With all of the talk that we hear about Linux and using a 64bit platform, you must be asking yourself if its even worth it? The short answer is yes, after awhile that is.


"With the pervasiveness of 64-bit architectures, it's more important than ever that your Linux® software be 64-bit ready. Learn how to avoid portability pitfalls when making declarations and assignments, bit shifting, typing, formatting strings, and more."
 
Linux was one of the first cross-platform operating systems to use 64-bit processors, and now 64-bit systems are becoming commonplace in servers and desktops. Many developers are now facing the need to port applications from 32-bit to 64-bit environments. With the introduction of Intel® Itanium® and other 64-bit processors, making software 64-bit-ready has become increasingly important.
 
As with UNIX® and other UNIX-like operating systems, Linux uses the LP64 standard, where pointers and long integers are 64 bits but regular integers remain 32-bit entities. Although some high-level languages are not affected by the size differences, others such as the C language may be.
 
The effort to port an application from 32 bits to 64 bits might range from trivial to very difficult, depending on how these applications were written and maintained. Many subtle issues can cause problems even in a well-written, highly portable application, so this article outlines these issues and suggests ways to deal with them...


Source: IBM