X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=6bdf255c3dafee03b8b2fff95536cc7a7405fba7;hp=ab88142ff8fe305de9a23889afc0b772ad777efa;hb=156635749bfc9fc8e71aa8c44d7bd2cfe7a78457;hpb=45dba12c5b236dd4f6d750b9793b192eaa5e6699 diff --git a/src/search.cpp b/src/search.cpp index ab88142f..6bdf255c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -44,7 +44,6 @@ namespace Search { Color RootColor; Time::point SearchTime; StateStackPtr SetupStates; - MovesVectPtr SetupMoves; } using std::string; @@ -441,6 +440,7 @@ namespace { if ( depth >= 12 && !stop && PVSize == 1 + && bestValue > VALUE_MATED_IN_MAX_PLY && ( RootMoves.size() == 1 || Time::now() - SearchTime > (TimeMgr.available_time() * 20) / 100)) { @@ -523,6 +523,7 @@ namespace { bestValue = -VALUE_INFINITE; ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; ss->ply = (ss-1)->ply + 1; + ss->futilityMoveCount = 0; (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; @@ -533,7 +534,7 @@ namespace { if (!RootNode) { // Step 2. Check for aborted search and immediate draw - if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) + if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) return DrawValue[pos.side_to_move()]; // Step 3. Mate distance pruning. Even if we mate at the next move our score @@ -592,7 +593,7 @@ namespace { // Never assume anything on values stored in TT if ( (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) - eval = ss->staticEval = evaluate(pos, ss->evalMargin); + eval = ss->staticEval = evaluate(pos, ss->evalMargin, &ss->ei); // Can ttValue be used as a better position evaluation? if (ttValue != VALUE_NONE) @@ -602,7 +603,7 @@ namespace { } else { - eval = ss->staticEval = evaluate(pos, ss->evalMargin); + eval = ss->staticEval = evaluate(pos, ss->evalMargin, &ss->ei); TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval, ss->evalMargin); } @@ -643,10 +644,11 @@ namespace { && !ss->skipNullMove && depth < 4 * ONE_PLY && !inCheck - && eval - FutilityMargins[depth][0] >= beta + && eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta && abs(beta) < VALUE_MATE_IN_MAX_PLY + && abs(eval) < VALUE_KNOWN_WIN && pos.non_pawn_material(pos.side_to_move())) - return eval - FutilityMargins[depth][0]; + return eval - futility_margin(depth, (ss-1)->futilityMoveCount); // Step 8. Null move search with verification search (is omitted in PV nodes) if ( !PvNode @@ -679,7 +681,7 @@ namespace { if (nullValue >= VALUE_MATE_IN_MAX_PLY) nullValue = beta; - if (depth < 6 * ONE_PLY) + if (depth < 12 * ONE_PLY) return nullValue; // Do verification search at high depths @@ -746,7 +748,7 @@ namespace { && ttMove == MOVE_NONE && (PvNode || (!inCheck && ss->staticEval + Value(256) >= beta))) { - Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2); + Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); ss->skipNullMove = true; search(pos, ss, alpha, beta, d); @@ -853,14 +855,15 @@ split_point_start: // At split points actual search starts from here newDepth = depth - ONE_PLY + ext; // Step 13. Futility pruning (is omitted in PV nodes) - if ( !captureOrPromotion + if ( !PvNode + && !captureOrPromotion && !inCheck && !dangerous - && move != ttMove) + /* && move != ttMove Already implicit in the next condition */ + && bestValue > VALUE_MATED_IN_MAX_PLY) { // Move count based pruning - if ( !PvNode - && depth < 16 * ONE_PLY + if ( depth < 16 * ONE_PLY && moveCount >= FutilityMoveCounts[depth] && (!threatMove || !refutes(pos, move, threatMove))) { @@ -877,16 +880,21 @@ split_point_start: // At split points actual search starts from here futilityValue = ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount) + Gain[pos.piece_moved(move)][to_sq(move)]; - if (!PvNode && futilityValue < beta) + if (futilityValue < beta) { + bestValue = std::max(bestValue, futilityValue); + if (SpNode) + { splitPoint->mutex.lock(); - + if (bestValue > splitPoint->bestValue) + splitPoint->bestValue = bestValue; + } continue; } // Prune moves with negative SEE at low depths - if ( predictedDepth < 2 * ONE_PLY + if ( predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < 0) { if (SpNode) @@ -894,7 +902,13 @@ split_point_start: // At split points actual search starts from here continue; } + + // We have not pruned the move that will be searched, but remember how + // far in the move list we are to be more aggressive in the child node. + ss->futilityMoveCount = moveCount; } + else + ss->futilityMoveCount = 0; // Check for legality only before to do the move if (!RootNode && !SpNode && !pos.pl_move_is_legal(move, ci.pinned)) @@ -1123,9 +1137,15 @@ split_point_start: // At split points actual search starts from here ss->ply = (ss-1)->ply + 1; // Check for an instant draw or maximum ply reached - if (pos.is_draw() || ss->ply > MAX_PLY) + if (pos.is_draw() || ss->ply > MAX_PLY) return DrawValue[pos.side_to_move()]; + // Decide whether or not to include checks, this fixes also the type of + // TT entry depth that we are going to use. Note that in qsearch we use + // only two types of depth in TT: DEPTH_QS_CHECKS or DEPTH_QS_NO_CHECKS. + ttDepth = InCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS + : DEPTH_QS_NO_CHECKS; + // Transposition table lookup. At PV nodes, we don't use the TT for // pruning, but only for move ordering. posKey = pos.key(); @@ -1133,11 +1153,6 @@ split_point_start: // At split points actual search starts from here ttMove = tte ? tte->move() : MOVE_NONE; ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_NONE; - // Decide whether or not to include checks, this fixes also the type of - // TT entry depth that we are going to use. Note that in qsearch we use - // only two types of depth in TT: DEPTH_QS_CHECKS or DEPTH_QS_NO_CHECKS. - ttDepth = InCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS - : DEPTH_QS_NO_CHECKS; if ( tte && tte->depth() >= ttDepth && ttValue != VALUE_NONE // Only in case of TT access race @@ -1163,10 +1178,10 @@ split_point_start: // At split points actual search starts from here // Never assume anything on values stored in TT if ( (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) - ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); + ss->staticEval = bestValue = evaluate(pos, ss->evalMargin, &ss->ei); } else - ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); + ss->staticEval = bestValue = evaluate(pos, ss->evalMargin, &ss->ei); // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) @@ -1218,10 +1233,11 @@ split_point_start: // At split points actual search starts from here continue; } - // Prune moves with negative or equal SEE + // Prune moves with negative or equal SEE and also moves with positive + // SEE where capturing piece loses a tempo and SEE < beta - futilityBase. if ( futilityBase < beta && depth < DEPTH_ZERO - && pos.see(move) <= 0) + && pos.see(move, beta - futilityBase) <= 0) { bestValue = std::max(bestValue, futilityBase); continue; @@ -1571,7 +1587,7 @@ void RootMove::extract_pv_from_tt(Position& pos) { && pos.is_pseudo_legal(m = tte->move()) // Local copy, TT could change && pos.pl_move_is_legal(m, pos.pinned_pieces()) && ply < MAX_PLY - && (!pos.is_draw() || ply < 2)); + && (!pos.is_draw() || ply < 2)); pv.push_back(MOVE_NONE); // Must be zero-terminating