[Bug tree-optimization/62630] [5 regression] gcc.dg/graphite/vect-pr43423.c FAILs

["mircea.namolaru at inria dot fr" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62630

--- Comment #14 from Mircea Namolaru <mircea.namolaru at inria dot fr> ---
It seems to me that scalar evolution succeeds to determine
the number of iterations for the case of signed longs. Looking
in vectorization dump, first a symbolic expression for the number of 
iterations of a loop is found, and then vect_analyze_refs is entered.
The problem is that the code expect an offset of a load to be an induction
variable, 
but in our case an offset is only a cast of an induction variable, like
below:

 _56 = (intD.6) graphite_IV.5_53;
 _55 = aD.1830[_56];

The offset is found not to be an affine expression, and vectorization don't
succeed. But as the offset is a cast of an induction variable, it has the same
behaviour as an induction variable even if formally is not one. It seems to me
that somehow extending the code to support casts of induction variables
will solve our this problem.