/// Version used for pawns, where the 'from' square is given as a delta from the 'to' square
#define SERIALIZE_PAWNS(b, d) while (b) { Square to = pop_1st_bit(&b); \
- (*mlist++).move = make_move(to + (d), to); }
+ (*mlist++).move = make_move(to - (d), to); }
namespace {
enum CastlingSide { KING_SIDE, QUEEN_SIDE };
template<CastlingSide Side, bool OnlyChecks>
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
+ MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO,
Side ? BLACK_OOO : BLACK_OO };
- if (!pos.can_castle(CR[us]))
+ if (pos.castle_impeded(CR[us]) || !pos.can_castle(CR[us]))
return mlist;
// After castling, the rook and king final positions are the same in Chess960
Square kfrom = pos.king_square(us);
Square rfrom = pos.castle_rook_square(CR[us]);
Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
- Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
- Bitboard enemies = pos.pieces(flip(us));
+ Bitboard enemies = pos.pieces(~us);
assert(!pos.in_check());
assert(pos.piece_on(kfrom) == make_piece(us, KING));
assert(pos.piece_on(rfrom) == make_piece(us, ROOK));
- // Unimpeded rule: All the squares between the king's initial and final squares
- // (including the final square), and all the squares between the rook's initial
- // and final squares (including the final square), must be vacant except for
- // the king and castling rook.
- for (Square s = std::min(rfrom, rto), e = std::max(rfrom, rto); s <= e; s++)
- if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- return mlist;
-
for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++)
- if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- ||(pos.attackers_to(s) & enemies))
+ if ( s != kfrom // We are not in check
+ && (pos.attackers_to(s) & enemies))
return mlist;
// 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 (pos.is_chess960())
- {
- Bitboard occ = pos.occupied_squares();
- clear_bit(&occ, rfrom);
- if (pos.attackers_to(kto, occ) & enemies)
+ if ( pos.is_chess960()
+ && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
return mlist;
- }
(*mlist++).move = make_castle(kfrom, rfrom);
template<Square Delta>
inline Bitboard move_pawns(Bitboard 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<Square Delta>
- inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
-
- const Bitboard TFileABB = ( Delta == DELTA_NE
- || Delta == DELTA_SE ? FileABB : FileHBB);
-
- Bitboard b = move_pawns<Delta>(pawns) & target & ~TFileABB;
- SERIALIZE_PAWNS(b, -Delta);
- return mlist;
+ return Delta == DELTA_N ? p << 8
+ : Delta == DELTA_S ? p >> 8
+ : Delta == DELTA_NE ? (p & ~FileHBB) << 9
+ : Delta == DELTA_SE ? (p & ~FileHBB) >> 7
+ : Delta == DELTA_NW ? (p & ~FileABB) << 7
+ : Delta == DELTA_SW ? (p & ~FileABB) >> 9 : 0;
}
template<MoveType Type, Square Delta>
inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) {
- const Bitboard TFileABB = ( Delta == DELTA_NE
- || Delta == DELTA_SE ? FileABB : FileHBB);
-
Bitboard b = move_pawns<Delta>(pawnsOn7) & target;
- if (Delta != DELTA_N && Delta != DELTA_S)
- b &= ~TFileABB;
-
while (b)
{
Square to = pop_1st_bit(&b);
if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
(*mlist++).move = make_promotion(to - Delta, to, QUEEN);
- if (Type == MV_NON_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ if (Type == MV_QUIET || Type == MV_EVASION || Type == MV_NON_EVASION)
{
(*mlist++).move = make_promotion(to - Delta, to, ROOK);
(*mlist++).move = make_promotion(to - Delta, to, BISHOP);
(*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
}
- // Knight-promotion is the only one that can give a check (direct or
- // discovered) not already included in the queen-promotion.
- if (Type == MV_NON_CAPTURE_CHECK && bit_is_set(StepAttacksBB[W_KNIGHT][to], ksq))
+ // Knight-promotion is the only one that can give a direct check not
+ // already included in the queen-promotion.
