE;
+ ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_ZERO;
// 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
// smooth experience in analysis mode. We don't probe at Root nodes otherwise
// we should also update RootMoveList to avoid bogus output.
- if (!RootNode && tte && (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT
- : can_return_tt(tte, depth, beta, ss->ply)))
+ if (!RootNode && tte && (PvNode ? tte->depth() >= depth && tte->type() == BOUND_EXACT
+ : can_return_tt(tte, depth, ttValue, beta)))
{
TT.refresh(tte);
- ss->bestMove = move = ttMove; // Can be MOVE_NONE
- value = value_from_tt(tte->value(), ss->ply);
+ ss->currentMove = ttMove; // Can be MOVE_NONE
- if ( value >= beta
- && move
- && !pos.is_capture_or_promotion(move)
- && move != ss->killers[0])
+ if ( ttValue >= beta
+ && ttMove
+ && !pos.is_capture_or_promotion(ttMove)
+ && ttMove != ss->killers[0])
{
ss->killers[1] = ss->killers[0];
- ss->killers[0] = move;
+ ss->killers[0] = ttMove;
}
- return value;
+ return ttValue;
}
// Step 5. Evaluate the position statically and update parent's gain statistics
ss->eval = tte->static_value();
ss->evalMargin = tte->static_value_margin();
- refinedValue = refine_eval(tte, ss->eval, ss->ply);
+ refinedValue = refine_eval(tte, ttValue, ss->eval);
}
else
{
refinedValue = ss->eval = evaluate(pos, ss->evalMargin);
- TT.store(posKey, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, MOVE_NONE, ss->eval, ss->evalMargin);
+ TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->eval, ss->evalMargin);
}
// Update gain for the parent non-capture move given the static position
if ( (move = (ss-1)->currentMove) != MOVE_NULL
&& (ss-1)->eval != VALUE_NONE
&& ss->eval != VALUE_NONE
- && pos.captured_piece_type() == NO_PIECE_TYPE
+ && !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);
}
&& refinedValue + razor_margin(depth) < beta
&& ttMove == MOVE_NONE
&& abs(beta) < VALUE_MATE_IN_MAX_PLY
- && !pos.has_pawn_on_7th(pos.side_to_move()))
+ && !pos.pawn_on_7th(pos.side_to_move()))
{
Value rbeta = beta - razor_margin(depth);
Value v = qsearch<NonPV>(pos, ss, rbeta-1, rbeta, DEPTH_ZERO);
// move which was reduced. If a connection is found, return a fail
// low score (which will cause the reduced move to fail high in the
// parent node, which will trigger a re-search with full depth).
- threatMove = (ss+1)->bestMove;
+ threatMove = (ss+1)->currentMove;
if ( depth < ThreatDepth
&& (ss-1)->reduction
Depth rdepth = depth - ONE_PLY - 3 * ONE_PLY;
assert(rdepth >= ONE_PLY);
+ assert((ss-1)->currentMove != MOVE_NONE);
+ assert((ss-1)->currentMove != MOVE_NULL);
MovePicker mp(pos, ttMove, H, pos.captured_piece_type());
CheckInfo ci(pos);
while ((move = mp.next_move()) != MOVE_NONE)
if (pos.pl_move_is_legal(move, ci.pinned))
{
+ ss->currentMove = move;
pos.do_move(move, st, ci, pos.move_gives_check(move, ci));
value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, rdepth);
pos.undo_move(move);
MovePickerExt<SpNode> mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta);
CheckInfo ci(pos);
- ss->bestMove = MOVE_NONE;
futilityBase = ss->eval + ss->evalMargin;
singularExtensionNode = !RootNode
&& !SpNode
&& depth >= SingularExtensionDepth[PvNode]
&& ttMove != MOVE_NONE
&& !excludedMove // Recursive singular search is not allowed
- && (tte->type() & VALUE_TYPE_LOWER)
+ && (tte->type() & BOUND_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.next_move()) != MOVE_NONE
- && !thread.cutoff_occurred())
+ && !thread.cutoff_occurred()
+ && !Signals.stop)
{
assert(is_ok(move));
if (SpNode)
{
moveCount = ++sp->moveCount;
- lock_release(&(sp->lock));
+ lock_release(sp->lock);
}
else
moveCount++;
{
Signals.firstRootMove = (moveCount == 1);
- if (pos.thread() == 0 && elapsed_time() > 2000)
+ if (pos.this_thread() == 0 && SearchTime.elapsed() > 2000)
cout << "info depth " << depth / ONE_PLY
<< " currmove " << move_to_uci(move, Chess960)
<< " currmovenumber " << moveCount + PVIdx << endl;
&& move == ttMove
&& pos.pl_move_is_legal(move, ci.pinned))
{
- Value ttValue = value_from_tt(tte->value(), ss->ply);
-
if (abs(ttValue) < VALUE_KNOWN_WIN)
{
Value rBeta = ttValue - int(depth);
value = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth / 2);
ss->skipNullMove = false;
ss->excludedMove = MOVE_NONE;
- ss->bestMove = MOVE_NONE;
if (value < rBeta)
ext = ONE_PLY;
}
&& (!threatMove || !connected_threat(pos, move, threatMove)))
{
if (SpNode)
- lock_grab(&(sp->lock));
+ lock_grab(sp->lock);
continue;
}
// but fixing this made program slightly weaker.
