The AIX operating system provides support for the OBJECT_MODE environment variable to enable the user to obtain a 64-bit development environment. AIX tools use the setting of OBJECT_MODE to determine the type of object to be used or created. The OBJECT_MODE environment variable has three recognized settings:
The XL Fortran compiler determines the default bit mode through the setting
of the OBJECT_MODE environment variable at the time of
invocation. The following table shows the default bit mode and options
that are set for each setting of the OBJECT_MODE environment
variable:
Table 17. Default bit mode determined by the setting of OBJECT_MODE
| OBJECT_MODE Setting | Default Bit Mode | Default Option Set |
|---|---|---|
| unset | 32-bit | -q32 |
| 32 | 32-bit | -q32 |
| 64 | 64-bit | -q64 |
| 32_64 | Not permitted | n/a |
Specification of the following options on the command line or in the configuration file overrides the default option set:
| Important Note |
|---|
|
Using OBJECT_MODE to determine the default bit mode can have serious implications if you are not aware of the setting of OBJECT_MODE at the time of invocation. For example, you may not be aware that OBJECT_MODE has been set to 64, and you may unexpectedly obtain 64-bit object files. We strongly urge you to be aware of the setting of OBJECT_MODE at all times and to set OBJECT_MODE yourself to ensure that the compiler is invoked for the correct bit mode. |
64-bit support is provided in the Fortran module files that are shipped with XL Fortran. The 64-bit Fortran modules have the same names as the 32-bit Fortran modules and are shipped in a separate directory, /usr/lpp/xlf/include_64. The module files that support the 64-bit LDT are shipped in the /usr/lpp/xlf/include_64ldt directory.