}
-/// Position::move_is_legal() takes a position and a (not necessarily pseudo-legal)
-/// move and tests whether the move is legal. This version is not very fast and
-/// should be used only in non time-critical paths.
+/// Position::move_is_pl_slow() takes a position and a move and tests whether
+/// the move is pseudo legal. This version is not very fast and should be used
+/// only in non time-critical paths.
-bool Position::move_is_legal(const Move m) const {
+bool Position::move_is_pl_slow(const Move m) const {
MoveStack mlist[MAX_MOVES];
- MoveStack *cur, *last = generate<MV_PSEUDO_LEGAL>(*this, mlist);
+ MoveStack *cur, *last;
- for (cur = mlist; cur != last; cur++)
+ last = in_check() ? generate<MV_EVASION>(*this, mlist)
+ : generate<MV_NON_EVASION>(*this, mlist);
+
+ for (cur = mlist; cur != last; cur++)
if (cur->move == m)
- return pl_move_is_legal(m, pinned_pieces(sideToMove));
+ return true;
return false;
}
-/// Fast version of Position::move_is_legal() that takes a position a move and
-/// a bitboard of pinned pieces as input, and tests whether the move is legal.
+/// Fast version of Position::move_is_pl() that takes a position a move and a
+/// bitboard of pinned pieces as input, and tests whether the move is pseudo legal.
-bool Position::move_is_legal(const Move m, Bitboard pinned) const {
+bool Position::move_is_pl(const Move m) const {
assert(is_ok());
- assert(pinned == pinned_pieces(sideToMove));
Color us = sideToMove;
Color them = opposite_color(sideToMove);
// Use a slower but simpler function for uncommon cases
if (move_is_special(m))
- return move_is_legal(m);
+ return move_is_pl_slow(m);
// Is not a promotion, so promotion piece must be empty
if (move_promotion_piece(m) - 2 != PIECE_TYPE_NONE)
}
}
- // The move is pseudo-legal, check if it is also legal
- return pl_move_is_legal(m, pinned);
+ return true;
}
/// Position::is_draw() tests whether the position is drawn by material,
/// repetition, or the 50 moves rule. It does not detect stalemates, this
/// must be done by the search.
-
+template<bool SkipRepetition>
bool Position::is_draw() const {
// Draw by material?
return true;
// Draw by repetition?
- for (int i = 4, e = Min(Min(st->gamePly, st->rule50), st->pliesFromNull); i <= e; i += 2)
- if (history[st->gamePly - i] == st->key)
- return true;
+ if (!SkipRepetition)
+ for (int i = 4, e = Min(Min(st->gamePly, st->rule50), st->pliesFromNull); i <= e; i += 2)
+ if (history[st->gamePly - i] == st->key)
+ return true;
return false;
}
+// Explicit template instantiations
+template bool Position::is_draw<false>() const;
+template bool Position::is_draw<true>() const;
+
/// Position::is_mate() returns true or false depending on whether the
/// side to move is checkmated.