Merging CCP and VRP?

[Kazu Hirata]

Hi Diego,

> There is a copy-propagation pass before VRP.  Or do you mean
> right before?  Sure, the ordering of these passes is in eternal
> flux anyway.

"Before", but doesn't have to be "right before".  The current ordering
is reasonable.

> > Currently, we still have these even after copy prop because we don't
> > allow copy propagation between const and non-const pointers, which I
> > think is a bit too restrictive.
> > 
> I assume these are blocked by may_propagate_copy.  What's
> blocking these?  Do they have different alias set numbers or do
> we need a conversion from the const to the non-const version?

Yes, they are blocked by may_propagate_copy.  Seems to be const
v.s. non-const pointer issue.  I haven't come up with a brakedown of
reasons why copies are blocked.

Kazu Hirata