along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-////
-//// Includes
-////
-
#include <cassert>
#include "bitcount.h"
#include "movegen.h"
+#include "position.h"
// Simple macro to wrap a very common while loop, no facny, no flexibility,
// hardcoded list name 'mlist' and from square 'from'.
// Version used for pawns, where the 'from' square is given as a delta from the 'to' square
#define SERIALIZE_MOVES_D(b, d) while (b) { to = pop_1st_bit(&b); (*mlist++).move = make_move(to + (d), to); }
-////
-//// Local definitions
-////
-
namespace {
enum CastlingSide {
QUEEN_SIDE
};
- enum MoveType {
- CAPTURE,
- NON_CAPTURE,
- CHECK,
- EVASION
- };
+ template<CastlingSide>
+ MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us);
- // Helper templates
- template<CastlingSide Side>
- MoveStack* generate_castle_moves(const Position&, MoveStack*);
-
- template<Color Us, MoveType Type>
+ template<Color, MoveType>
MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square);
- // Template generate_piece_moves (captures and non-captures) with specializations and overloads
- template<PieceType>
- MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard);
+ template<PieceType Pt>
+ inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) {
- template<>
- MoveStack* generate_piece_moves<KING>(const Position&, MoveStack*, Color, Bitboard);
+ assert(Pt != QUEEN);
+ assert(Pt != PAWN);
- template<PieceType Piece, MoveType Type>
- inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
+ Bitboard b = pos.attacks_from<Pt>(from) & pos.empty_squares();
- assert(Piece == PAWN);
- assert(Type == CAPTURE || Type == NON_CAPTURE || Type == EVASION);
+ if (Pt == KING)
+ b &= ~QueenPseudoAttacks[pos.king_square(opposite_color(pos.side_to_move()))];
- return (us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m, t, SQ_NONE)
- : generate_pawn_moves<BLACK, Type>(p, m, t, SQ_NONE));
+ SERIALIZE_MOVES(b);
+ return mlist;
}
- // Templates for non-capture checks generation
+ template<PieceType Pt>
+ inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
+ Bitboard dc, Square ksq) {
+ assert(Pt != KING);
+ assert(Pt != PAWN);
- template<PieceType Piece>
- MoveStack* generate_discovered_checks(const Position&, MoveStack*, Square);
+ Bitboard checkSqs, b;
+ Square from;
+ const Square* pl = pos.piece_list(us, Pt);
- template<PieceType>
- MoveStack* generate_direct_checks(const Position&, MoveStack*, Color, Bitboard, Square);
+ if ((from = *pl++) == SQ_NONE)
+ return mlist;
- template<>
- inline MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
+ checkSqs = pos.attacks_from<Pt>(ksq) & pos.empty_squares();
- return (us == WHITE ? generate_pawn_moves<WHITE, CHECK>(p, m, dc, ksq)
- : generate_pawn_moves<BLACK, CHECK>(p, m, dc, ksq));
- }
-}
+ do
+ {
+ if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
+ || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs))
+ || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
+ continue;
+ if (dc && bit_is_set(dc, from))
+ continue;
-////
-//// Functions
-////
+ b = pos.attacks_from<Pt>(from) & checkSqs;
+ SERIALIZE_MOVES(b);
+ } while ((from = *pl++) != SQ_NONE);
-/// generate_captures() generates all pseudo-legal captures and queen
-/// promotions. Returns a pointer to the end of the move list.
