/*
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) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
/// ordering is at the current node.
/// 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), continuationHistory(ch),
- refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, const LowPlyHistory* lp,
+ const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, const Move* killers, int pl)
+ : pos(p), mainHistory(mh), lowPlyHistory(lp), captureHistory(cph), continuationHistory(ch),
+ ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) {
- assert(d > DEPTH_ZERO);
+ assert(d > 0);
- stage = pos.checkers() ? EVASION_TT : MAIN_TT;
- ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
- stage += (ttMove == MOVE_NONE);
+ stage = (pos.checkers() ? EVASION_TT : MAIN_TT) +
+ !(ttm && pos.pseudo_legal(ttm));
}
/// MovePicker constructor for quiescence search
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs)
- : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), recaptureSquare(rs), depth(d) {
+ : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) {
- assert(d <= DEPTH_ZERO);
+ assert(d <= 0);
- stage = pos.checkers() ? EVASION_TT : QSEARCH_TT;
- ttMove = ttm
- && pos.pseudo_legal(ttm)
- && (depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare) ? ttm : MOVE_NONE;
- stage += (ttMove == MOVE_NONE);
+ stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) +
+ !( ttm
+ && (pos.checkers() || depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare)
+ && pos.pseudo_legal(ttm));
}
/// 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) {
+ : pos(p), captureHistory(cph), ttMove(ttm), threshold(th) {
assert(!pos.checkers());
- stage = PROBCUT_TT;
- ttMove = ttm
- && pos.pseudo_legal(ttm)
- && pos.capture(ttm)
- && pos.see_ge(ttm, threshold) ? ttm : MOVE_NONE;
- stage += (ttMove == MOVE_NONE);
+ stage = PROBCUT_TT + !(ttm && pos.capture(ttm)
+ && pos.pseudo_legal(ttm)
+ && pos.see_ge(ttm, threshold));
}
/// MovePicker::score() assigns a numerical value to each move in a list, used
static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
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)))] / 8;
-
- else if (Type == QUIETS)
- m.value = (*mainHistory)[pos.side_to_move()][from_to(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)];
+ if constexpr (Type == CAPTURES)
+ m.value = int(PieceValue[MG][pos.piece_on(to_sq(m))]) * 6
+ + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))];
+
+ else if constexpr (Type == QUIETS)
+ m.value = (*mainHistory)[pos.side_to_move()][from_to(m)]
+ + 2 * (*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)]
+ + (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)]
+ + (ply < MAX_LPH ? std::min(4, depth / 3) * (*lowPlyHistory)[ply][from_to(m)] : 0);
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)]
- + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+ m.value = (*mainHistory)[pos.side_to_move()][from_to(m)]
+ + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
- (1 << 28);
}
}
if (T == Best)
std::swap(*cur, *std::max_element(cur, endMoves));
- move = *cur++;
+ if (*cur != ttMove && filter())
+ return *cur++;
- if (move != ttMove && filter())
- return move;
+ cur++;
}
- return move = MOVE_NONE;
+ return MOVE_NONE;
}
/// 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
+/// 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) {
case GOOD_CAPTURE:
if (select<Best>([&](){
- return pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)) ?
+ return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ?
// Move losing capture to endBadCaptures to be tried later
- true : (*endBadCaptures++ = move, false); }))
- return move;
+ true : (*endBadCaptures++ = *cur, false); }))
+ return *(cur - 1);
// Prepare the pointers to loop over the refutations array
cur = std::begin(refutations);
--endMoves;
++stage;
- /* fallthrough */
+ [[fallthrough]];
case REFUTATION:
- if (select<Next>([&](){ return move != MOVE_NONE
- && !pos.capture(move)
- && pos.pseudo_legal(move); }))
- return move;
+ if (select<Next>([&](){ return *cur != MOVE_NONE
+ && !pos.capture(*cur)
+ && pos.pseudo_legal(*cur); }))
+ return *(cur - 1);
++stage;
- /* fallthrough */
+ [[fallthrough]];
case QUIET_INIT:
- cur = endBadCaptures;
- endMoves = generate<QUIETS>(pos, cur);
+ if (!skipQuiets)
+ {
+ cur = endBadCaptures;
+ endMoves = generate<QUIETS>(pos, cur);
+
+ score<QUIETS>();
+ partial_insertion_sort(cur, endMoves, -3000 * depth);
+ }
- score<QUIETS>();
- partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY);
++stage;
- /* fallthrough */
+ [[fallthrough]];
case QUIET:
if ( !skipQuiets
- && select<Next>([&](){return move != refutations[0]
- && move != refutations[1]
- && move != refutations[2];}))
- return move;
+ && select<Next>([&](){return *cur != refutations[0].move
+ && *cur != refutations[1].move
+ && *cur != refutations[2].move;}))
+ return *(cur - 1);
// Prepare the pointers to loop over the bad captures
cur = moves;
endMoves = endBadCaptures;
++stage;
- /* fallthrough */
+ [[fallthrough]];
case BAD_CAPTURE:
return select<Next>([](){ return true; });
score<EVASIONS>();
++stage;
- /* fallthrough */
+ [[fallthrough]];
case EVASION:
return select<Best>([](){ return true; });
case PROBCUT:
- return select<Best>([&](){ return pos.see_ge(move, threshold); });
+ return select<Best>([&](){ return pos.see_ge(*cur, threshold); });
case QCAPTURE:
if (select<Best>([&](){ return depth > DEPTH_QS_RECAPTURES
- || to_sq(move) == recaptureSquare; }))
- return move;
+ || to_sq(*cur) == recaptureSquare; }))
+ return *(cur - 1);
// If we did not find any move and we do not try checks, we have finished
if (depth != DEPTH_QS_CHECKS)
return MOVE_NONE;
++stage;
- /* fallthrough */
+ [[fallthrough]];
case QCHECK_INIT:
cur = moves;
endMoves = generate<QUIET_CHECKS>(pos, cur);
++stage;
- /* fallthrough */
+ [[fallthrough]];
case QCHECK:
return select<Next>([](){ return true; });
projects / stockfish / blobdiff