X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmovepick.cpp;h=2ea859a26fcf2b9ef4dadfe42d03c0806d082679;hb=ebe021f6a5da63cf0e31da89d4c21e9b5f673fcd;hp=6df070bbdf167b8e835a1970eb5099f846dbcfd7;hpb=bb751d6c890f5c50c642366d601740366cfae8d0;p=stockfish
diff --git a/src/movepick.cpp b/src/movepick.cpp
index 6df070bb..2ea859a2 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -1,503 +1,349 @@
/*
- Glaurung, a UCI chess playing engine.
- Copyright (C) 2004-2008 Tord Romstad
+ 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) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
- Glaurung is free software: you can redistribute it and/or modify
+ Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-
- Glaurung is distributed in the hope that it will be useful,
+
+ Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
-
-////
-//// Includes
-////
-
#include
-#include "history.h"
-#include "movegen.h"
#include "movepick.h"
-#include "search.h"
-#include "value.h"
-
-
-////
-//// Local definitions
-////
+#include "thread.h"
namespace {
- /// Types
-
- enum MovegenPhase {
- PH_TT_MOVE, // Transposition table move
- PH_MATE_KILLER, // Mate killer from the current ply
- PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= 0
- PH_BAD_CAPTURES, // Queen promotions and captures with SEE valuse <= 0
- PH_KILLER_1, // Killer move 1 from the current ply (not used yet).
- PH_KILLER_2, // Killer move 2 from the current ply (not used yet).
- PH_NONCAPTURES, // Non-captures and underpromotions
- PH_EVASIONS, // Check evasions
- PH_QCAPTURES, // Captures in quiescence search
- PH_QCHECKS, // Checks in quiescence search
- PH_STOP
+ enum Stages {
+ 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
+ void insertion_sort(ExtMove* begin, ExtMove* end)
+ {
+ ExtMove tmp, *p, *q;
+
+ for (p = begin + 1; p < end; ++p)
+ {
+ tmp = *p;
+ for (q = p; q != begin && *(q-1) < tmp; --q)
+ *q = *(q-1);
+ *q = tmp;
+ }
+ }
- /// Variables
-
- MovegenPhase PhaseTable[32];
- int MainSearchPhaseIndex;
- int EvasionsPhaseIndex;
- int QsearchWithChecksPhaseIndex;
- int QsearchWithoutChecksPhaseIndex;
-
-}
-
+ // pick_best() finds 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 moves, e.g., the possible captures.
+ Move pick_best(ExtMove* begin, ExtMove* end)
+ {
+ std::swap(*begin, *std::max_element(begin, end));
+ return *begin;
+ }
-////
-//// Functions
-////
+} // namespace
-/// Constructor for the MovePicker class. Apart from the position for which
-/// it is asked to pick legal moves, MovePicker also wants some information
-/// to help it to return the presumably good moves first, to decide which
+/// Constructors of the MovePicker class. As arguments we pass information
+/// to help it to return the (presumably) good moves first, to decide which
/// moves to return (in the quiescence search, for instance, we only want to
-/// search captures, promotions and some checks) and about how important good
-/// move ordering is at the current node.
-
-MovePicker::MovePicker(Position &p, bool pvnode, Move ttm, Move mk,
- Move k1, Move k2, Depth dpth) {
- pos = &p;
- pvNode = pvnode;
- ttMove = ttm;
- mateKiller = (mk == ttm)? MOVE_NONE : mk;
- killer1 = k1;
- killer2 = k2;
- depth = dpth;
- movesPicked = 0;
- numOfMoves = 0;
- numOfBadCaptures = 0;
- dc = p.discovered_check_candidates(p.side_to_move());
-
- if(p.is_check())
- phaseIndex = EvasionsPhaseIndex;
- else if(depth > Depth(0))
- phaseIndex = MainSearchPhaseIndex;
- else if(depth == Depth(0))
- phaseIndex = QsearchWithChecksPhaseIndex;
- else
- phaseIndex = QsearchWithoutChecksPhaseIndex;
-
- pinned = p.pinned_pieces(p.side_to_move());
-
- finished = false;
-}
+/// search captures, promotions, and some checks) and how important good move
+/// ordering is at the current node.
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, Search::Stack* s)
+ : pos(p), ss(s), depth(d) {
-/// MovePicker::get_next_move() is the most important method of the MovePicker
-/// class. It returns a new legal move every time it is called, until there
-/// are no more moves left of the types we are interested in.
