void search() {
int move;
int depth;
int i;
bool search_ready;
for (i = 0; i < MultiPVMax; i++){
save_multipv[SearchCurrent->multipv].mate = 0;
save_multipv[SearchCurrent->multipv].depth = 0;
save_multipv[SearchCurrent->multipv].max_depth = 0;
save_multipv[SearchCurrent->multipv].value = 0;
save_multipv[SearchCurrent->multipv].time = 0;
save_multipv[SearchCurrent->multipv].node_nb = 0;
strcpy(save_multipv[SearchCurrent->multipv].pv_string,"");
}
SearchInput->multipv = option_get_int("MultiPV")-1;
SearchCurrent->multipv = 0;
ASSERT(board_is_ok(SearchInput->board));
// opening book
if (option_get_bool("OwnBook") && !SearchInput->infinite) {
move = book_move(SearchInput->board);
if (move != MoveNone) {
// play book move
SearchBest[SearchCurrent->multipv].move = move;
SearchBest[SearchCurrent->multipv].value = 1;
SearchBest[SearchCurrent->multipv].flags = SearchExact;
SearchBest[SearchCurrent->multipv].depth = 1;
SearchBest[SearchCurrent->multipv].pv[0] = move;
SearchBest[SearchCurrent->multipv].pv[1] = MoveNone;
search_update_best();
return;
}
}
// SearchInput
gen_legal_moves(SearchInput->list,SearchInput->board);
if (LIST_SIZE(SearchInput->list) < SearchInput->multipv+1){
SearchInput->multipv = LIST_SIZE(SearchInput->list)-1;
}
if (LIST_SIZE(SearchInput->list) <= 1) {
SearchInput->depth_is_limited = true;
SearchInput->depth_limit = 4; // was 1
}
// SearchInfo
if (setjmp(SearchInfo->buf) != 0) {
ASSERT(SearchInfo->can_stop);
ASSERT(SearchBest->move!=MoveNone);
search_update_current();
return;
}
// SearchRoot
list_copy(SearchRoot->list,SearchInput->list);
// SearchCurrent
board_copy(SearchCurrent->board,SearchInput->board);
my_timer_reset(SearchCurrent->timer);
my_timer_start(SearchCurrent->timer);
// init
trans_inc_date(Trans);
sort_init();
search_full_init(SearchRoot->list,SearchCurrent->board);
// analyze game for evaluation
if (SearchCurrent->board->piece_size[White] < 3 && SearchCurrent->board->piece_size[Black] < 3){
trans_endgame = true;
}
else{
trans_endgame = false;
}
// iterative deepening
search_ready = false;
for (depth = 1; depth < DepthMax; depth++) {
for (SearchCurrent->multipv = 0; SearchCurrent->multipv <= SearchInput->multipv; SearchCurrent->multipv++){
if (DispDepthStart && SearchCurrent->multipv == 0) send("info depth %d",depth);
SearchCurrent->max_extensions = depth * 10;
SearchRoot->bad_1 = false;
SearchRoot->change = false;
board_copy(SearchCurrent->board,SearchInput->board);
if (UseShortSearch && depth <= ShortSearchDepth) {
search_full_root(SearchRoot->list,SearchCurrent->board,depth,SearchShort);
} else {
search_full_root(SearchRoot->list,SearchCurrent->board,depth,SearchNormal);
}
search_update_current();
if (DispDepthEnd && SearchCurrent->multipv == SearchInput->multipv) {
send("info depth %d seldepth %d time %.0f nodes " S64_FORMAT " nps %.0f",depth,SearchCurrent->max_depth,SearchCurrent->time*1000.0,SearchCurrent->node_nb,SearchCurrent->speed);
}
// update search info
if (depth >= 1) SearchInfo->can_stop = true;
if (depth == 1
&& LIST_SIZE(SearchRoot->list) >= 2
&& LIST_VALUE(SearchRoot->list,0) >= LIST_VALUE(SearchRoot->list,1) + EasyThreshold) {
SearchRoot->easy = true;
}
if (depth > 1) {
SearchRoot->bad_2 = SearchRoot->bad_1;
SearchRoot->bad_1 = false;
ASSERT(SearchRoot->bad_2==(SearchBest->value<=SearchRoot->last_value-BadThreshold));
}
SearchRoot->last_value = SearchBest[SearchCurrent->multipv].value;
// stop search?
