X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=2fa2ce7e27cb4e41c0243a8f55f987b3d8f2dd35;hp=a81c85273aa4e6325e103dcd1d7ec1afc2636054;hb=a47bbca0ea40ac007d64682c3ba51fa4158b2d3f;hpb=f2f3a06a1acfa14b3054bfd73d6c3966c326a7cc diff --git a/src/search.cpp b/src/search.cpp index a81c8527..2fa2ce7e 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -29,6 +29,7 @@ #include "misc.h" #include "movegen.h" #include "movepick.h" +#include "position.h" #include "search.h" #include "timeman.h" #include "thread.h" @@ -45,7 +46,6 @@ namespace Search { namespace Tablebases { int Cardinality; - uint64_t Hits; bool RootInTB; bool UseRule50; Depth ProbeDepth; @@ -65,14 +65,14 @@ namespace { // Razoring and futility margin based on depth const int razor_margin[4] = { 483, 570, 603, 554 }; - Value futility_margin(Depth d) { return Value(200 * d); } + Value futility_margin(Depth d) { return Value(150 * d / ONE_PLY); } // Futility and reductions lookup tables, initialized at startup - int FutilityMoveCounts[2][16]; // [improving][depth] - Depth Reductions[2][2][64][64]; // [pv][improving][depth][moveNumber] + int FutilityMoveCounts[2][16]; // [improving][depth] + int Reductions[2][2][64][64]; // [pv][improving][depth][moveNumber] template Depth reduction(bool i, Depth d, int mn) { - return Reductions[PvNode][i][std::min(d, 63 * ONE_PLY)][std::min(mn, 63)]; + return Reductions[PvNode][i][std::min(d / ONE_PLY, 63)][std::min(mn, 63)] * ONE_PLY; } // Skill structure is used to implement strength limit @@ -113,8 +113,8 @@ namespace { std::copy(newPv.begin(), newPv.begin() + 3, pv); StateInfo st[2]; - pos.do_move(newPv[0], st[0], pos.gives_check(newPv[0], CheckInfo(pos))); - pos.do_move(newPv[1], st[1], pos.gives_check(newPv[1], CheckInfo(pos))); + pos.do_move(newPv[0], st[0]); + pos.do_move(newPv[1], st[1]); expectedPosKey = pos.key(); pos.undo_move(newPv[1]); pos.undo_move(newPv[0]); @@ -153,11 +153,13 @@ namespace { {1, 0, 0, 0, 0, 1, 1 ,1}, }; + Value bonus(Depth depth) { int d = depth / ONE_PLY ; return Value(d * d + 2 * d - 2); } + Value penalty(Depth depth) { int d = depth / ONE_PLY ; return -Value(d * d + 4 * d + 1); } + const size_t HalfDensitySize = std::extent::value; EasyMoveManager EasyMove; Value DrawValue[COLOR_NB]; - CounterMoveHistoryStats CounterMoveHistory; template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode); @@ -168,7 +170,8 @@ namespace { Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); void update_pv(Move* pv, Move move, Move* childPv); - void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt); + void update_cm_stats(Stack* ss, Piece pc, Square s, Value bonus); + void update_stats(const Position& pos, Stack* ss, Move move, Move* quiets, int quietsCnt, Value bonus); void check_time(); } // namespace @@ -183,15 +186,13 @@ void Search::init() { for (int mc = 1; mc < 64; ++mc) { double r = log(d) * log(mc) / 2; - if (r < 0.80) - continue; - Reductions[NonPV][imp][d][mc] = int(std::round(r)) * ONE_PLY; - Reductions[PV][imp][d][mc] = std::max(Reductions[NonPV][imp][d][mc] - ONE_PLY, DEPTH_ZERO); + Reductions[NonPV][imp][d][mc] = int(std::round(r)); + Reductions[PV][imp][d][mc] = std::max(Reductions[NonPV][imp][d][mc] - 1, 0); // Increase reduction for non-PV nodes when eval is not improving - if (!imp && Reductions[NonPV][imp][d][mc] >= 2 * ONE_PLY) - Reductions[NonPV][imp][d][mc] += ONE_PLY; + if (!imp && Reductions[NonPV][imp][d][mc] >= 2) + Reductions[NonPV][imp][d][mc]++; } for (int d = 0; d < 16; ++d) @@ -207,12 +208,14 @@ void Search::init() { void Search::clear() { TT.clear(); - CounterMoveHistory.clear(); for (Thread* th : Threads) { th->history.clear(); th->counterMoves.clear(); + th->fromTo.clear(); + th->counterMoveHistory.clear(); + th->resetCalls = true; } Threads.main()->previousScore = VALUE_INFINITE; @@ -226,7 +229,6 @@ uint64_t Search::perft(Position& pos, Depth depth) { StateInfo st; uint64_t cnt, nodes = 0; - CheckInfo ci(pos); const bool leaf = (depth == 2 * ONE_PLY); for (const auto& m : MoveList(pos)) @@ -235,7 +237,7 @@ uint64_t Search::perft(Position& pos, Depth depth) { cnt = 1, nodes++; else { - pos.do_move(m, st, pos.gives_check(m, ci)); + pos.do_move(m, st); cnt = leaf ? MoveList(pos).size() : perft(pos, depth - ONE_PLY); nodes += cnt; pos.undo_move(m); @@ -336,12 +338,12 @@ void MainThread::search() { void Thread::search() { - Stack stack[MAX_PLY+7], *ss = stack+5; // To allow referencing (ss-5) and (ss+2) + Stack stack[MAX_PLY+7], *ss = stack+4; // To allow referencing (ss-4) and (ss+2) Value bestValue, alpha, beta, delta; Move easyMove = MOVE_NONE; MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr); - std::memset(ss-5, 0, 8 * sizeof(Stack)); + std::memset(ss-4, 0, 7 * sizeof(Stack)); bestValue = delta = alpha = -VALUE_INFINITE; beta = VALUE_INFINITE; @@ -366,15 +368,17 @@ void Thread::search() { multiPV = std::min(multiPV, rootMoves.size()); - // Iterative deepening loop until requested to stop or the target depth is reached. - while (++rootDepth < DEPTH_MAX && !Signals.stop && (!Limits.depth || Threads.main()->rootDepth <= Limits.depth)) + // Iterative deepening loop until requested to stop or the target depth is reached + while ( (rootDepth += ONE_PLY) < DEPTH_MAX + && !Signals.stop + && (!Limits.depth || Threads.main()->rootDepth / ONE_PLY <= Limits.depth)) { // Set up the new depths for the helper threads skipping on average every // 2nd ply (using a half-density matrix). if (!mainThread) { const Row& row = HalfDensity[(idx - 1) % HalfDensitySize]; - if (row[(rootDepth + rootPos.game_ply()) % row.size()]) + if (row[(rootDepth / ONE_PLY + rootPos.game_ply()) % row.size()]) continue; } @@ -459,11 +463,7 @@ void Thread::search() { if (!mainThread) continue; - if (Signals.stop) - sync_cout << "info nodes " << Threads.nodes_searched() - << " time " << Time.elapsed() << sync_endl; - - else if (PVIdx + 1 == multiPV || Time.elapsed() > 3000) + if (Signals.stop || PVIdx + 1 == multiPV || Time.elapsed() > 3000) sync_cout << UCI::pv(rootPos, rootDepth, alpha, beta) << sync_endl; } @@ -503,7 +503,7 @@ void Thread::search() { if ( rootMoves.size() == 1 || Time.elapsed() > Time.optimum() * unstablePvFactor * improvingFactor / 628 - || (mainThread->easyMovePlayed = doEasyMove)) + || (mainThread->easyMovePlayed = doEasyMove, doEasyMove)) { // If we are allowed to ponder do not stop the search now but // keep pondering until the GUI sends "ponderhit" or "stop". @@ -550,13 +550,14 @@ namespace { assert(PvNode || (alpha == beta - 1)); assert(DEPTH_ZERO < depth && depth < DEPTH_MAX); assert(!(PvNode && cutNode)); + assert(depth / ONE_PLY * ONE_PLY == depth); Move pv[MAX_PLY+1], quietsSearched[64]; StateInfo st; TTEntry* tte; Key posKey; Move ttMove, move, excludedMove, bestMove; - Depth extension, newDepth, predictedDepth; + Depth extension, newDepth; Value bestValue, value, ttValue, eval, nullValue; bool ttHit, inCheck, givesCheck, singularExtensionNode, improving; bool captureOrPromotion, doFullDepthSearch, moveCountPruning; @@ -567,6 +568,7 @@ namespace { Thread* thisThread = pos.this_thread(); inCheck = pos.checkers(); moveCount = quietCount = ss->moveCount = 0; + ss->history = VALUE_ZERO; bestValue = -VALUE_INFINITE; ss->ply = (ss-1)->ply + 1; @@ -574,9 +576,13 @@ namespace { if (thisThread->resetCalls.load(std::memory_order_relaxed)) { thisThread->resetCalls = false; - thisThread->callsCnt = 0; + // At low node count increase the checking rate to about 0.1% of nodes + // otherwise use a default value. + thisThread->callsCnt = Limits.nodes ? std::min((int64_t)4096, Limits.nodes / 1024) + : 4096; } - if (++thisThread->callsCnt > 4096) + + if (--thisThread->callsCnt <= 0) { for (Thread* th : Threads) th->resetCalls = true; @@ -613,12 +619,13 @@ namespace { ss->counterMoves = nullptr; (ss+1)->skipEarlyPruning = false; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; + Square prevSq = to_sq((ss-1)->currentMove); // Step 4. Transposition table lookup. 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.exclusion_key() : pos.key(); + posKey = pos.key() ^ Key(excludedMove); tte = TT.probe(posKey, ttHit); ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; ttMove = rootNode ? thisThread->rootMoves[thisThread->PVIdx].pv[0] @@ -632,12 +639,16 @@ namespace { && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) : (tte->bound() & BOUND_UPPER))) { - ss->currentMove = ttMove; // Can be MOVE_NONE - // If ttMove is quiet, update killers, history, counter move on TT hit - if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove)) - update_stats(pos, ss, ttMove, depth, nullptr, 0); + if (ttValue >= beta && ttMove) + { + if (!pos.capture_or_promotion(ttMove)) + update_stats(pos, ss, ttMove, nullptr, 0, bonus(depth)); + // Extra penalty for a quiet TT move in previous ply when it gets refuted + if ((ss-1)->moveCount == 1 && !pos.captured_piece()) + update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, penalty(depth)); + } return ttValue; } @@ -651,11 +662,12 @@ namespace { && pos.rule50_count() == 0 && !pos.can_castle(ANY_CASTLING)) { - int found, v = Tablebases::probe_wdl(pos, &found); + TB::ProbeState err; + TB::WDLScore v = Tablebases::probe_wdl(pos, &err); - if (found) + if (err != TB::ProbeState::FAIL) { - TB::Hits++; + thisThread->tbHits++; int drawScore = TB::UseRule50 ? 1 : 0; @@ -706,14 +718,13 @@ namespace { // Step 6. Razoring (skipped when in check) if ( !PvNode && depth < 4 * ONE_PLY - && eval + razor_margin[depth] <= alpha - && ttMove == MOVE_NONE) + && ttMove == MOVE_NONE + && eval + razor_margin[depth / ONE_PLY] <= alpha) { - if ( depth <= ONE_PLY - && eval + razor_margin[3 * ONE_PLY] <= alpha) + if (depth <= ONE_PLY) return qsearch(pos, ss, alpha, beta, DEPTH_ZERO); - Value ralpha = alpha - razor_margin[depth]; + Value ralpha = alpha - razor_margin[depth / ONE_PLY]; Value v = qsearch(pos, ss, ralpha, ralpha+1, DEPTH_ZERO); if (v <= ralpha) return v; @@ -725,7 +736,7 @@ namespace { && eval - futility_margin(depth) >= beta && eval < VALUE_KNOWN_WIN // Do not return unproven wins && pos.non_pawn_material(pos.side_to_move())) - return eval - futility_margin(depth); + return eval; // Step 8. Null move search with verification search (is omitted in PV nodes) if ( !PvNode @@ -739,7 +750,7 @@ namespace { assert(eval - beta >= 0); // Null move dynamic reduction based on depth and value - Depth R = ((823 + 67 * depth) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY; + Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY; pos.do_null_move(st); (ss+1)->skipEarlyPruning = true; @@ -769,9 +780,8 @@ namespace { } // Step 9. ProbCut (skipped when in check) - // If we have a very good capture (i.e. SEE > seeValues[captured_piece_type]) - // and a reduced search returns a value much above beta, we can (almost) - // safely prune the previous move. + // If we have a good enough capture and a reduced search returns a value + // much above beta, we can (almost) safely prune the previous move. if ( !PvNode && depth >= 5 * ONE_PLY && abs(beta) < VALUE_MATE_IN_MAX_PLY) @@ -783,15 +793,14 @@ namespace { assert((ss-1)->currentMove != MOVE_NONE); assert((ss-1)->currentMove != MOVE_NULL); - MovePicker mp(pos, ttMove, PieceValue[MG][pos.captured_piece_type()]); - CheckInfo ci(pos); + MovePicker mp(pos, ttMove, rbeta - ss->staticEval); while ((move = mp.next_move()) != MOVE_NONE) - if (pos.legal(move, ci.pinned)) + if (pos.legal(move)) { ss->currentMove = move; - ss->counterMoves = &CounterMoveHistory[pos.moved_piece(move)][to_sq(move)]; - pos.do_move(move, st, pos.gives_check(move, ci)); + ss->counterMoves = &thisThread->counterMoveHistory[pos.moved_piece(move)][to_sq(move)]; + pos.do_move(move, st); value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode); pos.undo_move(move); if (value >= rbeta) @@ -800,11 +809,11 @@ namespace { } // Step 10. Internal iterative deepening (skipped when in check) - if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY) + if ( depth >= 6 * ONE_PLY && !ttMove && (PvNode || ss->staticEval + 256 >= beta)) { - Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); + Depth d = (3 * depth / (4 * ONE_PLY) - 2) * ONE_PLY; ss->skipEarlyPruning = true; search(pos, ss, alpha, beta, d, cutNode); ss->skipEarlyPruning = false; @@ -820,7 +829,6 @@ moves_loop: // When in check search starts from here const CounterMoveStats* fmh2 = (ss-4)->counterMoves; MovePicker mp(pos, ttMove, depth, ss); - CheckInfo ci(pos); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc improving = ss->staticEval >= (ss-2)->staticEval /* || ss->staticEval == VALUE_NONE Already implicit in the previous condition */ @@ -829,8 +837,7 @@ moves_loop: // When in check search starts from here singularExtensionNode = !rootNode && depth >= 8 * ONE_PLY && ttMove != MOVE_NONE - /* && ttValue != VALUE_NONE Already implicit in the next condition */ - && abs(ttValue) < VALUE_KNOWN_WIN + && ttValue != VALUE_NONE && !excludedMove // Recursive singular search is not allowed && (tte->bound() & BOUND_LOWER) && tte->depth() >= depth - 3 * ONE_PLY; @@ -865,17 +872,17 @@ moves_loop: // When in check search starts from here captureOrPromotion = pos.capture_or_promotion(move); moved_piece = pos.moved_piece(move); - givesCheck = type_of(move) == NORMAL && !ci.dcCandidates - ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) - : pos.gives_check(move, ci); + givesCheck = type_of(move) == NORMAL && !pos.discovered_check_candidates() + ? pos.check_squares(type_of(pos.piece_on(from_sq(move)))) & to_sq(move) + : pos.gives_check(move); moveCountPruning = depth < 16 * ONE_PLY - && moveCount >= FutilityMoveCounts[improving][depth]; + && moveCount >= FutilityMoveCounts[improving][depth / ONE_PLY]; // Step 12. Extend checks if ( givesCheck && !moveCountPruning - && pos.see_sign(move) >= VALUE_ZERO) + && pos.see_ge(move, VALUE_ZERO)) extension = ONE_PLY; // Singular extension search. If all moves but one fail low on a search of @@ -886,12 +893,13 @@ moves_loop: // When in check search starts from here if ( singularExtensionNode && move == ttMove && !extension - && pos.legal(move, ci.pinned)) + && pos.legal(move)) { - Value rBeta = ttValue - 2 * depth / ONE_PLY; + Value rBeta = std::max(ttValue - 2 * depth / ONE_PLY, -VALUE_MATE); + Depth d = (depth / (2 * ONE_PLY)) * ONE_PLY; ss->excludedMove = move; ss->skipEarlyPruning = true; - value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode); + value = search(pos, ss, rBeta - 1, rBeta, d, cutNode); ss->skipEarlyPruning = false; ss->excludedMove = MOVE_NONE; @@ -903,40 +911,46 @@ moves_loop: // When in check search starts from here newDepth = depth - ONE_PLY + extension; // Step 13. Pruning at shallow depth - if ( !rootNode - && !captureOrPromotion - && !inCheck - && !givesCheck - && !pos.advanced_pawn_push(move) - && bestValue > VALUE_MATED_IN_MAX_PLY) + if ( !rootNode + && bestValue > VALUE_MATED_IN_MAX_PLY) { - // Move count based pruning - if (moveCountPruning) - continue; + if ( !captureOrPromotion + && !givesCheck + && !pos.advanced_pawn_push(move)) + { + // Move count based pruning + if (moveCountPruning) + continue; - // Countermoves based pruning - if ( depth <= 4 * ONE_PLY - && move != ss->killers[0] - && (!cmh || (*cmh )[moved_piece][to_sq(move)] < VALUE_ZERO) - && (!fmh || (*fmh )[moved_piece][to_sq(move)] < VALUE_ZERO) - && (!fmh2 || (*fmh2)[moved_piece][to_sq(move)] < VALUE_ZERO || (cmh && fmh))) - continue; + // Reduced depth of the next LMR search + int lmrDepth = std::max(newDepth - reduction(improving, depth, moveCount), DEPTH_ZERO) / ONE_PLY; - predictedDepth = std::max(newDepth - reduction(improving, depth, moveCount), DEPTH_ZERO); + // Countermoves based pruning + if ( lmrDepth < 3 + && (!cmh || (*cmh )[moved_piece][to_sq(move)] < VALUE_ZERO) + && (!fmh || (*fmh )[moved_piece][to_sq(move)] < VALUE_ZERO) + && (!fmh2 || (*fmh2)[moved_piece][to_sq(move)] < VALUE_ZERO || (cmh && fmh))) + continue; - // Futility pruning: parent node - if ( predictedDepth < 7 * ONE_PLY - && ss->staticEval + futility_margin(predictedDepth) + 256 <= alpha) - continue; + // Futility pruning: parent node + if ( lmrDepth < 7 + && !inCheck + && ss->staticEval + 256 + 200 * lmrDepth <= alpha) + continue; - // Prune moves with negative SEE at low depths and below a decreasing - // threshold at higher depths. - if (predictedDepth < 8 * ONE_PLY) + // Prune moves with negative SEE + if ( lmrDepth < 8 + && !pos.see_ge(move, Value(-35 * lmrDepth * lmrDepth))) + continue; + } + else if (depth < 7 * ONE_PLY && !extension) { - Value see_v = predictedDepth < 4 * ONE_PLY ? VALUE_ZERO - : -PawnValueMg * 2 * int(predictedDepth - 3 * ONE_PLY); + Value v = -Value(399 + 35 * depth / ONE_PLY * depth / ONE_PLY); + + if (PvNode) + v += beta - alpha - 1; - if (pos.see_sign(move) < see_v) + if (!pos.see_ge(move, v)) continue; } } @@ -945,14 +959,14 @@ moves_loop: // When in check search starts from here prefetch(TT.first_entry(pos.key_after(move))); // Check for legality just before making the move - if (!rootNode && !pos.legal(move, ci.pinned)) + if (!rootNode && !pos.legal(move)) { ss->moveCount = --moveCount; continue; } ss->currentMove = move; - ss->counterMoves = &CounterMoveHistory[moved_piece][to_sq(move)]; + ss->counterMoves = &thisThread->counterMoveHistory[moved_piece][to_sq(move)]; // Step 14. Make the move pos.do_move(move, st, givesCheck); @@ -961,36 +975,48 @@ moves_loop: // When in check search starts from here // re-searched at full depth. if ( depth >= 3 * ONE_PLY && moveCount > 1 - && !captureOrPromotion) + && (!captureOrPromotion || moveCountPruning)) { Depth r = reduction(improving, depth, moveCount); - Value val = thisThread->history[moved_piece][to_sq(move)] - + (cmh ? (*cmh )[moved_piece][to_sq(move)] : VALUE_ZERO) - + (fmh ? (*fmh )[moved_piece][to_sq(move)] : VALUE_ZERO) - + (fmh2 ? (*fmh2)[moved_piece][to_sq(move)] : VALUE_ZERO); - - // Increase reduction for cut nodes - if (cutNode) - r += 2 * ONE_PLY; - - // Decrease reduction for moves that escape a capture. Filter out - // castling moves, because they are coded as "king captures rook" and - // hence break make_move(). Also use see() instead of see_sign(), - // because the destination square is empty. - else if ( type_of(move) == NORMAL - && type_of(pos.piece_on(to_sq(move))) != PAWN - && pos.see(make_move(to_sq(move), from_sq(move))) < VALUE_ZERO) - r -= 2 * ONE_PLY; - - // Decrease/increase reduction for moves with a good/bad history - int rHist = (val - 10000) / 20000; - r = std::max(DEPTH_ZERO, r - rHist * ONE_PLY); + + if (captureOrPromotion) + r -= r ? ONE_PLY : DEPTH_ZERO; + else + { + // Increase reduction for cut nodes + if (cutNode) + r += 2 * ONE_PLY; + + // Decrease reduction for moves that escape a capture. Filter out + // castling moves, because they are coded as "king captures rook" and + // hence break make_move(). + else if ( type_of(move) == NORMAL + && !pos.see_ge(make_move(to_sq(move), from_sq(move)), VALUE_ZERO)) + r -= 2 * ONE_PLY; + + ss->history = thisThread->history[moved_piece][to_sq(move)] + + (cmh ? (*cmh )[moved_piece][to_sq(move)] : VALUE_ZERO) + + (fmh ? (*fmh )[moved_piece][to_sq(move)] : VALUE_ZERO) + + (fmh2 ? (*fmh2)[moved_piece][to_sq(move)] : VALUE_ZERO) + + thisThread->fromTo.get(~pos.side_to_move(), move) + - 8000; // Correction factor + + // Decrease/increase reduction by comparing opponent's stat score + if (ss->history > VALUE_ZERO && (ss-1)->history < VALUE_ZERO) + r -= ONE_PLY; + + else if (ss->history < VALUE_ZERO && (ss-1)->history > VALUE_ZERO) + r += ONE_PLY; + + // Decrease/increase reduction for moves with a good/bad history + r = std::max(DEPTH_ZERO, (r / ONE_PLY - ss->history / 20000) * ONE_PLY); + } Depth d = std::max(newDepth - r, ONE_PLY); value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); - doFullDepthSearch = (value > alpha && r != DEPTH_ZERO); + doFullDepthSearch = (value > alpha && d != newDepth); } else doFullDepthSearch = !PvNode || moveCount > 1; @@ -1101,31 +1127,28 @@ moves_loop: // When in check search starts from here // All legal moves have been searched and if there are no legal moves, it // must be a mate or a stalemate. If we are in a singular extension search then // return a fail low score. + + assert(moveCount || !inCheck || excludedMove || !MoveList(pos).size()); + if (!moveCount) bestValue = excludedMove ? alpha : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; + else if (bestMove) + { - // Quiet best move: update killers, history and countermoves - else if (bestMove && !pos.capture_or_promotion(bestMove)) - update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount); + // Quiet best move: update killers, history and countermoves + if (!pos.capture_or_promotion(bestMove)) + update_stats(pos, ss, bestMove, quietsSearched, quietCount, bonus(depth)); + // Extra penalty for a quiet TT move in previous ply when it gets refuted + if ((ss-1)->moveCount == 1 && !pos.captured_piece()) + update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, penalty(depth)); + } // Bonus for prior countermove that caused the fail low else if ( depth >= 3 * ONE_PLY - && !bestMove - && !pos.captured_piece_type() + && !pos.captured_piece() && is_ok((ss-1)->currentMove)) - { - Square prevSq = to_sq((ss-1)->currentMove); - Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + 2 * depth / ONE_PLY - 2); - if ((ss-2)->counterMoves) - (ss-2)->counterMoves->update(pos.piece_on(prevSq), prevSq, bonus); - - if ((ss-3)->counterMoves) - (ss-3)->counterMoves->update(pos.piece_on(prevSq), prevSq, bonus); - - if ((ss-5)->counterMoves) - (ss-5)->counterMoves->update(pos.piece_on(prevSq), prevSq, bonus); - } + update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, bonus(depth)); tte->save(posKey, value_to_tt(bestValue, ss->ply), bestValue >= beta ? BOUND_LOWER : @@ -1151,6 +1174,7 @@ moves_loop: // When in check search starts from here assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); assert(PvNode || (alpha == beta - 1)); assert(depth <= DEPTH_ZERO); + assert(depth / ONE_PLY * ONE_PLY == depth); Move pv[MAX_PLY+1]; StateInfo st; @@ -1196,10 +1220,7 @@ moves_loop: // When in check search starts from here && ttValue != VALUE_NONE // Only in case of TT access race && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) : (tte->bound() & BOUND_UPPER))) - { - ss->currentMove = ttMove; // Can be MOVE_NONE return ttValue; - } // Evaluate the position statically if (InCheck) @@ -1246,16 +1267,15 @@ moves_loop: // When in check search starts from here // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will // be generated. MovePicker mp(pos, ttMove, depth, to_sq((ss-1)->currentMove)); - CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs while ((move = mp.next_move()) != MOVE_NONE) { assert(is_ok(move)); - givesCheck = type_of(move) == NORMAL && !ci.dcCandidates - ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) - : pos.gives_check(move, ci); + givesCheck = type_of(move) == NORMAL && !pos.discovered_check_candidates() + ? pos.check_squares(type_of(pos.piece_on(from_sq(move)))) & to_sq(move) + : pos.gives_check(move); // Futility pruning if ( !InCheck @@ -1273,7 +1293,7 @@ moves_loop: // When in check search starts from here continue; } - if (futilityBase <= alpha && pos.see(move) <= VALUE_ZERO) + if (futilityBase <= alpha && !pos.see_ge(move, VALUE_ZERO + 1)) { bestValue = std::max(bestValue, futilityBase); continue; @@ -1288,14 +1308,14 @@ moves_loop: // When in check search starts from here // Don't search moves with negative SEE values if ( (!InCheck || evasionPrunable) && type_of(move) != PROMOTION - && pos.see_sign(move) < VALUE_ZERO) + && !pos.see_ge(move, VALUE_ZERO)) continue; // Speculative prefetch as early as possible prefetch(TT.first_entry(pos.key_after(move))); // Check for legality just before making the move - if (!pos.legal(move, ci.pinned)) + if (!pos.legal(move)) continue; ss->currentMove = move; @@ -1384,11 +1404,30 @@ moves_loop: // When in check search starts from here } + // update_cm_stats() updates countermove and follow-up move history + + void update_cm_stats(Stack* ss, Piece pc, Square s, Value bonus) { + + CounterMoveStats* cmh = (ss-1)->counterMoves; + CounterMoveStats* fmh1 = (ss-2)->counterMoves; + CounterMoveStats* fmh2 = (ss-4)->counterMoves; + + if (cmh) + cmh->update(pc, s, bonus); + + if (fmh1) + fmh1->update(pc, s, bonus); + + if (fmh2) + fmh2->update(pc, s, bonus); + } + + // update_stats() updates killers, history, countermove and countermove plus // follow-up move history when a new quiet best move is found. void update_stats(const Position& pos, Stack* ss, Move move, - Depth depth, Move* quiets, int quietsCnt) { + Move* quiets, int quietsCnt, Value bonus) { if (ss->killers[0] != move) { @@ -1396,54 +1435,24 @@ moves_loop: // When in check search starts from here ss->killers[0] = move; } - Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + 2 * depth / ONE_PLY - 2); - - Square prevSq = to_sq((ss-1)->currentMove); - CounterMoveStats* cmh = (ss-1)->counterMoves; - CounterMoveStats* fmh = (ss-2)->counterMoves; - CounterMoveStats* fmh2 = (ss-4)->counterMoves; + Color c = pos.side_to_move(); Thread* thisThread = pos.this_thread(); - + thisThread->fromTo.update(c, move, bonus); thisThread->history.update(pos.moved_piece(move), to_sq(move), bonus); + update_cm_stats(ss, pos.moved_piece(move), to_sq(move), bonus); - if (cmh) + if ((ss-1)->counterMoves) { + Square prevSq = to_sq((ss-1)->currentMove); thisThread->counterMoves.update(pos.piece_on(prevSq), prevSq, move); - cmh->update(pos.moved_piece(move), to_sq(move), bonus); } - if (fmh) - fmh->update(pos.moved_piece(move), to_sq(move), bonus); - - if (fmh2) - fmh2->update(pos.moved_piece(move), to_sq(move), bonus); - // Decrease all the other played quiet moves for (int i = 0; i < quietsCnt; ++i) { + thisThread->fromTo.update(c, quiets[i], -bonus); thisThread->history.