X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=0b4125fcdd6ccf05279c848c1257eed89c042343;hp=f0ee1b2b90f628c389627c29a989c98936017322;hb=8e45e70e55c42c4750ccb729dcd49cdaafe5af44;hpb=5f096e9bef7dd2fa5506066f38a477944aa715cc diff --git a/src/search.cpp b/src/search.cpp index f0ee1b2b..0b4125fc 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -261,19 +261,6 @@ void MainThread::search() { DrawValue[ us] = VALUE_DRAW - Value(contempt); DrawValue[~us] = VALUE_DRAW + Value(contempt); - TB::Hits = 0; - TB::RootInTB = false; - TB::UseRule50 = Options["Syzygy50MoveRule"]; - TB::ProbeDepth = Options["SyzygyProbeDepth"] * ONE_PLY; - TB::Cardinality = Options["SyzygyProbeLimit"]; - - // Skip TB probing when no TB found: !TBLargest -> !TB::Cardinality - if (TB::Cardinality > TB::MaxCardinality) - { - TB::Cardinality = TB::MaxCardinality; - TB::ProbeDepth = DEPTH_ZERO; - } - if (rootMoves.empty()) { rootMoves.push_back(RootMove(MOVE_NONE)); @@ -283,38 +270,6 @@ void MainThread::search() { } else { - if ( TB::Cardinality >= rootPos.count(WHITE) - + rootPos.count(BLACK) - && !rootPos.can_castle(ANY_CASTLING)) - { - // If the current root position is in the tablebases, then RootMoves - // contains only moves that preserve the draw or the win. - TB::RootInTB = Tablebases::root_probe(rootPos, rootMoves, TB::Score); - - if (TB::RootInTB) - TB::Cardinality = 0; // Do not probe tablebases during the search - - else // If DTZ tables are missing, use WDL tables as a fallback - { - // Filter out moves that do not preserve the draw or the win. - TB::RootInTB = Tablebases::root_probe_wdl(rootPos, rootMoves, TB::Score); - - // Only probe during search if winning - if (TB::Score <= VALUE_DRAW) - TB::Cardinality = 0; - } - - if (TB::RootInTB) - { - TB::Hits = rootMoves.size(); - - if (!TB::UseRule50) - TB::Score = TB::Score > VALUE_DRAW ? VALUE_MATE - MAX_PLY - 1 - : TB::Score < VALUE_DRAW ? -VALUE_MATE + MAX_PLY + 1 - : VALUE_DRAW; - } - } - for (Thread* th : Threads) if (th != this) th->start_searching(); @@ -458,11 +413,6 @@ void Thread::search() { // search the already searched PV lines are preserved. std::stable_sort(rootMoves.begin() + PVIdx, rootMoves.end()); - // Write PV back to the transposition table in case the relevant - // entries have been overwritten during the search. - for (size_t i = 0; i <= PVIdx; ++i) - rootMoves[i].insert_pv_in_tt(rootPos); - // If search has been stopped, break immediately. Sorting and // writing PV back to TT is safe because RootMoves is still // valid, although it refers to the previous iteration. @@ -608,7 +558,7 @@ namespace { Depth extension, newDepth, predictedDepth; Value bestValue, value, ttValue, eval, nullValue; bool ttHit, inCheck, givesCheck, singularExtensionNode, improving; - bool captureOrPromotion, doFullDepthSearch; + bool captureOrPromotion, doFullDepthSearch, moveCountPruning; Piece moved_piece; int moveCount, quietCount; @@ -919,8 +869,13 @@ moves_loop: // When in check search starts from here ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) : pos.gives_check(move, ci); + moveCountPruning = depth < 16 * ONE_PLY + && moveCount >= FutilityMoveCounts[improving][depth]; + // Step 12. Extend checks - if (givesCheck && pos.see_sign(move) >= VALUE_ZERO) + if ( givesCheck + && ( moveCount == 1 + || (!moveCountPruning && pos.see_sign(move) >= VALUE_ZERO))) extension = ONE_PLY; // Singular extension search. If all moves but one fail low on a search of @@ -956,8 +911,7 @@ moves_loop: // When in check search starts from here && bestValue > VALUE_MATED_IN_MAX_PLY) { // Move count based pruning - if ( depth < 16 * ONE_PLY - && moveCount >= FutilityMoveCounts[improving][depth]) + if (moveCountPruning) continue; // Countermoves based pruning @@ -1010,7 +964,7 @@ moves_loop: // When in check search starts from here // Increase reduction for cut nodes if (!PvNode && cutNode) - r += ONE_PLY; + 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 @@ -1019,7 +973,7 @@ moves_loop: // When in check search starts from here 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 -= ONE_PLY; + r -= 2 * ONE_PLY; // Decrease/increase reduction for moves with a good/bad history int rHist = (val - 10000) / 20000; @@ -1155,7 +1109,7 @@ moves_loop: // When in check search starts from here && !pos.captured_piece_type() && is_ok((ss-1)->currentMove)) { - Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1); + 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); @@ -1435,7 +1389,7 @@ moves_loop: // When in check search starts from here ss->killers[0] = move; } - Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1); + 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; @@ -1476,13 +1430,13 @@ moves_loop: // When in check search starts from here 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); + (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); + (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); + (ss-5)->counterMoves->update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY - 1); } } @@ -1605,33 +1559,6 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { } -/// 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. - -void RootMove::insert_pv_in_tt(Position& pos) { - - StateInfo state[MAX_PLY], *st = state; - bool ttHit; - - for (Move m : pv) - { - assert(MoveList(pos).contains(m)); - - TTEntry* tte = TT.probe(pos.key(), ttHit); - - if (!ttHit || tte->move() != m) // Don't overwrite correct entries - tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, - m, VALUE_NONE, TT.generation()); - - pos.do_move(m, *st++, pos.gives_check(m, CheckInfo(pos))); - } - - for (size_t i = pv.size(); i > 0; ) - pos.undo_move(pv[--i]); -} - - /// RootMove::extract_ponder_from_tt() is called in case we have no ponder move /// before exiting the search, for instance, in case we stop the search during a /// fail high at root. We try hard to have a ponder move to return to the GUI, @@ -1657,3 +1584,49 @@ bool RootMove::extract_ponder_from_tt(Position& pos) return false; } + +void Tablebases::filter_root_moves(Position& pos, Search::RootMoves& rootMoves) { + + Hits = 0; + RootInTB = false; + UseRule50 = Options["Syzygy50MoveRule"]; + ProbeDepth = Options["SyzygyProbeDepth"] * ONE_PLY; + Cardinality = Options["SyzygyProbeLimit"]; + + // Skip TB probing when no TB found: !TBLargest -> !TB::Cardinality + if (Cardinality > MaxCardinality) + { + Cardinality = MaxCardinality; + ProbeDepth = DEPTH_ZERO; + } + + if (Cardinality < popcount(pos.pieces()) || pos.can_castle(ANY_CASTLING)) + return; + + // If the current root position is in the tablebases, then RootMoves + // contains only moves that preserve the draw or the win. + RootInTB = root_probe(pos, rootMoves, TB::Score); + + if (RootInTB) + Cardinality = 0; // Do not probe tablebases during the search + + else // If DTZ tables are missing, use WDL tables as a fallback + { + // Filter out moves that do not preserve the draw or the win. + RootInTB = root_probe_wdl(pos, rootMoves, TB::Score); + + // Only probe during search if winning + if (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; + } +}