Remove BetweenBB Array #2076

Non functional change.

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 2adf27794209a4e89d175eca412453a2beda2f48..94dfa70ff2197274e3349f6b01aeb8a154e8aa2a 100644 (file)
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -27,7 +27,6 @@
 uint8_t PopCnt16[1 << 16];
 uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
 uint8_t PopCnt16[1 << 16];
 uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 

-Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];

 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 Bitboard DistanceRingBB[SQUARE_NB][8];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 Bitboard DistanceRingBB[SQUARE_NB][8];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];


@@ -121,10 +120,7 @@ void Bitboards::init() {
       for (PieceType pt : { BISHOP, ROOK })
           for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
               if (PseudoAttacks[pt][s1] & s2)
       for (PieceType pt : { BISHOP, ROOK })
           for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
               if (PseudoAttacks[pt][s1] & s2)

-              {

                   LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
                   LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;

-                  BetweenBB[s1][s2] = attacks_bb(pt, s1, square_bb(s2)) & attacks_bb(pt, s2, square_bb(s1));
-              }

   }
 }
 
   }
 }
 

diff --git a/src/bitboard.h b/src/bitboard.h
index 77986638bc7bb5ab39daffd2b75db86ed2acdd8b..b1d961f4d9fc2b018a9084e66510004b7594a779 100644 (file)
--- 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 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];
 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) {
 
 inline Bitboard between_bb(Square s1, Square s2) {

-  return BetweenBB[s1][s2];
+  return LineBB[s1][s2] & ( (AllSquares << (s1 +  (s1 < s2)))
+                           ^(AllSquares << (s2 + !(s1 < s2))));

 }
 
 
 }