[PATCH] Clear DR_GROUP_NEXT_ELEMENT upon group dissolving

[Richard Biener]

I've tried to sanitize DR_GROUP_NEXT_ELEMENT accesses but there are too
many so the following instead makes sure DR_GROUP_NEXT_ELEMENT is never
non-NULL for !STMT_VINFO_GROUPED_ACCESS.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

        * tree-vect-data-refs.cc (vect_analyze_data_ref_access): When
        cancelling a DR group also clear DR_GROUP_NEXT_ELEMENT.
---
 gcc/tree-vect-data-refs.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc
index 920e3c120a6..202af7a8952 100644
--- a/gcc/tree-vect-data-refs.cc
+++ b/gcc/tree-vect-data-refs.cc
@@ -3206,6 +3206,7 @@ vect_analyze_data_ref_access (vec_info *vinfo, 
dr_vec_info *dr_info)
   if (loop_vinfo && integer_zerop (step))
     {
       DR_GROUP_FIRST_ELEMENT (stmt_info) = NULL;
+      DR_GROUP_NEXT_ELEMENT (stmt_info) = NULL;
       if (!nested_in_vect_loop_p (loop, stmt_info))
        return DR_IS_READ (dr);
       /* Allow references with zero step for outer loops marked
@@ -3225,6 +3226,7 @@ vect_analyze_data_ref_access (vec_info *vinfo, 
dr_vec_info *dr_info)
       /* Interleaved accesses are not yet supported within outer-loop
         vectorization for references in the inner-loop.  */
       DR_GROUP_FIRST_ELEMENT (stmt_info) = NULL;
+      DR_GROUP_NEXT_ELEMENT (stmt_info) = NULL;
 
       /* For the rest of the analysis we use the outer-loop step.  */
       step = STMT_VINFO_DR_STEP (stmt_info);
@@ -3247,6 +3249,7 @@ vect_analyze_data_ref_access (vec_info *vinfo, 
dr_vec_info *dr_info)
        {
          /* Mark that it is not interleaving.  */
          DR_GROUP_FIRST_ELEMENT (stmt_info) = NULL;
+         DR_GROUP_NEXT_ELEMENT (stmt_info) = NULL;
          return true;
        }
     }
-- 
2.43.0