+ assert(d > DEPTH_ZERO);
-Move MovePicker::get_next_move() {
- Move move;
+ Square prevSq = to_sq((ss-1)->currentMove);
+ countermove = pos.this_thread()->counterMoves[pos.piece_on(prevSq)][prevSq];
- while(true) {
- // If we already have a list of generated moves, pick the best move from
- // the list, and return it:
- move = this->pick_move_from_list();
- if(move != MOVE_NONE) {
- assert(move_is_ok(move));
- return move;
- }
+ stage = pos.checkers() ? EVASION : MAIN_SEARCH;
+ ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
+ stage += (ttMove == MOVE_NONE);
+}
- // Next phase:
- phaseIndex++;
- switch(PhaseTable[phaseIndex]) {
-
- case PH_TT_MOVE:
- if(ttMove != MOVE_NONE) {
- assert(move_is_ok(ttMove));
- Move m = generate_move_if_legal(*pos, ttMove, pinned);
- if(m != MOVE_NONE) {
- assert(m == ttMove);
- return m;
- }
- }
- break;
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, Square s)
+ : pos(p) {
- case PH_MATE_KILLER:
- if(mateKiller != MOVE_NONE) {
- assert(move_is_ok(mateKiller));
- Move m = generate_move_if_legal(*pos, mateKiller, pinned);
- if(m != MOVE_NONE) {
- assert(m == mateKiller);
- return m;
- }
- }
- break;
+ assert(d <= DEPTH_ZERO);
- case PH_GOOD_CAPTURES:
- // pinned = pos->pinned_pieces(pos->side_to_move());
- numOfMoves = generate_captures(*pos, moves);
- this->score_captures();
- movesPicked = 0;
- break;
+ if (pos.checkers())
+ stage = EVASION;
- case PH_BAD_CAPTURES:
- badCapturesPicked = 0;
- break;
+ else if (d > DEPTH_QS_NO_CHECKS)
+ stage = QSEARCH_WITH_CHECKS;
- case PH_NONCAPTURES:
- numOfMoves = generate_noncaptures(*pos, moves);
- this->score_noncaptures();
- movesPicked = 0;
- break;
+ else if (d > DEPTH_QS_RECAPTURES)
+ stage = QSEARCH_NO_CHECKS;
- case PH_EVASIONS:
- assert(pos->is_check());
- // pinned = pos->pinned_pieces(pos->side_to_move());
- numOfMoves = generate_evasions(*pos, moves);
- this->score_evasions();
- movesPicked = 0;
- break;
+ else
+ {
+ stage = QSEARCH_RECAPTURES;
+ recaptureSquare = s;
+ return;
+ }
- case PH_QCAPTURES:
- // pinned = pos->pinned_pieces(pos->side_to_move());
- numOfMoves = generate_captures(*pos, moves);
- this->score_qcaptures();
- movesPicked = 0;
- break;
+ ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
+ stage += (ttMove == MOVE_NONE);
+}
- case PH_QCHECKS:
- numOfMoves = generate_checks(*pos, moves, dc);
- movesPicked = 0;
- break;
+MovePicker::MovePicker(const Position& p, Move ttm, Value th)
+ : pos(p), threshold(th) {
- case PH_STOP:
- return MOVE_NONE;
+ assert(!pos.checkers());
- default:
- assert(false);
- return MOVE_NONE;
- }
- }
+ stage = PROBCUT;
- assert(false);
+ // 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_ge(ttm, threshold)? ttm : MOVE_NONE;
- return MOVE_NONE;
+ stage += (ttMove == MOVE_NONE);
}
-/// A variant of get_next_move() which takes a lock as a parameter, used to
-/// prevent multiple threads from picking the same move at a split point.
-
-Move MovePicker::get_next_move(Lock &lock) {
- Move m;
-
- lock_grab(&lock);
- if(finished) {
- lock_release(&lock);
- return MOVE_NONE;
- }
- m = this->get_next_move();
- if(m == MOVE_NONE)
- finished = true;
- lock_release(&lock);
-
- return m;
+/// score() assigns a numerical value to each move in a move list. The moves with
+/// highest values will be picked first.
+template<>
+void MovePicker::score() {
+ // Winning and equal captures in the main search are ordered by MVV, preferring
+ // captures near our home rank. Surprisingly, this appears to perform slightly
+ // better than SEE-based move ordering: exchanging big pieces before capturing
+ // a hanging piece probably helps to reduce the subtree size.
+ // In the main search we want to push captures with negative SEE values to the
+ // badCaptures[] array, but instead of doing it now we delay until the move
+ // has been picked up, saving some SEE calls in case we get a cutoff.
