ClassValue perf?

[MacGregor, Duncan (GE Energy Management)]

On 25/04/2015 13:44, "Remi Forax" <forax at univ-mlv.fr> wrote:
>On 04/24/2015 11:17 PM, John Rose wrote:
>> On Apr 24, 2015, at 5:38 AM, Charles Oliver Nutter
>><headius at headius.com> wrote:
>>> Hey folks!
>>>
>>> I'm wondering how the performance of ClassValue looks on recent
>>> OpenJDK 7 and 8 builds. JRuby 9000 will be Java 7+ only, so this is
>>> one place I'd like to simplify our code a bit.
>>>
>>> I could measure myself, but I'm guessing some of you have already done
>>> a lot of exploration or have benchmarks handy. So, what say you?
>> I'm listening too.  We don't have any special optimizations for CVs,
>> and I'm hoping the generic code is a good-enough start.
>> ‹ John
>
>I don't think I have a code that use ClassValue in a fast path .
>I have several codes that uses a ClassValue when a callsite becomes
>megamorphic but in that case, I have found that the perf of
>ClassValue.get() hard to separate from the fact that I also loose
>inlining.

I did have CV code in my fast paths for dispatch that I could do useful
class hierarchy analysis on, but couldn¹t get it to run quite fast enough
to be worthwhile. Whether that was due to the CV part or other factors I
didn¹t fully analyse as CHA was not applicable to as many callsites as I¹d
hoped.

Duncan.