/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008 Marco Costalba
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2009 Marco Costalba
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include <cassert>
+#include "bitcount.h"
#include "movegen.h"
// Simple macro to wrap a very common while loop, no facny, no flexibility,
// hardcoded list name 'mlist' and from square 'from'.
#define SERIALIZE_MOVES(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b))
+// 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
////
enum MoveType {
CAPTURE,
- NON_CAPTURE
+ NON_CAPTURE,
+ CHECK,
+ EVASION
};
// Functions
// Helper templates
template<CastlingSide Side>
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist);
-
- template<Color Us, Rank, Bitboard, SquareDelta>
- MoveStack* generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*);
-
- template<Color, Color, Bitboard, SquareDelta, SquareDelta, SquareDelta>
- MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist);
+ MoveStack* generate_castle_moves(const Position&, MoveStack*);
- template<Color, Color, Bitboard, Bitboard, SquareDelta, SquareDelta, SquareDelta>
- MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist);
+ template<Color Us, MoveType Type>
+ MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard = EmptyBoardBB,
+ Square = SQ_NONE, Bitboard = EmptyBoardBB);
- template<Color, Color, Bitboard, Bitboard, SquareDelta>
- MoveStack* generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*);
-
- // Template generate_piece_checks() with specializations
+ // Template generate_piece_moves (captures and non-captures) with specializations and overloads
template<PieceType>
- MoveStack* generate_piece_checks(const Position&, MoveStack*, Color, Bitboard, Square);
+ MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard);
template<>
- inline MoveStack* generate_piece_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
+ MoveStack* generate_piece_moves<KING>(const Position&, MoveStack*, Color, Bitboard);
- if (us == WHITE)
- return generate_pawn_checks<WHITE, BLACK, Rank8BB, Rank3BB, DELTA_N>(p, dc, ksq, m);
- else
- return generate_pawn_checks<BLACK, WHITE, Rank1BB, Rank6BB, DELTA_S>(p, dc, ksq, m);
+ template<PieceType Piece, MoveType Type>
+ inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) {
+ assert(Piece == PAWN);
+ assert(Type == CAPTURE || Type == NON_CAPTURE);
+
+ return (us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m)
+ : generate_pawn_moves<BLACK, Type>(p, m));
}
- // Template generate_piece_moves() with specializations and overloads
+ // Template generate_piece_checks with specializations
template<PieceType>
- MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard);
+ MoveStack* generate_piece_checks(const Position&, MoveStack*, Color, Bitboard, Square);
template<>
- MoveStack* generate_piece_moves<KING>(const Position&, MoveStack*, Color, Bitboard);
-
- template<PieceType Piece, MoveType Type>
- inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) {
-
- assert(Piece == PAWN);
+ inline MoveStack* generate_piece_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
- if (Type == CAPTURE)
- return (us == WHITE ? generate_pawn_captures<WHITE, BLACK, Rank8BB, DELTA_NE, DELTA_NW, DELTA_N>(p, m)
- : generate_pawn_captures<BLACK, WHITE, Rank1BB, DELTA_SE, DELTA_SW, DELTA_S>(p, m));
- else
- return (us == WHITE ? generate_pawn_noncaptures<WHITE, BLACK, Rank8BB, Rank3BB, DELTA_NE, DELTA_NW, DELTA_N>(p, m)
- : generate_pawn_noncaptures<BLACK, WHITE, Rank1BB, Rank6BB, DELTA_SE, DELTA_SW, DELTA_S>(p, m));
+ return (us == WHITE ? generate_pawn_moves<WHITE, CHECK>(p, m, dc, ksq)
+ : generate_pawn_moves<BLACK, CHECK>(p, m, dc, ksq));
}
+ // Template generate_piece_evasions with specializations
template<PieceType>
- MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard, Bitboard);
+ MoveStack* generate_piece_evasions(const Position&, MoveStack*, Color, Bitboard, Bitboard);
template<>
- inline MoveStack* generate_piece_moves<PAWN>(const Position& p, MoveStack* m,
- Color us, Bitboard t, Bitboard pnd) {
- if (us == WHITE)
- return generate_pawn_blocking_evasions<WHITE, RANK_8, Rank3BB, DELTA_N>(p, pnd, t, m);
- else
- return generate_pawn_blocking_evasions<BLACK, RANK_1, Rank6BB, DELTA_S>(p, pnd, t, m);
+ inline MoveStack* generate_piece_evasions<PAWN>(const Position& p, MoveStack* m,
+ Color us, Bitboard t, Bitboard pnd) {
+
+ return (us == WHITE ? generate_pawn_moves<WHITE, EVASION>(p, m, pnd, SQ_NONE, t)
+ : generate_pawn_moves<BLACK, EVASION>(p, m, pnd, SQ_NONE, t));
}
}
////
-/// generate_captures generates() all pseudo-legal captures and queen
-/// promotions. The return value is the number of moves generated.