+ return mlist;
+ }
-MoveStack* generate_captures(const Position& pos, MoveStack* mlist) {
+ template<>
+ FORCE_INLINE MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
- assert(pos.is_ok());
- assert(!pos.is_check());
+ return (us == WHITE ? generate_pawn_moves<WHITE, MV_CHECK>(p, m, dc, ksq)
+ : generate_pawn_moves<BLACK, MV_CHECK>(p, m, dc, ksq));
+ }
- Color us = pos.side_to_move();
- Bitboard target = pos.pieces_of_color(opposite_color(us));
+ template<PieceType Pt, MoveType Type>
+ FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
- mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
- mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
- mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
- mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
- mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us, target);
- return generate_piece_moves<KING>(pos, mlist, us, target);
-}
+ assert(Pt == PAWN);
+ assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_EVASION);
+ return (us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m, t, SQ_NONE)
+ : generate_pawn_moves<BLACK, Type>(p, m, t, SQ_NONE));
+ }
-/// generate_noncaptures() generates all pseudo-legal non-captures and
-/// underpromotions. Returns a pointer to the end of the move list.
+ template<PieceType Pt>
+ FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
-MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) {
+ Bitboard b;
+ Square from;
+ const Square* pl = pos.piece_list(us, Pt);
- assert(pos.is_ok());
- assert(!pos.is_check());
+ if (*pl != SQ_NONE)
+ {
+ do {
+ from = *pl;
+ b = pos.attacks_from<Pt>(from) & target;
+ SERIALIZE_MOVES(b);
+ } while (*++pl != SQ_NONE);
+ }
+ return mlist;
+ }
- Color us = pos.side_to_move();
- Bitboard target = pos.empty_squares();
+ template<>
+ FORCE_INLINE MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+
+ Bitboard b;
+ Square from = pos.king_square(us);
+
+ b = pos.attacks_from<KING>(from) & target;
+ SERIALIZE_MOVES(b);
+ return mlist;
+ }
- mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us, target);
- mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
- mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
- mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
- mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
- mlist = generate_piece_moves<KING>(pos, mlist, us, target);
- mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
- return generate_castle_moves<QUEEN_SIDE>(pos, mlist);
}
-/// generate_non_evasions() generates all pseudo-legal captures and
+/// generate<MV_CAPTURE> generates all pseudo-legal captures and queen
+/// promotions. Returns a pointer to the end of the move list.
+///
+/// generate<MV_NON_CAPTURE> generates all pseudo-legal non-captures and
+/// underpromotions. Returns a pointer to the end of the move list.
+///
+/// generate<MV_NON_EVASION> generates all pseudo-legal captures and
/// non-captures. Returns a pointer to the end of the move list.
-MoveStack* generate_non_evasions(const Position& pos, MoveStack* mlist) {
+template<MoveType Type>
+MoveStack* generate(const Position& pos, MoveStack* mlist) {
- assert(pos.is_ok());
- assert(!pos.is_check());
+ assert(!pos.in_check());
Color us = pos.side_to_move();
- Bitboard target = pos.pieces_of_color(opposite_color(us));
+ Bitboard target;
- mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us, target);
- mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us, pos.empty_squares());
+ if (Type == MV_CAPTURE || Type == MV_NON_EVASION)
+ target = pos.pieces(opposite_color(us));
+ else if (Type == MV_NON_CAPTURE)
+ target = pos.empty_squares();
+ else
+ assert(false);
- target |= pos.empty_squares();
+ if (Type == MV_NON_EVASION)
+ {
+ mlist = generate_piece_moves<PAWN, MV_CAPTURE>(pos, mlist, us, target);
+ mlist = generate_piece_moves<PAWN, MV_NON_CAPTURE>(pos, mlist, us, pos.empty_squares());
+ target |= pos.empty_squares();
+ }
+ else
+ mlist = generate_piece_moves<PAWN, Type>(pos, mlist, us, target);
mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
mlist = generate_piece_moves<KING>(pos, mlist, us, target);
- mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
- return generate_castle_moves<QUEEN_SIDE>(pos, mlist);
+
+ if (Type != MV_CAPTURE && pos.can_castle(us))
+ {
+ if (pos.can_castle(us == WHITE ? WHITE_OO : BLACK_OO))
+ mlist = generate_castle_moves<KING_SIDE>(pos, mlist, us);
+
+ if (pos.can_castle(us == WHITE ? WHITE_OOO : BLACK_OOO))
+ mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist, us);
+ }
+
+ return mlist;
}
+// Explicit template instantiations
+template MoveStack* generate<MV_CAPTURE>(const Position& pos, MoveStack* mlist);
+template MoveStack* generate<MV_NON_CAPTURE>(const Position& pos, MoveStack* mlist);
+template MoveStack* generate<MV_NON_EVASION>(const Position& pos, MoveStack* mlist);
+
/// generate_non_capture_checks() generates all pseudo-legal non-captures and knight
/// underpromotions that give check. Returns a pointer to the end of the move list.
