X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=b6029e0c71f4dcd3506092a0695b22a0c0446d4c;hp=e5063b2453b01ff490f167993ddd3099f2a60a2b;hb=c52da3b806b74ba5ab5249784d39da8fec3c7465;hpb=975d5e9c6444b3289cb8688d68d17ec9ed2a2285 diff --git a/src/search.cpp b/src/search.cpp index e5063b24..b6029e0c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -176,6 +176,9 @@ namespace { // and near frontier nodes. const Value FutilityMarginQS = Value(0x80); + // Each move futility margin is decreased + const Value IncrementalFutilityMargin = Value(0xA); + // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply const Value FutilityMargins[12] = { Value(0x100), Value(0x120), Value(0x200), Value(0x220), Value(0x250), Value(0x270), // 4 ply 4.5 ply 5 ply 5.5 ply 6 ply 6.5 ply @@ -310,7 +313,7 @@ namespace { Value *alpha, Value *beta, Value *bestValue, const Value futilityValue, const Value approximateValue, Depth depth, int *moves, - MovePicker *mp, Bitboard dcCandidates, int master, bool pvNode); + MovePicker *mp, int master, bool pvNode); void wake_sleeping_threads(); #if !defined(_MSC_VER) @@ -333,25 +336,25 @@ namespace { int perft(Position& pos, Depth depth) { Move move; - MovePicker mp = MovePicker(pos, MOVE_NONE, depth, H); - Bitboard dcCandidates = pos.discovered_check_candidates(pos.side_to_move()); int sum = 0; + MovePicker mp = MovePicker(pos, MOVE_NONE, depth, H); // If we are at the last ply we don't need to do and undo // the moves, just to count them. if (depth <= OnePly) // Replace with '<' to test also qsearch { - while ((move = mp.get_next_move()) != MOVE_NONE) sum++; + while (mp.get_next_move()) sum++; return sum; } // Loop through all legal moves + CheckInfo ci(pos); while ((move = mp.get_next_move()) != MOVE_NONE) { - StateInfo st; - pos.do_move(move, st, dcCandidates); - sum += perft(pos, depth - OnePly); - pos.undo_move(move); + StateInfo st; + pos.do_move(move, st, ci, pos.move_is_check(move, ci)); + sum += perft(pos, depth - OnePly); + pos.undo_move(move); } return sum; } @@ -862,7 +865,7 @@ namespace { Value oldAlpha = alpha; Value value; - Bitboard dcCandidates = pos.discovered_check_candidates(pos.side_to_move()); + CheckInfo ci(pos); // Loop through all the moves in the root move list for (int i = 0; i < rml.move_count() && !AbortSearch; i++) @@ -898,13 +901,14 @@ namespace { << " currmovenumber " << i + 1 << std::endl; // Decide search depth for this move + bool moveIsCheck = pos.move_is_check(move); bool captureOrPromotion = pos.move_is_capture_or_promotion(move); bool dangerous; - ext = extension(pos, move, true, captureOrPromotion, pos.move_is_check(move), false, false, &dangerous); + ext = extension(pos, move, true, captureOrPromotion, moveIsCheck, false, false, &dangerous); newDepth = (Iteration - 2) * OnePly + ext + InitialDepth; // Make the move, and search it - pos.do_move(move, st, dcCandidates); + pos.do_move(move, st, ci, moveIsCheck); if (i < MultiPV) { @@ -1065,7 +1069,6 @@ namespace { Move movesSearched[256]; EvalInfo ei; StateInfo st; - Bitboard dcCandidates; const TTEntry* tte; Move ttMove, move; Depth ext, newDepth; @@ -1115,7 +1118,6 @@ namespace { isCheck = pos.is_check(); mateThreat = pos.has_mate_threat(opposite_color(pos.side_to_move())); CheckInfo ci(pos); - dcCandidates = ci.dcCandidates; MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]); // Loop through all legal moves until no moves remain or a beta cutoff @@ -1137,7 +1139,7 @@ namespace { newDepth = depth - OnePly + ext; // Make and search the move - pos.do_move(move, st, dcCandidates); + pos.do_move(move, st, ci, moveIsCheck); if (moveCount == 1) // The first move in list is the PV value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID); @@ -1210,8 +1212,8 @@ namespace { && idle_thread_exists(threadID) && !AbortSearch && !thread_should_stop(threadID) - && split(pos, ss, ply, &alpha, &beta, &bestValue, VALUE_NONE, VALUE_NONE, depth, - &moveCount, &mp, dcCandidates, threadID, true)) + && split(pos, ss, ply, &alpha, &beta, &bestValue, VALUE_NONE, VALUE_NONE, + depth, &moveCount, &mp, threadID, true)) break; } @@ -1258,11 +1260,10 @@ namespace { Move movesSearched[256]; EvalInfo ei; StateInfo st; - Bitboard dcCandidates; const TTEntry* tte; Move ttMove, move; Depth ext, newDepth; - Value approximateEval, nullValue, value, futilityValue; + Value approximateEval, nullValue, value, futilityValue, futilityValueScaled; bool isCheck, useFutilityPruning, singleReply, moveIsCheck, captureOrPromotion, dangerous; bool mateThreat = false; int moveCount = 0; @@ -1316,7 +1317,13 @@ namespace { ss[ply].currentMove = MOVE_NULL; pos.do_null_move(st); - int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction + + // Null move dynamic reduction based on depth + int R = (depth >= 5 * OnePly ? 4 : 3); + + // Null move dynamic reduction based on value + if (approximateEval - beta > PawnValueMidgame) + R++; nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID); @@ -1356,8 +1363,9 @@ namespace { && ttMove == MOVE_NONE && !pos.has_pawn_on_7th(pos.side_to_move())) { - Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID); - if (v < beta - RazorMargins[int(depth) - 2]) + Value rbeta = beta - RazorMargins[int(depth) - 2]; + Value v = qsearch(pos, ss, rbeta-1, rbeta, Depth(0), ply, threadID); + if (v < rbeta) return v; } @@ -1373,7 +1381,6 @@ namespace { // to search all moves. MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]); CheckInfo ci(pos); - dcCandidates = ci.dcCandidates; futilityValue = VALUE_NONE; useFutilityPruning = depth < SelectiveDepth && !isCheck; @@ -1381,6 +1388,9 @@ namespace { if (tte && (tte->type() & VALUE_TYPE_EVAL)) futilityValue = value_from_tt(tte->value(), ply) + FutilityMargins[int(depth) - 2]; + // Move count pruning limit + const int MCLimit = 3 + (1 << (3*int(depth)/8)); + // Loop through all legal moves until no moves remain or a beta cutoff // occurs. while ( bestValue < beta @@ -1402,10 +1412,58 @@ namespace { // Futility pruning if ( useFutilityPruning && !dangerous - && !captureOrPromotion) + && !captureOrPromotion + && move != ttMove) { + //std::cout << std::endl; + //for (int d = 2; d < 14; d++) + // std::cout << d << ", " << 64*(1+bitScanReverse32(d*d)) << std::endl; + + //std::cout << std::endl; +/* + 64*(1+bitScanReverse32(d*d)) + + 2 -> 256 - 256 + 3 -> 288 - 320 + 4 -> 512 - 384 + 5 -> 544 - 384 + 6 -> 592 - 448 + 7 -> 624 - 448 + 8 -> 672 - 512 + 9 -> 704 - 512 + 10 -> 832 - 512 + 11 -> 864 - 512 + 12 -> 928 - 576 + 13 -> 960 - 576 + + 300 + 2*(1 << (3*d/4)) + + 2 -> 256 - 304 + 3 -> 288 - 308 + 4 -> 512 - 316 + 5 -> 544 - 316 + 6 -> 592 - 332 + 7 -> 624 - 364 + 8 -> 672 - 428 + 9 -> 704 - 428 + 10 -> 832 - 556 + 11 -> 864 - 812 + 12 -> 928 - 1324 + 13 -> 960 - 1324 + + + 3 + (1 << (3*int(depth)/8)) + + 1 * onePly - > moveCount >= 4 + 2 * onePly - > moveCount >= 5 + 3 * onePly - > moveCount >= 7 + 4 * onePly - > moveCount >= 11 + 5 * onePly - > moveCount >= 11 + 6 * onePly - > moveCount >= 19 + 7 * onePly - > moveCount >= 35 +*/ // History pruning. See ok_to_prune() definition - if ( moveCount >= 2 + int(depth) + if ( moveCount >= MCLimit && ok_to_prune(pos, move, ss[ply].threatMove, depth) && bestValue > value_mated_in(PLY_MAX)) continue; @@ -1415,19 +1473,22 @@ namespace { { if (futilityValue == VALUE_NONE) futilityValue = evaluate(pos, ei, threadID) - + FutilityMargins[int(depth) - 2]; + + 64*(1+bitScanReverse32(int(depth) * int(depth))) + + 4*IncrementalFutilityMargin; + + futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin; - if (futilityValue < beta) + if (futilityValueScaled < beta) { - if (futilityValue > bestValue) - bestValue = futilityValue; + if (futilityValueScaled > bestValue) + bestValue = futilityValueScaled; continue; } } } // Make and search the move - pos.do_move(move, st, dcCandidates); + pos.do_move(move, st, ci, moveIsCheck); // 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. @@ -1472,8 +1533,8 @@ namespace { && idle_thread_exists(threadID) && !AbortSearch && !thread_should_stop(threadID) - && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, approximateEval, depth, &moveCount, - &mp, dcCandidates, threadID, false)) + && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, approximateEval, + depth, &moveCount, &mp, threadID, false)) break; } @@ -1522,10 +1583,9 @@ namespace { EvalInfo ei; StateInfo st; - Bitboard dcCandidates; Move ttMove, move; Value staticValue, bestValue, value, futilityValue; - bool isCheck, enoughMaterial; + bool isCheck, enoughMaterial, moveIsCheck; const TTEntry* tte = NULL; int moveCount = 0; bool pvNode = (beta - alpha != 1); @@ -1595,7 +1655,6 @@ namespace { // queen promotions and checks (only if depth == 0) will be generated. MovePicker mp = MovePicker(pos, ttMove, depth, H); CheckInfo ci(pos); - dcCandidates = ci.dcCandidates; enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame; // Loop through the moves until no moves remain or a beta cutoff @@ -1608,12 +1667,15 @@ namespace { moveCount++; ss[ply].currentMove = move; + moveIsCheck = pos.move_is_check(move, ci); + // Futility pruning if ( enoughMaterial && !isCheck && !pvNode + && !moveIsCheck + && move != ttMove && !move_is_promotion(move) - && !pos.move_is_check(move, ci) && !pos.move_is_passed_pawn_push(move)) { futilityValue = staticValue @@ -1639,7 +1701,7 @@ namespace { continue; // Make and search the move - pos.do_move(move, st, dcCandidates); + pos.do_move(move, st, ci, moveIsCheck); value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID); pos.undo_move(move); @@ -1766,7 +1828,7 @@ namespace { // Make and search the move. StateInfo st; - pos.do_move(move, st, sp->dcCandidates); + pos.do_move(move, st, ci, moveIsCheck); // 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. @@ -1872,7 +1934,7 @@ namespace { // Make and search the move. StateInfo st; - pos.do_move(move, st, sp->dcCandidates); + pos.do_move(move, st, ci, moveIsCheck); // 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. @@ -2816,7 +2878,7 @@ namespace { bool split(const Position& p, SearchStack* sstck, int ply, Value* alpha, Value* beta, Value* bestValue, const Value futilityValue, const Value approximateEval, Depth depth, int* moves, - MovePicker* mp, Bitboard dcCandidates, int master, bool pvNode) { + MovePicker* mp, int master, bool pvNode) { assert(p.is_ok()); assert(sstck != NULL); @@ -2853,7 +2915,6 @@ namespace { splitPoint->alpha = pvNode? *alpha : (*beta - 1); splitPoint->beta = *beta; splitPoint->pvNode = pvNode; - splitPoint->dcCandidates = dcCandidates; splitPoint->bestValue = *bestValue; splitPoint->futilityValue = futilityValue; splitPoint->approximateEval = approximateEval;