Is there any way to increase the speed of preprocessing?

Dr. Liu, Thanks for you great work!

When I try to apply it to an application, I found it's quite slow and not suitable for calculating the similarity of massive sentence pairs(it takes around 6 hrs to process 30k sentence pairs with `use_cd=False` on i7-8700K CPU). 

I'll appreciate it if you can provide a way to accelerate this progress.