X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=fd833b812d9935c5fcdec4ab105b8cce5a689034;hb=b1c8840f104d4d36b3f9a420b8b26a5e94c6dc18;hp=af7f801ffe2da43e713f8213972ce9ce12d2dd69;hpb=d58e83695f1dbe5bb75ca9e5d6775757b5fd5f7a;p=stockfish diff --git a/src/search.cpp b/src/search.cpp index af7f801f..fd833b81 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -165,7 +165,7 @@ namespace { uint64_t perft(Position& pos, Depth depth) { StateInfo st; - ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize); uint64_t cnt, nodes = 0; const bool leaf = (depth == 2); @@ -597,7 +597,7 @@ namespace { Move pv[MAX_PLY+1], capturesSearched[32], quietsSearched[64]; StateInfo st; - ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize); TTEntry* tte; Key posKey; @@ -612,13 +612,12 @@ namespace { // Step 1. Initialize node Thread* thisThread = pos.this_thread(); - ss->inCheck = pos.checkers(); - priorCapture = pos.captured_piece(); - Color us = pos.side_to_move(); - moveCount = captureCount = quietCount = ss->moveCount = 0; - bestValue = -VALUE_INFINITE; - maxValue = VALUE_INFINITE; - ss->distanceFromPv = (PvNode ? 0 : ss->distanceFromPv); + ss->inCheck = pos.checkers(); + priorCapture = pos.captured_piece(); + Color us = pos.side_to_move(); + moveCount = captureCount = quietCount = ss->moveCount = 0; + bestValue = -VALUE_INFINITE; + maxValue = VALUE_INFINITE; // Check for the available remaining time if (thisThread == Threads.main()) @@ -917,6 +916,7 @@ namespace { return probCutBeta; assert(probCutBeta < VALUE_INFINITE); + MovePicker mp(pos, ttMove, probCutBeta - ss->staticEval, &captureHistory); int probCutCount = 0; bool ttPv = ss->ttPv; @@ -1121,6 +1121,7 @@ moves_loop: // When in check, search starts from here { Value singularBeta = ttValue - ((formerPv + 4) * depth) / 2; Depth singularDepth = (depth - 1 + 3 * formerPv) / 2; + ss->excludedMove = move; value = search(pos, ss, singularBeta - 1, singularBeta, singularDepth, cutNode); ss->excludedMove = MOVE_NONE; @@ -1129,6 +1130,8 @@ moves_loop: // When in check, search starts from here { extension = 1; singularQuietLMR = !ttCapture; + if (!PvNode && value < singularBeta - 140) + extension = 2; } // Multi-cut pruning @@ -1152,16 +1155,6 @@ moves_loop: // When in check, search starts from here } } - // Check extension (~2 Elo) - else if ( givesCheck - && (pos.is_discovered_check_on_king(~us, move) || pos.see_ge(move))) - extension = 1; - - // Last captures extension - else if ( PieceValue[EG][pos.captured_piece()] > PawnValueEg - && pos.non_pawn_material() <= 2 * RookValueMg) - extension = 1; - // Add extension to new depth newDepth += extension; @@ -1178,8 +1171,6 @@ moves_loop: // When in check, search starts from here // Step 15. Make the move pos.do_move(move, st, givesCheck); - (ss+1)->distanceFromPv = ss->distanceFromPv + moveCount - 1; - // Step 16. Late moves reduction / extension (LMR, ~200 Elo) // We use various heuristics for the sons of a node after the first son has // been searched. In general we would like to reduce them, but there are many @@ -1191,7 +1182,8 @@ moves_loop: // When in check, search starts from here || ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha || cutNode || (!PvNode && !formerPv && captureHistory[movedPiece][to_sq(move)][type_of(pos.captured_piece())] < 3678) - || thisThread->ttHitAverage < 432 * TtHitAverageResolution * TtHitAverageWindow / 1024)) + || thisThread->ttHitAverage < 432 * TtHitAverageResolution * TtHitAverageWindow / 1024) + && (!PvNode || ss->ply > 1 || thisThread->id() % 4 != 3)) { Depth r = reduction(improving, depth, moveCount); @@ -1205,15 +1197,19 @@ moves_loop: // When in check, search starts from here // Decrease reduction if position is or has been on the PV // and node is not likely to fail low. (~10 Elo) - if (ss->ttPv && !likelyFailLow) + if ( ss->ttPv + && !likelyFailLow) r -= 2; // Increase reduction at root and non-PV nodes when the best move does not change frequently - if ((rootNode || !PvNode) && thisThread->rootDepth > 10 && thisThread->bestMoveChanges <= 2) + if ( (rootNode || !PvNode) + && thisThread->rootDepth > 10 + && thisThread->bestMoveChanges <= 2) r++; // More reductions for late moves if position was not in previous PV - if (moveCountPruning && !formerPv) + if ( moveCountPruning + && !formerPv) r++; // Decrease reduction if opponent's move count is high (~5 Elo) @@ -1226,7 +1222,7 @@ moves_loop: // When in check, search starts from here if (captureOrPromotion) { - // Unless giving check, this capture is likely bad + // Increase reduction for non-checking captures likely to be bad if ( !givesCheck && ss->staticEval + PieceValue[EG][pos.captured_piece()] + 210 * depth <= alpha) r++; @@ -1246,7 +1242,7 @@ moves_loop: // When in check, search starts from here // Decrease reduction for moves that escape a capture. Filter out // castling moves, because they are coded as "king captures rook" and - // hence break make_move(). (~2 Elo) + // hence break reverse_move() (~2 Elo) else if ( type_of(move) == NORMAL && !pos.see_ge(reverse_move(move))) r -= 2 + ss->ttPv - (type_of(movedPiece) == PAWN); @@ -1274,10 +1270,10 @@ moves_loop: // When in check, search starts from here r -= ss->statScore / 14790; } - // In general we want to cap the LMR depth search at newDepth. But for nodes - // close to the principal variation the cap is at (newDepth + 1), which will - // allow these nodes to be searched deeper than the pv (up to 4 plies deeper). - Depth d = std::clamp(newDepth - r, 1, newDepth + ((ss+1)->distanceFromPv <= 4)); + // In general we want to cap the LMR depth search at newDepth. But if + // reductions are really negative and movecount is low, we allow this move + // to be searched deeper than the first move. + Depth d = std::clamp(newDepth - r, 1, newDepth + (r < -1 && moveCount <= 5)); value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); @@ -1408,8 +1404,9 @@ moves_loop: // When in check, search starts from here assert(moveCount || !ss->inCheck || excludedMove || !MoveList(pos).size()); if (!moveCount) - bestValue = excludedMove ? alpha - : ss->inCheck ? mated_in(ss->ply) : VALUE_DRAW; + bestValue = excludedMove ? alpha : + ss->inCheck ? mated_in(ss->ply) + : VALUE_DRAW; // If there is a move which produces search value greater than alpha we update stats of searched moves else if (bestMove) @@ -1459,7 +1456,7 @@ moves_loop: // When in check, search starts from here Move pv[MAX_PLY+1]; StateInfo st; - ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize); TTEntry* tte; Key posKey; @@ -1965,7 +1962,7 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { bool RootMove::extract_ponder_from_tt(Position& pos) { StateInfo st; - ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize); bool ttHit;