+ if (Type == MV_QUIET_CHECK && (StepAttacksBB[W_KNIGHT][to] & ksq))
(*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
else
(void)ksq; // 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) {
+ MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq = SQ_NONE) {
- // Calculate our parametrized parameters at compile time, named according to
+ // 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);
// Single and double pawn pushes, no promotions
if (Type != MV_CAPTURE)
{
- emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares());
+ emptySquares = (Type == MV_QUIET ? target : ~pos.pieces());
b1 = move_pawns<UP>(pawnsNotOn7) & emptySquares;
b2 = move_pawns<UP>(b1 & TRank3BB) & emptySquares;
b2 &= target;
}
- if (Type == MV_NON_CAPTURE_CHECK)
+ if (Type == MV_QUIET_CHECK)
{
- // Consider only direct checks
b1 &= pos.attacks_from<PAWN>(ksq, Them);
b2 &= pos.attacks_from<PAWN>(ksq, Them);
}
}
- SERIALIZE_PAWNS(b1, -UP);
- SERIALIZE_PAWNS(b2, -UP -UP);
+ SERIALIZE_PAWNS(b1, UP);
+ SERIALIZE_PAWNS(b2, UP + UP);
}
// Promotions and underpromotions
- if (pawnsOn7)
+ if (pawnsOn7 && (Type != MV_EVASION || (target & TRank8BB)))
{
if (Type == MV_CAPTURE)
- emptySquares = pos.empty_squares();
+ emptySquares = ~pos.pieces();
if (Type == MV_EVASION)
emptySquares &= target;
// Standard and en-passant captures
if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
{
- mlist = generate_pawn_captures<RIGHT>(mlist, pawnsNotOn7, enemies);
- mlist = generate_pawn_captures<LEFT >(mlist, pawnsNotOn7, enemies);
+ b1 = move_pawns<RIGHT>(pawnsNotOn7) & enemies;
+ b2 = move_pawns<LEFT >(pawnsNotOn7) & enemies;
+
+ SERIALIZE_PAWNS(b1, RIGHT);
+ SERIALIZE_PAWNS(b2, LEFT);
if (pos.ep_square() != SQ_NONE)
{
- assert(rank_of(pos.ep_square()) == (Us == WHITE ? RANK_6 : RANK_3));
+ assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6));
// An en passant capture can be an evasion only if the checking piece
// is the double pushed pawn and so is in the target. Otherwise this
// is a discovery check and we are forced to do otherwise.
- if (Type == MV_EVASION && !bit_is_set(target, pos.ep_square() - UP))
+ if (Type == MV_EVASION && !(target & (pos.ep_square() - UP)))
return mlist;
b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
template<PieceType Pt>
- inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
- Bitboard dc, Square ksq) {
+ inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist,
+ Color us, const CheckInfo& ci) {
assert(Pt != KING && Pt != PAWN);
- Bitboard checkSqs, b;
+ Bitboard b, target;
Square from;
const Square* pl = pos.piece_list(us, Pt);
- if ((from = *pl++) == SQ_NONE)
- return mlist;
-
- checkSqs = pos.attacks_from<Pt>(ksq) & pos.empty_squares();
-
- do
+ if (*pl != SQ_NONE)
{
- if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
- || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs))
- || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
- continue;
-
- if (dc && bit_is_set(dc, from))
- continue;
-
- b = pos.attacks_from<Pt>(from) & checkSqs;
- SERIALIZE(b);
+ target = ci.checkSq[Pt] & ~pos.pieces(); // Non capture checks only
- } while ((from = *pl++) != SQ_NONE);
-
- return mlist;
- }
-
-
- template<>
- FORCE_INLINE MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
+ do {
+ from = *pl;
- return us == WHITE ? generate_pawn_moves<WHITE, MV_NON_CAPTURE_CHECK>(p, m, dc, ksq)
- : generate_pawn_moves<BLACK, MV_NON_CAPTURE_CHECK>(p, m, dc, ksq);
- }
+ if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
+ && !(PseudoAttacks[Pt][from] & target))
+ continue;
+ if (ci.dcCandidates && (ci.dcCandidates & from))
+ continue;
- template<PieceType Pt, MoveType Type>
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
+ b = pos.attacks_from<Pt>(from) & target;
+ SERIALIZE(b);
+ } while (*++pl != SQ_NONE);
+ }
- assert(Pt == PAWN);
- return us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m, t, SQ_NONE)
- : generate_pawn_moves<BLACK, Type>(p, m, t, SQ_NONE);
+ return mlist;
}
template<PieceType Pt>
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+ FORCE_INLINE MoveStack* generate_moves(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target) {
+ assert(Pt != KING && Pt != PAWN);
Bitboard b;
Square from;
const Square* pl = pos.piece_list(us, Pt);
if (*pl != SQ_NONE)
- {
do {
from = *pl;
b = pos.attacks_from<Pt>(from) & target;
SERIALIZE(b);
} while (*++pl != SQ_NONE);
- }
+
return mlist;
}
template<>
- FORCE_INLINE MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
-
+ FORCE_INLINE MoveStack* generate_moves<KING>(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target) {
Square from = pos.king_square(us);
Bitboard b = pos.attacks_from<KING>(from) & target;
SERIALIZE(b);
/// generate<MV_CAPTURE> generates all pseudo-legal captures and queen
/// promotions. Returns a pointer to the end of the move list.
