STOP
};
- // Our insertion sort, guaranteed to be stable, as is needed
+ // Our insertion sort, which is guaranteed (and also needed) to be stable
void insertion_sort(ExtMove* begin, ExtMove* end)
{
ExtMove tmp, *p, *q;
// ones so to sort separately the two sets, and with the second sort delayed.
inline bool has_positive_score(const ExtMove& ms) { return ms.score > 0; }
- // Picks and moves to the front the best move in the range [begin, end),
- // it is faster than sorting all the moves in advance when moves are few, as
- // normally are the possible captures.
+ // Picks the best move in the range (begin, end) and moves it to the front.
+ // It's faster than sorting all the moves in advance when there are few
+ // moves e.g. possible captures.
inline ExtMove* pick_best(ExtMove* begin, ExtMove* end)
{
std::swap(*begin, *std::max_element(begin, end));
else
stage = MAIN_SEARCH;
- ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
+ ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
end += (ttMove != MOVE_NONE);
}
{
stage = QSEARCH_1;
- // Skip TT move if is not a capture or a promotion, this avoids qsearch
+ // Skip TT move if is not a capture or a promotion. This avoids qsearch
// tree explosion due to a possible perpetual check or similar rare cases
// when TT table is full.
- if (ttm && !pos.is_capture_or_promotion(ttm))
+ if (ttm && !pos.capture_or_promotion(ttm))
ttm = MOVE_NONE;
}
else
ttm = MOVE_NONE;
}
- ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
+ ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
end += (ttMove != MOVE_NONE);
}
stage = PROBCUT;
- // In ProbCut we generate only captures better than parent's captured piece
+ // In ProbCut we generate only captures that are better than the parent's
+ // captured piece.
captureThreshold = PieceValue[MG][pt];
- ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
+ ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
- if (ttMove && (!pos.is_capture(ttMove) || pos.see(ttMove) <= captureThreshold))
+ if (ttMove && (!pos.capture(ttMove) || pos.see(ttMove) <= captureThreshold))
ttMove = MOVE_NONE;
end += (ttMove != MOVE_NONE);
// where it is possible to recapture with the hanging piece). Exchanging
// big pieces before capturing a hanging piece probably helps to reduce
// the subtree size.
- // In main search we want to push captures with negative SEE values to
- // badCaptures[] array, but instead of doing it now we delay till when
- // the move has been picked up in pick_move_from_list(), this way we save
- // some SEE calls in case we get a cutoff (idea from Pablo Vazquez).
+ // In main search we want to push captures with negative SEE values to the
+ // badCaptures[] array, but instead of doing it now we delay until the move
+ // has been picked up in pick_move_from_list(). This way we save some SEE
+ // calls in case we get a cutoff.
Move m;
for (ExtMove* it = moves; it != end; ++it)
{
m = it->move;
it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
- - type_of(pos.piece_moved(m));
+ - type_of(pos.moved_piece(m));
if (type_of(m) == PROMOTION)
it->score += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
for (ExtMove* it = moves; it != end; ++it)
{
m = it->move;
- it->score = history[pos.piece_moved(m)][to_sq(m)];
+ it->score = history[pos.moved_piece(m)][to_sq(m)];
}
}
if ((seeScore = pos.see_sign(m)) < 0)
it->score = seeScore - HistoryStats::Max; // At the bottom
- else if (pos.is_capture(m))
+ else if (pos.capture(m))
it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
- - type_of(pos.piece_moved(m)) + HistoryStats::Max;
+ - type_of(pos.moved_piece(m)) + HistoryStats::Max;
else
- it->score = history[pos.piece_moved(m)][to_sq(m)];
+ it->score = history[pos.moved_piece(m)][to_sq(m)];
}
}
/// next_move() is the most important method of the MovePicker class. It returns
-/// a new pseudo legal move every time is called, until there are no more moves
+/// a new pseudo legal move every time it is called, until there are no more moves
/// left. It picks the move with the biggest score from a list of generated moves
/// taking care not returning the ttMove if has already been searched previously.
template<>
switch (stage) {
case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
- cur++;
+ ++cur;
return ttMove;
case CAPTURES_S1:
case KILLERS_S1:
move = (cur++)->move;
if ( move != MOVE_NONE
- && pos.is_pseudo_legal(move)
+ && pos.pseudo_legal(move)
&& move != ttMove
- && !pos.is_capture(move))
+ && !pos.capture(move))
return move;
break;