Re: record_ranges_from_incoming_edge: use value_range API for creating new range

[Aldy Hernandez <aldyh at redhat dot com>]

On 11/8/18 9:24 AM, Richard Biener wrote:
> On Thu, Nov 8, 2018 at 1:17 PM Aldy Hernandez <aldyh@redhat.com> wrote:
> > This one's rather obvious and does not depend on any get_range_info API
> > change.
> >
> > OK for trunk?
>
> Hmm, no - that's broken.  IIRC m_equiv are shared bitmaps if you
> do tem = *old_vr so you modify it in place with equiv_clear().

Good point.

> Thus, operator= should be really deleted or mapped to value_range::set()
> in which case tem = *old_vr would do useless bitmap allocation and
> copying that you then clear.

Actually, I was thinking that perhaps the assignment and equality 
operators should disregard the equivalence bitmap.  In this case, copy 
everything EXCEPT the bitmap and set the resulting equivalence bitmap to 
NULL.

It's also annoying to use ::ignore_equivs_equal_p().  Since that seems 
to be the predominant way of comparing ranges, perhaps it should be the 
default.

Aldy