X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=cc1518a078de7d48064e93cbd23e8ad6b95b54be;hp=c9255f31eb4e5245b867c0694d2d358a72dc77a0;hb=HEAD;hpb=37d551fb39a4e631946156fcb76cde7fcde37ba4
diff --git a/src/movegen.cpp b/src/movegen.cpp
index c9255f31..7d6856bb 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -1,7 +1,6 @@
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2004-2023 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
@@ -17,533 +16,265 @@
along with this program. If not, see .
*/
-#include
-
-#include "bitcount.h"
#include "movegen.h"
-// Simple macro to wrap a very common while loop, no facny, no flexibility,
-// hardcoded list name 'mlist' and from square 'from'.
-#define SERIALIZE_MOVES(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b))
-
-// Version used for pawns, where the 'from' square is given as a delta from the 'to' square
-#define SERIALIZE_MOVES_D(b, d) while (b) { to = pop_1st_bit(&b); (*mlist++).move = make_move(to + (d), to); }
+#include
+#include
-namespace {
+#include "bitboard.h"
+#include "position.h"
- enum CastlingSide {
- KING_SIDE,
- QUEEN_SIDE
- };
+namespace Stockfish {
- template
- MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us);
+namespace {
- template
- MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square);
+template
+ExtMove* make_promotions(ExtMove* moveList, [[maybe_unused]] Square to) {
- template
- inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) {
+ constexpr bool all = Type == EVASIONS || Type == NON_EVASIONS;
- assert(Pt != QUEEN);
- assert(Pt != PAWN);
+ if constexpr (Type == CAPTURES || all)
+ *moveList++ = make(to - D, to, QUEEN);
- Bitboard b = pos.attacks_from(from) & pos.empty_squares();
+ if constexpr ((Type == CAPTURES && Enemy) || (Type == QUIETS && !Enemy) || all)
+ {
+ *moveList++ = make(to - D, to, ROOK);
+ *moveList++ = make(to - D, to, BISHOP);
+ *moveList++ = make(to - D, to, KNIGHT);
+ }
- if (Pt == KING)
- b &= ~QueenPseudoAttacks[pos.king_square(opposite_color(pos.side_to_move()))];
+ return moveList;
+}
- SERIALIZE_MOVES(b);
- return mlist;
- }
- template
- inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
- Bitboard dc, Square ksq) {
- assert(Pt != KING);
- assert(Pt != PAWN);
+template
+ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
- Bitboard checkSqs, b;
- Square from;
- const Square* pl = pos.piece_list(us, Pt);
+ 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);
- if ((from = *pl++) == SQ_NONE)
- return mlist;
+ const Bitboard emptySquares = ~pos.pieces();
+ const Bitboard enemies = Type == EVASIONS ? pos.checkers() : pos.pieces(Them);
- checkSqs = pos.attacks_from(ksq) & pos.empty_squares();
+ Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB;
+ Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
- do
+ // Single and double pawn pushes, no promotions
+ if constexpr (Type != CAPTURES)
{
- 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(from) & checkSqs;
- SERIALIZE_MOVES(b);
+ Bitboard b1 = shift(pawnsNotOn7) & emptySquares;
+ Bitboard b2 = shift(b1 & TRank3BB) & emptySquares;
- } while ((from = *pl++) != SQ_NONE);
-
- return mlist;
- }
+ if constexpr (Type == EVASIONS) // Consider only blocking squares
+ {
+ b1 &= target;
+ b2 &= target;
+ }
- template<>
- FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
+ if constexpr (Type == QUIET_CHECKS)
+ {
+ // To make a quiet check, you either make a direct check by pushing a pawn
+ // or push a blocker pawn that is not on the same file as the enemy king.
+ // Discovered check promotion has been already generated amongst the captures.
