more m32c brokenness

[Richard Guenther]

On Wed, Apr 9, 2008 at 10:40 PM, DJ Delorie <dj@redhat.com> wrote:
>
>  I tracked it down to this:
>
>
>         /* Allow conversions between integral types and pointers only if
>            there is no sign or zero extension involved.  */
>         if (((POINTER_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op)))
>              || (POINTER_TYPE_P (TREE_TYPE (op)) && INTEGRAL_TYPE_P (type)))
>             && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op)))
>           return false;
>
>  The code does not do what the comment says.  It also requires that
>  there be no truncation.
>
>  However, of course, other parts of the compiler complain about
>  truncation as well.
>
>  The root cause is this:
>
>       ptr = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (ptr), ptr,
>                          fold_convert (sizetype, vtable));
>
>  We fold_convert to sizetype, without regard for whether it's the same
>  precision as TREE_TYPE (ptr).  vtable is the right size, ptr is the
>  right size, but we're creating an intermediate that's the wrong size.
>
>  Can we put in a calculate-unsigned-for-type call here?  That should be
>  sizetype for everyone else, but the special type for m32c.

This particular case indeed needs fixing (I assume vtable is a pointer).
There is build_nonstandard_integer_type for this.

Richard.