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) 2015-2016 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 const 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 Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E
- : KingSide ? DELTA_W : DELTA_E;
-
- for (Square s = kto; s != kfrom; s += K)
- 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, Square Delta>
+ template<GenType Type, Direction D>
ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) {
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
- *moveList++ = make<PROMOTION>(to - Delta, to, QUEEN);
+ *moveList++ = make<PROMOTION>(to - D, to, QUEEN);
if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
- *moveList++ = make<PROMOTION>(to - Delta, to, ROOK);
- *moveList++ = make<PROMOTION>(to - Delta, to, BISHOP);
- *moveList++ = make<PROMOTION>(to - Delta, to, KNIGHT);
+ *moveList++ = make<PROMOTION>(to - D, to, ROOK);
+ *moveList++ = make<PROMOTION>(to - D, to, BISHOP);
+ *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
}
// Knight promotion is the only promotion that can give a direct check
// that's not already included in the queen promotion.
- if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ksq))
- *moveList++ = make<PROMOTION>(to - Delta, to, KNIGHT);
+ if (Type == QUIET_CHECKS && (PseudoAttacks[KNIGHT][to] & ksq))
+ *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
+ else
+ (void)ksq; // Silence a warning under MSVC
return moveList;
}
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.
- 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 Square Up = (Us == WHITE ? DELTA_N : DELTA_S);
- const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
- const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
+ // Compute some compile time parameters relative to the white side
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+ constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ constexpr Direction UpRight = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
+ constexpr Direction UpLeft = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
Bitboard emptySquares;
{
emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
- Bitboard b1 = shift_bb<Up>(pawnsNotOn7) & emptySquares;
- Bitboard b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;
+ Bitboard b1 = shift<Up>(pawnsNotOn7) & emptySquares;
+ Bitboard b2 = shift<Up>(b1 & TRank3BB) & emptySquares;
if (Type == EVASIONS) // Consider only blocking squares
{
// 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.discovered_check_candidates();
- if (pawnsNotOn7 & dcCandidates)
+ Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7;
+ if (dcCandidateQuiets)
{
- Bitboard dc1 = shift_bb<Up>(pawnsNotOn7 & dcCandidates) & emptySquares & ~file_bb(ksq);
- Bitboard dc2 = shift_bb<Up>(dc1 & TRank3BB) & emptySquares;
+ Bitboard dc1 = shift<Up>(dcCandidateQuiets) & emptySquares & ~file_bb(ksq);
+ Bitboard dc2 = shift<Up>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
b2 |= dc2;
}
// Promotions and underpromotions
- if (pawnsOn7 && (Type != EVASIONS || (target & TRank8BB)))
+ if (pawnsOn7)
{
if (Type == CAPTURES)
emptySquares = ~pos.pieces();
if (Type == EVASIONS)
emptySquares &= target;
- Bitboard b1 = shift_bb<Right>(pawnsOn7) & enemies;
- Bitboard b2 = shift_bb<Left >(pawnsOn7) & enemies;
- Bitboard b3 = shift_bb<Up >(pawnsOn7) & emptySquares;
+ Bitboard b1 = shift<UpRight>(pawnsOn7) & enemies;
+ Bitboard b2 = shift<UpLeft >(pawnsOn7) & enemies;
+ Bitboard b3 = shift<Up >(pawnsOn7) & emptySquares;
Square ksq = pos.square<KING>(Them);
while (b1)
- moveList = make_promotions<Type, Right>(moveList, pop_lsb(&b1), ksq);
+ moveList = make_promotions<Type, UpRight>(moveList, pop_lsb(&b1), ksq);
while (b2)
- moveList = make_promotions<Type, Left >(moveList, pop_lsb(&b2), ksq);
+ moveList = make_promotions<Type, UpLeft >(moveList, pop_lsb(&b2), ksq);
while (b3)
- moveList = make_promotions<Type, Up >(moveList, pop_lsb(&b3), ksq);
+ moveList = make_promotions<Type, Up >(moveList, pop_lsb(&b3), ksq);
}
// Standard and en-passant captures
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
{
- Bitboard b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
- Bitboard b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
+ Bitboard b1 = shift<UpRight>(pawnsNotOn7) & enemies;
+ Bitboard b2 = shift<UpLeft >(pawnsNotOn7) & enemies;
while (b1)
{
Square to = pop_lsb(&b1);
- *moveList++ = make_move(to - Right, to);
+ *moveList++ = make_move(to - UpRight, to);
}
while (b2)
{
Square to = pop_lsb(&b2);
- *moveList++ = make_move(to - Left, to);
+ *moveList++ = make_move(to - UpLeft, to);
}
if (pos.ep_square() != SQ_NONE)
if (Checks)
{
if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
- && !(PseudoAttacks[Pt][from] & target & pos.check_info().checkSquares[Pt]))
+ && !(PseudoAttacks[Pt][from] & target & pos.check_squares(Pt)))
continue;
- if (pos.discovered_check_candidates() & from)
+ if (pos.blockers_for_king(~us) & from)
continue;
}
Bitboard b = pos.attacks_from<Pt>(from) & target;
if (Checks)
- b &= pos.check_info().checkSquares[Pt];
+ b &= pos.check_squares(Pt);
while (b)
*moveList++ = make_move(from, pop_lsb(&b));
template<Color Us, GenType Type>
ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) {
- const 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())
+ if (Type != CAPTURES && pos.can_castle(CastlingRights(OO | OOO)))
{
- 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
- {
- 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(!pos.checkers());
Color us = pos.side_to_move();
- Bitboard dc = pos.discovered_check_candidates();
+ Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us);
while (dc)
{
if (pt == PAWN)
continue; // Will be generated together with direct checks
- Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
+ Bitboard b = pos.attacks_from(pt, from) & ~pos.pieces();
if (pt == KING)
b &= ~PseudoAttacks[QUEEN][pos.square<KING>(~us)];
template<>
ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- Square ksq = pos.square<KING>(pos.side_to_move());
+ Color us = pos.side_to_move();
+ Bitboard pinned = pos.blockers_for_king(us) & pos.pieces(us);
+ Square ksq = pos.square<KING>(us);
ExtMove* cur = moveList;
moveList = pos.checkers() ? generate<EVASIONS >(pos, moveList)
projects / stockfish / blobdiff