Issue to track multhreading performance issues with big functions

[Janmajayamall]

range_fn improves with more threads, but the improvement isn't exactly linear. This is directly related to #1 since most of what range_fn does is calculate powers and iterate m loop 255 times. Thus, I think solving #1 will solve this as well. However I would like this to be mentioned here just so that we check back again once #1 is solved.

For the record, I also checked time taken by range_fn (and its most expensive inner parts) on multiple threads. I ran tests on r6i.8xlarge instance.

Thread = 1
Total: 125s
Powers: 73s
Loops: 52s

Threads = 8
Total: 20.8s
Powers: 12.1s
Loops: 8.26s

Threads = 16
Powers: 8.2s
Loops: 5.71s
Total: 14.5s