Tamron and Sigma lens on Nikon D5100?

Does Tamron SP AF 17-50mm F/2.8 XR Di II VC and non-VC autofocuses on Nikon D5100?
And does Sigma 17-50mm F2.8 EX DC OS HSM autofocuses on it too? Thanks! :)
>>> Tamron and Sigma lens on Nikon D5100?