[Bug tree-optimization/92932] New: Optimizers generate wrong code due to aggressive data optimization.

[gjl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92932

            Bug ID: 92932
           Summary: Optimizers generate wrong code due to aggressive data
                    optimization.
           Product: gcc
           Version: 8.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gjl at gcc dot gnu.org
  Target Milestone: ---

GCC sometimes aliases symbols if they refer to identical data.  However, in
order for this to be legitimate optimization, it must be ensured that the code
will be accessed in the same way.

This is not always the case, an example where this generates wrong code is
PR92606.

Such a new hook needs at least the following information to disallow aliasing 
by means of .set or similar means:

* The attributes specified for either objects.

* The address spaces specified for either objects.