AMBER Archive (2003)

Subject: g77 on 32 bits cpu (was Re: Nmode recompilation)

From: Tru Huynh (tru_at_pasteur.fr)
Date: Tue Jul 01 2003 - 04:48:15 CDT

On Tue, Jul 01, 2003 at 10:41:33AM +0200, Thomas Steinbrecher wrote:
> Dear AMBER users,
>
...
>
> However if I compile nmode with MAXMEMX=350.000.000 in
> sizes.h, I get the compiler error:
>
> ----------
> _nmode_.f:50:
> real*8 x (MAXMEMX)
> ^
> Array `x' at (^) is too large to handle
> make: *** [nmode.o] Fehler 1
> ----------
>
> Is it possible to compile nmode in a way that lets it use
> some GB of memory?

You will have to use a different compiler.

http://gcc.gnu.org/ml/gcc-help/2002-11/msg00214.html
<quote>
On 32-bit targets, until GCC/g77 version 3.1, the limit was 2**32 bits, which
is 2**26 DOUBLE PRECISION values, or around 65 million.

>From GCC/g77-3.1 onwards, the limit is 2**31 bytes, which means around 262
million DOUBLE PRECISION values. The latter limit is due to the fact that on
32-bit targets, signed integers used in offset calculations cannot be larger
than 2**31-1.

</quote>

Tru 

-- 
Dr Tru Huynh          | http://www.pasteur.fr/recherche/unites/Binfs/
mailto:tru_at_pasteur.fr | tel/fax +33 1 45 68 87 37/19
Institut Pasteur, 25-28 rue du Docteur Roux, 75724 Paris CEDEX 15 France