X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=ed1cdc7faa0187184d3a1ac14df6a2b7ab269d2e;hp=a4ea9aa4b36e455057c66aa6934b99896fe62dca;hb=ee9f650242899373136a76d9549db7f2858c1b06;hpb=93bc05cf693064b80bf70cb97c6d110ab8f0a015 diff --git a/src/search.cpp b/src/search.cpp index a4ea9aa4..ed1cdc7f 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -238,20 +238,20 @@ namespace { Depth depth, int ply, int threadID); void sp_search(SplitPoint *sp, int threadID); void sp_search_pv(SplitPoint *sp, int threadID); - void init_search_stack(SearchStack ss); + void init_search_stack(SearchStack& ss); void init_search_stack(SearchStack ss[]); void init_node(const Position &pos, SearchStack ss[], int ply, int threadID); void update_pv(SearchStack ss[], int ply); void sp_update_pv(SearchStack *pss, SearchStack ss[], int ply); bool connected_moves(const Position &pos, Move m1, Move m2); - Depth extension(const Position &pos, Move m, bool pvNode, bool check, - bool singleReply, bool mateThreat); + bool move_is_killer(Move m, const SearchStack& ss); + Depth extension(const Position &pos, Move m, bool pvNode, bool check, bool singleReply, bool mateThreat, bool* extendable); bool ok_to_do_nullmove(const Position &pos); bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d); bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply); bool ok_to_history(const Position &pos, Move m); - void update_history(const Position& pos, Move m, Depth depth, - Move movesSearched[], int moveCount); + void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount); + void update_killers(Move m, SearchStack& ss); bool fail_high_ply_1(); int current_search_time(); @@ -430,8 +430,8 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, TimeAdvantage = myTime - oppTime; if (!movesToGo) // Sudden death time control - { - if (increment) + { + if (myIncrement) { MaxSearchTime = myTime / 30 + myIncrement; AbsoluteMaxSearchTime = Max(myTime / 4, myIncrement - 100); @@ -778,7 +778,8 @@ namespace { << " currmovenumber " << i + 1 << std::endl; // Decide search depth for this move - ext = extension(pos, move, true, pos.move_is_check(move), false, false); + bool dummy; + ext = extension(pos, move, true, pos.move_is_check(move), false, false, &dummy); newDepth = (Iteration - 2) * OnePly + ext + InitialDepth; // Make the move, and search it @@ -795,7 +796,7 @@ namespace { if (Problem && StopOnPonderhit) StopOnPonderhit = false; - } + } else { value = -search(pos, ss, -alpha, newDepth, 1, true, 0); @@ -978,7 +979,8 @@ namespace { ss[ply].currentMoveCaptureValue = Value(0); // Decide the new search depth - Depth ext = extension(pos, move, true, moveIsCheck, singleReply, mateThreat); + bool extendable; + Depth ext = extension(pos, move, true, moveIsCheck, singleReply, mateThreat, &extendable); Depth newDepth = depth - OnePly + ext; // Make and search the move @@ -992,14 +994,13 @@ 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. if ( depth >= 2*OnePly - && ext == Depth(0) + && !extendable && moveCount >= LMRPVMoves && !moveIsCapture && !move_promotion(move) && !moveIsPassedPawnPush && !move_is_castle(move) - && move != ss[ply].killers[0] - && move != ss[ply].killers[1]) + && !move_is_killer(move, ss[ply])) { ss[ply].reduction = OnePly; value = -search(pos, ss, -alpha, newDepth-OnePly, ply+1, true, threadID); @@ -1081,11 +1082,7 @@ namespace { if (ok_to_history(pos, m)) // Only non capture moves are considered { update_history(pos, m, depth, movesSearched, moveCount); - if (m != ss[ply].killers[0]) - { - ss[ply].killers[1] = ss[ply].killers[0]; - ss[ply].killers[0] = m; - } + update_killers(m, ss[ply]); } TT.store(pos, value_to_tt(bestValue, ply), depth, m, VALUE_TYPE_LOWER); } @@ -1230,12 +1227,13 @@ namespace { movesSearched[moveCount++] = ss[ply].currentMove = move; // Decide the new search depth - Depth ext = extension(pos, move, false, moveIsCheck, singleReply, mateThreat); + bool extendable; + Depth ext = extension(pos, move, false, moveIsCheck, singleReply, mateThreat, &extendable); Depth newDepth = depth - OnePly + ext; // Futility pruning if ( useFutilityPruning - && ext == Depth(0) + && !extendable && !moveIsCapture && !moveIsPassedPawnPush && !move_promotion(move)) @@ -1266,14 +1264,13 @@ 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. if ( depth >= 2*OnePly - && ext == Depth(0) + && !extendable && moveCount >= LMRNonPVMoves && !moveIsCapture && !move_promotion(move) && !moveIsPassedPawnPush && !move_is_castle(move) - && move != ss[ply].killers[0] - && move != ss[ply].killers[1]) + && !move_is_killer(move, ss[ply])) { ss[ply].reduction = OnePly; value = -search(pos, ss, -(beta-1), newDepth-OnePly, ply+1, true, threadID); @@ -1332,11 +1329,7 @@ namespace { if (ok_to_history(pos, m)) // Only non capture moves are considered { update_history(pos, m, depth, movesSearched, moveCount); - if (m != ss[ply].killers[0]) - { - ss[ply].killers[1] = ss[ply].killers[0]; - ss[ply].killers[0] = m; - } + update_killers(m, ss[ply]); } TT.store(pos, value_to_tt(bestValue, ply), depth, m, VALUE_TYPE_LOWER); } @@ -1440,7 +1433,6 @@ namespace { // Don't search captures and checks with negative SEE values if ( !isCheck && !move_promotion(move) - && !pvNode && (pos.midgame_value_of_piece_on(move_from(move)) > pos.midgame_value_of_piece_on(move_to(move))) && pos.see(move) < 0) @@ -1481,12 +1473,7 @@ namespace { if (alpha >= beta && ok_to_history(pos, m)) // Only non capture moves are considered { // Wrong to update history when depth is <= 0 - - if (m != ss[ply].killers[0]) - { - ss[ply].killers[1] = ss[ply].killers[0]; - ss[ply].killers[0] = m; - } + update_killers(m, ss[ply]); } return bestValue; } @@ -1531,12 +1518,13 @@ namespace { ss[sp->ply].currentMove = move; // Decide the new search depth. - Depth ext = extension(pos, move, false, moveIsCheck, false, false); + bool extendable; + Depth ext = extension(pos, move, false, moveIsCheck, false, false, &extendable); Depth newDepth = sp->depth - OnePly + ext; // Prune? if ( useFutilityPruning - && ext == Depth(0) + && !extendable && !moveIsCapture && !moveIsPassedPawnPush && !move_promotion(move) @@ -1550,14 +1538,13 @@ 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. - if ( ext == Depth(0) + if ( !extendable && moveCount >= LMRNonPVMoves && !moveIsCapture && !moveIsPassedPawnPush && !move_promotion(move) && !move_is_castle(move) - && move != ss[sp->ply].killers[0] - && move != ss[sp->ply].killers[1]) + && !move_is_killer(move, ss[sp->ply])) { ss[sp->ply].reduction = OnePly; value = -search(pos, ss, -(sp->beta-1), newDepth - OnePly, sp->ply+1, true, threadID); @@ -1649,7 +1636,8 @@ namespace { ss[sp->ply].currentMove = move; // Decide the new search depth. - Depth ext = extension(pos, move, true, moveIsCheck, false, false); + bool extendable; + Depth ext = extension(pos, move, true, moveIsCheck, false, false, &extendable); Depth newDepth = sp->depth - OnePly + ext; // Make and search the move. @@ -1658,14 +1646,13 @@ 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. - if ( ext == Depth(0) + if ( !extendable && moveCount >= LMRPVMoves && !moveIsCapture && !moveIsPassedPawnPush && !move_promotion(move) && !move_is_castle(move) - && move != ss[sp->ply].killers[0] - && move != ss[sp->ply].killers[1]) + && !move_is_killer(move, ss[sp->ply])) { ss[sp->ply].reduction = OnePly; value = -search(pos, ss, -sp->alpha, newDepth - OnePly, sp->ply+1, true, threadID); @@ -1896,7 +1883,7 @@ namespace { // init_search_stack() initializes a search stack at the beginning of a // new search from the root. - void init_search_stack(SearchStack ss) { + void init_search_stack(SearchStack& ss) { ss.pv[0] = MOVE_NONE; ss.pv[1] = MOVE_NONE; @@ -1904,7 +1891,7 @@ namespace { ss.threatMove = MOVE_NONE; ss.reduction = Depth(0); for (int j = 0; j < KILLER_MAX; j++) - ss.killers[j] = MOVE_NONE; + ss.killers[j] = MOVE_NONE; } void init_search_stack(SearchStack ss[]) { @@ -1941,13 +1928,13 @@ namespace { NodesSincePoll = 0; } } - ss[ply].pv[ply] = ss[ply].pv[ply+1] = ss[ply].currentMove = MOVE_NONE; ss[ply+2].mateKiller = MOVE_NONE; - ss[ply+2].killers[0] = ss[ply+2].killers[1] = MOVE_NONE; ss[ply].threatMove = MOVE_NONE; ss[ply].reduction = Depth(0); ss[ply].currentMoveCaptureValue = Value(0); + for (int j = 0; j < KILLER_MAX; j++) + ss[ply+2].killers[j] = MOVE_NONE; if(Threads[threadID].printCurrentLine) print_current_line(ss, ply, threadID); @@ -2050,14 +2037,29 @@ namespace { } + // move_is_killer() checks if the given move is among the + // killer moves of that ply. + + bool move_is_killer(Move m, const SearchStack& ss) { + + const Move* k = ss.killers; + for (int i = 0; i < KILLER_MAX; i++, k++) + if (*k == m) + return true; + + return false; + } + + // extension() decides whether a move should be searched with normal depth, // or with extended depth. Certain classes of moves (checking moves, in // particular) are searched with bigger depth than ordinary moves. Depth extension(const Position &pos, Move m, bool pvNode, - bool check, bool singleReply, bool mateThreat) { + bool check, bool singleReply, bool mateThreat, bool* extendable) { Depth result = Depth(0); + *extendable = check || singleReply || mateThreat; if (check) result += CheckExtension[pvNode]; @@ -2065,26 +2067,37 @@ namespace { if (singleReply) result += SingleReplyExtension[pvNode]; + if (mateThreat) + result += MateThreatExtension[pvNode]; + if (pos.move_is_pawn_push_to_7th(m)) + { result += PawnPushTo7thExtension[pvNode]; - + *extendable = true; + } if (pos.move_is_passed_pawn_push(m)) + { result += PassedPawnExtension[pvNode]; - - if (mateThreat) - result += MateThreatExtension[pvNode]; + *extendable = true; + } if ( pos.midgame_value_of_piece_on(move_to(m)) >= RookValueMidgame && ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) - pos.midgame_value_of_piece_on(move_to(m)) == Value(0)) && !move_promotion(m)) + { result += PawnEndgameExtension[pvNode]; - + *extendable = true; + } + if ( pvNode && pos.move_is_capture(m) && pos.type_of_piece_on(move_to(m)) != PAWN && pos.see(m) >= 0) + { result += OnePly/2; + *extendable = true; + } return Min(result, OnePly); } @@ -2197,6 +2210,21 @@ namespace { } } + + // update_killers() add a good move that produced a beta-cutoff + // among the killer moves of that ply. + + void update_killers(Move m, SearchStack& ss) { + + if (m == ss.killers[0]) + return; + + for (int i = KILLER_MAX - 1; i > 0; i--) + ss.killers[i] = ss.killers[i - 1]; + + ss.killers[0] = m; + } + // fail_high_ply_1() checks if some thread is currently resolving a fail // high at ply 1 at the node below the first root node. This information // is used for time managment.