X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=64cdf1c4e5fac5f27d679e7ed4c2ad865c961a19;hp=ea9240e56e5664d2c0dafe7509fac4cc783939a2;hb=72e1e9b986fc4c656c3a3db24e5504e3edbb63cc;hpb=638f3d31cc9a61ce3df2b685fef96f15e0afb940 diff --git a/src/search.cpp b/src/search.cpp index ea9240e5..64cdf1c4 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -172,9 +172,9 @@ namespace { // best move from the previous iteration, Problem is set back to false. const Value NoProblemMargin = Value(0x14); - // Null move margin. A null move search will not be done if the approximate + // Null move margin. A null move search will not be done if the static // evaluation of the position is more than NullMoveMargin below beta. - const Value NullMoveMargin = Value(0x300); + const Value NullMoveMargin = Value(0x200); // If the TT move is at least SingleReplyMargin better then the // remaining ones we will extend it. @@ -190,13 +190,6 @@ namespace { // Depth limit for razoring const Depth RazorDepth = 4 * OnePly; - // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply - const Value RazorMargins[6] = { Value(0x180), Value(0x300), Value(0x300), Value(0x3C0), Value(0x3C0), Value(0x3C0) }; - - // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply - const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) }; - - /// Variables initialized by UCI options // Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV nodes @@ -659,6 +652,7 @@ void SearchStack::init(int ply) { pv[ply] = pv[ply + 1] = MOVE_NONE; currentMove = threatMove = MOVE_NONE; reduction = Depth(0); + eval = VALUE_NONE; } void SearchStack::initKillers() { @@ -1104,7 +1098,6 @@ namespace { assert(threadID >= 0 && threadID < ActiveThreads); Move movesSearched[256]; - EvalInfo ei; StateInfo st; const TTEntry* tte; Move ttMove, move; @@ -1125,12 +1118,9 @@ namespace { if (AbortSearch || thread_should_stop(threadID)) return Value(0); - if (pos.is_draw()) + if (pos.is_draw() || ply >= PLY_MAX - 1) return VALUE_DRAW; - if (ply >= PLY_MAX - 1) - return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID); - // Mate distance pruning oldAlpha = alpha; alpha = Max(value_mated_in(ply), alpha); @@ -1338,11 +1328,11 @@ namespace { const TTEntry* tte; Move ttMove, move; Depth ext, newDepth; - Value staticValue, nullValue, value, futilityValue, futilityValueScaled; + Value bestValue, staticValue, nullValue, value, futilityValue, futilityValueScaled; bool isCheck, useFutilityPruning, singleEvasion, moveIsCheck, captureOrPromotion, dangerous; bool mateThreat = false; int moveCount = 0; - Value bestValue = -VALUE_INFINITE; + futilityValue = staticValue = bestValue = -VALUE_INFINITE; if (depth < OnePly) return qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID); @@ -1355,12 +1345,9 @@ namespace { if (AbortSearch || thread_should_stop(threadID)) return Value(0); - if (pos.is_draw()) + if (pos.is_draw() || ply >= PLY_MAX - 1) return VALUE_DRAW; - if (ply >= PLY_MAX - 1) - return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID); - // Mate distance pruning if (value_mated_in(ply) >= beta) return beta; @@ -1383,23 +1370,25 @@ namespace { } isCheck = pos.is_check(); - ei.futilityMargin = Value(0); // Manually initialize futilityMargin - - // Evaluate the position statically - if (isCheck) - staticValue = quick_evaluate(pos); - else if (tte && (tte->type() & VALUE_TYPE_EVAL)) - staticValue = value_from_tt(tte->value(), ply); - else - staticValue = evaluate(pos, ei, threadID); // Calculate depth dependant futility pruning parameters const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8)); const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2); - // Enhance score accuracy with TT value if possible - futilityValue = staticValue + FutilityValueMargin; - staticValue = refine_eval(tte, staticValue, ply); + // Evaluate the position statically + if (isCheck) + ss[ply].eval = VALUE_NONE; + else + { + if (tte && (tte->type() & VALUE_TYPE_EVAL)) + staticValue = value_from_tt(tte->value(), ply); + else + staticValue = evaluate(pos, ei, threadID); + + ss[ply].eval = staticValue; + futilityValue = staticValue + FutilityValueMargin; + staticValue = refine_eval(tte, staticValue, ply); // Enhance accuracy with TT value if possible + } // Null move search if ( allowNullmove @@ -1452,13 +1441,14 @@ namespace { } // Null move search not allowed, try razoring else if ( !value_is_mate(beta) + && !isCheck && depth < RazorDepth - && staticValue < beta - RazorApprMargins[int(depth) - 2] + && staticValue < beta - (NullMoveMargin + 16 * depth) && ss[ply - 1].currentMove != MOVE_NULL && ttMove == MOVE_NONE && !pos.has_pawn_on_7th(pos.side_to_move())) { - Value rbeta = beta - RazorMargins[int(depth) - 2]; + Value rbeta = beta - (NullMoveMargin + 16 * depth); Value v = qsearch(pos, ss, rbeta-1, rbeta, Depth(0), ply, threadID); if (v < rbeta) return v; @@ -1664,12 +1654,9 @@ namespace { if (AbortSearch || thread_should_stop(threadID)) return Value(0); - if (pos.is_draw()) + if (pos.is_draw() || ply >= PLY_MAX - 1) return VALUE_DRAW; - if (ply >= PLY_MAX - 1) - return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID); - // Transposition table lookup. At PV nodes, we don't use the TT for // pruning, but only for move ordering. tte = TT.retrieve(pos.get_key()); @@ -1684,7 +1671,6 @@ namespace { } isCheck = pos.is_check(); - ei.futilityMargin = Value(0); // Manually initialize futilityMargin // Evaluate the position statically if (isCheck) @@ -1831,7 +1817,6 @@ namespace { && !isCheck; const int FutilityMoveCountMargin = 3 + (1 << (3 * int(sp->depth) / 8)); - const int FutilityValueMargin = 112 * bitScanReverse32(int(sp->depth) * int(sp->depth) / 2); while ( sp->bestValue < sp->beta && !thread_should_stop(threadID) @@ -1865,12 +1850,6 @@ namespace { continue; // Value based pruning - if (sp->futilityValue == VALUE_NONE) - { - EvalInfo ei; - sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin; - } - Value futilityValueScaled = sp->futilityValue - moveCount * IncrementalFutilityMargin; if (futilityValueScaled < sp->beta)