[Boost-bugs] [Boost C++ Libraries] #2525: More architectures that do not support __sync_fetch_and_add_4

Subject: [Boost-bugs] [Boost C++ Libraries] #2525: More architectures that do not support __sync_fetch_and_add_4
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-11-22 11:30:06

#2525: More architectures that do not support __sync_fetch_and_add_4
---------------------------------------------+------------------------------
 Reporter:  Steven Robbins <smr_at_[hidden]>  |       Owner:  pdimov   
     Type:  Bugs                             |      Status:  new      
Milestone:  Boost 1.38.0                     |   Component:  smart_ptr
  Version:  Boost 1.37.0                     |    Severity:  Problem  
 Keywords:                                   |  
---------------------------------------------+------------------------------
 Hi,

 As noted in #2263, Boost makes the incorrect assumption that if the
 following condition is true:

 defined( GNUC ) && ( GNUC * 100 + GNUC_MINOR >= 401 )

 then GCC sync primitives (e.g. sync_lock_test_and_set, sync_fetch_and_add)
 are available.

 Currently, hppa and arm are listed as exceptions.  However, building Boost
 on Debian's 14 architectures suggests that some more exceptions are
 needed: __armel__ (ARM in little endian mode), __m68k__ and __sparc__.
 I'm attaching a patch to atomic_count.hpp to this effect.

 When using GNU C++ however, that patch means that all those machines fall
 through to atomic_count_gcc.hpp, which is known to be broken for GCC > 4.1
 (c.f. #1084, never applied).  I'm attaching a patch for this problem, too.

 Note that these patches are only for the problems I noticed while building
 Boost, and only because we also build "tools/bcp", which happens to use
 shared_ptr.  From grepping the sources it appears that there are a few
 others.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/2525>
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