Product version migration

If you have a previous version of the compiler, you can replace it with the current version. You can also maintain multiple versions of the compiler on your system.

Before installing IBM® XL C/C++ for AIX®, V11.1, any previously installed versions of the compiler should be uninstalled. If you intend to maintain multiple versions of XL C/C++ on your system, refer to Advanced installation, otherwise see Uninstalling XL C/C++.

If you are upgrading to XL C/C++ V11.1 using a basic installation, any previous versions of the filesets already installed on your system are automatically detected and migrated to the current version.

Once IBM XL C/C++ for AIX, V11.1 is installed, older compiler versions cannot be installed unless V11.1 is uninstalled first.