Imported gcc-4.4.3

[msp430-gcc.git] / libgomp / config / linux / ptrlock.c

diff --git a/libgomp/config/linux/ptrlock.c b/libgomp/config/linux/ptrlock.c
new file mode 100644 (file)
index 0000000..7c2ad61
--- /dev/null
+++ b/libgomp/config/linux/ptrlock.c
@@ -0,0 +1,67 @@
+/* Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+   Contributed by Jakub Jelinek <jakub@redhat.com>.
+
+   This file is part of the GNU OpenMP Library (libgomp).
+
+   Libgomp is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   Libgomp 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 General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This is a Linux specific implementation of a mutex synchronization
+   mechanism for libgomp.  This type is private to the library.  This
+   implementation uses atomic instructions and the futex syscall.  */
+
+#include <endian.h>
+#include <limits.h>
+#include "wait.h"
+
+void *
+gomp_ptrlock_get_slow (gomp_ptrlock_t *ptrlock)
+{
+  int *intptr;
+  __sync_bool_compare_and_swap (ptrlock, 1, 2);
+
+  /* futex works on ints, not pointers.
+     But a valid work share pointer will be at least
+     8 byte aligned, so it is safe to assume the low
+     32-bits of the pointer won't contain values 1 or 2.  */
+  __asm volatile ("" : "=r" (intptr) : "0" (ptrlock));
+#if __BYTE_ORDER == __BIG_ENDIAN
+  if (sizeof (*ptrlock) > sizeof (int))
+    intptr += (sizeof (*ptrlock) / sizeof (int)) - 1;
+#endif
+  do
+    do_wait (intptr, 2);
+  while (*intptr == 2);
+  __asm volatile ("" : : : "memory");
+  return *ptrlock;
+}
+
+void
+gomp_ptrlock_set_slow (gomp_ptrlock_t *ptrlock, void *ptr)
+{
+  int *intptr;
+
+  *ptrlock = ptr;
+  __asm volatile ("" : "=r" (intptr) : "0" (ptrlock));
+#if __BYTE_ORDER == __BIG_ENDIAN
+  if (sizeof (*ptrlock) > sizeof (int))
+    intptr += (sizeof (*ptrlock) / sizeof (int)) - 1;
+#endif
+  futex_wake (intptr, INT_MAX);
+}