/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
// Templates for non-capture checks generation
template<PieceType Piece>
- MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from);
+ MoveStack* generate_discovered_checks(const Position&, MoveStack*, Square);
template<PieceType>
MoveStack* generate_direct_checks(const Position&, MoveStack*, Color, Bitboard, Square);
}
+/// generate_non_evasions() 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) {
+
+ assert(pos.is_ok());
+ assert(!pos.is_check());
+
+ Color us = pos.side_to_move();
+ Bitboard target = pos.pieces_of_color(opposite_color(us));
+
+ mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us, target);
+ mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us, pos.empty_squares());
+
+ target |= pos.empty_squares();
+
+ 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_capture_checks() generates all pseudo-legal non-captures and knight
/// underpromotions that give check. Returns a pointer to the end of the move list.
assert(pos.is_ok());
assert(!pos.is_check());
+ Bitboard b, dc;
+ Square from;
Color us = pos.side_to_move();
Square ksq = pos.king_square(opposite_color(us));
- Bitboard dc = pos.discovered_check_candidates(us);
assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING));
// Discovered non-capture checks
- Bitboard b = dc;
+ b = dc = pos.discovered_check_candidates(us);
+
while (b)
{
- Square from = pop_1st_bit(&b);
+ from = pop_1st_bit(&b);
switch (pos.type_of_piece_on(from))
{
case PAWN: /* Will be generated togheter with pawns direct checks */ break;
assert(pos.is_ok());
assert(pos.is_check());
- Bitboard b;
+ Bitboard b, target;
Square from, checksq;
int checkersCnt = 0;
Color us = pos.side_to_move();
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))
+ if (squares_straight_aligned(checksq, ksq))
sliderAttacks |= RookPseudoAttacks[checksq] | pos.attacks_from<BISHOP>(checksq);
else
sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from<ROOK>(checksq);
// Find squares where a blocking evasion or a capture of the
// checker piece is possible.
- Bitboard target = squares_between(checksq, ksq) | checkers;
+ target = squares_between(checksq, ksq) | checkers;
mlist = generate_piece_moves<PAWN, EVASION>(pos, mlist, us, target);
mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
assert(pos.is_ok());
- MoveStack* last;
+ MoveStack *last, *cur = mlist;
Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
// Generate pseudo-legal moves
- if (pos.is_check())
- last = generate_evasions(pos, mlist);
- else {
- last = generate_captures(pos, mlist);
- last = generate_noncaptures(pos, last);
- }
+ last = pos.is_check() ? generate_evasions(pos, mlist)
+ : generate_non_evasions(pos, mlist);
if (pseudoLegal)
return last;
// Remove illegal moves from the list
- for (MoveStack* cur = mlist; cur != last; cur++)
- if (!pos.pl_move_is_legal(cur->move, pinned))
- {
+ while (cur != last)
+ if (pos.pl_move_is_legal(cur->move, pinned))
+ cur++;
+ else
cur->move = (--last)->move;
- cur--;
- }
+
return last;
}
bool move_is_legal(const Position& pos, const Move m) {
- MoveStack mlist[256];
- MoveStack* last = generate_moves(pos, mlist, true);
- for (MoveStack* cur = mlist; cur != last; cur++)
+ MoveStack mlist[MOVES_MAX];
+ 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()));
assert(move_is_ok(m));
assert(pinned == pos.pinned_pieces(pos.side_to_move()));
- // Use a slower but simpler function for uncommon cases
- if (move_is_ep(m) || move_is_castle(m))
- return move_is_legal(pos, m);
-
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)
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)))
+ // 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);
}
template<PieceType Piece>
MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
- Square from;
Bitboard b;
+ 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, bool possiblePromotion) {
+ template<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 b;
Square to;
// Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black)
- Bitboard b1 = move_pawns<Us, Diagonal>(pawns) & ~TFileABB & enemyPieces;
+ b = move_pawns<Delta>(pawns) & target & ~TFileABB;
+ SERIALIZE_MOVES_D(b, -Delta);
+ return mlist;
+ }
- // Capturing promotions and under-promotions
- if (possiblePromotion)
- {
- Bitboard b2 = b1 & TRank8BB;
- b1 &= ~TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
