/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, 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
#include "movegen.h"
#include "position.h"
-/// Simple macro to wrap a very common while loop, no fancy, no flexibility,
-/// hardcoded names 'mlist' and 'from'.
-#define SERIALIZE(b) while (b) (mlist++)->move = make_move(from, pop_lsb(&b))
-
-/// 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_lsb(&b); \
- (mlist++)->move = make_move(to - (d), to); }
namespace {
- template<CastlingSide Side, bool Checks, bool Chess960>
- ExtMove* generate_castling(const Position& pos, ExtMove* mlist, Color us, const CheckInfo* ci) {
-
- if (pos.castling_impeded(us, Side) || !pos.can_castle(make_castling_flag(us, Side)))
- return mlist;
-
- // 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(us, Side);
- Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
- Bitboard enemies = pos.pieces(~us);
-
- assert(!pos.checkers());
-
- const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E
- : Side == KING_SIDE ? DELTA_W : DELTA_E;
-
- for (Square s = kto; s != kfrom; s += 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 (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
- return mlist;
-
- Move m = make<CASTLING>(kfrom, rfrom);
-
- if (Checks && !pos.gives_check(m, *ci))
- return mlist;
-
- (mlist++)->move = m;
-
- return mlist;
- }
-
+ template<GenType Type, Direction D>
+ ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) {
- template<GenType Type, Square Delta>
- inline ExtMove* generate_promotions(ExtMove* mlist, Bitboard pawnsOn7,
- Bitboard target, const CheckInfo* ci) {
-
- Bitboard b = shift_bb<Delta>(pawnsOn7) & target;
+ if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+ *moveList++ = make<PROMOTION>(to - D, to, QUEEN);
- while (b)
+ if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
{
- Square to = pop_lsb(&b);
-
- if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
- (mlist++)->move = make<PROMOTION>(to - Delta, to, QUEEN);
-
- if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
- {
- (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 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))
- (mlist++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
- else
- (void)ci; // Silence a warning under MSVC
+ *moveList++ = make<PROMOTION>(to - D, to, ROOK);
+ *moveList++ = make<PROMOTION>(to - D, to, BISHOP);
+ *moveList++ = make<PROMOTION>(to - D, to, KNIGHT);
}
- return mlist;
+ // 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 && (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* mlist,
- Bitboard target, const CheckInfo* ci) {
+ 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 b1, b2, dc1, dc2, emptySquares;
+ Bitboard emptySquares;
Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB;
Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
{
emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
- b1 = shift_bb<Up>(pawnsNotOn7) & emptySquares;
- 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);
+ Square ksq = pos.square<KING>(Them);
+
+ b1 &= pos.attacks_from<PAWN>(ksq, Them);
+ b2 &= pos.attacks_from<PAWN>(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 amongst the captures.
- if (pawnsNotOn7 & ci->dcCandidates)
+ Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7;
+ if (dcCandidateQuiets)
{
- dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
- 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;
}
}
- SERIALIZE_PAWNS(b1, Up);
- SERIALIZE_PAWNS(b2, Up + Up);
+ while (b1)
+ {
+ Square to = pop_lsb(&b1);
+ *moveList++ = make_move(to - Up, to);
+ }
+
+ while (b2)
+ {
+ Square to = pop_lsb(&b2);
+ *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;
- 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);
+ 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, UpRight>(moveList, pop_lsb(&b1), ksq);
+
+ while (b2)
+ moveList = make_promotions<Type, UpLeft >(moveList, pop_lsb(&b2), ksq);
+
+ while (b3)
+ moveList = make_promotions<Type, Up >(moveList, pop_lsb(&b3), ksq);
}
// Standard and en-passant captures
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
{
- b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
- b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
+ Bitboard b1 = shift<UpRight>(pawnsNotOn7) & enemies;
+ Bitboard b2 = shift<UpLeft >(pawnsNotOn7) & enemies;
- SERIALIZE_PAWNS(b1, Right);
- SERIALIZE_PAWNS(b2, Left);
+ while (b1)
+ {
+ Square to = pop_lsb(&b1);
+ *moveList++ = make_move(to - UpRight, to);
+ }
+
+ while (b2)
+ {
+ Square to = pop_lsb(&b2);
+ *moveList++ = make_move(to - UpLeft, to);
+ }
if (pos.ep_square() != SQ_NONE)
{
// 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 == EVASIONS && !(target & (pos.ep_square() - Up)))
- return mlist;
+ return moveList;
b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
assert(b1);
while (b1)
- (mlist++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
+ *moveList++ = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
}
}
- return mlist;
+ return moveList;
}
- template<PieceType Pt, bool Checks> FORCE_INLINE
- ExtMove* generate_moves(const Position& pos, ExtMove* mlist, Color us,
- Bitboard target, const CheckInfo* ci) {
+ template<PieceType Pt, bool Checks>
+ ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
+ Bitboard target) {
assert(Pt != KING && Pt != PAWN);
- const Square* pl = pos.
list<Pt>(us);
+ const Square* pl = pos.
