From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [RFC PATCH 03/15] Provide atomic_t functions implemented with
 ISO-C++11 atomics
Date: Thu, 19 May 2016 13:33:29 +0200
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On Thu, May 19, 2016 at 01:31:16PM +0200, Peter Zijlstra wrote:
> Where the __special_marker__ marks the whole { } scope as being the
> inside of LL/SC and all variables must be in registers before we start.
> If the compiler is not able to guarantee this, it must generate a
> compile time error etc..

And note that all LL/SC archs I've checked have very similar constraints
on what can go inside them. And simply taking the most constrained
across the board will work fine.