New Register allocation algorithm

Hi,
I wanted to write a new register allocation algorithm. I wrote it the same way RegAllocFast has been written and registered it. I added it to ForceCodegenLinking struct as well. But after build, it is not listed in llc --help. I tried to change the registered name of greedy algorithm to something else and that doesnt seem to be reflecting in llc help either.

Am i supposed to build llvm completely again? Or am i missing something?

Thanks