along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <algorithm>
#include <cassert>
-#include "movegen.h"
#include "movepick.h"
+#include "thread.h"
namespace {
enum Sequencer {
- MAIN_SEARCH, TT_MOVE_S1, CAPTURES_S1, KILLERS_S1, QUIETS_1_S1,
- QUIETS_2_S1, BAD_CAPTURES_S1, STOP_S1,
- EVASIONS, TT_MOVE_S2, EVASIONS_S2, STOP_S2,
- CAPTURES_AND_CHECKS, TT_MOVE_S3, CAPTURES_S3, QUIET_CHECKS_S3, STOP_S3,
- CAPTURES, TT_MOVE_S4, CAPTURES_S4, STOP_S4,
- PROBCUT, TT_MOVE_S5, CAPTURES_S5, STOP_S5,
- RECAPTURES, CAPTURES_S6, STOP_S6
+ 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,
+ QSEARCH_1, CAPTURES_S4,
+ PROBCUT, CAPTURES_S5,
+ RECAPTURE, CAPTURES_S6,
+ STOP
};
+ // Our insertion sort, guaranteed to be stable, as is needed
+ void insertion_sort(MoveStack* begin, MoveStack* end)
+ {
+ MoveStack tmp, *p, *q;
+
+ for (p = begin + 1; p < end; ++p)
+ {
+ tmp = *p;
+ for (q = p; q != begin && *(q-1) < tmp; --q)
+ *q = *(q-1);
+ *q = tmp;
+ }
+ }
+
// 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& move) { return move.score > 0; }
+ inline bool has_positive_score(const MoveStack& ms) { return ms.score > 0; }
- // Picks and moves to the front the best move in the range [firstMove, lastMove),
+ // 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* firstMove, MoveStack* lastMove)
+ inline MoveStack* pick_best(MoveStack* begin, MoveStack* end)
{
- std::swap(*firstMove, *std::max_element(firstMove, lastMove));
- return firstMove;
+ std::swap(*begin, *std::max_element(begin, end));
+ return begin;
}
}
/// move ordering is at the current node.
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
- Search::Stack* ss, Value beta) : pos(p), H(h), depth(d) {
+ Search::Stack* s, Value beta) : pos(p), Hist(h), depth(d) {
assert(d > DEPTH_ZERO);
captureThreshold = 0;
- curMove = lastMove = 0;
- badCaptures = moves + MAX_MOVES;
+ cur = end = moves;
+ endBadCaptures = moves + MAX_MOVES - 1;
+ ss = s;
- if (p.in_check())
- phase = EVASIONS;
+ if (p.checkers())
+ phase = EVASION;
else
{
+ phase = MAIN_SEARCH;
+
killers[0].move = ss->killers[0];
killers[1].move = ss->killers[1];
// Consider sligtly negative captures as good if at low depth and far from beta
- if (ss && ss->eval < beta - PawnValueMidgame && d < 3 * ONE_PLY)
- captureThreshold = -PawnValueMidgame;
+ 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->eval > beta)
- captureThreshold = beta - ss->eval;
-
- phase = MAIN_SEARCH;
+ else if (ss && ss->staticEval > beta)
+ captureThreshold = beta - ss->staticEval;
}
ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
- phase += (ttMove == MOVE_NONE);
+ end += (ttMove != MOVE_NONE);
}
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
- Square sq) : pos(p), H(h), curMove(0), lastMove(0) {
+ Square sq) : pos(p), Hist(h), cur(moves), end(moves) {
assert(d <= DEPTH_ZERO);
- if (p.in_check())
- phase = EVASIONS;
+ if (p.checkers())
+ phase = EVASION;
else if (d > DEPTH_QS_NO_CHECKS)
- phase = CAPTURES_AND_CHECKS;
+ phase = QSEARCH_0;
else if (d > DEPTH_QS_RECAPTURES)
{
- phase = CAPTURES;
+ phase = 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 = RECAPTURES - 1;
+ phase = RECAPTURE;
recaptureSquare = sq;
ttm = MOVE_NONE;
}
ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
- phase += (ttMove == MOVE_NONE);
+ end += (ttMove != MOVE_NONE);
}
-MovePicker::MovePicker(const Position& p, Move ttm, const History& h,
- PieceType pt) : pos(p), H(h), curMove(0), lastMove(0) {
+MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt)
+ : pos(p), Hist(h), cur(moves), end(moves) {
- assert(!pos.in_check());
+ assert(!pos.checkers());
phase = PROBCUT;
// In ProbCut we generate only captures better than parent's captured piece
- captureThreshold = PieceValueMidgame[pt];
+ captureThreshold = PieceValue[MG][pt];
+ ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
- if (ttm && (!pos.is_capture(ttm) || pos.see(ttm) <= captureThreshold))
- ttm = MOVE_NONE;
+ if (ttMove && (!pos.is_capture(ttMove) || pos.see(ttMove) <= captureThreshold))
+ ttMove = MOVE_NONE;
- ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
- phase += (ttMove == MOVE_NONE);
+ end += (ttMove != MOVE_NONE);
}
-/// MovePicker::score_captures(), MovePicker::score_noncaptures() and
-/// MovePicker::score_evasions() assign a numerical move ordering score
-/// to each move in a move list. The moves with highest scores will be
-/// picked first by next_move().
