diff --git a/include/ntapi/bits/i386/nt_atomic_i386_asm__gcc.h b/include/ntapi/bits/i386/nt_atomic_i386_asm__gcc.h index 23260e9..1e9ed71 100644 --- a/include/ntapi/bits/i386/nt_atomic_i386_asm__gcc.h +++ b/include/ntapi/bits/i386/nt_atomic_i386_asm__gcc.h @@ -251,15 +251,25 @@ static __inline__ int64_t at_locked_cas_64( int64_t cmp, int64_t xchg) { - __atomic_compare_exchange_n( - dst, - &cmp, - xchg, - 0, - __ATOMIC_SEQ_CST, - __ATOMIC_SEQ_CST); - - return cmp; + unsigned edx, eax; + unsigned ecx, ebx; + + eax = (unsigned)cmp; + edx = (uint64_t)cmp >> 32; + + ebx = (unsigned)xchg; + ecx = (uint64_t)xchg >> 32; + + __asm__ volatile ( + "lock;" + "cmpxchg8b %6" + + : "=a" (eax), "=d" (edx) + : "a" (eax), "d" (edx), "b" (ebx), "c" (ecx), "m" (*dst) + : "memory"); + + + return ((int64_t)edx << 32) + eax; }