From: Marco Costalba Date: Sat, 28 May 2011 11:13:42 +0000 (+0100) Subject: Unify search() template parameters X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=013dc43d5d297ee78526f8d03651915673cf2d49 Unify search() template parameters No functional change. Signed-off-by: Marco Costalba --- diff --git a/src/search.cpp b/src/search.cpp index dc6ad98b..cea95b47 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -47,7 +47,7 @@ namespace { const bool FakeSplit = false; // Different node types, used as template parameter - enum NodeType { NonPV, PV }; + enum NodeType { Root, PV, NonPV, SplitPointPV, SplitPointNonPV }; // RootMove struct is used for moves at the root of the tree. For each root // move, we store two scores, a node count, and a PV (really a refutation @@ -189,9 +189,9 @@ namespace { // Reduction lookup tables (initialized at startup) and their access function int8_t Reductions[2][64][64]; // [pv][depth][moveNumber] - template inline Depth reduction(Depth d, int mn) { + template inline Depth reduction(Depth d, int mn) { - return (Depth) Reductions[PV][Min(d / ONE_PLY, 63)][Min(mn, 63)]; + return (Depth) Reductions[PvNode][Min(d / ONE_PLY, 63)][Min(mn, 63)]; } // Easy move margin. An easy move candidate must be at least this much @@ -233,20 +233,13 @@ namespace { Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove); - template + template Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth); - template + template Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth); - template - inline Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) { - - return depth < ONE_PLY ? qsearch(pos, ss, alpha, beta, DEPTH_ZERO) - : search(pos, ss, alpha, beta, depth); - } - - template + template Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool* dangerous); bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bValue); @@ -304,8 +297,8 @@ void init_search() { { double pvRed = log(double(hd)) * log(double(mc)) / 3.0; double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25; - Reductions[PV][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0); - Reductions[NonPV][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0); + Reductions[1][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0); + Reductions[0][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0); } // Init futility margins array @@ -541,7 +534,7 @@ namespace { // research with bigger window until not failing high/low anymore. do { // Search starting from ss+1 to allow calling update_gains() - value = search(pos, ss+1, alpha, beta, depth * ONE_PLY); + value = search(pos, ss+1, alpha, beta, depth * ONE_PLY); // Write PV back to transposition table in case the relevant entries // have been overwritten during the search. @@ -663,9 +656,13 @@ namespace { // all this work again. We also don't need to store anything to the hash table // here: This is taken care of after we return from the split point. - template + template Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) { + const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV); + const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV); + const bool RootNode = (NT == Root); + assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE); assert(beta > alpha && beta <= VALUE_INFINITE); assert(PvNode || alpha == beta - 1); @@ -703,7 +700,7 @@ namespace { threatMove = sp->threatMove; goto split_point_start; } - else if (Root) + else if (RootNode) bestValue = alpha; // Step 1. Initialize node and poll. Polling can abort search @@ -721,7 +718,7 @@ namespace { if (( StopRequest || Threads[threadID].cutoff_occurred() || pos.is_draw() - || ss->ply > PLY_MAX) && !Root) + || ss->ply > PLY_MAX) && !RootNode) return VALUE_DRAW; // Step 3. Mate distance pruning @@ -742,7 +739,7 @@ namespace { // At PV nodes we check for exact scores, while at non-PV nodes we check for // a fail high/low. Biggest advantage at probing at PV nodes is to have a // smooth experience in analysis mode. - if ( !Root + if ( !RootNode && tte && (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT : ok_to_use_TT(tte, depth, beta, ss->ply))) @@ -821,7 +818,8 @@ namespace { pos.do_null_move(st); (ss+1)->skipNullMove = true; - nullValue = -search(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY); + nullValue = depth-R*ONE_PLY < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) + : - search(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY); (ss+1)->skipNullMove = false; pos.undo_null_move(); @@ -868,7 +866,7 @@ namespace { Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2); ss->skipNullMove = true; - search(pos, ss, alpha, beta, d); + search(pos, ss, alpha, beta, d); ss->skipNullMove = false; tte = TT.probe(posKey); @@ -878,12 +876,12 @@ namespace { split_point_start: // At split points actual search starts from here // Initialize a MovePicker object for the current position - MovePickerExt mp(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); + MovePickerExt mp(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); CheckInfo ci(pos); Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); ss->bestMove = MOVE_NONE; futilityBase = ss->eval + ss->evalMargin; - singularExtensionNode = !Root + singularExtensionNode = !RootNode && !SpNode && depth >= SingularExtensionDepth[PvNode] && ttMove != MOVE_NONE @@ -919,7 +917,7 @@ split_point_start: // At split points actual search starts from here else moveCount++; - if (Root) + if (RootNode) { // This is used by time management FirstRootMove = (moveCount == 1); @@ -941,7 +939,7 @@ split_point_start: // At split points actual search starts from here } // At Root and at first iteration do a PV search on all the moves to score root moves - isPvMove = (PvNode && moveCount <= (Root ? depth <= ONE_PLY ? 