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); - - if (cmh) - cmh->update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); - - if (fmh) - fmh->update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); - - if (fmh2) - fmh2->update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); - } - - // Extra penalty for a quiet TT move in previous ply when it gets refuted - if ((ss-1)->moveCount == 1 && !pos.captured_piece_type()) - { - if ((ss-2)->counterMoves) - (ss-2)->counterMoves->update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY - 1); - - if ((ss-3)->counterMoves) - (ss-3)->counterMoves->update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY - 1); - - if ((ss-5)->counterMoves) - (ss-5)->counterMoves->update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY - 1); + update_cm_stats(ss, pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); } } @@ -1504,7 +1513,7 @@ moves_loop: // When in check search starts from here if ( (Limits.use_time_management() && elapsed > Time.maximum() - 10) || (Limits.movetime && elapsed >= Limits.movetime) - || (Limits.nodes && Threads.nodes_searched() >= Limits.nodes)) + || (Limits.nodes && Threads.nodes_searched() >= (uint64_t)Limits.nodes)) Signals.stop = true; } @@ -1521,7 +1530,8 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { const RootMoves& rootMoves = pos.this_thread()->rootMoves; size_t PVIdx = pos.this_thread()->PVIdx; size_t multiPV = std::min((size_t)Options["MultiPV"], rootMoves.size()); - uint64_t nodes_searched = Threads.nodes_searched(); + uint64_t nodesSearched = Threads.nodes_searched(); + uint64_t tbHits = Threads.tb_hits() + (TB::RootInTB ? rootMoves.size() : 0); for (size_t i = 0; i < multiPV; ++i) { @@ -1548,13 +1558,13 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { if (!tb && i == PVIdx) ss << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : ""); - ss << " nodes " << nodes_searched - << " nps " << nodes_searched * 1000 / elapsed; + ss << " nodes " << nodesSearched + << " nps " << nodesSearched * 1000 / elapsed; if (elapsed > 1000) // Earlier makes little sense ss << " hashfull " << TT.hashfull(); - ss << " tbhits " << TB::Hits + ss << " tbhits " << tbHits << " time " << elapsed << " pv"; @@ -1571,14 +1581,17 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { /// fail high at root. We try hard to have a ponder move to return to the GUI, /// otherwise in case of 'ponder on' we have nothing to think on. -bool RootMove::extract_ponder_from_tt(Position& pos) -{ +bool RootMove::extract_ponder_from_tt(Position& pos) { + StateInfo st; bool ttHit; assert(pv.size() == 1); - pos.do_move(pv[0], st, pos.gives_check(pv[0], CheckInfo(pos))); + if (!pv[0]) + return false; + + pos.do_move(pv[0], st); TTEntry* tte = TT.probe(pos.key(), ttHit); if (ttHit) @@ -1594,7 +1607,6 @@ bool RootMove::extract_ponder_from_tt(Position& pos) void Tablebases::filter_root_moves(Position& pos, Search::RootMoves& rootMoves) { - Hits = 0; RootInTB = false; UseRule50 = Options["Syzygy50MoveRule"]; ProbeDepth = Options["SyzygyProbeDepth"] * ONE_PLY; @@ -1623,17 +1635,12 @@ void Tablebases::filter_root_moves(Position& pos, Search::RootMoves& rootMoves) RootInTB = root_probe_wdl(pos, rootMoves, TB::Score); // Only probe during search if winning - if (TB::Score <= VALUE_DRAW) + if (RootInTB && TB::Score <= VALUE_DRAW) Cardinality = 0; } - if (RootInTB) - { - Hits = rootMoves.size(); - - if (!UseRule50) - TB::Score = TB::Score > VALUE_DRAW ? VALUE_MATE - MAX_PLY - 1 - : TB::Score < VALUE_DRAW ? -VALUE_MATE + MAX_PLY + 1 - : VALUE_DRAW; - } + if (RootInTB && !UseRule50) + TB::Score = TB::Score > VALUE_DRAW ? VALUE_MATE - MAX_PLY - 1 + : TB::Score < VALUE_DRAW ? -VALUE_MATE + MAX_PLY + 1 + : VALUE_DRAW; }