Re: [PING] Fix PR46399 - missing mode promotion for libcall args

[Ian Lance Taylor <iant@google.com>]

"Andreas Krebbel" <krebbel@linux.vnet.ibm.com> writes:

> 2011-04-18  Andreas Krebbel  <Andreas.Krebbel@de.ibm.com>
>
> 	* calls.c (emit_library_call_value_1): Invoke
> 	promote_function_mode hook on libcall arguments.
> 	* explow.c (promote_function_mode, promote_mode): Handle TYPE
> 	argument being NULL.
> 	* targhooks.c (default_promote_function_mode): Lisewise.
> 	* config/s390/s390.c (s390_promote_function_mode): Likewise.
> 	* config/sparc/sparc.c (sparc_promote_function_mode): Likewise.
>
> 	* doc/tm.texi: Document that TYPE argument might be NULL.

>
>
> Index: gcc/calls.c
> ===================================================================
> *** gcc/calls.c.orig
> --- gcc/calls.c
> *************** emit_library_call_value_1 (int retval, r
> *** 3484,3489 ****
> --- 3484,3490 ----
>       {
>         rtx val = va_arg (p, rtx);
>         enum machine_mode mode = (enum machine_mode) va_arg (p, int);
> +       int unsigned_p = 0;
>   
>         /* We cannot convert the arg value to the mode the library wants here;
>   	 must do it earlier where we know the signedness of the arg.  */
> *************** emit_library_call_value_1 (int retval, r
> *** 3531,3539 ****
>   	  val = force_operand (XEXP (slot, 0), NULL_RTX);
>   	}
>   
> !       argvec[count].value = val;
>         argvec[count].mode = mode;
> ! 
>         argvec[count].reg = targetm.calls.function_arg (&args_so_far, mode,
>   						      NULL_TREE, true);
>   
> --- 3532,3540 ----
>   	  val = force_operand (XEXP (slot, 0), NULL_RTX);
>   	}
>   
> !       mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
>         argvec[count].mode = mode;
> !       argvec[count].value = convert_modes (mode, GET_MODE (val), val, 0);
>         argvec[count].reg = targetm.calls.function_arg (&args_so_far, mode,
>   						      NULL_TREE, true);


It seems to me that you should pass unsigned_p to convert_modes.


> Index: gcc/doc/tm.texi.in
> ===================================================================
> *** gcc/doc/tm.texi.in.orig
> --- gcc/doc/tm.texi.in
> *************** which an incoming parameter is copied, o
> *** 952,957 ****
> --- 952,959 ----
>   then the hook should return the same mode as @code{promote_mode}, though
>   the signedness may be different.
>   
> + @var{type} can be omitted when promoting function arguments of libcalls.
> + 
>   The default is to not promote arguments and return values.  You can
>   also define the hook to @code{default_promote_function_mode_always_promote}
>   if you would like to apply the same rules given by @code{PROMOTE_MODE}.

I think it would be clearer if you s/omitted/NULL/.

The patch is OK with those changes.

Thanks.

Ian