-
-void MovePicker::score_captures() {
+/// score() assign a numerical move ordering score to each move in a move list.
+/// The moves with highest scores will be picked first.
+template<>
+void MovePicker::score<CAPTURES>() {
// Winning and equal captures in the main search are ordered by MVV/LVA.
// Suprisingly, this appears to perform slightly better than SEE based
// move ordering. The reason is probably that in a position with a winning
// some SEE calls in case we get a cutoff (idea from Pablo Vazquez).
Move m;
- for (MoveStack* cur = moves; cur != lastMove; cur++)
+ for (MoveStack* it = moves; it != end; ++it)
{
- m = cur->move;
- cur->score = PieceValueMidgame[pos.piece_on(to_sq(m))]
- - type_of(pos.piece_moved(m));
+ m = it->move;
+ it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
+ - type_of(pos.piece_moved(m));
+
+ if (type_of(m) == PROMOTION)
+ it->score += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
- if (is_promotion(m))
- cur->score += PieceValueMidgame[promotion_piece_type(m)];
+ else if (type_of(m) == ENPASSANT)
+ it->score += PieceValue[MG][PAWN];
}
}
-void MovePicker::score_noncaptures() {
+template<>
+void MovePicker::score<QUIETS>() {
Move m;
- Square from;
- for (MoveStack* cur = moves; cur != lastMove; cur++)
+ for (MoveStack* it = moves; it != end; ++it)
{
- m = cur->move;
- from = from_sq(m);
- cur->score = H.value(pos.piece_on(from), to_sq(m));
+ m = it->move;
+ it->score = Hist[pos.piece_moved(m)][to_sq(m)];
}
}
-void MovePicker::score_evasions() {
+template<>
+void MovePicker::score<EVASIONS>() {
// Try good captures ordered by MVV/LVA, then non-captures if destination square
// is not under attack, ordered by history value, then bad-captures and quiet
// moves with a negative SEE. This last group is ordered by the SEE score.
Move m;
int seeScore;
- if (lastMove < moves + 2)
- return;
-
- for (MoveStack* cur = moves; cur != lastMove; cur++)
+ for (MoveStack* it = moves; it != end; ++it)
{
- m = cur->move;
+ m = it->move;
if ((seeScore = pos.see_sign(m)) < 0)
- cur->score = seeScore - History::MaxValue; // Be sure we are at the bottom
+ it->score = seeScore - History::Max; // At the bottom
+
else if (pos.is_capture(m))
- cur->score = PieceValueMidgame[pos.piece_on(to_sq(m))]
- - type_of(pos.piece_moved(m)) + History::MaxValue;
+ it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
+ - type_of(pos.piece_moved(m)) + History::Max;
else
- cur->score = H.value(pos.piece_moved(m), to_sq(m));
+ it->score = Hist[pos.piece_moved(m)][to_sq(m)];
}
}
-/// MovePicker::next_phase() generates, scores and sorts the next bunch of moves,
-/// when there are no more moves to try for the current phase.
+/// generate_next() generates, scores and sorts the next bunch of moves, when
+/// there are no more moves to try for the current phase.
-void MovePicker::next_phase() {
+void MovePicker::generate_next() {
- curMove = moves;
+ cur = moves;
switch (++phase) {
- case TT_MOVE_S1: case TT_MOVE_S2: case TT_MOVE_S3: case TT_MOVE_S4: case TT_MOVE_S5:
- lastMove = curMove + 1;
- return;
-
case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
- lastMove = generate<MV_CAPTURE>(pos, moves);
- score_captures();
+ end = generate<CAPTURES>(pos, moves);
+ score<CAPTURES>();
return;
case KILLERS_S1:
- curMove = killers;
- lastMove = curMove + 2;
+ cur = killers;
+ end = cur + 2;
return;
case QUIETS_1_S1:
- lastQuiet = lastMove = generate<MV_QUIET>(pos, moves);
- score_noncaptures();
- lastMove = std::partition(curMove, lastMove, has_positive_score);
- sort<MoveStack>(curMove, lastMove);
+ endQuiets = end = generate<QUIETS>(pos, moves);
+ score<QUIETS>();
+ end = std::partition(cur, end, has_positive_score);
+ insertion_sort(cur, end);
return;
case QUIETS_2_S1:
- curMove = lastMove;
- lastMove = lastQuiet;
+ cur = end;
+ end = endQuiets;
if (depth >= 3 * ONE_PLY)
- sort<MoveStack>(curMove, lastMove);
+ insertion_sort(cur, end);
return;
case BAD_CAPTURES_S1:
- // Bad captures SEE value is already calculated so just pick them in order
- // to get SEE move ordering.
