[Bug rtl-optimization/54342] [4.8 Regression] Wrong mode of call argument

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54342

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.0

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-08-21 11:08:27 UTC ---
> diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
> index 53554a9..bb39e7f 100644
> --- a/gcc/stor-layout.c
> +++ b/gcc/stor-layout.c
> @@ -1639,7 +1639,8 @@ compute_record_mode (tree type)
>    /* If we only have one real field; use its mode if that mode's size
>       matches the type's size.  This only applies to RECORD_TYPE.  This
>       does not apply to unions.  */
> -  if (TREE_CODE (type) == RECORD_TYPE && mode != VOIDmode
> +  if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE)
> +      && mode != VOIDmode
>        && host_integerp (TYPE_SIZE (type), 1)
>        && GET_MODE_BITSIZE (mode) == TREE_INT_CST_LOW (TYPE_SIZE (type)))
>      SET_TYPE_MODE (type, mode);

Reading the comment immediately makes the patch suspicious.