X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=1be87a8107363f376a8da4404cf4761339d995af;hp=548ea9143d37c48f3aeec316744803a797c13aa1;hb=8db75dd9ec05410136898aa2f8c6dc720b755eb8;hpb=65c3bb8586eba11277f8297ef0f55c121772d82c diff --git a/src/search.cpp b/src/search.cpp index 548ea914..1be87a81 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -101,7 +101,7 @@ namespace { template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode, bool skipEarlyPruning); - template + template Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth = DEPTH_ZERO); Value value_to_tt(Value v, int ply); @@ -351,10 +351,7 @@ void Thread::search() { ct = Options["Contempt"] * PawnValueEg / 100; // From centipawns // Adjust contempt based on current bestValue (dynamic contempt) - int sign = (bestValue > 0) - (bestValue < 0); - ct += bestValue > 500 ? 70 : - bestValue < -500 ? -70 : - bestValue / 10 + sign * int(std::round(3.22 * log(1 + abs(bestValue)))); + ct += int(std::round(48 * atan(float(bestValue) / 128))); Eval::Contempt = (us == WHITE ? make_score(ct, ct / 2) : -make_score(ct, ct / 2)); @@ -657,6 +654,7 @@ namespace { if (inCheck) { ss->staticEval = eval = VALUE_NONE; + improving = false; goto moves_loop; } else if (ttHit) @@ -681,7 +679,6 @@ namespace { } improving = ss->staticEval >= (ss-2)->staticEval - /* || ss->staticEval == VALUE_NONE Already implicit in the previous condition */ ||(ss-2)->staticEval == VALUE_NONE; if (skipEarlyPruning || !pos.non_pawn_material(pos.side_to_move())) @@ -693,12 +690,12 @@ namespace { { if ( depth == ONE_PLY && eval + RazorMargin1 <= alpha) - return qsearch(pos, ss, alpha, alpha+1); + return qsearch(pos, ss, alpha, alpha+1); else if (eval + RazorMargin2 <= alpha) { Value ralpha = alpha - RazorMargin2; - Value v = qsearch(pos, ss, ralpha, ralpha+1); + Value v = qsearch(pos, ss, ralpha, ralpha+1); if (v <= ralpha) return v; @@ -727,7 +724,7 @@ namespace { ss->contHistory = thisThread->contHistory[NO_PIECE][0].get(); pos.do_null_move(st); - Value nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1) + Value nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1) : - search(pos, ss+1, -beta, -beta+1, depth-R, !cutNode, true); pos.undo_null_move(); @@ -745,7 +742,7 @@ namespace { thisThread->nmp_ply = ss->ply + 3 * (depth-R) / 4; thisThread->nmp_odd = ss->ply % 2; - Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta) + Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta) : search(pos, ss, beta-1, beta, depth-R, false, true); thisThread->nmp_odd = thisThread->nmp_ply = 0; @@ -764,12 +761,12 @@ namespace { { assert(is_ok((ss-1)->currentMove)); - Value rbeta = std::min(beta + 200, VALUE_INFINITE); + Value rbeta = std::min(beta + 216 - 48 * improving, VALUE_INFINITE); MovePicker mp(pos, ttMove, rbeta - ss->staticEval, &thisThread->captureHistory); int probCutCount = 0; while ( (move = mp.next_move()) != MOVE_NONE - && probCutCount < depth / ONE_PLY - 3) + && probCutCount < 3) if (pos.legal(move)) { probCutCount++; @@ -781,15 +778,11 @@ namespace { pos.do_move(move, st); - // Perform a preliminary search at depth 1 to verify that the move holds. - // We will only do this search if the depth is not 5, thus avoiding two - // searches at depth 1 in a row. - if (depth != 5 * ONE_PLY) - value = -search(pos, ss+1, -rbeta, -rbeta+1, ONE_PLY, !cutNode, true); + // Perform a preliminary qsearch to verify that the move holds + value = -qsearch(pos, ss+1, -rbeta, -rbeta+1); - // If the first search was skipped or was performed and held, perform - // the regular search. - if (depth == 5 * ONE_PLY || value >= rbeta) + // If the qsearch held perform the regular search + if (value >= rbeta) value = -search(pos, ss+1, -rbeta, -rbeta+1, depth - 4 * ONE_PLY, !cutNode, false); pos.undo_move(move); @@ -819,9 +812,6 @@ moves_loop: // When in check, search starts from here MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &thisThread->captureHistory, contHist, countermove, ss->killers); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc - improving = ss->staticEval >= (ss-2)->staticEval - /* || ss->staticEval == VALUE_NONE Already implicit in the previous condition */ - ||(ss-2)->staticEval == VALUE_NONE; singularExtensionNode = !rootNode && depth >= 8 * ONE_PLY @@ -1019,10 +1009,8 @@ moves_loop: // When