static void
bit_works_bitscanLS1B_64_test (void)
{
g_assert( 0 == bit_works_bitscanLS1B_64(0x0000000000000001));
g_assert( 4 == bit_works_bitscanLS1B_64(0x0000000000000010));
g_assert(63 == bit_works_bitscanLS1B_64(0x8000000000000000));
g_assert( 0 == bit_works_bitscanLS1B_64(0xFFFFFFFFFFFFFFFF));
g_assert( 0 == bit_works_bitscanLS1B_64(0x0000000000000003));
}
/**
* @brief Computes the legal move list structure given the set.
*
* @param [in] legal_move_set the set of legal moves
* @param [out] legal_move_list the compuetd list of legal moves
*/
inline static void
legal_move_list_from_set (const SquareSet legal_move_set,
LegalMoveList *legal_move_list)
{
legal_move_list->move_count = 0;
legal_move_list->square_set = legal_move_set;
SquareSet remaining_moves = legal_move_set;
while (remaining_moves) {
const Square move = bit_works_bitscanLS1B_64(remaining_moves);
legal_move_list->squares[legal_move_list->move_count] = move;
legal_move_list->move_count++;
remaining_moves ^= 1ULL << move;
}
return;
}
/*
* Sorts moves in ascending order of mobility.
*/
static void
sort_moves_by_mobility_count (MoveList *move_list,
const GamePosition *const gp)
{
MoveListElement *curr = NULL;
int move_index = 0;
const SquareSet moves = game_position_legal_moves(gp);
SquareSet moves_to_search = moves;
for (int i = 0; i < legal_moves_priority_cluster_count; i++) {
moves_to_search = legal_moves_priority_mask[i] & moves;
while (moves_to_search) {
curr = &move_list->elements[move_index];
const Square move = bit_works_bitscanLS1B_64(moves_to_search);
moves_to_search &= ~(1ULL << move);
GamePosition *next_gp = game_position_make_move(gp, move);
const SquareSet next_moves = game_position_legal_moves(next_gp);
game_position_free(next_gp);
const int next_move_count = bit_works_bitcount_64(next_moves);
curr->sq = move;
curr->mobility = next_move_count;
for (MoveListElement *element = move_list->head.succ; element != NULL; element = element->succ) {
if (curr->mobility < element->mobility) { /* Insert current before element. */
MoveListElement *left = element->pred;
MoveListElement *right = element;
curr->pred = left;
curr->succ = right;
left->succ = curr;
right->pred = curr;
goto out;
}
}
out:
move_index++;
}
}
return;
}
