Re: [PATCH] Teach the vectorizer about multiple sizes

[Richard Henderson <rth at redhat dot com>]

On 10/06/2010 01:54 PM, Richard Guenther wrote:
> I think we also want to consider larger sizes if the target prefers
> the smaller one but only the larger one can actually vectorize things.

I'm going to go out on a limb and suggest that the target will 
always prefer the largest available mode.  Certainly that's 
the case with all of the prefered_vector_mode hooks that you
wrote in the other patch.

If we wind up with a current_vector_size < max_vector_size,
it'll be because we vectorized a type that we don't support
at max_vector_size.  Therefore if we try again with a larger
vector size we'll simply fail again.

> But we can certainly start with your suggestion (I can check if we
> miss anything in SPEC 2006 when restricting the 2nd loop to smaller
> sizes).

Sure.


r~