Re: in gfortran, is it faster compile times with *.mod files ?

Lynn McGuire <lynnmcguire5@gmail.com> schrieb:

On 11/11/2024 4:01 PM, Thomas Koenig wrote:

Lynn McGuire <lynnmcguire5@gmail.com> schrieb:

In gfortran, is it faster compile times with *.mod files ?  Or is it
just as fast compiling to include the module interface information in
each subroutine / function file ?

 
I haven't benchmarked this, but I think likely that there would only
be a small difference.  Usually, the front end only takes a small part of
compilation time (but there are pathological cases).
 
In general, modules are better because of automatic checking.
If you want to avoid recompilation cascades, submodules (where
you can separate the definition from the implementation) might
be worth looking into.
 

Is there any chance that gfortran will automatically generate and use
module files in the future like IVF ?

 
Not sure what you're asking for.  Can you give an example?

>
1. you compile abc.f in IVF
2. IVF automagically creates an abc__genmod.f90 file in your release
subdirectory with the subroutine / function module interface in it

I think I get the general gist (but it would help me understand
if you could post a complete example).

But gfortran currently does not have such a feature (which appears
to duplicate modules).  It is also not immediately clear what should
happen if, for example, a procedure uses a derived type from another
module... (This may not be relevant to your case, but as a compiler
writer, you have to think about this kind of thing :-|)

What would go wrong if you simply encapsulated abc.f in

      MODULE ABC
      CONTAINS
C  Your code here
      END MODULE ABC

?