diff --git a/configure.ac b/configure.ac
index 58b662e1..f3adafb5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -283,6 +283,20 @@ if test x$have__builtin___clear_cache = xyes; then
 fi
 AC_MSG_RESULT([$have__builtin___clear_cache])
 
+AC_MSG_CHECKING([for __sync atomics])
+AC_LINK_IFELSE(
+  [AC_LANG_PROGRAM([[]], [[
+    __sync_bool_compare_and_swap((int *)0, 0, 1);
+    __sync_fetch_and_add((int *)0, 1);
+    ]])],
+  [have_sync_atomics=yes],
+  [have_sync_atomics=no])
+if test x$have_sync_atomics = xyes; then
+  AC_DEFINE([HAVE_SYNC_ATOMICS], [1],
+            [Defined if __sync atomics are available])
+fi
+AC_MSG_RESULT([$have_sync_atomics])
+
 CCASFLAGS="${CCASFLAGS} ${CPPFLAGS}"
 
 arch="$target_arch"
diff --git a/include/libunwind_i.h b/include/libunwind_i.h
index 15a79735..e0fb64b4 100644
--- a/include/libunwind_i.h
+++ b/include/libunwind_i.h
@@ -116,9 +116,10 @@ cmpxchg_ptr (void *addr, void *old, void *new)
 #   define HAVE_CMPXCHG
 #  endif
 # define HAVE_FETCH_AND_ADD
-#else
+#elif defined(HAVE_SYNC_ATOMICS) || defined(HAVE_IA64INTRIN_H)
 # ifdef HAVE_IA64INTRIN_H
 #  include <ia64intrin.h>
+# endif
 static inline int
 cmpxchg_ptr (void *addr, void *old, void *new)
 {
@@ -132,11 +133,10 @@ cmpxchg_ptr (void *addr, void *old, void *new)
   u.vp = addr;
   return __sync_bool_compare_and_swap(u.vlp, (long) old, (long) new);
 }
-#  define fetch_and_add1(_ptr)		__sync_fetch_and_add(_ptr, 1)
-#  define fetch_and_add(_ptr, value)	__sync_fetch_and_add(_ptr, value)
-#  define HAVE_CMPXCHG
-#  define HAVE_FETCH_AND_ADD
-# endif
+# define fetch_and_add1(_ptr)		__sync_fetch_and_add(_ptr, 1)
+# define fetch_and_add(_ptr, value)	__sync_fetch_and_add(_ptr, value)
+# define HAVE_CMPXCHG
+# define HAVE_FETCH_AND_ADD
 #endif
 #define atomic_read(ptr)	(*(ptr))