Before installing XL Fortran

Before you install IBM® XL Fortran for AIX®, V15.1, do the following tasks:

Familiarize yourself with the installation image, which contains the installable compiler filesets.
Ensure that system prerequisites such as disk space and operating system are met.
Determine the tasks you need to perform, depending on your installation requirements.
Become either the root user or a user with administrator privileges.

Coexistence with previous version compilers

Installing this version of the compiler does not remove or change previous versions of the compiler, only the Fortran runtime library and the SMP runtime library are migrated to the new versions. This was achieved by differentiating the installation fileset names from those of the previous versions, including the version, release and modification level (V.R.M) in the name, and installing to new locations that include V.R.M in the installation paths.

The compiler invocations from previous compiler installations in the /usr/bin/ directory will not be removed. The new compiler invocations will be installed to the /opt/IBM/xlf/15.1.0/bin/ directory. To invoke this version of the compiler without specifying the full installation path, you must update your PATH or create shortcuts. For details, see Creating shortcuts to the XL Fortran invocation commands.

Upgrading the evaluation copy of the XL Fortran compiler

You can upgrade the evaluation version of the compiler to the licensed version by installing the licensed product package on top of the evaluation package. By following the Basic installation or Advanced installation procedure for the licensed product package, the compiler license can be installed. Shared filesets between the evaluation and licensed versions that have already been installed are reported as Already installed.

Note: If the evaluation version was installed using the advanced (non-default) installation method, and you want to install the licensed version to the same location, you must first remove the evaluation version using rm -rf, or install the licensed version to a different directory than the evaluation version.