X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d659fab6a1654f6bce5b1ed4d26e120d3962cb3a;hp=3dbcb526dbff7187014d5d477df9ae7792f03f04;hb=419c5b69caa2918f9cb74d6ec71d790bc276b424;hpb=55745f410547f22b1edce873b38cc3ce5f3ace5f diff --git a/src/search.cpp b/src/search.cpp index 3dbcb526..d659fab6 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() { @@ -844,7 +838,7 @@ namespace { // If we are pondering or in infinite search, we shouldn't print the // best move before we are told to do so. - if (PonderSearch || InfiniteSearch) + if (!AbortSearch && (PonderSearch || InfiniteSearch)) wait_for_stop_or_ponderhit(); else // Print final search statistics @@ -961,6 +955,8 @@ namespace { { // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. + bool doFullDepthSearch = true; + if ( depth >= 3*OnePly // FIXME was newDepth && !dangerous && !captureOrPromotion @@ -971,13 +967,11 @@ namespace { { ss[0].reduction = Depth(int(floor(red * int(OnePly)))); value = -search(pos, ss, -alpha, newDepth-ss[0].reduction, 1, true, 0); + doFullDepthSearch = (value > alpha); } - else - value = alpha + 1; // Just to trigger next condition - } else - value = alpha + 1; // Just to trigger next condition + } - if (value > alpha) + if (doFullDepthSearch) { value = -search(pos, ss, -alpha, newDepth, 1, true, 0); @@ -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); @@ -1217,6 +1207,8 @@ namespace { { // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. + bool doFullDepthSearch = true; + if ( depth >= 3*OnePly && !dangerous && !captureOrPromotion @@ -1228,14 +1220,11 @@ namespace { { ss[ply].reduction = Depth(int(floor(red * int(OnePly)))); value = -search(pos, ss, -alpha, newDepth-ss[ply].reduction, ply+1, true, threadID); + doFullDepthSearch = (value > alpha); } - else - value = alpha + 1; // Just to trigger next condition } - else - value = alpha + 1; // Just to trigger next condition - if (value > alpha) // Go with full depth non-pv search + if (doFullDepthSearch) // Go with full depth non-pv search { ss[ply].reduction = Depth(0); value = -search(pos, ss, -alpha, newDepth, ply+1, true, threadID); @@ -1338,11 +1327,11 @@ 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 +1344,9 @@ 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 +1369,25 @@ 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 +1440,14 @@ 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; @@ -1551,6 +1540,8 @@ namespace { // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. + bool doFullDepthSearch = true; + if ( depth >= 3*OnePly && !dangerous && !captureOrPromotion @@ -1563,14 +1554,11 @@ namespace { { ss[ply].reduction = Depth(int(floor(red * int(OnePly)))); value = -search(pos, ss, -(beta-1), newDepth-ss[ply].reduction, ply+1, true, threadID); + doFullDepthSearch = (value >= beta); } - else - value = beta; // Just to trigger next condition } - else - value = beta; // Just to trigger next condition - if (value >= beta) // Go with full depth non-pv search + if (doFullDepthSearch) // Go with full depth non-pv search { ss[ply].reduction = Depth(0); value = -search(pos, ss, -(beta-1), newDepth, ply+1, true, threadID); @@ -1664,12 +1652,9 @@ 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 +1669,6 @@ namespace { } isCheck = pos.is_check(); - ei.futilityMargin = Value(0); // Manually initialize futilityMargin // Evaluate the position statically if (isCheck) @@ -1831,7 +1815,6 @@ 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 +1848,6 @@ 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) @@ -1892,6 +1869,8 @@ namespace { // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. + bool doFullDepthSearch = true; + if ( !dangerous && !captureOrPromotion && !move_is_castle(move) @@ -1902,14 +1881,11 @@ namespace { { ss[sp->ply].reduction = Depth(int(floor(red * int(OnePly)))); value = -search(pos, ss, -(sp->beta-1), newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID); + doFullDepthSearch = (value >= sp->beta); } - else - value = sp->beta; // Just to trigger next condition } - else - value = sp->beta; // Just to trigger next condition - if (value >= sp->beta) // Go with full depth non-pv search + if (doFullDepthSearch) // Go with full depth non-pv search { ss[sp->ply].reduction = Depth(0); value = -search(pos, ss, -(sp->beta - 1), newDepth, sp->ply+1, true, threadID); @@ -2003,6 +1979,8 @@ namespace { // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. + bool doFullDepthSearch = true; + if ( !dangerous && !captureOrPromotion && !move_is_castle(move) @@ -2011,24 +1989,23 @@ namespace { double red = 0.5 + ln(moveCount) * ln(sp->depth / 2) / 6.0; if (red >= 1.0) { + Value localAlpha = sp->alpha; ss[sp->ply].reduction = Depth(int(floor(red * int(OnePly)))); - value = -search(pos, ss, -sp->alpha, newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID); + value = -search(pos, ss, -localAlpha, newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID); + doFullDepthSearch = (value > localAlpha); } - else - value = sp->alpha + 1; // Just to trigger next condition } - else - value = sp->alpha + 1; // Just to trigger next condition - if (value > sp->alpha) // Go with full depth non-pv search + if (doFullDepthSearch) // Go with full depth non-pv search { + Value localAlpha = sp->alpha; ss[sp->ply].reduction = Depth(0); - value = -search(pos, ss, -sp->alpha, newDepth, sp->ply+1, true, threadID); + value = -search(pos, ss, -localAlpha, newDepth, sp->ply+1, true, threadID); - if (value > sp->alpha && value < sp->beta) + if (value > localAlpha && value < sp->beta) { // When the search fails high at ply 1 while searching the first - // move at the root, set the flag failHighPly1. This is used for + // move at the root, set the flag failHighPly1. This is used for // time managment: We don't want to stop the search early in // such cases, because resolving the fail high at ply 1 could // result in a big drop in score at the root.