namespace {
enum Stages {
- MAIN_SEARCH, GOOD_CAPTURES, KILLERS, QUIET, BAD_CAPTURES,
- EVASION, ALL_EVASIONS,
- QSEARCH_WITH_CHECKS, QCAPTURES_1, CHECKS,
- QSEARCH_WITHOUT_CHECKS, QCAPTURES_2,
- PROBCUT, PROBCUT_CAPTURES,
- RECAPTURE, RECAPTURES,
- STOP
+ MAIN_SEARCH, CAPTURES_INIT, GOOD_CAPTURES, KILLERS, COUNTERMOVE, QUIET_INIT, QUIET, BAD_CAPTURES,
+ EVASION, EVASIONS_INIT, ALL_EVASIONS,
+ PROBCUT, PROBCUT_INIT, PROBCUT_CAPTURES,
+ QSEARCH_WITH_CHECKS, QCAPTURES_1_INIT, QCAPTURES_1, QCHECKS,
+ QSEARCH_NO_CHECKS, QCAPTURES_2_INIT, QCAPTURES_2,
+ QSEARCH_RECAPTURES, QRECAPTURES
};
// Our insertion sort, which is guaranteed to be stable, as it should be
stage = pos.checkers() ? EVASION : MAIN_SEARCH;
ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
- endMoves += (ttMove != MOVE_NONE);
+ stage += (ttMove == MOVE_NONE);
}
MovePicker::MovePicker(const Position& p, Move ttm, Depth d, Square s)
stage = QSEARCH_WITH_CHECKS;
else if (d > DEPTH_QS_RECAPTURES)
- stage = QSEARCH_WITHOUT_CHECKS;
+ stage = QSEARCH_NO_CHECKS;
else
{
- stage = RECAPTURE;
+ stage = QSEARCH_RECAPTURES;
recaptureSquare = s;
- ttm = MOVE_NONE;
+ return;
}
ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
- endMoves += (ttMove != MOVE_NONE);
+ stage += (ttMove == MOVE_NONE);
}
MovePicker::MovePicker(const Position& p, Move ttm, Value th)
stage = PROBCUT;
- // In ProbCut we generate captures with SEE higher than the given threshold
+ // In ProbCut we generate captures with SEE higher than or equal to the given threshold
ttMove = ttm
&& pos.pseudo_legal(ttm)
&& pos.capture(ttm)
- && pos.see(ttm) > threshold ? ttm : MOVE_NONE;
+ && pos.see_ge(ttm, threshold)? ttm : MOVE_NONE;
- endMoves += (ttMove != MOVE_NONE);
+ stage += (ttMove == MOVE_NONE);
}
template<>
void MovePicker::score<QUIETS>() {
- const HistoryStats& history = pos.this_thread()->history;
+ const FromToStats& fromTo = pos.this_thread()->fromTo;
- const CounterMoveStats* cm = (ss-1)->counterMoves;
- const CounterMoveStats* fm = (ss-2)->counterMoves;
- const CounterMoveStats* f2 = (ss-4)->counterMoves;
+ const CounterMoveStats* cmh = (ss-1)->counterMoves;
+ const CounterMoveStats* fmh = (ss-2)->counterMoves;
+ const CounterMoveStats* fmh2 = (ss-4)->counterMoves;
+
+ Color c = pos.side_to_move();
for (auto& m : *this)
- m.value = history[pos.moved_piece(m)][to_sq(m)]
- + (cm ? (*cm)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
- + (fm ? (*fm)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
- + (f2 ? (*f2)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO);
+ m.value = (cmh ? (*cmh)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
+ + (fmh ? (*fmh)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
+ + (fmh2 ? (*fmh2)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO)
+ + fromTo.get(c, m);
}
template<>
void MovePicker::score<EVASIONS>() {
- // Try winning and equal captures ordered by MVV/LVA, then non-captures ordered
- // by history value, then bad captures and quiet moves with a negative SEE ordered
- // by SEE value.
