RFR: 8247910: Improve alignment and power-of-2 utilities using C++14

[Kim Barrett]

> On Sep 23, 2020, at 5:39 AM, Andrew Haley <aph at redhat.com> wrote:
> 
> On 23/09/2020 09:24, Kim Barrett wrote:
> 
>> gcc5 is the first version of gcc that *claims* to completely support
>> C++14.  That’s the only reason for setting it as the lower limit; it
>> wasn’t based on data.
>> 
>> Rather than potentially contort code to support what is now a pretty
>> old version, I’d prefer we moved forward the minimum required
>> version.
> 
> I'd prefer that too, but it's not just about us developers: there are
> many distros building newer OpenJDK on older systems, and they may not
> have the freedom to change the system-wide C compiler. Given that we
> want to encourage people to use modern OpenJDK releases we should at
> least try to accommodate older compilers.
> 
> I'd say that if we can use GCC 5 with minor changes we should do so,
> but not if it makes a mess of the code.

Sure, but the code that’s failing is nothing out of the ordinary for C++14.  I’m
pretty surprised there’s a failure for anything like that.

I’m also not in a good position to try to track down the problem; if Thomas or
someone else wants to, I’m game for kibitzing, but I’m reluctant to try to drive
the investigation.

> 
> -- 
> Andrew Haley  (he/him)
> Java Platform Lead Engineer
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