PR middle-end/51038

	libstdc++-v3
	* include/bits/atomic_base.h (atomic_thread_fence): Call built-in.
	(atomic_signal_fence): Call built-in.
	(test_and_set, clear): Call new atomic built-ins.

	gcc
	* builtins.c (expand_builtin_atomic_clear): New.  Expand atomic_clear.
	(expand_builtin_atomic_test_and_set): New.  Expand atomic test_and_set.
	(expand_builtin): Add cases for test_and_set and clear.
	* sync-builtins.def (BUILT_IN_ATOMIC_TEST_AND_SET): New.
	(BUILT_IN_ATOMIC_CLEAR): New.

	testsuite
	* gcc.dg/atomic-invalid.c: Add test for invalid __atomic_clear models.
	* gcc.dg/atomic-flag.c: New.  Test __atomic_test_and_set and
	__atomic_clear.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181271 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 21 insertions, 50 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index c25dd282d05..826ca4482dc 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,10 @@
+2011-11-10  Andrew MacLeod  <amacleod@redhat.com>
+
+	PR middle-end/51038
+	* include/bits/atomic_base.h (atomic_thread_fence): Call built-in.
+	(atomic_signal_fence): Call built-in.
+	(test_and_set, clear): Call new atomic built-ins.
+
 2011-11-09  Jonathan Wakely  <jwakely.gcc@gmail.com>
 
 	* include/bits/allocator.h (__shrink_to_fit_aux::_S_do_it): Create
diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h
index 5327c1bfa21..f0336611d3f 100644
--- a/libstdc++-v3/include/bits/atomic_base.h
+++ b/libstdc++-v3/include/bits/atomic_base.h
@@ -68,11 +68,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     return __mo2;
   }
 
-  void
-  atomic_thread_fence(memory_order __m) noexcept;
+  inline void
+  atomic_thread_fence(memory_order __m) noexcept
+  {
+    __atomic_thread_fence (__m);
+  }
 
-  void
-  atomic_signal_fence(memory_order __m) noexcept;
+  inline void
+  atomic_signal_fence(memory_order __m) noexcept
+  {
+    __atomic_thread_fence (__m);
+  }
 
   /// kill_dependency
   template<typename _Tp>
@@ -261,35 +267,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     bool
     test_and_set(memory_order __m = memory_order_seq_cst) noexcept
     {
-      /* The standard *requires* this to be lock free.  If exchange is not
-	 always lock free, the resort to the old test_and_set.  */
-      if (__atomic_always_lock_free (sizeof (_M_i), 0))
-	return __atomic_exchange_n(&_M_i, 1, __m);
-      else
-        {
-	  /* Sync test and set is only guaranteed to be acquire.  */
-	  if (__m == memory_order_seq_cst || __m == memory_order_release
-	      || __m == memory_order_acq_rel)
-	    atomic_thread_fence (__m);
-	  return __sync_lock_test_and_set (&_M_i, 1);
-	}
+      return __atomic_test_and_set (&_M_i, __m);
     }
 
     bool
     test_and_set(memory_order __m = memory_order_seq_cst) volatile noexcept
     {
-      /* The standard *requires* this to be lock free.  If exchange is not
-	 always lock free, the resort to the old test_and_set.  */
-      if (__atomic_always_lock_free (sizeof (_M_i), 0))
-	return __atomic_exchange_n(&_M_i, 1, __m);
-      else
-        {
-	  /* Sync test and set is only guaranteed to be acquire.  */
-	  if (__m == memory_order_seq_cst || __m == memory_order_release
-	      || __m == memory_order_acq_rel)
-	    atomic_thread_fence (__m);
-	  return __sync_lock_test_and_set (&_M_i, 1);
-	}
+      return __atomic_test_and_set (&_M_i, __m);
     }
 
     void
@@ -299,17 +283,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __glibcxx_assert(__m != memory_order_acquire);
       __glibcxx_assert(__m != memory_order_acq_rel);
 
-      /* The standard *requires* this to be lock free.  If store is not always
-	 lock free, the resort to the old style __sync_lock_release.  */
-      if (__atomic_always_lock_free (sizeof (_M_i), 0))
-	__atomic_store_n(&_M_i, 0, __m);
-      else
-        {
-	  __sync_lock_release (&_M_i, 0);
-	  /* __sync_lock_release is only guaranteed to be a release barrier.  */
-	  if (__m == memory_order_seq_cst)
-	    atomic_thread_fence (__m);
-	}
+      __atomic_clear (&_M_i, __m);
     }
 
     void
@@ -319,17 +293,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __glibcxx_assert(__m != memory_order_acquire);
       __glibcxx_assert(__m != memory_order_acq_rel);
 
-      /* The standard *requires* this to be lock free.  If store is not always
-	 lock free, the resort to the old style __sync_lock_release.  */
-      if (__atomic_always_lock_free (sizeof (_M_i), 0))
-	__atomic_store_n(&_M_i, 0, __m);
-      else
-        {
-	  __sync_lock_release (&_M_i, 0);
-	  /* __sync_lock_release is only guaranteed to be a release barrier.  */
-	  if (__m == memory_order_seq_cst)
-	    atomic_thread_fence (__m);
-	}
+      __atomic_clear (&_M_i, __m);
     }
   };