[Bug fortran/35743] allocate negative memory for zero-sized WHERE construct

["dominiq at lps dot ens dot fr" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #2 from dominiq at lps dot ens dot fr  2008-03-31 15:14 -------
The dump shows:

rg0025 (lda, nf1, nf2, nf3, nf5, nf6, mf1, mf2)
{
  integer(kind=4) ubound.9;
...
    D.979 = *nf6;
    D.980 = *nf3;
    D.981 = *nf6;
    D.982 = *nf3;
    D.983 = (1 - D.979) + *nf3;
    num.12 = D.983;
    D.986 = num.12;
    if (D.986 < 0)
      {
        _gfortran_runtime_error (&"Attempt to allocate a negative amount of
memory."[1]{lb: 1 sz: 1});
      }
...
      D.999 = *nf6;
      D.1000 = *nf2;
      D.1001 = *mf1;
      D.1002 = *nf5;
      D.1003 = *mf1;
      atmp.19.dtype = 297;
      atmp.19.dim[0].stride = 1;
      atmp.19.dim[0].lbound = 0;
      atmp.19.dim[0].ubound = *nf2 - D.999;
      D.1014 = (*nf2 - D.999) + 1 <= 0;
      D.1015 = (*nf2 - D.999) + 1;
      D.1016 = D.1014 ? 0 : D.1015 * 4;
      if (D.1016 < 0)
        {
          _gfortran_runtime_error (&"Attempt to allocate a negative amount of
memory."[1]{lb: 1 sz: 1});
        }
...
}

The size

    D.986 = num.12;

should have a check similar to

      D.1016 = D.1014 ? 0 : D.1015 * 4;

in order to avoid the runtime error.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35743