X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=41b85f074ae0994a86c6615707ad03bb5be925b2;hp=2a57605e164fa0ceeb5c34f2e26bce6cc2af8a5b;hb=0a1092f64eb9eb232094036086fc5c98ed1f3c46;hpb=53ab32ef0b6e47d8d962f8c1fccd32d3c22f138c

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 2a57605e..41b85f07 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -233,15 +233,15 @@ void MovePicker::generate_next() {
       killers[2].move = killers[3].move = MOVE_NONE;
       killers[4].move = killers[5].move = MOVE_NONE;
 
+      // Please note that following code is racy and could yield to rare (less
+      // than 1 out of a million) duplicated entries in SMP case. This is harmless.
+
       // Be sure countermoves are different from killers
       for (int i = 0; i < 2; ++i)
           if (   countermoves[i] != (cur+0)->move
               && countermoves[i] != (cur+1)->move)
               (end++)->move = countermoves[i];
 
-      if (countermoves[1] && countermoves[1] == countermoves[0]) // Due to SMP races
-          killers[3].move = MOVE_NONE;
-
       // Be sure followupmoves are different from killers and countermoves
       for (int i = 0; i < 2; ++i)
           if (   followupmoves[i] != (cur+0)->move
@@ -249,10 +249,6 @@ void MovePicker::generate_next() {
               && followupmoves[i] != (cur+2)->move
               && followupmoves[i] != (cur+3)->move)
               (end++)->move = followupmoves[i];
-
-      if (followupmoves[1] && followupmoves[1] == followupmoves[0]) // Due to SMP races
-          (--end)->move = MOVE_NONE;
-
       return;
 
   case QUIETS_1_S1:
@@ -300,7 +296,7 @@ void MovePicker::generate_next() {
 /// next_move() is the most important method of the MovePicker class. It returns
 /// a new pseudo legal move every time it is called, until there are no more moves
 /// left. It picks the move with the biggest score from a list of generated moves
-/// taking care not returning the ttMove if it has already been searched previously.
+/// taking care not to return the ttMove if it has already been searched.
 template<>
 Move MovePicker::next_move<false>() {