/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, 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 facny, 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>
- MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
+ 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.castle_impeded(us, Side) || !pos.can_castle(make_castle_right(us, Side)))
- return mlist;
+ 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.castle_rook_square(us, Side);
- Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ 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 int K = Chess960 ? kto > kfrom ? -1 : 1
- : Side == KING_SIDE ? -1 : 1;
+ const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E
+ : KingSide ? DELTA_W : DELTA_E;
- for (Square s = kto; s != kfrom; s += (Square)K)
+ for (Square s = kto; s != kfrom; s += K)
if (pos.attackers_to(s) & enemies)
- return mlist;
+ 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 && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
- return mlist;
-
- (*mlist++).move = make<CASTLE>(kfrom, rfrom);
-
- if (Checks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
- mlist--;
+ if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
+ return moveList;
- return mlist;
- }
+ Move m = make<CASTLING>(kfrom, rfrom);
+ if (Checks && !pos.gives_check(m, *ci))
+ return moveList;
- template<Square Delta>
- inline Bitboard move_pawns(Bitboard p) {
+ (moveList++)->move = m;
- 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;
+ return moveList;
}
template<GenType Type, Square Delta>
- inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7,
- Bitboard target, const CheckInfo* ci) {
+ inline ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) {
- Bitboard b = move_pawns<Delta>(pawnsOn7) & target;
+ if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+ (moveList++)->move = make<PROMOTION>(to - Delta, 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 one that can give a direct check 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++)->move = make<PROMOTION>(to - Delta, to, ROOK);
+ (moveList++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
+ (moveList++)->move = make<PROMOTION>(to - Delta, 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 && (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>
- MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist,
- Bitboard target, const CheckInfo* ci) {
+ 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 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);
+ 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);
- 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 = move_pawns<UP>(pawnsNotOn7) & emptySquares;
- b2 = move_pawns<UP>(b1 & TRank3BB) & emptySquares;
+ Bitboard b1 = shift_bb<Up>(pawnsNotOn7) & emptySquares;
+ Bitboard b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;
if (Type == EVASIONS) // Consider only blocking squares
{
// 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.
+ // promotion has been already generated amongst the captures.
if (pawnsNotOn7 & ci->dcCandidates)
{
- dc1 = move_pawns<UP>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
- dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
+ Bitboard dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
+ Bitboard dc2 = shift_bb<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++)->move = make_move(to - Up, to);
+ }
+
+ while (b2)
+ {
+ Square to = pop_lsb(&b2);
+ (moveList++)->move = make_move(to - Up - Up, to);
+ }
}
// Promotions and underpromotions
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_bb<Right>(pawnsOn7) & enemies;
+ Bitboard b2 = shift_bb<Left >(pawnsOn7) & enemies;
+ Bitboard b3 = shift_bb<Up >(pawnsOn7) & emptySquares;
+
+ while (b1)
+ moveList = make_promotions<Type, Right>(moveList, pop_lsb(&b1), ci);
+
+ while (b2)
+ moveList = make_promotions<Type, Left >(moveList, pop_lsb(&b2), ci);
+
+ while (b3)
+ moveList = make_promotions<Type, Up >(moveList, pop_lsb(&b3), ci);
}
// Standard and en-passant captures
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
{
- b1 = move_pawns<RIGHT>(pawnsNotOn7) & enemies;
- b2 = move_pawns<LEFT >(pawnsNotOn7) & enemies;
+ Bitboard b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
+ Bitboard b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
+
+ while (b1)
+ {
+ Square to = pop_lsb(&b1);
+ (moveList++)->move = make_move(to - Right, to);
+ }
- SERIALIZE_PAWNS(b1, RIGHT);
- SERIALIZE_PAWNS(b2, LEFT);
+ while (b2)
+ {
+ Square to = pop_lsb(&b2);
+ (moveList++)->move = make_move(to - Left, to);
+ }
if (pos.ep_square() != SQ_NONE)
{
// 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 == EVASIONS && !(target & (pos.ep_square() - UP)))
- return mlist;
+ if (Type == EVASIONS && !(target & (pos.ep_square() - Up)))
+ 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++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
}
}
- return mlist;
+ return moveList;
}
template<PieceType Pt, bool Checks> FORCE_INLINE
- MoveStack* generate_moves(const Position& pos, MoveStack* mlist, Color us,
- Bitboard target, const CheckInfo* ci) {
+ ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
+ Bitboard target, const CheckInfo* ci) {
assert(Pt != KING && Pt != PAWN);
- const Square* pl = pos.piece_list(us, Pt);
+ const Square* pl = pos.list<Pt>(us);
for (Square from = *pl; from != SQ_NONE; from = *++pl)
{
if (Checks)
b &= ci->checkSq[Pt];
- SERIALIZE(b);
+ while (b)
+ (moveList++)->move = make_move(from, pop_lsb(&b));
}
- return mlist;
+ return moveList;
}
- template<GenType Type> FORCE_INLINE
- MoveStack* generate_all(const Position& pos, MoveStack* mlist, Color us,
- Bitboard target, const CheckInfo* ci = NULL) {
+ template<Color Us, GenType Type> FORCE_INLINE
+ ExtMove* generate_all(const Position& pos, ExtMove* moveList, 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);
+ 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);
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.king_square(Us);
+ Bitboard b = pos.attacks_from<KING>(ksq) & target;
+ while (b)
+ (moveList++)->move = make_move(ksq, pop_lsb(&b));
}
- if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(us))
+ 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);
+ 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
{
- mlist = generate_castle<KING_SIDE, Checks, false>(pos, mlist, us);
- mlist = generate_castle<QUEEN_SIDE, Checks, false>(pos, mlist, us);
+ 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);
}
}
- return mlist;
+ return moveList;
}
-
} // namespace
/// non-captures. Returns a pointer to the end of the move list.
