Once you write an application for the x86 version of Windows NT, it is easy it is to get it to run on RISC versions of Windows NT. This is because there are virtually no processor dependencies in the Win32 API.
However, an application’s performance can suffer on a RISC machine if its data is not properly aligned. To handle this problem, align the data in your source for both RISC and non-RISC machines. You want to assure that you have DWORDs on DWORD boundaries, and LARGE_INTEGERS on 8-byte boundaries.
Normally the compiler makes sure that data is correctly aligned. However, data structures from a file or from over a network may not follow alignment rules. With the Microsoft Visual C++ compiler, you will want to use the PACK and UNPACK pragmas to define these structures, and the modifier UNALIGNED to declare pointers to them. If you do not do this, you get alignment faults. On some systems, these simply generate traps, and you can fix your program. However, some systems handle your unaligned references with a trap handler. This slows down your application and can be difficult to track down.