Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, 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
QSEARCH_TT, QCAPTURE_INIT, QCAPTURE, QCHECK_INIT, QCHECK
};
- // Helper filter used with select_move()
- const auto Any = [](){ return true; };
-
// partial_insertion_sort() sorts moves in descending order up to and including
// a given limit. The order of moves smaller than the limit is left unspecified.
void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) {
/// 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)
- : pos(p), mainHistory(mh), captureHistory(cph), contHistory(ch),
- refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d){
+ : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch),
+ refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
assert(d > DEPTH_ZERO);
/// MovePicker constructor for quiescence search
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
- const CapturePieceToHistory* cph, Square rs)
- : pos(p), mainHistory(mh), captureHistory(cph), recaptureSquare(rs), depth(d) {
+ const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs)
+ : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), recaptureSquare(rs), 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)))] / 8;
else if (Type == QUIETS)
m.value = (*mainHistory)[pos.side_to_move()][from_to(m)]
- + (*contHistory[0])[pos.moved_piece(m)][to_sq(m)]
- + (*contHistory[1])[pos.moved_piece(m)][to_sq(m)]
- + (*contHistory[3])[pos.moved_piece(m)][to_sq(m)];
+ + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+ + (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
+ + (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)];
else // Type == EVASIONS
{
m.value = PieceValue[MG][pos.piece_on(to_sq(m))]
- Value(type_of(pos.moved_piece(m)));
else
- m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - (1 << 28);
+ m.value = (*mainHistory)[pos.side_to_move()][from_to(m)]
+ + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+ - (1 << 28);
}
}
-/// MovePicker::select_move() returns the next move satisfying a predicate function.
+/// MovePicker::select() returns the next move satisfying a predicate function.
/// It never returns the TT move.
-template<PickType T, typename Pred>
-Move MovePicker::select_move(Pred filter) {
+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++;
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);
+ cur = std::begin(refutations);
+ endMoves = std::end(refutations);
// If the countermove is the same as a killer, skip it
if ( refutations[0].move == refutations[2].move
/* fallthrough */
case REFUTATION:
- if (select_move<NEXT>([&](){ return move != MOVE_NONE
- && !pos.capture(move)
- && pos.pseudo_legal(move); }))
+ 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;
// Prepare the pointers to loop over the bad captures
- cur = moves, endMoves = endBadCaptures;
+ cur = moves;
+ endMoves = endBadCaptures;
+
++stage;
/* fallthrough */
case BAD_CAPTURE:
- return select_move<NEXT>(Any);
+ return select<Next>([](){ return true; });
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>([](){ return true; });
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>([](){ return true; });
}
assert(false);
projects / stockfish / blobdiff