[Bug tree-optimization/71683] New: [7 Regression] ICE in gen_phi_arg_condition, at tree-if-conv.c:1705 w/ -ftree-vectorize -O2 (and above)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71683

            Bug ID: 71683
           Summary: [7 Regression] ICE in gen_phi_arg_condition, at
                    tree-if-conv.c:1705 w/ -ftree-vectorize -O2 (and
                    above)
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc-7.0.0-alpha20160626 ICEs when compiling the following reduced testcase w/
-ftree-vectorize -O2 (-O3, -Ofast):

short unsigned int ve;

void
u1 (void)
{
  int oq = 0;

  while (ve != 0)
    {
      int j4, w7 = oq;

      oq = 0 / oq;
      ve %= oq;
      j4 = ve ^ 1;
      ve ^= oq;
      if (j4 != 0 ? j4 : ve)
        oq = ve;
      else
        if (w7 != 0)
          oq = ve;
    }
}

% gcc-7.0.0-alpha20160626 -c -O2 -ftree-vectorize h0j2boji.c
h0j2boji.c: In function 'u1':
h0j2boji.c:4:1: internal compiler error: in gen_phi_arg_condition, at
tree-if-conv.c:1705