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

[Corinna Vinschen <vinschen at redhat dot com>]

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.