PostgreSQL - PostGIS ST_SetValues - int array cast to double and back

I am using ST_SetValues with array defined as ARRAY[[9, 9], [9, 9]]::double precision[][]. If I store 32bit integer value in this array can I retrieve this value exactly after casting from double to integer? Or is there some limited precission for integer part of the double. I want to store "packed" RGBA into a single 32bit integer there and "unpack" single color channels after output in my app. As from documentation, double should be 64bit, so in my oppinion, this should be possible, but maybe I am missing something.