- curMove = badCaptures;
- lastMove = moves + MAX_MOVES;
+ // Just pick them in reverse order to get MVV/LVA ordering
+ cur = moves + MAX_MOVES - 1;
+ end = endBadCaptures;
return;
case EVASIONS_S2:
- lastMove = generate<MV_EVASION>(pos, moves);
- score_evasions();
+ end = generate<EVASIONS>(pos, moves);
+ if (end > moves + 1)
+ score<EVASIONS>();
return;
case QUIET_CHECKS_S3:
- lastMove = generate<MV_QUIET_CHECK>(pos, moves);
+ end = generate<QUIET_CHECKS>(pos, moves);
return;
- case STOP_S1: case STOP_S2: case STOP_S3: case STOP_S4: case STOP_S5: case STOP_S6:
- lastMove = curMove + 1; // Avoid another next_phase() call
+ case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE:
+ phase = STOP;
+ case STOP:
+ end = cur + 1; // Avoid another next_phase() call
return;
default:
}
-/// MovePicker::next_move() is the most important method of the MovePicker class.
-/// It returns 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 to return the tt move if has already been
-/// searched previously. Note that this function is not thread safe so should be
-/// lock protected by caller when accessed through a shared MovePicker object.
-
-Move MovePicker::next_move() {
+/// 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
+/// 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<>
+Move MovePicker::next_move<false>() {
Move move;
while (true)
{
- while (curMove == lastMove)
- next_phase();
+ while (cur == end)
+ generate_next();
switch (phase) {
- case TT_MOVE_S1: case TT_MOVE_S2: case TT_MOVE_S3: case TT_MOVE_S4: case TT_MOVE_S5:
- curMove++;
+ case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
+ cur++;
return ttMove;
case CAPTURES_S1:
- move = pick_best(curMove++, lastMove)->move;
+ move = pick_best(cur++, end)->move;
if (move != ttMove)
{
assert(captureThreshold <= 0); // Otherwise we cannot use see_sign()
- int seeScore = pos.see_sign(move);
- if (seeScore >= captureThreshold)
+ if (pos.see_sign(move) >= captureThreshold)
return move;
// Losing capture, move it to the tail of the array
- (--badCaptures)->move = move;
- badCaptures->score = seeScore;
+ (endBadCaptures--)->move = move;
}
break;
case KILLERS_S1:
- move = (curMove++)->move;
- if ( move != MOVE_NONE
- && pos.is_pseudo_legal(move)
- && move != ttMove
+ move = (cur++)->move;
+ if ( move != MOVE_NONE
+ && pos.is_pseudo_legal(move)
+ && move != ttMove
&& !pos.is_capture(move))
return move;
break;
- case QUIETS_1_S1:
- case QUIETS_2_S1:
- move = (curMove++)->move;
+ case QUIETS_1_S1: case QUIETS_2_S1:
+ move = (cur++)->move;
if ( move != ttMove
&& move != killers[0].move
&& move != killers[1].move)
break;
case BAD_CAPTURES_S1:
- move = pick_best(curMove++, lastMove)->move;
- return move;
+ return (cur--)->move;
- case EVASIONS_S2:
- case CAPTURES_S3:
- case CAPTURES_S4:
- move = pick_best(curMove++, lastMove)->move;
+ case EVASIONS_S2: case CAPTURES_S3: case CAPTURES_S4:
+ move = pick_best(cur++, end)->move;
if (move != ttMove)
return move;
break;
case CAPTURES_S5:
- move = pick_best(curMove++, lastMove)->move;
+ move = pick_best(cur++, end)->move;
if (move != ttMove && pos.see(move) > captureThreshold)
return move;
break;
case CAPTURES_S6:
- move = pick_best(curMove++, lastMove)->move;
+ move = pick_best(cur++, end)->move;
if (to_sq(move) == recaptureSquare)
return move;
break;
case QUIET_CHECKS_S3:
- move = (curMove++)->move;
+ move = (cur++)->move;
if (move != ttMove)
return move;
break;
- case STOP_S1: case STOP_S2: case STOP_S3: case STOP_S4: case STOP_S5: case STOP_S6:
+ case STOP:
return MOVE_NONE;
default:
}
}
}
+
+
+/// Version of next_move() to use at split point nodes where the move is grabbed
+/// from the split point's shared MovePicker object. This function is not thread
+/// safe so must be lock protected by the caller.
+template<>
+Move MovePicker::next_move<true>() { return ss->sp->movePicker->next_move<false>(); }
projects / stockfish / blobdiff