Depth predictedDepth = newDepth - reduction<PvNode>(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));
+ lock_grab(sp->lock);
continue;
}
&& pos.see_sign(move) < 0)
{
if (SpNode)
- lock_grab(&(sp->lock));
+ lock_grab(sp->lock);
continue;
}
&& ss->killers[1] != move)
{
ss->reduction = reduction<PvNode>(depth, moveCount);
- Depth d = newDepth - ss->reduction;
+ Depth d = std::max(newDepth - ss->reduction, ONE_PLY);
alpha = SpNode ? sp->alpha : alpha;
- value = d < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
- : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO);
ss->reduction = DEPTH_ZERO;
// Step 18. Check for new best move
if (SpNode)
{
- lock_grab(&(sp->lock));
+ lock_grab(sp->lock);
bestValue = sp->bestValue;
alpha = sp->alpha;
}
- // Finished searching the move. If StopRequest is true, the search
+ // Finished searching the move. If Signals.stop is true, the search
// was aborted because the user interrupted the search or because we
// ran out of time. In this case, the return value of the search cannot
// be trusted, and we don't update the best move and/or PV.
if (value > bestValue)
{
bestValue = value;
- ss->bestMove = move;
+ bestMove = move;
if ( PvNode
&& value > alpha
if (SpNode && !thread.cutoff_occurred())
{
sp->bestValue = value;
- sp->ss->bestMove = move;
+ sp->bestMove = move;
sp->alpha = alpha;
- sp->is_betaCutoff = (value >= beta);
+
+ if (value >= beta)
+ sp->cutoff = true;
}
}
if ( !SpNode
&& depth >= Threads.min_split_depth()
&& bestValue < beta
- && Threads.available_slave_exists(pos.thread())
+ && Threads.available_slave_exists(pos.this_thread())
&& !Signals.stop
&& !thread.cutoff_occurred())
- bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, depth,
- threatMove, moveCount, &mp, NT);
+ bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, &bestMove,
+ depth, threatMove, moveCount, &mp, NT);
}
// Step 20. Check for mate and stalemate
// All legal moves have been searched and if there are no legal moves, it
// must be mate or stalemate. Note that we can have a false positive in
- // case of StopRequest or thread.cutoff_occurred() are set, but this is
+ // case of Signals.stop 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 (!moveCount)
{
assert(!playedMoveCount);
- bestValue = alpha;
+ bestValue = oldAlpha;
}
// Step 21. Update tables
// 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
- : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT;
+ move = bestValue <= oldAlpha ? MOVE_NONE : bestMove;
+ bt = bestValue <= oldAlpha ? BOUND_UPPER
+ : bestValue >= beta ? BOUND_LOWER : BOUND_EXACT;
- TT.store(posKey, value_to_tt(bestValue, ss->ply), vt, depth, move, ss->eval, ss->evalMargin);
+ TT.store(posKey, value_to_tt(bestValue, ss->ply), bt, depth, move, ss->eval, ss->evalMargin);
// Update killers and history for non capture cut-off moves
if ( bestValue >= beta
// 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);
+ 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_on(move_from(m)), move_to(m), -bonus);
+ H.add(pos.piece_moved(m), to_sq(m), -bonus);
}
}
}
- if (SpNode)
- {
- // Here we have the lock still grabbed
- sp->is_slave[pos.thread()] = false;
- sp->nodes += pos.nodes_searched();
- lock_release(&(sp->lock));
- }
-
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
return bestValue;
assert(NT == PV || NT == NonPV);
assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
- assert(PvNode == (alpha != beta - 1));
+ assert((alpha == beta - 1) || PvNode);
assert(depth <= DEPTH_ZERO);
- assert(pos.thread() >= 0 && pos.thread() < Threads.size());
+ assert(pos.this_thread() >= 0 && pos.this_thread() < Threads.size());
StateInfo st;
- Move ttMove, move;
- Value bestValue, value, evalMargin, futilityValue, futilityBase;
+ Move ttMove, move, bestMove;
+ Value ttValue, bestValue, value, evalMargin, futilityValue, futilityBase;
bool inCheck, enoughMaterial, givesCheck, evasionPrunable;
const TTEntry* tte;
Depth ttDepth;
- ValueType vt;
+ Bound bt;
Value oldAlpha = alpha;
- ss->bestMove = ss->currentMove = MOVE_NONE;
+ ss->currentMove = bestMove = MOVE_NONE;
ss->ply = (ss-1)->ply + 1;
// Check for an instant draw or maximum ply reached
// pruning, but only for move ordering.
