The sets of command-line options for the Alpha and x86 editions of the compiler are almost identical. However, the x86 edition supports some options that the Alpha edition does not. Make sure to remove these unsupported options from your makefiles. Some x86 options are supported on Alpha platforms, but with changes. Make sure you use these options correctly in makefiles.
In addition, the Alpha editions support some options that the x86 edition does not. The next three chapters describe these platform-specific options. When porting from x86, however, you only need to worry about the x86 options that are not supported.
Tip For best results on applications with a lot of global data, use the /Gt option, which sets the size threshold for near data, when porting applications to the Alpha platform. Note that you should use /Gt32 with caution and only when necessary as its use can result in complications such as linker errors or disabling of future optimizations. For more information on the use of the /Gt switch, see The /Gt (Set Data Value) Option topic later in this chapter.