+/// generate_captures() generates all pseudo-legal captures and queen
+/// promotions. Returns a pointer to the end of the move list.
-int generate_captures(const Position& pos, MoveStack* mlist) {
+MoveStack* generate_captures(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));
- MoveStack* mlist_start = mlist;
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);
- mlist = generate_piece_moves<KING>(pos, mlist, us, target);
- return int(mlist - mlist_start);
+ return generate_piece_moves<KING>(pos, mlist, us, target);
}
/// generate_noncaptures() generates all pseudo-legal non-captures and
-/// underpromotions. The return value is the number of moves generated.
+/// underpromotions. Returns a pointer to the end of the move list.
-int generate_noncaptures(const Position& pos, MoveStack* mlist) {
+MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
assert(!pos.is_check());
Color us = pos.side_to_move();
Bitboard target = pos.empty_squares();
- MoveStack* mlist_start = mlist;
mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us);
mlist = generate_piece_moves<KNIGHT>(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);
- mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
- return int(mlist - mlist_start);
+ return generate_castle_moves<QUEEN_SIDE>(pos, mlist);
}
-/// generate_checks() generates all pseudo-legal non-capturing, non-promoting
-/// checks. It returns the number of generated moves.
+/// generate_non_capture_checks() generates all pseudo-legal non-captures and
+/// underpromotions that give check. Returns a pointer to the end of the move list.
-int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
+MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
assert(pos.is_ok());
assert(!pos.is_check());
Color us = pos.side_to_move();
Square ksq = pos.king_square(opposite_color(us));
- MoveStack* mlist_start = mlist;
- assert(pos.piece_on(ksq) == king_of_color(opposite_color(us)));
+ assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING));
// Pieces moves
mlist = generate_piece_checks<PAWN>(pos, mlist, us, dc, ksq);
&& castling_is_check(pos, KING_SIDE))
mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
- return int(mlist - mlist_start);
+ return mlist;
}
/// generate_evasions() generates all check evasions when the side to move is
/// in check. Unlike the other move generation functions, this one generates
-/// only legal moves. It returns the number of generated moves.
+/// only legal moves. Returns a pointer to the end of the move list.
-int generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) {
+MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) {
assert(pos.is_ok());
assert(pos.is_check());
Color us = pos.side_to_move();
Color them = opposite_color(us);
Square ksq = pos.king_square(us);
- MoveStack* mlist_start = mlist;
+ Bitboard sliderAttacks = EmptyBoardBB;
+ Bitboard checkers = pos.checkers();
- assert(pos.piece_on(ksq) == king_of_color(us));
+ assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING));
// The bitboard of occupied pieces without our king
Bitboard b_noKing = pos.occupied_squares();
clear_bit(&b_noKing, ksq);
- // Find squares attacked by slider checkers, we will
- // remove them from king evasions set so to avoid a couple
+ // Find squares attacked by slider checkers, we will remove
+ // them from the king evasions set so to avoid a couple
// of cycles in the slow king evasions legality check loop
- // and to be able to use square_is_attacked().
- Bitboard checkers = pos.checkers();
- Bitboard checkersAttacks = EmptyBoardBB;
- Bitboard b = checkers & (pos.queens() | pos.bishops());
+ // and to be able to use attackers_to().
