[Bug tree-optimization/49444] IV-OPTs changes an unaligned loads into aligned loads incorrectly

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49444

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-12-16 
00:33:10 UTC ---
This is the patch which I ended up with:
Index: tree-ssa-loop-ivopts.c
===================================================================
--- tree-ssa-loop-ivopts.c    (revision 61449)
+++ tree-ssa-loop-ivopts.c    (revision 61858)
@@ -6066,6 +6066,7 @@ rewrite_use_address (struct ivopts_data
   tree base_hint = NULL_TREE;
   tree ref, iv;
   bool ok;
+  tree type;

   adjust_iv_update_pos (cand, use);
   ok = get_computation_aff (data->current_loop, use, cand, use->stmt, &aff);
@@ -6087,7 +6088,13 @@ rewrite_use_address (struct ivopts_data
     base_hint = var_at_stmt (data->current_loop, cand, use->stmt);

   iv = var_at_stmt (data->current_loop, cand, use->stmt);
-  ref = create_mem_ref (&bsi, TREE_TYPE (*use->op_p), &aff,
+  type = TREE_TYPE (*use->op_p);
+  if (TREE_CODE (*use->op_p) == COMPONENT_REF)
+    {
+      unsigned align = DECL_ALIGN (TREE_OPERAND (*use->op_p, 1));
+      type = build_aligned_type (type, align);
+    }
+  ref = create_mem_ref (&bsi, type, &aff,
             reference_alias_ptr_type (*use->op_p),
             iv, base_hint, data->speed);
   copy_ref_info (ref, *use->op_p);
--- CUT ---
I also implemented on mips the misalignedmove patterns too.