[PATCH] Add vector cost model density heuristic

[William J. Schmidt]

On Tue, 2012-06-19 at 14:48 +0200, Richard Guenther wrote:
> On Tue, 19 Jun 2012, William J. Schmidt wrote:
> 
> > I remember having this discussion, and I was looking for it to check on
> > the details, but I can't seem to find it either in my inbox or in the
> > archives.  Can you please point me to that again?  Sorry for the bother.
> 
> It was in the "Correct cost model for strided loads" thread.

Ah, right, thanks.  I think it will be best to make that a separate
patch in the series.  Like so:

(1) Add calls to the new interface without disturbing existing logic;
modify the profitability algorithms to query the new model for inside
costs.  Default algorithm for the model is to just sum costs as is done
today.
(1a) Split up the cost hooks (one for loads/stores with misalign parm,
one for vector_stmt with tree_code, etc.).
(x) Add heuristics to target models as desired.
(2) Handle the SLP ordering problem.
(3) Handle outside costs in the target model.
(4) Remove the now unnecessary cost fields and the calls that set them.

I'll start work on this series of patches as I have time between other
projects.

Thanks,
Bill

> 
> Richard.
>