[PATCH] Make SRA produce integer replacements for enumeration types

[Martin Jambor]

Hi,

the patch below makes SRA produce intere type replacements when it
currently produces enumeration type ones because this then may cause
VRP to assume wrong bounds (PR 49911).

I do not know how to create a testcase for the PR this should solve
because I could not reproduce it on yesterday's trunk checkout.

The patch is against trunk, where it successfully passes bootstrap and
testing on x86_64-linux, but applies well also to 4.6 and 4.5 branches
and there has been a request to commit them there as well so I'd like
to do so (after testing it on them which I have not done yet).

OK?

Thanks,

Martin


2011-09-05  Martin Jambor  <mjam...@suse.cz>

        PR tree-optimization/49911
        * tree-sra.c (analyze_access_subtree): Change type of to-be-replaced
        enumerations to the corresponding plain integer type.

Index: src/gcc/tree-sra.c
===================================================================
--- src.orig/gcc/tree-sra.c
+++ src/gcc/tree-sra.c
@@ -2075,13 +2075,25 @@ analyze_access_subtree (struct access *r
          || ((root->grp_scalar_read || root->grp_assignment_read)
              && (root->grp_scalar_write || root->grp_assignment_write))))
     {
+      bool new_integer_type;
+      if (TREE_CODE (root->type) == ENUMERAL_TYPE)
+       {
+         tree rt = root->type;
+         root->type = build_nonstandard_integer_type (TYPE_PRECISION (rt),
+                                                      TYPE_UNSIGNED (rt));
+         new_integer_type = true;
+       }
+      else
+       new_integer_type = false;
+
       if (dump_file && (dump_flags & TDF_DETAILS))
        {
          fprintf (dump_file, "Marking ");
          print_generic_expr (dump_file, root->base, 0);
-         fprintf (dump_file, " offset: %u, size: %u: ",
+         fprintf (dump_file, " offset: %u, size: %u ",
                   (unsigned) root->offset, (unsigned) root->size);
-         fprintf (dump_file, " to be replaced.\n");
+         fprintf (dump_file, " to be replaced%s.\n",
+                  new_integer_type ? " with an integer": "");
        }
 
       root->grp_to_be_replaced = 1;