+ for (auto& m : *this)
+ m.value = PieceValue[MG][pos.piece_on(to_sq(m))]
+ - Value(200 * relative_rank(pos.side_to_move(), to_sq(m)));
}
-
-/// MovePicker::number_of_moves() simply returns the numOfMoves member
-/// variable. It is intended to be used in positions where the side to move
-/// is in check, for detecting checkmates or situations where there is only
-/// a single reply to check.
+template<>
+void MovePicker::score() {
-int MovePicker::number_of_moves() const {
- return numOfMoves;
-}
+ const HistoryStats& history = pos.this_thread()->history;
+ const CounterMoveStats& cmh = *(ss-1)->counterMoves;
+ const CounterMoveStats& fmh = *(ss-2)->counterMoves;
+ const CounterMoveStats& fm2 = *(ss-4)->counterMoves;
-/// MovePicker::score_captures(), MovePicker::score_noncaptures(),
-/// MovePicker::score_evasions() and MovePicker::score_qcaptures() assign a
-/// numerical move ordering score to each move in a move list. The moves
-/// with highest scores will be picked first by
-/// MovePicker::pick_move_from_list().
-
-void MovePicker::score_captures() {
- // Winning and equal captures in the main search are ordered by MVV/LVA.
- // Suprisingly, this appears to perform slightly better than SEE based
- // move ordering. The reason is probably that in a position with a winning
- // capture, capturing a more valuable (but sufficiently defended) piece
- // first usually doesn't hurt. The opponent will have to recapture, and
- // the hanging piece will still be hanging (except in the unusual cases
- // where it is possible to recapture with the hanging piece). Exchanging
- // big pieces before capturing a hanging piece probably helps to reduce
- // the subtree size.
- for(int i = 0; i < numOfMoves; i++) {
- int seeValue = pos->see(moves[i].move);
- if(seeValue >= 0) {
- if(move_promotion(moves[i].move))
- moves[i].score = QueenValueMidgame;
- else
- moves[i].score =
- int(pos->midgame_value_of_piece_on(move_to(moves[i].move))) -
- int(pos->type_of_piece_on(move_from(moves[i].move)));
- }
- else
- moves[i].score = seeValue;
-
- }
-}
+ Color c = pos.side_to_move();
-void MovePicker::score_noncaptures() {
- for(int i = 0; i < numOfMoves; i++) {
- Move m = moves[i].move;
- if(m == killer1)
- moves[i].score = HistoryMax + 2;
- else if(m == killer2)
- moves[i].score = HistoryMax + 1;
- else
- moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m);
- }
+ for (auto& m : *this)
+ m.value = cmh[pos.moved_piece(m)][to_sq(m)]
+ + fmh[pos.moved_piece(m)][to_sq(m)]
+ + fm2[pos.moved_piece(m)][to_sq(m)]
+ + history.get(c, m);
}
-void MovePicker::score_evasions() {
- for(int i = 0; i < numOfMoves; i++) {
- Move m = moves[i].move;
- if(m == ttMove)
- moves[i].score = 2*HistoryMax;
- else if(!pos->square_is_empty(move_to(m))) {
- int seeScore = pos->see(m);
- moves[i].score = (seeScore >= 0)? seeScore + HistoryMax : seeScore;
- }
- else
- moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m);
- }
-}
+template<>
+void MovePicker::score() {
+ // Try captures ordered by MVV/LVA, then non-captures ordered by stats heuristics
+ const HistoryStats& history = pos.this_thread()->history;
+ Color c = pos.side_to_move();
-void MovePicker::score_qcaptures() {
- // Use MVV/LVA ordering.
- for(int i = 0; i < numOfMoves; i++) {
- Move m = moves[i].move;
- if(move_promotion(m))
- moves[i].score = QueenValueMidgame;
- else
- moves[i].score =
- int(pos->midgame_value_of_piece_on(move_to(m))) -
- int(pos->midgame_value_of_piece_on(move_to(m))) / 64;
- }
+ for (auto& m : *this)
+ if (pos.capture(m))
+ m.value = PieceValue[MG][pos.piece_on(to_sq(m))]
+ - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max;
+ else
+ m.value = history.get(c, m);
}
-/// MovePicker::pick_move_from_list() picks the move with the biggest score
-/// from a list of generated moves (moves[] or badCaptures[], depending on
-/// the current move generation phase). It takes care not to return the
-/// transposition table move if that has already been serched previously.
-/// While picking captures in the PH_GOOD_CAPTURES phase (i.e. while picking
-/// non-losing captures in the main search), it moves all captures with
-/// negative SEE values to the badCaptures[] array.
