RFR: 8246032: Implementation of JEP 347: Adopt C++14 Language Features in HotSpot

[Kim Barrett]

> On Jun 5, 2020, at 7:57 PM, Magnus Ihse Bursie <magnus.ihse.bursie at oracle.com> wrote:
> 
> On 2020-06-05 13:59, Jim Laskey wrote:
>> I know there was a discussion about this elsewhere but I would like to take the opportunity to correct this now
>> 
>> make//autoconf/flags-cflags.m4:241
>> 
>> […]
>> MacOSX has been paying a historic and significant performance penalty for no valid reason.
> This might be a valid change, but it has nothing to do with C++14, and changing it at the same time will increase risk for unrelated strange errors. Please open a separate JBS issue for this requested change.

I was going to say much the same thing.  I don’t want to add that to the C++14 mix.  I don’t even
know for sure that it’s a desirable change.  I’ve worked on projects that got better (measured)
performance from -Os than from other global alternatives. One would need to do a bunch of
performance testing and might need to go more deeply into the options to really optimize things.