RFR (XS) CR 8058643: (str) Re-examine hashCode implementation

[Aleksey Shipilev]

On 09/25/2014 11:40 AM, Aleksey Shipilev wrote:
>> This is for HotSpot compiler guys to answer. Theoretically I think it is
>> possible. But it would have to be tailored to the very specific use case
>> and I don't know if such specific transformation would have wide-enough
>> applicability. If it would only speed-up String.hashCode and very
>> similar loops, it is less trouble to do that by hand in one or few
>> places...
> 
> I would think this happens in user-specified hashCode() over arrays.
> IDEs would routinely inject the loop like that or delegate to
> Arrays.hashCode, that does the same loop.
> 
> In other words, I would like to see this fixed on compiler side. This
> seems to be the strength-reduction playing tricks with loop unrolling,
> I'll submit a bug shortly.

https://bugs.openjdk.java.net/browse/JDK-8059113

-Aleksey.