I'm having a hard time getting a straight answer about long double precision on ARM64 architecture. I'm engineering a scientific machine requiring extreme precision, and the driver, which I will write in c++, must keep rounding errors to a minumum. I'll probably use a pi 3B+ for the prototype and some sort of ARM64 architecture for the finished product, but I'm concerned about rounding errors.
I have two questions. First, is the long double supported natively in g++ on the pi with the same precision of x86_64 machines? Second, if it is not, how can I use more digits in my calculations on ARM64 architecture? I'm not averse to linking libraries.