+ Square ksq = pos.square(Them);
+ Bitboard dcCandidatePawns = pos.blockers_for_king(Them) & ~file_bb(ksq);
+ b1 &= pawn_attacks_bb(Them, ksq) | shift(dcCandidatePawns);
+ b2 &= pawn_attacks_bb(Them, ksq) | shift(dcCandidatePawns);
+ }
- return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq)
- : generate_pawn_moves(p, m, dc, ksq));
- }
+ while (b1)
+ {
+ Square to = pop_lsb(b1);
+ *moveList++ = make_move(to - Up, to);
+ }
- template
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
+ while (b2)
+ {
+ Square to = pop_lsb(b2);
+ *moveList++ = make_move(to - Up - Up, to);
+ }
+ }
- assert(Pt == PAWN);
- assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_EVASION);
+ // Promotions and underpromotions
+ if (pawnsOn7)
+ {
+ Bitboard b1 = shift(pawnsOn7) & enemies;
+ Bitboard b2 = shift(pawnsOn7) & enemies;
+ Bitboard b3 = shift(pawnsOn7) & emptySquares;
- return (us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE)
- : generate_pawn_moves(p, m, t, SQ_NONE));
- }
+ if constexpr (Type == EVASIONS)
+ b3 &= target;
- template
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+ while (b1)
+ moveList = make_promotions(moveList, pop_lsb(b1));
- Bitboard b;
- Square from;
- const Square* pl = pos.piece_list(us, Pt);
+ while (b2)
+ moveList = make_promotions(moveList, pop_lsb(b2));
- if (*pl != SQ_NONE)
- {
- do {
- from = *pl;
- b = pos.attacks_from(from) & target;
- SERIALIZE_MOVES(b);
- } while (*++pl != SQ_NONE);
+ while (b3)
+ moveList = make_promotions(moveList, pop_lsb(b3));
}
- return mlist;
- }
- template<>
- FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+ // Standard and en passant captures
+ if constexpr (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+ {
+ Bitboard b1 = shift(pawnsNotOn7) & enemies;
+ Bitboard b2 = shift(pawnsNotOn7) & enemies;
- Bitboard b;
- Square from = pos.king_square(us);
+ while (b1)
+ {
+ Square to = pop_lsb(b1);
+ *moveList++ = make_move(to - UpRight, to);
+ }
- b = pos.attacks_from(from) & target;
- SERIALIZE_MOVES(b);
- return mlist;
- }
+ while (b2)
+ {
+ Square to = pop_lsb(b2);
+ *moveList++ = make_move(to - UpLeft, to);
+ }
-}
+ if (pos.ep_square() != SQ_NONE)
+ {
+ assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6));
+ // An en passant capture cannot resolve a discovered check
+ if (Type == EVASIONS && (target & (pos.ep_square() + Up)))
+ return moveList;
-/// generate generates all pseudo-legal captures and queen
-/// promotions. Returns a pointer to the end of the move list.
-///
-/// generate generates all pseudo-legal non-captures and
-/// underpromotions. Returns a pointer to the end of the move list.
-///
-/// generate generates all pseudo-legal captures and
-/// non-captures. Returns a pointer to the end of the move list.
-
-template
-MoveStack* generate(const Position& pos, MoveStack* mlist) {
-
- assert(pos.is_ok());
- assert(!pos.in_check());
-
- Color us = pos.side_to_move();
- Bitboard target;
-
- if (Type == MV_CAPTURE || Type == MV_NON_EVASION)
- target = pos.pieces(opposite_color(us));
- else if (Type == MV_NON_CAPTURE)
- target = pos.empty_squares();
- else
- assert(false);
-
- if (Type == MV_NON_EVASION)
- {
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, pos.empty_squares());
- target |= pos.empty_squares();
- }
- else
- mlist = generate_piece_moves(pos, mlist, us, target);
-
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
-
- if (Type != MV_CAPTURE && pos.can_castle(us))
- {
- if (pos.can_castle(us == WHITE ? WHITE_OO : BLACK_OO))
- mlist = generate_castle_moves(pos, mlist, us);
-
- if (pos.can_castle(us == WHITE ? WHITE_OOO : BLACK_OOO))
- mlist = generate_castle_moves(pos, mlist, us);
- }
-
- return mlist;
-}
+ b1 = pawnsNotOn7 & pawn_attacks_bb(Them, pos.ep_square());
-// Explicit template instantiations