+ Bitboard b = checkers & pos.pieces(BISHOP, QUEEN);
while (b)
{
from = pop_1st_bit(&b);
- checkersAttacks |= bishop_attacks_bb(from, b_noKing);
+ sliderAttacks |= bishop_attacks_bb(from, b_noKing);
}
- b = checkers & (pos.queens() | pos.rooks());
+ b = checkers & pos.pieces(ROOK, QUEEN);
while (b)
{
from = pop_1st_bit(&b);
- checkersAttacks |= rook_attacks_bb(from, b_noKing);
+ sliderAttacks |= rook_attacks_bb(from, b_noKing);
}
- // Generate evasions for king
- Bitboard b1 = pos.piece_attacks<KING>(ksq) & ~pos.pieces_of_color(us) & ~checkersAttacks;
+ // Generate evasions for king, capture and non capture moves
+ Bitboard enemy = pos.pieces_of_color(them);
+ Bitboard b1 = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
while (b1)
{
+ // Note that we can use attackers_to() only because we have already
+ // removed from b1 the squares attacked by slider checkers.
to = pop_1st_bit(&b1);
- // Note that we can use square_is_attacked() only because we
- // have already removed slider checkers.
- if (!pos.square_is_attacked(to, them))
+ if (!(pos.attackers_to(to) & enemy))
(*mlist++).move = make_move(ksq, to);
}
// Generate captures of the checking piece
// Pawn captures
- b1 = pos.pawn_attacks(them, checksq) & pos.pawns(us) & ~pinned;
+ b1 = pos.attacks_from<PAWN>(checksq, them) & pos.pieces(PAWN, us) & ~pinned;
while (b1)
{
from = pop_1st_bit(&b1);
}
// Pieces captures
- b1 = ( (pos.piece_attacks<KNIGHT>(checksq) & pos.knights(us))
- | (pos.piece_attacks<BISHOP>(checksq) & pos.bishops_and_queens(us))
- | (pos.piece_attacks<ROOK>(checksq) & pos.rooks_and_queens(us)) ) & ~pinned;
+ b1 = ( (pos.attacks_from<KNIGHT>(checksq) & pos.pieces(KNIGHT, us))
+ | (pos.attacks_from<BISHOP>(checksq) & pos.pieces(BISHOP, QUEEN, us))
+ | (pos.attacks_from<ROOK>(checksq) & pos.pieces(ROOK, QUEEN, us)) ) & ~pinned;
while (b1)
{
(*mlist++).move = make_move(from, checksq);
}
- // Blocking check evasions are possible only if the checking piece is
- // a slider.
- if (checkers & pos.sliders())
+ // Blocking check evasions are possible only if the checking piece is a slider
+ if (sliderAttacks)
{
Bitboard blockSquares = squares_between(checksq, ksq);
assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB);
- if (blockSquares != EmptyBoardBB)
+ if (blockSquares)
{
- mlist = generate_piece_moves<PAWN>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<BISHOP>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<ROOK>(pos, mlist, us, blockSquares, pinned);
- mlist = generate_piece_moves<QUEEN>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<PAWN>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<KNIGHT>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<BISHOP>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<ROOK>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_evasions<QUEEN>(pos, mlist, us, blockSquares, pinned);
}
}
// check. If pos.ep_square() is set, the last move made must have been
// a double pawn push. If, furthermore, the checking piece is a pawn,
// an en passant check evasion may be possible.
- if (pos.ep_square() != SQ_NONE && (checkers & pos.pawns(them)))
+ if (pos.ep_square() != SQ_NONE && (checkers & pos.pieces(PAWN, them)))
{
to = pos.ep_square();
- b1 = pos.pawn_attacks(them, to) & pos.pawns(us);
+ b1 = pos.attacks_from<PAWN>(to, them) & pos.pieces(PAWN, us);
// The checking pawn cannot be a discovered (bishop) check candidate
// otherwise we were in check also before last double push move.
}
}
}
- return int(mlist - mlist_start);
+ return mlist;
}
-/// generate_legal_moves() computes a complete list of legal moves in the
-/// current position. This function is not very fast, and should be used
-/// only in situations where performance is unimportant. It wouldn't be
-/// very hard to write an efficient legal move generator, but for the moment
-/// we don't need it.
+/// 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.
