re PR libgomp/59194 (tsan detects race for real variables in an OMP reduction clause)

	PR libgomp/59194
	* omp-low.c (expand_omp_atomic_pipeline): Expand the initial
	load as __atomic_load_N if possible.

From-SVN: r206572

gcc/ChangeLog

+2014-01-13  Jakub Jelinek  <jakub@redhat.com>
+
+	PR libgomp/59194
+	* omp-low.c (expand_omp_atomic_pipeline): Expand the initial
+	load as __atomic_load_N if possible.
+
 2014-01-11  David Edelsohn  <dje.gcc@gmail.com>
 
 	* config/rs6000/rs6000.c (rs6000_expand_mtfsf_builtin): Remove

gcc/omp-low.c

@@ -7536,12 +7536,21 @@ expand_omp_atomic_pipeline (basic_block load_bb, basic_block store_bb,
       loadedi = loaded_val;
     }
 
+  fncode = (enum built_in_function) (BUILT_IN_ATOMIC_LOAD_N + index + 1);
+  tree loaddecl = builtin_decl_explicit (fncode);
+  if (loaddecl)
+    initial
+      = fold_convert (TREE_TYPE (TREE_TYPE (iaddr)),
+		      build_call_expr (loaddecl, 2, iaddr,
+				       build_int_cst (NULL_TREE,
+						      MEMMODEL_RELAXED)));
+  else
+    initial = build2 (MEM_REF, TREE_TYPE (TREE_TYPE (iaddr)), iaddr,
+		      build_int_cst (TREE_TYPE (iaddr), 0));
+
   initial
-    = force_gimple_operand_gsi (&si,
-				build2 (MEM_REF, TREE_TYPE (TREE_TYPE (iaddr)),
-					iaddr,
-					build_int_cst (TREE_TYPE (iaddr), 0)),
-				true, NULL_TREE, true, GSI_SAME_STMT);
+    = force_gimple_operand_gsi (&si, initial, true, NULL_TREE, true,
+				GSI_SAME_STMT);
 
   /* Move the value to the LOADEDI temporary.  */
   if (gimple_in_ssa_p (cfun))