[Bug tree-optimization/42652] vectorizer created unaligned vector insns

["irar at il dot ibm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #13 from irar at il dot ibm dot com  2010-01-18 12:17 -------
Does something like this make sense? (With this patch we will never use peeling
for function parameters, unless the builtin returns OK to peel for packed
types). 

Index: tree-vect-data-refs.c
===================================================================
--- tree-vect-data-refs.c       (revision 155880)
+++ tree-vect-data-refs.c       (working copy)
@@ -1010,10 +1010,29 @@ vector_alignment_reachable_p (struct dat
       tree type = (TREE_TYPE (DR_REF (dr)));
       tree ba = DR_BASE_OBJECT (dr);
       bool is_packed = false;
+      tree tmp = TREE_TYPE (DR_BASE_ADDRESS (dr));

       if (ba)
        is_packed = contains_packed_reference (ba);

+      is_packed = is_packed || contains_packed_reference (DR_BASE_ADDRESS
(dr));
+
+      if (!is_packed)
+        {
+          while (tmp)
+            {
+              is_packed = TYPE_PACKED (tmp);
+              if (is_packed)
+                break;
+
+              tmp = TREE_TYPE (tmp);
+            }
+        }
+
+      if (TREE_CODE (DR_BASE_ADDRESS (dr)) == SSA_NAME
+          && TREE_CODE (SSA_NAME_VAR (DR_BASE_ADDRESS (dr))) == PARM_DECL)
+        is_packed = true;
+
       if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "Unknown misalignment, is_packed = %d",is_packed);
       if (targetm.vectorize.vector_alignment_reachable (type, is_packed))


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42652