Chris@102: /*
Chris@102:  * Distributed under the Boost Software License, Version 1.0.
Chris@102:  * (See accompanying file LICENSE_1_0.txt or copy at
Chris@102:  * http://www.boost.org/LICENSE_1_0.txt)
Chris@102:  *
Chris@102:  * Copyright (c) 2009 Helge Bahmann
Chris@102:  * Copyright (c) 2012 Tim Blechmann
Chris@102:  * Copyright (c) 2014 Andrey Semashev
Chris@102:  */
Chris@102: /*!
Chris@102:  * \file   atomic/detail/ops_gcc_x86.hpp
Chris@102:  *
Chris@102:  * This header contains implementation of the \c operations template.
Chris@102:  */
Chris@102: 
Chris@102: #ifndef BOOST_ATOMIC_DETAIL_OPS_GCC_X86_HPP_INCLUDED_
Chris@102: #define BOOST_ATOMIC_DETAIL_OPS_GCC_X86_HPP_INCLUDED_
Chris@102: 
Chris@102: #include <boost/memory_order.hpp>
Chris@102: #include <boost/atomic/detail/config.hpp>
Chris@102: #include <boost/atomic/detail/storage_type.hpp>
Chris@102: #include <boost/atomic/detail/operations_fwd.hpp>
Chris@102: #include <boost/atomic/capabilities.hpp>
Chris@102: #if defined(BOOST_ATOMIC_DETAIL_X86_HAS_CMPXCHG8B) || defined(BOOST_ATOMIC_DETAIL_X86_HAS_CMPXCHG16B)
Chris@102: #include <boost/atomic/detail/ops_gcc_x86_dcas.hpp>
Chris@102: #include <boost/atomic/detail/ops_cas_based.hpp>
Chris@102: #endif
Chris@102: 
Chris@102: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@102: #pragma once
Chris@102: #endif
Chris@102: 
Chris@102: #if defined(__x86_64__)
Chris@102: #define BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER "rdx"
Chris@102: #else
Chris@102: #define BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER "edx"
Chris@102: #endif
Chris@102: 
Chris@102: namespace boost {
Chris@102: namespace atomics {
Chris@102: namespace detail {
Chris@102: 
Chris@102: struct gcc_x86_operations_base
Chris@102: {
Chris@102:     static BOOST_FORCEINLINE void fence_before(memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         if ((order & memory_order_release) != 0)
Chris@102:             __asm__ __volatile__ ("" ::: "memory");
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void fence_after(memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         if ((order & memory_order_acquire) != 0)
Chris@102:             __asm__ __volatile__ ("" ::: "memory");
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: template< typename T, typename Derived >
Chris@102: struct gcc_x86_operations :
Chris@102:     public gcc_x86_operations_base
Chris@102: {
Chris@102:     typedef T storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void store(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         if (order != memory_order_seq_cst)
Chris@102:         {
Chris@102:             fence_before(order);
Chris@102:             storage = v;
Chris@102:             fence_after(order);
Chris@102:         }
Chris@102:         else
Chris@102:         {
Chris@102:             Derived::exchange(storage, v, order);
Chris@102:         }
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type load(storage_type const volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type v = storage;
Chris@102:         fence_after(order);
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return Derived::fetch_add(storage, -v, order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_weak(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return Derived::compare_exchange_strong(storage, expected, desired, success_order, failure_order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return !!Derived::exchange(storage, (storage_type)1, order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         store(storage, (storage_type)0, order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool is_lock_free(storage_type const volatile&) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return true;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 1u, Signed > :
Chris@102:     public gcc_x86_operations< typename make_storage_type< 1u, Signed >::type, operations< 1u, Signed > >
Chris@102: {
Chris@102:     typedef gcc_x86_operations< typename make_storage_type< 1u, Signed >::type, operations< 1u, Signed > > base_type;
Chris@102:     typedef typename base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; xaddb %0, %1"
Chris@102:             : "+q" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "xchgb %0, %1"
Chris@102:             : "+q" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_strong(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type previous = expected;
Chris@102:         bool success;
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; cmpxchgb %3, %1\n\t"
Chris@102:             "sete %2"
Chris@102:             : "+a" (previous), "+m" (storage), "=q" (success)
Chris@102:             : "q" (desired)
