compile cube extension with float4 precision storing

Is it possible to make cube extension with float(4bytes) precision instead
of double(8bytes)?

I use cube extension for storing embedding vectors and calculation distance
on them. During comparing vectors, a 4byte float precision is enough.
Storing 8 byte double precision is wasting disk space.

Now to avoid disk wasting I store vectors as real[] array and create cube
objects on the fly. But this solution is wasting cpu time

--

Siarhei Damanau