From: pb00067 Date: Wed, 15 Dec 2021 07:49:44 +0000 (+0100) Subject: Remove lowPly history X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=dc5d9bdfee70f4267d9a49ad71e5ee478dd50ca5 Remove lowPly history Seems that after pull request #3731 (Capping stat bonus at 2000) this heuristic is no longer useful. STC: https://tests.stockfishchess.org/tests/view/61b8d0e2dffbe89a35815444 LLR: 2.94 (-2.94,2.94) <-2.25,0.25> Total: 30672 W: 7974 L: 7812 D: 14886 Ptnml(0-2): 106, 3436, 8072, 3634, 88 LTC: https://tests.stockfishchess.org/tests/view/61b8e90cdffbe89a35815a67 LLR: 2.94 (-2.94,2.94) <-2.25,0.25> Total: 42448 W: 10884 L: 10751 D: 20813 Ptnml(0-2): 23, 4394, 12267, 4507, 33 closes https://github.com/official-stockfish/Stockfish/pull/3853 bench: 4474950 --- diff --git a/src/movepick.cpp b/src/movepick.cpp index 20640fe2..6aa1954b 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -56,11 +56,14 @@ namespace { /// ordering is at the current node. /// MovePicker constructor for the main search -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, const LowPlyHistory* lp, - const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, const Move* killers, int pl) - : pos(p), mainHistory(mh), lowPlyHistory(lp), captureHistory(cph), continuationHistory(ch), - ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) { - +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, + const CapturePieceToHistory* cph, + const PieceToHistory** ch, + Move cm, + const Move* killers) + : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), + ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) +{ assert(d > 0); stage = (pos.checkers() ? EVASION_TT : MAIN_TT) + @@ -69,9 +72,11 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHist /// MovePicker constructor for quiescence search MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, - const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs) - : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) { - + const CapturePieceToHistory* cph, + const PieceToHistory** ch, + Square rs) + : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) +{ assert(d <= 0); stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) + @@ -83,8 +88,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHist /// MovePicker constructor for ProbCut: we generate captures with SEE greater /// than or equal to the given threshold. MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph) - : pos(p), captureHistory(cph), ttMove(ttm), threshold(th) { - + : pos(p), captureHistory(cph), ttMove(ttm), threshold(th) +{ assert(!pos.checkers()); stage = PROBCUT_TT + !(ttm && pos.capture(ttm) @@ -110,8 +115,7 @@ void MovePicker::score() { + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)] + (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)] + (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)] - + (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)] - + (ply < MAX_LPH ? 6 * (*lowPlyHistory)[ply][from_to(m)] : 0); + + (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]; else // Type == EVASIONS { diff --git a/src/movepick.h b/src/movepick.h index 7d78886f..426bac89 100644 --- a/src/movepick.h +++ b/src/movepick.h @@ -88,12 +88,6 @@ enum StatsType { NoCaptures, Captures }; /// the move's from and to squares, see www.chessprogramming.org/Butterfly_Boards typedef Stats ButterflyHistory; -/// At higher depths LowPlyHistory records successful quiet moves near the root -/// and quiet moves which are/were in the PV (ttPv). LowPlyHistory is populated during -/// iterative deepening and at each new search the data is shifted down by 2 plies -constexpr int MAX_LPH = 4; -typedef Stats LowPlyHistory; - /// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous /// move, see www.chessprogramming.org/Countermove_Heuristic typedef Stats CounterMoveHistory; @@ -123,18 +117,16 @@ class MovePicker { public: MovePicker(const MovePicker&) = delete; MovePicker& operator=(const MovePicker&) = delete; - MovePicker(const Position&, Move, Value, const CapturePieceToHistory*); MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const CapturePieceToHistory*, const PieceToHistory**, - Square); + Move, + const Move*); MovePicker(const Position&, Move, Depth, const ButterflyHistory*, - const LowPlyHistory*, const CapturePieceToHistory*, const PieceToHistory**, - Move, - const Move*, - int); + Square); + MovePicker(const Position&, Move, Value, const