X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=da306a1a6150a487b3f6a734375e12023fd55862;hp=7cf4a8a3b583054b651d17b7c422564e859a7296;hb=44643c277007e3902586418541c0c22ff110fde1;hpb=158864270a055fe20dca4a87f4b7a8aa9cedfeb9 diff --git a/src/search.cpp b/src/search.cpp index 7cf4a8a3..da306a1a 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -20,14 +20,14 @@ #include #include #include -#include +#include // For std::memset #include #include #include "evaluate.h" +#include "misc.h" #include "movegen.h" #include "movepick.h" -#include "misc.h" #include "search.h" #include "timeman.h" #include "thread.h" @@ -179,7 +179,7 @@ uint64_t Search::perft(Position& pos, Depth depth) { pos.undo_move(*it); } if (Root) - sync_cout << UCI::format_move(*it, pos.is_chess960()) << ": " << cnt << sync_endl; + sync_cout << UCI::move(*it, pos.is_chess960()) << ": " << cnt << sync_endl; } return nodes; } @@ -193,7 +193,7 @@ template uint64_t Search::perft(Position& pos, Depth depth); void Search::think() { - TimeMgr.init(Limits, RootPos.game_ply(), RootPos.side_to_move()); + TimeMgr.init(Limits, RootPos.side_to_move(), RootPos.game_ply()); int contempt = Options["Contempt"] * PawnValueEg / 100; // From centipawns DrawValue[ RootPos.side_to_move()] = VALUE_DRAW - Value(contempt); @@ -216,7 +216,7 @@ void Search::think() { { RootMoves.push_back(MOVE_NONE); sync_cout << "info depth 0 score " - << UCI::format_value(RootPos.checkers() ? -VALUE_MATE : VALUE_DRAW) + << UCI::value(RootPos.checkers() ? -VALUE_MATE : VALUE_DRAW) << sync_endl; } else @@ -274,10 +274,10 @@ void Search::think() { RootPos.this_thread()->wait_for(Signals.stop); } - sync_cout << "bestmove " << UCI::format_move(RootMoves[0].pv[0], RootPos.is_chess960()); + sync_cout << "bestmove " << UCI::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()); + if (RootMoves[0].pv.size() > 1 || RootMoves[0].extract_ponder_from_tt(RootPos)) + std::cout << " ponder " << UCI::move(RootMoves[0].pv[1], RootPos.is_chess960()); std::cout << sync_endl; } @@ -365,7 +365,8 @@ namespace { // When failing high/low give some update (without cluttering // the UI) before a re-search. - if ( (bestValue <= alpha || bestValue >= beta) + if ( multiPV == 1 + && (bestValue <= alpha || bestValue >= beta) && Time::now() - SearchTime > 3000) sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl; @@ -457,13 +458,13 @@ namespace { Move pv[MAX_PLY+1], quietsSearched[64]; StateInfo st; - const TTEntry *tte; + TTEntry* tte; SplitPoint* splitPoint; Key posKey; Move ttMove, move, excludedMove, bestMove; Depth extension, newDepth, predictedDepth; Value bestValue, value, ttValue, eval, nullValue, futilityValue; - bool inCheck, givesCheck, singularExtensionNode, improving; + bool ttHit, inCheck, givesCheck, singularExtensionNode, improving; bool captureOrPromotion, dangerous, doFullDepthSearch; int moveCount, quietCount; @@ -477,6 +478,7 @@ namespace { bestMove = splitPoint->bestMove; bestValue = splitPoint->bestValue; tte = NULL; + ttHit = false; ttMove = excludedMove = MOVE_NONE; ttValue = VALUE_NONE; @@ -514,7 +516,7 @@ namespace { assert(0 <= ss->ply && ss->ply < MAX_PLY); ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; - (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; + (ss+1)->skipEarlyPruning = false; (ss+1)->reduction = DEPTH_ZERO; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; // Step 4. Transposition table lookup @@ -522,13 +524,13 @@ namespace { // 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(); - tte = TT.probe(posKey); - ss->ttMove = ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE; - ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; + tte = TT.probe(posKey, ttHit); + ss->ttMove = ttMove = RootNode ? RootMoves[PVIdx].pv[0] : ttHit ? tte->move() : MOVE_NONE; + ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; // At non-PV nodes we check for a fail high/low. We don't probe at PV nodes if ( !PvNode - && tte + && ttHit && tte->depth() >= depth && ttValue != VALUE_NONE // Only in case of TT access race && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) @@ -564,9 +566,9 @@ namespace { : 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); + tte->save(posKey, value_to_tt(value, ss->ply), BOUND_EXACT, + std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY), + MOVE_NONE, VALUE_NONE, TT.generation()); return value; } @@ -580,10 +582,10 @@ namespace { goto moves_loop; } - else if (tte) + else if (ttHit) { // Never assume anything on values stored in TT - if ((ss->staticEval = eval = tte->eval_value()) == VALUE_NONE) + if ((ss->staticEval = eval = tte->eval()) == VALUE_NONE) eval = ss->staticEval = evaluate(pos); // Can ttValue be used as a better position evaluation? @@ -596,9 +598,12 @@ namespace { eval = ss->staticEval = (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo; - TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval); + tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval, TT.generation()); } + if (ss->skipEarlyPruning) + goto moves_loop; + if ( !pos.captured_piece_type() && ss->staticEval != VALUE_NONE && (ss-1)->staticEval != VALUE_NONE @@ -628,8 +633,7 @@ namespace { } // Step 7. Futility pruning: child node (skipped when in check) - if ( !PvNode - && !ss->skipNullMove + if ( !RootNode && depth < 7 * ONE_PLY && eval - futility_margin(depth) >= beta && eval < VALUE_KNOWN_WIN // Do not return unproven wins @@ -638,7 +642,6 @@ namespace { // Step 8. Null move search with verification search (is omitted in PV nodes) if ( !PvNode - && !ss->skipNullMove && depth >= 2 * ONE_PLY && eval >= beta && pos.non_pawn_material(pos.side_to_move())) @@ -648,13 +651,13 @@ namespace { assert(eval - beta >= 0); // Null move dynamic reduction based on depth and value - Depth R = (3 + depth / 4 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY; + Depth R = ((823 + 67 * depth) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY; pos.do_null_move(st); - (ss+1)->skipNullMove = true; + (ss+1)->skipEarlyPruning = 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)->skipEarlyPruning = false; pos.undo_null_move(); if (nullValue >= beta) @@ -667,10 +670,10 @@ namespace { return nullValue; // Do verification search at high depths - ss->skipNullMove = true; + ss->skipEarlyPruning = true; Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta, DEPTH_ZERO) : search(pos, ss, beta-1, beta, depth-R, false); - ss->skipNullMove = false; + ss->skipEarlyPruning = false; if (v >= beta) return nullValue; @@ -683,7 +686,6 @@ namespace { // prune the previous move. if ( !PvNode && depth >= 5 * ONE_PLY - && !ss->skipNullMove && abs(beta) < VALUE_MATE_IN_MAX_PLY) { Value rbeta = std::min(beta + 200, VALUE_INFINITE); @@ -714,12 +716,12 @@ namespace { && (PvNode || ss->staticEval + 256 >= beta)) { Depth d = 2 * (depth - 2 * ONE_PLY) - (PvNode ? DEPTH_ZERO : depth / 2); - ss->skipNullMove = true; + ss->skipEarlyPruning = true; search(pos, ss, alpha, beta, d / 2, true); - ss->skipNullMove = false; + ss->skipEarlyPruning = false; - tte = TT.probe(posKey); - ttMove = tte ? tte->move() : MOVE_NONE; + tte = TT.probe(posKey, ttHit); + ttMove = ttHit ? tte->move() : MOVE_NONE; } moves_loop: // When in check and at SpNode search starts from here @@ -782,7 +784,7 @@ moves_loop: // When in check and at SpNode search starts from here if (thisThread == Threads.main() && Time::now() - SearchTime > 3000) sync_cout << "info depth " << depth / ONE_PLY - << " currmove " << UCI::format_move(move, pos.is_chess960()) + << " currmove " << UCI::move(move, pos.is_chess960()) << " currmovenumber " << moveCount + PVIdx << sync_endl; } @@ -816,9 +818,9 @@ moves_loop: // When in check and