/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 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
EVASION, EVASIONS_S2,
QSEARCH_0, CAPTURES_S3, QUIET_CHECKS_S3,
QSEARCH_1, CAPTURES_S4,
- MULTICUT, CAPTURES_S5,
+ PROBCUT, CAPTURES_S5,
RECAPTURE, CAPTURES_S6,
STOP
};
}
}
- // Unary predicate used by std::partition to split positive scores from remaining
+ // Unary predicate used by std::partition to split positive values from remaining
// ones so as to sort the two sets separately, with the second sort delayed.
- inline bool has_positive_score(const ExtMove& ms) { return ms.score > 0; }
+ inline bool has_positive_value(const ExtMove& move) { return move.value > VALUE_ZERO; }
// Picks the best move in the range (begin, end) and moves it to the front.
// It's faster than sorting all the moves in advance when there are few
std::swap(*begin, *std::max_element(begin, end));
return begin;
}
-}
+} // namespace
/// Constructors of the MovePicker class. As arguments we pass information
followupmoves = fm;
ss = s;
- if (p.checkers())
+ if (pos.checkers())
stage = EVASION;
else
}
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
- Square sq) : pos(p), history(h), cur(moves), end(moves) {
+ Square s) : pos(p), history(h), cur(moves), end(moves) {
assert(d <= DEPTH_ZERO);
- if (p.checkers())
+ if (pos.checkers())
stage = EVASION;
else if (d > DEPTH_QS_NO_CHECKS)
stage = QSEARCH_0;
else if (d > DEPTH_QS_RECAPTURES)
- {
stage = QSEARCH_1;
- // Skip TT move if is not a capture or a promotion. This avoids qsearch
- // tree explosion due to a possible perpetual check or similar rare cases
- // when TT table is full.
- if (ttm && !pos.capture_or_promotion(ttm))
- ttm = MOVE_NONE;
- }
else
{
stage = RECAPTURE;
- recaptureSquare = sq;
+ recaptureSquare = s;
ttm = MOVE_NONE;
}
assert(!pos.checkers());
- stage = MULTICUT;
+ stage = PROBCUT;
- // In MultiCut we generate only captures that are better than the parent's
+ // In ProbCut we generate only captures that are better than the parent's
// captured piece.
captureThreshold = PieceValue[MG][pt];
ttMove = (ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE);
}
-/// score() assign a numerical move ordering score to each move in a move list.
-/// The moves with highest scores will be picked first.
+/// score() assign a numerical value to each move in a move list. The moves with
+/// highest values will be picked first.
template<>
void MovePicker::score<CAPTURES>() {
// Winning and equal captures in the main search are ordered by MVV/LVA.
for (ExtMove* it = moves; it != end; ++it)
{
m = it->move;
- it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
- - type_of(pos.moved_piece(m));
+ it->value = PieceValue[MG][pos.piece_on(to_sq(m))]
+ - Value(type_of(pos.moved_piece(m)));
- if (type_of(m) == PROMOTION)
- it->score += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
+ if (type_of(m) == ENPASSANT)
+ it->value += PieceValue[MG][PAWN];
- else if (type_of(m) == ENPASSANT)
- it->score += PieceValue[MG][PAWN];
+ else if (type_of(m) == PROMOTION)
+ it->value += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
}
}
for (ExtMove* it = moves; it != end; ++it)
{
m = it->move;
- it->score = history[pos.moved_piece(m)][to_sq(m)];
+ it->value = history[pos.moved_piece(m)][to_sq(m)];
}
}
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.
+ // moves with a negative SEE. This last group is ordered by the SEE value.
Move m;
- int seeScore;
+ Value see;
for (ExtMove* it = moves; it != end; ++it)
{
m = it->move;
- if ((seeScore = pos.see_sign(m)) < 0)
- it->score = seeScore - HistoryStats::Max; // At the bottom
+ if ((see = pos.see_sign(m)) < VALUE_ZERO)
+ it->value = see - HistoryStats::Max; // At the bottom
else if (pos.capture(m))
- it->score = PieceValue[MG][pos.piece_on(to_sq(m))]
- - type_of(pos.moved_piece(m)) + HistoryStats::Max;
+ it->value = PieceValue[MG][pos.piece_on(to_sq(m))]
+ - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max;
else
- it->score = history[pos.moved_piece(m)][to_sq(m)];
+ it->value = history[pos.moved_piece(m)][to_sq(m)];
}
}
case QUIETS_1_S1:
endQuiets = end = generate<QUIETS>(pos, moves);
score<QUIETS>();
- end = std::partition(cur, end, has_positive_score);
+ end = std::partition(cur, end, has_positive_value);
insertion_sort(cur, end);
return;
end = generate<QUIET_CHECKS>(pos, moves);
return;
- case EVASION: case QSEARCH_0: case QSEARCH_1: case MULTICUT: case RECAPTURE:
+ case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE:
stage = STOP;
+ /* Fall through */
+
case STOP:
end = cur + 1; // Avoid another next_phase() call
return;
/// 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
+/// left. It picks the move with the biggest value from a list of generated moves
/// taking care not to return the ttMove if it has already been searched.
template<>
Move MovePicker::next_move<false>() {
switch (stage) {
- case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case MULTICUT:
+ case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
++cur;
return ttMove;
move = pick_best(cur++, end)->move;
if (move != ttMove)
{
- if (pos.see_sign(move) >= 0)
+ if (pos.see_sign(move) >= VALUE_ZERO)
return move;
// Losing capture, move it to the tail of the array
case KILLERS_S1:
move = (cur++)->move;
if ( move != MOVE_NONE
- && pos.pseudo_legal(move)
&& move != ttMove
+ && pos.pseudo_legal(move)
&& !pos.capture(move))
return move;
break;
projects / stockfish / blobdiff