check for unstructured control flow

	* graphite-scop-detection.c (scop_detection::harmful_loop_in_region):
	Discard unstructured if-then-else regions.

Co-Authored-By: Sebastian Pop <s.pop@samsung.com>

From-SVN: r232657

gcc/ChangeLog

 2016-01-21  Aditya Kumar  <aditya.k7@samsung.com>
 	    Sebastian Pop  <s.pop@samsung.com>
 
+	* graphite-scop-detection.c (scop_detection::harmful_loop_in_region):
+	Discard unstructured if-then-else regions.
+
+2016-01-21  Aditya Kumar  <aditya.k7@samsung.com>
+	    Sebastian Pop  <s.pop@samsung.com>
+
         * graphite-sese-to-poly.c (set_scop_parameter_dim): Remove.
         (cleanup_loop_iter_dom): Remove.
         (build_loop_iteration_domains): Remove.

gcc/graphite-scop-detection.c

@@ -1078,6 +1078,18 @@ scop_detection::harmful_loop_in_region (sese_l scop) const
 	  return true;
 	}
 
+      /* Check for unstructured control flow: CFG not generated by structured
+	 if-then-else.  */
+      if (bb->succs->length () > 1)
+	{
+	  edge e;
+	  edge_iterator ei;
+	  FOR_EACH_EDGE (e, ei, bb->succs)
+	    if (!dominated_by_p (CDI_POST_DOMINATORS, bb, e->dest)
+		&& !dominated_by_p (CDI_DOMINATORS, e->dest, bb))
+	      return true;
+	}
+
       /* Collect all loops in the current region.  */
       loop_p loop = bb->loop_father;
       if (loop_in_sese_p (loop, scop))