RFR: 8183574: Unify the is_power_of_2 functions

[Claes Redestad]

On 2020-02-13 15:47, Stefan Karlsson wrote:
> Hi all,
> 
> Please review this patch to consolidate all is_power_of_2 functions into 
> one template function and place it in the existing powerOfTwo.hpp file.
> 
> To resolve a circular dependency between globalDefinitions.hpp and 
> powerOfTwo.hpp, I also moved exact_log2 and exact_log2_long. These 
> functions take a power-of-two value and returns the log2 value, so I 
> think it makes sense to move them to powerOfTwo.hpp.
> 
> https://cr.openjdk.java.net/~stefank/8183574/webrev.01

Looks good!

It seems exact_log2 and exact_log2_long could also be replaced by a
single template function, but that might be better suited as a follow-
up.

Thanks!

/Claes