namespace {
enum Stages {
- MAIN_TT, CAPTURE_INIT, GOOD_CAPTURE, KILLER0, KILLER1, COUNTERMOVE, QUIET_INIT, QUIET, BAD_CAPTURE,
+ MAIN_TT, CAPTURE_INIT, GOOD_CAPTURE, REFUTATION, QUIET_INIT, QUIET, BAD_CAPTURE,
EVASION_TT, EVASION_INIT, EVASION,
PROBCUT_TT, PROBCUT_INIT, PROBCUT,
QSEARCH_TT, QCAPTURE_INIT, QCAPTURE, QCHECK_INIT, QCHECK
};
- // Helper filter used with select_move()
+ // Helper filter used with select()
const auto Any = [](){ return true; };
// partial_insertion_sort() sorts moves in descending order up to and including
/// MovePicker constructor for the main search
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
- const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers_p)
+ const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers)
: pos(p), mainHistory(mh), captureHistory(cph), contHistory(ch),
- refutations{killers_p[0], killers_p[1], cm}, depth(d){
+ refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
assert(d > DEPTH_ZERO);
stage += (ttMove == MOVE_NONE);
}
-/// MovePicker constructor for ProbCut: we generate captures with SEE higher
+/// MovePicker constructor for ProbCut: we generate captures with SEE greater
/// than or equal to the given threshold.
MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph)
: pos(p), captureHistory(cph), threshold(th) {
for (auto& m : *this)
if (Type == CAPTURES)
m.value = PieceValue[MG][pos.piece_on(to_sq(m))]
- + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))];
+ + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))] / 16;
else if (Type == QUIETS)
m.value = (*mainHistory)[pos.side_to_move()][from_to(m)]
}
}
-/// MovePicker::select_move() returns the next move satisfying a predicate function
-template<PickType T, typename Pred>
-Move MovePicker::select_move(Pred filter) {
+/// MovePicker::select() returns the next move satisfying a predicate function.
+/// It never returns the TT move.
+template<MovePicker::PickType T, typename Pred>
+Move MovePicker::select(Pred filter) {
while (cur < endMoves)
{
- if (T == BEST_SCORE)
+ if (T == Best)
std::swap(*cur, *std::max_element(cur, endMoves));
move = *cur++;
}
/// 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 highest score from a list of generated moves.
+/// returns a new pseudo legal move every time it is called until there are no more
+/// moves left, picking the move with the highest score from a list of generated moves.
Move MovePicker::next_move(bool skipQuiets) {
top:
case CAPTURE_INIT:
case PROBCUT_INIT:
case QCAPTURE_INIT:
- endBadCaptures = cur = moves;
+ cur = endBadCaptures = moves;
endMoves = generate<CAPTURES>(pos, cur);
+
score<CAPTURES>();
++stage;
goto top;
case GOOD_CAPTURE:
- if (select_move<BEST_SCORE>([&](){ return pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)) ?
- // Move losing capture to endBadCaptures to be tried later
- true : (*endBadCaptures++ = move, false); }))
+ if (select<Best>([&](){
+ return pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)) ?
+ // Move losing capture to endBadCaptures to be tried later
+ true : (*endBadCaptures++ = move, false); }))
return move;
+ // Prepare the pointers to loop over the refutations array
+ cur = std::begin(refutations);
+ endMoves = std::end(refutations);
+
// If the countermove is the same as a killer, skip it
- if ( refutations[0] == refutations[2]
- || refutations[1] == refutations[2])
- refutations[2] = MOVE_NONE;
+ if ( refutations[0].move == refutations[2].move
+ || refutations[1].move == refutations[2].move)
+ --endMoves;
+
++stage;
/* fallthrough */
- case KILLER0:
- case KILLER1:
- case COUNTERMOVE:
- while (stage <= COUNTERMOVE)
- {
- move = refutations[ stage++ - KILLER0];
- if ( move != MOVE_NONE
- && move != ttMove
- && pos.pseudo_legal(move)
- && !pos.capture(move))
- return move;
- }
+ case REFUTATION:
+ if (select<Next>([&](){ return move != MOVE_NONE
+ && !pos.capture(move)
+ && pos.pseudo_legal(move); }))
+ return move;
+ ++stage;
/* fallthrough */
case QUIET_INIT:
cur = endBadCaptures;
endMoves = generate<QUIETS>(pos, cur);
+
score<QUIETS>();
partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY);
++stage;
case QUIET:
if ( !skipQuiets
- && select_move<NEXT>([&](){return move != refutations[0]
- && move != refutations[1]
- && move != refutations[2];}))
+ && select<Next>([&](){return move != refutations[0]
+ && move != refutations[1]
+ && move != refutations[2];}))
return move;
- // Point to beginning and end of bad captures
- cur = moves, endMoves = endBadCaptures;
+ // Prepare the pointers to loop over the bad captures
+ cur = moves;
+ endMoves = endBadCaptures;
+
++stage;
/* fallthrough */
case BAD_CAPTURE:
- return select_move<NEXT>(Any);
+ return select<Next>(Any);
case EVASION_INIT:
cur = moves;
endMoves = generate<EVASIONS>(pos, cur);
+
score<EVASIONS>();
++stage;
/* fallthrough */
case EVASION:
- return select_move<BEST_SCORE>(Any);
+ return select<Best>(Any);
case PROBCUT:
- return select_move<BEST_SCORE>([&](){ return pos.see_ge(move, threshold); });
+ return select<Best>([&](){ return pos.see_ge(move, threshold); });
case QCAPTURE:
- if (select_move<BEST_SCORE>([&](){ return depth > DEPTH_QS_RECAPTURES
- || to_sq(move) == recaptureSquare; }))
+ if (select<Best>([&](){ return depth > DEPTH_QS_RECAPTURES
+ || to_sq(move) == recaptureSquare; }))
return move;
// If we did not find any move and we do not try checks, we have finished
case QCHECK_INIT:
cur = moves;
endMoves = generate<QUIET_CHECKS>(pos, cur);
+
++stage;
/* fallthrough */
case QCHECK:
- return select_move<NEXT>(Any);
+ return select<Next>(Any);
}
assert(false);
projects / stockfish / blobdiff