I saw a "making of" thing (sadly I no longer have the YouTube link) where Theron and the director discussed how the fight scenes were modified. Things you see as single take are in fact that way, but they do cut fairly often. You don't get Jackie Chan-style extended sequences, but rather 4-6 moves in a sequence as opposed to the one or two that were originally planned. She also improvised/suggested some of the bits where you see her use things in the environment.

And yeah, that whole thing is pretty intense.