Rewrite some bitboard init code

[stockfish] / src / bitboard.h

diff --git a/src/bitboard.h b/src/bitboard.h
index e0e2fe64545ececedd4acf53852b9fd7e3b7dbf0..349005787fd402d6ab958818f46e1262fc4b8356 100644 (file)
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -74,6 +74,7 @@ extern Bitboard AdjacentFilesBB[FILE_NB];
 extern Bitboard InFrontBB[COLOR_NB][RANK_NB];
 extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
 extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
+extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard DistanceRingsBB[SQUARE_NB][8];
 extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
 extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
@@ -222,12 +223,11 @@ inline Bitboard squares_of_color(Square s) {
 }
 
 
-/// squares_aligned() returns true if the squares s1, s2 and s3 are aligned
+/// aligned() returns true if the squares s1, s2 and s3 are aligned
 /// either on a straight or on a diagonal line.
 
-inline bool squares_aligned(Square s1, Square s2, Square s3) {
-  return  (BetweenBB[s1][s2] | BetweenBB[s1][s3] | BetweenBB[s2][s3])
-        & (     SquareBB[s1] |      SquareBB[s2] |      SquareBB[s3]);
+inline bool aligned(Square s1, Square s2, Square s3) {
+  return LineBB[s1][s2] & s3;
 }
 
 
@@ -254,6 +254,16 @@ inline Bitboard attacks_bb(Square s, Bitboard occ) {
   return (Pt == ROOK ? RAttacks : BAttacks)[s][magic_index<Pt>(s, occ)];
 }
 
+inline Bitboard attacks_bb(Piece p, Square s, Bitboard occ) {
+
+  switch (type_of(p))
+  {
+  case BISHOP: return attacks_bb<BISHOP>(s, occ);
+  case ROOK  : return attacks_bb<ROOK>(s, occ);
+  case QUEEN : return attacks_bb<BISHOP>(s, occ) | attacks_bb<ROOK>(s, occ);
+  default    : return StepAttacksBB[p][s];
+  }
+}
 
 /// lsb()/msb() finds the least/most significant bit in a nonzero bitboard.
 /// pop_lsb() finds and clears the least significant bit in a nonzero bitboard.
@@ -319,9 +329,10 @@ extern Square pop_lsb(Bitboard* b);
 
 #endif
 
-/// lsb() overload finds least significant bit relative to the given color
-inline Square lsb(Color c, Bitboard b) {
-  return c == WHITE ? lsb(b) : msb(b);
-}
+/// frontmost_sq() and backmost_sq() find the square corresponding to the
+/// most/least advanced bit relative to the given color.
+
+inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); }
+inline Square  backmost_sq(Color c, Bitboard b) { return c == WHITE ? lsb(b) : msb(b); }
 
 #endif // #ifndef BITBOARD_H_INCLUDED