66   STATIC_ASSERT(8 == sizeof(D));
  67 
  68   D rv;
  69   __asm__ volatile(
  70     "1: \n\t"
  71     " ldx    [%2], %%o2\n\t"
  72     " add    %1, %%o2, %%o3\n\t"
  73     " casx   [%2], %%o2, %%o3\n\t"
  74     " cmp    %%o2, %%o3\n\t"
  75     " bne    %%xcc, 1b\n\t"
  76     "  nop\n\t"
  77     " add    %1, %%o2, %0\n\t"
  78     : "=r" (rv)
  79     : "r" (add_value), "r" (dest)
  80     : "memory", "o2", "o3");
  81   return rv;
  82 }
  83 
  84 template<>
  85 template<typename T>
  86 inline T Atomic::PlatformXchg<4>::operator()(T exchange_value,
  87                                              T volatile* dest,
  88                                              atomic_memory_order order) const {
  89   STATIC_ASSERT(4 == sizeof(T));
  90   T rv = exchange_value;
  91   __asm__ volatile(
  92     " swap   [%2],%1\n\t"
  93     : "=r" (rv)
  94     : "0" (exchange_value) /* we use same register as for return value */, "r" (dest)
  95     : "memory");
  96   return rv;
  97 }
  98 
  99 template<>
 100 template<typename T>
 101 inline T Atomic::PlatformXchg<8>::operator()(T exchange_value,
 102                                              T volatile* dest,
 103                                              atomic_memory_order order) const {
 104   STATIC_ASSERT(8 == sizeof(T));
 105   T rv = exchange_value;
 106   __asm__ volatile(
 107     "1:\n\t"
 108     " mov    %1, %%o3\n\t"
 109     " ldx    [%2], %%o2\n\t"
 110     " casx   [%2], %%o2, %%o3\n\t"
 111     " cmp    %%o2, %%o3\n\t"
 112     " bne    %%xcc, 1b\n\t"
 113     "  nop\n\t"
 114     " mov    %%o2, %0\n\t"
 115     : "=r" (rv)
 116     : "r" (exchange_value), "r" (dest)
 117     : "memory", "o2", "o3");
 118   return rv;
 119 }
 120 
 121 // No direct support for cmpxchg of bytes; emulate using int.
 122 template<>

  66   STATIC_ASSERT(8 == sizeof(D));
  67 
  68   D rv;
  69   __asm__ volatile(
  70     "1: \n\t"
  71     " ldx    [%2], %%o2\n\t"
  72     " add    %1, %%o2, %%o3\n\t"
  73     " casx   [%2], %%o2, %%o3\n\t"
  74     " cmp    %%o2, %%o3\n\t"
  75     " bne    %%xcc, 1b\n\t"
  76     "  nop\n\t"
  77     " add    %1, %%o2, %0\n\t"
  78     : "=r" (rv)
  79     : "r" (add_value), "r" (dest)
  80     : "memory", "o2", "o3");
  81   return rv;
  82 }
  83 
  84 template<>
  85 template<typename T>
  86 inline T Atomic::PlatformXchg<4>::operator()(T volatile* dest,
  87                                              T exchange_value,
  88                                              atomic_memory_order order) const {
  89   STATIC_ASSERT(4 == sizeof(T));
  90   T rv = exchange_value;
  91   __asm__ volatile(
  92     " swap   [%2],%1\n\t"
  93     : "=r" (rv)
  94     : "0" (exchange_value) /* we use same register as for return value */, "r" (dest)
  95     : "memory");
  96   return rv;
  97 }
  98 
  99 template<>
 100 template<typename T>
 101 inline T Atomic::PlatformXchg<8>::operator()(T volatile* dest,
 102                                              T exchange_value,
 103                                              atomic_memory_order order) const {
 104   STATIC_ASSERT(8 == sizeof(T));
 105   T rv = exchange_value;
 106   __asm__ volatile(
 107     "1:\n\t"
 108     " mov    %1, %%o3\n\t"
 109     " ldx    [%2], %%o2\n\t"
 110     " casx   [%2], %%o2, %%o3\n\t"
 111     " cmp    %%o2, %%o3\n\t"
 112     " bne    %%xcc, 1b\n\t"
 113     "  nop\n\t"
 114     " mov    %%o2, %0\n\t"
 115     : "=r" (rv)
 116     : "r" (exchange_value), "r" (dest)
 117     : "memory", "o2", "o3");
 118   return rv;
 119 }
 120 
 121 // No direct support for cmpxchg of bytes; emulate using int.
 122 template<>