-int generate_legal_moves(const Position& pos, MoveStack* mlist) {
+MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal) {
assert(pos.is_ok());
return generate_evasions(pos, mlist, pinned);
// Generate pseudo-legal moves
- int n = generate_captures(pos, mlist);
- n += generate_noncaptures(pos, mlist + n);
+ MoveStack* last = generate_captures(pos, mlist);
+ last = generate_noncaptures(pos, last);
+ if (pseudoLegal)
+ return last;
// Remove illegal moves from the list
- for (int i = 0; i < n; i++)
- if (!pos.pl_move_is_legal(mlist[i].move, pinned))
- mlist[i--].move = mlist[--n].move;
-
- return n;
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ if (!pos.pl_move_is_legal(cur->move, pinned))
+ {
+ cur->move = (--last)->move;
+ cur--;
+ }
+ return last;
}
/// move_is_legal() takes a position and a (not necessarily pseudo-legal)
-/// move and a pinned pieces bitboard as input, and tests whether
-/// the move is legal. If the move is legal, the move itself is
-/// returned. If not, the function returns false. This function must
-/// only be used when the side to move is not in check.
+/// 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* last = generate_moves(pos, mlist, true);
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ if (cur->move == m)
+ return pos.pl_move_is_legal(m);
+
+ 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.
+/// This version must only be used when the side to move is not in check.
bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
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);
// If the from square is not occupied by a piece belonging to the side to
if (color_of_piece(pc) != us)
return false;
- Square to = move_to(m);
-
- // En passant moves
- if (move_is_ep(m))
- {
- // The piece must be a pawn and destination square must be the
- // en passant square.
- if ( type_of_piece(pc) != PAWN
- || to != pos.ep_square())
- return false;
-
- assert(pos.square_is_empty(to));
- assert(pos.piece_on(to - pawn_push(us)) == pawn_of_color(them));
-
- // The move is pseudo-legal, check if it is also legal
- return pos.pl_move_is_legal(m, pinned);
- }
-
- // Castling moves
- if (move_is_short_castle(m))
- {
- // The piece must be a king and side to move must still have
- // the right to castle kingside.
- if ( type_of_piece(pc) != KING
- ||!pos.can_castle_kingside(us))
- return false;
-
- assert(from == pos.king_square(us));
- assert(to == pos.initial_kr_square(us));
- assert(pos.piece_on(to) == rook_of_color(us));
-
- Square g1 = relative_square(us, SQ_G1);
- Square f1 = relative_square(us, SQ_F1);
- Square s;
- bool illegal = false;
-
- // Check if any of the squares between king and rook
- // is occupied or under attack.
- for (s = Min(from, g1); s <= Max(from, g1); s++)
- if ( (s != from && s != to && !pos.square_is_empty(s))
- || pos.square_is_attacked(s, them))
- illegal = true;
-
- // Check if any of the squares between king and rook
- // is occupied.
- for (s = Min(to, f1); s <= Max(to, f1); s++)
- if (s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
-
- return !illegal;
- }
-
- if (move_is_long_castle(m))
- {
- // The piece must be a king and side to move must still have
- // the right to castle kingside.
- if ( type_of_piece(pc) != KING
- ||!pos.can_castle_queenside(us))
- return false;
-
- assert(from == pos.king_square(us));
- assert(to == pos.initial_qr_square(us));
- assert(pos.piece_on(to) == rook_of_color(us));
-
- Square c1 = relative_square(us, SQ_C1);
- Square d1 = relative_square(us, SQ_D1);
- Square s;
- bool illegal = false;
-
- for (s = Min(from, c1); s <= Max(from, c1); s++)
- if( (s != from && s != to && !pos.square_is_empty(s))
- || pos.square_is_attacked(s, them))
- illegal = true;
-
- for (s = Min(to, d1); s <= Max(to, d1); s++)
- if(s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
-
- if ( square_file(to) == FILE_B
- && ( pos.piece_on(to + DELTA_W) == rook_of_color(them)
- || pos.piece_on(to + DELTA_W) == queen_of_color(them)))
- illegal = true;
-
- return !illegal;
- }
-
- // Normal moves
-
// The destination square cannot be occupied by a friendly piece
if (pos.color_of_piece_on(to) == us)
return false;
- // Proceed according to the type of the moving piece.
+ // Handle the special case of a pawn move
if (type_of_piece(pc) == PAWN)
{
- // If the destination square is on the 8/1th rank, the move must
- // be a promotion.
- if ( ( (square_rank(to) == RANK_8 && us == WHITE)
- ||(square_rank(to) == RANK_1 && us != WHITE))
- && !move_promotion(m))
+ // Move direction must be compatible with pawn color
+ int direction = to - from;
+ if ((us == WHITE) != (direction > 0))
return false;
- // Proceed according to the square delta between the source and
- // destionation squares.
