Add support for __sync builtin compare and swap on 128-bit values

config/opal_config_asm.m4

@@ -19,6 +19,23 @@ dnl $HEADER$
 dnl
 
 
+AC_DEFUN([OPAL_CHECK_SYNC_BUILTIN_CSWAP_INT128], [
+  AC_MSG_CHECKING([for __sync builtin atomic compare-and-swap on 128-bit values])
+
+  OPAL_VAR_SCOPE_PUSH([sync_bool_compare_and_swap_128_result])
+
+  AC_TRY_COMPILE([], [__int128 x = 0; __sync_bool_compare_and_swap (&x, 0, 1);],
+    [AC_MSG_RESULT([yes])
+     sync_bool_compare_and_swap_128_result=1],
+    [AC_MSG_RESULT([no])
+     sync_bool_compare_and_swap_128_result=0])
+
+  AC_DEFINE_UNQUOTED([OPAL_HAVE_SYNC_BUILTIN_CSWAP_INT128], [$sync_bool_compare_and_swap_128_result],
+	[Whether the __sync builtin atomic compare and swap supports 128-bit values])
+
+  OPAL_VAR_SCOPE_POP
+])
+
 AC_DEFUN([OPAL_CHECK_SYNC_BUILTINS], [
   AC_MSG_CHECKING([for __sync builtin atomics])
 
@@ -577,7 +594,6 @@ AC_DEFUN([OPAL_CHECK_CMPXCHG16B],[
     OPAL_VAR_SCOPE_POP
 ])dnl
 
-
 dnl #################################################################
 dnl
 dnl OPAL_CHECK_INLINE_GCC
@@ -789,6 +805,7 @@ AC_DEFUN([OPAL_CONFIG_ASM],[
          [AC_MSG_ERROR([__sync builtin atomics requested but not found.])])
        AC_DEFINE([OPAL_C_GCC_INLINE_ASSEMBLY], [1],
          [Whether C compiler supports GCC style inline assembly])
+       OPAL_CHECK_SYNC_BUILTIN_CSWAP_INT128
     elif test "$enable_osx_builtin_atomics" = "yes" ; then
 	   AC_CHECK_HEADER([libkern/OSAtomic.h],[opal_cv_asm_builtin="BUILTIN_OSX"],
 	    [AC_MSG_ERROR([OSX builtin atomics requested but not found.])])

opal/include/opal/sys/sync_builtin/atomic.h

@@ -1,3 +1,4 @@
+/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
 /*
  * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
  *                         University Research and Technology
@@ -10,6 +11,8 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2011      Sandia National Laboratories. All rights reserved.
+ * Copyright (c) 2014      Los Alamos National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  * 
  * Additional copyrights may follow
@@ -106,6 +109,17 @@ static inline int opal_atomic_cmpset_64( volatile int64_t *addr,
     return __sync_bool_compare_and_swap(addr, oldval, newval);
 }
 
+#if OPAL_HAVE_SYNC_BUILTIN_CSWAP_INT128
+static inline int opal_atomic_cmpset_128 (volatile opal_int128_t *addr,
+                                          opal_int128_t oldval, opal_int128_t newval)
+{
+    return __sync_bool_compare_and_swap(addr, oldval, newval);
+}
+
+#define OPAL_HAVE_ATOMIC_CMPSET_128 1
+
+#endif
+
 #define OPAL_HAVE_ATOMIC_MATH_64 1
 #define OPAL_HAVE_ATOMIC_ADD_64 1
 static inline int64_t opal_atomic_add_64(volatile int64_t *addr, int64_t delta)