template<GenType Type>
-MoveStack* generate(const Position& pos, MoveStack* 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 generate_all<Type>(pos, mlist, us, target);
+ return us == WHITE ? generate_all<WHITE, Type>(pos, moveList, target)
+ : generate_all<BLACK, Type>(pos, moveList, target);
}
// Explicit template instantiations
-template MoveStack* generate<CAPTURES>(const Position&, MoveStack*);
-template MoveStack* generate<QUIETS>(const Position&, MoveStack*);
-template MoveStack* generate<NON_EVASIONS>(const Position&, MoveStack*);
+template ExtMove* generate<CAPTURES>(const Position&, ExtMove*);
+template ExtMove* generate<QUIETS>(const Position&, ExtMove*);
+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.
template<>
-MoveStack* generate<QUIET_CHECKS>(const Position& pos, MoveStack* 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;
PieceType pt = type_of(pos.piece_on(from));
if (pt == PAWN)
- continue; // Will be generated togheter with direct checks
+ continue; // Will be generated together with direct checks
Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
if (pt == KING)
b &= ~PseudoAttacks[QUEEN][ci.ksq];
- SERIALIZE(b);
+ while (b)
+ (moveList++)->move = make_move(from, pop_lsb(&b));
}
- return generate_all<QUIET_CHECKS>(pos, mlist, pos.side_to_move(), ~pos.pieces(), &ci);
+ return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci)
+ : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci);
}
/// 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<EVASIONS>(const Position& pos, MoveStack* mlist) {
+ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
assert(pos.checkers());
- Square from, checksq;
- int checkersCnt = 0;
Color us = pos.side_to_move();
Square ksq = pos.king_square(us);
Bitboard sliderAttacks = 0;
- Bitboard b = pos.checkers();
-
- assert(pos.checkers());
+ Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN);
- // 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.
- do
+ // 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.
+ while (sliders)
{
- checkersCnt++;
- checksq = pop_lsb(&b);
-
- assert(color_of(pos.piece_on(checksq)) == ~us);
-
- switch (type_of(pos.piece_on(checksq)))
- {
- case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break;
- case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break;
- case QUEEN:
- // 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 (between_bb(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 |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from<ROOK>(checksq);
-
- default:
- break;
- }
- } 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;
- from = ksq;
- SERIALIZE(b);
+ Bitboard b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
+ while (b)
+ (moveList++)->move = 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
- Bitboard target = between_bb(checksq, ksq) | pos.checkers();
+ Square checksq = lsb(pos.checkers());
+ Bitboard target = between_bb(checksq, ksq) | checksq;
- return generate_all<EVASIONS>(pos, mlist, us, 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<>
-MoveStack* generate<LEGAL>(const Position& pos, MoveStack* mlist) {
+ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {
- MoveStack *end, *cur = mlist;
- Bitboard pinned = pos.pinned_pieces();
+ Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
Square ksq = pos.king_square(pos.side_to_move());
+ ExtMove* cur = moveList;
- end = pos.checkers() ? generate<EVASIONS>(pos, mlist)
- : generate<NON_EVASIONS>(pos, mlist);
- while (cur != end)
+ 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.pl_move_is_legal(cur->move, pinned))
- cur->move = (--end)->move;
+ && !pos.legal(cur->move, pinned))
+ cur->move = (--moveList)->move;
else
- cur++;
+ ++cur;
- return end;
+ return moveList;
}
projects / stockfish / blobdiff