Currently it just converts a private key WIF to a public key hex and then exits. And it looks like there is an flag to do uncompressed key conversion called isComp which is passed to the internal function that does the conversion but it's not enabled by default. https://github.com/JeanLucPons/VanitySearch/blob/1bc508a19e2066777f3fb1a020f68f8705daf0f4/main.cpp#L469
add read from input file for -cp option where it can read bunch of private key in hex format from text file instead of single computation to leverage gpu horse power for converting pre computed private keys and converting to compressed and uncompressed address format there is no tool out there does this using gpu i am pretty most people want their pre computed private keys to be converted as a side benefit.
Why with GPUs? That option is basically a conversion utility that already runs quickly, it doesn't start a vanity address search like the others.
i see however i have large amount of pre computed private keys which is costing me dearly to convert it to addresses as the cpu is not powerful enough to convert millions of private key to address the tool already does that it will be not hard for it to read bunch of private keys in hex format and do what it does with gpu if you search for converting pre computed private keys you see hundreds of result but all made for cpu but most people want it to be fast this is the only tool that takes single private key hex format and convert it to address however the power of gpu is wasted since many people have millions of private keys