/* Choose the best move (by searching or using the book), and make it. */
static void
cpu_move(Chess *chess)
{
bool book_used = false;
char san_move[MAX_BUF];
char str_move[MAX_BUF];
U32 move = NULLMOVE;
int score = 0;
S64 timer;
Board *board;
ASSERT(1, chess != NULL);
board = &chess->board;
timer = get_ms();
chess->sd.cmd_type = CMDT_CONTINUE;
if (settings.book_type != BOOK_OFF)
move = get_book_move(board, chess->show_pv, chess->book);
if (move != NULLMOVE) {
book_used = true;
chess->in_book = true;
} else {
score = id_search(chess, NULLMOVE);
if (chess->sd.cmd_type == CMDT_CANCEL) {
chess->cpu_color = COLOR_NONE;
return;
}
move = chess->sd.move;
chess->in_book = false;
}
timer = get_ms() - timer;
ASSERT(1, move != NULLMOVE);
move_to_str(move, str_move);
if (SIGN(board->color)*score < VAL_RESIGN) {
if (board->color == WHITE)
printf("0-1 {White resigns}\n");
else
printf("1-0 {Black resigns}\n");
chess->game_over = true;
return;
}
printf("move %s\n", str_move);
if (chess->debug && chess->sd.nnodes > 0) {
print_search_data(&chess->sd, (int)timer);
printf("Score: %d\n", score);
}
move_to_san(san_move, board, move);
update_game_log(board, san_move, score, book_used);
update_game(chess, move);
}
int
extended_compute_move( int side_to_move, int book_only,
int book, int mid, int exact, int wld ) {
int i, j;
int index;
int changed;
int this_move;
int disc_diff, corrected_diff;
int best_move, temp_move;
int best_score;
int best_pv_depth;
int stored_echo;
int shallow_eval;
int empties;
int current_mid, current_exact, current_wld;
int first_iteration;
int unsearched;
int unsearched_count;
int unsearched_move[61];
int best_pv[60];
unsigned int transform1[60], transform2[60];
CandidateMove book_move;
EvaluatedMove temp;
EvaluationType book_eval_info;
EvalResult res;
/* Disable all time control mechanisms and randomization */
toggle_abort_check( FALSE );
toggle_midgame_abort_check( FALSE );
toggle_perturbation_usage( FALSE );
start_move( 0, 0, disc_count( BLACKSQ ) + disc_count( WHITESQ ) );
clear_ponder_times();
determine_hash_values( side_to_move, board );
empties = 60 - disks_played;
best_move = 0;
game_evaluated_count = 0;
reset_counter( &nodes );
generate_all( side_to_move );
if ( book_only || book ) { /* Evaluations for database moves */
int flags = 0;
if ( empties <= exact )
flags = FULL_SOLVED;
else if ( empties <= wld )
flags = WLD_SOLVED;
fill_move_alternatives( side_to_move, flags );
game_evaluated_count = get_candidate_count();
for ( i = 0; i < game_evaluated_count; i++ ) {
int child_flags;
book_move = get_candidate( i );
evaluated_list[i].side_to_move = side_to_move;
evaluated_list[i].move = book_move.move;
evaluated_list[i].pv_depth = 1;
evaluated_list[i].pv[0] = book_move.move;
evaluated_list[i].eval =
create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
book_move.score, 0.0, 0, TRUE );
child_flags = book_move.flags & book_move.parent_flags;
if ( child_flags & (FULL_SOLVED | WLD_SOLVED) ) {
if ( child_flags & FULL_SOLVED )
evaluated_list[i].eval.type = EXACT_EVAL;
else
evaluated_list[i].eval.type = WLD_EVAL;
if ( book_move.score > 0 ) {
evaluated_list[i].eval.res = WON_POSITION;
/* Normalize the scores so that e.g. 33-31 becomes +256 */
evaluated_list[i].eval.score -= CONFIRMED_WIN;