if (SearchInput->depth_is_limited && SearchCurrent->multipv >= SearchInput->multipv
&& depth >= SearchInput->depth_limit) {
SearchRoot->flag = true;
}
if (SearchInput->time_is_limited
&& SearchCurrent->time * 2 >= SearchInput->time_limit_1
&& !SearchRoot->bad_2) {
SearchRoot->flag = true;
}
if (SearchInput->time_is_limited
&& SearchCurrent->time >= SearchInput->time_limit_1 * EasyRatio
&& SearchRoot->easy) {
ASSERT(!SearchRoot->bad_2);
ASSERT(!SearchRoot->change);
SearchRoot->flag = true;
}
if (SearchInput->time_is_limited
&& SearchCurrent->time >= SearchInput->time_limit_1 * EarlyRatio
&& !SearchRoot->bad_2
&& !SearchRoot->change) {
SearchRoot->flag = true;
}
if (SearchInfo->can_stop
&& (SearchInfo->stop || (SearchRoot->flag && !SearchInput->infinite))) {
search_ready = true;
break;
}
}
if (search_ready)
break;
}
}
static int full_root(list_t * list, board_t * board, int alpha, int beta, int depth, int height, int search_type) {
int old_alpha;
int value, best_value[MultiPVMax];
int i, move, j;
int new_depth;
undo_t undo[1];
mv_t new_pv[HeightMax];
bool found;
ASSERT(list_is_ok(list));
ASSERT(board_is_ok(board));
ASSERT(range_is_ok(alpha,beta));
ASSERT(depth_is_ok(depth));
ASSERT(height_is_ok(height));
ASSERT(search_type==SearchNormal||search_type==SearchShort);
ASSERT(list==SearchRoot->list);
ASSERT(!LIST_IS_EMPTY(list));
ASSERT(board==SearchCurrent->board);
ASSERT(board_is_legal(board));
ASSERT(depth>=1);
// init
SearchStack[height].best_move = MoveNone;
SearchStack[height].move = MoveNone;
SearchStack[height].threat_move = MoveNone;
SearchStack[height].reduced = false;
SearchCurrent->node_nb++;
SearchInfo->check_nb--;
if (SearchCurrent->multipv == 0)
for (i = 0; i < LIST_SIZE(list); i++) list->value[i] = ValueNone;
old_alpha = alpha;
best_value[SearchCurrent->multipv] = ValueNone;
// move loop
for (i = 0; i < LIST_SIZE(list); i++) {
move = LIST_MOVE(list,i);
if (SearchCurrent->multipv > 0){
found = false;
for (j = 0; j < SearchCurrent->multipv; j++){
if (SearchBest[j].pv[0] == move){
found = true;
break;
}
}
if (found == true)
continue;
}
SearchStack[height].move = move;
SearchRoot->depth = depth;
SearchRoot->move = move;
SearchRoot->move_pos = i;
SearchRoot->move_nb = LIST_SIZE(list);
search_update_root();
new_depth = full_new_depth(depth,move,board,board_is_check(board)&&LIST_SIZE(list)==1,false,true, height);
move_do(board,move,undo);
if (search_type == SearchShort || best_value[SearchCurrent->multipv] == ValueNone) { // first move
value = -full_search(board,-beta,-alpha,new_depth,height+1,new_pv,NodePV);
if (value <= alpha){ // research
old_alpha = -ValueInf;
value = -full_search(board,-beta,ValueInf,new_depth,height+1,new_pv,NodePV);
}
else if (value >= beta){ // research
value = -full_search(board,-ValueInf,-alpha,new_depth,height+1,new_pv,NodePV);
}
} else { // other moves
value = -full_search(board,-alpha-1,-alpha,new_depth,height+1,new_pv,NodeCut);
if (value > alpha) { // && value < beta
SearchRoot->change = true;
SearchRoot->easy = false;
SearchRoot->flag = false;
search_update_root();
value = -full_search(board,-beta,-alpha,new_depth,height+1,new_pv,NodePV);
}
}
move_undo(board,move,undo);
if (value <= alpha) { // upper bound
list->value[i] = old_alpha;
} else if (value >= beta) { // lower bound
list->value[i] = beta;
} else { // alpha < value < beta => exact value
list->value[i] = value;
}
if (value > best_value[SearchCurrent->multipv] && (best_value[SearchCurrent->multipv] == ValueNone || value > alpha)) {
SearchBest[SearchCurrent->multipv].move = move;
SearchStack[height].best_move = move;
SearchBest[SearchCurrent->multipv].value = value;
if (value <= alpha) { // upper bound
SearchBest[SearchCurrent->multipv].flags = SearchUpper;
} else if (value >= beta) { // lower bound
SearchBest[SearchCurrent->multipv].flags = SearchLower;
} else { // alpha < value < beta => exact value
SearchBest[SearchCurrent->multipv].flags = SearchExact;
}
SearchBest[SearchCurrent->multipv].depth = depth;
pv_cat(SearchBest[SearchCurrent->multipv].pv,new_pv,move);
search_update_best();
}
if (value > best_value[SearchCurrent->multipv]) {
best_value[SearchCurrent->multipv] = value;
if (value > alpha) {
if (search_type == SearchNormal) alpha = value;
if (value >= beta) break;
}
}
}
ASSERT(value_is_ok(best_value));
list_sort(list);
ASSERT(SearchBest->move==LIST_MOVE(list,0));
ASSERT(SearchBest->value==best_value);
if (UseTrans && best_value[SearchCurrent->multipv] > old_alpha && best_value[SearchCurrent->multipv] < beta) {
pv_fill(SearchBest[SearchCurrent->multipv].pv,board);
}
return best_value[SearchCurrent->multipv];
}
