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Subject: Re: [boost] [atomic, x86] need another pair of eyes
From: Peter Dimov (lists_at_[hidden])
Date: 2012-12-19 06:27:52

Andrey Semashev wrote:

> On x86 memory view is almost always synchronized (AFAIK, the only
> exception is non-temporal stores, which are usually finalized with
> explicit mfence anyway), so unless the user requests
> memory_order_seq_cst only compiler barrier will suffice. As for
> memory_order_seq_cst, it requires global sequencing, and here's the
> part I'm not sure about. Lock-prefixed ops on x86 are full fences
> themselves, so it looks like no special hardware fence is needed in
> this case either. So unless I'm missing something, mfence could be
> removed as well in this case. Could somebody confirm that?

Where (file/line) is the mfence that can be removed?

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