[Bug libfortran/31726] minloc/maxloc: wrong results with empty array (F2003 only)

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2007-04-27 13:16 -------
The problem is:
  if(0) { /* find index */
  else
        {
          pos.1 = 0;
        }
      D.1356 = (int4) ((<unnamed-unsigned:32>) pos.1 + 1);

As C and the internal tree have array indexes starting at one, the final index
has to be incremented by one. Thus "pos.1 = 0" is ok, but "+1" is only correct
if one has an index. The simplest would be to have "pos.1 = -1". Then one needs
to change trans-intrinsic.c's gfc_conv_intrinsic_minmaxloc:

  /* Initialize the position to zero, following Fortran 2003.  We are free
     to do this because Fortran 95 allows the result of an entirely false
     mask to be processor dependent.  */
  gfc_add_modify_expr (&loop.pre, pos, gfc_index_zero_node);

One should also check the library version of MIN/MAXLOC.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |wrong-code
   Last reconfirmed|0000-00-00 00:00:00         |2007-04-27 13:16:34
               date|                            |
            Summary|minloc/maxloc: wrong results|minloc/maxloc: wrong results
                   |with empty array            |with empty array (F2003
                   |                            |only)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31726