What's the proper way to use different versions of SSE intrinsics in GCC?

Question

I will ask my question by giving an example. Now I have a function called do_something().

It has three versions: do_something(), do_s

Answer 1

I think that the Mystical's tip is fine, but if you really want to do it in the one file, you can use proper pragmas, for instance:

#pragma GCC target("sse4.1")

GCC 4.4 is needed, AFAIR.