Re: [PATCH] rs6000: Skip overload instances with uninitialized fntype (PR103622)

[Bill Schmidt <wschmidt@linux.ibm.com>]

Hi!  I'd like to ping this patch, now that I'm back from break.

Thanks!
Bill

On 12/13/21 10:15 AM, Bill Schmidt wrote:
> Hi!
>
> For some data types like IEEE-128, we determine whether the type is available
> at built-in function initialization time.  If it's not, then we don't provide
> the function type for function instances that require the data type.  PR103622
> observes that this can cause us to ICE when running the list of instances when
> the target doesn't support the data type.
>
> Ideally, we wouldn't even put such an instance in the list of instances that
> an overload can map to, but to do that is much more complicated.  Instead,
> this patch just ensures we don't dereference a NULL pointer when the situation
> arises.
>
> Tested the fix on a powerpc-e300c3-linux-gnu cross.  Bootstrapped and tested on
> powerpc64le-linux-gnu with no regressions.  Is this okay for trunk?
>
> Thanks!
> Bill
>
>
> 2021-12-13  Bill Schmidt  <wschmidt@linux.ibm.com>
>
> gcc/
> 	PR target/103622
> 	* config/rs6000/rs6000-c.c (altivec_resolve_new_overloaded_builtin):
> 	Skip over instances with undefined function types.
> ---
>  gcc/config/rs6000/rs6000-c.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/gcc/config/rs6000/rs6000-c.c b/gcc/config/rs6000/rs6000-c.c
> index 8e83d97e72f..fc4cc929884 100644
> --- a/gcc/config/rs6000/rs6000-c.c
> +++ b/gcc/config/rs6000/rs6000-c.c
> @@ -2943,6 +2943,12 @@ altivec_resolve_new_overloaded_builtin (location_t loc, tree fndecl,
>  
>  	for (; instance != NULL; instance = instance->next)
>  	  {
> +	    /* It is possible for an instance to require a data type that isn't
> +	       defined on this target, in which case instance->fntype will be
> +	       NULL.  */
> +	    if (!instance->fntype)
> +	      continue;
> +
>  	    bool mismatch = false;
>  	    tree nextparm = TYPE_ARG_TYPES (instance->fntype);
>