__int64 on a 32-Bit machine?

Question

I just tried something in MSVC 2010 on my 32-bit machine here and found out that I can use __int64 in my programs - which actually work!

• How is that possible?<

Answer 1

Why do you find it surprising? There's nothing to prevent the compiler from supporting 64-, 128- or more-bit integer types on a 32-bit machine. The compiler can even support 57- and 91-bit types, if it feels like it. In practice supporting 2N-bit integer arithmetic on an N-bit machine is a relatively easy task, since the instruction set of a typical machine is often designed with this kind of functionality in mind.