X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=57a5517614e67c5f9f37febb857b9d2a0b3840d5;hp=9c7190bed0cacb99e7d813df7196e205cb23bac8;hb=68d61b80c60a81055a2ffb2e251a237b979e9b31;hpb=946fa4762539307dcdcb30d08f13d627864e9bcf diff --git a/src/search.cpp b/src/search.cpp index 9c7190be..57a55176 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -134,7 +134,6 @@ namespace { Value DrawValue[COLOR_NB]; HistoryStats History; CounterMovesHistoryStats CounterMovesHistory; - GainsStats Gains; MovesStats Countermoves; template @@ -181,6 +180,17 @@ void Search::init() { } +/// Search::reset() clears all search memory, to obtain reproducible search results + +void Search::reset () { + + TT.clear(); + History.clear(); + CounterMovesHistory.clear(); + Countermoves.clear(); +} + + /// Search::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. template @@ -543,7 +553,7 @@ namespace { goto moves_loop; } - moveCount = quietCount = 0; + moveCount = quietCount = ss->moveCount = 0; bestValue = -VALUE_INFINITE; ss->ply = (ss-1)->ply + 1; @@ -631,7 +641,7 @@ namespace { } } - // Step 5. Evaluate the position statically and update parent's gain statistics + // Step 5. Evaluate the position statically if (inCheck) { ss->staticEval = eval = VALUE_NONE; @@ -660,23 +670,11 @@ namespace { if (ss->skipEarlyPruning) goto moves_loop; - if ( !pos.captured_piece_type() - && ss->staticEval != VALUE_NONE - && (ss-1)->staticEval != VALUE_NONE - && (move = (ss-1)->currentMove) != MOVE_NULL - && move != MOVE_NONE - && type_of(move) == NORMAL) - { - Square to = to_sq(move); - Gains.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); - } - // Step 6. Razoring (skipped when in check) if ( !PvNode && depth < 4 * ONE_PLY && eval + razor_margin(depth) <= alpha - && ttMove == MOVE_NONE - && !pos.pawn_on_7th(pos.side_to_move())) + && ttMove == MOVE_NONE) { if ( depth <= ONE_PLY && eval + razor_margin(3 * ONE_PLY) <= alpha) @@ -751,7 +749,7 @@ namespace { assert((ss-1)->currentMove != MOVE_NONE); assert((ss-1)->currentMove != MOVE_NULL); - MovePicker mp(pos, ttMove, History, CounterMovesHistory, pos.captured_piece_type()); + MovePicker mp(pos, ttMove, History, CounterMovesHistory, PieceValue[MG][pos.captured_piece_type()]); CheckInfo ci(pos); while ((move = mp.next_move()) != MOVE_NONE) @@ -771,9 +769,9 @@ namespace { && !ttMove && (PvNode || ss->staticEval + 256 >= beta)) { - Depth d = 2 * (depth - 2 * ONE_PLY) - (PvNode ? DEPTH_ZERO : depth / 2); + Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); ss->skipEarlyPruning = true; - search(pos, ss, alpha, beta, d / 2, true); + search(pos, ss, alpha, beta, d, true); ss->skipEarlyPruning = false; tte = TT.probe(posKey, ttHit); @@ -823,11 +821,11 @@ moves_loop: // When in check and at SpNode search starts from here if (!pos.legal(move, ci.pinned)) continue; - moveCount = ++splitPoint->moveCount; + ss->moveCount = moveCount = ++splitPoint->moveCount; splitPoint->spinlock.release(); } else - ++moveCount; + ss->moveCount = ++moveCount; if (RootNode) { @@ -846,7 +844,7 @@ moves_loop: // When in check and at SpNode search starts from here captureOrPromotion = pos.capture_or_promotion(move); givesCheck = type_of(move) == NORMAL && !ci.dcCandidates - ? ci.checkSq[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) + ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) : pos.gives_check(move, ci); dangerous = givesCheck @@ -903,8 +901,7 @@ moves_loop: // When in check and at SpNode search starts from here // Futility pruning: parent node if (predictedDepth < 7 * ONE_PLY) { - futilityValue = ss->staticEval + futility_margin(predictedDepth) - + 128 + Gains[pos.moved_piece(move)][to_sq(move)]; + futilityValue = ss->staticEval + futility_margin(predictedDepth) + 256; if (futilityValue <= alpha) { @@ -936,7 +933,7 @@ moves_loop: // When in check and at SpNode search starts from here // Check for legality just before making the move if (!RootNode && !SpNode && !pos.legal(move, ci.pinned)) { - moveCount--; + ss->moveCount = --moveCount; continue; } @@ -961,7 +958,9 @@ moves_loop: // When in check and at SpNode search starts from here [pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO)) ss->reduction += ONE_PLY; - if (move == countermove) + if ( History[pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO + && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq] + [pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO) ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); // Decrease reduction for moves that escape a capture @@ -977,13 +976,6 @@ moves_loop: // When in check and at SpNode search starts from here value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); - // Re-search at intermediate depth if reduction is very high - if (value > alpha && ss->reduction >= 4 * ONE_PLY) - { - Depth d2 = std::max(newDepth - 2 * ONE_PLY, ONE_PLY); - value = -search(pos, ss+1, -(alpha+1), -alpha, d2, true); - } - doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO); ss->reduction = DEPTH_ZERO; } @@ -1269,7 +1261,7 @@ moves_loop: // When in check and at SpNode search starts from here assert(is_ok(move)); givesCheck = type_of(move) == NORMAL && !ci.dcCandidates - ? ci.checkSq[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) + ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) : pos.gives_check(move, ci); // Futility pruning @@ -1433,8 +1425,8 @@ moves_loop: // When in check and at SpNode search starts from here cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); } - // Extra penalty for TT move in previous ply when it gets refuted - if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove) + // Extra penalty for PV move in previous ply when it gets refuted + if (is_ok((ss-2)->currentMove) && (ss-1)->moveCount == 1 && !pos.captured_piece_type()) { Square prevPrevSq = to_sq((ss-2)->currentMove); HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq];