X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=81b3f29f335119e4aa7945f689fb68205dca7279;hp=fe450a4e9adc2956128e1dd787c319dcc06b9dff;hb=e27d3bb884dc17027010c1ea8f7e7d9efb383d4c;hpb=c5828c4eba9e4e3f448e8370f24804da719a5120 diff --git a/src/search.cpp b/src/search.cpp index fe450a4e..81b3f29f 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" @@ -157,7 +158,6 @@ namespace { EasyMoveManager EasyMove; Value DrawValue[COLOR_NB]; - CounterMoveHistoryStats CounterMoveHistory; template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode); @@ -208,13 +208,13 @@ 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(); } Threads.main()->previousScore = VALUE_INFINITE; @@ -506,7 +506,7 @@ 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". @@ -560,7 +560,7 @@ namespace { 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; @@ -650,7 +650,7 @@ namespace { } // 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-1)->moveCount == 1 && !pos.captured_piece()) { Value penalty = Value(d * d + 4 * d + 1); Square prevSq = to_sq((ss-1)->currentMove); @@ -728,8 +728,7 @@ namespace { && 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 / ONE_PLY]; @@ -744,7 +743,7 @@ 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 @@ -807,7 +806,7 @@ namespace { if (pos.legal(move)) { ss->currentMove = move; - ss->counterMoves = &CounterMoveHistory[pos.moved_piece(move)][to_sq(move)]; + ss->counterMoves = &thisThread->counterMoveHistory[pos.moved_piece(move)][to_sq(move)]; pos.do_move(move, st, pos.gives_check(move)); value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode); pos.undo_move(move); @@ -845,8 +844,7 @@ 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; @@ -891,7 +889,7 @@ moves_loop: // When in check search starts from here // 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 @@ -904,7 +902,7 @@ moves_loop: // When in check search starts from here && !extension && 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; @@ -920,41 +918,42 @@ 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 - && bestValue > VALUE_MATED_IN_MAX_PLY - && !pos.advanced_pawn_push(move)) + if ( !rootNode + && bestValue > VALUE_MATED_IN_MAX_PLY) { - // Move count based pruning - if (moveCountPruning) - continue; - - predictedDepth = std::max(newDepth - reduction(improving, depth, moveCount), DEPTH_ZERO); + if ( !captureOrPromotion + && !givesCheck + && !pos.advanced_pawn_push(move)) + { + // Move count based pruning + if (moveCountPruning) + continue; - // Countermoves based pruning - if ( predictedDepth < 3 * ONE_PLY - && (!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; - // Futility pruning: parent node - if ( predictedDepth < 7 * ONE_PLY - && ss->staticEval + 256 + 200 * predictedDepth / ONE_PLY <= alpha) - continue; + // 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; - // Prune moves with negative SEE at low depths and below a decreasing - // threshold at higher depths. - if (predictedDepth < 8 * ONE_PLY) - { - Value see_v = predictedDepth < 4 * ONE_PLY ? VALUE_ZERO - : -PawnValueMg * 2 * int(predictedDepth - 3 * ONE_PLY) / ONE_PLY; + // Futility pruning: parent node + if ( lmrDepth < 7 + && !inCheck + && ss->staticEval + 256 + 200 * lmrDepth <= alpha) + continue; - if (pos.see_sign(move) < see_v) + // Prune moves with negative SEE + if ( lmrDepth < 8 + && !pos.see_ge(move, Value(-35 * lmrDepth * lmrDepth))) continue; } + else if ( depth < 7 * ONE_PLY + && !extension + && !pos.see_ge(move, Value(-35 * depth / ONE_PLY * depth / ONE_PLY))) + continue; } // Speculative prefetch as early as possible @@ -968,7 +967,7 @@ moves_loop: // When in check search starts from here } 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); @@ -995,7 +994,7 @@ moves_loop: // When in check search starts from here // 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) + && !pos.see_ge(make_move(to_sq(move), from_sq(move)), VALUE_ZERO)) r -= 2 * ONE_PLY; // Decrease/increase reduction for moves with a good/bad history @@ -1123,6 +1122,9 @@ 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()]; @@ -1138,7 +1140,7 @@ moves_loop: // When in check search starts from here } // 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-1)->moveCount == 1 && !pos.captured_piece()) { Value penalty = Value(d * d + 4 * d + 1); Square prevSq = to_sq((ss-1)->currentMove); @@ -1147,7 +1149,7 @@ moves_loop: // When in check search starts from here } // Bonus for prior countermove that caused the fail low else if ( depth >= 3 * ONE_PLY - && !pos.captured_piece_type() + && !pos.captured_piece() && is_ok((ss-1)->currentMove)) { int d = depth / ONE_PLY; @@ -1302,7 +1304,7 @@ 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; @@ -1317,7 +1319,7 @@ 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 @@ -1589,13 +1591,16 @@ 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); + if (!pv[0]) + return false; + pos.do_move(pv[0], st, pos.gives_check(pv[0])); TTEntry* tte = TT.probe(pos.key(), ttHit);