tte = TT.probe(pos.key());
ttMove = (tte ? tte->move() : MOVE_NONE);
+ ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_ZERO;
- if (!PvNode && tte && can_return_tt(tte, ttDepth, beta, ss->ply))
+ if (!PvNode && tte && can_return_tt(tte, ttDepth, ttValue, beta))
{
- ss->bestMove = ttMove; // Can be MOVE_NONE
- return value_from_tt(tte->value(), ss->ply);
+ ss->currentMove = ttMove; // Can be MOVE_NONE
+ return ttValue;
}
// Evaluate the position statically
if (bestValue >= beta)
{
if (!tte)
- TT.store(pos.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), BOUND_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
return bestValue;
}
// 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
&& !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)
&& move != ttMove
&& !pos.is_capture_or_promotion(move)
&& ss->eval + PawnValueMidgame / 4 < beta
- && !check_is_dangerous(pos, move, futilityBase, beta, &bestValue))
- {
- if (ss->eval + PawnValueMidgame / 4 > bestValue)
- bestValue = ss->eval + PawnValueMidgame / 4;
-
+ && !check_is_dangerous(pos, move, futilityBase, beta))
continue;
- }
// Check for legality only before to do the move
if (!pos.pl_move_is_legal(move, ci.pinned))
if (value > bestValue)
{
bestValue = value;
- ss->bestMove = move;
+ bestMove = move;
if ( PvNode
&& value > alpha
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;
+ move = bestValue <= oldAlpha ? MOVE_NONE : bestMove;
+ bt = bestValue <= oldAlpha ? BOUND_UPPER
+ : bestValue >= beta ? BOUND_LOWER : BOUND_EXACT;
- TT.store(pos.key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin);
+ TT.store(pos.key(), value_to_tt(bestValue, ss->ply), bt, ttDepth, move, ss->eval, evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
// bestValue is updated only when returning false because in that case move
// will be pruned.
- bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bestValue)
+ bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta)
{
Bitboard b, occ, oldAtt, newAtt, kingAtt;
- Square from, to, ksq, victimSq;
+ Square from, to, ksq;
Piece pc;
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<KING>(ksq);
- pc = pos.piece_on(from);
+ pc = pos.piece_moved(move);
- occ = pos.occupied_squares() & ~(1ULL << from) & ~(1ULL << ksq);
+ occ = pos.pieces() ^ from ^ ksq;
oldAtt = pos.attacks_from(pc, from, occ);
newAtt = pos.attacks_from(pc, to, occ);
// Rule 1. Checks which give opponent's king at most one escape square are dangerous
b = kingAtt & ~pos.pieces(them) & ~newAtt & ~(1ULL << to);
- if (!(b && (b & (b - 1))))
+ if (single_bit(b)) // Catches also !b
return true;
// Rule 2. Queen contact check is very dangerous
- if ( type_of(pc) == QUEEN
- && bit_is_set(kingAtt, to))
+ if (type_of(pc) == QUEEN && (kingAtt & to))
return true;
// Rule 3. Creating new double threats with checks
b = pos.pieces(them) & newAtt & ~oldAtt & ~(1ULL << ksq);
-
while (b)
{
- victimSq = pop_1st_bit(&b);
- futilityValue = futilityBase + PieceValueEndgame[pos.piece_on(victimSq)];
-
// Note that here we generate illegal "double move"!
