Re: fortran standard

[Matt Newville <newville@cars.uchicago.edu>]

On Sun, 11 Mar 2001, John J. Rehr wrote:

>   For example, with Matt's proposed standard below, I would not be
> at all surprised if FEFF compiled on all of them and failed on
> the picky AIX compiler.
>
> > I agree: standards are good, but 25-year-old standards for computer
> > languages may be ready for retirement.  My view is that g77 and f2c
> > have replaced the ANSI-F77 standard.  I'd propose this definition of
> > a 'Standard Fortran' Guidelines for Feff. Can FEFF be compiled with
> >      IRIX f77
> >      g77 on linux
> >      f2c/cc on at least one system.
> >      Compaq Digital Fortran (v5 or higher) on Win32
> >      Absoft compiler on Mac
>
>    Thus I'd like to augment Matt's list to include pgf77, AIX, CRAY cf77,
> VAX fortran and the hp f90. Anything else out there that I missed?
>
>    The bottom line, is that FEFF should be portable to virtually
> any modern machine (I don't think we have to support relics), i.e.,
> to compile and run (preferably even without warnings).  Sometimes FEFF
> finds real compiler bugs, but we have usually recoded to make the code work
> anyway.

I agree:  'portable to virtually any modern machine', though I
wouldn't necessarily say 'ported'.  I do remember AIX's xlf as being
particularly nasty, but haven't used one in years.

One approach to finding what machines to target might be to ask Feff
users what they actually use.  GNXAS sent out such a survey sometime
last year, and reported these results for 'what machines should
GNXAS consider supporting':

    Interest in using GNXAS on platform (multi-answer allowed):
                                 share          global share
    Linux                   33   (45.2%)        66 %
    UNIX DIGITAL            12   (16.4%)        24 %
    OpenVMS                  9   (12.3%)        18 %
    UNIX HP                  6   (8.3%)         12 %
    UNIX SGI                 6   (8.3%)         12 %
    UNIX SUN                 3   (4.1%)          6 %
    Macintosh                2   (2.7%)          4 %
    Windows                  2   (2.7%)          4 %
    ------------------------------------------------
                            73 different platforms selected

I believe GNXAS ran soley on VMS/DigitalUnix for years, and
apparently I personally know half the people who checked 'Windows'
and 'Mac' on this survey. :).  I'd guess Feff to be more heavily
skewed towards Windows, Mac, SGI, and Sun, but a survey would be the
real way to find out.

--Matt Newville

|= Matthew Newville        email: newville@cars.uchicago.edu
|= GSECARS, Bldg 434A      voice: (630) 252-0431
|= Argonne Natl Lab        fax:   (630) 252-0443
|= 9700 South Cass Ave     http://cars.uchicago.edu/~newville/
|= Argonne, IL 60439 USA