X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=8639393c16567ed03f2db3c3b74da90e583953b1;hp=515cc6ceae163e234b9158a8ef25322c1bb44d72;hb=b2961aded6cd2807a8c4899e090e28fcb2161310;hpb=43682d08f7a85a997ff71fdb68ee6392c5d49b21 diff --git a/src/search.cpp b/src/search.cpp index 515cc6ce..8639393c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -69,7 +69,9 @@ namespace { // Razor and futility margins const int RazorMargin1 = 590; const int RazorMargin2 = 604; - Value futility_margin(Depth d) { return Value(150 * d / ONE_PLY); } + Value futility_margin(Depth d, bool improving) { + return Value((175 - 50 * improving) * d / ONE_PLY); + } // Futility and reductions lookup tables, initialized at startup int FutilityMoveCounts[2][16]; // [improving][depth] @@ -99,7 +101,7 @@ namespace { template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode, bool skipEarlyPruning); - template + template Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth = DEPTH_ZERO); Value value_to_tt(Value v, int ply); @@ -349,10 +351,7 @@ void Thread::search() { ct = Options["Contempt"] * PawnValueEg / 100; // From centipawns // Adjust contempt based on current bestValue (dynamic contempt) - int sign = (bestValue > 0) - (bestValue < 0); - ct += bestValue > 500 ? 70 : - bestValue < -500 ? -70 : - bestValue / 10 + sign * int(std::round(3.22 * log(1 + abs(bestValue)))); + ct += int(std::round(48 * atan(float(bestValue) / 128))); Eval::Contempt = (us == WHITE ? make_score(ct, ct / 2) : -make_score(ct, ct / 2)); @@ -655,6 +654,7 @@ namespace { if (inCheck) { ss->staticEval = eval = VALUE_NONE; + improving = true; goto moves_loop; } else if (ttHit) @@ -678,6 +678,9 @@ namespace { ss->staticEval, TT.generation()); } + improving = ss->staticEval >= (ss-2)->staticEval + ||(ss-2)->staticEval == VALUE_NONE; + if (skipEarlyPruning || !pos.non_pawn_material(pos.side_to_move())) goto moves_loop; @@ -687,12 +690,12 @@ namespace { { if ( depth == ONE_PLY && eval + RazorMargin1 <= alpha) - return qsearch(pos, ss, alpha, alpha+1); + return qsearch(pos, ss, alpha, alpha+1); else if (eval + RazorMargin2 <= alpha) { Value ralpha = alpha - RazorMargin2; - Value v = qsearch(pos, ss, ralpha, ralpha+1); + Value v = qsearch(pos, ss, ralpha, ralpha+1); if (v <= ralpha) return v; @@ -702,7 +705,7 @@ namespace { // Step 8. Futility pruning: child node (skipped when in check) if ( !rootNode && depth < 7 * ONE_PLY - && eval - futility_margin(depth) >= beta + && eval - futility_margin(depth, improving) >= beta && eval < VALUE_KNOWN_WIN) // Do not return unproven wins return eval; @@ -721,7 +724,7 @@ namespace { ss->contHistory = thisThread->contHistory[NO_PIECE][0].get(); pos.do_null_move(st); - Value nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1) + Value nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1) : - search(pos, ss+1, -beta, -beta+1, depth-R, !cutNode, true); pos.undo_null_move(); @@ -739,7 +742,7 @@ namespace { thisThread->nmp_ply = ss->ply + 3 * (depth-R) / 4; thisThread->nmp_odd = ss->ply % 2; - Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta) + Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta) : search(pos, ss, beta-1, beta, depth-R, false, true); thisThread->nmp_odd = thisThread->nmp_ply = 0; @@ -761,6 +764,7 @@ namespace { Value rbeta = std::min(beta + 200, VALUE_INFINITE); MovePicker mp(pos, ttMove, rbeta - ss->staticEval, &thisThread->captureHistory); int probCutCount = 0; + while ( (move = mp.next_move()) != MOVE_NONE && probCutCount < depth / ONE_PLY - 3) if (pos.legal(move)) @@ -774,15 +778,11 @@ namespace { pos.do_move(move, st); - // Perform a preliminary search at depth 1 to verify that the move holds. - // We will only do this search if the depth is not 5, thus avoiding two - // searches at depth 1 in a row. - if (depth > 5 * ONE_PLY) - value = -search(pos, ss+1, -rbeta, -rbeta+1, ONE_PLY, !cutNode, true); + // Perform a preliminary qsearch to verify that the move holds + value = -qsearch(pos, ss+1, -rbeta, -rbeta+1); - // If the first search was skipped or was performed and held, perform - // the regular search. - if (depth == 5 * ONE_PLY || value >= rbeta) + // If the qsearch held perform the regular search + if (value >= rbeta) value = -search(pos, ss+1, -rbeta, -rbeta+1, depth - 4 * ONE_PLY, !cutNode, false); pos.undo_move(move); @@ -812,9 +812,6 @@ moves_loop: // When in check, search starts from here MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &thisThread->captureHistory, contHist, countermove, ss->killers); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc - improving = ss->staticEval >= (ss-2)->staticEval - /* || ss->staticEval == VALUE_NONE Already implicit in the previous condition */ - ||(ss-2)->staticEval == VALUE_NONE; singularExtensionNode = !rootNode && depth >= 8 * ONE_PLY @@ -1012,9 +1009,7 @@ moves_loop: // When in check, search starts from here // Step 17. Full depth search when LMR is skipped or fails high if (doFullDepthSearch) - value = newDepth < ONE_PLY ? - givesCheck ? -qsearch(pos, ss+1, -(alpha+1), -alpha) - : -qsearch(pos, ss+1, -(alpha+1), -alpha) + value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha) : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode, false); // For PV nodes only, do a full PV search on the first move or after a fail @@ -1025,9 +1020,7 @@ moves_loop: // When in check, search starts from here (ss+1)->pv = pv; (ss+1)->pv[0] = MOVE_NONE; - value = newDepth < ONE_PLY ? - givesCheck ? -qsearch(pos, ss+1, -beta, -alpha) - : -qsearch(pos, ss+1, -beta, -alpha) + value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha) : - search(pos, ss+1, -beta, -alpha, newDepth, false, false); } @@ -1157,17 +1150,16 @@ moves_loop: // When in check, search starts from here // qsearch() is the quiescence search function, which is called by the main // search function with depth zero, or recursively with depth less than ONE_PLY. - - template + template Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) { const bool PvNode = NT == PV; + const bool InCheck = bool(pos.checkers()); assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); assert(PvNode || (alpha == beta - 1)); assert(depth <= DEPTH_ZERO); assert(depth / ONE_PLY * ONE_PLY == depth); - assert(InCheck == bool(pos.checkers())); Move pv[MAX_PLY+1]; StateInfo st; @@ -1319,8 +1311,7 @@ moves_loop: // When in check, search starts from here // Make and search the move pos.do_move(move, st, givesCheck); - value = givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY) - : -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY); + value = -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY); pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);