- if ( futilityValue >= beta
- && pos.see_sign(make_move(from, victimSq)) >= 0)
+ if (futilityBase + PieceValueEndgame[pos.piece_on(pop_1st_bit(&b))] >= beta)
return true;
-
- if (futilityValue > bv)
- bv = futilityValue;
}
- // Update bestValue only if check is not dangerous (because we will prune the move)
- *bestValue = bv;
return false;
}
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;
// Case 3: Moving through the vacated square
p2 = pos.piece_on(f2);
- if ( piece_is_slider(p2)
- && bit_is_set(squares_between(f2, t2), f1))
+ if (piece_is_slider(p2) && (squares_between(f2, t2) & f1))
return true;
// Case 4: The destination square for m2 is defended by the moving piece in m1
p1 = pos.piece_on(t1);
- if (bit_is_set(pos.attacks_from(p1, t1), t2))
+ if (pos.attacks_from(p1, t1) & t2)
return true;
// Case 5: Discovered check, checking piece is the piece moved in m1
ksq = pos.king_square(pos.side_to_move());
if ( piece_is_slider(p1)
- && bit_is_set(squares_between(t1, ksq), f2))
- {
- Bitboard occ = pos.occupied_squares();
- clear_bit(&occ, f2);
- if (bit_is_set(pos.attacks_from(p1, t1, occ), ksq))
- return true;
- }
+ && (squares_between(t1, ksq) & f2)
+ && (pos.attacks_from(p1, t1, pos.pieces() ^ f2) & ksq))
+ return true;
+
return false;
}
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)
// Case 3: If the moving piece in the threatened move is a slider, don't
// prune safe moves which block its ray.
- if ( piece_is_slider(pos.piece_on(tfrom))
- && bit_is_set(squares_between(tfrom, tto), mto)
- && pos.see_sign(m) >= 0)
+ if ( piece_is_slider(pos.piece_on(tfrom))
+ && (squares_between(tfrom, tto) & mto)
+ && pos.see_sign(m) >= 0)
return true;
return false;
// 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);
+ bool can_return_tt(const TTEntry* tte, Depth depth, Value v, Value beta) {
return ( tte->depth() >= depth
|| 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));
+ && ( ((tte->type() & BOUND_LOWER) && v >= beta)
+ || ((tte->type() & BOUND_UPPER) && v < beta));
}
// 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) {
+ Value refine_eval(const TTEntry* tte, Value v, Value defaultEval) {
assert(tte);
- Value v = value_from_tt(tte->value(), ply);
-
- if ( ((tte->type() & VALUE_TYPE_LOWER) && v >= defaultEval)
- || ((tte->type() & VALUE_TYPE_UPPER) && v < defaultEval))
+ if ( ((tte->type() & BOUND_LOWER) && v >= defaultEval)
+ || ((tte->type() & BOUND_UPPER) && v < defaultEval))
return v;
return defaultEval;
}
- // current_search_time() returns the number of milliseconds which have passed
- // since the beginning of the current search.
-
- int elapsed_time(bool reset) {
-
- static int searchStartTime;
-
- if (reset)
- searchStartTime = system_time();
-
- return system_time() - searchStartTime;
- }
-
-
// score_to_uci() converts a value to a string suitable for use with the UCI
// protocol specifications:
//
void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta) {
- int t = elapsed_time();
+ int t = SearchTime.elapsed();
int selDepth = 0;
for (int i = 0; i < Threads.size(); i++)
static RKISS rk;
// PRNG sequence should be not deterministic
- for (int i = abs(system_time() % 50); i > 0; i--)
+ for (int i = Time::current_time().msec() % 50; i > 0; i--)
rk.rand<unsigned>();
// RootMoves are already sorted by score in descending order
return best;
}
+} // namespace
- // extract_pv_from_tt() builds a PV by adding moves from the transposition table.
- // We consider also failing high nodes and not only VALUE_TYPE_EXACT nodes. This
- // allow to always have a ponder move even when we fail high at root and also a
- // long PV to print that is important for position analysis.
- void RootMove::extract_pv_from_tt(Position& pos) {
+/// RootMove::extract_pv_from_tt() builds a PV by adding moves from the TT table.
+/// We consider also failing high nodes and not only BOUND_EXACT nodes so to
+/// allow to always have a ponder move even when we fail high at root, and a
+/// long PV to print that is important for position analysis.
