[Bug testsuite/120457] gcc.dg/vect/pr79920.c fail starting with r16-924-g1bc5b47f5b06dc

[liuhongt at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120457

--- Comment #1 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
double __attribute__((noinline,noclone))
compute_integral (double w_1[18])
{
  double A = 0;
  double t33[2][6] = {{0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
        {0.0, 0.0, 0.0, 0.0, 0.0, 0.0}};
  double t43[2] = {0.0, 0.0};
  double t31[2][2] = {{1.0, 1.0}, {1.0, 1.0}};
  double t32[2][3] = {{0.0, 0.0, 1.0}, {0.0, 0.0, 1.0}};

  for (int ip_1 = 0; ip_1 < 2; ++ip_1)
    {
#pragma GCC unroll 0
      for (int i_0 = 0; i_0 < 6; ++i_0)
        t33[ip_1][i_0] = ((w_1[i_0*3] * t32[ip_1][0])
                          + (w_1[i_0*3+2] * t32[ip_1][2]));  --- the loop is
not vectorized anymore for power
      t43[ip_1] = 2.0;
    }
  for (int i_0 = 0; i_0 < 6; ++i_0)
    A += t43[1]*t33[1][i_0];
  return A;
}