Jimmy,Jing Lv wrote:
> I'm not strongly against this commit, but just as I explained in
> the first mail, to make the numBuckets a power of two (&(bucketsize -
> 1)) is always good, but the simple right shift (>>2) may cause some
> benchmark improved (properly in these benchmarks hashcode is directly
> identityHashCode) while others are reduced (hashcode are
> user-defined). A known reduced benchmark is specjbb.
> I don't know when will vm improve their hashcode implementation,
> and different vms will re-act to this at different time, so I doubt
> the best way for applying simply shift ( >>2 ) is waiting for vm to
> improve themselves and do no change to classlib. However this is not a
> very urgent issue :)
Ok, how about we flip it around then. I'll modify the code to compute
int bucket = hashCode & (numBuckets - 1);
with the understanding that our current VMs are penalized until they
enhance their identityHashCode implementations?
Anyone object to doing it this way around?
Regards,
Tim
