Retire the misdesigned StepAttacks[] array.
[stockfish] / src / bitboard.cpp
index 3f05d8bee52fde649bb36d06a3df7814033aaec9..1f6dab9df64de1394d6784b6d84983cd378d5ead 100644 (file)
@@ -41,7 +41,6 @@ Bitboard FileBB[FILE_NB];
 Bitboard RankBB[RANK_NB];
 Bitboard AdjacentFilesBB[FILE_NB];
 Bitboard InFrontBB[COLOR_NB][RANK_NB];
-Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
 Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 Bitboard DistanceRingBB[SQUARE_NB][8];
@@ -49,6 +48,7 @@ Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
 Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
 Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
+Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
 
 namespace {
 
@@ -191,21 +191,25 @@ void Bitboards::init() {
               DistanceRingBB[s1][SquareDistance[s1][s2] - 1] |= s2;
           }
 
-  int steps[][9] = { {}, { 7, 9 }, { 17, 15, 10, 6, -6, -10, -15, -17 },
-                     {}, {}, {}, { 9, 7, -7, -9, 8, 1, -1, -8 } };
+  int steps[][5] = { {}, { 7, 9 }, { 6, 10, 15, 17 }, {}, {}, {}, { 1, 7, 8, 9 } };
 
   for (Color c = WHITE; c <= BLACK; ++c)
-      for (PieceType pt = PAWN; pt <= KING; ++pt)
+      for (PieceType pt : { PAWN, KNIGHT, KING })
           for (Square s = SQ_A1; s <= SQ_H8; ++s)
               for (int i = 0; steps[pt][i]; ++i)
               {
                   Square to = s + Square(c == WHITE ? steps[pt][i] : -steps[pt][i]);
 
                   if (is_ok(to) && distance(s, to) < 3)
-                      StepAttacksBB[make_piece(c, pt)][s] |= to;
+                  {
+                      if (pt == PAWN)
+                          PawnAttacks[c][s] |= to;
+                      else
+                          PseudoAttacks[pt][s] |= to;
+                  }
               }
 
-  Square RookDeltas[] = { NORTH,  EAST,  SOUTH,  WEST  };
+  Square RookDeltas[] = { NORTH,  EAST,  SOUTH,  WEST };
   Square BishopDeltas[] = { NORTH_EAST, SOUTH_EAST, SOUTH_WEST, NORTH_WEST };
 
   init_magics(RookTable, RookAttacks, RookMagics, RookMasks, RookShifts, RookDeltas, magic_index<ROOK>);
@@ -216,14 +220,14 @@ void Bitboards::init() {
       PseudoAttacks[QUEEN][s1]  = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
       PseudoAttacks[QUEEN][s1] |= PseudoAttacks[  ROOK][s1] = attacks_bb<  ROOK>(s1, 0);
 
-      for (Piece pc = W_BISHOP; pc <= W_ROOK; ++pc)
+      for (PieceType pt : { BISHOP, ROOK })
           for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
           {
-              if (!(PseudoAttacks[pc][s1] & s2))
+              if (!(PseudoAttacks[pt][s1] & s2))
                   continue;
 
-              LineBB[s1][s2] = (attacks_bb(pc, s1, 0) & attacks_bb(pc, s2, 0)) | s1 | s2;
-              BetweenBB[s1][s2] = attacks_bb(pc, s1, SquareBB[s2]) & attacks_bb(pc, s2, SquareBB[s1]);
+              LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
+              BetweenBB[s1][s2] = attacks_bb(pt, s1, SquareBB[s2]) & attacks_bb(pt, s2, SquareBB[s1]);
           }
   }
 }