in check, search starts from here // Step 17. Full depth search when LMR is skipped or fails high if (doFullDepthSearch) - value = newDepth < ONE_PLY ? - givesCheck ? -qsearch(pos, ss+1, -(alpha+1), -alpha) - : -qsearch(pos, ss+1, -(alpha+1), -alpha) - : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode, false); + value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha) + : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode, false); // For PV nodes only, do a full PV search on the first move or after a fail // high (in the latter case search only if value < beta), otherwise let the @@ -1032,10 +1020,8 @@ moves_loop: // When in check, search starts from here (ss+1)->pv = pv; (ss+1)->pv[0] = MOVE_NONE; - value = newDepth < ONE_PLY ? - givesCheck ? -qsearch(pos, ss+1, -beta, -alpha) - : -qsearch(pos, ss+1, -beta, -alpha) - : - search(pos, ss+1, -beta, -alpha, newDepth, false, false); + value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha) + : - search(pos, ss+1, -beta, -alpha, newDepth, false, false); } // Step 18. Undo move @@ -1164,17 +1150,16 @@ moves_loop: // When in check, search starts from here // qsearch() is the quiescence search function, which is called by the main // search function with depth zero, or recursively with depth less than ONE_PLY. - - template + template Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) { const bool PvNode = NT == PV; + const bool inCheck = bool(pos.checkers()); assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); assert(PvNode || (alpha == beta - 1)); assert(depth <= DEPTH_ZERO); assert(depth / ONE_PLY * ONE_PLY == depth); - assert(InCheck == bool(pos.checkers())); Move pv[MAX_PLY+1]; StateInfo st; @@ -1200,14 +1185,14 @@ moves_loop: // When in check, search starts from here // Check for an immediate draw or maximum ply reached if ( pos.is_draw(ss->ply) || ss->ply >= MAX_PLY) - return (ss->ply >= MAX_PLY && !InCheck) ? evaluate(pos) : VALUE_DRAW; + return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) : VALUE_DRAW; assert(0 <= ss->ply && ss->ply < MAX_PLY); // 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 + ttDepth = inCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS : DEPTH_QS_NO_CHECKS; // Transposition table lookup posKey = pos.key(); @@ -1224,7 +1209,7 @@ moves_loop: // When in check, search starts from here return ttValue; // Evaluate the position statically - if (InCheck) + if (inCheck) { ss->staticEval = VALUE_NONE; bestValue = futilityBase = -VALUE_INFINITE; @@ -1279,7 +1264,7 @@ moves_loop: // When in check, search starts from here moveCount++; // Futility pruning - if ( !InCheck + if ( !inCheck && !givesCheck && futilityBase > -VALUE_KNOWN_WIN && !pos.advanced_pawn_push(move)) @@ -1302,13 +1287,13 @@ moves_loop: // When in check, search starts from here } // Detect non-capture evasions that are candidates to be pruned - evasionPrunable = InCheck + evasionPrunable = inCheck && (depth != DEPTH_ZERO || moveCount > 2) && bestValue > VALUE_MATED_IN_MAX_PLY && !pos.capture(move); // Don't search moves with negative SEE values - if ( (!InCheck || evasionPrunable) + if ( (!inCheck || evasionPrunable) && !pos.see_ge(move)) continue; @@ -1326,8 +1311,7 @@ moves_loop: // When in check, search starts from here // Make and search the move pos.do_move(move, st, givesCheck); - value = givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY) - : -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY); + value = -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY); pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1360,7 +1344,7 @@ moves_loop: // When in check, search starts from here // All legal moves have been searched. A special case: If we're in check // and no legal moves were found, it is checkmate. - if (InCheck && bestValue == -VALUE_INFINITE) + if (inCheck && bestValue == -VALUE_INFINITE) return mated_in(ss->ply); // Plies to mate from the root tte->save(posKey, value_to_tt(bestValue, ss->ply), @@ -1513,7 +1497,7 @@ void MainThread::check_time() { return; // When using nodes, ensure checking rate is not lower than 0.1% of nodes - callsCnt = Limits.nodes ? std::min(4096, int(Limits.nodes / 1024)) : 4096; + callsCnt = Limits.nodes ? std::min(1024, int(Limits.nodes / 1024)) : 1024; static TimePoint lastInfoTime = now();