diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ab4ab36ea4c..f2b48289d6b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2016-11-25  Jakub Jelinek  <jakub@redhat.com>
+	    Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
+
+	PR middle-end/78501
+	* tree-vrp.c (extract_range_basic): Check for ptrdiff_type_node to be
+	non null and it's precision matches precision of lhs's type.
+
 2016-11-24  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/78476
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 33e0a755cfe..8bea4dbc3fb 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -4028,15 +4028,20 @@ extract_range_basic (value_range *vr, gimple *stmt)
 	  }
 	  return;
 	case CFN_BUILT_IN_STRLEN:
-	  {
-	    tree type = TREE_TYPE (gimple_call_lhs (stmt));
-	    tree max = vrp_val_max (ptrdiff_type_node);
-	    wide_int wmax = wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max)));
-	    tree range_min = build_zero_cst (type); 
-	    tree range_max = wide_int_to_tree (type, wmax - 1);
-	    set_value_range (vr, VR_RANGE, range_min, range_max, NULL);
-	  }
-	  return;
+	  if (tree lhs = gimple_call_lhs (stmt))
+	    if (ptrdiff_type_node
+		&& (TYPE_PRECISION (ptrdiff_type_node)
+		    == TYPE_PRECISION (TREE_TYPE (lhs))))
+	      {
+		tree type = TREE_TYPE (lhs);
+		tree max = vrp_val_max (ptrdiff_type_node);
+		wide_int wmax = wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max)));
+		tree range_min = build_zero_cst (type);
+		tree range_max = wide_int_to_tree (type, wmax - 1);
+		set_value_range (vr, VR_RANGE, range_min, range_max, NULL);
+		return;
+	      }
+	  break;
 	default:
 	  break;
 	}