+template<>
+MoveStack* generate<MV_NON_CAPTURE_CHECK>(const Position& pos, MoveStack* mlist) {
-MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist) {
-
- assert(pos.is_ok());
- assert(!pos.is_check());
+ assert(!pos.in_check());
Bitboard b, dc;
Square from;
Color us = pos.side_to_move();
Square ksq = pos.king_square(opposite_color(us));
- assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING));
+ assert(pos.piece_on(ksq) == make_piece(opposite_color(us), KING));
// Discovered non-capture checks
- b = dc = pos.discovered_check_candidates(us);
+ b = dc = pos.discovered_check_candidates();
while (b)
{
from = pop_1st_bit(&b);
- switch (pos.type_of_piece_on(from))
+ switch (piece_type(pos.piece_on(from)))
{
case PAWN: /* Will be generated togheter with pawns direct checks */ break;
case KNIGHT: mlist = generate_discovered_checks<KNIGHT>(pos, mlist, from); break;
/// generate_evasions() generates all pseudo-legal check evasions when
/// the side to move is in check. Returns a pointer to the end of the move list.
+template<>
+MoveStack* generate<MV_EVASION>(const Position& pos, MoveStack* mlist) {
-MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) {
-
- assert(pos.is_ok());
- assert(pos.is_check());
+ assert(pos.in_check());
Bitboard b, target;
Square from, checksq;
Bitboard checkers = pos.checkers();
Bitboard sliderAttacks = EmptyBoardBB;
- assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING));
+ assert(pos.piece_on(ksq) == make_piece(us, KING));
assert(checkers);
// Find squares attacked by slider checkers, we will remove
checkersCnt++;
checksq = pop_1st_bit(&b);
- assert(pos.color_of_piece_on(checksq) == opposite_color(us));
+ assert(piece_color(pos.piece_on(checksq)) == opposite_color(us));
- switch (pos.type_of_piece_on(checksq))
+ switch (piece_type(pos.piece_on(checksq)))
{
case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break;
case ROOK: sliderAttacks |= RookPseudoAttacks[checksq]; break;
case QUEEN:
- // In case of a queen remove also squares attacked in the other direction to
- // avoid possible illegal moves when queen and king are on adjacent squares.
- if (direction_is_straight(checksq, ksq))
- sliderAttacks |= RookPseudoAttacks[checksq] | pos.attacks_from<BISHOP>(checksq);
+ // If queen and king are far we can safely remove all the squares attacked
+ // in the other direction becuase are not reachable by the king anyway.
+ if (squares_between(ksq, checksq) || (RookPseudoAttacks[checksq] & (1ULL << ksq)))
+ sliderAttacks |= QueenPseudoAttacks[checksq];
+
+ // Otherwise, if king and queen are adjacent and on a diagonal line, we need to
+ // use real rook attacks to check if king is safe to move in the other direction.
+ // For example: king in B2, queen in A1 a knight in B1, and we can safely move to C1.
else
sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from<ROOK>(checksq);
+
default:
break;
}
} while (b);
// Generate evasions for king, capture and non capture moves
- b = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
+ b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
from = ksq;
SERIALIZE_MOVES(b);
// checker piece is possible.
target = squares_between(checksq, ksq) | checkers;
- mlist = generate_piece_moves<PAWN, EVASION>(pos, mlist, us, target);
+ mlist = generate_piece_moves<PAWN, MV_EVASION>(pos, mlist, us, target);
mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
}
-/// generate_moves() computes a complete list of legal or pseudo-legal moves in
-/// the current position. This function is not very fast, and should be used
-/// only in non time-critical paths.
