simplify opposite_colors

diff --git a/src/bitboard.h b/src/bitboard.h
index c6dbc64..f8440a2 100644 (file)
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -135,6 +135,10 @@ constexpr bool more_than_one(Bitboard b) {
   return b & (b - 1);
 }
 
+inline bool opposite_colors(Square s1, Square s2) {
+  return bool(DarkSquares & s1) != bool(DarkSquares & s2);
+}
+
 /// rank_bb() and file_bb() return a bitboard representing all the squares on
 /// the given file or rank.
 

diff --git a/src/types.h b/src/types.h
index 3b5afec..c4c2752 100644 (file)
--- a/src/types.h
+++ b/src/types.h
@@ -413,11 +413,6 @@ constexpr Rank relative_rank(Color c, Square s) {
   return relative_rank(c, rank_of(s));
 }
 
-inline bool opposite_colors(Square s1, Square s2) {
-  int s = int(s1) ^ int(s2);
-  return ((s >> 3) ^ s) & 1;
-}
-
 constexpr Direction pawn_push(Color c) {
   return c == WHITE ? NORTH : SOUTH;
 }