- const HistoryStats& history = pos.this_thread()->history;
- Value see;
+ // Try captures ordered by MVV/LVA, then non-captures ordered by stats heuristics
+ const FromToStats& fromTo = pos.this_thread()->fromTo;
+ Color c = pos.side_to_move();
for (auto& m : *this)
- if ((see = pos.see_sign(m)) < VALUE_ZERO)
- m.value = see - HistoryStats::Max; // At the bottom
-
- else if (pos.capture(m))
+ if (pos.capture(m))
m.value = PieceValue[MG][pos.piece_on(to_sq(m))]
- - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max;
+ - Value(type_of(pos.moved_piece(m))) + FromToStats::Max;
else
- m.value = history[pos.moved_piece(m)][to_sq(m)];
+ m.value = fromTo.get(c, m);
}
-/// generate_next_stage() generates, scores, and sorts the next bunch of moves
-/// when there are no more moves to try for the current stage.
+/// 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 value from a list of generated moves
+/// taking care not to return the ttMove if it has already been searched.
-void MovePicker::generate_next_stage() {
+Move MovePicker::next_move() {
- assert(stage != STOP);
+ Move move;
- cur = moves;
+ switch (stage) {
- switch (++stage) {
+ case MAIN_SEARCH: case EVASION: case QSEARCH_WITH_CHECKS:
+ case QSEARCH_NO_CHECKS: case PROBCUT:
+ ++stage;
+ return ttMove;
- case GOOD_CAPTURES: case QCAPTURES_1: case QCAPTURES_2:
- case PROBCUT_CAPTURES: case RECAPTURES:
- endMoves = generate<CAPTURES>(pos, moves);
+ case CAPTURES_INIT:
+ endBadCaptures = cur = moves;
+ endMoves = generate<CAPTURES>(pos, cur);
score<CAPTURES>();
- break;
+ ++stage;
- case KILLERS:
- killers[0] = ss->killers[0];
- killers[1] = ss->killers[1];
- killers[2] = countermove;
- cur = killers;
- endMoves = cur + 2 + (countermove != killers[0] && countermove != killers[1]);
- break;
+ case GOOD_CAPTURES:
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if (move != ttMove)
+ {
+ if (pos.see_ge(move, VALUE_ZERO))
+ return move;
- case QUIET:
- endMoves = generate<QUIETS>(pos, moves);
+ // Losing capture, move it to the beginning of the array
+ *endBadCaptures++ = move;
+ }
+ }
+
+ ++stage;
+ move = ss->killers[0]; // First killer move
+ if ( move != MOVE_NONE
+ && move != ttMove
+ && pos.pseudo_legal(move)
+ && !pos.capture(move))
+ return move;
+
+ case KILLERS:
+ ++stage;
+ move = ss->killers[1]; // Second killer move
+ if ( move != MOVE_NONE
+ && move != ttMove
+ && pos.pseudo_legal(move)
+ && !pos.capture(move))
+ return move;
+
+ case COUNTERMOVE:
+ ++stage;
+ move = countermove;
+ if ( move != MOVE_NONE
+ && move != ttMove
+ && move != ss->killers[0]
+ && move != ss->killers[1]
+ && pos.pseudo_legal(move)
+ && !pos.capture(move))
+ return move;
+
+ case QUIET_INIT:
+ cur = endBadCaptures;
+ endMoves = generate<QUIETS>(pos, cur);
score<QUIETS>();
if (depth < 3 * ONE_PLY)
{
insertion_sort(cur, goodQuiet);
} else
insertion_sort(cur, endMoves);
- break;
+ ++stage;
+
+ case QUIET:
+ while (cur < endMoves)
+ {
+ move = *cur++;
+ if ( move != ttMove
+ && move != ss->killers[0]
+ && move != ss->killers[1]
+ && move != countermove)
+ return move;
+ }
+ ++stage;
+ cur = moves; // Point to beginning of bad captures
case BAD_CAPTURES:
- // Just pick them in reverse order to get correct ordering
- cur = moves + MAX_MOVES - 1;
- endMoves = endBadCaptures;
+ if (cur < endBadCaptures)
+ return *cur++;
break;
+ case EVASIONS_INIT:
+ cur = moves;
+ endMoves = generate<EVASIONS>(pos, cur);
+ score<EVASIONS>();
+ ++stage;
+
case ALL_EVASIONS:
- endMoves = generate<EVASIONS>(pos, moves);
- if (endMoves - moves > 1)
- score<EVASIONS>();
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if (move != ttMove)
+ return move;
+ }
break;
- case CHECKS:
- endMoves = generate<QUIET_CHECKS>(pos, moves);
- break;
+ case PROBCUT_INIT:
+ cur = moves;
+ endMoves = generate<CAPTURES>(pos, cur);
+ score<CAPTURES>();
+ ++stage;
- case EVASION: case QSEARCH_WITH_CHECKS: case QSEARCH_WITHOUT_CHECKS:
- case PROBCUT: case RECAPTURE: case STOP:
- stage = STOP;
+ case PROBCUT_CAPTURES:
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if ( move != ttMove
+ && pos.see_ge(move, threshold))
+ return move;
+ }
break;
- default:
- assert(false);
- }
-}
-
-
-/// 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 value from a list of generated moves
-/// taking care not to return the ttMove if it has already been searched.
