[MITgcm-support] domain size limit?

[Martin Losch]

Hi Sergey,

I don’t know if Ryan’s compiler is the same (probably similar), but here’s mine:

csysm15::build> gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-darwin13.0.0/4.9.0/lto-wrapper
Target: x86_64-apple-darwin13.0.0
Configured with: ../gcc-4.9-20130929/configure --enable-languages=c,c++,fortran
Thread model: posix
gcc version 4.9.0 20130929 (experimental) (GCC) 

Martin

On Dec 3, 2013, at 9:48 AM, fancer lancer <fancer.lancer at gmail.com> wrote:

> Hi Ryan,
> 
> Could you please, show the result of the command "gfortran -v". I suppose, that you used the 32-bit version of the compiler that is why you overcame the limit.
> 
> Sincerely,
> -Sergey
> 
> 
> On Tue, Dec 3, 2013 at 12:29 PM, Martin Losch <Martin.Losch at awi.de> wrote:
> Hi Ryan,
> 
> I can only reproduce the problem with tutorial_barotropic_gyre (and gcc/gfortran 4.9 on OSX 10.9).
> 
> By how much do you have to repduce the domain size to make it work?
> 
> The simplest solution that I found: instead of sNy=1600 and nSy = 1 use sNy=800 and nSy = 2. It’s a little bit of cheating, isn’t it?
> 
> Martin
> 
> On Dec 3, 2013, at 6:00 AM, Ryan Abernathey <ryan.abernathey at gmail.com> wrote:
> 
> > Dear Super Modelers,
> >
> > I found a weird error when trying to compile a large domain (500 x 1600 x 1) on a single processor. On the final link stage of the build, I get:
> > ld: 32-bit RIP relative reference out of range (2162237024 max is +/-4GB): from _find_beta__ (0x100227200) to _rhoden.4514 (0x18103AE80) in '_find_beta__' from find_alpha.o for architecture x86_64
> > The error disappears if I just reduce sNx * sNy. I guess this has something to do with running out of memory address space? Is it weird that "32-bit RIP" is being used even though my platform is 64 bit?
> >
> > My one weak attempt to overcome this was by adding -fPIC to my FFLAGS. No success.
> >
> > Is there any way to overcome this problem, or am I hitting some kind of fundamental limit to the domain size?
> >
> > Thanks for your suggestions,
> > Ryan
> >
> >
> > My platform is Mac OX 10.8.5, Intel Core i7, gcc version 4.2.1 (via xcode), gfortran GNU Fortran (GCC) 4.7.1. My optfile is the default darwin_amd64_gfortran.
> >
> > From my SIZE.h:
> >      &           sNx = 500,
> >      &           sNy = 1600,
> >      &           OLx =   4,
> >      &           OLy =   4,
> >      &           nSx =   1,
> >      &           nSy =   1,
> >      &           nPx =   1,
> >      &           nPy =   1,
> >      &           Nx  = sNx*nSx*nPx,
> >      &           Ny  = sNy*nSy*nPy,
> >      &           Nr  =   1)
> >
> >
> >
> >
> > _______________________________________________
> > MITgcm-support mailing list
> > MITgcm-support at mitgcm.org
> > http://mitgcm.org/mailman/listinfo/mitgcm-support
> 
> 
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