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Restore original movepick modulo space inflation 

We have a regression somewhere here so restart from zero
and proceed one change at a time.

With this modification we have the same strenght of
"Introduce Stockfish" patch that is our strongest to date.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
sf_2.3.1_base
Marco Costalba 2008-10-25 15:28:24 +01:00
parent 5dd9159106
commit f8bc38a006
2 changed files with 146 additions and 122 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

257
src/movepick.cpp
View File

@ -7,12 +7,12 @@
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.
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 <http://www.gnu.org/licenses/>.
*/
@ -61,8 +61,9 @@ namespace {
/// search captures, promotions and some checks) and about how important good
/// move ordering is at the current node.
MovePicker::MovePicker(const Position& p, bool pvnode, Move ttm, Move mk,
Move k1, Move k2, Depth d) : pos(p) {
MovePicker::MovePicker(Position& p, bool pvnode, Move ttm, Move mk,
Move k1, Move k2, Depth d) {
pos = &p;
pvNode = pvnode;
ttMove = ttm;
mateKiller = (mk == ttm)? MOVE_NONE : mk;
@ -111,13 +112,16 @@ Move MovePicker::get_next_move() {
// Next phase
phaseIndex++;
switch (PhaseTable[phaseIndex]) {
case PH_TT_MOVE:
if (ttMove != MOVE_NONE)
{
assert(move_is_ok(ttMove));
if (generate_move_if_legal(pos, ttMove, pinned) != MOVE_NONE)
return ttMove;
Move m = generate_move_if_legal(*pos, ttMove, pinned);
if (m != MOVE_NONE)
{
assert(m == ttMove);
return m;
}
}
break;
@ -125,13 +129,17 @@ Move MovePicker::get_next_move() {
if (mateKiller != MOVE_NONE)
{
assert(move_is_ok(mateKiller));
if (generate_move_if_legal(pos, mateKiller, pinned) != MOVE_NONE)
return mateKiller;
}
break;
Move m = generate_move_if_legal(*pos, mateKiller, pinned);
if (m != MOVE_NONE)
{
assert(m == mateKiller);
return m;
}
}
break;
case PH_GOOD_CAPTURES:
numOfMoves = generate_captures(pos, moves);
case PH_GOOD_CAPTURES:
numOfMoves = generate_captures(*pos, moves);
score_captures();
movesPicked = 0;
break;
@ -141,26 +149,26 @@ Move MovePicker::get_next_move() {
break;
case PH_NONCAPTURES:
numOfMoves = generate_noncaptures(pos, moves);
numOfMoves = generate_noncaptures(*pos, moves);
score_noncaptures();
movesPicked = 0;
break;
case PH_EVASIONS:
assert(pos.is_check());
numOfMoves = generate_evasions(pos, moves);
assert(pos->is_check());
numOfMoves = generate_evasions(*pos, moves);
score_evasions();
movesPicked = 0;
break;
case PH_QCAPTURES:
numOfMoves = generate_captures(pos, moves);
numOfMoves = generate_captures(*pos, moves);
score_qcaptures();
movesPicked = 0;
break;
case PH_QCHECKS:
numOfMoves = generate_checks(pos, moves, dc);
numOfMoves = generate_checks(*pos, moves, dc);
movesPicked = 0;
break;
@ -173,7 +181,6 @@ Move MovePicker::get_next_move() {
}
}
assert(false);
return MOVE_NONE;
}
@ -183,27 +190,30 @@ Move MovePicker::get_next_move() {
Move MovePicker::get_next_move(Lock &lock) {
lock_grab(&lock);
if (finished)
{
lock_release(&lock);
return MOVE_NONE;
}
Move m = get_next_move();
if (m == MOVE_NONE)
finished = true;
Move m;
lock_release(&lock);
return m;
lock_grab(&lock);
if (finished)
{
lock_release(&lock);
return MOVE_NONE;
}
m = get_next_move();
if (m == MOVE_NONE)
finished = true;
lock_release(&lock);
return m;
}
/// 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 pick_move_from_list().
void MovePicker::score_captures() {
// Winning and equal captures in the main search are ordered by MVV.
// 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
@ -214,11 +224,16 @@ void MovePicker::score_captures() {
// the subtree size.
for (int i = 0; i < numOfMoves; i++)
{
Move m = moves[i].move;
moves[i].score = pos.see(m);
if (moves[i].score >= 0)
moves[i].score = move_promotion(m) ? QueenValueMidgame
: pos.midgame_value_of_piece_on(move_to(m));
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;
}
}
@ -232,13 +247,7 @@ void MovePicker::score_noncaptures() {
else if (m == killer2)
moves[i].score = HistoryMax + 1;
else
moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), m);
// Ensure moves in history are always sorted as first
if (moves[i].score > 0)
moves[i].score += 1000;
moves[i].score += pos.mg_pst_delta(moves[i].move);
moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m);
}
}
@ -249,47 +258,31 @@ void MovePicker::score_evasions() {
Move m = moves[i].move;
if (m == ttMove)
moves[i].score = 2*HistoryMax;
else if (!pos.square_is_empty(move_to(m)))
else if(!pos->square_is_empty(move_to(m)))
{
moves[i].score = pos.see(m);
if (moves[i].score >= 0)
moves[i].score += HistoryMax;
}
else
moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), 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);
}
// FIXME try psqt also here
}
void MovePicker::score_qcaptures() {
// Use MVV ordering
// Use MVV/LVA ordering
for (int i = 0; i < numOfMoves; i++)
{
Move m = moves[i].move;
moves[i].score = move_promotion(m) ? QueenValueMidgame
: pos.midgame_value_of_piece_on(move_to(m));
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;
}
}
