text: #ifndef AUTOBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CW_X86_HPP_INCLUDED
  #define AUTOBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CW_X86_HPP_INCLUDED
  
  // MS compatible compilers support #pragma once
  
  #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  # pragma once
  #endif
  
  //
  //  detail/sp_counted_base_cw_x86.hpp - CodeWarrion on 486+
  //
  //  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
  //  Copyright 2004-2005 Peter Dimov
  //  Copyright 2005 Rene Rivera
  //
  //  Distributed under the Boost Software License, Version 1.0. (See
  //  accompanying file LICENSE_1_0.txt or copy at
  //  http://www.boost.org/LICENSE_1_0.txt)
  //
  //
  //  Lock-free algorithm by Alexander Terekhov
  //
  //  Thanks to Ben Hitchings for the #weak + (#shared != 0)
  //  formulation
  //
  
  #include <autoboost/detail/sp_typeinfo.hpp>
  
  namespace autoboost
  {
  
  namespace detail
  {
  
  inline int atomic_exchange_and_add( int * pw, int dv )
  {
      // int r = *pw;
      // *pw += dv;
      // return r;
  
      asm
      {
          mov esi, [pw]
          mov eax, dv
          lock xadd dword ptr [esi], eax
      }
  }
  
  inline void atomic_increment( int * pw )
  {
      //atomic_exchange_and_add( pw, 1 );
  
      asm
      {
          mov esi, [pw]
          lock inc dword ptr [esi]
      }
  }
  
  inline int atomic_conditional_increment( int * pw )
  {
      // int rv = *pw;
      // if( rv != 0 ) ++*pw;
      // return rv;
  
      asm
      {
          mov esi, [pw]
          mov eax, dword ptr [esi]
      L0:
          test eax, eax
          je L1
          mov ebx, eax
          inc ebx
          lock cmpxchg dword ptr [esi], ebx
          jne L0
      L1:
      }
  }
  
  class sp_counted_base
  {
  private:
  
      sp_counted_base( sp_counted_base const & );
      sp_counted_base & operator= ( sp_counted_base const & );
  
      int use_count_;        // #shared
      int weak_count_;       // #weak + (#shared != 0)
  
  public:
  
      sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
      {
      }
  
      virtual ~sp_counted_base() // nothrow
      {
      }
  
      // dispose() is called when use_count_ drops to zero, to release
      // the resources managed by *this.
  
      virtual void dispose() = 0; // nothrow
  
      // destroy() is called when weak_count_ drops to zero.
  
      virtual void destroy() // nothrow
      {
          delete this;
      }
  
      virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
      virtual void * get_untyped_deleter() = 0;
  
      void add_ref_copy()
      {
          atomic_increment( &use_count_ );
      }
  
      bool add_ref_lock() // true on success
      {
          return atomic_conditional_increment( &use_count_ ) != 0;
      }
  
      void release() // nothrow
      {
          if( atomic_exchange_and_add( &use_count_, -1 ) == 1 )
          {
              dispose();
              weak_release();
          }
      }
  
      void weak_add_ref() // nothrow
      {
          atomic_increment( &weak_count_ );
      }
  
      void weak_release() // nothrow
      {
          if( atomic_exchange_and_add( &weak_count_, -1 ) == 1 )
          {
              destroy();
          }
      }
  
      long use_count() const // nothrow
      {
          return static_cast<int const volatile &>( use_count_ );
      }
  };
  
  } // namespace detail
  
  } // namespace autoboost
  
  #endif  // #ifndef AUTOBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CW_X86_HPP_INCLUDED
  