Add a combined_fn enum

[Bernd Schmidt]

On 11/09/2015 03:57 PM, Richard Sandiford wrote:

> I'm not sure what you mean by "fix" though.  I don't think we can change
> any of the constraints above.

I don't see why they couldn't be relaxed. What's stopping us from 
defining some builtins independently of the frontends, and don't all 
languages except Fortran use the normal builtins.def anyway? Also - if 
you can have an internal function without a fndecl, why wouldn't it work 
to allow that for builtins as well? But this is probably moot since I 
can now see a little more clearly what you want to do.

> The main goal is to allow functions to be vectorised simply by defining
> the associated optab.

Ok. So these internal functions would support arbitrary modes like 
V[1248][SDX]F etc., unlike the builtins? That wasn't entirely clear from 
the patches I looked at, it seemed like you were just duplicating every 
builtin as an internal function (something to which I would have objected).


Bernd