2.4.4 Compiling for 64–Bit Memory Model

Use the new -m64 option to specify the memory model of the target compilation. The resulting executable will work only on 64-bit UltraSPARC or x86 processors under Solaris OS or Linux OS running a 64-bit kernel. Compilation linking, and execution of 64-bit objects can only take place in a Solaris or Linux OS that supports 64-bit execution.