X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=2fdd2840ea2b38915c453baf46783cc097909b35;hp=eb7666afd5142b85c624fabaeeba71b7dce04b77;hb=3ef4fdeaa01f4d41fc723d54c0a17cea712cf035;hpb=1d0159075e916c738760b788d605b71b3736cb7c diff --git a/src/search.cpp b/src/search.cpp index eb7666af..2fdd2840 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -318,8 +318,8 @@ void init_search() { } -/// perft() is our utility to verify move generation. All the legal moves up to -/// given depth are generated and counted and the sum returned. +/// perft() is our utility to verify move generation. All the leaf nodes up to +/// the given depth are generated and counted and the sum returned. int64_t perft(Position& pos, Depth depth) { @@ -341,7 +341,7 @@ int64_t perft(Position& pos, Depth depth) { for (MoveStack* cur = mlist; cur != last; cur++) { m = cur->move; - pos.do_move(m, st, ci, pos.move_is_check(m, ci)); + pos.do_move(m, st, ci, pos.move_gives_check(m, ci)); sum += perft(pos, depth - ONE_PLY); pos.undo_move(m); } @@ -394,7 +394,7 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { // Read UCI options UCIMultiPV = Options["MultiPV"].value(); - SkillLevel = Options["Skill level"].value(); + SkillLevel = Options["Skill Level"].value(); read_evaluation_uci_options(pos.side_to_move()); Threads.read_uci_options(); @@ -512,7 +512,7 @@ namespace { if (Rml.size() == 0) { cout << "info depth 0 score " - << value_to_uci(pos.is_check() ? -VALUE_MATE : VALUE_DRAW) + << value_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl; return MOVE_NONE; @@ -681,14 +681,14 @@ namespace { ValueType vt; Value bestValue, value, oldAlpha; Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific - bool isPvMove, isCheck, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous, isBadCap; + bool isPvMove, inCheck, singularExtensionNode, givesCheck, captureOrPromotion, dangerous; int moveCount = 0, playedMoveCount = 0; int threadID = pos.thread(); SplitPoint* sp = NULL; refinedValue = bestValue = value = -VALUE_INFINITE; oldAlpha = alpha; - isCheck = pos.is_check(); + inCheck = pos.in_check(); ss->ply = (ss-1)->ply + 1; // Used to send selDepth info to GUI @@ -753,7 +753,7 @@ namespace { } // Step 5. Evaluate the position statically and update parent's gain statistics - if (isCheck) + if (inCheck) ss->eval = ss->evalMargin = VALUE_NONE; else if (tte) { @@ -775,7 +775,7 @@ namespace { // Step 6. Razoring (is omitted in PV nodes) if ( !PvNode && depth < RazorDepth - && !isCheck + && !inCheck && refinedValue + razor_margin(depth) < beta && ttMove == MOVE_NONE && abs(beta) < VALUE_MATE_IN_PLY_MAX @@ -795,7 +795,7 @@ namespace { if ( !PvNode && !ss->skipNullMove && depth < RazorDepth - && !isCheck + && !inCheck && refinedValue - futility_margin(depth, 0) >= beta && abs(beta) < VALUE_MATE_IN_PLY_MAX && pos.non_pawn_material(pos.side_to_move())) @@ -805,7 +805,7 @@ namespace { if ( !PvNode && !ss->skipNullMove && depth > ONE_PLY - && !isCheck + && !inCheck && refinedValue >= beta && abs(beta) < VALUE_MATE_IN_PLY_MAX && pos.non_pawn_material(pos.side_to_move())) @@ -863,7 +863,7 @@ namespace { // Step 9. Internal iterative deepening if ( depth >= IIDDepth[PvNode] && ttMove == MOVE_NONE - && (PvNode || (!isCheck && ss->eval + IIDMargin >= beta))) + && (PvNode || (!inCheck && ss->eval + IIDMargin >= beta))) { Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2); @@ -871,8 +871,8 @@ namespace { search(pos, ss, alpha, beta, d); ss->skipNullMove = false; - ttMove = ss->bestMove; tte = TT.probe(posKey); + ttMove = tte ? tte->move() : MOVE_NONE; } split_point_start: // At split points actual search starts from here @@ -885,8 +885,7 @@ split_point_start: // At split points actual search starts from here singularExtensionNode = !Root && !SpNode && depth >= SingularExtensionDepth[PvNode] - && tte - && tte->move() + && ttMove != MOVE_NONE && !excludedMove // Do not allow recursive singular extension search && (tte->type() & VALUE_TYPE_LOWER) && tte->depth() >= depth - 3 * ONE_PLY; @@ -937,11 +936,11 @@ split_point_start: // At split points actual search starts from here // At Root and at first iteration do a PV search on all the moves to score root moves isPvMove = (PvNode && moveCount <= (Root ? depth <= ONE_PLY ? 