RFR: JDK-8246751 Mac OS build settings should use -O3

[Sergey Bylokhov]

On 6/8/20 3:06 pm, Claes Redestad wrote:
> Right, -O3 is now likely the default for most files.
> 
> I'm not sure you suggest the reported ~2% difference between -Os and
> -O2/-O3 as an argument against changing to -O3 by default. It might be
> statistically significant - or just noise - but we should at any rate
> be wary of overfitting to a particular (micro-)benchmark.

I guess that should be the opposite way round. Some good numbers other than
noise should be used as an argument of changing -0s to -03 by default.

> 
> It'd also be good to re-run with the new default: when most compilation
> units change to -O3, which optimization level is ideal for an individual
> compilation unit (such as unsafe.cpp) might very well change, since
> what optimizations are available through the build chain can shift
> considerably.

Hope we will get some good improvements, otherwise it is better to use -0s.


-- 
Best regards, Sergey.