[Bug tree-optimization/72443] VRP derives poor range for "y = (int)x + C;" when x has an anti-range

[Bug tree-optimization/72443] VRP derives poor range for "y = (int)x + C;" when x has an anti-range

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72443

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2016-07-26 00:00:00         |2021-7-20
           Severity|normal                      |enhancement
           Keywords|                            |missed-optimization

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #2)
> Sth that would greatly simplify VRP (IMHO) is to dump anti-ranges from the
> range representation and instead have the lattice value be composed of
> the union of two ranges (that's more powerful for ranges _and_ it can
> represent all anti-ranges) [just make it the union of N ranges with N
> being configurable - it might be possible to ditch equivalences on the
> way though they compose the range as intersections of N ranges]

I noticed the ranger work has that implemented.

[Bug tree-optimization/72443] VRP derives poor range for "y = (int)x + C;" when x has an anti-range

[amacleod at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72443

Andrew Macleod <amacleod at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amacleod at redhat dot com
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #4 from Andrew Macleod <amacleod at redhat dot com> ---
Ranger VRP passes produce:

Non-varying global ranges:
=========================:
y_7  : int [-2147483647, 5][12, +INF]


So.. fixed I guess.