X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=993fa853f47ce51d95c167ae3c951f70fce4f27b;hp=3f860ac5e5b9d073e93ab6f1f476a6a49e9c9eff;hb=b7ecdaada7e2690dd286c41d3a73463f06fb088f;hpb=b8c00efa2767ebf74545d2ba4bd344ef7c963319 diff --git a/src/search.cpp b/src/search.cpp index 3f860ac5..993fa853 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -365,7 +365,7 @@ 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"] ? - clamp(std::pow((Options["UCI_Elo"] - 1346.6) / 143.4, 1 / 0.806), 0.0, 20.0) : + Utility::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); @@ -433,7 +433,7 @@ void Thread::search() { if (rootDepth >= 4) { Value previousScore = rootMoves[pvIdx].previousScore; - delta = Value(21 + abs(previousScore) / 256); + delta = Value(21); alpha = std::max(previousScore - delta,-VALUE_INFINITE); beta = std::min(previousScore + delta, VALUE_INFINITE); @@ -538,7 +538,7 @@ void Thread::search() { { double fallingEval = (332 + 6 * (mainThread->previousScore - bestValue) + 6 * (mainThread->iterValue[iterIdx] - bestValue)) / 704.0; - fallingEval = clamp(fallingEval, 0.5, 1.5); + fallingEval = Utility::clamp(fallingEval, 0.5, 1.5); // If the bestMove is stable over several iterations, reduce time accordingly timeReduction = lastBestMoveDepth + 9 < completedDepth ? 1.94 : 0.91; @@ -819,14 +819,14 @@ namespace { ss->staticEval = eval = evaluate(pos) + bonus; } else - ss->staticEval = eval = -(ss-1)->staticEval + 2 * Eval::Tempo; + ss->staticEval = eval = -(ss-1)->staticEval + 2 * Tempo; tte->save(posKey, VALUE_NONE, ttPv, BOUND_NONE, DEPTH_NONE, MOVE_NONE, eval); } // Step 7. Razoring (~1 Elo) if ( !rootNode // The required rootNode PV handling is not available in qsearch - && depth < 2 + && depth == 1 && eval <= alpha - RazorMargin) return qsearch(pos, ss, alpha, beta); @@ -957,11 +957,12 @@ moves_loop: // When in check, search starts from here contHist, countermove, ss->killers, - depth > 12 && ttPv ? ss->ply : MAX_PLY); + depth > 12 ? ss->ply : MAX_PLY); value = bestValue; singularLMR = moveCountPruning = false; ttCapture = ttMove && pos.capture_or_promotion(ttMove); + bool formerPv = ttPv && !PvNode; // Mark this node as being searched ThreadHolding th(thisThread, posKey, ss->ply); @@ -1024,10 +1025,9 @@ moves_loop: // When in check, search starts from here if ( lmrDepth < 6 && !inCheck && ss->staticEval + 235 + 172 * lmrDepth <= alpha - && thisThread->mainHistory[us][from_to(move)] - + (*contHist[0])[movedPiece][to_sq(move)] + && (*contHist[0])[movedPiece][to_sq(move)] + (*contHist[1])[movedPiece][to_sq(move)] - + (*contHist[3])[movedPiece][to_sq(move)] < 25000) + + (*contHist[3])[movedPiece][to_sq(move)] < 27400) continue; // Prune moves with negative SEE (~20 Elo) @@ -1055,10 +1055,10 @@ moves_loop: // When in check, search starts from here && tte->depth() >= depth - 3 && pos.legal(move)) { - Value singularBeta = ttValue - (((ttPv && !PvNode) + 4) * depth) / 2; - Depth halfDepth = depth / 2; + Value singularBeta = ttValue - ((formerPv + 4) * depth) / 2; + Depth singularDepth = (depth - 1 + 3 * formerPv) / 2; ss->excludedMove = move; - value = search(pos, ss, singularBeta - 1, singularBeta, halfDepth, cutNode); + value = search(pos, ss, singularBeta - 1, singularBeta, singularDepth, cutNode); ss->excludedMove = MOVE_NONE; if (value < singularBeta) @@ -1144,13 +1144,16 @@ moves_loop: // When in check, search starts from here if (ttPv) r -= 2; + if (moveCountPruning && !formerPv) + r++; + // Decrease reduction if opponent's move count is high (~5 Elo) if ((ss-1)->moveCount > 14) r--; // Decrease reduction if ttMove has been singularly extended (~3 Elo) if (singularLMR) - r -= 2; + r -= 1 + formerPv; if (!captureOrPromotion) { @@ -1175,13 +1178,6 @@ moves_loop: // When in check, search starts from here + (*contHist[3])[movedPiece][to_sq(move)] - 4926; - // Reset statScore to zero if negative and most stats shows >= 0 - if ( ss->statScore < 0 - && (*contHist[0])[movedPiece][to_sq(move)] >= 0 - && (*contHist[1])[movedPiece][to_sq(move)] >= 0 - && thisThread->mainHistory[us][from_to(move)] >= 0) - ss->statScore = 0; - // Decrease/increase reduction by comparing opponent's stat score (~10 Elo) if (ss->statScore >= -102 && (ss-1)->statScore < -114) r--; @@ -1190,21 +1186,27 @@ moves_loop: // When in check, search starts from here r++; // Decrease/increase reduction for moves with a good/bad history (~30 Elo) - r -= ss->statScore / 16384; + r -= ss->statScore / 16434; } // Increase reduction for captures/promotions if late move and at low depth else if (depth < 8 && moveCount > 2) r++; - Depth d = clamp(newDepth - r, 1, newDepth); + Depth d = Utility::clamp(newDepth - r, 1, newDepth); value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); - doFullDepthSearch = (value > alpha && d != newDepth), didLMR = true; + doFullDepthSearch = value > alpha && d != newDepth; + + didLMR = true; } else - doFullDepthSearch = !PvNode || moveCount > 1, didLMR = false; + { + doFullDepthSearch = !PvNode || moveCount > 1; + + didLMR = false; + } // Step 17. Full depth search when LMR is skipped or fails high if (doFullDepthSearch) @@ -1339,7 +1341,7 @@ moves_loop: // When in check, search starts from here if (PvNode) bestValue = std::min(bestValue, maxValue); - if (!excludedMove) + if (!excludedMove && !(rootNode && thisThread->pvIdx)) tte->save(posKey, value_to_tt(bestValue, ss->ply), ttPv, bestValue >= beta ? BOUND_LOWER : PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, @@ -1434,13 +1436,13 @@ moves_loop: // When in check, search starts from here else ss->staticEval = bestValue = (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) - : -(ss-1)->staticEval + 2 * Eval::Tempo; + : -(ss-1)->staticEval + 2 * Tempo; // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) { if (!ttHit) - tte->save(posKey, value_to_tt(bestValue, ss->ply), pvHit, BOUND_LOWER, + tte->save(posKey, value_to_tt(bestValue, ss->ply), false, BOUND_LOWER, DEPTH_NONE, MOVE_NONE, ss->staticEval); return bestValue; @@ -1667,7 +1669,7 @@ moves_loop: // When in check, search starts from here // update_continuation_histories() updates histories of the move pairs formed - // by moves at ply -1, -2, and -4 with current move. + // by moves at ply -1, -2, -4, and -6 with current move. void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) {