re PR tree-optimization/69719 (wrong code at -O3 on x86_64-linux-gnu)

2016-02-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/69719
	* tree-vect-data-refs.c (vect_prune_runtime_alias_test_list):
	Adjust previous fix by ensuring that dr_a1 is left of dr_a2.

From-SVN: r233262

gcc/ChangeLog

+2016-02-10  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/69719
+	* tree-vect-data-refs.c (vect_prune_runtime_alias_test_list):
+	Adjust previous fix by ensuring that dr_a1 is left of dr_a2.
+
 2016-02-09  Andrew Pinski  <apinski@cavium.com>
 
 	PR tree-opt/69282

gcc/tree-vect-data-refs.c

@@ -3081,9 +3081,12 @@ vect_prune_runtime_alias_test_list (loop_vec_info loop_vinfo)
 	      || !tree_fits_shwi_p (dr_a2->offset))
 	    continue;
 
+	  /* Make sure dr_a1 starts left of dr_a2.  */
+	  if (tree_int_cst_lt (dr_a2->offset, dr_a1->offset))
+	    std::swap (*dr_a1, *dr_a2);
+
 	  unsigned HOST_WIDE_INT diff
-	    = absu_hwi (tree_to_shwi (dr_a2->offset)
-			- tree_to_shwi (dr_a1->offset));
+	    = tree_to_shwi (dr_a2->offset) - tree_to_shwi (dr_a1->offset);
 
 
 	  /* Now we check if the following condition is satisfied: