how to start for x86 cpu with SSE instruction

hi all,
I first touch openVG.
Who can tell me how to start if i try to accelerate some vector functions
by sse instructions on X86 platform?
Questions:

  1. does it make sense for current x86 platform?
  2. where are interfaces for those functions?
  3. how to commit those patches after optimization?

Thanks a lot & Best Regards
Ling