Installing the Intel Fortran compiler

The Intel Fortran compiler (now called Intel Visual Fortran Composer XE 2011 for Windows) works well with GEMPACK -- but you need to match the Fortran version with your GEMPACK Release:

Intel Fortran version 10.1 works with GEMPACK Release 10.0-000 (April 2008) or later.
Intel Fortran version 11.0 and 11.1 work with GEMPACK Release 10.0-001 (April 2009) or later.
Intel Fortran version 12.0 works with GEMPACK Release 11.0 or later.

The current Release of GEMPACK (11.0) works well with any of Intel Fortran versions 10.1 to 12.

Download from Intel the version appropriate to your GEMPACK release. Intel allows customers with a current support services licence (usually 1 year from date of purchase) to download previous Fortran versions. The procedure is described here.

Early November 2010, Intel released version 12.0 of their compiler, now with the new name Intel® Visual Fortran Composer XE 2011 for Windows (formerly known as Intel® Visual Fortran Compiler Professional Edition for Windows). This version requires GEMPACK Release 11.0 (Nov 2011) or later. Any of the older Intel Fortran versions 10.1, 11.0 or 11.1 work fine with GEMPACK 11 -- there is no need to upgrade your Fortran.

Installation instructions for installing Intel Visual Fortran version 10.1, 11.0, and 11.1 are below.

Use Intel Fortran 10.1.021 or later

We recommend Intel Fortran 10.1.021 (Build 20080312) or later [type "ifort" at command line to see your version/build numbers]. If you are already using 10.1.021 or later, there is no reason to upgrade to Version 11.1. If you have an earlier version of Intel Fortran 10.1, we advise you to update (you may be able to do this for free at the Intel website).Usually when you purchase Intel Fortran, you are allowed for a year to download free upgrades. We recommend that you take advantage of this before your year is up.

Installing Intel® Visual Fortran Compiler 12.0 for Release 11.0 (October 2011) or later Source-code GEMPACK
Installing Intel® Visual Fortran Compiler 11.1 for Release 10.0-001 (April 2009) or later Source-code GEMPACK
Installing Intel® Visual Fortran Compiler 11.0 for Release 10.0-001 (April 2009) or later Source-code GEMPACK
Installing Intel® Visual Fortran Compiler 10.1 for Release 10.0-000 (April 2008) or later Source-code GEMPACK
Advice for uninstalling Intel Visual Fortran
Problem finding Intel Fortran licence file

Windows 7

Issues have been reported with Intel Fortran and Windows 7, mentioned here. If using Windows 7, you may need to upgrade to Intel Fortran 11.1.048 or later.

Optimization bug in Intel Fortran 10.0 and early 10.1

32-bit Intel Fortran 10.0 (and early 10.1) has a bug in the optimizer, which conflicts with the faster-running compile options which are set by default when you install Release 10.0-001 (April 2009) or later Source-code GEMPACK. The bug was fixed for Intel Fortran 10.1.021 and later. If BOTH of the following conditions hold:

You are using Intel Fortran 10.0 (which is unlikely) or 10.1 prior to 10.1.021 (Build 20080312)
You installed Release 10.0-001 (April 2009) or later Source-code GEMPACK

you may need to:

either (and preferably), upgrade to Intel Fortran 10.1.021 or later; then reinstall GEMPACK
or, work around the problem as described below.

To check your version of Intel Fortran, type IFORT at the command prompt.

Working around the problem

Open a command prompt in your GEMPACK folder.
Run O1FIG.BAT.
Run BuildGP.EXE

The effect of the above is to re-compile your GEMPACK programs and libraries with less aggressive optimization settings that avoid the optimization bug. The downside is that your programs run a bit slower.