+ template<Color Us, MoveType Type, SquareDelta Delta>
+ inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) {
- if (Type == CAPTURE || Type == EVASION)
- (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+ const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
- 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);
- }
+ Bitboard b;
+ Square to;
- // 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);
- }
- }
+ // Promotions and under-promotions, both captures and non-captures
+ b = move_pawns<Delta>(pawnsOn7) & target;
- // Serialize standard captures
- if (Type == CAPTURE || Type == EVASION)
- SERIALIZE_MOVES_D(b1, -TTDELTA_NE);
+ if (Delta != DELTA_N && Delta != DELTA_S)
+ b &= ~TFileABB;
+ while (b)
+ {
+ to = pop_1st_bit(&b);
+
+ if (Type == CAPTURE || Type == EVASION)
+ (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN);
+
+ if (Type == NON_CAPTURE || Type == 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);
+ }
+
+ // 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(opposite_color(Us))))
+ (*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 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;
+ Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares;
Bitboard pawns = pos.pieces(PAWN, Us);
- bool possiblePromotion = pawns & TRank7BB;
+ Bitboard pawnsOn7 = pawns & TRank7BB;
+ Bitboard enemyPieces = (Type == CAPTURE ? target : pos.pieces_of_color(Them));
- // Standard captures and capturing promotions and underpromotions
- if (Type == CAPTURE || Type == EVASION || possiblePromotion)
+ // Pre-calculate pawn pushes before changing emptySquares definition
+ if (Type != 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, possiblePromotion);
- mlist = generate_pawn_captures<Us, Type, DELTA_NW>(mlist, pawns, enemyPieces, possiblePromotion);
+ emptySquares = (Type == NON_CAPTURE ? target : pos.empty_squares());
+ pawnPushes = move_pawns<TDELTA_N>(pawns & ~TRank7BB) & emptySquares;
}
- // Non-capturing promotions and underpromotions
- if (possiblePromotion)
+ if (Type == 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);
+ emptySquares &= target; // Only blocking squares
+ enemyPieces &= target; // Capture only the checker piece
+ }
- if (Type == CAPTURE || Type == EVASION)
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ // Promotions and underpromotions
+ if (pawnsOn7)
+ {
+ if (Type == CAPTURE)
+ emptySquares = pos.empty_squares();
- 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);
- }
+ pawns &= ~TRank7BB;
+ mlist = generate_promotions<Us, Type, TDELTA_NE>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Us, Type, TDELTA_NW>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Us, Type, TDELTA_N >(pos, mlist, pawnsOn7, emptySquares);
+ }
- // 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);
- }
+ // Standard captures
+ if (Type == CAPTURE || Type == EVASION)
+ {
+ mlist = generate_pawn_captures<Type, TDELTA_NE>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures<Type, TDELTA_NW>(mlist, pawns, enemyPieces);
}
- // Standard pawn pushes and double pushes
+ // Single and double pawn pushes
if (Type != CAPTURE)
{
- 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 = pawnPushes & emptySquares;
+ b2 = move_pawns<TDELTA_N>(pawnPushes & TRank3BB) & emptySquares;
- // Filter out unwanted pushes according to the move type
- if (Type == EVASION)
+ if (Type == CHECK)
{
- b1 &= target;
- b2 &= target;
- }
- else if (Type == CHECK)
- {
- // Pawn moves which give direct cheks
+ // Condider 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<TDELTA_N>(pawns & target & ~file_bb(ksq)) & emptySquares;
+ dc2 = move_pawns<TDELTA_N>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;
Bitboard dc, Square ksq) {
assert(Piece != KING);
+ Bitboard checkSqs, b;
Square from;
- Bitboard checkSqs;
const Square* ptr = pos.piece_list_begin(us, Piece);
if ((from = *ptr++) == SQ_NONE)
if (dc && bit_is_set(dc, from))
continue;
-
Bitboard bb = pos.attacks_from<Piece>(from) & checkSqs;
- SERIALIZE_MOVES(bb);
+ b = pos.attacks_from<Piece>(from) & checkSqs;
+ SERIALIZE_MOVES(b);
} while ((from = *ptr++) != SQ_NONE);
Color us = pos.side_to_move();
- if ( (Side == KING_SIDE && pos.can_castle_kingside(us))
+ if ( (Side == KING_SIDE && pos.can_castle_kingside(us))
||(Side == QUEEN_SIDE && pos.can_castle_queenside(us)))
{
Color them = opposite_color(us);
projects / stockfish / blobdiff