#ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED

 #define BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED

 //

 //  detail/sp_counted_base_gcc_ia64.hpp - g++ on IA64

 //

 //  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.

 //  Copyright 2004-2006 Peter Dimov

 //  Copyright 2005 Ben Hutchings

 //

 //  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

 //

 #include <typeinfo>

 namespace boost

 {

 namespace detail

 {

 inline void atomic_increment( int * pw )

 {

     // ++*pw;

     int tmp;

     // No barrier is required here but fetchadd always has an acquire or

     // release barrier associated with it.  We choose release as it should be

     // cheaper.

     __asm__ ("fetchadd4.rel %0=%1,1" :

          "=r"(tmp), "=m"(*pw) :

          "m"( *pw ));

 }

 inline int atomic_decrement( int * pw )

 {

     // return --*pw;

     int rv;

     __asm__ ("     fetchadd4.rel %0=%1,-1 ;; \n"

              "     cmp.eq        p7,p0=1,%0 ;; \n"

              "(p7) ld4.acq       %0=%1    " :

              "=&r"(rv), "=m"(*pw) :

              "m"( *pw ) :

              "p7");

     return rv;

 }

 inline int atomic_conditional_increment( int * pw )

 {

     // if( *pw != 0 ) ++*pw;

     // return *pw;

     int rv, tmp, tmp2;

     __asm__ ("0:   ld4          %0=%3           ;; \n"

          "     cmp.eq       p7,p0=0,%0        ;; \n"

          "(p7) br.cond.spnt 1f                \n"

          "     mov          ar.ccv=%0         \n"

          "     add          %1=1,%0           ;; \n"

          "     cmpxchg4.acq %2=%3,%1,ar.ccv ;; \n"

          "     cmp.ne       p7,p0=%0,%2       ;; \n"

          "(p7) br.cond.spnt 0b                \n"

          "     mov          %0=%1             ;; \n"

          "1:" : 

          "=&r"(rv), "=&r"(tmp), "=&r"(tmp2), "=m"(*pw) :

          "m"( *pw ) :

          "ar.ccv", "p7");

     return rv;

 }

 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( std::type_info const & ti ) = 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_decrement( &use_count_ ) == 0 )

         {

             dispose();

             weak_release();

         }

     }

     void weak_add_ref() // nothrow

     {

         atomic_increment( &weak_count_ );

     }

     void weak_release() // nothrow

     {

         if( atomic_decrement( &weak_count_ ) == 0 )

         {

             destroy();

         }

     }

     long use_count() const // nothrow

     {

         return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here

     }

 };

 } // namespace detail

 } // namespace boost

 #endif  // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED