PTN_SET_BRANCH_POSITION
PTN_SET_BRANCH_POSITION(PT_NODE(node), position);
PTN_SET_BRANCH_POSITION(dst, PTN_BRANCH_POSITION(src));
PTN_SET_BRANCH_POSITION(mask, id->id_parent_slot);
PTN_SET_BRANCH_POSITION(target, id->id_parent_slot);
PTN_SET_BRANCH_POSITION(target, id->id_parent_slot);
PTN_SET_BRANCH_POSITION(parent, PTN_BRANCH_POSITION(target));