[Bug fortran/45425] Bounds check applied before MASK of WHERE construct

["burnus at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #1 from burnus at gcc dot gnu dot org  2010-08-27 11:58 -------
Confirm, the bounds checks are misplaces. Simplified test case:

implicit none
integer :: A(1), i,b(1)
logical :: mask(1)

mask = .false.
b = 5
do i = 2, 2
  where (mask)
    A = b(i)
  end where
end do
end



If one looks at the dump of the internal representation (-fdump-tree-original)
one sees that WHERE itself is properly handled - only the bounds check is
outside of the WHERE loop and thus outside of the MASK:

  if (__builtin_expect (i <= 0, 0))
    _gfortran_runtime_error_at (...);
[...]
              S.1 = 1;
              while (1)
                {
                  if (S.1 > 1) goto L.4;
                  if (mask[S.1 + -1])
                    {
                      a[S.1 + -1] = b[i + -1];
                    }
                  S.1 = S.1 + 1;
                }


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |27766
              nThis|                            |
           Keywords|                            |wrong-code
      Known to fail|                            |4.1.2 4.6.0
            Summary|where mask not applied      |Bounds check applied before
                   |before where clause         |MASK of WHERE construct
                   |evaluated                   |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45425