evaluated_list[i].eval.score *= 128;
}
else if ( book_move.score == 0 )
evaluated_list[i].eval.res = DRAWN_POSITION;
else { /* score < 0 */
evaluated_list[i].eval.res = LOST_POSITION;
/* Normalize the scores so that e.g. 30-34 becomes -512 */
evaluated_list[i].eval.score += CONFIRMED_WIN;
evaluated_list[i].eval.score *= 128;
}
}
else
evaluated_list[i].eval.type = MIDGAME_EVAL;
}
}
if ( book_only ) { /* Only book moves are to be considered */
if ( game_evaluated_count > 0 ) {
best_move = get_book_move( side_to_move, FALSE, &book_eval_info );
set_current_eval( book_eval_info );
}
else {
pv_depth[0] = 0;
best_move = PASS;
book_eval_info = create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
0, 0.0, 0, FALSE );
set_current_eval( book_eval_info );
}
}
else { /* Make searches for moves not in the database */
int shallow_depth;
int empties = 60 - disks_played;
book = FALSE;
best_score = -INFINITE_EVAL;
if ( game_evaluated_count > 0 ) { /* Book PV available */
best_score = evaluated_list[0].eval.score;
best_move = evaluated_list[0].move;
}
negate_current_eval( TRUE );
/* Store the available moves, clear their evaluations and sort
them on shallow evaluation. */
if ( empties < 12 )
shallow_depth = 1;
else {
int max_depth = MAX( mid, MAX( exact, wld ) );
if ( max_depth >= 16 )
shallow_depth = 6;
else
shallow_depth = 4;
}
unsearched_count = 0;
for ( i = 0; i < move_count[disks_played]; i++ ) {
this_move = move_list[disks_played][i];
unsearched = TRUE;
for ( j = 0; j < game_evaluated_count; j++ )
if ( evaluated_list[j].move == this_move )
unsearched = FALSE;
if ( !unsearched )
continue;
unsearched_move[unsearched_count] = this_move;
unsearched_count++;
(void) make_move( side_to_move, this_move, TRUE );
if ( shallow_depth == 1 ) /* Compute move doesn't allow depth 0 */
shallow_eval = -static_evaluation( OPP( side_to_move ) );
else {
EvaluationType shallow_info;
(void) compute_move( OPP( side_to_move ), FALSE, 0, 0, FALSE, book,
shallow_depth - 1, 0, 0, TRUE, &shallow_info );
if ( shallow_info.type == PASS_EVAL ) {
/* Don't allow pass */
(void) compute_move( side_to_move, FALSE, 0, 0, FALSE, book,
shallow_depth - 1, 0, 0, TRUE, &shallow_info );
if ( shallow_info.type == PASS_EVAL ) { /* Game over */
disc_diff =
disc_count( side_to_move ) - disc_count( OPP( side_to_move ) );
if ( disc_diff > 0 )
corrected_diff = 64 - 2 * disc_count( OPP( side_to_move) );
else if ( disc_diff == 0 )
corrected_diff = 0;
else
corrected_diff = 2 * disc_count( side_to_move ) - 64;
shallow_eval = 128 * corrected_diff;
}
else
shallow_eval = shallow_info.score;
}
else /* Sign-correct the score produced */
shallow_eval = -shallow_info.score;
}
unmake_move( side_to_move, this_move );
evals[disks_played][this_move] = shallow_eval;
}
do {
changed = FALSE;
for ( i = 0; i < unsearched_count - 1; i++ )
if ( evals[disks_played][unsearched_move[i]] <
evals[disks_played][unsearched_move[i + 1]] ) {
temp_move = unsearched_move[i];
unsearched_move[i] = unsearched_move[i + 1];
unsearched_move[i + 1] = temp_move;
changed = TRUE;
}
} while ( changed );
/* Initialize the entire list as being empty */
for ( i = 0, index = game_evaluated_count; i < unsearched_count;
i++, index++ ) {
evaluated_list[index].side_to_move = side_to_move;
