Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, 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
namespace {
- template<CastlingRight Cr, bool Checks, bool Chess960>
- ExtMove* generate_castling(const Position& pos, ExtMove* moveList, Color us) {
-
- static constexpr bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO);
-
- if (pos.castling_impeded(Cr) || !pos.can_castle(Cr))
- return moveList;
-
- // After castling, the rook and king final positions are the same in Chess960
- // as they would be in standard chess.
- Square kfrom = pos.square<KING>(us);
- Square rfrom = pos.castling_rook_square(Cr);
- Square kto = relative_square(us, KingSide ? SQ_G1 : SQ_C1);
- Bitboard enemies = pos.pieces(~us);
-
- assert(!pos.checkers());
-
- const Direction step = Chess960 ? kto > kfrom ? WEST : EAST
- : KingSide ? WEST : EAST;
-
- for (Square s = kto; s != kfrom; s += step)
- if (pos.attackers_to(s) & enemies)
- return moveList;
-
- // 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 (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
- return moveList;
-
- Move m = make<CASTLING>(kfrom, rfrom);
-
- if (Checks && !pos.gives_check(m))
- return moveList;
-
- *moveList++ = m;
- return moveList;
- }
-
-
template<GenType Type, Direction D>
ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) {
template<Color Us, GenType Type>
ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
- // Compute our parametrized parameters at compile time, named according to
- // the point of view of white side.
+ // Compute some compile time parameters relative to the white side
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
- constexpr Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
constexpr Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ constexpr Direction Up = pawn_push(Us);
constexpr Direction UpRight = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
constexpr Direction UpLeft = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
+ const Square ksq = pos.square<KING>(Them);
Bitboard emptySquares;
Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB;
if (Type == QUIET_CHECKS)
{
- Square ksq = pos.square<KING>(Them);
-
b1 &= pos.attacks_from<PAWN>(ksq, Them);
b2 &= pos.attacks_from<PAWN>(ksq, Them);
// if the pawn is not on the same file as the enemy king, because we
// don't generate captures. Note that a possible discovery check
// promotion has been already generated amongst the captures.
- Bitboard dcCandidates = pos.blockers_for_king(Them);
- if (pawnsNotOn7 & dcCandidates)
+ Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7;
+ if (dcCandidateQuiets)
{
- Bitboard dc1 = shift<Up>(pawnsNotOn7 & dcCandidates) & emptySquares & ~file_bb(ksq);
+ Bitboard dc1 = shift<Up>(dcCandidateQuiets) & emptySquares & ~file_bb(ksq);
Bitboard dc2 = shift<Up>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
}
// Promotions and underpromotions
- if (pawnsOn7 && (Type != EVASIONS || (target & TRank8BB)))
+ if (pawnsOn7)
{
if (Type == CAPTURES)
emptySquares = ~pos.pieces();
Bitboard b2 = shift<UpLeft >(pawnsOn7) & enemies;
Bitboard b3 = shift<Up >(pawnsOn7) & emptySquares;
- Square ksq = pos.square<KING>(Them);
-
while (b1)
moveList = make_promotions<Type, UpRight>(moveList, pop_lsb(&b1), ksq);
ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
Bitboard target) {
- assert(Pt != KING && Pt != PAWN);
+ static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()");
const Square* pl = pos.squares<Pt>(us);
template<Color Us, GenType Type>
ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) {
- constexpr bool Checks = Type == QUIET_CHECKS;
+ constexpr CastlingRights OO = Us & KING_SIDE;
+ constexpr CastlingRights OOO = Us & QUEEN_SIDE;
+ constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantations
moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
moveList = generate_moves<KNIGHT, Checks>(pos, moveList, Us, target);
Bitboard b = pos.attacks_from<KING>(ksq) & target;
while (b)
*moveList++ = make_move(ksq, pop_lsb(&b));
- }
- if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us))
- {
- if (pos.is_chess960())
- {
- moveList = generate_castling<MakeCastling<Us, KING_SIDE>::right, Checks, true>(pos, moveList, Us);
- moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, true>(pos, moveList, Us);
- }
- else
+ if (Type != CAPTURES && pos.can_castle(CastlingRights(OO | OOO)))
{
- moveList = generate_castling<MakeCastling<Us, KING_SIDE>::right, Checks, false>(pos, moveList, Us);
- moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, false>(pos, moveList, Us);
+ if (!pos.castling_impeded(OO) && pos.can_castle(OO))
+ *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OO));
+
+ if (!pos.castling_impeded(OOO) && pos.can_castle(OOO))
+ *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(OOO));
}
}
} // namespace
-/// generate<CAPTURES> generates all pseudo-legal captures and queen
-/// promotions. Returns a pointer to the end of the move list.
-///
-/// generate<QUIETS> generates all pseudo-legal non-captures and
-/// underpromotions. Returns a pointer to the end of the move list.
+/// <CAPTURES> Generates all pseudo-legal captures and queen promotions
+/// <QUIETS> Generates all pseudo-legal non-captures and underpromotions
+/// <NON_EVASIONS> Generates all pseudo-legal captures and non-captures
///
-/// generate<NON_EVASIONS> generates all pseudo-legal captures and
-/// non-captures. Returns a pointer to the end of the move list.
+/// Returns a pointer to the end of the move list.
template<GenType Type>
ExtMove* generate(const Position& pos, ExtMove* moveList) {
- assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
+ static_assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS, "Unsupported type in generate()");
assert(!pos.checkers());
Color us = pos.side_to_move();
projects / stockfish / blobdiff