Re: VAX Ultrix bootstrap with gcc-2.96 20000519: genrecog failure

["John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>]

The patch fixed the missing return value in my test program.  Hopefully,
it will allow the build to complete.

Thanks,
Dave

> 
> On Sat, May 27, 2000 at 05:38:48PM -0400, John David Anglin wrote:
> > In looking at function.c (expand_function_end), I can't see how struct
> > returns every worked in this situation:
> 
> The code in this area has changed quite a bit over the past year.
> It's possible that it didn't work before the changes, or that it
> worked by accident, or that I really did mess up.
> 
> > The movq is generated by line 6673 of function.c.   However, doesn't
> > something need to be done to get it into current_function_return_rtx?
> 
> I don't think it's supposed to.  Looking at where that value gets
> loaded up, it appears that diddle_return_value isn't handling this
> case correctly.
> 
> I've given i386 and sparc64 output (to pick two other styles of struct
> return at random) a quick glance, and nothing appears to be broken by
> this change; I'll wait for a complete bootstrap and test cycle to be sure.
> 
> 
> r~
> 
> 
> 	* function.c (diddle_return_value): A pcc-style struct return
> 	returns a pointer.
> 
> Index: function.c
> ===================================================================
> RCS file: /cvs/gcc/egcs/gcc/function.c,v
> retrieving revision 1.199
> diff -c -p -d -r1.199 function.c
> *** function.c	2000/05/27 20:10:38	1.199
> --- function.c	2000/05/28 02:50:35
> *************** diddle_return_value (doit, arg)
> *** 6319,6332 ****
>        void *arg;
>   {
>     rtx outgoing = current_function_return_rtx;
>   
>     if (! outgoing)
>       return;
>   
> !   if (GET_CODE (outgoing) == REG
> !       && REGNO (outgoing) >= FIRST_PSEUDO_REGISTER)
>       {
>         tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
>   #ifdef FUNCTION_OUTGOING_VALUE
>         outgoing = FUNCTION_OUTGOING_VALUE (type, current_function_decl);
>   #else
> --- 6319,6343 ----
>        void *arg;
>   {
>     rtx outgoing = current_function_return_rtx;
> +   int pcc;
>   
>     if (! outgoing)
>       return;
>   
> !   pcc = (current_function_returns_struct
> !          || current_function_returns_pcc_struct);
> ! 
> !   if ((GET_CODE (outgoing) == REG
> !        && REGNO (outgoing) >= FIRST_PSEUDO_REGISTER)
> !       || pcc)
>       {
>         tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
> + 
> +       /* A PCC-style return returns a pointer to the memory in which
> + 	 the structure is stored.  */
> +       if (pcc)
> + 	type = build_pointer_type (type);
> + 
>   #ifdef FUNCTION_OUTGOING_VALUE
>         outgoing = FUNCTION_OUTGOING_VALUE (type, current_function_decl);
>   #else
> 


-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)