/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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"
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& ms) { return ms.score > 0; }
/// 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 History& h,
- Search::Stack* s, Value beta) : pos(p), H(h), depth(d) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, const Refutations& r,
+ Search::Stack* s, Value beta) : pos(p), Hist(h), depth(d) {
assert(d > DEPTH_ZERO);
endBadCaptures = moves + MAX_MOVES - 1;
ss = s;
- if (p.in_check())
+ if (p.checkers())
phase = EVASION;
else
killers[0].move = ss->killers[0];
killers[1].move = ss->killers[1];
+ Square prevSq = to_sq((ss-1)->currentMove);
+ killers[2].move = r[pos.piece_on(prevSq)][prevSq];
// Consider sligtly negative captures as good if at low depth and far from beta
- if (ss && ss->eval < beta - PawnValueMg && d < 3 * ONE_PLY)
+ 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;
+ else if (ss && ss->staticEval > beta)
+ captureThreshold = beta - ss->staticEval;
}
ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
}
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
- Square sq) : pos(p), H(h), cur(moves), end(moves) {
+ Square sq) : pos(p), Hist(h), cur(moves), end(moves) {
assert(d <= DEPTH_ZERO);
- if (p.in_check())
+ if (p.checkers())
phase = EVASION;
else if (d > DEPTH_QS_NO_CHECKS)
}
MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt)
- : pos(p), H(h), cur(moves), end(moves) {
+ : pos(p), Hist(h), cur(moves), end(moves) {
- assert(!pos.in_check());
+ assert(!pos.checkers());
phase = PROBCUT;
}
-/// 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
- type_of(pos.piece_moved(m));
if (type_of(m) == PROMOTION)
- it->score += PieceValue[MG][promotion_type(m)];
+ it->score += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
+
+ else if (type_of(m) == ENPASSANT)
+ it->score += PieceValue[MG][PAWN];
}
}
-void MovePicker::score_noncaptures() {
+template<>
+void MovePicker::score<QUIETS>() {
Move m;
for (MoveStack* it = moves; it != end; ++it)
{
m = it->move;
- it->score = H.value(pos.piece_moved(m), to_sq(m));
+ 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 (end < moves + 2)
- return;
-
for (MoveStack* it = moves; it != end; ++it)
{
m = it->move;
if ((seeScore = pos.see_sign(m)) < 0)
- it->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))
it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
- - type_of(pos.piece_moved(m)) + History::MaxValue;
+ - type_of(pos.piece_moved(m)) + History::Max;
else
- it->score = H.value(pos.piece_moved(m), to_sq(m));
+ it->score = Hist[pos.piece_moved(m)][to_sq(m)];
}
}
-/// MovePicker::generate_next() 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::generate_next() {
case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
end = generate<CAPTURES>(pos, moves);
- score_captures();
+ score<CAPTURES>();
return;
case KILLERS_S1:
cur = killers;
- end = cur + 2;
+ end = cur + 3;
return;
case QUIETS_1_S1:
endQuiets = end = generate<QUIETS>(pos, moves);
- score_noncaptures();
+ score<QUIETS>();
end = std::partition(cur, end, has_positive_score);
- sort<MoveStack>(cur, end);
+ insertion_sort(cur, end);
return;
case QUIETS_2_S1:
cur = end;
end = endQuiets;
if (depth >= 3 * ONE_PLY)
- sort<MoveStack>(cur, end);
+ insertion_sort(cur, end);
return;
case BAD_CAPTURES_S1:
case EVASIONS_S2:
end = generate<EVASIONS>(pos, moves);
- score_evasions();
+ if (end > moves + 1)
+ score<EVASIONS>();
return;
case QUIET_CHECKS_S3:
}
-/// 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.
+/// 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 = (cur++)->move;
if ( move != ttMove
&& move != killers[0].move
- && move != killers[1].move)
+ && move != killers[1].move
+ && move != killers[2].move)
return move;
break;
/// 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 should be lock protected by the caller.
+/// safe so must be lock protected by the caller.
template<>
-Move MovePicker::next_move<true>() { return ss->sp->mp->next_move<false>(); }
+Move MovePicker::next_move<true>() { return ss->splitPoint->movePicker->next_move<false>(); }
projects / stockfish / blobdiff