X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=37a962663fd241434642d09c89c760682483a8b1;hp=1d40f8a070bfbe9f64ccd85355985aa54a769916;hb=69ac45d903a809bb80cabf87181958e1311c3fcc;hpb=7e3dba4f4ca6166068946552ec5720a179175f62 diff --git a/src/search.cpp b/src/search.cpp index 1d40f8a0..37a96266 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -25,11 +25,11 @@ #include #include -#include "book.h" #include "evaluate.h" #include "movegen.h" #include "movepick.h" #include "notation.h" +#include "rkiss.h" #include "search.h" #include "timeman.h" #include "thread.h" @@ -42,7 +42,6 @@ namespace Search { LimitsType Limits; std::vector RootMoves; Position RootPos; - Color RootColor; Time::point SearchTime; StateStackPtr SetupStates; } @@ -77,6 +76,9 @@ namespace { return (Depth) Reductions[PvNode][i][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)]; } + // Tempo bonus. Must be handled by search to preserve eval symmetry. + const int Tempo = 17; + size_t MultiPV, PVIdx; TimeManager TimeMgr; double BestMoveChanges; @@ -94,7 +96,7 @@ namespace { void id_loop(Position& pos); Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); - void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt); + void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt); string uci_pv(const Position& pos, int depth, Value alpha, Value beta); struct Skill { @@ -180,14 +182,11 @@ uint64_t Search::perft(Position& pos, Depth depth) { void Search::think() { - static PolyglotBook book; // Defined static to initialize the PRNG only once - - RootColor = RootPos.side_to_move(); - TimeMgr.init(Limits, RootPos.game_ply(), RootColor); + TimeMgr.init(Limits, RootPos.game_ply(), RootPos.side_to_move()); int cf = Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns - DrawValue[ RootColor] = VALUE_DRAW - Value(cf); - DrawValue[~RootColor] = VALUE_DRAW + Value(cf); + DrawValue[ RootPos.side_to_move()] = VALUE_DRAW - Value(cf); + DrawValue[~RootPos.side_to_move()] = VALUE_DRAW + Value(cf); if (RootMoves.empty()) { @@ -199,25 +198,14 @@ void Search::think() { goto finalize; } - if (Options["OwnBook"] && !Limits.infinite && !Limits.mate) - { - Move bookMove = book.probe(RootPos, Options["Book File"], Options["Best Book Move"]); - - if (bookMove && std::count(RootMoves.begin(), RootMoves.end(), bookMove)) - { - std::swap(RootMoves[0], *std::find(RootMoves.begin(), RootMoves.end(), bookMove)); - goto finalize; - } - } - if (Options["Write Search Log"]) { Log log(Options["Search Log Filename"]); log << "\nSearching: " << RootPos.fen() << "\ninfinite: " << Limits.infinite << " ponder: " << Limits.ponder - << " time: " << Limits.time[RootColor] - << " increment: " << Limits.inc[RootColor] + << " time: " << Limits.time[RootPos.side_to_move()] + << " increment: " << Limits.inc[RootPos.side_to_move()] << " moves to go: " << Limits.movestogo << "\n" << std::endl; } @@ -226,14 +214,12 @@ void Search::think() { for (size_t i = 0; i < Threads.size(); ++i) Threads[i]->maxPly = 0; - Threads.sleepWhileIdle = Options["Idle Threads Sleep"]; Threads.timer->run = true; Threads.timer->notify_one(); // Wake up the recurring timer id_loop(RootPos); // Let's start searching ! Threads.timer->run = false; // Stop the timer - Threads.sleepWhileIdle = true; // Send idle threads to sleep if (Options["Write Search Log"]) { @@ -487,7 +473,7 @@ namespace { bestValue = -VALUE_INFINITE; ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; ss->ply = (ss-1)->ply + 1; - (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; + (ss+1)->skipNullMove = (ss+1)->nullChild = false; (ss+1)->reduction = DEPTH_ZERO; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; // Used to send selDepth info to GUI @@ -498,7 +484,7 @@ namespace { { // Step 2. Check for aborted search and immediate draw if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) - return ss->ply > MAX_PLY && !inCheck ? evaluate(pos) : DrawValue[pos.side_to_move()]; + return ss->ply > MAX_PLY && !inCheck ? evaluate(pos) + Tempo : DrawValue[pos.side_to_move()]; // 