GCC 之 cas和cas2
cas.h
#if defined(__GNUC__)
#if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP)
#define CAS __sync_bool_compare_and_swap
#endif//CAS2
#if defined(__x86_64__)#if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_16)
#define CAS2(p,o,n) __sync_bool_compare_and_swap_16((long long *)(p), *(long long *)(&o), *(long long *)(&n))
#else
#define CAS2(p,o,n) CAS2_IMPL((long long *)(p), (long *)(&o), (long *)(&n))
inline
bool CAS2_IMPL(long *addr,
long * old_value,
long * new_value)
{
bool ret;
__asm__ __volatile__(
"lock cmpxchg16b %1;\n"
"sete %0;\n"
:"=m"(ret),"+m" (*(volatile long long *) (addr))
:"a" (old_value[0]), "d" (old_value[1]), "b" (new_value[0]), "c" (new_value[1]));
return ret;
}
#endif#else
#if !defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8)
#define CAS2(p,o,n) __sync_bool_compare_and_swap_8((long long *)(p), *(long long *)(&o), *(long long *)(&n))
#else
#define CAS2(p,o,n) CAS2_IMPL((long long *)(p), (long *)(&o), (long *)(&n))
inline
bool CAS2_IMPL(long long *addr,
long * old_value,
long * new_value)
{
bool ret;
__asm__ __volatile__(
"lock cmpxchg8b %1;\n"
"sete %0;\n"
:"=m"(ret),"+m" (*(volatile long long *) (addr))
:"a" (old_value[0]), "d" (old_value[1]), "b" (new_value[0]), "c" (new_value[1]));
return ret;
}#endif
#endif //CAS2
#endif //__GNUC__