- switch (to - from)
+ // 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;
+
+ // Proceed according to the square delta between the origin and
+ // destination squares.
+ switch (direction)
{
case DELTA_NW:
case DELTA_NE:
}
// Luckly we can handle all the other pieces in one go
- return ( pos.piece_attacks_square(from, to)
+ return ( bit_is_set(pos.attacks_from(pc, from), to)
&& pos.pl_move_is_legal(m, pinned)
- && !move_promotion(m));
+ && !move_is_promotion(m));
}
Square from;
Bitboard b;
+ const Square* ptr = pos.piece_list_begin(us, Piece);
- for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
+ while ((from = *ptr++) != SQ_NONE)
{
- from = pos.piece_list(us, Piece, i);
- b = pos.piece_attacks<Piece>(from) & target;
+ b = pos.attacks_from<Piece>(from) & target;
SERIALIZE_MOVES(b);
}
return mlist;
}
+ template<>
+ 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;
+ }
+
template<PieceType Piece>
- MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist,
- Color us, Bitboard target, Bitboard pinned) {
+ MoveStack* generate_piece_evasions(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target, Bitboard pinned) {
Square from;
Bitboard b;
+ const Square* ptr = pos.piece_list_begin(us, Piece);
- for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
+ while ((from = *ptr++) != SQ_NONE)
{
- from = pos.piece_list(us, Piece, i);
if (pinned && bit_is_set(pinned, from))
continue;
- b = pos.piece_attacks<Piece>(from) & target;
+ b = pos.attacks_from<Piece>(from) & target;
SERIALIZE_MOVES(b);
}
return mlist;
}
- template<>
- MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
-
- Bitboard b;
- Square from = pos.king_square(us);
+ template<Color Us, SquareDelta Direction>
+ inline Bitboard move_pawns(Bitboard p) {
- b = pos.piece_attacks<KING>(from) & target;
- SERIALIZE_MOVES(b);
- return mlist;
+ 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, Color Them, Bitboard TRank8BB, SquareDelta TDELTA_NE,
- SquareDelta TDELTA_NW, SquareDelta TDELTA_N
- >
- MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist) {
+ template<Color Us, SquareDelta Diagonal>
+ MoveStack* generate_pawn_diagonal_captures(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion) {
+
+ // 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);
Square to;
- Bitboard pawns = pos.pawns(Us);
- Bitboard enemyPieces = pos.pieces_of_color(Them);
- // Captures in the a1-h8 (a8-h1 for black) direction
- Bitboard b1 = (Us == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces;
+ // 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;
// Capturing promotions
- Bitboard b2 = b1 & TRank8BB;
- while (b2)
+ if (promotion)
{
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, QUEEN);
+ Bitboard b2 = b1 & TRank8BB;
+ b1 &= ~TRank8BB;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+ }
}
// Capturing non-promotions
- b2 = b1 & ~TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TDELTA_NE, to);
- }
+ SERIALIZE_MOVES_D(b1, -TTDELTA_NE);
+ return mlist;
+ }
- // Captures in the h1-a8 (h8-a1 for black) direction
- b1 = (Us == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces;
+ template<Color Us, MoveType Type>
+ MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard dcp,
+ Square ksq, Bitboard blockSquares) {
- // Capturing promotions
- b2 = b1 & TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, QUEEN);
- }
+ // 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_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
+ const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
+ const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
- // Capturing non-promotions
- b2 = b1 & ~TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TDELTA_NW, to);
- }
+ Bitboard b1, b2, dcPawns1, dcPawns2;
+ Square to;
+ Bitboard pawns = (Type == EVASION ? pos.pieces(PAWN, Us) & ~dcp : pos.pieces(PAWN, Us));
+ bool possiblePromotion = pawns & TRank7BB;
- // Non-capturing promotions
- b1 = (Us == WHITE ? pawns << 8 : pawns >> 8) & pos.empty_squares() & TRank8BB;
- while (b1)
+ if (Type == CAPTURE)
{
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ // Standard captures and capturing promotions in both directions
+ Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
+ mlist = generate_pawn_diagonal_captures<Us, DELTA_NE>(mlist, pawns, enemyPieces, possiblePromotion);
+ mlist = generate_pawn_diagonal_captures<Us, DELTA_NW>(mlist, pawns, enemyPieces, possiblePromotion);
}
- // En passant captures
- if (pos.ep_square() != SQ_NONE)
+ if (possiblePromotion)
{
- assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
- assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
+ // When generating checks consider under-promotion moves (both captures
+ // and non captures) only if can give a discovery check. Note that dcp
+ // is dc bitboard or pinned bitboard when Type == EVASION.
