X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=a10e1180c344a3af45a23bf293386d27cc48ddbf;hp=7ff9aaa466902ae5b851ea2c225a853d8416c576;hb=02420d4670e54f41bce5bc6d53fb437b80f9d534;hpb=05c6f7a40b62f286873945f937c2ef3cae183e41 diff --git a/src/search.cpp b/src/search.cpp index 7ff9aaa4..a10e1180 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -91,7 +91,7 @@ namespace { CountermovesStats Countermoves; template - Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth); + Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode); template Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth); @@ -295,14 +295,14 @@ namespace { void id_loop(Position& pos) { - Stack ss[MAX_PLY_PLUS_2]; + Stack stack[MAX_PLY_PLUS_2], *ss = stack+1; // To allow referencing (ss-1) int depth, prevBestMoveChanges; Value bestValue, alpha, beta, delta; - memset(ss, 0, 4 * sizeof(Stack)); + memset(ss-1, 0, 4 * sizeof(Stack)); depth = BestMoveChanges = 0; bestValue = delta = -VALUE_INFINITE; - ss->currentMove = MOVE_NULL; // Hack to skip update gains + (ss-1)->currentMove = MOVE_NULL; // Hack to skip update gains TT.new_search(); History.clear(); Gains.clear(); @@ -349,9 +349,7 @@ namespace { // research with bigger window until not failing high/low anymore. while (true) { - // Search starts from ss+1 to allow referencing (ss-1). This is - // needed by update gains and ss copy when splitting at Root. - bestValue = search(pos, ss+1, alpha, beta, depth * ONE_PLY); + bestValue = search(pos, ss, alpha, beta, depth * ONE_PLY, false); // Bring to front the best move. It is critical that sorting is // done with a stable algorithm because all the values but the first @@ -421,7 +419,7 @@ namespace { rm = *std::find(RootMoves.begin(), RootMoves.end(), skill.best); Log log(Options["Search Log Filename"]); - log << pretty_pv(pos, depth, rm.score, Time::now() - SearchTime, rm.pv.data()) + log << pretty_pv(pos, depth, rm.score, Time::now() - SearchTime, &rm.pv[0]) << std::endl; } @@ -455,11 +453,11 @@ namespace { || Time::now() - SearchTime > (TimeMgr.available_time() * 20) / 100)) { Value rBeta = bestValue - 2 * PawnValueMg; - (ss+1)->excludedMove = RootMoves[0].pv[0]; - (ss+1)->skipNullMove = true; - Value v = search(pos, ss+1, rBeta - 1, rBeta, (depth - 3) * ONE_PLY); - (ss+1)->skipNullMove = false; - (ss+1)->excludedMove = MOVE_NONE; + ss->excludedMove = RootMoves[0].pv[0]; + ss->skipNullMove = true; + Value v = search(pos, ss, rBeta - 1, rBeta, (depth - 3) * ONE_PLY, true); + ss->skipNullMove = false; + ss->excludedMove = MOVE_NONE; if (v < rBeta) stop = true; @@ -487,7 +485,7 @@ namespace { // here: This is taken care of after we return from the split point. template - Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) { + Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode) { const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV || NT == SplitPointRoot); const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot); @@ -681,7 +679,7 @@ namespace { pos.do_null_move(st); (ss+1)->skipNullMove = true; nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) - : - search(pos, ss+1, -beta, -alpha, depth-R); + : - search(pos, ss+1, -beta, -alpha, depth-R, !cutNode); (ss+1)->skipNullMove = false; pos.undo_null_move(); @@ -696,7 +694,7 @@ namespace { // Do verification search at high depths ss->skipNullMove = true; - Value v = search(pos, ss, alpha, beta, depth-R); + Value v = search(pos, ss, alpha, beta, depth-R, false); ss->skipNullMove = false; if (v >= beta) @@ -716,7 +714,7 @@ namespace { && (ss-1)->reduction && threatMove != MOVE_NONE && allows(pos, (ss-1)->currentMove, threatMove)) - return beta - 1; + return alpha; } } @@ -746,7 +744,7 @@ namespace { { ss->currentMove = move; pos.do_move(move, st, ci, pos.move_gives_check(move, ci)); - value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth); + value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode); pos.undo_move(move); if (value >= rbeta) return value; @@ -761,7 +759,7 @@ namespace { Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); ss->skipNullMove = true; - search(pos, ss, alpha, beta, d); + search(pos, ss, alpha, beta, d, true); ss->skipNullMove = false; tte = TT.probe(posKey); @@ -857,7 +855,7 @@ split_point_start: // At split points actual search starts from here Value rBeta = ttValue - int(depth); ss->excludedMove = move; ss->skipNullMove = true; - value = search(pos, ss, rBeta - 1, rBeta, depth / 2); + value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode); ss->skipNullMove = false; ss->excludedMove = MOVE_NONE; @@ -950,6 +948,10 @@ split_point_start: // At split points actual search starts from here && move != ss->killers[1]) { ss->reduction = reduction(depth, moveCount); + + if (!PvNode && cutNode) + ss->reduction += ONE_PLY; + if (move == countermoves[0] || move == countermoves[1]) ss->reduction = std::max(DEPTH_ZERO, ss->reduction-ONE_PLY); @@ -957,7 +959,7 @@ split_point_start: // At split points actual search starts from here if (SpNode) alpha = splitPoint->alpha; - value = -search(pos, ss+1, -(alpha+1), -alpha, d); + value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO); ss->reduction = DEPTH_ZERO; @@ -974,7 +976,7 @@ split_point_start: // At split points actual search starts from here value = newDepth < ONE_PLY ? givesCheck ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) : -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) - : - search(pos, ss+1, -(alpha+1), -alpha, newDepth); + : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode); } // Only for PV nodes do a full PV search on the first move or after a fail @@ -984,7 +986,7 @@ split_point_start: // At split points actual search starts from here value = newDepth < ONE_PLY ? givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) - : - search(pos, ss+1, -beta, -alpha, newDepth); + : - search(pos, ss+1, -beta, -alpha, newDepth, false); // Step 17. Undo move pos.undo_move(move); @@ -1059,7 +1061,7 @@ split_point_start: // At split points actual search starts from here assert(bestValue < beta); thisThread->split(pos, ss, alpha, beta, &bestValue, &bestMove, - depth, threatMove, moveCount, &mp, NT); + depth, threatMove, moveCount, &mp, NT, cutNode); if (bestValue >= beta) break; } @@ -1467,15 +1469,15 @@ split_point_start: // At split points actual search starts from here { // Update occupancy as if the piece and the threat are moving Bitboard occ = pos.pieces() ^ m1from ^ m1to ^ m2from; - Piece piece = pos.piece_on(m1from); + Piece pc = pos.piece_on(m1from); // The moved piece attacks the square 'tto' ? - if (pos.attacks_from(piece, m1to, occ) & m2to) + if (pos.attacks_from(pc, m1to, occ) & m2to) return true; // Scan for possible X-ray attackers behind the moved piece - Bitboard xray = (attacks_bb< ROOK>(m2to, occ) & pos.pieces(color_of(piece), QUEEN, ROOK)) - | (attacks_bb(m2to, occ) & pos.pieces(color_of(piece), QUEEN, BISHOP)); + Bitboard xray = (attacks_bb< ROOK>(m2to, occ) & pos.pieces(color_of(pc), QUEEN, ROOK)) + | (attacks_bb(m2to, occ) & pos.pieces(color_of(pc), QUEEN, BISHOP)); // Verify attackers are triggered by our move and not already existing if (xray && (xray ^ (xray & pos.attacks_from(m2to)))) @@ -1539,7 +1541,7 @@ split_point_start: // At split points actual search starts from here string uci_pv(const Position& pos, int depth, Value alpha, Value beta) { std::stringstream s; - Time::point elaspsed = Time::now() - SearchTime + 1; + Time::point elapsed = Time::now() - SearchTime + 1; size_t uciPVSize = std::min((size_t)Options["MultiPV"], RootMoves.size()); int selDepth = 0; @@ -1564,8 +1566,8 @@ split_point_start: // At split points actual search starts from here << " seldepth " << selDepth << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v)) << " nodes " << pos.nodes_searched() - << " nps " << pos.nodes_searched() * 1000 / elaspsed - << " time " << elaspsed + << " nps " << pos.nodes_searched() * 1000 / elapsed + << " time " << elapsed << " multipv " << i + 1 << " pv"; @@ -1693,11 +1695,11 @@ void Thread::idle_loop() { Threads.mutex.unlock(); - Stack ss[MAX_PLY_PLUS_2]; + Stack stack[MAX_PLY_PLUS_2], *ss = stack+1; // To allow referencing (ss-1) Position pos(*sp->pos, this); - memcpy(ss, sp->ss - 1, 4 * sizeof(Stack)); - (ss+1)->splitPoint = sp; + memcpy(ss-1, sp->ss-1, 4 * sizeof(Stack)); + ss->splitPoint = sp; sp->mutex.lock(); @@ -1707,13 +1709,13 @@ void Thread::idle_loop() { switch (sp->nodeType) { case Root: - search(pos, ss+1, sp->alpha, sp->beta, sp->depth); + search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); break; case PV: - search(pos, ss+1, sp->alpha, sp->beta, sp->depth); + search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); break; case NonPV: - search(pos, ss+1, sp->alpha, sp->beta, sp->depth); + search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); break; default: assert(false);