Re: Problem of gfortran compilation with -O option

[Tobias Burnus <burnus at net-b dot de>]

PERRONNET Alain wrote:
> My program and subroutines are mainly written in fortran 77 with blanck
> common of different sizes.

> If the program and subroutines are compiled with the option -g the
> load-module is OK.
> if the program and subroutines are compiled with the option -O the
> execution
> of the load-module gives errors.

The question is not appropriate for gcc@ mailing list, which is about 
the development of GCC and not its usage. The gcc-help@ or the fortran@ 
lists would be more appropriate.


I have to admit that I have no idea why you get different results for -g 
and -O.

Additionally, it is unclear to me whether you get an error message of 
the compiler or whether your program fails at run time.

Especially, if it is the former: Can you provide more information? For 
instance, a small test case, the exact compiler options you used, the 
error messages you get and the result you expect.

If the latter, try the flag -fno-align-commons. (See description at 
http://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html) For a 
per-version overview about the compiler changes, search for "common" at 
http://gcc.gnu.org/wiki/GFortran#news


Tobias