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         expected = previous;
Chris@102:         return success;
Chris@102:     }
Chris@102: 
Chris@102: #define BOOST_ATOMIC_DETAIL_CAS_LOOP(op, argument, result)\
Chris@102:     __asm__ __volatile__\
Chris@102:     (\
Chris@102:         "xor %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER ", %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER "\n\t"\
Chris@102:         ".align 16\n\t"\
Chris@102:         "1: movb %[arg], %%dl\n\t"\
Chris@102:         op " %%al, %%dl\n\t"\
Chris@102:         "lock; cmpxchgb %%dl, %[storage]\n\t"\
Chris@102:         "jne 1b"\
Chris@102:         : [res] "+a" (result), [storage] "+m" (storage)\
Chris@102:         : [arg] "q" (argument)\
Chris@102:         : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER, "memory"\
Chris@102:     )
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("andb", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("orb", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("xorb", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102: #undef BOOST_ATOMIC_DETAIL_CAS_LOOP
Chris@102: };
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 2u, Signed > :
Chris@102:     public gcc_x86_operations< typename make_storage_type< 2u, Signed >::type, operations< 2u, Signed > >
Chris@102: {
Chris@102:     typedef gcc_x86_operations< typename make_storage_type< 2u, Signed >::type, operations< 2u, Signed > > base_type;
Chris@102:     typedef typename base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; xaddw %0, %1"
Chris@102:             : "+q" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "xchgw %0, %1"
Chris@102:             : "+q" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_strong(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type previous = expected;
Chris@102:         bool success;
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; cmpxchgw %3, %1\n\t"
Chris@102:             "sete %2"
Chris@102:             : "+a" (previous), "+m" (storage), "=q" (success)
Chris@102:             : "q" (desired)
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         expected = previous;
Chris@102:         return success;
Chris@102:     }
Chris@102: 
Chris@102: #define BOOST_ATOMIC_DETAIL_CAS_LOOP(op, argument, result)\
Chris@102:     __asm__ __volatile__\
Chris@102:     (\
Chris@102:         "xor %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER ", %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER "\n\t"\
Chris@102:         ".align 16\n\t"\
Chris@102:         "1: movw %[arg], %%dx\n\t"\
Chris@102:         op " %%ax, %%dx\n\t"\
Chris@102:         "lock; cmpxchgw %%dx, %[storage]\n\t"\
Chris@102:         "jne 1b"\
Chris@102:         : [res] "+a" (result), [storage] "+m" (storage)\
Chris@102:         : [arg] "q" (argument)\
Chris@102:         : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER, "memory"\
Chris@102:     )
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("andw", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("orw", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("xorw", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102: #undef BOOST_ATOMIC_DETAIL_CAS_LOOP
Chris@102: };
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 4u, Signed > :
Chris@102:     public gcc_x86_operations< typename make_storage_type< 4u, Signed >::type, operations< 4u, Signed > >
Chris@102: {
Chris@102:     typedef gcc_x86_operations< typename make_storage_type< 4u, Signed >::type, operations< 4u, Signed > > base_type;
Chris@102:     typedef typename base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; xaddl %0, %1"
Chris@102:             : "+r" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "xchgl %0, %1"
Chris@102:             : "+r" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_strong(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type previous = expected;
Chris@102:         bool success;
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; cmpxchgl %3, %1\n\t"
Chris@102:             "sete %2"
Chris@102:             : "+a" (previous), "+m" (storage), "=q" (success)
Chris@102:             : "r" (desired)
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         expected = previous;
Chris@102:         return success;
Chris@102:     }
Chris@102: 
Chris@102: #define BOOST_ATOMIC_DETAIL_CAS_LOOP(op, argument, result)\
Chris@102:     __asm__ __volatile__\
Chris@102:     (\
Chris@102:         "xor %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER ", %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER "\n\t"\
Chris@102:         ".align 16\n\t"\
Chris@102:         "1: movl %[arg], %%edx\n\t"\
Chris@102:         op " %%eax, %%edx\n\t"\
