along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <algorithm>
#include <cassert>
#include "movegen.h"
const uint8_t QsearchWithoutChecksTable[] = { PH_TT_MOVE, PH_QCAPTURES, PH_STOP };
const uint8_t QsearchRecapturesTable[] = { PH_TT_MOVE, PH_QRECAPTURES, PH_STOP };
const uint8_t ProbCutTable[] = { PH_TT_MOVE, PH_GOOD_PROBCUT, PH_STOP };
+
+ // 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; }
+
+ // Picks and pushes to the front the best move in range [firstMove, lastMove),
+ // 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)
+ {
+ std::swap(*firstMove, *std::max_element(firstMove, lastMove));
+ return firstMove;
+ }
}
/// Constructors for the MovePicker class. As arguments we pass information
case PH_NONCAPTURES_1:
lastNonCapture = lastMove = generate<MV_NON_CAPTURE>(pos, moves);
score_noncaptures();
- sort_moves(moves, lastNonCapture, &lastMove);
+ lastMove = std::partition(curMove, lastMove, has_positive_score);
+ sort<MoveStack>(curMove, lastMove);
return;
case PH_NONCAPTURES_2:
curMove = lastMove;
lastMove = lastNonCapture;
if (depth >= 3 * ONE_PLY)
- insertion_sort<MoveStack>(curMove, lastMove);
+ sort<MoveStack>(curMove, lastMove);
return;
case PH_BAD_CAPTURES:
{
m = cur->move;
cur->score = piece_value_midgame(pos.piece_on(move_to(m)))
- - type_of_piece(pos.piece_on(move_from(m)));
+ - piece_type(pos.piece_on(move_from(m)));
if (move_is_promotion(m))
- cur->score += QueenValueMidgame;
+ cur->score += piece_value_midgame(Piece(promotion_piece_type(m)));
}
}
cur->score = seeScore - History::MaxValue; // Be sure we are at the bottom
else if (pos.move_is_capture(m))
cur->score = piece_value_midgame(pos.piece_on(move_to(m)))
- - type_of_piece(pos.piece_on(move_from(m))) + History::MaxValue;
+ - piece_type(pos.piece_on(move_from(m))) + History::MaxValue;
else
cur->score = H.value(pos.piece_on(move_from(m)), move_to(m));
}
break;
case PH_GOOD_CAPTURES:
- move = pick_best(curMove++, lastMove).move;
+ move = pick_best(curMove++, lastMove)->move;
if (move != ttMove)
{
assert(captureThreshold <= 0); // Otherwise we must use see instead of see_sign
if (seeValue >= captureThreshold)
return move;
- // Losing capture, move it to the tail of the array, note
- // that move has now been already checked for pseudo legality.
+ // Losing capture, move it to the tail of the array
(--badCaptures)->move = move;
badCaptures->score = seeValue;
}
break;
case PH_GOOD_PROBCUT:
- move = pick_best(curMove++, lastMove).move;
+ move = pick_best(curMove++, lastMove)->move;
if ( move != ttMove
&& pos.see(move) > captureThreshold)
return move;
break;
case PH_BAD_CAPTURES:
- move = pick_best(curMove++, lastMove).move;
+ move = pick_best(curMove++, lastMove)->move;
return move;
case PH_EVASIONS:
case PH_QCAPTURES:
- move = pick_best(curMove++, lastMove).move;
+ move = pick_best(curMove++, lastMove)->move;
if (move != ttMove)
return move;
break;