PowerPC: Sync pthread_once with default implementation

This patch removes the arch specific powerpc implementation and instead
uses the linux default one.  Although the current powerpc implementation
already constains the required memory barriers for correct
initialization, the default implementation shows a better performance on
newer chips.

diff --git a/ChangeLog b/ChangeLog
index 9f67a67..23cded5 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2014-04-17  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
 
+       * nptl/sysdeps/unix/sysv/linux/powerpc/pthread_once.c: Remove file.
+
+2014-04-17  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
+
        * sysdeps/powerpc/fpu/fenv_private.h
        (libc_feholdexcept_setroundl_ctx): Define to
        libc_feholdexcept_setround_ppc_ctx.

diff --git a/nptl/sysdeps/unix/sysv/linux/powerpc/pthread_once.c b/nptl/sysdeps/unix/sysv/linux/powerpc/pthread_once.c
deleted file mode 100644 (file)
index e925299..0000000
--- a/nptl/sysdeps/unix/sysv/linux/powerpc/pthread_once.c
+++ /dev/null
@@ -1,110 +0,0 @@
-/* Copyright (C) 2003-2014 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.         See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include "pthreadP.h"
-#include <lowlevellock.h>
-
-
-unsigned long int __fork_generation attribute_hidden;
-
-
-static void
-clear_once_control (void *arg)
-{
-  pthread_once_t *once_control = (pthread_once_t *) arg;
-
-  __asm __volatile (__lll_rel_instr);
-  *once_control = 0;
-  lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
-}
-
-
-int
-__pthread_once (pthread_once_t *once_control, void (*init_routine) (void))
-{
-  for (;;)
-    {
-      int oldval;
-      int newval;
-      int tmp;
-
-      /* Pseudo code:
-        newval = __fork_generation | 1;
-        oldval = *once_control;
-        if ((oldval & 2) == 0)
-          *once_control = newval;
-        Do this atomically with an acquire barrier.
-      */
-      newval = __fork_generation | 1;
-      __asm __volatile ("1:    lwarx   %0,0,%3" MUTEX_HINT_ACQ "\n"
-                       "       andi.   %1,%0,2\n"
-                       "       bne     2f\n"
-                       "       stwcx.  %4,0,%3\n"
-                       "       bne     1b\n"
-                       "2:     " __lll_acq_instr
-                       : "=&r" (oldval), "=&r" (tmp), "=m" (*once_control)
-                       : "r" (once_control), "r" (newval), "m" (*once_control)
-                       : "cr0");
-
-      /* Check if the initializer has already been done.  */
-      if ((oldval & 2) != 0)
-       return 0;
-
-      /* Check if another thread already runs the initializer. */
-      if ((oldval & 1) == 0)
-       break;
-
-      /* Check whether the initializer execution was interrupted by a fork.  */
-      if (oldval != newval)
-       break;
-
-      /* Same generation, some other thread was faster. Wait.  */
-      lll_futex_wait (once_control, oldval, LLL_PRIVATE);
-    }
-
-
-  /* This thread is the first here.  Do the initialization.
-     Register a cleanup handler so that in case the thread gets
-     interrupted the initialization can be restarted.  */
-  pthread_cleanup_push (clear_once_control, once_control);
-
-  init_routine ();
-
-  pthread_cleanup_pop (0);
-
-
-  /* Add one to *once_control to take the bottom 2 bits from 01 to 10.
-     A release barrier is needed to ensure memory written by init_routine
-     is seen in other threads before *once_control changes.  */
-  int tmp;
-  __asm __volatile (__lll_rel_instr "\n"
-                   "1: lwarx   %0,0,%2" MUTEX_HINT_REL "\n"
-                   "   addi    %0,%0,1\n"
-                   "   stwcx.  %0,0,%2\n"
-                   "   bne-    1b"
-                   : "=&b" (tmp), "=m" (*once_control)
-                   : "r" (once_control), "m" (*once_control)
-                   : "cr0");
-
-  /* Wake up all other threads.  */
-  lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
-
-  return 0;
-}
-weak_alias (__pthread_once, pthread_once)
-hidden_def (__pthread_once)