- StateInfo state[MAX_PLY_PLUS_2], *st = state;
- TTEntry* tte;
- int ply = 1;
- Move m = pv[0];
-
- assert(m != MOVE_NONE && pos.is_pseudo_legal(m));
-
- pv.clear();
- pv.push_back(m);
- pos.do_move(m, *st++);
-
- 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 < MAX_PLY
- && (!pos.is_draw<false>() || ply < 2))
- {
- pv.push_back(tte->move());
- pos.do_move(tte->move(), *st++);
- ply++;
- }
- pv.push_back(MOVE_NONE);
+void RootMove::extract_pv_from_tt(Position& pos) {
+
+ StateInfo state[MAX_PLY_PLUS_2], *st = state;
+ TTEntry* tte;
+ int ply = 1;
+ Move m = pv[0];
+
+ assert(m != MOVE_NONE && pos.is_pseudo_legal(m));
+
+ pv.clear();
+ pv.push_back(m);
+ pos.do_move(m, *st++);
- do pos.undo_move(pv[--ply]); while (ply);
+ while ( (tte = TT.probe(pos.key())) != NULL
+ && (m = tte->move()) != MOVE_NONE // Local copy, TT entry could change
+ && pos.is_pseudo_legal(m)
+ && pos.pl_move_is_legal(m, pos.pinned_pieces())
+ && ply < MAX_PLY
+ && (!pos.is_draw<false>() || ply < 2))
+ {
+ pv.push_back(m);
+ pos.do_move(m, *st++);
+ ply++;
}
+ pv.push_back(MOVE_NONE);
+ do pos.undo_move(pv[--ply]); while (ply);
+}
- // insert_pv_in_tt() is called at the end of a search iteration, and inserts
- // the PV back into the TT. This makes sure the old PV moves are searched
- // first, even if the old TT entries have been overwritten.
- void RootMove::insert_pv_in_tt(Position& pos) {
+/// RootMove::insert_pv_in_tt() is called at the end of a search iteration, and
+/// inserts the PV back into the TT. This makes sure the old PV moves are searched
+/// first, even if the old TT entries have been overwritten.
- StateInfo state[MAX_PLY_PLUS_2], *st = state;
- TTEntry* tte;
- Key k;
- Value v, m = VALUE_NONE;
- int ply = 0;
+void RootMove::insert_pv_in_tt(Position& pos) {
- assert(pv[ply] != MOVE_NONE && pos.is_pseudo_legal(pv[ply]));
+ StateInfo state[MAX_PLY_PLUS_2], *st = state;
+ TTEntry* tte;
+ Key k;
+ Value v, m = VALUE_NONE;
+ int ply = 0;
- do {
- k = pos.key();
- tte = TT.probe(k);
+ assert(pv[ply] != MOVE_NONE && pos.is_pseudo_legal(pv[ply]));
- // Don't overwrite existing correct entries
- if (!tte || tte->move() != pv[ply])
- {
- v = (pos.in_check() ? VALUE_NONE : evaluate(pos, m));
- TT.store(k, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[ply], v, m);
- }
- pos.do_move(pv[ply], *st++);
+ do {
+ k = pos.key();
+ tte = TT.probe(k);
- } while (pv[++ply] != MOVE_NONE);
+ // Don't overwrite existing correct entries
+ if (!tte || tte->move() != pv[ply])
+ {
+ v = (pos.in_check() ? VALUE_NONE : evaluate(pos, m));
+ TT.store(k, VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], v, m);
+ }
+ pos.do_move(pv[ply], *st++);
- do pos.undo_move(pv[--ply]); while (ply);
- }
+ } while (pv[++ply] != MOVE_NONE);
-} // namespace
+ do pos.undo_move(pv[--ply]); while (ply);
+}
/// 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.
+/// The parameter 'master_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) {
+void Thread::idle_loop(SplitPoint* sp_master) {
- while (true)
+ // If this thread is the master of a split point and all slaves have
+ // finished their work at this split point, return from the idle loop.
