simplify castling part of generate_all.

somewhat more compact, generates same code.

close https://github.com/official-stockfish/Stockfish/pull/2580

No functional change.

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 7e8961ae3b60603e35698c44277c2a6ed72656c6..9964ad343b8b656a6888938db3e17bed13c2ccc6 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -214,9 +214,6 @@ namespace {
 
   template<Color Us, GenType Type>
   ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) {
-
-    constexpr CastlingRights OO  = Us & KING_SIDE;
-    constexpr CastlingRights OOO = Us & QUEEN_SIDE;
     constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantations
 
     moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
@@ -232,14 +229,10 @@ namespace {
         while (b)
             *moveList++ = make_move(ksq, pop_lsb(&b));
 
-        if (Type != CAPTURES && pos.can_castle(CastlingRights(OO | OOO)))
-        {
-            if (!pos.castling_impeded(OO) && pos.can_castle(OO))
-                *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OO));
-
-            if (!pos.castling_impeded(OOO) && pos.can_castle(OOO))
-                *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OOO));
-        }
+        if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING))
+            for(CastlingRights cr : { Us & KING_SIDE, Us & QUEEN_SIDE } )
+                if (!pos.castling_impeded(cr) && pos.can_castle(cr))
+                    *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(cr));
     }
 
     return moveList;