-
-Move MovePicker::next_move() {
-
- Move move;
-
- while (true)
- {
- while (cur == endMoves && stage != STOP)
- generate_next_stage();
-
- switch (stage) {
-
- case MAIN_SEARCH: case EVASION: case QSEARCH_WITH_CHECKS:
- case QSEARCH_WITHOUT_CHECKS: case PROBCUT:
- ++cur;
- return ttMove;
+ case QCAPTURES_1_INIT: case QCAPTURES_2_INIT:
+ cur = moves;
+ endMoves = generate<CAPTURES>(pos, cur);
+ score<CAPTURES>();
+ ++stage;
- case GOOD_CAPTURES:
+ case QCAPTURES_1: case QCAPTURES_2:
+ while (cur < endMoves)
+ {
move = pick_best(cur++, endMoves);
if (move != ttMove)
- {
- if (pos.see_sign(move) >= VALUE_ZERO)
- return move;
-
- // Losing capture, move it to the tail of the array
- *endBadCaptures-- = move;
- }
- break;
-
- case KILLERS:
- move = *cur++;
- if ( move != MOVE_NONE
- && move != ttMove
- && pos.pseudo_legal(move)
- && !pos.capture(move))
- return move;
- break;
-
- case QUIET:
- move = *cur++;
- if ( move != ttMove
- && move != killers[0]
- && move != killers[1]
- && move != killers[2])
return move;
+ }
+ if (stage == QCAPTURES_2)
break;
+ cur = moves;
+ endMoves = generate<QUIET_CHECKS>(pos, cur);
+ ++stage;
- case BAD_CAPTURES:
- return *cur--;
-
- case ALL_EVASIONS: case QCAPTURES_1: case QCAPTURES_2:
- move = pick_best(cur++, endMoves);
+ case QCHECKS:
+ while (cur < endMoves)
+ {
+ move = cur++->move;
if (move != ttMove)
return move;
- break;
+ }
+ break;
- case PROBCUT_CAPTURES:
- move = pick_best(cur++, endMoves);
- if (move != ttMove && pos.see(move) > threshold)
- return move;
- break;
+ case QSEARCH_RECAPTURES:
+ cur = moves;
+ endMoves = generate<CAPTURES>(pos, cur);
+ score<CAPTURES>();
+ ++stage;
- case RECAPTURES:
+ case QRECAPTURES:
+ while (cur < endMoves)
+ {
move = pick_best(cur++, endMoves);
if (to_sq(move) == recaptureSquare)
return move;
- break;
-
- case CHECKS:
- move = *cur++;
- if (move != ttMove)
- return move;
- break;
-
- case STOP:
- return MOVE_NONE;
-
- default:
- assert(false);
}
+ break;
+
+ default:
+ assert(false);
}
+
+ return MOVE_NONE;
}
projects / stockfish / blobdiff