+/// 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(bool skipQuiets) {
-Move MovePicker::pick_move_from_list() {
- int bestScore = -10000000;
- int bestIndex;
Move move;
- switch(PhaseTable[phaseIndex]) {
-
- case PH_GOOD_CAPTURES:
- assert(!pos->is_check());
- assert(movesPicked >= 0);
- while(movesPicked < numOfMoves) {
- bestScore = -10000000;
- bestIndex = -1;
- for(int i = movesPicked; i < numOfMoves; i++) {
- if(moves[i].score < 0) {
- // Losing capture, move it to the badCaptures[] array
- assert(numOfBadCaptures < 63);
- badCaptures[numOfBadCaptures++] = moves[i];
- moves[i--] = moves[--numOfMoves];
- }
- else if(moves[i].score > bestScore) {
- bestIndex = i;
- bestScore = moves[i].score;
- }
- }
- if(bestIndex != -1) { // Found a good capture
- MoveStack tmp = moves[movesPicked];
- moves[movesPicked] = moves[bestIndex];
- moves[bestIndex] = tmp;
- move = moves[movesPicked++].move;
- if(move != ttMove && move != mateKiller &&
- pos->move_is_legal(move, pinned))
- return move;
- }
- }
- break;
-
- case PH_NONCAPTURES:
- assert(!pos->is_check());
- assert(movesPicked >= 0);
- while(movesPicked < numOfMoves) {
- bestScore = -10000000;
-
- // If this is a PV node or we have only picked a few moves, scan
- // the entire move list for the best move. If many moves have already
- // been searched and it is not a PV node, we are probably failing low
- // anyway, so we just pick the first move from the list.
- if(pvNode || movesPicked < 12) {
- bestIndex = -1;
- for(int i = movesPicked; i < numOfMoves; i++)
- if(moves[i].score > bestScore) {
- bestIndex = i;
- bestScore = moves[i].score;
+ switch (stage) {
+
+ case MAIN_SEARCH: case EVASION: case QSEARCH_WITH_CHECKS:
+ case QSEARCH_NO_CHECKS: case PROBCUT:
+ ++stage;
+ return ttMove;
+
+ case CAPTURES_INIT:
+ endBadCaptures = cur = moves;
+ endMoves = generate(pos, cur);
+ score();
+ ++stage;
+
+ case GOOD_CAPTURES:
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if (move != ttMove)
+ {
+ if (pos.see_ge(move, VALUE_ZERO))
+ return move;
+
+ // Losing capture, move it to the beginning of the array
+ *endBadCaptures++ = move;
}
}
- else
- bestIndex = movesPicked;
-
- if(bestIndex != -1) {
- MoveStack tmp = moves[movesPicked];
- moves[movesPicked] = moves[bestIndex];
- moves[bestIndex] = tmp;
- move = moves[movesPicked++].move;
- if(move != ttMove && move != mateKiller &&
- pos->move_is_legal(move, pinned))
+
+ ++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(pos, cur);
+ score();
+ if (depth < 3 * ONE_PLY)
+ {
+ ExtMove* goodQuiet = std::partition(cur, endMoves, [](const ExtMove& m)
+ { return m.value > VALUE_ZERO; });
+ insertion_sort(cur, goodQuiet);
+ } else
+ insertion_sort(cur, endMoves);
+ ++stage;
+
+ case QUIET:
+ while ( cur < endMoves
+ && (!skipQuiets || cur->value >= VALUE_ZERO))
+ {
+ move = *cur++;
+
+ if ( move != ttMove
+ && move != ss->killers[0]
+ && move != ss->killers[1]
+ && move != countermove)
+ return move;
}
- }
- break;
-
- case PH_EVASIONS:
- assert(pos->is_check());
- assert(movesPicked >= 0);
- while(movesPicked < numOfMoves) {
- bestScore = -10000000;
- bestIndex = -1;
- for(int i = movesPicked; i < numOfMoves; i++)
- if(moves[i].score > bestScore) {
- bestIndex = i;
- bestScore = moves[i].score;
- }
-
- if(bestIndex != -1) {
- MoveStack tmp = moves[movesPicked];
- moves[movesPicked] = moves[bestIndex];
- moves[bestIndex] = tmp;
- move = moves[movesPicked++].move;
- return move;
+ ++stage;
+ cur = moves; // Point to beginning of bad captures
+
+ case BAD_CAPTURES:
+ if (cur < endBadCaptures)
+ return *cur++;
+ break;
+
+ case EVASIONS_INIT:
+ cur = moves;
+ endMoves = generate(pos, cur);
+ score();
+ ++stage;
+
+ case ALL_EVASIONS:
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if (move != ttMove)
