namespace {
- enum Sequencer {
+ enum Stages {
MAIN_SEARCH, CAPTURES_S1, KILLERS_S1, QUIETS_1_S1, QUIETS_2_S1, BAD_CAPTURES_S1,
EVASION, EVASIONS_S2,
QSEARCH_0, CAPTURES_S3, QUIET_CHECKS_S3,
};
// Our insertion sort, guaranteed to be stable, as is needed
- void insertion_sort(MoveStack* begin, MoveStack* end)
+ void insertion_sort(ExtMove* begin, ExtMove* end)
{
- MoveStack tmp, *p, *q;
+ ExtMove tmp, *p, *q;
for (p = begin + 1; p < end; ++p)
{
// Unary predicate used by std::partition to split positive scores from remaining
// ones so to sort separately the two sets, and with the second sort delayed.
- inline bool has_positive_score(const MoveStack& ms) { return ms.score > 0; }
+ 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.
- inline MoveStack* pick_best(MoveStack* begin, MoveStack* end)
+ inline ExtMove* pick_best(ExtMove* begin, ExtMove* end)
{
std::swap(*begin, *std::max_element(begin, end));
return begin;
/// search captures, promotions and some checks) and about how important good
/// move ordering is at the current node.
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h, const CountermovesStats& cm,
- Search::Stack* s, Value beta) : pos(p), history(h), depth(d) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
+ Move* cm, Search::Stack* s) : pos(p), history(h), depth(d) {
assert(d > DEPTH_ZERO);
- captureThreshold = 0;
cur = end = moves;
endBadCaptures = moves + MAX_MOVES - 1;
+ countermoves = cm;
ss = s;
if (p.checkers())
- phase = EVASION;
+ stage = EVASION;
else
- {
- phase = MAIN_SEARCH;
-
- killers[0].move = ss->killers[0];
- killers[1].move = ss->killers[1];
- Square prevSq = to_sq((ss-1)->currentMove);
- killers[2].move = cm[pos.piece_on(prevSq)][prevSq];
+ stage = MAIN_SEARCH;
- // Consider sligtly negative captures as good if at low depth and far from beta
- if (ss && ss->staticEval < beta - PawnValueMg && d < 3 * ONE_PLY)
- captureThreshold = -PawnValueMg;
-
- // Consider negative captures as good if still enough to reach beta
- else if (ss && ss->staticEval > beta)
- captureThreshold = beta - ss->staticEval;
- }
-
- ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
+ ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
end += (ttMove != MOVE_NONE);
}
assert(d <= DEPTH_ZERO);
if (p.checkers())
- phase = EVASION;
+ stage = EVASION;
else if (d > DEPTH_QS_NO_CHECKS)
- phase = QSEARCH_0;
+ stage = QSEARCH_0;
else if (d > DEPTH_QS_RECAPTURES)
{
- phase = QSEARCH_1;
+ stage = QSEARCH_1;
// 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
{
- phase = RECAPTURE;
+ stage = RECAPTURE;
recaptureSquare = sq;
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);
}
assert(!pos.checkers());
- phase = PROBCUT;
+ stage = PROBCUT;
// In ProbCut we generate only captures better than 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);
}
+/// quiet_moves() returns a pointer to the beginning of moves array. It
+/// is used to access already tried quiet moves when updating history.
+
+const ExtMove* MovePicker::quiet_moves() const {
+ return stage == KILLERS_S1 ? killers
+ : stage == QUIETS_1_S1 || stage == QUIETS_2_S1 ? moves : NULL;
+}
+
+
/// score() assign a numerical move ordering score to each move in a move list.
/// The moves with highest scores will be picked first.
template<>
// some SEE calls in case we get a cutoff (idea from Pablo Vazquez).
Move m;
- for (MoveStack* it = moves; it != end; ++it)
+ 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];
Move m;
- for (MoveStack* it = moves; it != end; ++it)
+ 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)];
}
}
Move m;
int seeScore;
- for (MoveStack* it = moves; it != end; ++it)
+ for (ExtMove* it = moves; it != end; ++it)
{
m = it->move;
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)];
}
}
cur = moves;
- switch (++phase) {
+ switch (++stage) {
case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
end = generate<CAPTURES>(pos, moves);
case KILLERS_S1:
cur = killers;
- end = cur + 3 - (killers[2].move == killers[0].move || killers[2].move == killers[1].move);
+ end = cur + 2;
+
+ killers[0].move = ss->killers[0];
+ killers[1].move = ss->killers[1];
+ killers[2].move = killers[3].move = MOVE_NONE;
+
+ // Be sure countermoves are different from killers
+ for (int i = 0; i < 2; ++i)
+ if (countermoves[i] != cur->move && countermoves[i] != (cur+1)->move)
+ (end++)->move = countermoves[i];
+
+ if (countermoves[1] && countermoves[1] == countermoves[0]) // Due to SMP races
+ killers[3].move = MOVE_NONE;
+
return;
case QUIETS_1_S1:
return;
case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE:
- phase = STOP;
+ stage = STOP;
case STOP:
end = cur + 1; // Avoid another next_phase() call
return;
while (cur == end)
generate_next();
- switch (phase) {
+ switch (stage) {
case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
- cur++;
+ ++cur;
return ttMove;
case CAPTURES_S1:
move = pick_best(cur++, end)->move;
if (move != ttMove)
{
- assert(captureThreshold <= 0); // Otherwise we cannot use see_sign()
-
- if (pos.see_sign(move) >= captureThreshold)
+ if (pos.see_sign(move) >= 0)
return move;
// Losing capture, move it to the tail of the array
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;
if ( move != ttMove
&& move != killers[0].move
&& move != killers[1].move
- && move != killers[2].move)
+ && move != killers[2].move
+ && move != killers[3].move)
return move;
break;
projects / stockfish / blobdiff