CapturePieceToHistory*); Move next_move(bool skipQuiets = false); private: @@ -145,7 +137,6 @@ private: const Position& pos; const ButterflyHistory* mainHistory; - const LowPlyHistory* lowPlyHistory; const CapturePieceToHistory* captureHistory; const PieceToHistory** continuationHistory; Move ttMove; @@ -154,7 +145,6 @@ private: Square recaptureSquare; Value threshold; Depth depth; - int ply; ExtMove moves[MAX_MOVES]; }; diff --git a/src/search.cpp b/src/search.cpp index 01d97646..2abfbaf2 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -141,7 +141,7 @@ namespace { Value value_from_tt(Value v, int ply, int r50c); void update_pv(Move* pv, Move move, Move* childPv); void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus); - void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus, int depth); + void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus); void update_all_stats(const Position& pos, Stack* ss, Move bestMove, Value bestValue, Value beta, Square prevSq, Move* quietsSearched, int quietCount, Move* capturesSearched, int captureCount, Depth depth); @@ -317,9 +317,6 @@ void Thread::search() { mainThread->iterValue[i] = mainThread->bestPreviousScore; } - std::copy(&lowPlyHistory[2][0], &lowPlyHistory.back().back() + 1, &lowPlyHistory[0][0]); - std::fill(&lowPlyHistory[MAX_LPH - 2][0], &lowPlyHistory.back().back() + 1, 0); - size_t multiPV = size_t(Options["MultiPV"]); Skill skill(Options["Skill Level"], Options["UCI_LimitStrength"] ? int(Options["UCI_Elo"]) : 0); @@ -666,14 +663,6 @@ namespace { if (!excludedMove) ss->ttPv = PvNode || (ss->ttHit && tte->is_pv()); - // Update low ply history for previous move if we are near root and position is or has been in PV - if ( ss->ttPv - && depth > 12 - && ss->ply - 1 < MAX_LPH - && !priorCapture - && is_ok((ss-1)->currentMove)) - thisThread->lowPlyHistory[ss->ply - 1][from_to((ss-1)->currentMove)] << stat_bonus(depth - 5); - // At non-PV nodes we check for an early TT cutoff if ( !PvNode && ss->ttHit @@ -689,7 +678,7 @@ namespace { { // Bonus for a quiet ttMove that fails high if (!ttCapture) - update_quiet_stats(pos, ss, ttMove, stat_bonus(depth), depth); + update_quiet_stats(pos, ss, ttMove, stat_bonus(depth)); // Extra penalty for early quiet moves of the previous ply if ((ss-1)->moveCount <= 2 && !priorCapture) @@ -973,12 +962,10 @@ moves_loop: // When in check, search starts here Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq]; MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, - &thisThread->lowPlyHistory, &captureHistory, contHist, countermove, - ss->killers, - ss->ply); + ss->killers); value = bestValue; moveCountPruning = false; @@ -1708,7 +1695,7 @@ moves_loop: // When in check, search starts here if (!pos.capture_or_promotion(bestMove)) { // Increase stats for the best move in case it was a quiet move - update_quiet_stats(pos, ss, bestMove, bonus2, depth); + update_quiet_stats(pos, ss, bestMove, bonus2); // Decrease stats for all non-best quiet moves for (int i = 0; i < quietCount; ++i) @@ -1755,7 +1742,7 @@ moves_loop: // When in check, search starts here // update_quiet_stats() updates move sorting heuristics - void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus, int depth) { + void update_quiet_stats(const Position& pos, Stack* ss, Move move, int bonus) { // Update killers if (ss->killers[0] != move) @@ -1775,10 +1762,6 @@ moves_loop: // When in check, search starts here Square prevSq = to_sq((ss-1)->currentMove); thisThread->counterMoves[pos.piece_on(prevSq)][prevSq] = move; } - - // Update low ply history - if (depth > 11 && ss->ply < MAX_LPH) - thisThread->lowPlyHistory[ss->ply][from_to(move)] << stat_bonus(depth - 7); } // When playing with strength handicap, choose best move among a set of RootMoves diff --git a/src/thread.cpp b/src/thread.cpp index ed3accc5..099efbad 100644 --- a/src/thread.cpp +++ b/src/thread.cpp @@ -59,7 +59,6 @@ void Thread::clear() { counterMoves.fill(MOVE_NONE); mainHistory.fill(0); - lowPlyHistory.fill(0); captureHistory.fill(0); for (bool inCheck : { false, true }) diff --git a/src/thread.h b/src/thread.h index 37c6452b..6bc1be65 100644 --- a/src/thread.h +++ b/src/thread.h @@ -77,7 +77,6 @@ public: Value rootDelta; CounterMoveHistory counterMoves; ButterflyHistory mainHistory; - LowPlyHistory lowPlyHistory; CapturePieceToHistory captureHistory; ContinuationHistory continuationHistory[2][2]; Score trend;