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Re: Potentially merging cxx-mem-model with mainline.
- From: Richard Guenther <richard dot guenther at gmail dot com>
- To: Benjamin Kosnik <bkoz at redhat dot com>
- Cc: Andrew MacLeod <amacleod at redhat dot com>, GCC <gcc at gcc dot gnu dot org>
- Date: Thu, 27 Oct 2011 10:55:59 +0200
- Subject: Re: Potentially merging cxx-mem-model with mainline.
- References: <4EA8296F.email@example.com> <20111026093100.42f49182@shotwell>
On Wed, Oct 26, 2011 at 6:31 PM, Benjamin Kosnik <firstname.lastname@example.org> wrote:
>> Whats left
>> Functionality is pretty much complete, but there are a few minor lose
>> ends still to deal with. They could be done after a merge, in the
>> next stage, or required before... you tell me :-)
>> - potentially implement -f[no]-inline-atomics ?(to never produce
>> inline code and always call the library) and
>> -f[no]-atomic-compare-swap-loop (To not fall back to a
>> compare_and_swap loop to implement missing functionality)
>> - unaligned objects have undefined behaviour at the moment.
>> Behaviour could be defined and add alignment checks and a parameter
>> to __atomic_is_lock_free() for alignment checking purposes. ?Anything
>> which doesn't map to one of the properly aligned ?5 sized built-ins
>> gets a library call.
>> - A bit of C++ template restructuring in the include files to remove
>> the old fall back locked implementation and fully use the new
>> __atomic builtins. (*in progress now*)
> Hit me off-line about this. Hopefully I can help expedite.
>> - Change external library calls for __atomic_op_fetch routines.
>> (*patch submitted already*)
>> - There are a bunch of new tests that have been developed along the
>> way, but I I expect to spend the next 2 months writing more detailed
>> and specific runtime and compile time tests. And of course, fixing
>> any of the fall out from those tests.
> Yes. I don't see this as a blocker for the merge.
>> The final word
>> So what is the opinion/consensus on merging the branch? ?It would be
>> nice to get this infrastructure in place for this release so we can
>> get people to start using it, and then we can work out any issues
>> that arise.
>> I'd have Aldy do the actual merge because if I do something will go
>> amok for sure. ?I wont be around this weekend to fix any fallout, but
>> I am around until Friday evening. ?I'm around all next week. ?I don't
>> anticipate much problem since this is all new functionality for the
>> most part, and mainline was merged with the branch a week or two ago.
> I am really expecting this branch to be merged for 4.7. The current
> status is very presentable IMHO.
If you get (or already got) ack from maintainers covering the areas you
touch then I am fine with merging this branch for 4.7 from a RM point
of view. You do not have too much time left though, see my upcoming