Re: [Boost-bugs] [Boost C++ Libraries] #9426: boost::atomic gcc-cas related specializations patch

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #9426: boost::atomic gcc-cas related specializations patch
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-11-23 15:14:40

#9426: boost::atomic gcc-cas related specializations patch
-------------------------------------+--------------------------
  Reporter:  Piotr Kobzda <pikob@…>  |      Owner:  timblechmann
      Type:  Patches                 |     Status:  new
 Milestone:  To Be Determined        |  Component:  atomic
   Version:  Boost 1.55.0            |   Severity:  Problem
Resolution:                          |   Keywords:
-------------------------------------+--------------------------

Comment (by timblechmann):

 iirc the `__GCC_HAVE_SYNC` macros have been introduced with a later gcc
 version, so it is probably a good idea only to use the gcc-cas version
 when these macros are available.

 regaring arm, it may actually be a good idea to use gcc-cas on armv7,
 because it provides a double-width ll/sc, which is currently not supported
 by boost.atomic (but quite useful for many lock-free algorithms). or
 implement the complete arm support in assembly to avoid the ll/sc
 emulating cas emulating atomics issue ...

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/9426#comment:4>
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