On Thu, Aug 03, 2017 at 10:01:41AM -0500, Segher Boessenkool wrote:
> Hi Mike,
>
> On Wed, Aug 02, 2017 at 10:28:55AM -0400, Michael Meissner wrote:
> > On Fri, Jul 28, 2017 at 04:08:50PM -0500, Segher Boessenkool wrote:
> > > I think calling this with the rtx elementN args makes this only more
> > > complicated (the function comment doesn't say what they are or what
> > > NULL means, btw).
>
> You didn't handle the first part of this as far as I see? It's the
> big complicating issue here.
I am not sure exactly what you are asking for. This is like the other output
functions that take the rtx insns.
> > + If ELEMENT1 is null, use the top 64-bit double word of ARG1. If it is
> > + non-NULL, it is a 0 or 1 constant that gives the vector element number
> > to
> > + use for extracting the 64-bit double word from ARG1.
> > +
> > + If ELEMENT2 is null, use the top 64-bit double word of ARG2. If it is
> > + non-NULL, it is a 0 or 1 constant that gives the vector element number
> > to
> > + use for extracting the 64-bit double word from ARG2.
> > +
> > + The element number is based on the user element ordering, set by the
> > + endianess and by the -maltivec={le,be} options. */
>
> ("endianness", two n's).
>
> I don't like using NULL as a magic value at all; it does not simplify
> this interface, it complicates it instead.
>
> Can you move the "which half is high" decision to the callers?
And then essentially there is no need for the function, since each of the 4
concat variants have to have the logic to support big endian, -maltivec=be, and
-maltivec=le.
Let me see what I can do about it.
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: [email protected], phone: +1 (978) 899-4797
