fusl/arch/x86_64/atomic_arch.h

#define a_cas a_cas
static inline int a_cas(volatile int* p, int t, int s) {
  __asm__ __volatile__("lock ; cmpxchg %3, %1"
                       : "=a"(t), "=m"(*p)
                       : "a"(t), "r"(s)
                       : "memory");
  return t;
}

#define a_cas_p a_cas_p
static inline void* a_cas_p(volatile void* p, void* t, void* s) {
  __asm__("lock ; cmpxchg %3, %1"
          : "=a"(t), "=m"(*(void* volatile*)p)
          : "a"(t), "r"(s)
          : "memory");
  return t;
}

#define a_swap a_swap
static inline int a_swap(volatile int* p, int v) {
  __asm__ __volatile__("xchg %0, %1" : "=r"(v), "=m"(*p) : "0"(v) : "memory");
  return v;
}

#define a_fetch_add a_fetch_add
static inline int a_fetch_add(volatile int* p, int v) {
  __asm__ __volatile__("lock ; xadd %0, %1"
                       : "=r"(v), "=m"(*p)
                       : "0"(v)
                       : "memory");
  return v;
}

#define a_and a_and
static inline void a_and(volatile int* p, int v) {
  __asm__ __volatile__("lock ; and %1, %0" : "=m"(*p) : "r"(v) : "memory");
}

#define a_or a_or
static inline void a_or(volatile int* p, int v) {
  __asm__ __volatile__("lock ; or %1, %0" : "=m"(*p) : "r"(v) : "memory");
}

#define a_and_64 a_and_64
static inline void a_and_64(volatile uint64_t* p, uint64_t v) {
  __asm__ __volatile("lock ; and %1, %0" : "=m"(*p) : "r"(v) : "memory");
}

#define a_or_64 a_or_64
static inline void a_or_64(volatile uint64_t* p, uint64_t v) {
  __asm__ __volatile__("lock ; or %1, %0" : "=m"(*p) : "r"(v) : "memory");
}

#define a_inc a_inc
static inline void a_inc(volatile int* p) {
  __asm__ __volatile__("lock ; incl %0" : "=m"(*p) : "m"(*p) : "memory");
}

#define a_dec a_dec
static inline void a_dec(volatile int* p) {
  __asm__ __volatile__("lock ; decl %0" : "=m"(*p) : "m"(*p) : "memory");
}

#define a_store a_store
static inline void a_store(volatile int* p, int x) {
  __asm__ __volatile__("mov %1, %0 ; lock ; orl $0,(%%rsp)"
                       : "=m"(*p)
                       : "r"(x)
                       : "memory");
}

#define a_barrier a_barrier
static inline void a_barrier() {
  __asm__ __volatile__("" : : : "memory");
}

#define a_pause a_pause
static inline void a_spin() {
  __asm__ __volatile__("pause" : : : "memory");
}

#define a_crash a_crash
static inline void a_crash() {
  __asm__ __volatile__("hlt" : : : "memory");
}

#define a_ctz_64 a_ctz_64
static inline int a_ctz_64(uint64_t x) {
  __asm__("bsf %1,%0" : "=r"(x) : "r"(x));
  return x;
}