Cleanup and optimize SSE/AVX code

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 201cd974d58dde631976c9da140c7e8bedddf1b7..3d2bb4222953bfe78c29f495f20481b219db312f 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1072,7 +1072,7 @@ moves_loop: // When in check, search starts from here
       // then that move is singular and should be extended. To verify this we do
       // a reduced search on all the other moves but the ttMove and if the
       // result is lower than ttValue minus a margin, then we will extend the ttMove.
-      if (    depth >= 6
+      if (    depth >= 7
           &&  move == ttMove
           && !rootNode
           && !excludedMove // Avoid recursive singular search
@@ -1131,7 +1131,8 @@ moves_loop: // When in check, search starts from here
           extension = 1;
 
       // Castling extension
-      if (type_of(move) == CASTLING)
+      if (   type_of(move) == CASTLING
+          && popcount(pos.pieces(us) & ~pos.pieces(PAWN) & (to_sq(move) & KingSide ? KingSide : QueenSide)) <= 3)
           extension = 1;
 
       // Late irreversible move extension
@@ -1159,7 +1160,7 @@ moves_loop: // When in check, search starts from here
       // Step 16. Reduced depth search (LMR, ~200 Elo). If the move fails high it will be
       // re-searched at full depth.
       if (    depth >= 3
-          &&  moveCount > 1 + 2 * rootNode
+          &&  moveCount > 1 + 2 * rootNode + 2 * (PvNode && abs(bestValue) < 2)
           && (!rootNode || thisThread->best_move_count(move) == 0)
           && (  !captureOrPromotion
               || moveCountPruning