求一段AT&T一段内联汇编问题

Question

/* Conditionally execute fence after interlocked instruction. */
static INLINE void
AtomicEpilogue(void)
{
#ifdef ATOMIC_USE_FENCE
#ifdef VMM
      /* The monitor conditionally patches out the lfence when not needed.*/
      /* Construct a MonitorPatchTextEntry in the .patchtext section. */
   asm volatile ("1:nt"
                 "lfencent"
                 "2:nt"
                 ".pushsection .patchtextnt"
                 ".quad 1bnt"
                 ".quad 2bnt"
                 ".popsectionnt" ::: "memory");
#else
   if (UNLIKELY(AtomicUseFence)) {
      asm volatile ("lfence" ::: "memory");
   }
#endif
#endif

上面这段代码完全看不懂啥意思

Answer 1

info gcc->C Extensions->Extended Asm
info as->Pseudo Ops
也可以看看
http://blog.chinaunix.net/u/17660/showart_259729.html

Answer 2

info gcc->C Extensions->Extended Asm
info as->Pseudo Ops
也可以看看
http://blog.chinaunix.net/u/17660/showart_259729.html