X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=cae8a6845626e7db07a3bd82a08332eac6322a04;hb=242a7d9fead561488ca176a4687deef8859918f2;hp=7c839dfc89f52ec62d33b0ae98ac8654688e4759;hpb=1c0b7bdf4f77b8160cebe8af96b28230e870a136;p=stockfish diff --git a/src/search.cpp b/src/search.cpp index 7c839dfc..cae8a684 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -335,7 +335,7 @@ void Thread::search() { // for match (TC 60+0.6) results spanning a wide range of k values. PRNG rng(now()); double floatLevel = Options["UCI_LimitStrength"] ? - Utility::clamp(std::pow((Options["UCI_Elo"] - 1346.6) / 143.4, 1 / 0.806), 0.0, 20.0) : + std::clamp(std::pow((Options["UCI_Elo"] - 1346.6) / 143.4, 1 / 0.806), 0.0, 20.0) : double(Options["Skill Level"]); int intLevel = int(floatLevel) + ((floatLevel - int(floatLevel)) * 1024 > rng.rand() % 1024 ? 1 : 0); @@ -508,7 +508,7 @@ void Thread::search() { { double fallingEval = (318 + 6 * (mainThread->bestPreviousScore - bestValue) + 6 * (mainThread->iterValue[iterIdx] - bestValue)) / 825.0; - fallingEval = Utility::clamp(fallingEval, 0.5, 1.5); + fallingEval = std::clamp(fallingEval, 0.5, 1.5); // If the bestMove is stable over several iterations, reduce time accordingly timeReduction = lastBestMoveDepth + 9 < completedDepth ? 1.92 : 0.95; @@ -807,8 +807,9 @@ namespace { && eval <= alpha - RazorMargin) return qsearch(pos, ss, alpha, beta); - improving = (ss-2)->staticEval == VALUE_NONE ? (ss->staticEval > (ss-4)->staticEval - || (ss-4)->staticEval == VALUE_NONE) : ss->staticEval > (ss-2)->staticEval; + improving = (ss-2)->staticEval == VALUE_NONE + ? ss->staticEval > (ss-4)->staticEval || (ss-4)->staticEval == VALUE_NONE + : ss->staticEval > (ss-2)->staticEval; // Step 8. Futility pruning: child node (~50 Elo) if ( !PvNode @@ -879,8 +880,8 @@ namespace { // there and in further interactions with transposition table cutoff depth is set to depth - 3 // because probCut search has depth set to depth - 4 but we also do a move before it // so effective depth is equal to depth - 3 - && !( ttHit - && tte->depth() >= depth - 3 + && !( ttHit + && tte->depth() >= depth - 3 && ttValue != VALUE_NONE && ttValue < probCutBeta)) { @@ -939,16 +940,6 @@ namespace { } } - // Step 11. Internal iterative deepening (~1 Elo) - if (depth >= 7 && !ttMove) - { - search(pos, ss, alpha, beta, depth - 7, cutNode); - - tte = TT.probe(posKey, ttHit); - ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE; - ttMove = ttHit ? tte->move() : MOVE_NONE; - } - moves_loop: // When in check, search starts from here const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory, @@ -972,7 +963,7 @@ moves_loop: // When in check, search starts from here // Mark this node as being searched ThreadHolding th(thisThread, posKey, ss->ply); - // Step 12. Loop through all pseudo-legal moves until no moves remain + // Step 11. Loop through all pseudo-legal moves until no moves remain // or a beta cutoff occurs. while ((move = mp.next_move(moveCountPruning)) != MOVE_NONE) { @@ -1010,7 +1001,7 @@ moves_loop: // When in check, search starts from here // Calculate new depth for this move newDepth = depth - 1; - // Step 13. Pruning at shallow depth (~200 Elo) + // Step 12. Pruning at shallow depth (~200 Elo) if ( !rootNode && pos.non_pawn_material(us) && bestValue > VALUE_TB_LOSS_IN_MAX_PLY) @@ -1068,7 +1059,7 @@ moves_loop: // When in check, search starts from here } } - // Step 14. Extensions (~75 Elo) + // Step 13. Extensions (~75 Elo) // Singular extension search (~70 Elo). If all moves but one fail low on a // search of (alpha-s, beta-s), and just one fails high on (alpha, beta), @@ -1151,10 +1142,10 @@ moves_loop: // When in check, search starts from here [movedPiece] [to_sq(move)]; - // Step 15. Make the move + // Step 14. Make the move pos.do_move(move, st, givesCheck); - // Step 16. Reduced depth search (LMR, ~200 Elo). If the move fails high it will be + // Step 15. Reduced depth search (LMR, ~200 Elo). If the move fails high it will be // re-searched at full depth. if ( depth >= 3 && moveCount > 1 + 2 * rootNode + 2 * (PvNode && abs(bestValue) < 2) @@ -1242,7 +1233,7 @@ moves_loop: // When in check, search starts from here r++; } - Depth d = Utility::clamp(newDepth - r, 1, newDepth); + Depth d = std::clamp(newDepth - r, 1, newDepth); value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); @@ -1257,7 +1248,7 @@ moves_loop: // When in check, search starts from here didLMR = false; } - // Step 17. Full depth search when LMR is skipped or fails high + // Step 16. Full depth search when LMR is skipped or fails high if (doFullDepthSearch) { value = -search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode); @@ -1285,12 +1276,12 @@ moves_loop: // When in check, search starts from here value = -search(pos, ss+1, -beta, -alpha, newDepth, false); } - // Step 18. Undo move + // Step 17. Undo move pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); - // Step 19. Check for a new best move + // Step 18. Check for a new best move // Finished searching the move. If a stop occurred, the return value of // the search cannot be trusted, and we return immediately without // updating best move, PV and TT. @@ -1367,7 +1358,7 @@ moves_loop: // When in check, search starts from here return VALUE_DRAW; */ - // Step 20. Check for mate and stalemate + // Step 19. Check for mate and stalemate // All legal moves have been searched and if there are no legal moves, it // must be a mate or a stalemate. If we are in a singular extension search then // return a fail low score. @@ -1534,6 +1525,10 @@ moves_loop: // When in check, search starts from here { assert(type_of(move) != ENPASSANT); // Due to !pos.advanced_pawn_push + // moveCount pruning + if (moveCount > 2) + continue; + futilityValue = futilityBase + PieceValue[EG][pos.piece_on(to_sq(move))]; if (futilityValue <= alpha) @@ -1550,7 +1545,7 @@ moves_loop: // When in check, search starts from here } // Do not search moves with negative SEE values - if ( !ss->inCheck && !pos.see_ge(move)) + if (!ss->inCheck && !pos.see_ge(move)) continue; // Speculative prefetch as early as possible @@ -1569,6 +1564,12 @@ moves_loop: // When in check, search starts from here [pos.moved_piece(move)] [to_sq(move)]; + if ( !captureOrPromotion + && moveCount >= abs(depth) + 1 + && (*contHist[0])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold + && (*contHist[1])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold) + continue; + // Make and search the move pos.do_move(move, st, givesCheck); value = -qsearch(pos, ss+1, -beta, -alpha, depth - 1);