-
-MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal) {
+/// generate<MV_LEGAL> computes a complete list of legal moves in the current position
- assert(pos.is_ok());
+template<>
+MoveStack* generate<MV_LEGAL>(const Position& pos, MoveStack* mlist) {
MoveStack *last, *cur = mlist;
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ Bitboard pinned = pos.pinned_pieces();
- // Generate pseudo-legal moves
- last = pos.is_check() ? generate_evasions(pos, mlist)
- : generate_non_evasions(pos, mlist);
- if (pseudoLegal)
- return last;
+ last = pos.in_check() ? generate<MV_EVASION>(pos, mlist)
+ : generate<MV_NON_EVASION>(pos, mlist);
// Remove illegal moves from the list
while (cur != last)
- if (pos.pl_move_is_legal(cur->move, pinned))
- cur++;
- else
+ if (!pos.pl_move_is_legal(cur->move, pinned))
cur->move = (--last)->move;
+ else
+ cur++;
return last;
}
-/// move_is_legal() takes a position and a (not necessarily pseudo-legal)
-/// move and tests whether the move is legal. This version is not very fast
-/// and should be used only in non time-critical paths.
-
-bool move_is_legal(const Position& pos, const Move m) {
-
- MoveStack mlist[256];
- MoveStack *cur, *last = generate_moves(pos, mlist, true);
-
- for (cur = mlist; cur != last; cur++)
- if (cur->move == m)
- return pos.pl_move_is_legal(m, pos.pinned_pieces(pos.side_to_move()));
-
- return false;
-}
-
-
-/// Fast version of move_is_legal() that takes a position a move and a
-/// bitboard of pinned pieces as input, and tests whether the move is legal.
-
-bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
-
- assert(pos.is_ok());
- assert(move_is_ok(m));
- assert(pinned == pos.pinned_pieces(pos.side_to_move()));
-
- Color us = pos.side_to_move();
- Color them = opposite_color(us);
- Square from = move_from(m);
- Square to = move_to(m);
- Piece pc = pos.piece_on(from);
-
- // Use a slower but simpler function for uncommon cases
- 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
- // move, the move is obviously not legal.
- if (color_of_piece(pc) != us)
- return false;
-
- // The destination square cannot be occupied by a friendly piece
- if (pos.color_of_piece_on(to) == us)
- return false;
-
- // Handle the special case of a pawn move
- if (type_of_piece(pc) == PAWN)
- {
- // Move direction must be compatible with pawn color
- int direction = to - from;
- if ((us == WHITE) != (direction > 0))
- return false;
-
- // 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
- // destination squares.
- switch (direction)
- {
- case DELTA_NW:
- case DELTA_NE:
- case DELTA_SW:
- case DELTA_SE:
- // Capture. The destination square must be occupied by an enemy
- // piece (en passant captures was handled earlier).
- if (pos.color_of_piece_on(to) != them)
- return false;
- break;
-
- case DELTA_N:
- case DELTA_S:
- // Pawn push. The destination square must be empty.