+ Bitboard pp = (Type == CHECK ? pawns & dcp : pawns);
- b1 = pawns & pos.pawn_attacks(Them, pos.ep_square());
- assert(b1 != EmptyBoardBB);
+ if (Type != EVASION && Type != CAPTURE)
+ {
+ Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
+
+ // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
+ b1 = move_pawns<Us, DELTA_NE>(pp) & ~FileABB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
+ }
+
+ // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
+ b1 = move_pawns<Us, DELTA_NW>(pp) & ~FileHBB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
+ }
+ }
+
+ // Underpromotion pawn pushes. Also queen promotions for evasions and captures.
+ b1 = move_pawns<Us, DELTA_N>(pp) & TRank8BB;
+ b1 &= (Type == EVASION ? blockSquares : pos.empty_squares());
while (b1)
{
to = pop_1st_bit(&b1);
- (*mlist++).move = make_ep_move(to, pos.ep_square());
+ if (Type == EVASION || Type == CAPTURE)
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+
+ if (Type != CAPTURE)
+ {
+ (*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);
+ }
}
}
- return mlist;
- }
-
- template<Color Us, Color Them, Bitboard TRank8BB, Bitboard TRank3BB,
- SquareDelta TDELTA_NE, SquareDelta TDELTA_NW, SquareDelta TDELTA_N
- >
- MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) {
-
- Bitboard pawns = pos.pawns(Us);
- Bitboard enemyPieces = pos.pieces_of_color(Them);
- Bitboard emptySquares = pos.empty_squares();
- Bitboard b1, b2;
- Square to;
-
- // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
- b1 = (Us == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces & TRank8BB;
- while (b1)
- {
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
- }
- // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
- b1 = (Us == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces & TRank8BB;
- while (b1)
+ if (Type != CAPTURE)
{
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
- }
+ Bitboard emptySquares = pos.empty_squares();
+ dcPawns1 = dcPawns2 = EmptyBoardBB;
+ if (Type == CHECK && (pawns & dcp))
+ {
+ // 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.
+ dcPawns1 = move_pawns<Us, DELTA_N>(pawns & dcp & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
+ dcPawns2 = move_pawns<Us, DELTA_N>(dcPawns1 & TRank3BB) & emptySquares;
+ }
- // Single pawn pushes
- b1 = (Us == WHITE ? pawns << 8 : pawns >> 8) & emptySquares;
- b2 = b1 & TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*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);
- }
- b2 = b1 & ~TRank8BB;
- while (b2)
- {
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TDELTA_N, to);
+ // Single pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
+ b2 = (Type == CHECK ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns1 :
+ (Type == EVASION ? b1 & blockSquares : b1));
+ SERIALIZE_MOVES_D(b2, -TDELTA_N);
+
+ // Double pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
+ b2 = (Type == CHECK ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns2 :
+ (Type == EVASION ? b1 & blockSquares : b1));
+ SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
}
-
- // Double pawn pushes
- b2 = (Us == WHITE ? (b1 & TRank3BB) << 8 : (b1 & TRank3BB) >> 8) & emptySquares;
- while (b2)
+ else if (pos.ep_square() != SQ_NONE) // En passant captures
{
- to = pop_1st_bit(&b2);
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
- }
- return mlist;
- }
-
-
- template<Color Us, Color Them, Bitboard TRank8BB, Bitboard TRank3BB, SquareDelta TDELTA_N>
- MoveStack* generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist)
- {
- // Find all friendly pawns not on the enemy king's file
- Bitboard b1, b2, b3;
- Bitboard empty = pos.empty_squares();
+ assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
+ assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
- if (dc != EmptyBoardBB)
- {
- // 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.
