Use double rotate for magic generation

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index 867a7f0b947aa00c74f8bc2bf5734a79e63acecc..4613ec4d63eb87594c5c4127ddd6a1006710a72e 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -1778,7 +1778,7 @@ Value Position::compute_non_pawn_material(Color c) const {
 /// Position::is_draw() tests whether the position is drawn by material,
 /// repetition, or the 50 moves rule. It does not detect stalemates, this
 /// must be done by the search.
-
+template<bool SkipRepetition>
 bool Position::is_draw() const {
 
   // Draw by material?
@@ -1791,13 +1791,18 @@ bool Position::is_draw() const {
       return true;
 
   // Draw by repetition?
-  for (int i = 4, e = Min(Min(st->gamePly, st->rule50), st->pliesFromNull); i <= e; i += 2)
-      if (history[st->gamePly - i] == st->key)
-          return true;
+  if (!SkipRepetition)
+      for (int i = 4, e = Min(Min(st->gamePly, st->rule50), st->pliesFromNull); i <= e; i += 2)
+          if (history[st->gamePly - i] == st->key)
+              return true;
 
   return false;
 }
 
+// Explicit template instantiations
+template bool Position::is_draw<false>() const;
+template bool Position::is_draw<true>() const;
+
 
 /// Position::is_mate() returns true or false depending on whether the
 /// side to move is checkmated.