static void update_best_move_history(position_t *p, int index_of_best,
sortable_move_t* lst, int count) {
tbassert(ENABLE_TABLES, "Tables weren't enabled.\n");
int color_to_move = color_to_move_of(p);
for (int i = 0; i < count; i++) {
move_t mv = get_move(lst[i]);
ptype_t pce = ptype_mv_of(mv);
rot_t ro = rot_of(mv); // rotation
square_t fs = from_square(mv);
int ot = ORI_MASK & (ori_of(p->board[fs]) + ro);
square_t ts = to_square(mv);
int s = best_move_history[BMH(color_to_move, pce, ts, ot)];
if (index_of_best == i) {
s = s + 11200; // number will never exceed 1017
}
s = s * 0.90; // decay score over time
tbassert(s < 102000, "s = %d\n", s); // or else sorting will fail
best_move_history[BMH(color_to_move, pce, ts, ot)] = s;
}
}
// Obtain a sorted move list.
static int get_sortable_move_list(searchNode *node, sortable_move_t * move_list,
int hash_table_move) {
// number of moves in list
int num_of_moves = generate_all_opt(&(node->position), move_list, false);
color_t fake_color_to_move = color_to_move_of(&(node->position));
move_t killer_a = killer[KMT(node->ply, 0)];
move_t killer_b = killer[KMT(node->ply, 1)];
// sort special moves to the front
for (int mv_index = 0; mv_index < num_of_moves; mv_index++) {
move_t mv = get_move(move_list[mv_index]);
if (mv == hash_table_move) {
set_sort_key(&move_list[mv_index], SORT_MASK);
} else if (mv == killer_a) {
set_sort_key(&move_list[mv_index], SORT_MASK - 1);
} else if (mv == killer_b) {
set_sort_key(&move_list[mv_index], SORT_MASK - 2);
} else {
ptype_t pce = ptype_mv_of(mv);
rot_t ro = rot_of(mv); // rotation
square_t fs = from_square(mv);
int ot = ORI_MASK & (ori_of(node->position.board[fs]) + ro);
square_t ts = to_square(mv);
set_sort_key(&move_list[mv_index],
best_move_history[BMH(fake_color_to_move, pce, ts, ot)]);
}
}
return num_of_moves;
}
// Obtain a sorted move list.
static int get_sortable_move_list(searchNode *node, sortable_move_t * move_list,
int hash_table_move) {
// number of moves in list
int num_of_moves = generate_all(&(node->position), move_list, false);
color_t fake_color_to_move = color_to_move_of(&(node->position));
move_t killer_a = killer[KMT(node->ply, 0)];
move_t killer_b = killer[KMT(node->ply, 1)];
for (int mv_index = 0; mv_index < num_of_moves; mv_index++) {
move_t mv = move_list[mv_index]; // don't use get_move. assumes generate_all doesn't bungle up high bits
if (mv == hash_table_move) {
set_sort_key(&move_list[mv_index], SORT_MASK);
} else if (mv == killer_a) {
set_sort_key(&move_list[mv_index], SORT_MASK - 1);
} else if (mv == killer_b) {
set_sort_key(&move_list[mv_index], SORT_MASK - 2);
} else {
ptype_t pce = ptype_mv_of(mv);
rot_t ro = rot_of(mv); // rotation
square_t fs = from_square(mv);
int ot = ORI_MASK & (ori_of(node->position.board[fs]) + ro);
square_t ts = to_square(mv);
set_sort_key(&move_list[mv_index],
best_move_history[BMH(fake_color_to_move, pce, ts, ot)]);
}
sortable_move_t insert = move_list[mv_index];
// TODO: enable this optimization for final since node counts change
// if (insert > SORT_MASK) {
int hole = mv_index;
while (hole > 0 && insert > move_list[hole-1]) {
move_list[hole] = move_list[hole-1];
hole--;
}
move_list[hole] = insert;
// }
}
return num_of_moves;
}