evaluated_list[index].move = unsearched_move[i];
evaluated_list[index].eval =
create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
0, 0.0, 0, FALSE );
evaluated_list[index].pv_depth = 1;
evaluated_list[index].pv[0] = unsearched_move[i];
if ( empties > MAX( wld, exact ) ) {
transform1[i] = abs( my_random() );
transform2[i] = abs( my_random() );
}
else {
transform1[i] = 0;
transform2[i] = 0;
}
}
stored_echo = echo;
echo = FALSE;
best_pv_depth = 0;
if ( mid == 1 ) { /* compute_move won't be called */
pv_depth[0] = 0;
piece_count[BLACKSQ][disks_played] = disc_count( BLACKSQ );
piece_count[WHITESQ][disks_played] = disc_count( WHITESQ );
}
/* Perform iterative deepening if the search depth is large enough */
#define ID_STEP 2
if ( exact > empties )
exact = empties;
if ( (exact < 12) || (empties > exact) )
current_exact = exact;
else
current_exact = (8 + (exact % 2)) - ID_STEP;
if ( wld > empties )
wld = empties;
if ( (wld < 14) || (empties > wld) )
current_wld = wld;
else
current_wld = (10 + (wld % 2)) - ID_STEP;
if ( ((empties == exact) || (empties == wld)) &&
(empties > 16) && (mid < empties - 12) )
mid = empties - 12;
if ( mid < 10 )
current_mid = mid;
else
current_mid = (6 + (mid % 2)) - ID_STEP;
first_iteration = TRUE;
do {
if ( current_mid < mid ) {
current_mid += ID_STEP;
/* Avoid performing deep midgame searches if the endgame
is reached anyway. */
if ( (empties <= wld) && (current_mid + 7 >= empties) ) {
current_wld = wld;
current_mid = mid;
}
if ( (empties <= exact) && (current_mid + 7 >= empties) ) {
current_exact = exact;
current_mid = mid;
}
}
else if ( current_wld < wld )
current_wld = wld;
else
current_exact = exact;
for ( i = 0; (i < unsearched_count) && !force_return; i++ ) {
EvaluationType this_eval;
this_move = unsearched_move[i];
/* Locate the current move in the list. This has to be done
because the moves might have been reordered during the
iterative deepening. */
index = 0;
while ( evaluated_list[index].move != this_move )
index++;
/* To avoid strange effects when browsing back and forth through
a game during the midgame, rehash the hash transformation masks
for each move unless the endgame is reached */
set_hash_transformation( transform1[i], transform2[i] );
/* Determine the score for the ith move */
prefix_move = this_move;
(void) make_move( side_to_move, this_move, TRUE );
if ( current_mid == 1 ) {
/* compute_move doesn't like 0-ply searches */
shallow_eval = static_evaluation( OPP( side_to_move ) );
this_eval =
create_eval_info( MIDGAME_EVAL, UNSOLVED_POSITION,
shallow_eval, 0.0, 0, FALSE );
}
else
(void) compute_move( OPP( side_to_move ), FALSE, 0, 0, FALSE, book,
current_mid - 1, current_exact - 1,
current_wld - 1, TRUE,
&this_eval );
if ( force_return ) { /* Clear eval and exit search immediately */
this_eval =
create_eval_info( UNDEFINED_EVAL, UNSOLVED_POSITION,
0, 0.0, 0, FALSE );
unmake_move( side_to_move, this_move );
break;
}
if ( this_eval.type == PASS_EVAL ) {
/* Don't allow pass */
if ( current_mid == 1 ) {
/* compute_move doesn't like 0-ply searches */
shallow_eval = static_evaluation( side_to_move );
this_eval =
create_eval_info( MIDGAME_EVAL, UNSOLVED_POSITION,
shallow_eval, 0.0, 0, FALSE );
}
else
(void) compute_move( side_to_move, FALSE, 0, 0, FALSE, book,
