RFA (libstdc++): PATCH to implement C++17 over-aligned new

[Jonathan Wakely]

On 16/09/16 13:12 +0100, Jonathan Wakely wrote:
>On 16/09/16 11:56 +0100, Jonathan Wakely wrote:
>>On 16/09/16 11:37 +0200, Marc Glisse wrote:
>>>Is the division (by a non-constant denominator) really necessary?
>>
>>Probably not, but I've asked the committee for clarification what this
>>function should do when called with an invalid alignment.
>>
>>>Since align has to be a power of 2, x % align should be the same 
>>>as x & (align - 1), for instance.
>>
>>Thanks, if it's UB to call it with alignments that aren't a power of
>>two then we can do that.
>
>I've committed the patch now, to fix the failures for Solaris. I'll
>revisit it when I get clarification from the committee about invalid
>alignment arguments.

I missed 18.6.2/1 which is clear that we don't have to support invalid
alignments passed to operator new, so I'm committing this.

Tested x86_64-linux.



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