[Bug fortran/95640] gfortran ieee_selected_real_kind returns 10

[sgk at troutmask dot apl.washington.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95640

--- Comment #15 from Steve Kargl <sgk at troutmask dot apl.washington.edu> ---
On Fri, Jun 12, 2020 at 03:33:20PM +0000, anlauf at gcc dot gnu.org wrote:
> --- Comment #14 from anlauf at gcc dot gnu.org ---
> Why don't we simply set IEEE_SUPPORT_DATATYPE (1._10) to .false.?
> 
> use, intrinsic :: ieee_arithmetic
> print *, ieee_support_datatype (1._10)
> end
> 
> We currently print 'T'.
> 

Because REAL(10) is a valid IEEE-754 format.  Some may want
REAL(10) because it is sufficient for their numerical problem
and it is done in hardware.  REAL(16) is a software implementation
(can you say slow).