F95 supports F77 too, right? (was Re: GCC 4.0 vs. 3.5

[Paul Brook]

On Saturday 17 April 2004 15:41, Daniel Jacobowitz wrote:
> On Sat, Apr 17, 2004 at 09:46:31AM -0400, Nathanael Nerode wrote:
> > Geert Bosch wrote:
> > >The reality is that many things change. New languages are added
> > >(Fortran 95), others are dropped (Fortran 77, maybe Ada temporarily).
> >
> > I was under the impression that the new Fortran compiler was fully
> > functional as a Fortran 77 compiler, or at least that it was supposed to
> > be before g77 was removed from the tree.  Was I mistaken?

g77 was removed from the tree because it doesn't work with function-at-time, 
the same reason Ada is currently disabled.
It would take a large amount of effort to make g77 work with function at a 
time. This will probably never happen as such effort is better spent 
improving gfortran.

> Disclaimer: I know very little Fortran and very little about Fortran.
> I just play a mailing list junkie on TV.
>
> There's a difference between fully functional Fortran 77 compiler and a
> fully functional g77 replacement; Fortran 77 appears to be a frequently
> extended language.  

Correct. 

> I believe that g95 is planned to support Fortran 
> 77, but not necessarily all of the other gunk supported by g77.

We hope to support most, if not all, of the "gunk" supported by g77. However 
it's unlikely that this will happen in time for 3.5.

It's also worth noting that we're still concentrating on features/completeness 
rather than performance for gfortran. We've had mixed reports so far, and 
gfortran may initially generate worse code than g77.

Paul