Small cleanups 13

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 743449fa39c5b7e13cd81dc68cd44f90d53fdf41..78a1f7b6eb9e038a5c24f415dd127a2ddb67c13b 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -164,6 +164,8 @@ namespace {
   uint64_t perft(Position& pos, Depth depth) {
 
     StateInfo st;
+    ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
     uint64_t cnt, nodes = 0;
     const bool leaf = (depth == 2);
 
@@ -519,10 +521,14 @@ void Thread::search() {
           }
           double bestMoveInstability = 1 + 2 * totBestMoveChanges / Threads.size();
 
-          double totalTime = rootMoves.size() == 1 ? 0 :
-                             Time.optimum() * fallingEval * reduction * bestMoveInstability;
+          double totalTime = Time.optimum() * fallingEval * reduction * bestMoveInstability;
+
+          // Cap used time in case of a single legal move for a better viewer experience in tournaments
+          // yielding correct scores and sufficiently fast moves.
+          if (rootMoves.size() == 1)
+              totalTime = std::min(500.0, totalTime);
 
-          // Stop the search if we have exceeded the totalTime, at least 1ms search
+          // Stop the search if we have exceeded the totalTime
           if (Time.elapsed() > totalTime)
           {
               // If we are allowed to ponder do not stop the search now but
@@ -590,6 +596,8 @@ namespace {
 
     Move pv[MAX_PLY+1], capturesSearched[32], quietsSearched[64];
     StateInfo st;
+    ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
     TTEntry* tte;
     Key posKey;
     Move ttMove, move, excludedMove, bestMove;
@@ -1050,7 +1058,7 @@ moves_loop: // When in check, search starts from here
                   && captureHistory[movedPiece][to_sq(move)][type_of(pos.piece_on(to_sq(move)))] < 0)
                   continue;
 
-              // See based pruning
+              // SEE based pruning
               if (!pos.see_ge(move, Value(-221) * depth)) // (~25 Elo)
                   continue;
           }
@@ -1153,7 +1161,7 @@ moves_loop: // When in check, search starts from here
           if (thisThread->ttHitAverage > 509 * TtHitAverageResolution * TtHitAverageWindow / 1024)
               r--;
 
-          // Reduction if other threads are searching this position
+          // Increase reduction if other threads are searching this position
           if (th.marked())
               r++;
 
@@ -1161,6 +1169,10 @@ moves_loop: // When in check, search starts from here
           if (ss->ttPv)
               r -= 2;
 
+          // Increase reduction at root and non-PV nodes when the best move does not change frequently
+          if ((rootNode || !PvNode) && depth > 10 && thisThread->bestMoveChanges <= 2)
+              r++;
+
           if (moveCountPruning && !formerPv)
               r++;
 
@@ -1403,6 +1415,8 @@ moves_loop: // When in check, search starts from here
 
     Move pv[MAX_PLY+1];
     StateInfo st;
+    ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
     TTEntry* tte;
     Key posKey;
     Move ttMove, move, bestMove;
@@ -1515,7 +1529,7 @@ moves_loop: // When in check, search starts from here
       moveCount++;
 
       // Futility pruning
-      if (   !ss->inCheck
+      if (    bestValue > VALUE_TB_LOSS_IN_MAX_PLY
           && !givesCheck
           &&  futilityBase > -VALUE_KNOWN_WIN
           && !pos.advanced_pawn_push(move))
@@ -1542,7 +1556,7 @@ moves_loop: // When in check, search starts from here
       }
 
       // Do not search moves with negative SEE values
-      if (   !ss->inCheck
+      if (    bestValue > VALUE_TB_LOSS_IN_MAX_PLY
           && !(givesCheck && pos.is_discovery_check_on_king(~pos.side_to_move(), move))
           && !pos.see_ge(move))
           continue;
@@ -1898,6 +1912,8 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) {
 bool RootMove::extract_ponder_from_tt(Position& pos) {
 
     StateInfo st;
+    ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize);
+
     bool ttHit;
 
     assert(pv.size() == 1);