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,
/// 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, Move* 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;
+ cur = end = moves = pos.this_thread()->get_moves_array();
endBadCaptures = moves + MAX_MOVES - 1;
countermoves = cm;
ss = s;
if (p.checkers())
- phase = EVASION;
+ stage = EVASION;
else
- {
- phase = MAIN_SEARCH;
-
- // Consider sligtly negative captures as good if at low depth and far from beta
- if (ss->staticEval < beta - PawnValueMg && d < 3 * ONE_PLY)
- captureThreshold = -PawnValueMg;
-
- // Consider negative captures as good if still enough to reach beta
- else if (ss->staticEval > beta)
- captureThreshold = beta - ss->staticEval;
- }
+ stage = MAIN_SEARCH;
ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
end += (ttMove != MOVE_NONE);
}
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
- Square sq) : pos(p), history(h), cur(moves), end(moves) {
+ Square sq) : pos(p), history(h) {
assert(d <= DEPTH_ZERO);
+ cur = end = moves = pos.this_thread()->get_moves_array();
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
}
else
{
- phase = RECAPTURE;
+ stage = RECAPTURE;
recaptureSquare = sq;
ttm = MOVE_NONE;
}
}
MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, PieceType pt)
- : pos(p), history(h), cur(moves), end(moves) {
+ : pos(p), history(h) {
assert(!pos.checkers());
- phase = PROBCUT;
+ cur = end = moves = pos.this_thread()->get_moves_array();
+ stage = PROBCUT;
// In ProbCut we generate only captures better than parent's captured piece
captureThreshold = PieceValue[MG][pt];
end += (ttMove != MOVE_NONE);
}
+MovePicker::~MovePicker() { pos.this_thread()->free_moves_array(); }
/// score() assign a numerical move ordering score to each move in a move list.
/// The moves with highest scores will be picked first.
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);
killers[2].move = killers[3].move = MOVE_NONE;
// Be sure countermoves are different from killers
- for (int i = 0; i < 2; i++)
+ for (int i = 0; i < 2; ++i)
if (countermoves[i] != cur->move && countermoves[i] != (cur+1)->move)
(end++)->move = countermoves[i];
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++;
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