PTN_BRANCH_ROOT_SLOT
PTN_BRANCH_ROOT_SLOT(mask) = target_node;
PTN_BRANCH_ROOT_SLOT(&pt->pt_rootnode) = PTN_LEAF(target);
id.id_insertp = &PTN_BRANCH_ROOT_SLOT(id.id_parent);
if (PT_NULL_P(PTN_BRANCH_ROOT_SLOT(&pt->pt_rootnode)))
node = PTN_BRANCH_ROOT_SLOT(&pt->pt_rootnode);
next_node = PTN_BRANCH_ROOT_SLOT(ptn);
if (PT_NULL_P(PTN_BRANCH_ROOT_SLOT(&pt->pt_rootnode))) {
KASSERT(!PT_NULL_P(PTN_BRANCH_ROOT_SLOT(&pt->pt_rootnode)));
PTN_BRANCH_ROOT_SLOT(ptn);
PTN_BRANCH_ROOT_SLOT(&pt->pt_rootnode) = PT_NULL;