- if (!pos.square_is_empty(to))
- return false;
- break;
-
- case DELTA_NN:
- // Double white pawn push. The destination square must be on the fourth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if ( square_rank(to) != RANK_4
- || !pos.square_is_empty(to)
- || !pos.square_is_empty(from + DELTA_N))
- return false;
- break;
-
- case DELTA_SS:
- // Double black pawn push. The destination square must be on the fifth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if ( square_rank(to) != RANK_5
- || !pos.square_is_empty(to)
- || !pos.square_is_empty(from + DELTA_S))
- return false;
- break;
-
- default:
- return false;
- }
- }
- else if (!bit_is_set(pos.attacks_from(pc, from), to))
- 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);
-}
-
-
namespace {
- template<PieceType Piece>
- MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
-
- Bitboard b;
- Square from;
- const Square* ptr = pos.piece_list_begin(us, Piece);
+ template<Square Delta>
+ inline Bitboard move_pawns(Bitboard p) {
- if (*ptr != SQ_NONE)
- {
- do {
- from = *ptr;
- b = pos.attacks_from<Piece>(from) & target;
- SERIALIZE_MOVES(b);
- } while (*++ptr != SQ_NONE);
- }
- return mlist;
+ 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<>
- MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+ template<MoveType Type, Square Delta>
+ inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
+
+ const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
Bitboard b;
- Square from = pos.king_square(us);
+ Square to;
- b = pos.attacks_from<KING>(from) & target;
- SERIALIZE_MOVES(b);
+ // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black)
+ b = move_pawns<Delta>(pawns) & target & ~TFileABB;
+ SERIALIZE_MOVES_D(b, -Delta);
return mlist;
}
- template<Color Us, SquareDelta Direction>
- 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;
- }
-
- template<Color Us, MoveType Type, SquareDelta Diagonal>
- inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces) {
+ template<MoveType Type, Square Delta>
+ inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, 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;
+ Bitboard b;
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;
+ // Promotions and under-promotions, both captures and non-captures
+ b = move_pawns<Delta>(pawnsOn7) & target;
- // Capturing promotions and under-promotions
- if (b1 & TRank8BB)
- {
- b2 = b1 & TRank8BB;
- b1 &= ~TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
+ if (Delta != DELTA_N && Delta != DELTA_S)
+ b &= ~TFileABB;
- if (Type == CAPTURE || Type == EVASION)
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+ while (b)
+ {
+ to = pop_1st_bit(&b);
- 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);
- }
+ if (Type == MV_CAPTURE || Type == MV_EVASION)
+ (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN);
- // 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);
+ if (Type == MV_NON_CAPTURE || Type == MV_EVASION)
+ {
+ (*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);
}
- }
-
- // Serialize standard captures
- if (Type == CAPTURE || Type == EVASION)
- SERIALIZE_MOVES_D(b1, -TTDELTA_NE);
+ // This is the only possible under promotion that can give a check
+ // not already included in the queen-promotion.
+ if ( Type == MV_CHECK
+ && bit_is_set(pos.attacks_from<KNIGHT>(to), pos.king_square(Delta > 0 ? BLACK : WHITE)))
+ (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
+ else (void)pos; // Silence a warning under MSVC
+ }
return mlist;
}
template<Color Us, MoveType Type>
MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq) {
- // Calculate our parametrized parameters at compile time
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- 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);
+ // Calculate our parametrized parameters at compile time, named
+ // according to the point of view of white side.
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+ const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ const Square UP = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square RIGHT_UP = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Square LEFT_UP = (Us == WHITE ? DELTA_NW : DELTA_SE);
Square to;
- Bitboard b1, b2, enemyPieces, emptySquares;
+ Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares;
Bitboard pawns = pos.pieces(PAWN, Us);
+ Bitboard pawnsOn7 = pawns & TRank7BB;
+ Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces(Them));
- // Standard captures and capturing promotions and underpromotions
- if (Type == CAPTURE || Type == EVASION || (pawns & TRank7BB))
+ // Pre-calculate pawn pushes before changing emptySquares definition
+ if (Type != MV_CAPTURE)
{
- enemyPieces = (Type == CAPTURE ? target : pos.pieces_of_color(opposite_color(Us)));
-
- 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);
+ emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares());
+ pawnPushes = move_pawns<UP>(pawns & ~TRank7BB) & emptySquares;
}
- // Non-capturing promotions and underpromotions
- if (pawns & TRank7BB)
+ if (Type == MV_EVASION)
{
- b1 = move_pawns<Us, DELTA_N>(pawns) & TRank8BB & pos.empty_squares();
-
- if (Type == EVASION)
- b1 &= target; // Only blocking promotion pushes
-
- while (b1)
- {
- to = pop_1st_bit(&b1);
-
- if (Type == CAPTURE || Type == EVASION)
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ emptySquares &= target; // Only blocking squares
+ enemyPieces &= target; // Capture only the checker piece
+ }
- if (Type == NON_CAPTURE || Type == EVASION)
- {
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
- }
+ // Promotions and underpromotions
+ if (pawnsOn7)
+ {
+ if (Type == MV_CAPTURE)
+ emptySquares = pos.empty_squares();
- // This is the only possible under promotion that can give a check
- // not already included in the queen-promotion.
