[Bug tree-optimization/79405] New: [7 Regression] Compile-time hog w/ -O2 (-Os, -O3) on 32-bit BE powerpc targets

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79405

            Bug ID: 79405
           Summary: [7 Regression] Compile-time hog w/ -O2 (-Os, -O3) on
                    32-bit BE powerpc targets
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: powerpc-*-linux-gnu*

gcc-7.0.0-alpha20170205 snapshot takes large (or indefinite?) time to compile
the following snippet at -O2 (-Os, -O3) for 32-bit BE powerpc:

char cz;
long long int xx, u2;

void
qv (int js, int wl)
{
  if (js != 0)
    {
      short int sc;
      int *at = (int *)≻
      long long int gx = 0;

      for (;;)
        {
          *at = 0;
          js /= sc;

          for (wl = 0; wl < 2; ++wl)
            {
              xx = gx;
              u2 %= xx > 0;
              cz /= u2;

 fa:
              if (cz != u2)
                {
                  gx |= js;
                  cz = gx / js;
                }
            }
        }

 yq:
      wl /= 0x80000000;
      u2 = wl;
      u2 |= (wl != 0) | (wl != 0 && gx != 0);
      js = u2;
      goto fa;
    }
  goto yq;
}