+ while (!sp_master || sp_master->slavesMask)
{
// If we are not searching, wait for a condition to be signaled
// instead of wasting CPU time polling for work.
while ( do_sleep
- || do_terminate
- || (Threads.use_sleeping_threads() && !is_searching))
+ || do_exit
+ || (!is_searching && Threads.use_sleeping_threads()))
{
- assert((!sp && threadID) || Threads.use_sleeping_threads());
-
- if (do_terminate)
+ if (do_exit)
{
- assert(!sp);
+ assert(!sp_master);
return;
}
// Grab the lock to avoid races with Thread::wake_up()
- lock_grab(&sleepLock);
+ lock_grab(sleepLock);
// If we are master and all slaves have finished don't go to sleep
- if (sp && Threads.split_point_finished(sp))
+ if (sp_master && !sp_master->slavesMask)
{
- lock_release(&sleepLock);
+ lock_release(sleepLock);
break;
}
// in the meanwhile, allocated us and sent the wake_up() call before we
// had the chance to grab the lock.
if (do_sleep || !is_searching)
- cond_wait(&sleepCond, &sleepLock);
+ cond_wait(sleepCond, sleepLock);
- lock_release(&sleepLock);
+ lock_release(sleepLock);
}
// If this thread has been assigned work, launch a search
if (is_searching)
{
- assert(!do_terminate);
+ assert(!do_sleep && !do_exit);
+
+ lock_grab(Threads.splitLock);
+
+ assert(is_searching);
+ SplitPoint* sp = curSplitPoint;
+
+ lock_release(Threads.splitLock);
- // Copy split point position and search stack and call search()
Stack ss[MAX_PLY_PLUS_2];
- SplitPoint* tsp = splitPoint;
- Position pos(*tsp->pos, threadID);
-
- memcpy(ss, tsp->ss - 1, 4 * sizeof(Stack));
- (ss+1)->sp = tsp;
-
- if (tsp->nodeType == Root)
- search<SplitPointRoot>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
- else if (tsp->nodeType == PV)
- search<SplitPointPV>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
- else if (tsp->nodeType == NonPV)
- search<SplitPointNonPV>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
+ Position pos(*sp->pos, threadID);
+ int master = sp->master;
+
+ memcpy(ss, sp->ss - 1, 4 * sizeof(Stack));
+ (ss+1)->sp = sp;
+
+ lock_grab(sp->lock);
+
+ if (sp->nodeType == Root)
+ search<SplitPointRoot>(pos, ss+1, sp->alpha, sp->beta, sp->depth);
+ else if (sp->nodeType == PV)
+ search<SplitPointPV>(pos, ss+1, sp->alpha, sp->beta, sp->depth);
+ else if (sp->nodeType == NonPV)
+ search<SplitPointNonPV>(pos, ss+1, sp->alpha, sp->beta, sp->depth);
else
assert(false);
assert(is_searching);
is_searching = false;
+ sp->slavesMask &= ~(1ULL << threadID);
+ sp->nodes += pos.nodes_searched();
+
+ // After releasing the lock we cannot access anymore any SplitPoint
+ // related data in a reliably way becuase it could have been released
+ // under our feet by the sp master.
+ lock_release(sp->lock);
// Wake up master thread so to allow it to return from the idle loop in
// case we are the last slave of the split point.
if ( Threads.use_sleeping_threads()
- && threadID != tsp->master
- && !Threads[tsp->master].is_searching)
- Threads[tsp->master].wake_up();
- }
-
- // If this thread is the master of a split point and all slaves have
- // finished their work at this split point, return from the idle loop.
- if (sp && Threads.split_point_finished(sp))
- {
- // Because sp->is_slave[] is reset under lock protection,
- // be sure sp->lock has been released before to return.
- lock_grab(&(sp->lock));
- lock_release(&(sp->lock));
- return;
+ && threadID != master
+ && !Threads[master].is_searching)
+ Threads[master].wake_up();
}
}
}
-/// do_timer_event() 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
+/// 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_timer_event() {
+void check_time() {
- static int lastInfoTime;
- int e = elapsed_time();
+ static Time lastInfoTime = Time::current_time();
- if (system_time() - lastInfoTime >= 1000 || !lastInfoTime)
+ if (lastInfoTime.elapsed() >= 1000)
{
- lastInfoTime = system_time();
+ lastInfoTime.restart();
dbg_print();
}
if (Limits.ponder)
return;
+ int e = SearchTime.elapsed();
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)
- || (Limits.maxTime && e >= Limits.maxTime)
- /* missing nodes limit */ ) // FIXME
+ if ( (Limits.use_time_management() && noMoreTime)
+ || (Limits.movetime && e >= Limits.movetime))
Signals.stop = true;
}
projects / stockfish / blobdiff