///
-/// generate<MV_NON_CAPTURE> generates all pseudo-legal non-captures and
+/// generate<MV_QUIET> generates all pseudo-legal non-captures and
/// underpromotions. Returns a pointer to the end of the move list.
///
/// generate<MV_NON_EVASION> generates all pseudo-legal captures and
template<MoveType Type>
MoveStack* generate(const Position& pos, MoveStack* mlist) {
- assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_NON_EVASION);
+ assert(Type == MV_CAPTURE || Type == MV_QUIET || Type == MV_NON_EVASION);
assert(!pos.in_check());
Color us = pos.side_to_move();
Bitboard target;
if (Type == MV_CAPTURE)
- target = pos.pieces(flip(us));
+ target = pos.pieces(~us);
- else if (Type == MV_NON_CAPTURE)
- target = pos.empty_squares();
+ else if (Type == MV_QUIET)
+ target = ~pos.pieces();
else if (Type == MV_NON_EVASION)
- target = pos.pieces(flip(us)) | pos.empty_squares();
+ target = ~pos.pieces(us);
+
+ mlist = (us == WHITE ? generate_pawn_moves<WHITE, Type>(pos, mlist, target)
+ : generate_pawn_moves<BLACK, Type>(pos, mlist, target));
- mlist = generate_piece_moves<PAWN, Type>(pos, mlist, us, target);
- 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_moves<KNIGHT>(pos, mlist, us, target);
+ mlist = generate_moves<BISHOP>(pos, mlist, us, target);
+ mlist = generate_moves<ROOK>(pos, mlist, us, target);
+ mlist = generate_moves<QUEEN>(pos, mlist, us, target);
+ mlist = generate_moves<KING>(pos, mlist, us, target);
if (Type != MV_CAPTURE && pos.can_castle(us))
{
- mlist = generate_castle_moves<KING_SIDE, false>(pos, mlist, us);
- mlist = generate_castle_moves<QUEEN_SIDE, false>(pos, mlist, us);
+ mlist = generate_castle<KING_SIDE, false>(pos, mlist, us);
+ mlist = generate_castle<QUEEN_SIDE, false>(pos, mlist, us);
}
return mlist;
// Explicit template instantiations
template MoveStack* generate<MV_CAPTURE>(const Position& pos, MoveStack* mlist);
-template MoveStack* generate<MV_NON_CAPTURE>(const Position& pos, MoveStack* mlist);
+template MoveStack* generate<MV_QUIET>(const Position& pos, MoveStack* mlist);
template MoveStack* generate<MV_NON_EVASION>(const Position& pos, MoveStack* mlist);
-/// generate<MV_NON_CAPTURE_CHECK> generates all pseudo-legal non-captures and knight
+/// generate<MV_QUIET_CHECK> generates all pseudo-legal non-captures and knight
/// underpromotions that give check. Returns a pointer to the end of the move list.