squares<Pt>(us);
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]))
+ && !(PseudoAttacks[Pt][from] & target & pos.check_squares(Pt)))
continue;
- if (unlikely(ci->dcCandidates) && (ci->dcCandidates & from))
+ if (pos.blockers_for_king(~us) & from)
continue;
}
Bitboard b = pos.attacks_from<Pt>(from) & target;
if (Checks)
- b &= ci->checkSq[Pt];
+ b &= pos.check_squares(Pt);
- SERIALIZE(b);
+ while (b)
+ *moveList++ = make_move(from, pop_lsb(&b));
}
- return mlist;
+ return moveList;
}
- template<Color Us, GenType Type> FORCE_INLINE
- ExtMove* generate_all(const Position& pos, ExtMove* mlist, Bitboard target,
- const CheckInfo* ci = NULL) {
+ 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
- mlist = generate_pawn_moves<Us, 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);
+ moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
+ moveList = generate_moves<KNIGHT, Checks>(pos, moveList, Us, target);
+ moveList = generate_moves<BISHOP, Checks>(pos, moveList, Us, target);
+ moveList = generate_moves< ROOK, Checks>(pos, moveList, Us, target);
+ moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target);
if (Type != QUIET_CHECKS && Type != EVASIONS)
{
- Square from = pos.king_square(Us);
- Bitboard b = pos.attacks_from<KING>(from) & target;
- SERIALIZE(b);
- }
+ Square ksq = pos.square<KING>(Us);
+ 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)))
{
- mlist = generate_castling< KING_SIDE, Checks, true>(pos, mlist, Us, ci);
- mlist = generate_castling<QUEEN_SIDE, Checks, true>(pos, mlist, Us, ci);
- }
- else
- {
- mlist = generate_castling< KING_SIDE, Checks, false>(pos, mlist, Us, ci);
- mlist = generate_castling<QUEEN_SIDE, Checks, false>(pos, mlist, Us, ci);
+ 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));
}
}
- return mlist;
+ return moveList;
}
-
} // namespace
-/// generate<CAPTURES> generates all pseudo-legal captures and queen
-/// promotions. 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<QUIETS> generates all pseudo-legal non-captures and
-/// underpromotions. Returns a pointer to the end of the move list.
-///
-/// 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* mlist) {
+ExtMove* generate(const Position& pos, ExtMove* moveList) {
assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
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;
+ 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, mlist, target)
- : generate_all<BLACK, Type>(pos, mlist, target);
+ return us == WHITE ? generate_all<WHITE, Type>(pos, moveList, target)
+ : generate_all<BLACK, Type>(pos, moveList, target);
}
// Explicit template instantiations
/// 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.
template<>
-ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* mlist) {
+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);
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][ci.ksq];
+ b &= ~PseudoAttacks[QUEEN][pos.square<KING>(~us)];
- SERIALIZE(b);
+ while (b)
+ *moveList++ = make_move(from, pop_lsb(&b));
}
- return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, mlist, ~pos.pieces(), &ci)
- : generate_all<BLACK, QUIET_CHECKS>(pos, mlist, ~pos.pieces(), &ci);
+ return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces())
+ : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces());
}
/// 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<>
-ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* mlist) {
+ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
assert(pos.checkers());
- int checkersCnt = 0;
Color us = pos.side_to_move();
- Square ksq = pos.king_square(us), from = ksq /* For SERIALIZE */, checksq;
+ Square ksq = pos.square<KING>(us);
Bitboard sliderAttacks = 0;
- Bitboard b = pos.checkers();
-
- assert(pos.checkers());
+ Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN);
// Find all the squares attacked by slider checkers. We will remove them from
// the king evasions in order to skip known illegal moves, which avoids any
// useless legality checks later on.
- do
+ while (sliders)
{
- ++checkersCnt;
- checksq = pop_lsb(&b);
-
- assert(color_of(pos.piece_on(checksq)) == ~us);
-
- if (type_of(pos.piece_on(checksq)) > KNIGHT) // A slider
- sliderAttacks |= LineBB[checksq][ksq] ^ checksq;
-
- } while (b);
+ Square checksq = pop_lsb(&sliders);
+ sliderAttacks |= LineBB[checksq][ksq] ^ checksq;
+ }
// Generate evasions for king, capture and non capture moves
- b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
- SERIALIZE(b);
+ Bitboard b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
+ while (b)
+ *moveList++ = make_move(ksq, pop_lsb(&b));
- if (checkersCnt > 1)
- return mlist; // Double check, only a king move can save the day
+ 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, mlist, target)
- : generate_all<BLACK, EVASIONS>(pos, mlist, target);
+ return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList, target)
+ : generate_all<BLACK, EVASIONS>(pos, moveList, target);
}
/// generate<LEGAL> generates all the legal moves in the given position
template<>
-ExtMove* generate<LEGAL>(const Position& pos, ExtMove* mlist) {
-
- ExtMove *end, *cur = mlist;
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- Square ksq = pos.king_square(pos.side_to_move());
-
- end = pos.checkers() ? generate<EVASIONS>(pos, mlist)
- : generate<NON_EVASIONS>(pos, mlist);
- while (cur != end)
- if ( (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
- && !pos.legal(cur->move, pinned))
- cur->move = (--end)->move;
+ExtMove* generate<LEGAL>(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<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) == ksq || type_of(*cur) == ENPASSANT)
+ && !pos.legal(*cur))
+ *cur = (--moveList)->move;
else
++cur;
- return end;
+ return moveList;
}
projects / stockfish / blobdiff