Default bit mode
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:
- OBJECT_MODE=32
- Works with 32-bit objects
- OBJECT_MODE=64
- Works with 64-bit objects
- OBJECT_MODE=32_64
- Works with either 32-bit or 64-bit objects
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:
| 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:
- -q64
- -q32
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 it yourself to ensure that the compiler is invoked for the correct bit mode. Alternatively, you can always use the -q32 or -q64 option to specify the bit mode.
