Remove unnecessay legality check

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 886ed52ca0bbf65f3fca476d4bffe12a650f44d2..e5d18f776f176b04d476852904ca774c401185ce 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1028,7 +1028,7 @@ moves_loop: // When in check, search starts from here
                   continue;
 
               // Futility pruning: parent node (~5 Elo)
-              if (   lmrDepth < 6
+              if (   lmrDepth < 8
                   && !ss->inCheck
                   && ss->staticEval + 284 + 188 * lmrDepth <= alpha
                   &&  (*contHist[0])[movedPiece][to_sq(move)]
@@ -1079,8 +1079,7 @@ moves_loop: // When in check, search starts from here
        /* &&  ttValue != VALUE_NONE Already implicit in the next condition */
           &&  abs(ttValue) < VALUE_KNOWN_WIN
           && (tte->bound() & BOUND_LOWER)
-          &&  tte->depth() >= depth - 3
-          &&  pos.legal(move))
+          &&  tte->depth() >= depth - 3)
       {
           Value singularBeta = ttValue - ((formerPv + 4) * depth) / 2;
           Depth singularDepth = (depth - 1 + 3 * formerPv) / 2;
@@ -1135,6 +1134,12 @@ moves_loop: // When in check, search starts from here
       if (type_of(move) == CASTLING)
           extension = 1;
 
+      // Late irreversible move extension
+      if (   move == ttMove
+          && pos.rule50_count() > 80
+          && (captureOrPromotion || type_of(movedPiece) == PAWN))
+          extension = 2;
+
       // Add extension to new depth
       newDepth += extension;