the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
+
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
extern const Bitboard RelativeRankBB[2][8];
extern const Bitboard InFrontBB[2][8];
-extern Bitboard SetMaskBB[64];
-extern Bitboard ClearMaskBB[64];
+extern Bitboard SetMaskBB[65];
+extern Bitboard ClearMaskBB[65];
extern Bitboard StepAttackBB[16][64];
extern Bitboard RayBB[64][8];
}
+/// behind_bb() takes a color and a rank or square as input, and returns a
+/// bitboard representing all the squares on all ranks behind of the rank
+/// (or square), from the given color's point of view.
+
+inline Bitboard behind_bb(Color c, Rank r) {
+ return InFrontBB[opposite_color(c)][r];
+}
+
+inline Bitboard behind_bb(Color c, Square s) {
+ return in_front_bb(opposite_color(c), square_rank(s));
+}
+
+
/// ray_bb() gives a bitboard representing all squares along the ray in a
/// given direction from a given square.
unsigned w = unsigned(b >> 32), v = unsigned(b);
v = v - ((v >> 1) & 0x55555555);
w = w - ((w >> 1) & 0x55555555);
+ v += w;
v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
- w = (w & 0x33333333) + ((w >> 2) & 0x33333333);
v = (v + (v >> 4)) & 0x0F0F0F0F;
- w = (w + (w >> 4)) & 0x0F0F0F0F;
- v = ((v+w) * 0x01010101) >> 24; // mul is fast on amd procs
+ v = (v * 0x01010101) >> 24; // mul is fast on amd procs
return int(v);
}
unsigned w = unsigned(b >> 32), v = unsigned(b);
v = v - ((v >> 1) & 0x55555555);
w = w - ((w >> 1) & 0x55555555);
+ v += w;
v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
- w = (w & 0x33333333) + ((w >> 2) & 0x33333333);
- v = ((v+w) * 0x11111111) >> 28;
+ v = (v * 0x11111111) >> 28;
return int(v);
}