Update on SVE/sizeless types for C and C++

[Jim Wilson]

On Tue, Nov 12, 2019 at 2:12 PM Richard Sandiford
<richard.sandiford@arm.com> wrote:
> Are both RVV intrinsic proposals like SVE in that all sizeless types
> can be/are built into the compiler?  If so, do you think the target hook
> added in:
>     https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00942.html
> would be enough for RVV too?  Or do the RVV proposals require support
> for user-defined sizeless types?

We only have built-in types.  I think we have 54 of them, 32 integer,
12 float, and 10 mask.  I hadn't thought about user-defined sizeless
types, and hope that I don't have to support that.

> If the hook is enough, I guess there are three ways we can go:
> (1) Add hooks for both targets, with similar functionality.  This means
>     a certain amount of cut-&-paste but also allows for more specific
>     error messages.

I think this would be OK.  I took a quick look at your patch.  I'm a
little surprised that you can't support alignof on a vector type, I
would think that depends on the base type for the vector, but maybe
this is a difference between SVE and RVV, or maybe I just haven't
gotten far enough to find the problem yet.  Otherwise it looks like
this would also work for the RVV support.

Jim