X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=5ea00331b9bd85b012f66f473295c092e0808066;hp=9f2786230477737160147feba907bb5fed0ed02b;hb=ba1464751d1186f723a2d2a5d18c06ddfc9a4cb3;hpb=7ad59d9ac9cbeae8b95843a720a53c99bb1f0d3b diff --git a/src/search.cpp b/src/search.cpp index 9f278623..5ea00331 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -33,17 +33,30 @@ #include "thread.h" #include "tt.h" #include "uci.h" +#include "syzygy/tbprobe.h" namespace Search { volatile SignalsType Signals; LimitsType Limits; - std::vector RootMoves; + RootMoveVector RootMoves; Position RootPos; Time::point SearchTime; StateStackPtr SetupStates; } +namespace Tablebases { + + int Cardinality; + uint64_t Hits; + bool RootInTB; + bool UseRule50; + Depth ProbeDepth; + Value Score; +} + +namespace TB = Tablebases; + using std::string; using Eval::evaluate; using namespace Search; @@ -102,7 +115,7 @@ namespace { } size_t candidates_size() const { return candidates; } - bool time_to_pick(Depth depth) const { return depth == 1 + level; } + bool time_to_pick(Depth depth) const { return depth / ONE_PLY == 1 + level; } Move pick_move(); int level; @@ -186,6 +199,19 @@ void Search::think() { DrawValue[ RootPos.side_to_move()] = VALUE_DRAW - Value(cf); DrawValue[~RootPos.side_to_move()] = VALUE_DRAW + Value(cf); + 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(MOVE_NONE); @@ -195,6 +221,37 @@ void Search::think() { } else { + if (TB::Cardinality >= RootPos.count(WHITE) + + RootPos.count(BLACK)) + { + // If the current root position is in the tablebases then RootMoves + // contains only moves that preserve the draw or 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 a draw or 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 (size_t i = 0; i < Threads.size(); ++i) Threads[i]->maxPly = 0; @@ -217,9 +274,12 @@ void Search::think() { RootPos.this_thread()->wait_for(Signals.stop); } - sync_cout << "bestmove " << UCI::format_move(RootMoves[0].pv[0], RootPos.is_chess960()) - << " ponder " << UCI::format_move(RootMoves[0].pv[1], RootPos.is_chess960()) - << sync_endl; + sync_cout << "bestmove " << UCI::format_move(RootMoves[0].pv[0], RootPos.is_chess960()); + + if (RootMoves[0].pv.size() > 1) + std::cout << " ponder " << UCI::format_move(RootMoves[0].pv[1], RootPos.is_chess960()); + + std::cout << sync_endl; } @@ -483,6 +543,36 @@ namespace { return ttValue; } + // Step 4a. Tablebase probe + if (!RootNode && TB::Cardinality) + { + int piecesCnt = pos.count(WHITE) + pos.count(BLACK); + + if ( piecesCnt <= TB::Cardinality + && (piecesCnt < TB::Cardinality || depth >= TB::ProbeDepth) + && pos.rule50_count() == 0) + { + int found, v = Tablebases::probe_wdl(pos, &found); + + if (found) + { + TB::Hits++; + + int drawScore = TB::UseRule50 ? 1 : 0; + + value = v < -drawScore ? -VALUE_MATE + MAX_PLY + ss->ply + : v > drawScore ? VALUE_MATE - MAX_PLY - ss->ply + : VALUE_DRAW + 2 * v * drawScore; + + TT.store(posKey, value_to_tt(value, ss->ply), BOUND_EXACT, + std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY), + MOVE_NONE, VALUE_NONE); + + return value; + } + } + } + // Step 5. Evaluate the position statically and update parent's gain statistics if (inCheck) { @@ -558,7 +648,7 @@ namespace { assert(eval - beta >= 0); // Null move dynamic reduction based on depth and value - Depth R = (3 + depth / 4 + std::min(int(eval - beta) / PawnValueMg, 3)) * ONE_PLY; + Depth R = (3 + depth / 4 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY; pos.do_null_move(st); (ss+1)->skipNullMove = true; @@ -691,7 +781,7 @@ moves_loop: // When in check and at SpNode search starts from here Signals.firstRootMove = (moveCount == 1); if (thisThread == Threads.main() && Time::now() - SearchTime > 3000) - sync_cout << "info depth " << depth + sync_cout << "info depth " << depth / ONE_PLY << " currmove " << UCI::format_move(move, pos.is_chess960()) << " currmovenumber " << moveCount + PVIdx << sync_endl; } @@ -724,7 +814,7 @@ moves_loop: // When in check and at SpNode search starts from here && !ext && pos.legal(move, ci.pinned)) { - Value rBeta = ttValue - int(2 * depth); + Value rBeta = ttValue - 2 * depth / ONE_PLY; ss->excludedMove = move; ss->skipNullMove = true; value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode); @@ -1260,7 +1350,7 @@ moves_loop: // When in check and at SpNode search starts from here // Increase history value of the cut-off move and decrease all the other // played quiet moves. - Value bonus = Value(int(depth) * int(depth)); + Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY)); History.update(pos.moved_piece(move), to_sq(move), bonus); for (int i = 0; i < quietsCnt; ++i) { @@ -1343,21 +1433,25 @@ moves_loop: // When in check and at SpNode search starts from here { bool updated = (i <= PVIdx); - if (depth == 1 && !updated) + if (depth == ONE_PLY && !updated) continue; Depth d = updated ? depth : depth - ONE_PLY; Value v = updated ? RootMoves[i].score : RootMoves[i].prevScore; + bool tb = TB::RootInTB && abs(v) < VALUE_MATE - MAX_PLY; + v = tb ? TB::Score : v; + if (ss.rdbuf()->in_avail()) // Not at first line ss << "\n"; ss << "info depth " << d / ONE_PLY << " seldepth " << selDepth << " multipv " << i + 1 - << " score " << (i == PVIdx ? UCI::format_value(v, alpha, beta) : UCI::format_value(v)) + << " score " << ((!tb && i == PVIdx) ? UCI::format_value(v, alpha, beta) : UCI::format_value(v)) << " nodes " << pos.nodes_searched() << " nps " << pos.nodes_searched() * 1000 / elapsed + << " tbhits " << TB::Hits << " time " << elapsed << " pv";