Re: [PATCH] Canonicalize &a to &a[0] during fold

[Richard Henderson <rth at redhat dot com>]

On Mon, Apr 25, 2005 at 11:06:44AM +0200, Richard Guenther wrote:
> I would have come up with followups that also replace
> (a + i) with &a[i].  Should this also be fixed in the frontends?

No, this is fine for fold.

The problem with &a vs &a[0] is one of type.  The front end is
broken wrt the type system.  Plugging that hole would allow a
groddy special case to be removed from check_pointer_types_r:

      if (!cpt_same_type (otype, dtype))
        {
          /* &array is allowed to produce a pointer to the element, rather than
             a pointer to the array type.  We must allow this in order to
             properly represent assigning the address of an array in C into
             pointer to the element type.  */
          gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
                      && POINTER_TYPE_P (ptype)
                      && cpt_same_type (TREE_TYPE (otype), dtype));
          break;
        }


r~