AMBER Archive (2006)

Subject: Re: AMBER: nmode memory problem

From: Atro Tossavainen (atro.tossavainen+amber_at_helsinki.fi)
Date: Fri Aug 25 2006 - 05:10:50 CDT

Ross,

> Support for 64 bit addressing has nothing to do with the language. There is
> no restriction on F77 supporting 64 bit address space. The limitation comes
> from how the compiler chooses to interpret the language.
>
> You should check the man page for your compiler and see if there is an
> option related to 32 bit / 64 bit compilation.

The original poster was on a SGI Onyx 3800 (and has apparently already
figured this out). Figured I'd post the "how to" as William didn't.

In the MIPSpro compiler,

$ man f90
...
     The f90 command accepts the following options:

     -64, -n32 Specifies the Application Binary Interface (ABI).

               Option Action

               -64 Generates 64-bit objects.

               -n32 Generates 32-bit objects. When in effect, the
                         total memory allocation for a program and
                         individual arrays cannot exceed 2 Gbytes.
...

The file /etc/compiler.defaults contains the obvious, and on all of
the SGI machines I've seen, it has always contained "abi=n32".

Therefore, by default, all programs get compiled to the n32 ABI -
perhaps so that it would be possible to run them on O2s and other
ancient beasts (Indigo2 R4400, Indy, etc :) that did not support
the fully 64-bit ABI. 

-- 
Atro Tossavainen (Mr.)               / The Institute of Biotechnology at
Systems Analyst, Techno-Amish &     / the University of Helsinki, Finland,
+358-9-19158939  SGI Nerd          / employs me, but my opinions are my own.
< URL : http : / / www . helsinki . fi / %7E atossava / > NO FILE ATTACHMENTS
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