nptl: Move elision implementations into libc

The elision interfaces are closely aligned between the targets that
implement them, so declare them in the generic <lowlevellock.h>
file.

Empty .c stubs are provided, so that fewer makefile updates
under sysdeps are needed.  Also simplify initialization via
__libc_early_init.

The symbols __lll_clocklock_elision, __lll_lock_elision,
__lll_trylock_elision, __lll_unlock_elision, __pthread_force_elision
move into libc.  For the time being, non-hidden references are used
from libpthread to access them, but once that part of libpthread
is moved into libc, hidden symbols will be used again.  (Hidden
references seem desirable to reduce the likelihood of transactions
aborts.)

1 files changed, 1 insertions, 14 deletions

diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
index 319658adc4..f0de7b7fd6 100644
--- a/nptl/pthread_mutex_lock.c
+++ b/nptl/pthread_mutex_lock.c
@@ -27,15 +27,6 @@
 #include <futex-internal.h>
 #include <stap-probe.h>
 
-#ifndef lll_lock_elision
-#define lll_lock_elision(lock, try_lock, private)	({ \
-      lll_lock (lock, private); 0; })
-#endif
-
-#ifndef lll_trylock_elision
-#define lll_trylock_elision(a,t) lll_trylock(a)
-#endif
-
 /* Some of the following definitions differ when pthread_mutex_cond_lock.c
    includes this file.  */
 #ifndef LLL_MUTEX_LOCK
@@ -52,10 +43,6 @@
 		   PTHREAD_MUTEX_PSHARED (mutex))
 #endif
 
-#ifndef FORCE_ELISION
-#define FORCE_ELISION(m, s)
-#endif
-
 static int __pthread_mutex_lock_full (pthread_mutex_t *mutex)
      __attribute_noinline__;
 
@@ -80,7 +67,7 @@ __pthread_mutex_lock (pthread_mutex_t *mutex)
       LLL_MUTEX_LOCK (mutex);
       assert (mutex->__data.__owner == 0);
     }
-#ifdef HAVE_ELISION
+#if ENABLE_ELISION_SUPPORT
   else if (__glibc_likely (type == PTHREAD_MUTEX_TIMED_ELISION_NP))
     {
   elision: __attribute__((unused))