X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=e2cf76b81b7d97fc312de720bf8a41c88c068e6e;hp=ccea71ca0842eaaa073cde03f9987ed934e4eaca;hb=79232be02a03a5e2225b30f843e9597fd85951dc;hpb=4840643fedbfc33d118cdc13c8435b062e3da99b diff --git a/src/search.cpp b/src/search.cpp index ccea71ca..e2cf76b8 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -87,6 +87,7 @@ namespace { void id_loop(Position& pos); Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); + void update_pv(Move* pv, Move move, Move* childPv); void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt); string uci_pv(const Position& pos, Depth depth, Value alpha, Value beta); @@ -394,8 +395,7 @@ namespace { assert(PvNode || (alpha == beta - 1)); assert(depth > DEPTH_ZERO); - PVEntry pv; - Move quietsSearched[64]; + Move pv[MAX_PLY+1], quietsSearched[64]; StateInfo st; const TTEntry *tte; SplitPoint* splitPoint; @@ -466,11 +466,8 @@ namespace { ss->ttMove = ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE; ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; - // At PV nodes we check for exact scores, whilst at non-PV nodes we check for - // a fail high/low. The biggest advantage to probing at PV nodes is to have a - // smooth experience in analysis mode. We don't probe at Root nodes otherwise - // we should also update RootMoveList to avoid bogus output. - if ( !PvNode + // At non-PV nodes we check for a fail high/low. We don't probe at PV nodes + if ( !PvNode && tte && tte->depth() >= depth && ttValue != VALUE_NONE // Only in case of TT access race @@ -865,14 +862,17 @@ moves_loop: // When in check and at SpNode search starts from here // For PV nodes only, do a full PV search on the first move or after a fail // high (in the latter case search only if value < beta), otherwise let the // parent node fail low with value <= alpha and to try another move. - if (PvNode && (moveCount == 1 || (value > alpha && (RootNode || value < beta)))) { - pv.pv[0] = MOVE_NONE; - (ss+1)->pv = &pv; + if (PvNode && (moveCount == 1 || (value > alpha && (RootNode || value < beta)))) + { + (ss+1)->pv = pv; + (ss+1)->pv[0] = MOVE_NONE; + value = newDepth < ONE_PLY ? givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : - search(pos, ss+1, -beta, -alpha, newDepth, false); } + // Step 17. Undo move pos.undo_move(move); @@ -901,8 +901,11 @@ moves_loop: // When in check and at SpNode search starts from here { rm.score = value; rm.pv.resize(1); - for (int i = 0; (ss+1)->pv && i < MAX_PLY && (ss+1)->pv->pv[i] != MOVE_NONE; ++i) - rm.pv.push_back((ss+1)->pv->pv[i]); + + assert((ss+1)->pv); + + for (Move* m = (ss+1)->pv; *m != MOVE_NONE; ++m) + rm.pv.push_back(*m); // We record how often the best move has been changed in each // iteration. This information is used for time management: When @@ -925,11 +928,8 @@ moves_loop: // When in check and at SpNode search starts from here { bestMove = SpNode ? splitPoint->bestMove = move : move; - if (NT == PV) { - ss->pv->update(move, (ss+1)->pv); - if (SpNode) - splitPoint->ss->pv->update(move, (ss+1)->pv); - } + if (PvNode && !RootNode) // Update pv even in fail-high case + update_pv(SpNode ? splitPoint->ss->pv : ss->pv, move, (ss+1)->pv); if (PvNode && value < beta) // Update alpha! Always alpha < beta alpha = SpNode ? splitPoint->alpha = value : value; @@ -1015,7 +1015,7 @@ moves_loop: // When in check and at SpNode search starts from here assert(PvNode || (alpha == beta - 1)); assert(depth <= DEPTH_ZERO); - PVEntry pv; + Move pv[MAX_PLY+1]; StateInfo st; const TTEntry* tte; Key posKey; @@ -1024,12 +1024,11 @@ moves_loop: // When in check and at SpNode search starts from here bool givesCheck, evasionPrunable; Depth ttDepth; - if (PvNode) { - // To flag BOUND_EXACT a node with eval above alpha and no available moves - oldAlpha = alpha; - - (ss+1)->pv = &pv; - ss->pv->pv[0] = MOVE_NONE; + if (PvNode) + { + oldAlpha = alpha; // To flag BOUND_EXACT when eval above alpha and no available moves + (ss+1)->pv = pv; + ss->pv[0] = MOVE_NONE; } ss->currentMove = bestMove = MOVE_NONE; @@ -1053,7 +1052,7 @@ moves_loop: // When in check and at SpNode search starts from here ttMove = tte ? tte->move() : MOVE_NONE; ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_NONE; - if ( !PvNode + if ( !PvNode && tte && tte->depth() >= ttDepth && ttValue != VALUE_NONE // Only in case of TT access race @@ -1180,8 +1179,8 @@ moves_loop: // When in check and at SpNode search starts from here if (value > alpha) { - if (PvNode) - ss->pv->update(move, &pv); + if (PvNode) // Update pv even in fail-high case + update_pv(ss->pv, move, (ss+1)->pv); if (PvNode && value < beta) // Update alpha here! Always alpha < beta { @@ -1239,6 +1238,15 @@ moves_loop: // When in check and at SpNode search starts from here } + // update_pv() adds current move and appends child pv[] + + void update_pv(Move* pv, Move move, Move* childPv) { + + for (*pv++ = move; childPv && *childPv != MOVE_NONE; ) + *pv++ = *childPv++; + *pv = MOVE_NONE; + } + // update_stats() updates killers, history, countermoves and followupmoves stats after a fail-high // of a quiet move. @@ -1252,7 +1260,7 @@ moves_loop: // When in check and at SpNode search starts from here // Increase history value of the cut-off move and decrease all the other // played quiet moves. - Value bonus = Value(4 * int(depth) * int(depth)); + Value bonus = Value(int(depth) * int(depth)); History.update(pos.moved_piece(move), to_sq(move), bonus); for (int i = 0; i < quietsCnt; ++i) { @@ -1371,15 +1379,17 @@ void RootMove::insert_pv_in_tt(Position& pos) { StateInfo state[MAX_PLY], *st = state; const TTEntry* tte; - int idx = 0; + size_t idx = 0; - for (; idx < int(pv.size()); ++idx) { + for ( ; idx < pv.size(); ++idx) + { tte = TT.probe(pos.key()); if (!tte || tte->move() != pv[idx]) // Don't overwrite correct entries TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[idx], VALUE_NONE); assert(MoveList(pos).contains(pv[idx])); + pos.do_move(pv[idx], *st++); }