Chris@102:         "lock; cmpxchgl %%edx, %[storage]\n\t"\
Chris@102:         "jne 1b"\
Chris@102:         : [res] "+a" (result), [storage] "+m" (storage)\
Chris@102:         : [arg] "r" (argument)\
Chris@102:         : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER, "memory"\
Chris@102:     )
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("andl", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("orl", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("xorl", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102: #undef BOOST_ATOMIC_DETAIL_CAS_LOOP
Chris@102: };
Chris@102: 
Chris@102: #if defined(BOOST_ATOMIC_DETAIL_X86_HAS_CMPXCHG8B)
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 8u, Signed > :
Chris@102:     public cas_based_operations< gcc_dcas_x86< Signed > >
Chris@102: {
Chris@102: };
Chris@102: 
Chris@102: #elif defined(__x86_64__)
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 8u, Signed > :
Chris@102:     public gcc_x86_operations< typename make_storage_type< 8u, Signed >::type, operations< 8u, Signed > >
Chris@102: {
Chris@102:     typedef gcc_x86_operations< typename make_storage_type< 8u, Signed >::type, operations< 8u, Signed > > base_type;
Chris@102:     typedef typename base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; xaddq %0, %1"
Chris@102:             : "+r" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "xchgq %0, %1"
Chris@102:             : "+r" (v), "+m" (storage)
Chris@102:             :
Chris@102:             : "memory"
Chris@102:         );
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_strong(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type previous = expected;
Chris@102:         bool success;
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "lock; cmpxchgq %3, %1\n\t"
Chris@102:             "sete %2"
Chris@102:             : "+a" (previous), "+m" (storage), "=q" (success)
Chris@102:             : "r" (desired)
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "memory"
Chris@102:         );
Chris@102:         expected = previous;
Chris@102:         return success;
Chris@102:     }
Chris@102: 
Chris@102: #define BOOST_ATOMIC_DETAIL_CAS_LOOP(op, argument, result)\
Chris@102:     __asm__ __volatile__\
Chris@102:     (\
Chris@102:         "xor %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER ", %%" BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER "\n\t"\
Chris@102:         ".align 16\n\t"\
Chris@102:         "1: movq %[arg], %%rdx\n\t"\
Chris@102:         op " %%rax, %%rdx\n\t"\
Chris@102:         "lock; cmpxchgq %%rdx, %[storage]\n\t"\
Chris@102:         "jne 1b"\
Chris@102:         : [res] "+a" (result), [storage] "+m" (storage)\
Chris@102:         : [arg] "r" (argument)\
Chris@102:         : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER, "memory"\
Chris@102:     )
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("andq", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("orq", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type res = storage;
Chris@102:         BOOST_ATOMIC_DETAIL_CAS_LOOP("xorq", v, res);
Chris@102:         return res;
Chris@102:     }
Chris@102: 
Chris@102: #undef BOOST_ATOMIC_DETAIL_CAS_LOOP
Chris@102: };
Chris@102: 
Chris@102: #endif
Chris@102: 
Chris@102: #if defined(BOOST_ATOMIC_DETAIL_X86_HAS_CMPXCHG16B)
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 16u, Signed > :
Chris@102:     public cas_based_operations< gcc_dcas_x86_64< Signed > >
Chris@102: {
Chris@102: };
Chris@102: 
Chris@102: #endif // defined(BOOST_ATOMIC_DETAIL_X86_HAS_CMPXCHG16B)
Chris@102: 
Chris@102: BOOST_FORCEINLINE void thread_fence(memory_order order) BOOST_NOEXCEPT
Chris@102: {
Chris@102:     if (order == memory_order_seq_cst)
Chris@102:     {
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102: #if defined(__x86_64__) || defined(__SSE2__)
Chris@102:             "mfence\n"
Chris@102: #else
Chris@102:             "lock; addl $0, (%%esp)\n"
Chris@102: #endif
Chris@102:             ::: "memory"
Chris@102:         );
Chris@102:     }
Chris@102:     else if ((order & (memory_order_acquire | memory_order_release)) != 0)
Chris@102:     {
Chris@102:         __asm__ __volatile__ ("" ::: "memory");
Chris@102:     }
Chris@102: }
Chris@102: 
Chris@102: BOOST_FORCEINLINE void signal_fence(memory_order order) BOOST_NOEXCEPT
Chris@102: {
Chris@102:     if (order != memory_order_relaxed)
Chris@102:         __asm__ __volatile__ ("" ::: "memory");
Chris@102: }
Chris@102: 
Chris@102: } // namespace detail
Chris@102: } // namespace atomics
Chris@102: } // namespace boost
Chris@102: 
Chris@102: #undef BOOST_ATOMIC_DETAIL_TEMP_CAS_REGISTER
Chris@102: 
Chris@102: #endif // BOOST_ATOMIC_DETAIL_OPS_GCC_X86_HPP_INCLUDED_