conversions between vectors

[Aldy Hernandez]

> Does Dan's patch include docs?  Let's first get in docs for vectors
> corresponding to valarrays (effectively explaining those parts of
> valarrays for C programmers), stating what is and is not currently

ok, i don't understand c++ (or valarrays) sufficiently to be able to
write those docs.  for that matter, i don't agree we should be
patterning vectors after valarrays just because it's a well known
interface.  but if this is the route agreed by everyone, then i suggest
someone knowledgeable with valarrays document the corresponding C
extensions.

would you be willing to write the docs?

i volunteer to work on the operators on vectors, if someone can help out
on the docs-- at least a basic documentary infrastructure we can base
off of.

> supported, then start adding the semantics (updating the docs as each part
> is implemented).  But unless you can produce a bug that this fixes, this
> ought to be 3.2 (or some new branch) material rather than for the mainline
> now.

agreed.

this is something i want to do for 3.2.  for that matter i want to
implement the whole shebang of sythesizeable vector operations.  if you
define vector size to be 16, and you only have vectors of 8bytes, then
the optab code should be able to use a pair of V2SIs to do V4SI
operations.  this should provide a basis for auto-vectorization work.

-- 
Aldy Hernandez			E-mail: aldyh@redhat.com
Professional Gypsy
Red Hat, Inc.