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Re: string hash performance


Jeff Sturm wrote:

On Wed, 7 Aug 2002, Eric Blake wrote:

In response to Hans answer, String.hashCode does not use
Object.hashCode, so the location of a String object in memory has no
effect on whether hashing would be useful. Thus, if gcj does merge with
classpath, all String objects would become at least 4 bytes larger to
store the cache. Tom, that may be something for you to consider when
you ever do get around to looking at my patch.

I did some benchmarking with the cachedHashCode bits of your patch.
Interestingly, it helped considerably on my interpreter benchmarks,
chopping about 15% off total run time.

Thanks for benchmarking this. It looks like this is a clear win to me. Given that its also what the JDK appears to do, I think we should go ahead and change String to cache the hashCode.

regards

Bryce.



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