along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <algorithm>
#include <cassert>
#include "movegen.h"
(*mlist++).move = make_move(to - (d), to); }
namespace {
- template<CastlingSide Side, bool OnlyChecks>
+ template<CastlingSide Side, bool Checks, bool Chess960>
MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
if (pos.castle_impeded(us, Side) || !pos.can_castle(make_castle_right(us, Side)))
Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
Bitboard enemies = pos.pieces(~us);
- assert(!pos.in_check());
+ assert(!pos.checkers());
- for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++)
- if ( s != kfrom // We are not in check
- && (pos.attackers_to(s) & enemies))
+ const int K = Chess960 ? kto > kfrom ? -1 : 1
+ : Side == KING_SIDE ? -1 : 1;
+
+ for (Square s = kto; s != kfrom; s += (Square)K)
+ if (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()
- && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
- return mlist;
+ if (Chess960 && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
+ return mlist;
(*mlist++).move = make<CASTLE>(kfrom, rfrom);
- if (OnlyChecks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
+ if (Checks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
mlist--;
return mlist;
template<GenType Type, Square Delta>
- inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) {
+ inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7,
+ Bitboard target, const CheckInfo* ci) {
Bitboard b = move_pawns<Delta>(pawnsOn7) & target;
// Knight-promotion is the only one that can give a direct check not
// already included in the queen-promotion.
- if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ksq))
+ if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
(*mlist++).move = make<PROMOTION>(to - Delta, to, KNIGHT);
else
- (void)ksq; // Silence a warning under MSVC
+ (void)ci; // Silence a warning under MSVC
}
return mlist;
template<Color Us, GenType Type>
- MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq = SQ_NONE) {
+ MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist,
+ Bitboard target, const CheckInfo* ci) {
// Compute our parametrized parameters at compile time, named according to
// the point of view of white side.
// Single and double pawn pushes, no promotions
if (Type != CAPTURES)
{
- emptySquares = (Type == QUIETS ? target : ~pos.pieces());
+ emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
b1 = move_pawns<UP>(pawnsNotOn7) & emptySquares;
b2 = move_pawns<UP>(b1 & TRank3BB) & emptySquares;
if (Type == QUIET_CHECKS)
{
- b1 &= pos.attacks_from<PAWN>(ksq, Them);
- b2 &= pos.attacks_from<PAWN>(ksq, Them);
+ b1 &= pos.attacks_from<PAWN>(ci->ksq, Them);
+ b2 &= pos.attacks_from<PAWN>(ci->ksq, Them);
// 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
// promotion has been already generated among captures.
- if (pawnsNotOn7 & target) // Target is dc bitboard
+ if (pawnsNotOn7 & ci->dcCandidates)
{
- dc1 = move_pawns<UP>(pawnsNotOn7 & target) & emptySquares & ~file_bb(ksq);
+ dc1 = move_pawns<UP>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
b1 |= dc1;
if (Type == EVASIONS)
emptySquares &= target;
- mlist = generate_promotions<Type, RIGHT>(mlist, pawnsOn7, enemies, ksq);
- mlist = generate_promotions<Type, LEFT>(mlist, pawnsOn7, enemies, ksq);
- mlist = generate_promotions<Type, UP>(mlist, pawnsOn7, emptySquares, ksq);
+ mlist = generate_promotions<Type, RIGHT>(mlist, pawnsOn7, enemies, ci);
+ mlist = generate_promotions<Type, LEFT>(mlist, pawnsOn7, enemies, ci);
