foreach_list(predecessor_node, &block->parents) {
bblock_link *predecessor_link =
(bblock_link *)predecessor_node;
bblock_t *predecessor_block = predecessor_link->block;
foreach_list(predecessor_node, &block->parents) {
bblock_link *predecessor_link =
(bblock_link *)predecessor_node;
bblock_t *predecessor_block = predecessor_link->block;