Bit manipulation question

[Bartholomew Simpson]

I need to pack two small values (each of which requires less 16 bit
storage), in a double data type.

Can anyone suggesthow I may implement the ff funcs to retrive/store
values in the double ?

void store_lowword(double storage, const float value);
float get_lowword(const double storage);
void store_highword(double storage, const float value) ;
float get_highword(const double storage);