[Bug tree-optimization/83544] Missed optimization opportunity for constant folding

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83544

Andrew Pinski  changed:

   What|Removed |Added

 Status|NEW |RESOLVED
   Target Milestone|--- |11.0
 Resolution|--- |FIXED

--- Comment #2 from Andrew Pinski  ---
Fixed 100% in 11+ by r11-6100, there was some other VRP patch back in GCC 9
which also fixed this too but I can't find it.

[Bug tree-optimization/83544] Missed optimization opportunity for constant folding

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83544

Andrew Pinski  changed:

   What|Removed |Added

   Severity|normal  |enhancement
  Known to fail||8.5.0
  Known to work||9.1.0, 9.4.0

[Bug tree-optimization/83544] Missed optimization opportunity for constant folding

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83544

Richard Biener  changed:

   What|Removed |Added

   Keywords||missed-optimization
 Status|UNCONFIRMED |NEW
   Last reconfirmed||2018-01-02
 Ever confirmed|0   |1

[Bug tree-optimization/83544] Missed optimization opportunity for constant folding

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83544

--- Comment #1 from Marc Glisse  ---
In one case we optimize super early to
  int t = 1 / (int) x <= 0 ? 1 / 0 : 1;
which prevents the VRP optimization from the other case. We almost recover in
isolate-paths, except that Jeff insisted on using __builtin_trap() instead of
__builtin_unreachable(), so we don't. We could still simplify
  _2 = 1 / x.1_1;
  if (_2 != 1)
a bit to avoid actually performing the division, I think that's already tracked
in one of your earlier PRs.