[Bug libfortran/93727] Fortran 2018: EX edit descriptor

["jvdelisle at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93727

--- Comment #5 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
I have been studying this a bit by looking at the 2023 std and functionality of
printf().
Specifically printf() provides the 'A' descriptor which can be used for float
(kind=4) and double (kind=8).  It will accept a long double (80 bit aka
kind=10). I am noticing that the results of double and long double are
identical, no extra precision visible. It is very possible I am not doing that
correctly.

I do not see anything related to quad precision floats.  I am posting this as i
think we will have to do some of our own translating byte portions of floats
ourselves. Portability may be an issue. For example IBM 360 128bit precision or
some other processor may not follow the same internal representations.

Regardless I have preliminary code for the frontend that results in calling
anew fucntion write_ex in transfer.c

I think that kind=4 and kind=8 will be fine. Any thoughts on kind=10 or kind=16
I would appreciate as I further explore this.