re PR tree-optimization/72517 (436.cactusADM: More than 40% regression in O3 and...

2016-07-27  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/72517
	* tree-vect-data-refs.c (vect_analyze_data_ref_dependences):
	Revert change to not compute read-read dependences.

From-SVN: r238783

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e5aa7c76f8a95088cd58203101dd0e3278c0ee62..d2a295352ffd73cc6f963273a6657e561f9899ca 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-07-27  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/72517
+       * tree-vect-data-refs.c (vect_analyze_data_ref_dependences):
+       Revert change to not compute read-read dependences.
+
 2016-07-27  Richard Biener  <rguenther@suse.de>
 
        * predict.c (set_even_probabilities): Make nedges unsigned.

diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index 9a5408e14a52a2da4795a85cd0fe5dae3775aaf5..e908c865fbd79a3fb5f24d7a861732dfdd4acf55 100644 (file)
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -473,9 +473,10 @@ vect_analyze_data_ref_dependences (loop_vec_info loop_vinfo, int *max_vf)
     .create (LOOP_VINFO_DATAREFS (loop_vinfo).length ()
             * LOOP_VINFO_DATAREFS (loop_vinfo).length ());
   LOOP_VINFO_NO_DATA_DEPENDENCIES (loop_vinfo) = true;
+  /* We need read-read dependences to compute STMT_VINFO_SAME_ALIGN_REFS.  */
   if (!compute_all_dependences (LOOP_VINFO_DATAREFS (loop_vinfo),
                                &LOOP_VINFO_DDRS (loop_vinfo),
-                               LOOP_VINFO_LOOP_NEST (loop_vinfo), false))
+                               LOOP_VINFO_LOOP_NEST (loop_vinfo), true))
     return false;
 
   FOR_EACH_VEC_ELT (LOOP_VINFO_DDRS (loop_vinfo), i, ddr)