X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=1582b7bc01e841468227e6ca3fd1fd4188db6c1a;hp=92d2c75ed2c6fd5a3ff3b89d376e60c704c048f4;hb=72c7595f8ac72c7831ee319b8b0bc46404c5fc27;hpb=bfcfaf71018b3aed274ebd544a10c4508718e7de diff --git a/src/search.cpp b/src/search.cpp index 92d2c75e..1582b7bc 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -149,16 +149,6 @@ namespace { // evaluation of the position is more than NullMoveMargin below beta. const Value NullMoveMargin = Value(0x300); - //Null move search refutes move when Nullvalue >= Beta - Delta. Index is depth - //in full plies. Last index is 9+. - const Value NullMoveDeltaMidgame[] = - { Value(-8), Value( 6), Value(-15), Value( 9), Value(21), - Value(34), Value(54), Value( 59), Value(61), Value(61) }; - - const Value NullMoveDeltaEndgame[] = - { Value( 6), Value( 0), Value(-13), Value(-9), Value(-35), - Value(12), Value(24), Value( 9), Value( 5), Value( 5) }; - // Pruning criterions. See the code and comments in ok_to_prune() to // understand their precise meaning. const bool PruneEscapeMoves = false; @@ -203,7 +193,6 @@ namespace { // Iteration counters int Iteration; - bool LastIterations; BetaCounterType BetaCounter; // Scores and number of times the best move changed for each iteration: @@ -217,7 +206,7 @@ namespace { int SearchStartTime; int MaxNodes, MaxDepth; int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime; - Move BestRootMove, PonderMove, EasyMove; + Move EasyMove; int RootMoveNumber; bool InfiniteSearch; bool PonderSearch; @@ -266,7 +255,7 @@ namespace { Depth depth, int ply, int threadID); void sp_search(SplitPoint *sp, int threadID); void sp_search_pv(SplitPoint *sp, int threadID); - void init_node(const Position &pos, SearchStack ss[], int ply, int threadID); + void init_node(SearchStack ss[], int ply, int threadID); void update_pv(SearchStack ss[], int ply); void sp_update_pv(SearchStack *pss, SearchStack ss[], int ply); bool connected_moves(const Position &pos, Move m1, Move m2); @@ -336,7 +325,6 @@ void SearchStack::init(int ply) { pv[ply] = pv[ply + 1] = MOVE_NONE; currentMove = threatMove = MOVE_NONE; reduction = Depth(0); - currentMoveCaptureValue = Value(0); } void SearchStack::initKillers() { @@ -379,8 +367,6 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, // Initialize global search variables Idle = false; SearchStartTime = get_system_time(); - BestRootMove = MOVE_NONE; - PonderMove = MOVE_NONE; EasyMove = MOVE_NONE; for (int i = 0; i < THREAD_MAX; i++) { @@ -671,7 +657,6 @@ namespace { ValueByIteration[0] = Value(0); ValueByIteration[1] = rml.get_move_score(0); Iteration = 1; - LastIterations = false; EasyMove = rml.scan_for_easy_move(); @@ -726,9 +711,6 @@ namespace { ExtraSearchTime = BestMoveChangesByIteration[Iteration] * (MaxSearchTime / 2) + BestMoveChangesByIteration[Iteration-1] * (MaxSearchTime / 3); - // Try to guess if the current iteration is the last one or the last two - LastIterations = (current_search_time() > ((MaxSearchTime + ExtraSearchTime)*58) / 128); - // Stop search if most of MaxSearchTime is consumed at the end of the // iteration. We probably don't have enough time to search the first // move at the next iteration anyway. @@ -765,6 +747,11 @@ namespace { << " hashfull " << TT.full() << std::endl; // Print the best move and the ponder move to the standard output + if (ss[0].pv[0] == MOVE_NONE) + { + ss[0].pv[0] = rml.get_move(0); + ss[0].pv[1] = MOVE_NONE; + } std::cout << "bestmove " << ss[0].pv[0]; if (ss[0].pv[1] != MOVE_NONE) std::cout << " ponder " << ss[0].pv[1]; @@ -968,7 +955,7 @@ namespace { // Initialize, and make an early exit in case of an aborted search, // an instant draw, maximum ply reached, etc. - init_node(pos, ss, ply, threadID); + init_node(ss, ply, threadID); // After init_node() that calls poll() if (AbortSearch || thread_should_stop(threadID)) @@ -1027,12 +1014,6 @@ namespace { movesSearched[moveCount++] = ss[ply].currentMove = move; - if (moveIsCapture) - ss[ply].currentMoveCaptureValue = - move_is_ep(move)? PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move)); - else - ss[ply].currentMoveCaptureValue = Value(0); - // Decide the new search depth bool dangerous; Depth ext = extension(pos, move, true, moveIsCapture, moveIsCheck, singleReply, mateThreat, &dangerous); @@ -1164,7 +1145,7 @@ namespace { // Initialize, and make an early exit in case of an aborted search, // an instant draw, maximum ply reached, etc. - init_node(pos, ss, ply, threadID); + init_node(ss, ply, threadID); // After init_node() that calls poll() if (AbortSearch || thread_should_stop(threadID)) @@ -1207,19 +1188,13 @@ namespace { && ok_to_do_nullmove(pos) && approximateEval >= beta - NullMoveMargin) { - //Calculate correct delta. Idea and tuning from Joona Kiiski. - ScaleFactor factor[2] = { SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL }; - Phase phase = pos.game_phase(); - int i = Min(depth / OnePly, 9); - Value delta = scale_by_game_phase(NullMoveDeltaMidgame[i], NullMoveDeltaEndgame[i], phase, factor); - ss[ply].currentMove = MOVE_NULL; StateInfo st; pos.do_null_move(st); - int R = (depth >= 4 * OnePly ? 4 : 3); // Null move dynamic reduction + int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction - Value nullValue = -search(pos, ss, -(beta-delta-1), depth-R*OnePly, ply+1, false, threadID); + Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID); pos.undo_null_move(); @@ -1227,7 +1202,7 @@ namespace { { /* Do not return unproven mates */ } - else if (nullValue >= beta - delta) + else if (nullValue >= beta) { if (depth < 6 * OnePly) return beta; @@ -1263,8 +1238,8 @@ namespace { { Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID); if ( (v < beta - RazorMargin - RazorMargin / 4) - || (depth < 3*OnePly && v < beta - RazorMargin) - || (depth < 2*OnePly && v < beta - RazorMargin / 2)) + || (depth <= 2*OnePly && v < beta - RazorMargin) + || (depth <= OnePly && v < beta - RazorMargin / 2)) return v; } @@ -1412,6 +1387,9 @@ namespace { } TT.store(pos, value_to_tt(bestValue, ply), depth, m, VALUE_TYPE_LOWER); } + + assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); + return bestValue; } @@ -1431,7 +1409,7 @@ namespace { // Initialize, and make an early exit in case of an aborted search, // an instant draw, maximum ply reached, etc. - init_node(pos, ss, ply, threadID); + init_node(ss, ply, threadID); // After init_node() that calls poll() if (AbortSearch || thread_should_stop(threadID)) @@ -1440,15 +1418,39 @@ namespace { if (pos.is_draw()) return VALUE_DRAW; - // Transposition table lookup - const TTEntry* tte = TT.retrieve(pos); - if (tte && ok_to_use_TT(tte, depth, beta, ply)) - return value_from_tt(tte->value(), ply); + // Transposition table lookup, only when not in PV + TTEntry* tte = NULL; + bool pvNode = (beta - alpha != 1); + if (!pvNode) + { + tte = TT.retrieve(pos); + if (tte && ok_to_use_TT(tte, depth, beta, ply)) + { + assert(tte->type() != VALUE_TYPE_EVAL); + + return value_from_tt(tte->value(), ply); + } + } // Evaluate the position statically EvalInfo ei; + Value staticValue; bool isCheck = pos.is_check(); - Value staticValue = (isCheck ? -VALUE_INFINITE : evaluate(pos, ei, threadID)); + ei.futilityMargin = Value(0); // Manually initialize futilityMargin + + if (isCheck) + staticValue = -VALUE_INFINITE; + + else if (tte && tte->type() == VALUE_TYPE_EVAL) + { + // Use the cached evaluation score if possible + assert(tte->value() == evaluate(pos, ei, threadID)); + assert(ei.futilityMargin == Value(0)); + + staticValue = tte->value(); + } + else + staticValue = evaluate(pos, ei, threadID); if (ply == PLY_MAX - 1) return evaluate(pos, ei, threadID); @@ -1458,7 +1460,13 @@ namespace { Value bestValue = staticValue; if (bestValue >= beta) + { + // Store the score to avoid a future costly evaluation() call + if (!isCheck && !tte && ei.futilityMargin == 0) + TT.store(pos, value_to_tt(bestValue, ply), Depth(-127*OnePly), MOVE_NONE, VALUE_TYPE_EVAL); + return bestValue; + } if (bestValue > alpha) alpha = bestValue; @@ -1466,8 +1474,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth == 0) will be generated. - bool pvNode = (beta - alpha != 1); - MovePicker mp = MovePicker(pos, pvNode, MOVE_NONE, EmptySearchStack, depth, isCheck ? NULL : &ei); + MovePicker mp = MovePicker(pos, pvNode, MOVE_NONE, EmptySearchStack, depth); Move move; int moveCount = 0; Bitboard dcCandidates = mp.discovered_check_candidates(); @@ -1544,7 +1551,14 @@ namespace { assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); // Update transposition table - TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE, VALUE_TYPE_EXACT); + if (!pvNode) + { + Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1)); + if (bestValue < beta) + TT.store(pos, value_to_tt(bestValue, ply), d, MOVE_NONE, VALUE_TYPE_UPPER); + else + TT.store(pos, value_to_tt(bestValue, ply), d, MOVE_NONE, VALUE_TYPE_LOWER); + } // Update killers only for good check moves Move m = ss[ply].currentMove; @@ -1700,12 +1714,6 @@ namespace { assert(move_is_ok(move)); - if (moveIsCapture) - ss[sp->ply].currentMoveCaptureValue = - move_is_ep(move)? PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move)); - else - ss[sp->ply].currentMoveCaptureValue = Value(0); - lock_grab(&(sp->lock)); int moveCount = ++sp->moves; lock_release(&(sp->lock)); @@ -1996,7 +2004,7 @@ namespace { // NodesBetweenPolls nodes, init_node() also calls poll(), which polls // for user input and checks whether it is time to stop the search. - void init_node(const Position &pos, SearchStack ss[], int ply, int threadID) { + void init_node(SearchStack ss[], int ply, int threadID) { assert(ply >= 0 && ply < PLY_MAX); assert(threadID >= 0 && threadID < ActiveThreads); @@ -2421,7 +2429,7 @@ namespace { || ( !FailHigh && !fail_high_ply_1() && !Problem && t > 6*(MaxSearchTime + ExtraSearchTime)); - if ( (Iteration >= 2 && (!InfiniteSearch && overTime)) + if ( (Iteration >= 3 && (!InfiniteSearch && overTime)) || (ExactMaxTime && t >= ExactMaxTime) || (Iteration >= 3 && MaxNodes && nodes_searched() >= MaxNodes)) AbortSearch = true; @@ -2435,7 +2443,7 @@ namespace { void ponderhit() { int t = current_search_time(); PonderSearch = false; - if(Iteration >= 2 && + if(Iteration >= 3 && (!InfiniteSearch && (StopOnPonderhit || t > AbsoluteMaxSearchTime || (RootMoveNumber == 1 &&