[Bug tree-optimization/71818] [7 Regression] ICE in as_a, at is-a.h:192 w/ -O2 -ftree-vectorize

[alahay01 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71818

alahay01 at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

--- Comment #2 from alahay01 at gcc dot gnu.org ---
Fixed.

Allowing a non-invariant step to be incremented using vect_can_advance_ivs_p
was causing:
1) Incorrect vectorisation of the IV
and
2) Loop closed SSA to be broken (the step was being used outside the loop
directly instead of via a PHI).

The ICE was caused because vectorisable_live_operation was expecting the loop
to be in loop closed SSA.