[R-pkg-devel] Modernizing legacy Fortran:, REAL(kind=8)

[Ivan Krylov]

On Wed, 30 Aug 2023 08:43:04 +0200
Thomas Petzoldt <thomas.petzoldt using tu-dresden.de> wrote:

> a) change REAL(kind=8) back to DOUBLE PRECISION that is again old
> style. It seems to be portable and is still widely used.

I don't have a reference as good as the Fortran standard, but Steve
Lionel said in Dr. Fortran [*] that DOUBLE PRECISION is still part of
the standard fixed-form syntax.

>  COMPLEX(KIND=8)

This could be particularly problematic if you're trying to interoperate
with C, but will probably not surface unless you use LTO:
https://bugs.r-project.org/show_bug.cgi?id=18430

Unfortunately, there's no standard DOUBLE COMPLEX.

-- 
Best regards,
Ivan

[*]
https://stevelionel.com/drfortran/2017/03/27/doctor-fortran-in-it-takes-all-kinds/