at SpNode search starts from here { Value rBeta = ttValue - 2 * depth / ONE_PLY; ss->excludedMove = move; - ss->skipNullMove = true; + ss->skipEarlyPruning = true; value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode); - ss->skipNullMove = false; + ss->skipEarlyPruning = false; ss->excludedMove = MOVE_NONE; if (value < rBeta) @@ -828,9 +830,8 @@ moves_loop: // When in check and at SpNode search starts from here // Update the current move (this must be done after singular extension search) newDepth = depth - ONE_PLY + extension; - // Step 13. Pruning at shallow depth (exclude PV nodes) - if ( !PvNode - && !captureOrPromotion + // Step 13. Pruning at shallow depth + if ( !captureOrPromotion && !inCheck && !dangerous && bestValue > VALUE_MATED_IN_MAX_PLY) @@ -905,7 +906,7 @@ moves_loop: // When in check and at SpNode search starts from here ss->reduction = reduction(improving, depth, moveCount); if ( (!PvNode && cutNode) - || History[pos.piece_on(to_sq(move))][to_sq(move)] < 0) + || History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO) ss->reduction += ONE_PLY; if (move == countermoves[0] || move == countermoves[1]) @@ -915,7 +916,7 @@ moves_loop: // When in check and at SpNode search starts from here 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) + && pos.see(make_move(to_sq(move), from_sq(move))) < VALUE_ZERO) ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); Depth d = std::max(newDepth - ss->reduction, ONE_PLY); @@ -1079,10 +1080,10 @@ moves_loop: // When in check and at SpNode search starts from here 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); + tte->save(posKey, value_to_tt(bestValue, ss->ply), + bestValue >= beta ? BOUND_LOWER : + PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, + depth, bestMove, ss->staticEval, TT.generation()); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1107,11 +1108,11 @@ moves_loop: // When in check and at SpNode search starts from here Move pv[MAX_PLY+1]; StateInfo st; - const TTEntry* tte; + TTEntry* tte; Key posKey; Move ttMove, move, bestMove; Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha; - bool givesCheck, evasionPrunable; + bool ttHit, givesCheck, evasionPrunable; Depth ttDepth; if (PvNode) @@ -1138,12 +1139,12 @@ moves_loop: // When in check and at SpNode search starts from here // Transposition table lookup posKey = pos.key(); - tte = TT.probe(posKey); - ttMove = tte ? tte->move() : MOVE_NONE; - ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_NONE; + tte = TT.probe(posKey, ttHit); + ttMove = ttHit ? tte->move() : MOVE_NONE; + ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; if ( !PvNode - && tte + && ttHit && tte->depth() >= ttDepth && ttValue != VALUE_NONE // Only in case of TT access race && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) @@ -1161,10 +1162,10 @@ moves_loop: // When in check and at SpNode search starts from here } else { - if (tte) + if (ttHit) { // Never assume anything on values stored in TT - if ((ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE) + if ((ss->staticEval = bestValue = tte->eval()) == VALUE_NONE) ss->staticEval = bestValue = evaluate(pos); // Can ttValue be used as a better position evaluation? @@ -1179,9 +1180,9 @@ moves_loop: // When in check and at SpNode search starts from here // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) { - if (!tte) - TT.store(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER, - DEPTH_NONE, MOVE_NONE, ss->staticEval); + if (!ttHit) + tte->save(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER, + DEPTH_NONE, MOVE_NONE, ss->staticEval, TT.generation()); return bestValue; } @@ -1209,8 +1210,7 @@ moves_loop: // When in check and at SpNode search starts from here : pos.gives_check(move, ci); // Futility pruning - if ( !PvNode - && !InCheck + if ( !InCheck && !givesCheck && futilityBase > -VALUE_KNOWN_WIN && !pos.advanced_pawn_push(move)) @@ -1219,13 +1219,13 @@ moves_loop: // When in check and at SpNode search starts from here futilityValue = futilityBase + PieceValue[EG][pos.piece_on(to_sq(move))]; - if (futilityValue < beta) + if (futilityValue <= alpha) { bestValue = std::max(bestValue, futilityValue); continue; } - if (futilityBase < beta && pos.see(move) <= VALUE_ZERO) + if (futilityBase <= alpha && pos.see(move) <= VALUE_ZERO) { bestValue = std::max(bestValue, futilityBase); continue; @@ -1239,8 +1239,7 @@ moves_loop: // When in check and at SpNode search starts from here && !pos.can_castle(pos.side_to_move()); // Don't search moves with negative SEE values - if ( !PvNode - && (!InCheck || evasionPrunable) + if ( (!InCheck || evasionPrunable) && type_of(move) != PROMOTION && pos.see_sign(move) < VALUE_ZERO) continue; @@ -1279,8 +1278,8 @@ moves_loop: // When in check and at SpNode search starts from here } else // Fail high { - TT.store(posKey, value_to_tt(value, ss->ply), BOUND_LOWER, - ttDepth, move, ss->staticEval); + tte->save(posKey, value_to_tt(value, ss->ply), BOUND_LOWER, + ttDepth, move, ss->staticEval, TT.generation()); return value; } @@ -1293,9 +1292,9 @@ moves_loop: // When in check and at SpNode search starts from here if (InCheck && bestValue == -VALUE_INFINITE) return mated_in(ss->ply); // Plies to mate from the root - TT.store(posKey, value_to_tt(bestValue, ss->ply), - PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER, - ttDepth, bestMove, ss->staticEval); + tte->save(posKey, value_to_tt(bestValue, ss->ply), + PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER, + ttDepth, bestMove, ss->staticEval, TT.generation()); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1445,15 +1444,19 @@ moves_loop: // When in check and at SpNode search starts from here ss << "info depth " << d / ONE_PLY << " seldepth " << selDepth << " multipv " << i + 1 - << " score " << ((!tb && i == PVIdx) ? UCI::format_value(v, alpha, beta) : UCI::format_value(v)) - << " nodes " << pos.nodes_searched() + << " score " << UCI::value(v); + + if (!tb && i == PVIdx) + ss << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : ""); + + ss << " nodes " << pos.nodes_searched() << " nps " << pos.nodes_searched() * 1000 / elapsed << " tbhits " << TB::Hits << " time " << elapsed << " pv"; for (size_t j = 0; j < RootMoves[i].pv.size(); ++j) - ss << " " << UCI::format_move(RootMoves[i].pv[j], pos.is_chess960()); + ss << " " << UCI::move(RootMoves[i].pv[j], pos.is_chess960()); } return ss.str(); @@ -1469,15 +1472,15 @@ moves_loop: // When in check and at SpNode search starts from here void RootMove::insert_pv_in_tt(Position& pos) { StateInfo state[MAX_PLY], *st = state; - const TTEntry* tte; size_t idx = 0; for ( ; idx < pv.size(); ++idx) { - tte = TT.probe(pos.key()); + bool ttHit; + TTEntry* tte = TT.probe(pos.key(), ttHit); - 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); + if (!ttHit || tte->move() != pv[idx]) // Don't overwrite correct entries + tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[idx], VALUE_NONE, TT.generation()); assert(MoveList(pos).contains(pv[idx])); @@ -1488,6 +1491,30 @@ void RootMove::insert_pv_in_tt(Position& pos) { } +/// 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, otherwise in case of +/// 'ponder on' we have nothing to think on. + +Move RootMove::extract_ponder_from_tt(Position& pos) +{ + StateInfo st; + bool found; + + assert(pv.size() == 1); + + pos.do_move(pv[0], st); + TTEntry* tte = TT.probe(pos.key(), found); + Move m = found ? tte->move() : MOVE_NONE; + if (!MoveList(pos).contains(m)) + m = MOVE_NONE; + + pos.undo_move(pv[0]); + pv.push_back(m); + return m; +} + + /// Thread::idle_loop() is where the thread is parked when it has no work to do void Thread::idle_loop() {