[Bug c/70812] New: Delay folding in C front-end

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70812

            Bug ID: 70812
           Summary: Delay folding in C front-end
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: glisse at gcc dot gnu.org
  Target Milestone: ---

Hello,

gcc.dg/gomp/loop-1.c recently gained a few xfails
https://gcc.gnu.org/ml/gcc-patches/2016-04/msg01417.html

Those happen because the C front-end folds i+=i to i*=2 before the OMP code has
a chance to check if the increment has a supported form. I think the problem
only happens for forms which are invalid anyway.

If you believe the behavior is fine, then we could update the testcase so the
xfails become passes.