/*
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) 2004-2021 The Stockfish developers (see AUTHORS file)
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, const CheckInfo* ci) {
-
- 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.king_square(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, *ci))
- return moveList;
-
- (moveList++)->move = m;
-
- return moveList;
- }
-
-
- template<GenType Type, Square Delta>
- inline ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) {
+ template<GenType Type, Direction D>
+ ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) {
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
- (moveList++)->move = make<PROMOTION>(to - Delta, to, QUEEN);
+ {
+ *moveList++ = make<PROMOTION>(to - D, to, QUEEN);
+ if (attacks_bb<KNIGHT>(to) & ksq)
+ *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
+ }
if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
- (moveList++)->move = make<PROMOTION>(to - Delta, to, ROOK);
- (moveList++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
- (moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
+ *moveList++ = make<PROMOTION>(to - D, to, ROOK);
+ *moveList++ = make<PROMOTION>(to - D, to, BISHOP);
+ if (!(attacks_bb<KNIGHT>(to) & ksq))
+ *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] & ci->ksq))
- (moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
- else
- (void)ci; // Silence a warning under MSVC
-
return moveList;
}
template<Color Us, GenType Type>
- ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList,
- Bitboard target, const CheckInfo* ci) {
-
- // 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);
+ ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
+
+ constexpr Color Them = ~Us;
+ constexpr Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+ constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ 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;
{
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 (Type == QUIET_CHECKS)
{
- b1 &= pos.attacks_from<PAWN>(ci->ksq, Them);
- b2 &= pos.attacks_from<PAWN>(ci->ksq, Them);
+ b1 &= pawn_attacks_bb(Them, ksq);
+ b2 &= pawn_attacks_bb(Them, ksq);
// Add pawn pushes which give 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. Note that a possible discovery check
+ // don't generate captures. Note that a possible discovered check
// promotion has been already generated amongst the captures.
- if (pawnsNotOn7 & ci->dcCandidates)
+ Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7;
+ if (dcCandidateQuiets)
{
- Bitboard dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->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;
while (b1)
{
Square to = pop_lsb(&b1);
- (moveList++)->move = make_move(to - Up, to);
+ *moveList++ = make_move(to - Up, to);
}
while (b2)
{
Square to = pop_lsb(&b2);
- (moveList++)->move = make_move(to - Up - Up, to);
+ *moveList++ = make_move(to - Up - Up, to);
}
}
// 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;
while (b1)
- moveList = make_promotions<Type, Right>(moveList, pop_lsb(&b1), ci);
+ moveList = make_promotions<Type, UpRight>(moveList, pop_lsb(&b1), ksq);
while (b2)
- moveList = make_promotions<Type, Left >(moveList, pop_lsb(&b2), ci);
+ moveList = make_promotions<Type, UpLeft >(moveList, pop_lsb(&b2), ksq);
while (b3)
- moveList = make_promotions<Type, Up >(moveList, pop_lsb(&b3), ci);
+ moveList = make_promotions<Type, Up >(moveList, pop_lsb(&b3), ksq);
}
- // Standard and en-passant captures
+ // 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++)->move = make_move(to - Right, to);
+ *moveList++ = make_move(to - UpRight, to);
}
while (b2)
{
Square to = pop_lsb(&b2);
- (moveList++)->move = make_move(to - Left, to);
+ *moveList++ = make_move(to - UpLeft, to);
}
if (pos.ep_square() != SQ_NONE)
if (Type == EVASIONS && !(target & (pos.ep_square() - Up)))
return moveList;
- b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
+ b1 = pawnsNotOn7 & pawn_attacks_bb(Them, pos.ep_square());
assert(b1);
while (b1)
- (moveList++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
+ *moveList++ = make<EN_PASSANT>(pop_lsb(&b1), pos.ep_square());
}
}
}
- template<PieceType Pt, bool Checks> FORCE_INLINE
- ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
- Bitboard target, const CheckInfo* ci) {
+ template<PieceType Pt, bool Checks>
+ ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard piecesToMove, Bitboard target) {
- assert(Pt != KING && Pt != PAWN);
+ static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()");
- const Square* pl = pos.list<Pt>(us);