1000 : MultiPV : 1)); - moveIsCheck = pos.move_is_check(move, ci); - captureOrPromotion = pos.move_is_capture_or_promotion(move); + givesCheck = pos.move_gives_check(move, ci); + captureOrPromotion = pos.move_is_capture(move) || move_is_promotion(move); // Step 11. Decide the new search depth - ext = extension(pos, move, captureOrPromotion, moveIsCheck, &dangerous); + ext = extension(pos, move, captureOrPromotion, givesCheck, &dangerous); // Singular extension search. If all moves but one fail low on a search of // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move @@ -949,7 +948,7 @@ split_point_start: // At split points actual search starts from here // on all the other moves but the ttMove, if result is lower than ttValue minus // a margin then we extend ttMove. if ( singularExtensionNode - && move == tte->move() + && move == ttMove && ext < ONE_PLY) { Value ttValue = value_from_tt(tte->value(), ss->ply); @@ -975,7 +974,7 @@ split_point_start: // At split points actual search starts from here // Step 12. Futility pruning (is omitted in PV nodes) if ( !PvNode && !captureOrPromotion - && !isCheck + && !inCheck && !dangerous && move != ttMove && !move_is_castle(move)) @@ -1024,18 +1023,8 @@ split_point_start: // At split points actual search starts from here } } - // Bad capture detection. Will be used by prob-cut search - isBadCap = depth >= 3 * ONE_PLY - && depth < 8 * ONE_PLY - && captureOrPromotion - && move != ttMove - && !dangerous - && !move_is_promotion(move) - && abs(alpha) < VALUE_MATE_IN_PLY_MAX - && pos.see_sign(move) < 0; - // Step 13. Make the move - pos.do_move(move, st, ci, moveIsCheck); + pos.do_move(move, st, ci, givesCheck); if (!SpNode && !captureOrPromotion) movesSearched[playedMoveCount++] = move; @@ -1067,7 +1056,6 @@ split_point_start: // At split points actual search starts from here ss->reduction = reduction(depth, moveCount); if (ss->reduction) { - alpha = SpNode ? sp->alpha : alpha; Depth d = newDepth - ss->reduction; value = -search(pos, ss+1, -(alpha+1), -alpha, d); @@ -1078,7 +1066,13 @@ split_point_start: // At split points actual search starts from here // Probcut search for bad captures. If a reduced search returns a value // very below beta then we can (almost) safely prune the bad capture. - if (isBadCap) + if ( depth >= 3 * ONE_PLY + && depth < 8 * ONE_PLY + && mp.isBadCapture() + && move != ttMove + && !dangerous + && !move_is_promotion(move) + && abs(alpha) < VALUE_MATE_IN_PLY_MAX) { ss->reduction = 3 * ONE_PLY; Value rAlpha = alpha - 300; @@ -1202,7 +1196,7 @@ split_point_start: // At split points actual search starts from here // no legal moves, it must be mate or stalemate. // If one move was excluded return fail low score. if (!SpNode && !moveCount) - return excludedMove ? oldAlpha : isCheck ? value_mated_in(ss->ply) : VALUE_DRAW; + return excludedMove ? oldAlpha : inCheck ? value_mated_in(ss->ply) : VALUE_DRAW; // Step 20. Update tables // If the search is not aborted, update the transposition table, @@ -1217,7 +1211,8 @@ split_point_start: // At split points actual search starts from here // Update killers and history only for non capture moves that fails high if ( bestValue >= beta - && !pos.move_is_capture_or_promotion(move)) + && !pos.move_is_capture(move) + && !move_is_promotion(move)) { if (move != ss->killers[0]) { @@ -1257,7 +1252,7 @@ split_point_start: // At split points actual search starts from here StateInfo st; Move ttMove, move; Value bestValue, value, evalMargin, futilityValue, futilityBase; - bool isCheck, enoughMaterial, moveIsCheck, evasionPrunable; + bool inCheck, enoughMaterial, givesCheck, evasionPrunable; const TTEntry* tte; Depth ttDepth; Value oldAlpha = alpha; @@ -1272,8 +1267,8 @@ split_point_start: // At split points actual search starts from here // 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. - isCheck = pos.is_check(); - ttDepth = (isCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS : DEPTH_QS_NO_CHECKS); + inCheck = pos.in_check(); + 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. @@ -1287,7 +1282,7 @@ split_point_start: // At split points actual search starts from here } // Evaluate the position statically - if (isCheck) + if (inCheck) { bestValue = futilityBase = -VALUE_INFINITE; ss->eval = evalMargin = VALUE_NONE; @@ -1337,12 +1332,12 @@ split_point_start: // At split points actual search starts from here { assert(move_is_ok(move)); - moveIsCheck = pos.move_is_check(move, ci); + givesCheck = pos.move_gives_check(move, ci); // Futility pruning if ( !PvNode - && !isCheck - && !moveIsCheck + && !inCheck + && !givesCheck && move != ttMove && enoughMaterial && !move_is_promotion(move) @@ -1367,14 +1362,14 @@ split_point_start: // At split points actual search starts from here } // Detect non-capture evasions that are candidate to be pruned - evasionPrunable = isCheck + evasionPrunable = inCheck && bestValue > VALUE_MATED_IN_PLY_MAX && !pos.move_is_capture(move) && !pos.can_castle(pos.side_to_move()); // Don't search moves with negative SEE values if ( !PvNode - && (!isCheck || evasionPrunable) + && (!inCheck || evasionPrunable) && move != ttMove && !move_is_promotion(move) && pos.see_sign(move) < 0) @@ -1382,10 +1377,11 @@ split_point_start: // At split points actual search starts from here // Don't search useless checks if ( !PvNode - && !isCheck - && moveIsCheck + && !inCheck + && givesCheck && move != ttMove - && !pos.move_is_capture_or_promotion(move) + && !pos.move_is_capture(move) + && !move_is_promotion(move) && ss->eval + PawnValueMidgame / 4 < beta && !check_is_dangerous(pos, move, futilityBase, beta, &bestValue)) { @@ -1399,7 +1395,7 @@ split_point_start: // At split points actual search starts from here ss->currentMove = move; // Make and search the move - pos.do_move(move, st, ci, moveIsCheck); + pos.do_move(move, st, ci, givesCheck); value = -qsearch(pos, ss+1, -beta, -alpha, depth-ONE_PLY); pos.undo_move(move); @@ -1419,7 +1415,7 @@ split_point_start: // At split points actual 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 (isCheck && bestValue == -VALUE_INFINITE) + if (inCheck && bestValue == -VALUE_INFINITE) return value_mated_in(ss->ply); // Update transposition table @@ -1627,8 +1623,8 @@ split_point_start: // At split points actual search starts from here assert(move_is_ok(m)); assert(threat && move_is_ok(threat)); - assert(!pos.move_is_check(m)); - assert(!pos.move_is_capture_or_promotion(m)); + assert(!pos.move_gives_check(m)); + assert(!pos.move_is_capture(m) && !move_is_promotion(m)); assert(!pos.move_is_passed_pawn_push(m)); Square mfrom, mto, tfrom, tto; @@ -2022,7 +2018,7 @@ split_point_start: // At split points actual search starts from here // Don't overwrite existing correct entries if (!tte || tte->move() != pv[ply]) { - v = (pos.is_check() ? VALUE_NONE : evaluate(pos, m)); + v = (pos.in_check() ? VALUE_NONE : evaluate(pos, m)); TT.store(k, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[ply], v, m); } pos.do_move(pv[ply], *st++);