- b1 = pos.pawns(Us) & ~file_bb(ksq);
-
- // Discovered checks, single pawn pushes, no promotions
- b2 = b3 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & empty & ~TRank8BB;
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N, to);
- }
+ b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
+ assert(b1 != EmptyBoardBB);
- // Discovered checks, double pawn pushes
- b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8) & empty;
- while (b3)
+ while (b1)
{
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_ep_move(to, pos.ep_square());
}
}
-
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king.
- b1 = pos.pawns(Us) & neighboring_files_bb(ksq) & ~dc;
-
- // Direct checks, single pawn pushes
- b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & empty;
- b3 = b2 & pos.pawn_attacks(Them, ksq);
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N, to);
- }
-
- // Direct checks, double pawn pushes
- b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8)
- & empty
- & pos.pawn_attacks(Them, ksq);
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
- }
return mlist;
}
MoveStack* generate_piece_checks(const Position& pos, MoveStack* mlist, Color us,
Bitboard dc, Square ksq) {
- Bitboard target = pos.pieces_of_color_and_type(us, Piece);
+ Bitboard target = pos.pieces(Piece, us);
- // Discovered checks
+ // Discovered non-capture checks
Bitboard b = target & dc;
+
+ assert(Piece != QUEEN || !b);
+
while (b)
{
Square from = pop_1st_bit(&b);
- Bitboard bb = pos.piece_attacks<Piece>(from) & pos.empty_squares();
+ Bitboard bb = pos.attacks_from<Piece>(from) & pos.empty_squares();
if (Piece == KING)
bb &= ~QueenPseudoAttacks[ksq];
SERIALIZE_MOVES(bb);
}
- // Direct checks
+ // Direct non-capture checks
b = target & ~dc;
- if (Piece == KING || !b)
- return mlist;
-
- Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
- while (b)
- {
- Square from = pop_1st_bit(&b);
- Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
- SERIALIZE_MOVES(bb);
- }
- return mlist;
- }
-
- template<Color Us, Rank TRANK_8, Bitboard TRank3BB, SquareDelta TDELTA_N>
- MoveStack* generate_pawn_blocking_evasions(const Position& pos, Bitboard pinned,
- Bitboard blockSquares, MoveStack* mlist) {
- Square to;
-
- // Find non-pinned pawns
- Bitboard b1 = pos.pawns(Us) & ~pinned;
-
- // Single pawn pushes. We don't have to AND with empty squares here,
- // because the blocking squares will always be empty.
- Bitboard b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & blockSquares;
- while (b2)
+ Bitboard checkSqs = pos.attacks_from<Piece>(ksq) & pos.empty_squares();
+ if (Piece != KING && checkSqs)
{
- to = pop_1st_bit(&b2);
-
- assert(pos.piece_on(to) == EMPTY);
-
- if (square_rank(to) == TRANK_8)
+ while (b)
{
- (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
- (*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);
- } else
- (*mlist++).move = make_move(to - TDELTA_N, to);
- }
-
- // Double pawn pushes
- b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & pos.empty_squares() & TRank3BB;
- b2 = (Us == WHITE ? b2 << 8 : b2 >> 8) & blockSquares;
- while (b2)
- {
- to = pop_1st_bit(&b2);
-
- assert(pos.piece_on(to) == EMPTY);
- assert(Us != WHITE || square_rank(to) == RANK_4);
- assert(Us != BLACK || square_rank(to) == RANK_5);
-
- (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ Square from = pop_1st_bit(&b);
+ if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
+ || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
+ || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
+ continue;
+
+ Bitboard bb = pos.attacks_from<Piece>(from) & checkSqs;
+ SERIALIZE_MOVES(bb);
+ }
}
return mlist;
}
Color them = opposite_color(us);
Square ksq = pos.king_square(us);
- assert(pos.piece_on(ksq) == king_of_color(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 s;
bool illegal = false;
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ 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.square_is_attacked(s, them))
+ ||(pos.attackers_to(s) & pos.pieces_of_color(them)))
illegal = true;
for (s = Min(rsq, s2); s <= Max(rsq, s2); s++)
if ( Side == QUEEN_SIDE
&& square_file(rsq) == FILE_B
- && ( pos.piece_on(relative_square(us, SQ_A1)) == rook_of_color(them)
- || pos.piece_on(relative_square(us, SQ_A1)) == queen_of_color(them)))
+ && ( 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)