current_mid - 1, current_exact - 1,
current_wld - 1, TRUE,
&this_eval );
if ( this_eval.type == PASS_EVAL ) { /* Game over */
disc_diff =
disc_count( side_to_move ) - disc_count( OPP( side_to_move ) );
if ( disc_diff > 0 ) {
corrected_diff = 64 - 2 * disc_count( OPP( side_to_move) );
res = WON_POSITION;
}
else if ( disc_diff == 0 ) {
corrected_diff = 0;
res = DRAWN_POSITION;
}
else {
corrected_diff = 2 * disc_count( side_to_move ) - 64;
res = LOST_POSITION;
}
this_eval =
create_eval_info( EXACT_EVAL, res, 128 * corrected_diff,
0.0, 60 - disks_played, FALSE );
}
}
else { /* Sign-correct the score produced */
this_eval.score =
-this_eval.score;
if ( this_eval.res == WON_POSITION )
this_eval.res = LOST_POSITION;
else if ( this_eval.res == LOST_POSITION )
this_eval.res = WON_POSITION;
}
if ( force_return )
break;
else
evaluated_list[index].eval = this_eval;
/* Store the PV corresponding to the move */
evaluated_list[index].pv_depth = pv_depth[0] + 1;
evaluated_list[index].pv[0] = this_move;
for ( j = 0; j < pv_depth[0]; j++ )
evaluated_list[index].pv[j + 1] = pv[0][j];
/* Store the PV corresponding to the best move */
if ( evaluated_list[index].eval.score > best_score ) {
best_score = evaluated_list[index].eval.score;
best_move = this_move;
best_pv_depth = pv_depth[0];
for ( j = 0; j < best_pv_depth; j++ )
best_pv[j] = pv[0][j];
}
unmake_move( side_to_move, this_move );
/* Sort the moves evaluated */
if ( first_iteration )
game_evaluated_count++;
if ( !force_return )
do {
changed = FALSE;
for ( j = 0; j < game_evaluated_count - 1; j++ )
if ( compare_eval( evaluated_list[j].eval,
evaluated_list[j + 1].eval ) < 0 ) {
changed = TRUE;
temp = evaluated_list[j];
evaluated_list[j] = evaluated_list[j + 1];
evaluated_list[j + 1] = temp;
}
} while ( changed );
display_status(stdout, FALSE);
}
first_iteration = FALSE;
/* Reorder the moves after each iteration. Each move is moved to
the front of the list, starting with the bad moves and ending
with the best move. This ensures that unsearched_move will be
sorted w.r.t. the order in evaluated_list. */
for ( i = game_evaluated_count - 1; i >= 0; i-- ) {
int this_move = evaluated_list[i].move;
j = 0;
while ( (j != unsearched_count) && (unsearched_move[j] != this_move) )
j++;
if ( j == unsearched_count ) /* Must be book move, skip */
continue;
/* Move the move to the front of the list. */
while ( j >= 1 ) {
unsearched_move[j] = unsearched_move[j - 1];
j--;
}
unsearched_move[0] = this_move;
}
} while ( !force_return &&
((current_mid != mid) ||
(current_exact != exact) || (current_wld != wld)) );
echo = stored_echo;
game_evaluated_count = move_count[disks_played];
/* Make sure that the PV and the score correspond to the best move */
pv_depth[0] = best_pv_depth + 1;
pv[0][0] = best_move;
for ( i = 0; i < best_pv_depth; i++ )
pv[0][i + 1] = best_pv[i];
negate_current_eval( FALSE );
if ( move_count[disks_played] > 0 )
set_current_eval( evaluated_list[0].eval );
}
/* Reset the hash transformation masks prior to leaving */
set_hash_transformation( 0, 0 );
/* Don't forget to enable the time control mechanisms when leaving */
toggle_abort_check( TRUE );
toggle_midgame_abort_check( TRUE );
toggle_perturbation_usage( TRUE );
max_depth_reached++;
prefix_move = 0;
return best_move;
}
