Re: Anyone knowlegable about valgrind ? Was: Re: g77 and valgrinderror?

[Toon Moene <toon at moene dot indiv dot nluug dot nl>]

bvds@bvds.geneva.edu wrote:

> > I do not know anything about valgrind, but the Fortran code is perfectly 
> > OK.  It uses an automatic array x in subroutine fsub that is dimensioned 
> > using the dummy argument i, which is an extension of Fortran 77, but 
> > allowed in Fortran 90 and supported by g77.
>
> Yes, the code itself is OK...
> Another detail that I forgot to mention is that the valgrind
> error goes away when i=350.  Is there anything about memory
> allocation in g77 that would change with increasing i?
>
> I have also put this question to the valgrind people, but
> *they* probably don't know much about g77.

I wouldn't know why 360 is a "magic number", but g77 doesn't do anything 
but place the automatic array on the stack.  Therefore, we have to deal 
with 16 * 360 * 360 bytes = slightly over 2 megabytes of stack space.

I can't see why this would be a problem (unless other automatic arrays 
are also dimensioned using `i'.

Cheers,

--
Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
Maintainer, GNU Fortran 77: http://gcc.gnu.org/onlinedocs/g77_news.html
A maintainer of GNU Fortran 95: http://gcc.gnu.org/fortran/