X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=ba1b0072bce5079064b5f59cbe26328cb7b6dc03;hp=9aa3375026f6ee722ef256c5956bb840e47730cd;hb=28b6a457c24d9202ba43a6d6703221250f0f8749;hpb=6d24ef8585c2ed5618eb9b4ab1d8ee35a05ce2cd diff --git a/src/bitboard.h b/src/bitboard.h index 9aa33750..ba1b0072 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -39,6 +39,7 @@ const std::string pretty(Bitboard b); } +const Bitboard AllSquares = ~Bitboard(0); const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL; const Bitboard FileABB = 0x0101010101010101ULL; @@ -83,18 +84,18 @@ struct Magic { Bitboard* attacks; unsigned shift; - /// looks up the index using the 'magic bitboards' approach. + // Compute the attack's index using the 'magic bitboards' approach unsigned index(Bitboard occupied) const { - if (HasPext) - return unsigned(pext(occupied, mask)); + if (HasPext) + return unsigned(pext(occupied, mask)); - if (Is64Bit) - return unsigned(((occupied & mask) * magic) >> shift); + if (Is64Bit) + return unsigned(((occupied & mask) * magic) >> shift); - unsigned lo = unsigned(occupied) & unsigned(mask); - unsigned hi = unsigned(occupied >> 32) & unsigned(mask >> 32); - return (lo * unsigned(magic) ^ hi * unsigned(magic >> 32)) >> shift; + unsigned lo = unsigned(occupied) & unsigned(mask); + unsigned hi = unsigned(occupied >> 32) & unsigned(mask >> 32); + return (lo * unsigned(magic) ^ hi * unsigned(magic >> 32)) >> shift; } }; @@ -125,7 +126,7 @@ inline Bitboard& operator^=(Bitboard& b, Square s) { return b ^= SquareBB[s]; } -inline bool more_than_one(Bitboard b) { +constexpr bool more_than_one(Bitboard b) { return b & (b - 1); } @@ -153,7 +154,7 @@ inline Bitboard file_bb(Square s) { /// shift() moves a bitboard one step along direction D. Mainly for pawns template -inline Bitboard shift(Bitboard b) { +constexpr Bitboard shift(Bitboard b) { return D == NORTH ? b << 8 : D == SOUTH ? b >> 8 : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == SOUTH_EAST ? (b & ~FileHBB) >> 7 : D == NORTH_WEST ? (b & ~FileABB) << 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9 @@ -241,8 +242,8 @@ template<> inline int distance(Square x, Square y) { return distance(rank_ template inline Bitboard attacks_bb(Square s, Bitboard occupied) { - const Magic& M = Pt == ROOK ? RookMagics[s] : BishopMagics[s]; - return M.attacks[M.index(occupied)]; + const Magic& m = Pt == ROOK ? RookMagics[s] : BishopMagics[s]; + return m.attacks[m.index(occupied)]; } inline Bitboard attacks_bb(PieceType pt, Square s, Bitboard occupied) {