- if (Type == CHECK && bit_is_set(pos.attacks_from<KNIGHT>(to), pos.king_square(Them)))
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
- }
+ pawns &= ~TRank7BB;
+ mlist = generate_promotions<Type, RIGHT_UP>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Type, LEFT_UP>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Type, UP>(pos, mlist, pawnsOn7, emptySquares);
}
- // Standard pawn pushes and double pushes
- if (Type != CAPTURE)
+ // Standard captures
+ if (Type == MV_CAPTURE || Type == MV_EVASION)
{
- emptySquares = (Type == NON_CAPTURE ? target : pos.empty_squares());
+ mlist = generate_pawn_captures<Type, RIGHT_UP>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures<Type, LEFT_UP>(mlist, pawns, enemyPieces);
+ }
- // Single and double pawn pushes
- b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
- b2 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
+ // Single and double pawn pushes
+ if (Type != MV_CAPTURE)
+ {
+ b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares);
+ b2 = move_pawns<UP>(pawnPushes & TRank3BB) & emptySquares;
- // Filter out unwanted pushes according to the move type
- if (Type == EVASION)
- {
- b1 &= target;
- b2 &= target;
- }
- else if (Type == CHECK)
+ if (Type == MV_CHECK)
{
- // Pawn moves which give direct cheks
+ // Consider only pawn moves which give direct checks
b1 &= pos.attacks_from<PAWN>(ksq, Them);
b2 &= pos.attacks_from<PAWN>(ksq, Them);
- // Pawn moves which gives discovered check. This is possible only if
- // the pawn is not on the same file as the enemy king, because we
- // don't generate captures.
+ // Add pawn moves which gives discovered check. This is possible only
+ // if the pawn is not on the same file as the enemy king, because we
+ // 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;
+ dc1 = move_pawns<UP>(pawns & target & ~file_bb(ksq)) & emptySquares;
+ dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;
}
}
- SERIALIZE_MOVES_D(b1, -TDELTA_N);
- SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
+ SERIALIZE_MOVES_D(b1, -UP);
+ SERIALIZE_MOVES_D(b2, -UP -UP);
}
// En passant captures
- if ((Type == CAPTURE || Type == EVASION) && pos.ep_square() != SQ_NONE)
+ if ((Type == MV_CAPTURE || Type == MV_EVASION) && pos.ep_square() != SQ_NONE)
{
assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
// An en passant capture can be an evasion only if the checking piece
// is the double pushed pawn and so is in the target. Otherwise this
// is a discovery check and we are forced to do otherwise.
- if (Type == EVASION && !bit_is_set(target, pos.ep_square() - TDELTA_N))
+ if (Type == MV_EVASION && !bit_is_set(target, pos.ep_square() - UP))
return mlist;
b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
return mlist;
}
- template<PieceType Piece>
- MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) {
+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
+
+ CastleRight f = CastleRight((Side == KING_SIDE ? WHITE_OO : WHITE_OOO) << us);
+ Color them = opposite_color(us);
+
+ // After castling, the rook and king's final positions are exactly the same
+ // in Chess960 as they would be in standard chess.
