If using the Intel v10.1.x compilers to build a 64-bit version, by default (default installation), Intel invokes the 64-bit compiler. But yes, you can use the "-m64" flag as well.

Warner Yuen

Scientific Computing 

Consulting Engineer

Apple Computer

email: wyuen@apple.com

Tel: 408.718.2859

On Oct 9, 2008, at 10:15 PM, users-request@open-mpi.org wrote:

Message: 2
Date: Thu, 9 Oct 2008 17:28:38 -0400
From: Jeff Squyres <jsquyres@cisco.com>
Subject: Re: [OMPI users] build failed using intel compilers on mac os
To: Open MPI Users <users@open-mpi.org>
Message-ID: <897C21DB-CB73-430C-B306-8E492B247B34@cisco.com>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes

The CXX compiler should be icpc, not icc.

On Oct 7, 2008, at 11:08 AM, Massimo Cafaro wrote:

<openmpi build>

Dear all,

I tried to build the latest v1.2.7 open-mpi version on Mac OS X  
10.5.5 using the intel c, c++ and fortran compilers v10.1.017 (the  
latest ones released by intel). Before starting the build I have  
properly configured the CC, CXX, F77 and FC environment variables  
(to icc and ifort). The build failed due to undefined symbols.

I am attaching a log of the failed build process.
Any clue? Am I doing something wrong?

Also, to build a 64 bit version it is enough to supply in the  
corresponding environment variables the -m64 option ?
Thank you in advance and best regards,