From 2e96c513ad6113abb6bc4fdd4962cc1f6eed3d4a Mon Sep 17 00:00:00 2001 From: VoyagerOne Date: Sat, 5 Oct 2019 10:42:36 -0400 Subject: [PATCH] Introduce separate counter-move tables for captures Enhance counter-move history table by adding a capture/no-capture dimension, depending wether the previous move was a quiet move or a capture. This doubles the size of the table but provides more accurate move ordering. STC: LLR: 2.95 (-2.94,2.94) [0.50,4.50] Total: 79702 W: 17720 L: 17164 D: 44818 http://tests.stockfishchess.org/tests/view/5d97945e0ebc590c21aa724b LTC: LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 29147 W: 4907 L: 4651 D: 19589 http://tests.stockfishchess.org/tests/view/5d97ccb90ebc590c21aa7bc0 Closes https://github.com/official-stockfish/Stockfish/pull/2344 Bench: 4131643 --- src/movepick.cpp | 12 ++++++------ src/movepick.h | 2 +- src/search.cpp | 22 +++++++++++++--------- src/thread.cpp | 10 ++++++---- src/thread.h | 2 +- 5 files changed, 27 insertions(+), 21 deletions(-) diff --git a/src/movepick.cpp b/src/movepick.cpp index fab8cea8..e39f2afa 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -111,11 +111,11 @@ void MovePicker::score() { + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))]; else if (Type == QUIETS) - m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - + (*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)] / 2; + m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] + + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)] + + 2 * (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)] + + 2 * (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)] + + (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]; else // Type == EVASIONS { @@ -206,7 +206,7 @@ top: endMoves = generate(pos, cur); score(); - partial_insertion_sort(cur, endMoves, -4000 * depth); + partial_insertion_sort(cur, endMoves, -3000 * depth); } ++stage; diff --git a/src/movepick.h b/src/movepick.h index e916514d..105c95d7 100644 --- a/src/movepick.h +++ b/src/movepick.h @@ -80,7 +80,7 @@ struct Stats : public std::array, Size> {}; /// In stats table, D=0 means that the template parameter is not used enum StatsParams { NOT_USED = 0 }; - +enum StatsType { NoCaptures, Captures }; /// ButterflyHistory records how often quiet moves have been successful or /// unsuccessful during the current search, and is used for reduction and move diff --git a/src/search.cpp b/src/search.cpp index c05e72e0..156f6d1c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -334,7 +334,8 @@ void Thread::search() { std::memset(ss-7, 0, 10 * sizeof(Stack)); for (int i = 7; i > 0; i--) - (ss-i)->continuationHistory = &this->continuationHistory[NO_PIECE][0]; // Use as sentinel + (ss-i)->continuationHistory = &this->continuationHistory[0][NO_PIECE][0]; // Use as a sentinel + ss->pv = pv; bestValue = delta = alpha = -VALUE_INFINITE; @@ -595,12 +596,13 @@ namespace { Value bestValue, value, ttValue, eval, maxValue; bool ttHit, ttPv, inCheck, givesCheck, improving, doLMR; bool captureOrPromotion, doFullDepthSearch, moveCountPruning, ttCapture; - Piece movedPiece; + Piece movedPiece, priorCapture; int moveCount, captureCount, quietCount, singularLMR; // Step 1. Initialize node Thread* thisThread = pos.this_thread(); inCheck = pos.checkers(); + priorCapture = pos.captured_piece(); Color us = pos.side_to_move(); moveCount = captureCount = quietCount = singularLMR = ss->moveCount = 0; bestValue = -VALUE_INFINITE; @@ -680,7 +682,7 @@ namespace { update_quiet_stats(pos, ss, ttMove, nullptr, 0, stat_bonus(depth)); // Extra penalty for early quiet moves of the previous ply - if ((ss-1)->moveCount <= 2 && !pos.captured_piece()) + if ((ss-1)->moveCount <= 2 && !priorCapture) update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + 1)); } // Penalty for a quiet ttMove that fails low @@ -814,7 +816,7 @@ namespace { Depth R = (835 + 70 * depth) / 256 + std::min(int(eval - beta) / 185, 3); ss->currentMove = MOVE_NULL; - ss->continuationHistory = &thisThread->continuationHistory[NO_PIECE][0]; + ss->continuationHistory = &thisThread->continuationHistory[0][NO_PIECE][0]; pos.do_null_move(st); @@ -865,7 +867,7 @@ namespace { probCutCount++; ss->currentMove = move; - ss->continuationHistory = &thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)]; + ss->continuationHistory = &thisThread->continuationHistory[!!priorCapture][pos.moved_piece(move)][to_sq(move)]; assert(depth >= 5); @@ -1066,7 +1068,7 @@ moves_loop: // When in check, search starts from here // Update the current move (this must be done after singular extension search) ss->currentMove = move; - ss->continuationHistory = &thisThread->continuationHistory[movedPiece][to_sq(move)]; + ss->continuationHistory = &thisThread->continuationHistory[!!priorCapture][movedPiece][to_sq(move)]; // Step 15. Make the move pos.do_move(move, st, givesCheck); @@ -1279,13 +1281,13 @@ moves_loop: // When in check, search starts from here // Extra penalty for a quiet TT or main killer move in previous ply when it gets refuted if ( ((ss-1)->moveCount == 1 || ((ss-1)->currentMove == (ss-1)->killers[0])) - && !pos.captured_piece()) + && !priorCapture) update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + 1)); } // Bonus for prior countermove that caused the fail low else if ( (depth >= 3 || PvNode) - && !pos.captured_piece()) + && !priorCapture) update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth)); if (PvNode) @@ -1321,6 +1323,7 @@ moves_loop: // When in check, search starts from here Move ttMove, move, bestMove; Depth ttDepth; Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha; + Piece priorCapture; bool ttHit, pvHit, inCheck, givesCheck, evasionPrunable; int moveCount; @@ -1335,6 +1338,7 @@ moves_loop: // When in check, search starts from here (ss+1)->ply = ss->ply + 1; bestMove = MOVE_NONE; inCheck = pos.checkers(); + priorCapture = pos.captured_piece(); moveCount = 0; // Check for an immediate draw or maximum ply reached @@ -1472,7 +1476,7 @@ moves_loop: // When in check, search starts from here } ss->currentMove = move; - ss->continuationHistory = &thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)]; + ss->continuationHistory = &thisThread->continuationHistory[!!priorCapture][pos.moved_piece(move)][to_sq(move)]; // Make and search the move pos.do_move(move, st, givesCheck); diff --git a/src/thread.cpp b/src/thread.cpp index 19687aad..3c9473c2 100644 --- a/src/thread.cpp +++ b/src/thread.cpp @@ -70,11 +70,13 @@ void Thread::clear() { mainHistory.fill(0); captureHistory.fill(0); - for (auto& to : continuationHistory) - for (auto& h : to) - h->fill(0); + for (StatsType c : { NoCaptures, Captures }) + for (auto& to : continuationHistory[c]) + for (auto& h : to) + h->fill(0); - continuationHistory[NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1); + for (StatsType c : { NoCaptures, Captures }) + continuationHistory[c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1); } /// Thread::start_searching() wakes up the thread that will start the search diff --git a/src/thread.h b/src/thread.h index 79c6e43f..0a77d5b8 100644 --- a/src/thread.h +++ b/src/thread.h @@ -71,7 +71,7 @@ public: CounterMoveHistory counterMoves; ButterflyHistory mainHistory; CapturePieceToHistory captureHistory; - ContinuationHistory continuationHistory; + ContinuationHistory continuationHistory[2]; Score contempt; }; -- 2.39.2