+ Bitboard bb = piecesToMove & pos.pieces(Pt);
- for (Square from = *pl; from != SQ_NONE; from = *++pl)
- {
- if (Checks)
- {
- if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
- && !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
- continue;
+ while (bb) {
+ Square from = pop_lsb(&bb);
- if (ci->dcCandidates && (ci->dcCandidates & from))
- continue;
- }
+ if (Checks && (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
+ && !(attacks_bb<Pt>(from) & target & pos.check_squares(Pt)))
+ continue;
- Bitboard b = pos.attacks_from<Pt>(from) & target;
+ Bitboard b = attacks_bb<Pt>(from, pos.pieces()) & target;
if (Checks)
- b &= ci->checkSq[Pt];
+ b &= pos.check_squares(Pt);
while (b)
- (moveList++)->move = make_move(from, pop_lsb(&b));
+ *moveList++ = make_move(from, pop_lsb(&b));
}
return moveList;
}
- template<Color Us, GenType Type> FORCE_INLINE
- ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target,
- const CheckInfo* ci = nullptr) {
+ template<Color Us, GenType Type>
+ ExtMove* generate_all(const Position& pos, ExtMove* moveList) {
- const bool Checks = Type == QUIET_CHECKS;
+ static_assert(Type != LEGAL, "Unsupported type in generate_all()");
- moveList = generate_pawn_moves<Us, Type>(pos, moveList, target, ci);
- moveList = generate_moves<KNIGHT, Checks>(pos, moveList, Us, target, ci);
- moveList = generate_moves<BISHOP, Checks>(pos, moveList, Us, target, ci);
- moveList = generate_moves< ROOK, Checks>(pos, moveList, Us, target, ci);
- moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target, ci);
+ constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantations
+ Bitboard target, piecesToMove = pos.pieces(Us);
- if (Type != QUIET_CHECKS && Type != EVASIONS)
- {
- Square ksq = pos.king_square(Us);
- Bitboard b = pos.attacks_from<KING>(ksq) & target;
- while (b)
- (moveList++)->move = make_move(ksq, pop_lsb(&b));
- }
+ if(Type == QUIET_CHECKS)
+ piecesToMove &= ~pos.blockers_for_king(~Us);
- if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us))
+ switch (Type)
{
- if (pos.is_chess960())
+ case CAPTURES:
+ target = pos.pieces(~Us);
+ break;
+ case QUIETS:
+ case QUIET_CHECKS:
+ target = ~pos.pieces();
+ break;
+ case EVASIONS:
{
- moveList = generate_castling<MakeCastling<Us, KING_SIDE>::right, Checks, true>(pos, moveList, Us, ci);
- moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, true>(pos, moveList, Us, ci);
- }
- else
- {
- moveList = generate_castling<MakeCastling<Us, KING_SIDE>::right, Checks, false>(pos, moveList, Us, ci);
- moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, false>(pos, moveList, Us, ci);
+ Square checksq = lsb(pos.checkers());
+ target = between_bb(pos.square<KING>(Us), checksq) | checksq;
+ break;
}
+ case NON_EVASIONS:
+ target = ~pos.pieces(Us);
+ break;
+ }
+
+ moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
+ moveList = generate_moves<KNIGHT, Checks>(pos, moveList, piecesToMove, target);
+ moveList = generate_moves<BISHOP, Checks>(pos, moveList, piecesToMove, target);
+ moveList = generate_moves< ROOK, Checks>(pos, moveList, piecesToMove, target);
+ moveList = generate_moves< QUEEN, Checks>(pos, moveList, piecesToMove, target);
+
+ if (Type != QUIET_CHECKS && Type != EVASIONS)
+ {
+ Square ksq = pos.square<KING>(Us);
+ Bitboard b = attacks_bb<KING>(ksq) & target;
+ while (b)
+ *moveList++ = make_move(ksq, pop_lsb(&b));
+
+ if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING))
+ for (CastlingRights cr : { Us & KING_SIDE, Us & QUEEN_SIDE } )
+ if (!pos.castling_impeded(cr) && pos.can_castle(cr))
+ *moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(cr));
}
return moveList;
} // 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 plus queen and checking knight promotions
+/// <QUIETS> Generates all pseudo-legal non-captures and underpromotions(except checking knight)
+/// <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();
- Bitboard target = Type == CAPTURES ? pos.pieces(~us)
- : Type == QUIETS ? ~pos.pieces()
- : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
-
- return us == WHITE ? generate_all<WHITE, Type>(pos, moveList, target)
- : generate_all<BLACK, Type>(pos, moveList, target);
+ return us == WHITE ? generate_all<WHITE, Type>(pos, moveList)
+ : generate_all<BLACK, Type>(pos, moveList);
}
// Explicit template instantiations
template ExtMove* generate<NON_EVASIONS>(const Position&, ExtMove*);
-/// generate<QUIET_CHECKS> generates all pseudo-legal non-captures and knight
-/// underpromotions that give check. Returns a pointer to the end of the move list.
