diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 96da24af999..7e5513a89c1 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,4 +1,8 @@
-2007-05-23  Steve Ellcey  <sje@cup.hp.com>
+2007-05-24  Paolo Carlini  <pcarlini@suse.de>
+
+	* include/ext/concurrence.h: Use __GCC_HAVE_SYNC_COMPARE_AND_SWAP_*.
+
+2007-05-24  Steve Ellcey  <sje@cup.hp.com>
 
 	* Makefile.in: Regenerate.
 	* configure: Regenerate.
diff --git a/libstdc++-v3/include/ext/concurrence.h b/libstdc++-v3/include/ext/concurrence.h
index 6efb2a6be08..de4934c63c5 100644
--- a/libstdc++-v3/include/ext/concurrence.h
+++ b/libstdc++-v3/include/ext/concurrence.h
@@ -53,9 +53,8 @@ _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
   // the current configuration.
   static const _Lock_policy __default_lock_policy = 
 #ifdef __GTHREADS
-  // NB: This macro doesn't actually exist yet in the compiler, but is
-  // set somewhat haphazardly at configure time.
-#ifdef _GLIBCXX_ATOMIC_BUILTINS
+#if (defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) \
+     && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4))
   _S_atomic;
 #else
   _S_mutex;
@@ -63,7 +62,7 @@ _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
 #else
   _S_single;
 #endif
-  
+
   // NB: As this is used in libsupc++, need to only depend on
   // exception. No stdexception classes, no use of std::string.
   class __concurrence_lock_error : public std::exception