RFR (XS) 8238909: x86_32 fails gtest:power_of_2

[Claes Redestad]

On 2020-02-12 21:30, Aleksey Shipilev wrote:
> On 2/12/20 7:45 PM, Aleksey Shipilev wrote:
>> Bug:
>>    https://bugs.openjdk.java.net/browse/JDK-8238909
>>
>> Fix:
>>    https://cr.openjdk.java.net/~shade/8238909/webrev.01/
> 
> Scratch that, Stefan suggested a cleaner version:
>    https://cr.openjdk.java.net/~shade/8238909/webrev.02/

Looks good, and nice catch. The use of is_power_of_2 was carried
forward from a z-only helper method that is 64-bit only, so we all
missed that it might be problematic on 32-bit.

As a follow-up RFE (that I can volunteer to take care of) I'd suggest
moving is_power_of_2_t from align.hpp to powerOfTwo.hpp and invert the
dependency.

The methods in globalDefinitions are hard to disentangle. And my gut
feeling is that we should move away from any operations that uses
intptr_t as a type for arithmetic operations in favor of template
functions.

/Claes