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 @@ -553,7 +539,7 @@ namespace { { // Never assume anything on values stored in TT if ((ss->staticEval = eval = tte->eval_value()) == VALUE_NONE) - eval = ss->staticEval = evaluate(pos); + eval = ss->staticEval = evaluate(pos) + Tempo; // Can ttValue be used as a better position evaluation? if (ttValue != VALUE_NONE) @@ -562,7 +548,7 @@ namespace { } else { - eval = ss->staticEval = evaluate(pos); + eval = ss->staticEval = ss->nullChild ? -(ss-1)->staticEval + 2 * Tempo : evaluate(pos) + Tempo; TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval); } @@ -584,6 +570,10 @@ namespace { && abs(beta) < VALUE_MATE_IN_MAX_PLY && !pos.pawn_on_7th(pos.side_to_move())) { + if ( depth <= ONE_PLY + && eval + razor_margin(3 * ONE_PLY) <= alpha) + return qsearch(pos, ss, alpha, beta, DEPTH_ZERO); + Value ralpha = alpha - razor_margin(depth); Value v = qsearch(pos, ss, ralpha, ralpha+1, DEPTH_ZERO); if (v <= ralpha) @@ -618,10 +608,10 @@ namespace { + int(eval - beta) / PawnValueMg * ONE_PLY; pos.do_null_move(st); - (ss+1)->skipNullMove = true; + (ss+1)->skipNullMove = (ss+1)->nullChild = true; nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1, DEPTH_ZERO) : - search(pos, ss+1, -beta, -beta+1, depth-R, !cutNode); - (ss+1)->skipNullMove = false; + (ss+1)->skipNullMove = (ss+1)->nullChild = false; pos.undo_null_move(); if (nullValue >= beta) @@ -879,13 +869,20 @@ moves_loop: // When in check and at SpNode search starts from here if (move == countermoves[0] || move == countermoves[1]) ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); + // Decrease reduction for moves that escape a capture + if ( ss->reduction + && type_of(move) == NORMAL + && type_of(pos.piece_on(to_sq(move))) != PAWN + && pos.see(make_move(to_sq(move), from_sq(move))) < 0) + ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); + Depth d = std::max(newDepth - ss->reduction, ONE_PLY); if (SpNode) alpha = splitPoint->alpha; value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); - // Research at intermediate depth if reduction is very high + // Re-search at intermediate depth if reduction is very high if (value > alpha && ss->reduction >= 4 * ONE_PLY) { Depth d2 = std::max(newDepth - 2 * ONE_PLY, ONE_PLY); @@ -1019,18 +1016,18 @@ moves_loop: // When in check and at SpNode search starts from here // must be mate or stalemate. If we are in a singular extension search then // return a fail low score. if (!moveCount) - return excludedMove ? alpha - : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; + bestValue = excludedMove ? alpha + : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; + + // Quiet best move: update killers, history, countermoves and followupmoves + else if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck) + update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1); TT.store(posKey, value_to_tt(bestValue, ss->ply), bestValue >= beta ? BOUND_LOWER : PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, depth, bestMove, ss->staticEval); - // Quiet best move: update killers, history, countermoves and followupmoves - if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck) - update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1); - assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); return bestValue; @@ -1069,7 +1066,7 @@ moves_loop: // When in check and at SpNode search starts from here // Check for an instant draw or if the maximum ply has been reached if (pos.is_draw() || ss->ply > MAX_PLY) - return ss->ply > MAX_PLY && !InCheck ? evaluate(pos) : DrawValue[pos.side_to_move()]; + return ss->ply > MAX_PLY && !InCheck ? evaluate(pos) + Tempo : DrawValue[pos.side_to_move()]; // Decide whether or not to include checks: this fixes also the type of // TT entry depth that we are going to use. Note that in qsearch we use @@ -1106,7 +1103,7 @@ moves_loop: // When in check and at SpNode search starts from here { // Never assume anything on values stored in TT if ((ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE) - ss->staticEval = bestValue = evaluate(pos); + ss->staticEval = bestValue = evaluate(pos) + Tempo; // Can ttValue be used as a better position evaluation? if (ttValue != VALUE_NONE) @@ -1114,7 +1111,7 @@ moves_loop: // When in check and at SpNode search starts from here bestValue = ttValue; } else - ss->staticEval = bestValue = evaluate(pos); + ss->staticEval = bestValue = ss->nullChild ? -(ss-1)->staticEval + 2 * Tempo : evaluate(pos) + Tempo; // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) @@ -1267,7 +1264,7 @@ moves_loop: // When in check and at SpNode search starts from here // update_stats() updates killers, history, countermoves and followupmoves stats after a fail-high // of a quiet move. - void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) { + void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) { if (ss->killers[0] != move) { @@ -1397,28 +1394,31 @@ void RootMove::extract_pv_from_tt(Position& pos) { StateInfo state[MAX_PLY_PLUS_6], *st = state; const TTEntry* tte; - int ply = 0; - Move m = pv[0]; + int ply = 1; // At root ply is 1... + Move m = pv[0]; // ...instead pv[] array starts from 0 + Value expectedScore = score; pv.clear(); do { pv.push_back(m); - assert(MoveList(pos).contains(pv[ply])); + assert(MoveList(pos).contains(pv[ply - 1])); - pos.do_move(pv[ply++], *st++); + pos.do_move(pv[ply++ - 1], *st++); tte = TT.probe(pos.key()); + expectedScore = -expectedScore; } while ( tte + && expectedScore == value_from_tt(tte->value(), ply) && pos.pseudo_legal(m = tte->move()) // Local copy, TT could change && pos.legal(m, pos.pinned_pieces(pos.side_to_move())) && ply < MAX_PLY - && (!pos.is_draw() || ply < 2)); + && (!pos.is_draw() || ply <= 2)); pv.push_back(MOVE_NONE); // Must be zero-terminating - while (ply) pos.undo_move(pv[--ply]); + while (--ply) pos.undo_move(pv[ply - 1]); } @@ -1430,21 +1430,21 @@ void RootMove::insert_pv_in_tt(Position& pos) { StateInfo state[MAX_PLY_PLUS_6], *st = state; const TTEntry* tte; - int ply = 0; + int idx = 0; // Ply starts from 1, we need to start from 0 do { tte = TT.probe(pos.key()); - if (!tte || tte->move() != pv[ply]) // Don't overwrite correct entries - TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], VALUE_NONE); + if (!tte || tte->move() != pv[idx]) // Don't overwrite correct entries + TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[idx], VALUE_NONE); - assert(MoveList(pos).contains(pv[ply])); + assert(MoveList(pos).contains(pv[idx])); - pos.do_move(pv[ply++], *st++); + pos.do_move(pv[idx++], *st++); - } while (pv[ply] != MOVE_NONE); + } while (pv[idx] != MOVE_NONE); - while (ply) pos.undo_move(pv[--ply]); + while (idx) pos.undo_move(pv[--idx]); } @@ -1462,7 +1462,7 @@ void Thread::idle_loop() { { // If we are not searching, wait for a condition to be signaled instead of // wasting CPU time polling for work. - while ((!searching && Threads.sleepWhileIdle) || exit) + while (!searching || exit) { if (exit) { @@ -1537,8 +1537,7 @@ void Thread::idle_loop() { // Wake up the 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.sleepWhileIdle - && this != sp->masterThread + if ( this != sp->masterThread && sp->slavesMask.none()) { assert(!sp->masterThread->searching); @@ -1547,8 +1546,7 @@ void Thread::idle_loop() { // After releasing the lock we can't access any SplitPoint related data // in a safe way because it could have been released under our feet by - // the sp master. Also accessing other Thread objects is unsafe because - // if we are exiting there is a chance that they are already freed. + // the sp master. sp->mutex.unlock(); // Try to late join to another split point if none of its slaves has @@ -1556,7 +1554,7 @@ void Thread::idle_loop() { if (Threads.size() > 2) for (size_t i = 0; i < Threads.size(); ++i) { - int size = Threads[i]->splitPointsSize; // Local copy + const int size = Threads[i]->splitPointsSize; // Local copy sp = size ? &Threads[i]->splitPoints[size - 1] : NULL; if ( sp