32 bit & 64 bit optimization?

[lindsey laho]

Question: How can I make programs that run better for different operating systems? (64bit and 32 bit)

I know that 64 bit programs are supposed to be faster on a 64 bit operating system than on a 32 bit...
I'm using WXDev C++ which is basically the same as Dev C++.

Possible Rumor: I've heard from some people that to make a program run faster you must compile it on the machine that you wish to use it on.

Qeustion based on Rumor: So would I have to have a 64 bit Operating system to create a 64 bit program? Or is the Rumor false?

[kbw]

There's more to hardware these days than word size.

You can't really be sure until you run and time it. Looking at the generated assembler might help you get a feel for it.

[LB]

False rumor. The compiler may run faster if it is a 64-bit compiler, but the generated code should be the same - as long as you tell your compiler the same things on each computer you use it on.