template<>
-MoveStack* generate<MV_NON_CAPTURE_CHECK>(const Position& pos, MoveStack* mlist) {
+MoveStack* generate<MV_QUIET_CHECK>(const Position& pos, MoveStack* mlist) {
assert(!pos.in_check());
- Bitboard b, dc;
- Square from;
- PieceType pt;
Color us = pos.side_to_move();
- Square ksq = pos.king_square(flip(us));
-
- assert(pos.piece_on(ksq) == make_piece(flip(us), KING));
+ CheckInfo ci(pos);
+ Bitboard dc = ci.dcCandidates;
- b = dc = pos.discovered_check_candidates();
-
- while (b)
+ while (dc)
{
- from = pop_1st_bit(&b);
- pt = type_of(pos.piece_on(from));
+ Square from = pop_1st_bit(&dc);
+ PieceType pt = type_of(pos.piece_on(from));
if (pt == PAWN)
continue; // Will be generated togheter with direct checks
- b = pos.attacks_from(Piece(pt), from) & pos.empty_squares();
+ Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
if (pt == KING)
- b &= ~QueenPseudoAttacks[ksq];
+ b &= ~PseudoAttacks[QUEEN][ci.ksq];
SERIALIZE(b);
}
- mlist = generate_direct_checks<PAWN>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<BISHOP>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<ROOK>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<QUEEN>(pos, mlist, us, dc, ksq);
+ mlist = (us == WHITE ? generate_pawn_moves<WHITE, MV_QUIET_CHECK>(pos, mlist, ci.dcCandidates, ci.ksq)
+ : generate_pawn_moves<BLACK, MV_QUIET_CHECK>(pos, mlist, ci.dcCandidates, ci.ksq));
+
+ mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<BISHOP>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<ROOK>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<QUEEN>(pos, mlist, us, ci);
if (pos.can_castle(us))
{
- mlist = generate_castle_moves<KING_SIDE, true>(pos, mlist, us);
- mlist = generate_castle_moves<QUEEN_SIDE, true>(pos, mlist, us);
+ mlist = generate_castle<KING_SIDE, true>(pos, mlist, us);
+ mlist = generate_castle<QUEEN_SIDE, true>(pos, mlist, us);
}
return mlist;
int checkersCnt = 0;
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
- Bitboard checkers = pos.checkers();
Bitboard sliderAttacks = 0;
+ Bitboard checkers = pos.checkers();
- assert(pos.piece_on(ksq) == make_piece(us, KING));
assert(checkers);
// Find squares attacked by slider checkers, we will remove them from the king
- // evasions set so to skip known illegal moves and avoid to do legality check later.
+ // evasions so to skip known illegal moves avoiding useless legality check later.
b = checkers;
do
{
checkersCnt++;
checksq = pop_1st_bit(&b);
- assert(color_of(pos.piece_on(checksq)) == flip(us));
+ assert(color_of(pos.piece_on(checksq)) == ~us);
switch (type_of(pos.piece_on(checksq)))
{
- case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break;
- case ROOK: sliderAttacks |= RookPseudoAttacks[checksq]; break;
+ case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break;
+ case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break;
case QUEEN:
- // If queen and king are far we can safely remove all the squares attacked
- // in the other direction becuase are not reachable by the king anyway.
- if (squares_between(ksq, checksq) || (RookPseudoAttacks[checksq] & (1ULL << ksq)))
- sliderAttacks |= QueenPseudoAttacks[checksq];
-
- // Otherwise, if king and queen are adjacent and on a diagonal line, we need to
- // use real rook attacks to check if king is safe to move in the other direction.
- // For example: king in B2, queen in A1 a knight in B1, and we can safely move to C1.
+ // If queen and king are far or not on a diagonal line we can safely
+ // remove all the squares attacked in the other direction becuase are
+ // not reachable by the king anyway.
+ if (squares_between(ksq, checksq) || !(PseudoAttacks[BISHOP][checksq] & ksq))
+ sliderAttacks |= PseudoAttacks[QUEEN][checksq];
+
+ // Otherwise we need to use real rook attacks to check if king is safe
+ // to move in the other direction. For example: king in B2, queen in A1
+ // a knight in B1, and we can safely move to C1.
else
- sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from<ROOK>(checksq);
+ sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from<ROOK>(checksq);
default:
break;
if (checkersCnt > 1)
return mlist;
- // Target for blocking evasions or captures of the checking piece
+ // Blocking evasions or captures of the checking piece
target = squares_between(checksq, ksq) | checkers;
- mlist = generate_piece_moves<PAWN, MV_EVASION>(pos, mlist, us, target);
- 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);
- return generate_piece_moves<QUEEN>(pos, mlist, us, target);
+ mlist = (us == WHITE ? generate_pawn_moves<WHITE, MV_EVASION>(pos, mlist, target)
+ : generate_pawn_moves<BLACK, MV_EVASION>(pos, mlist, target));
+
+ mlist = generate_moves<KNIGHT>(pos, mlist, us, target);
+ mlist = generate_moves<BISHOP>(pos, mlist, us, target);
+ mlist = generate_moves<ROOK>(pos, mlist, us, target);
+ return generate_moves<QUEEN>(pos, mlist, us, target);
}