X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=b1d961f4d9fc2b018a9084e66510004b7594a779;hp=77986638bc7bb5ab39daffd2b75db86ed2acdd8b;hb=f98c77413b68d506977bc078de7a47455968a926;hpb=82ad9ce9cfb0eff33f1d781f329f7c5dc0b277eb

diff --git a/src/bitboard.h b/src/bitboard.h
index 77986638..b1d961f4 100644
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -68,7 +68,6 @@ constexpr Bitboard Center      = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
 extern uint8_t PopCnt16[1 << 16];
 extern uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
-extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard DistanceRingBB[SQUARE_NB][8];
 extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
@@ -185,13 +184,12 @@ inline Bitboard adjacent_files_bb(File f) {
 }
 
 
-/// between_bb() returns a bitboard representing all the squares between the two
-/// given ones. For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with
-/// the bits for square d5 and e6 set. If s1 and s2 are not on the same rank,
-/// file or diagonal, 0 is returned.
+/// between_bb() returns squares that are linearly between the given squares
+/// If the given squares are not on a same file/rank/diagonal, return 0.
 
 inline Bitboard between_bb(Square s1, Square s2) {
-  return BetweenBB[s1][s2];
+  return LineBB[s1][s2] & ( (AllSquares << (s1 +  (s1 < s2)))
+                           ^(AllSquares << (s2 + !(s1 < s2))));
 }