re PR tree-optimization/39331 (OpenMP and return-slot-optimization generate invalid gimple)

2009-03-01  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/39331
	* omp-low.c (lower_send_shared_vars): Do not receive new
	values for the reference of DECL_BY_REFERENCE parms or results.

From-SVN: r144531

gcc/ChangeLog

+2009-03-01  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/39331
+	* omp-low.c (lower_send_shared_vars): Do not receive new
+	values for the reference of DECL_BY_REFERENCE parms or results.
+
 2009-03-01  Jan Hubicka  <jh@suse.cz>
 
 	PR debug/39267

gcc/omp-low.c

@@ -2821,7 +2821,14 @@ lower_send_shared_vars (gimple_seq *ilist, gimple_seq *olist, omp_context *ctx)
 	  x = build_sender_ref (ovar, ctx);
 	  gimplify_assign (x, var, ilist);
 
-	  if (!TREE_READONLY (var))
+	  if (!TREE_READONLY (var)
+	      /* We don't need to receive a new reference to a result
+	         or parm decl.  In fact we may not store to it as we will
+		 invalidate any pending RSO and generate wrong gimple
+		 during inlining.  */
+	      && !((TREE_CODE (var) == RESULT_DECL
+		    || TREE_CODE (var) == PARM_DECL)
+		   && DECL_BY_REFERENCE (var)))
 	    {
 	      x = build_sender_ref (ovar, ctx);
 	      gimplify_assign (var, x, olist);