Re: [RFA] sh-tdep.c (sh_use_struct_convention): Restructure and fix

Corinna Vinschen
2003-10-10T16:59:07Z

On Fri, Oct 10, 2003 at 12:43:27PM -0400, Elena Zannoni wrote:
> Corinna Vinschen writes:
> > static int
> > sh_use_struct_convention (int gcc_p, struct type *type)
> > {
> > int len = TYPE_LENGTH (type);
> > int nelem = TYPE_NFIELDS (type);
> >
> > /* Non-power of 2 length types and types bigger than 8 bytes (which don't
> > fit in two registers anyway) use struct convention. */
> > if (len != 1 && len != 2 && len != 4 && len != 8)
> > return 1;
> >
> > /* Scalar types and aggregate types with exactly one field are aligned
> > by definition. They are returned in registers. */
> > if (nelem <= 1)
> > return 0;
> >
> > /* If the first field in the aggregate has the same length as the entire
> > aggregate type, the type is returned in registers. */
> > if (TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0)) == len)
> > return 0;
> >
> > /* If the size of the aggregate is 8 bytes and the first field is
> > of size 4 bytes its alignment is equal to long long's alignment,
> > so it's returned in registers. */
> > if (len == 8 && TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0)) == 4)
> > return 0;
> >
> > /* Otherwise use struct convention. */
> > return 1;
> > }
>
> Much better, however, I would still like to know what the behavior is
> for a struct of 2 chars. Probably this needs another test case.

A struct of two chars is returned in memory. That's correct.

Corinna

--
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.