+ mlist = generate_promotions<Type, UP>(mlist, pawnsOn7, emptySquares, ci);
}
// Standard and en-passant captures
}
- template<PieceType Pt, bool OnlyChecks> FORCE_INLINE
+ template<PieceType Pt, bool Checks> FORCE_INLINE
MoveStack* generate_moves(const Position& pos, MoveStack* mlist, Color us,
- Bitboard target, const CheckInfo* ci = NULL) {
+ Bitboard target, const CheckInfo* ci) {
assert(Pt != KING && Pt != PAWN);
for (Square from = *pl; from != SQ_NONE; from = *++pl)
{
- if (OnlyChecks)
+ if (Checks)
{
if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
&& !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
Bitboard b = pos.attacks_from<Pt>(from) & target;
- if (OnlyChecks)
+ if (Checks)
b &= ci->checkSq[Pt];
SERIALIZE(b);
return mlist;
}
- template<> FORCE_INLINE
- MoveStack* generate_moves<KING, false>(const Position& pos, MoveStack* mlist, Color us,
- Bitboard target, const CheckInfo*) {
- Square from = pos.king_square(us);
- Bitboard b = pos.attacks_from<KING>(from) & target;
- SERIALIZE(b);
+
+ template<GenType Type> FORCE_INLINE
+ MoveStack* generate_all(const Position& pos, MoveStack* mlist, Color us,
+ Bitboard target, const CheckInfo* ci = NULL) {
+
+ const bool Checks = Type == QUIET_CHECKS;
+
+ mlist = (us == WHITE ? generate_pawn_moves<WHITE, Type>(pos, mlist, target, ci)
+ : generate_pawn_moves<BLACK, Type>(pos, mlist, target, ci));
+
+ mlist = generate_moves<KNIGHT, Checks>(pos, mlist, us, target, ci);
+ mlist = generate_moves<BISHOP, Checks>(pos, mlist, us, target, ci);
+ mlist = generate_moves<ROOK, Checks>(pos, mlist, us, target, ci);
+ mlist = generate_moves<QUEEN, Checks>(pos, mlist, us, target, ci);
+
+ if (Type != QUIET_CHECKS && Type != EVASIONS)
+ {
+ Square from = pos.king_square(us);
+ Bitboard b = pos.attacks_from<KING>(from) & target;
+ SERIALIZE(b);
+ }
+
+ if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(us))
+ {
+ if (pos.is_chess960())
+ {
+ mlist = generate_castle<KING_SIDE, Checks, true>(pos, mlist, us);
+ mlist = generate_castle<QUEEN_SIDE, Checks, true>(pos, mlist, us);
+ }
+ else
+ {
+ mlist = generate_castle<KING_SIDE, Checks, false>(pos, mlist, us);
+ mlist = generate_castle<QUEEN_SIDE, Checks, false>(pos, mlist, us);
+ }
+ }
+
return mlist;
}
+
} // namespace
MoveStack* generate(const Position& pos, MoveStack* mlist) {
assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
- assert(!pos.in_check());
+ assert(!pos.checkers());
Color us = pos.side_to_move();
- Bitboard target;
-
- if (Type == CAPTURES)
- target = pos.pieces(~us);
-
- else if (Type == QUIETS)
- target = ~pos.pieces();
- else if (Type == NON_EVASIONS)
- target = ~pos.pieces(us);
+ Bitboard target = Type == CAPTURES ? pos.pieces(~us)
+ : Type == QUIETS ? ~pos.pieces()
+ : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
- mlist = (us == WHITE ? generate_pawn_moves<WHITE, Type>(pos, mlist, target)
- : generate_pawn_moves<BLACK, Type>(pos, mlist, target));
-
- mlist = generate_moves<KNIGHT, false>(pos, mlist, us, target);
- mlist = generate_moves<BISHOP, false>(pos, mlist, us, target);
- mlist = generate_moves<ROOK, false>(pos, mlist, us, target);
- mlist = generate_moves<QUEEN, false>(pos, mlist, us, target);
- mlist = generate_moves<KING, false>(pos, mlist, us, target);
-
- if (Type != CAPTURES && pos.can_castle(us))
- {
- mlist = generate_castle<KING_SIDE, false>(pos, mlist, us);
- mlist = generate_castle<QUEEN_SIDE, false>(pos, mlist, us);
- }
-
- return mlist;
+ return generate_all<Type>(pos, mlist, us, target);
}
// Explicit template instantiations