+ Square kfrom = pos.king_square(us);
+ Square rfrom = pos.castle_rook_square(f);
+ Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
+
+ assert(!pos.in_check());
+ assert(pos.piece_on(kfrom) == make_piece(us, KING));
+ assert(pos.piece_on(rfrom) == make_piece(us, ROOK));
+
+ // Unimpeded rule: All the squares between the king's initial and final squares
+ // (including the final square), and all the squares between the rook's initial
+ // and final squares (including the final square), must be vacant except for
+ // the king and castling rook.
+ for (Square s = Min(kfrom, kto); s <= Max(kfrom, kto); s++)
+ if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ ||(pos.attackers_to(s) & pos.pieces(them)))
+ return mlist;
- assert(Piece != QUEEN);
+ for (Square s = Min(rfrom, rto); s <= Max(rfrom, rto); s++)
+ if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ return mlist;
- Bitboard b = pos.attacks_from<Piece>(from) & pos.empty_squares();
- if (Piece == KING)
+ // Because we generate only legal castling moves we need to verify that
+ // when moving the castling rook we do not discover some hidden checker.
+ // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
+ if (pos.is_chess960())
{
- Square ksq = pos.king_square(opposite_color(pos.side_to_move()));
- b &= ~QueenPseudoAttacks[ksq];
+ Bitboard occ = pos.occupied_squares();
+ clear_bit(&occ, rfrom);
+ if (pos.attackers_to(kto, occ) & pos.pieces(them))
+ return mlist;
}
- SERIALIZE_MOVES(b);
- return mlist;
- }
-
- template<PieceType Piece>
- MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
- Bitboard dc, Square ksq) {
- assert(Piece != KING);
-
- Bitboard checkSqs, b;
- Square from;
- const Square* ptr = pos.piece_list_begin(us, Piece);
-
- if ((from = *ptr++) == SQ_NONE)
- return mlist;
-
- checkSqs = pos.attacks_from<Piece>(ksq) & pos.empty_squares();
- do
- {
- if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
- || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
- || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
- continue;
-
- if (dc && bit_is_set(dc, from))
- continue;
-
- b = pos.attacks_from<Piece>(from) & checkSqs;
- SERIALIZE_MOVES(b);
-
- } while ((from = *ptr++) != SQ_NONE);
+ (*mlist++).move = make_castle_move(kfrom, rfrom);
return mlist;
}
- template<CastlingSide Side>
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) {
-
- Color us = pos.side_to_move();
-
- if ( (Side == KING_SIDE && pos.can_castle_kingside(us))
- ||(Side == QUEEN_SIDE && pos.can_castle_queenside(us)))
- {
- Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
-
- assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING));
-
- Square rsq = (Side == KING_SIDE ? pos.initial_kr_square(us) : pos.initial_qr_square(us));
- Square s1 = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
- Square s2 = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
- Square s;
- bool illegal = false;
-
- assert(pos.piece_on(rsq) == piece_of_color_and_type(us, ROOK));
-
- // It is a bit complicated to correctly handle Chess960
- for (s = Min(ksq, s1); s <= Max(ksq, s1); s++)
- if ( (s != ksq && s != rsq && pos.square_is_occupied(s))
- ||(pos.attackers_to(s) & pos.pieces_of_color(them)))
- illegal = true;
-
- for (s = Min(rsq, s2); s <= Max(rsq, s2); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
-
- if ( Side == QUEEN_SIDE
- && square_file(rsq) == FILE_B
- && ( pos.piece_on(relative_square(us, SQ_A1)) == piece_of_color_and_type(them, ROOK)
- || pos.piece_on(relative_square(us, SQ_A1)) == piece_of_color_and_type(them, QUEEN)))
- illegal = true;
-
- if (!illegal)
- (*mlist++).move = make_castle_move(ksq, rsq);
- }
- return mlist;
- }
-}
+} // namespace
projects / stockfish / blobdiff