If this isn't part of the performance boost claimed, then pull it out of this issue.
-Nathan On Fri, Apr 18, 2008 at 12:10 PM, Aleksey Shipilev < [EMAIL PROTECTED]> wrote: > Nathan, > > The method name is inaccurate, right, it can be named like you want. > The reason of performance boost _is_not_ in this method (nevertheless > this method probably is fastest available for rounding). This method > is utility and I see no point in moving it to Math. > > The reason of the performance boost is: > > On Fri, Apr 18, 2008 at 11:51 AM, Aleksey Shipilev < > [EMAIL PROTECTED]<https://mail.google.com/mail?view=cm&tf=0&[EMAIL > PROTECTED]>> > wrote: > >> I'm pushing the idea that > >> this optimization is general because it moves long-latency modulo (%) > >> operations to really cheap mask (&), but to guarantee this, we should > >> guarantee the storage is 2^k, where k is 0..N. > > Thanks, > Aleksey. > > On Fri, Apr 18, 2008 at 9:03 PM, Nathan Beyer <[EMAIL > PROTECTED]<https://mail.google.com/mail?view=cm&tf=0&[EMAIL PROTECTED]>> > wrote: > > So the method 'roundTo2k' is incorrectly named, then? Should it be > > 'roundTo2ToTheK'? Isn't there a Math method that should be used to do > this, > > which in turn should be the focus of optimization? I'd rather see such > a > > "general" optimization pushed into Math and then have all of the > XHashMap > > implementations use the Math methods consistently. > > > > -Nathan > > > > On Fri, Apr 18, 2008 at 11:51 AM, Aleksey Shipilev < > > > > [EMAIL PROTECTED]<https://mail.google.com/mail?view=cm&tf=0&[EMAIL > > PROTECTED]>> > wrote: > > > > > > > Nathan, > > > > > > I think we have a sort of misunderstanding here. I'm not rounding to > > > 2000, rather I round to next power of 2. I'm pushing the idea that > > > this optimization is general because it moves long-latency modulo (%) > > > operations to really cheap mask (&), but to guarantee this, we should > > > guarantee the storage is 2^k, where k is 0..N. > > > > > > Thanks, > > > Aleksey. > > > > > > On Fri, Apr 18, 2008 at 8:44 PM, Nathan Beyer <[EMAIL > > PROTECTED]<https://mail.google.com/mail?view=cm&tf=0&[EMAIL PROTECTED]> > <https://mail.google.com/mail?view=cm&tf=0&[EMAIL PROTECTED]>> > > > > > > > wrote: > > > > I'm sure this optimization shows an improvement in the > serialization > > > use > > > > case, but you'd be hard pressed to say that this improvement will > make > > > 80% > > > > of all uses of HashMap, WeakHashMap and IdentityHashMap better. If > you > > > want > > > > to round to 2000 to improve serialization, then do that in the > > > > serialization. > > > > > > > > I don't think this should be applied as is. > > > > > > > > -Nathan > > > > > > > > > >
