/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2014 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,
+/// 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))
+#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); }
+ (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) {
+ ExtMove* generate_castling(const Position& pos, ExtMove* mlist, Color us) {
- if (pos.castle_impeded(us, Side) || !pos.can_castle(make_castle_right(us, Side)))
+ 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.castle_rook_square(us, Side);
+ 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);
// 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))
+ if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
return mlist;
- (*mlist++).move = make<CASTLE>(kfrom, rfrom);
+ (mlist++)->move = make<CASTLING>(kfrom, rfrom);
- if (Checks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
- mlist--;
+ if (Checks && !pos.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, const CheckInfo* ci) {
+ inline ExtMove* generate_promotions(ExtMove* mlist, Bitboard pawnsOn7,
+ Bitboard target, const CheckInfo* ci) {
Bitboard b = shift_bb<Delta>(pawnsOn7) & target;
Square to = pop_lsb(&b);
if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
- (*mlist++).move = make<PROMOTION>(to - Delta, to, QUEEN);
+ (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);
+ (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.
+ // 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);
+ (mlist++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
else
(void)ci; // Silence a warning under MSVC
}
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* mlist,
+ Bitboard target, const CheckInfo* ci) {
// Compute our parametrized parameters at compile time, named according to
// the point of view of white side.
// 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 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
assert(b1);
while (b1)
- (*mlist++).move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
+ (mlist++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
}
}
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* mlist, Color us,
+ Bitboard target, const CheckInfo* ci) {
assert(Pt != KING && Pt != PAWN);
&& !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
continue;
- if (ci->dcCandidates && (ci->dcCandidates & from))
+ if (unlikely(ci->dcCandidates) && (ci->dcCandidates & from))
continue;
}
}
- 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* mlist, 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);
+ 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);
if (Type != QUIET_CHECKS && Type != EVASIONS)
{
- Square from = pos.king_square(us);
+ 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 (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);
+ mlist = generate_castling< KING_SIDE, Checks, true>(pos, mlist, Us);
+ mlist = generate_castling<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);
+ mlist = generate_castling< KING_SIDE, Checks, false>(pos, mlist, Us);
+ mlist = generate_castling<QUEEN_SIDE, Checks, false>(pos, mlist, Us);
}
}
/// 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* mlist) {
assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
assert(!pos.checkers());
: 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, mlist, target)
+ : generate_all<BLACK, Type>(pos, mlist, 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* mlist) {
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();
SERIALIZE(b);
}
- return generate_all<QUIET_CHECKS>(pos, mlist, pos.side_to_move(), ~pos.pieces(), &ci);
+ return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, mlist, ~pos.pieces(), &ci)
+ : generate_all<BLACK, QUIET_CHECKS>(pos, mlist, ~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* mlist) {
assert(pos.checkers());
- Square from, checksq;
int checkersCnt = 0;
Color us = pos.side_to_move();
- Square ksq = pos.king_square(us);
+ Square ksq = pos.king_square(us), from = ksq /* For SERIALIZE */, checksq;
Bitboard sliderAttacks = 0;
Bitboard b = pos.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.
+ // 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
{
- checkersCnt++;
+ ++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;
- }
+ if (type_of(pos.piece_on(checksq)) > KNIGHT) // A slider
+ sliderAttacks |= LineBB[checksq][ksq] ^ checksq;
+
} while (b);
// Generate evasions for king, capture and non capture moves
b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
- from = ksq;
SERIALIZE(b);
if (checkersCnt > 1)
return mlist; // 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();
+ Bitboard target = between_bb(checksq, ksq) | checksq;
- return generate_all<EVASIONS>(pos, mlist, us, target);
+ return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, mlist, target)
+ : generate_all<BLACK, EVASIONS>(pos, mlist, 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* mlist) {
- MoveStack *end, *cur = mlist;
- Bitboard pinned = pos.pinned_pieces();
+ 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.pl_move_is_legal(cur->move, pinned))
+ && !pos.legal(cur->move, pinned))
cur->move = (--end)->move;
else
- cur++;
+ ++cur;
return end;
}