-template MoveStack* generate(const Position& pos, MoveStack* mlist);
-template MoveStack* generate(const Position& pos, MoveStack* mlist);
-template MoveStack* generate(const Position& pos, MoveStack* mlist);
+ assert(b1);
+ while (b1)
+ *moveList++ = make(pop_lsb(b1), pos.ep_square());
+ }
+ }
-/// generate_non_capture_checks() 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(const Position& pos, MoveStack* mlist) {
-
- assert(pos.is_ok());
- assert(!pos.in_check());
-
- Bitboard b, dc;
- Square from;
- Color us = pos.side_to_move();
- Square ksq = pos.king_square(opposite_color(us));
-
- assert(pos.piece_on(ksq) == make_piece(opposite_color(us), KING));
-
- // Discovered non-capture checks
- b = dc = pos.discovered_check_candidates(us);
-
- while (b)
- {
- from = pop_1st_bit(&b);
- switch (piece_type(pos.piece_on(from)))
- {
- case PAWN: /* Will be generated togheter with pawns direct checks */ break;
- case KNIGHT: mlist = generate_discovered_checks(pos, mlist, from); break;
- case BISHOP: mlist = generate_discovered_checks(pos, mlist, from); break;
- case ROOK: mlist = generate_discovered_checks(pos, mlist, from); break;
- case KING: mlist = generate_discovered_checks(pos, mlist, from); break;
- default: assert(false); break;
- }
- }
-
- // Direct non-capture checks
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks(pos, mlist, us, dc, ksq);
- return generate_direct_checks(pos, mlist, us, dc, ksq);
+ return moveList;
}
-/// generate_evasions() generates all pseudo-legal check evasions when
-/// the side to move is in check. Returns a pointer to the end of the move list.
-template<>
-MoveStack* generate(const Position& pos, MoveStack* mlist) {
-
- assert(pos.is_ok());
- assert(pos.in_check());
-
- Bitboard b, target;
- Square from, checksq;
- int checkersCnt = 0;
- Color us = pos.side_to_move();
- Square ksq = pos.king_square(us);
- Bitboard checkers = pos.checkers();
- Bitboard sliderAttacks = EmptyBoardBB;
-
- 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 early skip known
- // illegal moves and avoid an useless legality check later.
- b = checkers;
- do
- {
- checkersCnt++;
- checksq = pop_1st_bit(&b);
-
- assert(piece_color(pos.piece_on(checksq)) == opposite_color(us));
-
- switch (piece_type(pos.piece_on(checksq)))
- {
- case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break;
- case ROOK: sliderAttacks |= RookPseudoAttacks[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.
- else
- sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from(checksq);
-
- default:
- break;
- }
- } while (b);
-
- // Generate evasions for king, capture and non capture moves
- b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks;
- from = ksq;
- SERIALIZE_MOVES(b);
-
- // Generate evasions for other pieces only if not double check
- if (checkersCnt > 1)
- return mlist;
-
- // Find squares where a blocking evasion or a capture of the
- // checker piece is possible.
- target = squares_between(checksq, ksq) | checkers;
-
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- mlist = generate_piece_moves(pos, mlist, us, target);
- return generate_piece_moves(pos, mlist, us, target);
-}
+template
+ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
+ static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()");
-/// generate computes a complete list of legal moves in the current position
-
-template<>
-MoveStack* generate(const Position& pos, MoveStack* mlist) {
+ Bitboard bb = pos.pieces(Us, Pt);
- assert(pos.is_ok());
-
- MoveStack *last, *cur = mlist;
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ while (bb)
+ {
+ Square from = pop_lsb(bb);
+ Bitboard b = attacks_bb(from, pos.pieces()) & target;
- last = pos.in_check() ? generate(pos, mlist)
- : generate(pos, mlist);
+ // To check, you either move freely a blocker or make a direct check.