+/// generate<QUIET_CHECKS> generates all pseudo-legal non-captures.
+/// Returns a pointer to the end of the move list.
template<>
ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
assert(!pos.checkers());
Color us = pos.side_to_move();
- CheckInfo ci(pos);
- Bitboard dc = ci.dcCandidates;
+ Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us) & ~pos.pieces(PAWN);
while (dc)
{
Square from = pop_lsb(&dc);
PieceType pt = type_of(pos.piece_on(from));
- if (pt == PAWN)
- continue; // Will be generated together with direct checks
-
- Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
+ Bitboard b = attacks_bb(pt, from, pos.pieces()) & ~pos.pieces();
if (pt == KING)
- b &= ~PseudoAttacks[QUEEN][ci.ksq];
+ b &= ~attacks_bb<QUEEN>(pos.square<KING>(~us));
while (b)
- (moveList++)->move = make_move(from, pop_lsb(&b));
+ *moveList++ = make_move(from, pop_lsb(&b));
}
- return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci)
- : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci);
+ return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList)
+ : generate_all<BLACK, QUIET_CHECKS>(pos, moveList);
}
assert(pos.checkers());
Color us = pos.side_to_move();
- Square ksq = pos.king_square(us);
+ Square ksq = pos.square<KING>(us);
Bitboard sliderAttacks = 0;
Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN);
// the king evasions in order to skip known illegal moves, which avoids any
// useless legality checks later on.
while (sliders)
- {
- Square checksq = pop_lsb(&sliders);
- sliderAttacks |= LineBB[checksq][ksq] ^ checksq;
- }
+ sliderAttacks |= line_bb(ksq, pop_lsb(&sliders)) & ~pos.checkers();
// Generate evasions for king, capture and non capture moves
- Bitboard b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
+ Bitboard b = attacks_bb<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
while (b)
- (moveList++)->move = make_move(ksq, pop_lsb(&b));
+ *moveList++ = make_move(ksq, pop_lsb(&b));
if (more_than_one(pos.checkers()))
return moveList; // Double check, only a king move can save the day
// Generate blocking evasions or captures of the checking piece
- Square checksq = lsb(pos.checkers());
- Bitboard target = between_bb(checksq, ksq) | checksq;
-
- return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList, target)
- : generate_all<BLACK, EVASIONS>(pos, moveList, target);
+ return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList)
+ : generate_all<BLACK, EVASIONS>(pos, moveList);
}
template<>
ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- Square ksq = pos.king_square(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)
: generate<NON_EVASIONS>(pos, moveList);
while (cur != moveList)
- if ( (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
- && !pos.legal(cur->move, pinned))
- cur->move = (--moveList)->move;
+ if ( (pinned || from_sq(*cur) == ksq || type_of(*cur) == EN_PASSANT)
+ && !pos.legal(*cur))
+ *cur = (--moveList)->move;
else
++cur;
projects / stockfish / blobdiff