/// find_best_index() loops across the moves and returns index of
/// the highest scored one.
int MovePicker::find_best_index() {
int bestScore = -10000000, bestIndex = -1;
for (int i = movesPicked; i < numOfMoves; i++)
if (moves[i].score > bestScore)
{
bestIndex = i;
bestScore = moves[i].score;
}
return bestIndex;
}
/// 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
@ -300,17 +293,18 @@ int MovePicker::find_best_index() {
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(!pos->is_check());
assert(movesPicked >= 0);
while (movesPicked < numOfMoves)
{
int bestScore = -10000000;
bestScore = -10000000;
bestIndex = -1;
for (int i = movesPicked; i < numOfMoves; i++)
{
@ -320,66 +314,87 @@ Move MovePicker::pick_move_from_list() {
assert(numOfBadCaptures < 63);
badCaptures[numOfBadCaptures++] = moves[i];
moves[i--] = moves[--numOfMoves];
}
else if (moves[i].score > bestScore)
{
bestIndex = i;
bestScore = moves[i].score;
}
}
else if (moves[i].score > bestScore)
{
bestIndex = i;
bestScore = moves[i].score;
}
}
if (bestIndex != -1) // Found a good capture
{
move = moves[bestIndex].move;
move = moves[bestIndex].move;
moves[bestIndex] = moves[movesPicked++];
if ( move != ttMove
&& move != mateKiller
&& pos.move_is_legal(move, pinned))
&& pos->move_is_legal(move, pinned))
return move;
}
}
break;
case PH_NONCAPTURES:
assert(!pos.is_check());
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.
bestIndex = (movesPicked < 12 || pvNode ? find_best_index() : movesPicked);
if (pvNode || movesPicked < 12)
{
bestIndex = -1;
for (int i = movesPicked; i < numOfMoves; i++)
if (moves[i].score > bestScore)
{
bestIndex = i;
bestScore = moves[i].score;
}
} else
bestIndex = movesPicked;
if (bestIndex != -1)
{
move = moves[bestIndex].move;
move = moves[bestIndex].move;
moves[bestIndex] = moves[movesPicked++];
if ( move != ttMove
&& move != mateKiller
&& pos.move_is_legal(move, pinned))
&& pos->move_is_legal(move, pinned))
return move;
}
}
break;
case PH_EVASIONS:
assert(pos.is_check());
assert(movesPicked >= 0);
while (movesPicked < numOfMoves)
{
bestIndex = find_best_index();
if (bestIndex != -1)
{
move = moves[bestIndex].move;
moves[bestIndex] = moves[movesPicked++];
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)
{
move = moves[bestIndex].move;
moves[bestIndex] = moves[movesPicked++];
return move;
}
}
break;
case PH_BAD_CAPTURES:
assert(!pos.is_check());
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
@ -388,38 +403,51 @@ Move MovePicker::pick_move_from_list() {
move = badCaptures[badCapturesPicked++].move;
if ( move != ttMove
&& move != mateKiller
&& pos.move_is_legal(move, pinned))
&& pos->move_is_legal(move, pinned))
return move;
}
break;
case PH_QCAPTURES:
assert(!pos.is_check());
assert(!pos->is_check());
assert(movesPicked >= 0);
while (movesPicked < numOfMoves)
{
// FIXME makes sens to score qcaps?
bestIndex = (movesPicked < 4 ? find_best_index() : movesPicked);
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;
}
} else
bestIndex = movesPicked;
if (bestIndex != -1)
{
move = moves[bestIndex].move;
move = moves[bestIndex].move;
moves[bestIndex] = moves[movesPicked++];
if (move != ttMove && pos.move_is_legal(move, pinned))
// 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;
}
}
break;
case PH_QCHECKS:
assert(!pos.is_check());
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;
if (move != ttMove && pos.move_is_legal(move, pinned))
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;
@ -430,19 +458,14 @@ Move MovePicker::pick_move_from_list() {
return MOVE_NONE;
}
/// MovePicker::current_move_type() returns the type of the just
/// picked next move. It can be used in search to further differentiate
/// according to the current move type: capture, non capture, escape, etc.
MovePicker::MovegenPhase MovePicker::current_move_type() const {
return PhaseTable[phaseIndex];
}
/// MovePicker::init_phase_table() initializes the PhaseTable[],
/// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex
/// and QsearchWithoutChecksPhaseIndex variables. It is only called once
/// and QsearchWithoutChecksPhaseIndex variables. It is only called once
/// during program startup, and never again while the program is running.
void MovePicker::init_phase_table() {

11
src/movepick.h
View File

@ -2,12 +2,12 @@
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008 Marco Costalba
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.
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
@ -60,7 +60,8 @@ public:
PH_STOP
};
MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, Depth d);
MovePicker(Position &p, bool pvnode, Move ttm, Move mk, Move k1, Move k2,
Depth dpth);
Move get_next_move();
Move get_next_move(Lock &lock);
int number_of_moves() const;
@ -76,9 +77,8 @@ private:
void score_evasions();
void score_qcaptures();
Move pick_move_from_list();
int find_best_index();
const Position& pos;
Position *pos;
Move ttMove, mateKiller, killer1, killer2;
Bitboard pinned, dc;
MoveStack moves[256], badCaptures[64];
@ -101,6 +101,7 @@ private:
/// a single reply to check.
inline int MovePicker::number_of_moves() const {
return numOfMoves;
}