This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug fortran/40773] gfortran 4.4.0 -O3 exhausts memory in 127.wrf2
- From: "kargl at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 16 Jul 2009 20:29:19 -0000
- Subject: [Bug fortran/40773] gfortran 4.4.0 -O3 exhausts memory in 127.wrf2
- References: <bug-40773-17946@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #6 from kargl at gcc dot gnu dot org 2009-07-16 20:29 -------
(In reply to comment #5)
> (In reply to comment #4)
> > Compiles OK at -O2, but more slowly than with 4.1.2:
> >
> > 4.1.2 4.4.0
> > -O2:
> > real 1m19.827s real 2m58.945s
> > -O3:
> > real 1m30.645s real 10m5.166s
> >
> > Even if -O3 ultimately generates correct code in some suitably large
> > configuration,
> > it may be that some optimizer
> > algorithms could stand tuning to avoid time-consuming
> > but ultimately unprofitable blind alleys.
> >
>
> Hmmm, something is definitely admiss here. After 22 minutes of
> compiling with -O3 on my system, f951 'appears' stuck with only
> 450 MB of used memory. I attached ktrace to the process and
> found
After 26 minutes, I suddenly see in top(1)
50879 sgk 1 -20 0 7346M 6724M swread 1 26:21 1.51% f951
so -O3 is causing a massive increase in the amount of memory required.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40773