宏定义
#define	MY_ATOMIC_MODE "gcc-x86" LOCK_prefix
#define	asm __asm__
#define	make_atomic_add_body(S) asm volatile (LOCK_prefix "; xadd %0, %1;" : "+r" (v) , "+m" (*a))
#define	make_atomic_fas_body(S) asm volatile ("xchg %0, %1;" : "+r" (v) , "+m" (*a))
#define	make_atomic_cas_body(S)
#define	make_atomic_load_body(S)
#define	make_atomic_store_body(S) asm volatile ("; xchg %0, %1;" : "+m" (*a), "+r" (v))

宏定义文档

#define asm __asm__

#define make_atomic_add_body ( S ) asm volatile (LOCK_prefix "; xadd %0, %1;" : "+r" (v) , "+m" (*a))

#define make_atomic_cas_body ( S )

值:

asm volatile (LOCK_prefix "; cmpxchg %3, %0; setz %2;"  \
               : "+m" (*a), "+a" (*cmp), "=q" (ret): "r" (set))

#define make_atomic_fas_body ( S ) asm volatile ("xchg %0, %1;" : "+r" (v) , "+m" (*a))

#define make_atomic_load_body ( S )

值:

ret=0;                          \
  asm volatile (LOCK_prefix "; cmpxchg %2, %0"          \
               : "+m" (*a), "+a" (ret): "r" (ret))

#define make_atomic_store_body ( S ) asm volatile ("; xchg %0, %1;" : "+m" (*a), "+r" (v))

#define MY_ATOMIC_MODE "gcc-x86" LOCK_prefix