MaxBCEAEstimateSize and inlining clarification
john.r.rose at oracle.com
Thu Sep 8 22:13:12 UTC 2016
On Sep 8, 2016, at 2:48 PM, Krystal Mok <rednaxelafx at gmail.com> wrote:
> On Thu, Sep 8, 2016 at 9:32 AM, Vitaly Davidovich <vitalyd at gmail.com <mailto:vitalyd at gmail.com>> wrote:
> By the way, and this is off-topic to this thread (apologies), but while we're discussing marking classes/methods final, are there any other footprint advantages to doing it even if CHA will devirt calls properly? So removing the need to register dependencies is one, and is good. Are the vtables smaller for these cases? Anything else that's an added benefit (from JVM runtime standpoint)?
> Well...nothing that really stands out.
> Removing the need for registering the dependencies is certainly a good thing, but it doesn't really matter that much.
> The vtable won't be necessarily be smaller, it depends. What's guaranteed is that a final method won't need a *new* vtable entry.
> Because "final" can be labeled on a method that's virtual in some base class, and is only "final" on some derived class. That vtable slot in the derived class is going to be inherited from the base class and then set to the overriding target, so no saving at all in this case.
HotSpot is overly generous with v-table entries. IIRC even privates get their own entries, for convoluted reasons.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the hotspot-compiler-dev