/// Variables
- MovePicker::MovegenPhase PhaseTable[32];
- int MainSearchPhaseIndex;
- int EvasionsPhaseIndex;
- int QsearchWithChecksPhaseIndex;
- int QsearchWithoutChecksPhaseIndex;
-
+ CACHE_LINE_ALIGNMENT
+ const MovegenPhaseT MainSearchPhaseTable[] = { PH_STOP, PH_NULL_MOVE, PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
+ const MovegenPhaseT MainSearchNoNullPhaseTable[] = { PH_STOP, PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
+ const MovegenPhaseT LowSearchPhaseTable[] = { PH_STOP, PH_TT_MOVES, PH_GOOD_CAPTURES, PH_NULL_MOVE, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
+ const MovegenPhaseT EvasionsPhaseTable[] = { PH_STOP, PH_EVASIONS, PH_STOP};
+ const MovegenPhaseT QsearchWithChecksPhaseTable[] = { PH_STOP, PH_TT_MOVES, PH_QCAPTURES, PH_QCHECKS, PH_STOP};
+ const MovegenPhaseT QsearchWithoutChecksPhaseTable[] = { PH_STOP, PH_TT_MOVES, PH_QCAPTURES, PH_STOP};
}
/// move ordering is at the current node.
MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
- const History& h, SearchStack* ss) : pos(p), H(h) {
- ttMove = ttm;
+ const History& h, SearchStack* ss, bool useNullMove) : pos(p), H(h) {
+ ttMoves[0] = ttm;
if (ss)
{
- mateKiller = (ss->mateKiller == ttm)? MOVE_NONE : ss->mateKiller;
- killer1 = ss->killers[0];
- killer2 = ss->killers[1];
+ ttMoves[1] = (ss->mateKiller == ttm)? MOVE_NONE : ss->mateKiller;
+ killers[0] = ss->killers[0];
+ killers[1] = ss->killers[1];
} else
- mateKiller = killer1 = killer2 = MOVE_NONE;
+ ttMoves[1] = killers[0] = killers[1] = MOVE_NONE;
movesPicked = numOfMoves = numOfBadCaptures = 0;
- checkKillers = checkLegal = finished = false;
+ finished = false;
if (p.is_check())
- phaseIndex = EvasionsPhaseIndex;
+ phasePtr = EvasionsPhaseTable;
+ else if (d >= Depth(3 * OnePly))
+ phasePtr = useNullMove ? MainSearchPhaseTable : MainSearchNoNullPhaseTable;
else if (d > Depth(0))
- phaseIndex = MainSearchPhaseIndex;
+ phasePtr = useNullMove ? LowSearchPhaseTable : MainSearchNoNullPhaseTable;
else if (d == Depth(0))
- phaseIndex = QsearchWithChecksPhaseIndex;
+ phasePtr = QsearchWithChecksPhaseTable;
else
- phaseIndex = QsearchWithoutChecksPhaseIndex;
+ phasePtr = QsearchWithoutChecksPhaseTable;
Color us = pos.side_to_move();
dc = p.discovered_check_candidates(us);
pinned = p.pinned_pieces(us);
-
- finished = false;
}
}
// Next phase
- phaseIndex++;
- switch (PhaseTable[phaseIndex]) {
-
- case PH_TT_MOVE:
- if (ttMove != MOVE_NONE)
- {
- assert(move_is_ok(ttMove));
- if (move_is_legal(pos, ttMove, pinned))
- return ttMove;
- }
- break;
+ phasePtr++;
+ switch (*phasePtr) {
- case PH_MATE_KILLER:
- if (mateKiller != MOVE_NONE)
- {
- assert(move_is_ok(mateKiller));
- if (move_is_legal(pos, mateKiller, pinned))
- return mateKiller;
- }
+ case PH_NULL_MOVE:
+ return MOVE_NULL;
+
+ case PH_TT_MOVES:
+ movesPicked = 0; // This is used as index to ttMoves[]
break;
case PH_GOOD_CAPTURES:
score_captures();
std::sort(moves, moves + numOfMoves);
movesPicked = 0;
- checkLegal = true;
break;
case PH_KILLERS:
- movesPicked = numOfMoves = 0;
- checkLegal = false;
- if (killer1 != MOVE_NONE && move_is_legal(pos, killer1, pinned) && !pos.move_is_capture(killer1))
- moves[numOfMoves++].move = killer1;
- if (killer2 != MOVE_NONE && move_is_legal(pos, killer2, pinned) && !pos.move_is_capture(killer2) )
- moves[numOfMoves++].move = killer2;
+ movesPicked = 0; // This is used as index to killers[]
break;
case PH_NONCAPTURES:
- checkKillers = (numOfMoves != 0); // previous phase is PH_KILLERS
numOfMoves = generate_noncaptures(pos, moves);
score_noncaptures();
std::sort(moves, moves + numOfMoves);
movesPicked = 0;
- checkLegal = true;
break;
case PH_BAD_CAPTURES:
- // Bad captures SEE value is already calculated by score_captures()
- // so just sort them to get SEE move ordering.
+ // Bad captures SEE value is already calculated so just sort them
+ // to get SEE move ordering.
std::sort(badCaptures, badCaptures + numOfBadCaptures);
movesPicked = 0;
break;
case PH_QCAPTURES:
numOfMoves = generate_captures(pos, moves);
- score_qcaptures();
+ score_captures();
std::sort(moves, moves + numOfMoves);
movesPicked = 0;
break;
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
+ // 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
+ // 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.
- // While scoring captures it moves all captures with negative SEE values
- // to the badCaptures[] array.
+ // In main search we want to push captures with negative SEE values to
+ // badCaptures[] array, but instead of doing it now we delay till when
+ // the move has been picked up in pick_move_from_list(), this way we save
+ // some SEE calls in case we get a cutoff (idea from Pablo Vazquez).
