[3/7] Fix load/store costs for strided groups

[Richard Sandiford]

vect_model_store_cost had:

  /* Costs of the stores.  */
  if (STMT_VINFO_STRIDED_P (stmt_info)
      && !STMT_VINFO_GROUPED_ACCESS (stmt_info))
    {
      /* N scalar stores plus extracting the elements.  */
      inside_cost += record_stmt_cost (body_cost_vec,
                                       ncopies * TYPE_VECTOR_SUBPARTS (vectype),
                                       scalar_store, stmt_info, 0, vect_body);

But non-SLP strided groups also use individual scalar stores rather than
vector stores, so I think we should skip this only for SLP groups.

The same applies to vect_model_load_cost.

Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?

Thanks,
Richard


gcc/
        * tree-vect-stmts.c (vect_model_store_cost): For non-SLP
        strided groups, use the cost of N scalar accesses instead
        of ncopies vector accesses.
        (vect_model_load_cost): Likewise.

diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index e90eeda..f883580 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -926,8 +926,7 @@ vect_model_store_cost (stmt_vec_info stmt_info, int ncopies,
 
   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
   /* Costs of the stores.  */
-  if (STMT_VINFO_STRIDED_P (stmt_info)
-      && !STMT_VINFO_GROUPED_ACCESS (stmt_info))
+  if (STMT_VINFO_STRIDED_P (stmt_info) && !(slp_node && grouped_access_p))
     {
       /* N scalar stores plus extracting the elements.  */
       inside_cost += record_stmt_cost (body_cost_vec,
@@ -1059,8 +1058,7 @@ vect_model_load_cost (stmt_vec_info stmt_info, int 
ncopies,
     }
 
   /* The loads themselves.  */
-  if (STMT_VINFO_STRIDED_P (stmt_info)
-      && !STMT_VINFO_GROUPED_ACCESS (stmt_info))
+  if (STMT_VINFO_STRIDED_P (stmt_info) && !(slp_node && grouped_access_p))
     {
       /* N scalar loads plus gathering them into a vector.  */
       tree vectype = STMT_VINFO_VECTYPE (stmt_info);