1 /*
2  * Distributed under the Boost Software License, Version 1.0.
3  *    (See accompanying file LICENSE_1_0.txt or copy at
4  *          http://www.boost.org/LICENSE_1_0.txt)
5  *
6  * (C) Copyright 2013 Tim Blechmann
7  * (C) Copyright 2013 Andrey Semashev
8  */
9 
10 #ifndef BOOST_ATOMIC_DETAIL_PAUSE_HPP_INCLUDED_
11 #define BOOST_ATOMIC_DETAIL_PAUSE_HPP_INCLUDED_
12 
13 #include <boost/atomic/detail/config.hpp>
14 
15 #ifdef BOOST_HAS_PRAGMA_ONCE
16 #pragma once
17 #endif
18 
19 #if defined(_MSC_VER) && (defined(_M_AMD64) || defined(_M_IX86))
20 extern "C" void _mm_pause(void);
21 #if defined(BOOST_MSVC)
22 #pragma intrinsic(_mm_pause)
23 #endif
24 #endif
25 
26 namespace boost {
27 namespace atomics {
28 namespace detail {
29 
pause()30 BOOST_FORCEINLINE void pause() BOOST_NOEXCEPT
31 {
32 #if defined(_MSC_VER) && (defined(_M_AMD64) || defined(_M_IX86))
33     _mm_pause();
34 #elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
35     __asm__ __volatile__("pause;");
36 #endif
37 }
38 
39 } // namespace detail
40 } // namespace atomics
41 } // namespace boost
42 
43 #endif // BOOST_ATOMIC_DETAIL_PAUSE_HPP_INCLUDED_
44