+ if (Checks && (Pt == QUEEN || !(pos.blockers_for_king(~Us) & from)))
+ b &= pos.check_squares(Pt);
- // Remove illegal moves from the list
- while (cur != last)
- if (!pos.pl_move_is_legal(cur->move, pinned))
- cur->move = (--last)->move;
- else
- cur++;
+ while (b)
+ *moveList++ = make_move(from, pop_lsb(b));
+ }
- return last;
+ return moveList;
}
-namespace {
-
- template
- 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
- inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
-
- const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
-
- Bitboard b;
- Square to;
-
- // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black)
- b = move_pawns(pawns) & target & ~TFileABB;
- SERIALIZE_MOVES_D(b, -Delta);
- return mlist;
- }
-
- template
- inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) {
+template
+ExtMove* generate_all(const Position& pos, ExtMove* moveList) {
- const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB);
- const Color Them = (Delta > 0 ? BLACK : WHITE);
+ static_assert(Type != LEGAL, "Unsupported type in generate_all()");
- Bitboard b;
- Square to;
+ constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantiations
+ const Square ksq = pos.square(Us);
+ Bitboard target;
- // Promotions and under-promotions, both captures and non-captures
- b = move_pawns(pawnsOn7) & target;
-
- if (Delta != DELTA_N && Delta != DELTA_S)
- b &= ~TFileABB;
-
- while (b)
+ // Skip generating non-king moves when in double check
+ if (Type != EVASIONS || !more_than_one(pos.checkers()))
{
- to = pop_1st_bit(&b);
-
- if (Type == MV_CAPTURE || Type == MV_EVASION)
- (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN);
-
- if (Type == MV_NON_CAPTURE || Type == MV_EVASION)
- {
- (*mlist++).move = make_promotion_move(to - Delta, to, ROOK);
- (*mlist++).move = make_promotion_move(to - Delta, to, BISHOP);
- (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
- }
-
- // This is the only possible under promotion that can give a check
- // not already included in the queen-promotion.
- if ( Type == MV_CHECK
- && bit_is_set(pos.attacks_from(to), pos.king_square(Them)))
- (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT);
- else (void)pos; // Silence a warning under MSVC
- }
- return mlist;
- }
-
- template
- MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq) {
-
- // Calculate 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 TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
- const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- const Square UP = (Us == WHITE ? DELTA_N : DELTA_S);
- const Square RIGHT_UP = (Us == WHITE ? DELTA_NE : DELTA_SW);
- const Square LEFT_UP = (Us == WHITE ? DELTA_NW : DELTA_SE);
-
- Square to;
- Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares;
- Bitboard pawns = pos.pieces(PAWN, Us);
- Bitboard pawnsOn7 = pawns & TRank7BB;
- Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces(Them));
-
- // Pre-calculate pawn pushes before changing emptySquares definition
- if (Type != MV_CAPTURE)
- {
- emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares());
- pawnPushes = move_pawns(pawns & ~TRank7BB) & emptySquares;
+ target = Type == EVASIONS ? between_bb(ksq, lsb(pos.checkers()))
+ : Type == NON_EVASIONS ? ~pos.pieces(Us)
+ : Type == CAPTURES ? pos.pieces(~Us)
+ : ~pos.pieces(); // QUIETS || QUIET_CHECKS
+
+ moveList = generate_pawn_moves(pos, moveList, target);
+ moveList = generate_moves(pos, moveList, target);
+ moveList = generate_moves(pos, moveList, target);
+ moveList = generate_moves(pos, moveList, target);
+ moveList = generate_moves(pos, moveList, target);
}
- if (Type == MV_EVASION)
+ if (!Checks || pos.blockers_for_king(~Us) & ksq)
{
- emptySquares &= target; // Only blocking squares
- enemyPieces &= target; // Capture only the checker piece
- }
+ Bitboard b = attacks_bb(ksq) & (Type == EVASIONS ? ~pos.pieces(Us) : target);
+ if (Checks)
+ b &= ~attacks_bb(pos.square(~Us));
- // Promotions and underpromotions
- if (pawnsOn7)
- {
- if (Type == MV_CAPTURE)
- emptySquares = pos.empty_squares();
+ while (b)
+ *moveList++ = make_move(ksq, pop_lsb(b));
- pawns &= ~TRank7BB;
- mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions(pos, mlist, pawnsOn7, emptySquares);
+ if ((Type == QUIETS || Type == NON_EVASIONS) && 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(ksq, pos.castling_rook_square(cr));
}
- // Standard captures
- if (Type == MV_CAPTURE || Type == MV_EVASION)
- {
- mlist = generate_pawn_captures(mlist, pawns, enemyPieces);
- mlist = generate_pawn_captures(mlist, pawns, enemyPieces);
- }
+ return moveList;
+}
- // Single and double pawn pushes
- if (Type != MV_CAPTURE)
- {
- b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares);
- b2 = move_pawns(pawnPushes & TRank3BB) & emptySquares;
+} // namespace
- if (Type == MV_CHECK)
- {
- // Consider only pawn moves which give direct checks
- b1 &= pos.attacks_from(ksq, Them);
- b2 &= pos.attacks_from(ksq, Them);
-
- // Add pawn moves which gives 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.
- if (pawns & target) // For CHECK type target is dc bitboard
- {
- dc1 = move_pawns(pawns & target & ~file_bb(ksq)) & emptySquares;
- dc2 = move_pawns(dc1 & TRank3BB) & emptySquares;
-
- b1 |= dc1;
- b2 |= dc2;
- }
- }
- SERIALIZE_MOVES_D(b1, -UP);
- SERIALIZE_MOVES_D(b2, -UP -UP);
- }
- // En passant captures
- if ((Type == MV_CAPTURE || Type == MV_EVASION) && pos.ep_square() != SQ_NONE)
- {
- assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
- assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
+// Generates all pseudo-legal captures plus queen promotions
+// Generates all pseudo-legal non-captures and underpromotions
+// Generates all pseudo-legal check evasions
+// Generates all pseudo-legal captures and non-captures
+// Generates all pseudo-legal non-captures giving check,
+// except castling and promotions
+//
+// Returns a pointer to the end of the move list.
+template
+ExtMove* generate(const Position& pos, ExtMove* moveList) {
- // 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))
- return mlist;
+ static_assert(Type != LEGAL, "Unsupported type in generate()");
+ assert((Type == EVASIONS) == bool(pos.checkers()));
- b1 = pawns & pos.attacks_from(pos.ep_square(), Them);
+ Color us = pos.side_to_move();
- assert(b1 != EmptyBoardBB);
+ return us == WHITE ? generate_all(pos, moveList)
+ : generate_all(pos, moveList);
+}
+
+// Explicit template instantiations
+template ExtMove* generate(const Position&, ExtMove*);
+template ExtMove* generate(const Position&, ExtMove*);
+template ExtMove* generate(const Position&, ExtMove*);
+template ExtMove* generate(const Position&, ExtMove*);
+template ExtMove* generate(const Position&, ExtMove*);
- while (b1)
- {
- to = pop_1st_bit(&b1);
- (*mlist++).move = make_ep_move(to, pos.ep_square());
- }
- }
- return mlist;
- }
-
- template
- MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
-
- CastleRight f = CastleRight((Side == KING_SIDE ? WHITE_OO : WHITE_OOO) << us);
- Color them = opposite_color(us);
-
- // After castling, the rook and king's final positions are exactly the same
- // in Chess960 as they would be in standard chess.
- Square kfrom = pos.king_square(us);
- Square rfrom = pos.castle_rook_square(f);
- Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
- Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
-
- 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 = Min(kfrom, kto); s <= Max(kfrom, kto); s++)
- if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- ||(pos.attackers_to(s) & pos.pieces(them)))
- return mlist;
-
- for (Square s = Min(rfrom, rto); s <= Max(rfrom, rto); s++)
- if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
- 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) & pos.pieces(them))
- return mlist;
- }
- (*mlist++).move = make_castle_move(kfrom, rfrom);
+// generate generates all the legal moves in the given position
- return mlist;
- }
+template<>
+ExtMove* generate(const Position& pos, ExtMove* moveList) {
+
+ Color us = pos.side_to_move();
+ Bitboard pinned = pos.blockers_for_king(us) & pos.pieces(us);
+ Square ksq = pos.square(us);
+ ExtMove* cur = moveList;
+
+ moveList =
+ pos.checkers() ? generate(pos, moveList) : generate(pos, moveList);
+ while (cur != moveList)
+ if (((pinned & from_sq(*cur)) || from_sq(*cur) == ksq || type_of(*cur) == EN_PASSANT)
+ && !pos.legal(*cur))
+ *cur = (--moveList)->move;
+ else
+ ++cur;
+
+ return moveList;
+}
-} // namespace
+} // namespace Stockfish