Why use log() to combine instead of log2()

[its-sandy]

https://github.com/IntelLabs/SLIDE_opt_ia/blob/29e40b45d89d62d50bc4a86df5b804b0594ce514/SLIDE/LSH.cpp#L115

Could you please explain the reason for changing log2() to log() ? Given that each of the K hash functions has log2(binsize) bits, is it not correct to shift the hash functions by those number of bits in order to combine them? Wouldn't log2() give a larger value for the shift length, hence increasing the range of the hash function?