X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=21756824b815bfa58f37f1f4f948277466dab7a8;hp=c0a982363403ccae483d2fc5a00796e2323a06f6;hb=ecd07e51d0f03ccd3e41e5634518b299989254dd;hpb=52ae0efccffcce7f095cc4bae7bf90fe7a3b467b;ds=sidebyside diff --git a/src/search.cpp b/src/search.cpp index c0a98236..21756824 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -63,13 +63,12 @@ namespace { inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); } // Futility lookup tables (initialized at startup) and their access functions - Value FutilityMargins[16][64]; // [depth][moveNumber] + Value FutilityMargins[14][64]; // [depth][moveNumber] int FutilityMoveCounts[2][32]; // [improving][depth] inline Value futility_margin(Depth d, int mn) { - - return d < 7 * ONE_PLY ? FutilityMargins[std::max(int(d), 1)][std::min(mn, 63)] - : 2 * VALUE_INFINITE; + assert(DEPTH_ZERO <= d && d < 7 * ONE_PLY); + return FutilityMargins[d][std::min(mn, 63)]; } // Reduction lookup tables (initialized at startup) and their access function @@ -85,7 +84,6 @@ namespace { double BestMoveChanges; Value DrawValue[COLOR_NB]; HistoryStats History; - GainsStats Gains; CountermovesStats Countermoves; template @@ -147,8 +145,8 @@ void Search::init() { } // Init futility margins array - for (d = 1; d < 16; ++d) for (mc = 0; mc < 64; ++mc) - FutilityMargins[d][mc] = Value(112 * int(2.9 * log(double(d))) - 8 * mc + 45); + for (d = 0; d < 14; ++d) for (mc = 0; mc < 64; ++mc) + FutilityMargins[d][mc] = Value(112 * int(2.9 * log(d >= 1 ? double(d) : 1.0)) - 8 * mc + 45); // Init futility move count array for (d = 0; d < 32; ++d) @@ -301,7 +299,6 @@ namespace { Value bestValue, alpha, beta, delta; std::memset(ss-2, 0, 5 * sizeof(Stack)); - (ss-1)->currentMove = MOVE_NULL; // Hack to skip update gains depth = 0; BestMoveChanges = 0; @@ -310,7 +307,6 @@ namespace { TT.new_search(); History.clear(); - Gains.clear(); Countermoves.clear(); PVSize = Options["MultiPV"]; @@ -499,7 +495,7 @@ namespace { Move ttMove, move, excludedMove, bestMove, threatMove; Depth ext, newDepth; Value bestValue, value, ttValue; - Value eval, nullValue, futilityValue; + Value eval, nullValue; bool inCheck, givesCheck, pvMove, singularExtensionNode, improving; bool captureOrPromotion, dangerous, doFullDepthSearch; int moveCount, quietCount; @@ -591,16 +587,15 @@ namespace { // Step 5. Evaluate the position statically and update parent's gain statistics if (inCheck) { - ss->staticEval = ss->evalMargin = eval = VALUE_NONE; + ss->staticEval = eval = VALUE_NONE; goto moves_loop; } else if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE - ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) - eval = ss->staticEval = evaluate(pos, ss->evalMargin); + if ((ss->staticEval = eval = tte->eval_value()) == VALUE_NONE) + eval = ss->staticEval = evaluate(pos); // Can ttValue be used as a better position evaluation? if (ttValue != VALUE_NONE) @@ -609,21 +604,8 @@ namespace { } else { - eval = ss->staticEval = evaluate(pos, ss->evalMargin); - TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, - ss->staticEval, ss->evalMargin); - } - - // Update gain for the parent non-capture move given the static position - // evaluation before and after the move. - if ( !pos.captured_piece_type() - && ss->staticEval != VALUE_NONE - && (ss-1)->staticEval != VALUE_NONE - && (move = (ss-1)->currentMove) != MOVE_NULL - && type_of(move) == NORMAL) - { - Square to = to_sq(move); - Gains.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); + eval = ss->staticEval = evaluate(pos); + TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval); } // Step 6. Razoring (skipped when in check) @@ -642,12 +624,10 @@ namespace { return v; } - // Step 7. Static null move pruning (skipped when in check) - // We're betting that the opponent doesn't have a move that will reduce - // the score by more than futility_margin(depth) if we do a null move. + // Step 7. post-Futility pruning (skipped when in check) if ( !PvNode && !ss->skipNullMove - && depth < 4 * ONE_PLY + && depth < 7 * ONE_PLY && eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta && abs(beta) < VALUE_MATE_IN_MAX_PLY && abs(eval) < VALUE_KNOWN_WIN @@ -854,13 +834,13 @@ moves_loop: // When in check and at SpNode search starts from here // Update current move (this must be done after singular extension search) newDepth = depth - ONE_PLY + ext; + Depth predictedDepth = newDepth - reduction(improving, depth, moveCount); // Step 13. Futility pruning (is omitted in PV nodes) if ( !PvNode && !captureOrPromotion && !inCheck && !dangerous - /* && move != ttMove Already implicit in the next condition */ && bestValue > VALUE_MATED_IN_MAX_PLY) { // Move count based pruning @@ -874,26 +854,6 @@ moves_loop: // When in check and at SpNode search starts from here continue; } - // Value based pruning - // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth, - // but fixing this made program slightly weaker. - Depth predictedDepth = newDepth - reduction(improving, depth, moveCount); - futilityValue = ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount) - + Gains[pos.moved_piece(move)][to_sq(move)]; - - if (futilityValue < beta) - { - bestValue = std::max(bestValue, futilityValue); - - if (SpNode) - { - splitPoint->mutex.lock(); - if (bestValue > splitPoint->bestValue) - splitPoint->bestValue = bestValue; - } - continue; - } - // Prune moves with negative SEE at low depths if ( predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < 0) @@ -1079,7 +1039,7 @@ moves_loop: // When in check and at SpNode search starts from here TT.store(posKey, value_to_tt(bestValue, ss->ply), bestValue >= beta ? BOUND_LOWER : PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, - depth, bestMove, ss->staticEval, ss->evalMargin); + depth, bestMove, ss->staticEval); // Quiet best move: update killers, history and countermoves if ( bestValue >= beta @@ -1172,7 +1132,7 @@ moves_loop: // When in check and at SpNode search starts from here // Evaluate the position statically if (InCheck) { - ss->staticEval = ss->evalMargin = VALUE_NONE; + ss->staticEval = VALUE_NONE; bestValue = futilityBase = -VALUE_INFINITE; } else @@ -1180,9 +1140,8 @@ moves_loop: // When in check and at SpNode search starts from here if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE - ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) - ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); + if ((ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE) + ss->staticEval = bestValue = evaluate(pos); // Can ttValue be used as a better position evaluation? if (ttValue != VALUE_NONE) @@ -1190,14 +1149,14 @@ moves_loop: // When in check and at SpNode search starts from here bestValue = ttValue; } else - ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); + ss->staticEval = bestValue = evaluate(pos); // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) { if (!tte) TT.store(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER, - DEPTH_NONE, MOVE_NONE, ss->staticEval, ss->evalMargin); + DEPTH_NONE, MOVE_NONE, ss->staticEval); return bestValue; } @@ -1205,7 +1164,7 @@ moves_loop: // When in check and at SpNode search starts from here if (PvNode && bestValue > alpha) alpha = bestValue; - futilityBase = bestValue + ss->evalMargin + Value(128); + futilityBase = bestValue + Value(128); } // Initialize a MovePicker object for the current position, and prepare @@ -1294,7 +1253,7 @@ moves_loop: // When in check and at SpNode search starts from here else // Fail high { TT.store(posKey, value_to_tt(value, ss->ply), BOUND_LOWER, - ttDepth, move, ss->staticEval, ss->evalMargin); + ttDepth, move, ss->staticEval); return value; } @@ -1309,7 +1268,7 @@ moves_loop: // When in check and at SpNode search starts from here TT.store(posKey, value_to_tt(bestValue, ss->ply), PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER, - ttDepth, bestMove, ss->staticEval, ss->evalMargin); + ttDepth, bestMove, ss->staticEval); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1572,7 +1531,7 @@ void RootMove::insert_pv_in_tt(Position& pos) { tte = TT.probe(pos.key()); if (!tte || tte->move() != pv[ply]) // Don't overwrite correct entries - TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], VALUE_NONE, VALUE_NONE); + TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], VALUE_NONE); assert(MoveList(pos).contains(pv[ply]));