/* Return the thread descriptor for the current thread.

   The contained asm must *not* be marked volatile since otherwise
   assignments like
	pthread_descr self = thread_self();
   do not get optimized away.  */
# define THREAD_SELF \
  ({ struct pthread *__self;						      \
     asm ("mov %%fs:%c1,%0" : "=r" (__self)				      \
	  : "i" (offsetof (struct pthread, header.self)));	 	      \
     __self;})