bool move_is_legal(const Position& pos, const Move m) {
- MoveStack mlist[256];
+ MoveStack mlist[MOVES_MAX];
MoveStack *cur, *last = generate_moves(pos, mlist, true);
for (cur = mlist; cur != last; cur++)
Piece pc = pos.piece_on(from);
// Use a slower but simpler function for uncommon cases
- if (move_is_ep(m) || move_is_castle(m))
+ if (move_is_special(m))
return move_is_legal(pos, m);
// If the from square is not occupied by a piece belonging to the side to
if ((us == WHITE) != (direction > 0))
return false;
- // A pawn move is a promotion iff the destination square is
- // on the 8/1th rank.
- if (( (square_rank(to) == RANK_8 && us == WHITE)
- ||(square_rank(to) == RANK_1 && us != WHITE)) != bool(move_is_promotion(m)))
- return false;
-
- // The promotion piece, if any, must be valid
- if (move_promotion_piece(m) > QUEEN || move_promotion_piece(m) == PAWN)
+ // We have already handled promotion moves, so destination
+ // cannot be on the 8/1th rank.
+ if (square_rank(to) == RANK_8 || square_rank(to) == RANK_1)
return false;
// Proceed according to the square delta between the origin and
default:
return false;
}
- // The move is pseudo-legal, check if it is also legal
- return pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned);
}
+ else if (!bit_is_set(pos.attacks_from(pc, from), to))
+ return false;
- // Luckly we can handle all the other pieces in one go
- return bit_is_set(pos.attacks_from(pc, from), to)
- && (pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned))
- && !move_is_promotion(m);
+ // The move is pseudo-legal, check if it is also legal
+ return pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned);
}
Square from;
const Square* ptr = pos.piece_list_begin(us, Piece);
- while ((from = *ptr++) != SQ_NONE)
+ if (*ptr != SQ_NONE)
{
- b = pos.attacks_from<Piece>(from) & target;
- SERIALIZE_MOVES(b);
+ do {
+ from = *ptr;
+ b = pos.attacks_from<Piece>(from) & target;
+ SERIALIZE_MOVES(b);
+ } while (*++ptr != SQ_NONE);
}
return mlist;
}
return mlist;
}
- template<Color Us, SquareDelta Direction>
+ template<SquareDelta Delta>
inline Bitboard move_pawns(Bitboard p) {
- if (Direction == DELTA_N)
- return Us == WHITE ? p << 8 : p >> 8;
- else if (Direction == DELTA_NE)
- return Us == WHITE ? p << 9 : p >> 7;
- else if (Direction == DELTA_NW)
- return Us == WHITE ? p << 7 : p >> 9;
- else
- return p;
+ return Delta == DELTA_N ? p << 8 : Delta == DELTA_S ? p >> 8 :
+ Delta == DELTA_NE ? p << 9 : Delta == DELTA_SE ? p >> 7 :
+ Delta == DELTA_NW ? p << 7 : Delta == DELTA_SW ? p >> 9 : p;
}
- template<Color Us, MoveType Type, SquareDelta Diagonal>
- inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces) {
+ template<Color Us, MoveType Type, SquareDelta Delta>
+ inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
// Calculate our parametrized parameters at compile time
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
- const Bitboard TFileABB = (Diagonal == DELTA_NE ? FileABB : FileHBB);
- const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
- const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
- const SquareDelta TTDELTA_NE = (Diagonal == DELTA_NE ? TDELTA_NE : TDELTA_NW);
+ const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
Bitboard b1, b2;
Square to;
// Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black)
- b1 = move_pawns<Us, Diagonal>(pawns) & ~TFileABB & enemyPieces;
+ b1 = move_pawns<Delta>(pawns) & ~TFileABB & target;
// Capturing promotions and under-promotions
if (b1 & TRank8BB)
to = pop_1st_bit(&b2);
if (Type == CAPTURE || Type == EVASION)
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+ (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN);
if (Type == NON_CAPTURE || Type == EVASION)
{
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, KNIGHT);
+ (*mlist++).move = make_promotion_move(to - Delta, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - Delta, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
}
// This is the only possible under promotion that can give a check
// not already included in the queen-promotion. It is not sure that
// the promoted knight will give check, but it doesn't worth to verify.
if (Type == CHECK)
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, KNIGHT);
+ (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
}
}
// Serialize standard captures
if (Type == CAPTURE || Type == EVASION)
- SERIALIZE_MOVES_D(b1, -TTDELTA_NE);
+ SERIALIZE_MOVES_D(b1, -Delta);
return mlist;
}
const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
+ const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
+ const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
+ const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
Square to;
Bitboard b1, b2, enemyPieces, emptySquares;
if (Type == EVASION)
enemyPieces &= target; // Capture only the checker piece
- mlist = generate_pawn_captures<Us, Type, DELTA_NE>(mlist, pawns, enemyPieces);
- mlist = generate_pawn_captures<Us, Type, DELTA_NW>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures<Us, Type, TDELTA_NE>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures<Us, Type, TDELTA_NW>(mlist, pawns, enemyPieces);
}
// Non-capturing promotions and underpromotions
if (pawns & TRank7BB)
{
- b1 = move_pawns<Us, DELTA_N>(pawns) & TRank8BB & pos.empty_squares();
+ b1 = move_pawns<TDELTA_N>(pawns) & TRank8BB & pos.empty_squares();
if (Type == EVASION)
b1 &= target; // Only blocking promotion pushes
emptySquares = (Type == NON_CAPTURE ? target : pos.empty_squares());
// Single and double pawn pushes
- b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
- b2 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
+ b1 = move_pawns<TDELTA_N>(pawns) & emptySquares & ~TRank8BB;
+ b2 = move_pawns<TDELTA_N>(b1 & TRank3BB) & emptySquares;
// Filter out unwanted pushes according to the move type
if (Type == EVASION)
// don't generate captures.
if (pawns & target) // For CHECK type target is dc bitboard
{
- Bitboard dc1 = move_pawns<Us, DELTA_N>(pawns & target & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
- Bitboard dc2 = move_pawns<Us, DELTA_N>(dc1 & TRank3BB) & emptySquares;
+ Bitboard dc1 = move_pawns<TDELTA_N>(pawns & target & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
+ Bitboard dc2 = move_pawns<TDELTA_N>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;