1000 : MultiPV : 1)); + isPvMove = (PvNode && moveCount <= (RootNode ? depth <= ONE_PLY ? 1000 : MultiPV : 1)); givesCheck = pos.move_gives_check(move, ci); captureOrPromotion = pos.move_is_capture(move) || move_is_promotion(move); @@ -999,7 +997,7 @@ split_point_start: // At split points actual search starts from here // Value based pruning // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth, // but fixing this made program slightly weaker. - Depth predictedDepth = newDepth - reduction(depth, moveCount); + Depth predictedDepth = newDepth - reduction(depth, moveCount); futilityValueScaled = futilityBase + futility_margin(predictedDepth, moveCount) + H.gain(pos.piece_on(move_from(move)), move_to(move)); @@ -1049,10 +1047,11 @@ split_point_start: // At split points actual search starts from here if (isPvMove) { // Aspiration window is disabled in multi-pv case - if (Root && MultiPV > 1) + if (RootNode && MultiPV > 1) alpha = -VALUE_INFINITE; - value = -search(pos, ss+1, -beta, -alpha, newDepth); + value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) + : - search(pos, ss+1, -beta, -alpha, newDepth); } else { @@ -1072,8 +1071,8 @@ split_point_start: // At split points actual search starts from here if (ss->reduction) { Depth d = newDepth - ss->reduction; - value = -search(pos, ss+1, -(alpha+1), -alpha, d); - + value = d < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) + : - search(pos, ss+1, -(alpha+1), -alpha, d); doFullDepthSearch = (value > alpha); } ss->reduction = DEPTH_ZERO; // Restore original reduction @@ -1092,7 +1091,8 @@ split_point_start: // At split points actual search starts from here ss->reduction = 3 * ONE_PLY; Value rAlpha = alpha - 300; Depth d = newDepth - ss->reduction; - value = -search(pos, ss+1, -(rAlpha+1), -rAlpha, d); + value = d < ONE_PLY ? -qsearch(pos, ss+1, -(rAlpha+1), -rAlpha, DEPTH_ZERO) + : - search(pos, ss+1, -(rAlpha+1), -rAlpha, d); doFullDepthSearch = (value > rAlpha); ss->reduction = DEPTH_ZERO; // Restore original reduction } @@ -1101,13 +1101,15 @@ split_point_start: // At split points actual search starts from here if (doFullDepthSearch) { alpha = SpNode ? sp->alpha : alpha; - value = -search(pos, ss+1, -(alpha+1), -alpha, newDepth); + value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) + : - search(pos, ss+1, -(alpha+1), -alpha, newDepth); // Step extra. pv search (only in PV nodes) // Search only for possible new PV nodes, if instead value >= beta then // parent node fails low with value <= alpha and tries another move. - if (PvNode && value > alpha && (Root || value < beta)) - value = -search(pos, ss+1, -beta, -alpha, newDepth); + if (PvNode && value > alpha && (RootNode || value < beta)) + value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) + : - search(pos, ss+1, -beta, -alpha, newDepth); } } @@ -1131,7 +1133,7 @@ split_point_start: // At split points actual search starts from here if (SpNode) sp->bestValue = value; - if (!Root && value > alpha) + if (!RootNode && value > alpha) { if (PvNode && value < beta) // We want always alpha < beta { @@ -1153,7 +1155,7 @@ split_point_start: // At split points actual search starts from here } } - if (Root) + if (RootNode) { // Finished searching the move. If StopRequest is true, the search // was aborted because the user interrupted the search or because we @@ -1192,10 +1194,10 @@ split_point_start: // At split points actual search starts from here else mp.rm->pv_score = -VALUE_INFINITE; - } // Root + } // RootNode // Step 18. Check for split - if ( !Root + if ( !RootNode && !SpNode && depth >= Threads.min_split_depth() && bestValue < beta @@ -1255,9 +1257,12 @@ split_point_start: // At split points actual search starts from here // search function when the remaining depth is zero (or, to be more precise, // less than ONE_PLY). - template + template Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) { + const bool PvNode = (NT == PV); + + assert(NT == PV || NT == NonPV); assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE); assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE); assert(PvNode || alpha == beta - 1); @@ -1417,7 +1422,7 @@ split_point_start: // At split points actual search starts from here // Make and search the move pos.do_move(move, st, ci, givesCheck); - value = -qsearch(pos, ss+1, -beta, -alpha, depth-ONE_PLY); + value = -qsearch(pos, ss+1, -beta, -alpha, depth-ONE_PLY); pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1596,7 +1601,7 @@ split_point_start: // At split points actual search starts from here // any case are marked as 'dangerous'. Note that also if a move is not // extended, as example because the corresponding UCI option is set to zero, // the move is marked as 'dangerous' so, at least, we avoid to prune it. - template + template Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool* dangerous) { @@ -2178,9 +2183,9 @@ void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) { (ss+1)->sp = tsp; if (tsp->pvNode) - search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); + search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); else - search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); + search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); assert(threads[threadID].state == Thread::SEARCHING);