+ return move;
}
- }
- break;
-
- case PH_BAD_CAPTURES:
- assert(!pos->is_check());
- assert(badCapturesPicked >= 0);
- // It's probably a good idea to use SEE move ordering here, instead
- // of just picking the first move. FIXME
- while(badCapturesPicked < numOfBadCaptures) {
- move = badCaptures[badCapturesPicked++].move;
- if(move != ttMove && move != mateKiller &&
- pos->move_is_legal(move, pinned))
- return move;
- }
- break;
-
- case PH_QCAPTURES:
- assert(!pos->is_check());
- assert(movesPicked >= 0);
- while(movesPicked < numOfMoves) {
- bestScore = -10000000;
- if(movesPicked < 4) {
- bestIndex = -1;
- for(int i = movesPicked; i < numOfMoves; i++)
- if(moves[i].score > bestScore) {
- bestIndex = i;
- bestScore = moves[i].score;
- }
+ break;
+
+ case PROBCUT_INIT:
+ cur = moves;
+ endMoves = generate(pos, cur);
+ score();
+ ++stage;
+
+ case PROBCUT_CAPTURES:
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if ( move != ttMove
+ && pos.see_ge(move, threshold))
+ return move;
}
- else
- bestIndex = movesPicked;
+ break;
- if(bestIndex != -1) {
- MoveStack tmp = moves[movesPicked];
- moves[movesPicked] = moves[bestIndex];
- moves[bestIndex] = tmp;
+ case QCAPTURES_1_INIT: case QCAPTURES_2_INIT:
+ cur = moves;
+ endMoves = generate(pos, cur);
+ score();
+ ++stage;
+
+ case QCAPTURES_1: case QCAPTURES_2:
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if (move != ttMove)
+ return move;
+ }
+ if (stage == QCAPTURES_2)
+ break;
+ cur = moves;
+ endMoves = generate(pos, cur);
+ ++stage;
+
+ case QCHECKS:
+ while (cur < endMoves)
+ {
+ move = cur++->move;
+ if (move != ttMove)
+ return move;
+ }
+ break;
- move = moves[movesPicked++].move;
- // Remember to change the line below if we decide to hash the qsearch!
- // Maybe also postpone the legality check until after futility pruning?
- if(/* move != ttMove && */ pos->move_is_legal(move, pinned))
- return move;
+ case QSEARCH_RECAPTURES:
+ cur = moves;
+ endMoves = generate(pos, cur);
+ score();
+ ++stage;
+
+ case QRECAPTURES:
+ while (cur < endMoves)
+ {
+ move = pick_best(cur++, endMoves);
+ if (to_sq(move) == recaptureSquare)
+ return move;
}
- }
- break;
-
- case PH_QCHECKS:
- assert(!pos->is_check());
- assert(movesPicked >= 0);
- // Perhaps we should do something better than just picking the first
- // move here? FIXME
- while(movesPicked < numOfMoves) {
- move = moves[movesPicked++].move;
- // Remember to change the line below if we decide to hash the qsearch!
- if(/* move != ttMove && */ pos->move_is_legal(move, pinned))
- return move;
- }
- break;
+ break;
default:
- break;
+ assert(false);
}
return MOVE_NONE;
}
-
-
-/// MovePicker::init_phase_table() initializes the PhaseTable[],
-/// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex
-/// and QsearchWithoutChecksPhaseIndex variables. It is only called once
-/// during program startup, and never again while the program is running.
-
-void MovePicker::init_phase_table() {
- int i = 0;
-
- // Main search
- MainSearchPhaseIndex = i - 1;
- PhaseTable[i++] = PH_TT_MOVE;
- PhaseTable[i++] = PH_MATE_KILLER;
- PhaseTable[i++] = PH_GOOD_CAPTURES;
- // PH_KILLER_1 and PH_KILLER_2 are not yet used.
- // PhaseTable[i++] = PH_KILLER_1;
- // PhaseTable[i++] = PH_KILLER_2;
- PhaseTable[i++] = PH_NONCAPTURES;
- PhaseTable[i++] = PH_BAD_CAPTURES;
- PhaseTable[i++] = PH_STOP;
-
- // Check evasions
- EvasionsPhaseIndex = i - 1;
- PhaseTable[i++] = PH_EVASIONS;
- PhaseTable[i++] = PH_STOP;
-
- // Quiescence search with checks
- QsearchWithChecksPhaseIndex = i - 1;
- PhaseTable[i++] = PH_QCAPTURES;
- PhaseTable[i++] = PH_QCHECKS;
- PhaseTable[i++] = PH_STOP;
-
- // Quiescence search without checks
- QsearchWithoutChecksPhaseIndex = i - 1;
- PhaseTable[i++] = PH_QCAPTURES;
- PhaseTable[i++] = PH_STOP;
-}