Review Request CR#7118743 : Alternative Hashing for String with Hash-based Maps

Rémi Forax forax at
Mon May 28 08:36:09 UTC 2012

On 05/28/2012 09:13 AM, Andrew Haley wrote:
> On 05/26/2012 12:29 PM, Doug Lea wrote:
>> (Sometime this summer, I hope to write up something on
>> the various "little" coding issues that may be applicable
>> for improving performance of library code. As people
>> mentioned wrt the similar private accessor case,
>> most of these issues are not interesting/useful for
>> application code, but there's no reason not to address
>> them inside heavily used core libraries. The effects
>> are difficult to measure in any small set of tests using
>> these library components, so usually the best course of action
>> is to avoid known potential performance issues.)
> The thing that bothers me about this is that such optimizations may be
> rather VM-specific, sometimes to the extent of depending on how
> HotSpot generates code for a particular case.  Given that the OpenJDK
> libraries are now used more widely, and hopefully this will increase,
> what shall we do?
> Andrew.

Usually it's more to avoid common pitfalls than trying to trigger a 
specific VM optimization.


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