Use the -m32 option to compile for the ILP32 32–bit model and —m64 option to compile for the LP64 64–bit model.
The ILP32 model specifies that C-language int, long, and pointer data types are each 32-bits wide. The LP64 model specifies that long and pointer data types are each 64-bits wide and int is 32-bits wide. The Oracle Solaris and Oracle Linux OS also support large files and large arrays under the LP64 data type model.