/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+ Copyright (C) 2004-2022 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
#include "movepick.h"
+namespace Stockfish {
+
namespace {
enum Stages {
/// 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 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) {
-
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
+ const CapturePieceToHistory* cph,
+ const PieceToHistory** ch,
+ Move cm,
+ const Move* killers)
+ : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch),
+ ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d)
+{
assert(d > 0);
stage = (pos.checkers() ? EVASION_TT : MAIN_TT) +
/// 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), ttMove(ttm), recaptureSquare(rs), depth(d) {
-
+ const CapturePieceToHistory* cph,
+ const PieceToHistory** ch,
+ Square rs)
+ : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d)
+{
assert(d <= 0);
stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) +
/// 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), ttMove(ttm), threshold(th) {
-
+MovePicker::MovePicker(const Position& p, Move ttm, Value th, Depth d, const CapturePieceToHistory* cph)
+ : pos(p), captureHistory(cph), ttMove(ttm), threshold(th), depth(d)
+{
assert(!pos.checkers());
stage = PROBCUT_TT + !(ttm && pos.capture(ttm)
&& pos.see_ge(ttm, threshold));
}
+//squares threatened by pawn attacks
+template <Color Us>
+Bitboard threatsByPawn (const Position& pos)
+{
+ return pawn_attacks_bb<Us>(pos.pieces(Us, PAWN));
+}
+
+//squares threatened by minor attacks
+template <Color Us>
+Bitboard threatsByMinor (const Position& pos)
+{
+ Bitboard our = pos.pieces(Us, KNIGHT, BISHOP);
+ Bitboard threats = 0;
+ while (our)
+ {
+ Square s = pop_lsb(our);
+ if (type_of(pos.piece_on(s)) == KNIGHT)
+ threats |= attacks_bb<KNIGHT>(s, pos.pieces());
+ else
+ threats |= attacks_bb<BISHOP>(s, pos.pieces());
+ }
+ return threats;
+}
+
+//squares threatened by rook attacks
+template <Color Us>
+Bitboard threatsByRook (const Position& pos)
+{
+ Bitboard our = pos.pieces(Us, ROOK);
+ Bitboard threats = 0;
+ while (our)
+ {
+ Square s = pop_lsb(our);
+ threats |= attacks_bb<ROOK>(s, pos.pieces());
+ }
+ return threats;
+}
+
/// MovePicker::score() assigns a numerical value to each move in a list, used
/// for sorting. Captures are ordered by Most Valuable Victim (MVV), preferring
/// captures with a good history. Quiets moves are ordered using the histories.
static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type");
+ Bitboard threatened, threatenedByPawn, threatenedByMinor, threatenedByRook;
+ if constexpr (Type == QUIETS)
+ {
+ // squares threatened by pawns
+ threatenedByPawn = pos.side_to_move() == WHITE ? threatsByPawn<BLACK>(pos) : threatsByPawn<WHITE>(pos);
+ // squares threatened by minors or pawns
+ threatenedByMinor = pos.side_to_move() == WHITE ? threatsByMinor<BLACK>(pos) : threatsByMinor<WHITE>(pos);
+ threatenedByMinor |= threatenedByPawn;
+ // squares threatened by rooks, minors or pawns
+ threatenedByRook = pos.side_to_move() == WHITE ? threatsByRook<BLACK>(pos) : threatsByRook<WHITE>(pos);
+ threatenedByRook |= threatenedByMinor;
+
+ // pieces threatened by pieces of lesser material value
+ threatened = pos.side_to_move() == WHITE ? ((pos.pieces(WHITE, QUEEN) & threatenedByRook) |
+ (pos.pieces(WHITE, ROOK) & threatenedByMinor) |
+ (pos.pieces(WHITE, KNIGHT, BISHOP) & threatenedByPawn))
+ : ((pos.pieces(BLACK, QUEEN) & threatenedByRook) |
+ (pos.pieces(BLACK, ROOK) & threatenedByMinor) |
+ (pos.pieces(BLACK, KNIGHT, BISHOP) & threatenedByPawn));
+ }
+ else
+ {
+ // Silence unused variable warning
+ (void) threatened;
+ (void) threatenedByPawn;
+ (void) threatenedByMinor;
+ (void) threatenedByRook;
+ }
+
for (auto& m : *this)
- if (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)))];
+ if constexpr (Type == CAPTURES)
+ m.value = 6 * int(PieceValue[MG][pos.piece_on(to_sq(m))])
+ + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))];
- else if (Type == QUIETS)
+ 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)]
- + 2 * (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
- + 2 * (*continuationHistory[3])[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);
+ + (threatened & from_sq(m) ?
+ (type_of(pos.piece_on(from_sq(m))) == QUEEN && !(to_sq(m) & threatenedByRook) ? 50000
+ : type_of(pos.piece_on(from_sq(m))) == ROOK && !(to_sq(m) & threatenedByMinor) ? 25000
+ : !(to_sq(m) & threatenedByPawn) ? 15000
+ : 0)
+ : 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);
}
}
}
/// 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) {
endMoves = generate<CAPTURES>(pos, cur);
score<CAPTURES>();
+ partial_insertion_sort(cur, endMoves, -3000 * depth);
++stage;
goto top;
case GOOD_CAPTURE:
- if (select<Best>([&](){
+ if (select<Next>([&](){
return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ?
// Move losing capture to endBadCaptures to be tried later
true : (*endBadCaptures++ = *cur, false); }))
return select<Best>([](){ return true; });
case PROBCUT:
- return select<Best>([&](){ return pos.see_ge(*cur, threshold); });
+ return select<Next>([&](){ return pos.see_ge(*cur, threshold); });
case QCAPTURE:
- if (select<Best>([&](){ return depth > DEPTH_QS_RECAPTURES
+ if (select<Next>([&](){ return depth > DEPTH_QS_RECAPTURES
|| to_sq(*cur) == recaptureSquare; }))
return *(cur - 1);
assert(false);
return MOVE_NONE; // Silence warning
}
+
+} // namespace Stockfish
projects / stockfish / blobdiff