Move m;
- int seeValue;
+ // Use MVV/LVA ordering
for (int i = 0; i < numOfMoves; i++)
{
m = moves[i].move;
- seeValue = pos.see(m);
- if (seeValue >= 0)
- {
- if (move_is_promotion(m))
- moves[i].score = QueenValueMidgame;
- else
- moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
- -int(pos.type_of_piece_on(move_from(m)));
- }
+ if (move_is_promotion(m))
+ moves[i].score = QueenValueMidgame;
else
- {
- // Losing capture, move it to the badCaptures[] array
- assert(numOfBadCaptures < 63);
- moves[i].score = seeValue;
- badCaptures[numOfBadCaptures++] = moves[i];
- moves[i--] = moves[--numOfMoves];
- }
+ moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
+ -int(pos.type_of_piece_on(move_from(m)));
}
}
for (int i = 0; i < numOfMoves; i++)
{
Move m = moves[i].move;
- if (m == ttMove)
+ if (m == ttMoves[0])
moves[i].score = 2*HistoryMax;
else if (!pos.square_is_empty(move_to(m)))
{
}
}
-void MovePicker::score_qcaptures() {
-
- // Use MVV/LVA ordering
- for (int i = 0; i < numOfMoves; i++)
- {
- Move m = moves[i].move;
- if (move_is_promotion(m))
- moves[i].score = QueenValueMidgame;
- else
- moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m)))
- -int(pos.type_of_piece_on(move_from(m)));
- }
-}
-
/// MovePicker::pick_move_from_list() picks the move with the biggest score
/// from a list of generated moves (moves[] or badCaptures[], depending on
Move MovePicker::pick_move_from_list() {
assert(movesPicked >= 0);
- assert(!pos.is_check() || PhaseTable[phaseIndex] == PH_EVASIONS || PhaseTable[phaseIndex] == PH_STOP);
- assert( pos.is_check() || PhaseTable[phaseIndex] != PH_EVASIONS);
+ assert(!pos.is_check() || *phasePtr == PH_EVASIONS || *phasePtr == PH_STOP);
+ assert( pos.is_check() || *phasePtr != PH_EVASIONS);
- switch (PhaseTable[phaseIndex]) {
+ switch (*phasePtr) {
+
+ case PH_TT_MOVES:
+ while (movesPicked < 2) {
+ Move move = ttMoves[movesPicked++];
+ if ( move != MOVE_NONE
+ && move_is_legal(pos, move, pinned))
+ return move;
+ }
+ break;
case PH_GOOD_CAPTURES:
+ while (movesPicked < numOfMoves)
+ {
+ Move move = moves[movesPicked++].move;
+ if ( move != ttMoves[0]
+ && move != ttMoves[1]
+ && pos.pl_move_is_legal(move, pinned))
+ {
+ // Check for a non negative SEE now
+ int seeValue = pos.see_sign(move);
+ if (seeValue >= 0)
+ return move;
+
+ // Losing capture, move it to the badCaptures[] array, note
+ // that move has now been already checked for legality.
+ assert(numOfBadCaptures < 63);
+ badCaptures[numOfBadCaptures].move = move;
+ badCaptures[numOfBadCaptures++].score = seeValue;
+ }
+ }
+ break;
+
case PH_KILLERS:
+ while (movesPicked < 2) {
+ Move move = killers[movesPicked++];
+ if ( move != MOVE_NONE
+ && move != ttMoves[0]
+ && move != ttMoves[1]
+ && move_is_legal(pos, move, pinned)
+ && !pos.move_is_capture(move))
+ return move;
+ }
+ break;
+
case PH_NONCAPTURES:
while (movesPicked < numOfMoves)
{
Move move = moves[movesPicked++].move;
- if ( move != ttMove
- && move != mateKiller
- && (!checkKillers || (move != killer1 && move != killer2))
- && (!checkLegal || pos.pl_move_is_legal(move, pinned)))
+ if ( move != ttMoves[0]
+ && move != ttMoves[1]
+ && move != killers[0]
+ && move != killers[1]
+ && pos.pl_move_is_legal(move, pinned))
return move;
}
break;
case PH_EVASIONS:
if (movesPicked < numOfMoves)
return moves[movesPicked++].move;
-
break;
case PH_BAD_CAPTURES:
- while (movesPicked < numOfBadCaptures)
- {
- Move move = badCaptures[movesPicked++].move;
- if ( move != ttMove
- && move != mateKiller
- && pos.pl_move_is_legal(move, pinned))
- return move;
- }
+ if (movesPicked < numOfBadCaptures)
+ return badCaptures[movesPicked++].move;
break;
case PH_QCAPTURES:
{
Move move = moves[movesPicked++].move;
// Maybe postpone the legality check until after futility pruning?
- if ( move != ttMove
+ if ( move != ttMoves[0]
&& pos.pl_move_is_legal(move, pinned))
return move;
}
}
return MOVE_NONE;
}
-
-
-/// MovePicker::init_phase_table() initializes the PhaseTable[],
-/// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex
-/// and QsearchWithoutChecksPhaseIndex. 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;
- PhaseTable[i++] = PH_KILLERS;
- 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_TT_MOVE;
- PhaseTable[i++] = PH_QCAPTURES;
- PhaseTable[i++] = PH_QCHECKS;
- PhaseTable[i++] = PH_STOP;
-
- // Quiescence search without checks
- QsearchWithoutChecksPhaseIndex = i - 1;
- PhaseTable[i++] = PH_TT_MOVE;
- PhaseTable[i++] = PH_QCAPTURES;
- PhaseTable[i++] = PH_STOP;
-}
projects / stockfish / blobdiff