-template MoveStack* generate<CAPTURES>(const Position& pos, MoveStack* mlist);
-template MoveStack* generate<QUIETS>(const Position& pos, MoveStack* mlist);
-template MoveStack* generate<NON_EVASIONS>(const Position& pos, MoveStack* mlist);
+template MoveStack* generate<CAPTURES>(const Position&, MoveStack*);
+template MoveStack* generate<QUIETS>(const Position&, MoveStack*);
+template MoveStack* generate<NON_EVASIONS>(const Position&, MoveStack*);
/// generate<QUIET_CHECKS> generates all pseudo-legal non-captures and knight
template<>
MoveStack* generate<QUIET_CHECKS>(const Position& pos, MoveStack* mlist) {
- assert(!pos.in_check());
+ assert(!pos.checkers());
- Color us = pos.side_to_move();
CheckInfo ci(pos);
- Bitboard empty = ~pos.pieces();
Bitboard dc = ci.dcCandidates;
while (dc)
SERIALIZE(b);
}
- mlist = (us == WHITE ? generate_pawn_moves<WHITE, QUIET_CHECKS>(pos, mlist, ci.dcCandidates, ci.ksq)
- : generate_pawn_moves<BLACK, QUIET_CHECKS>(pos, mlist, ci.dcCandidates, ci.ksq));
-
- mlist = generate_moves<KNIGHT, true>(pos, mlist, us, empty, &ci);
- mlist = generate_moves<BISHOP, true>(pos, mlist, us, empty, &ci);
- mlist = generate_moves<ROOK, true>(pos, mlist, us, empty, &ci);
- mlist = generate_moves<QUEEN, true>(pos, mlist, us, empty, &ci);
-
- if (pos.can_castle(us))
- {
- mlist = generate_castle<KING_SIDE, true>(pos, mlist, us);
- mlist = generate_castle<QUEEN_SIDE, true>(pos, mlist, us);
- }
-
- return mlist;
+ return generate_all<QUIET_CHECKS>(pos, mlist, pos.side_to_move(), ~pos.pieces(), &ci);
}
template<>
MoveStack* generate<EVASIONS>(const Position& pos, MoveStack* mlist) {
- assert(pos.in_check());
+ assert(pos.checkers());
- Bitboard b, target;
Square from, checksq;
int checkersCnt = 0;
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
Bitboard sliderAttacks = 0;
- Bitboard checkers = pos.checkers();
+ Bitboard b = pos.checkers();
- assert(checkers);
+ assert(pos.checkers());
// Find squares attacked by slider checkers, we will remove them from the king
// evasions so to skip known illegal moves avoiding useless legality check later.
- b = checkers;
do
{
checkersCnt++;
from = ksq;
SERIALIZE(b);
- // Generate evasions for other pieces only if not under a double check
if (checkersCnt > 1)
- return mlist;
-
- // Blocking evasions or captures of the checking piece
- target = between_bb(checksq, ksq) | checkers;
+ return mlist; // Double check, only a king move can save the day
- mlist = (us == WHITE ? generate_pawn_moves<WHITE, EVASIONS>(pos, mlist, target)
- : generate_pawn_moves<BLACK, EVASIONS>(pos, mlist, target));
+ // Generate blocking evasions or captures of the checking piece
+ Bitboard target = between_bb(checksq, ksq) | pos.checkers();
- mlist = generate_moves<KNIGHT, false>(pos, mlist, us, target);
- mlist = generate_moves<BISHOP, false>(pos, mlist, us, target);
- mlist = generate_moves<ROOK, false>(pos, mlist, us, target);
- return generate_moves<QUEEN, false>(pos, mlist, us, target);
+ return generate_all<EVASIONS>(pos, mlist, us, target);
}
MoveStack *end, *cur = mlist;
Bitboard pinned = pos.pinned_pieces();
+ Square ksq = pos.king_square(pos.side_to_move());
- end = pos.in_check() ? generate<EVASIONS>(pos, mlist)
+ end = pos.checkers() ? generate<EVASIONS>(pos, mlist)
: generate<NON_EVASIONS>(pos, mlist);
while (cur != end)
- if (!pos.pl_move_is_legal(cur->move, pinned))
+ if ( (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
+ && !pos.pl_move_is_legal(cur->move, pinned))
cur->move = (--end)->move;
else
cur++;