[Bug fortran/59026] New: ELEMENTAL procedure with VALUE arguments emits wrong code

fxcoudert at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Wed Nov 6 19:52:00 GMT 2013


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59026

            Bug ID: 59026
           Summary: ELEMENTAL procedure with VALUE arguments emits wrong
                    code
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fxcoudert at gcc dot gnu.org

The following source is compiled into wrong code:

interface
  elemental integer function foo(x)
    integer, intent(in), value :: x
  end function
end interface

  print *, foo(42)
  print *, foo([0,1])
end

For all versions of gfortran starting from 4.3 (and up to current trunk), the
second call to FOO is miscompiled. Looking at the generated code
(-fdump-tree-original), the first call is, as expected, by value:

      D.1882 = foo (42);
      _gfortran_transfer_integer_write (&dt_parm.0, &D.1882, 4);

while the second call is by-reference:

              D.1887 = A.2[S.3];
              D.1888 = foo (&D.1887);
              _gfortran_transfer_integer_write (&dt_parm.1, &D.1888, 4);

This can be confirmed by adding an actual FOO function such as:

elemental integer function foo(x)
  integer, intent(in), value :: x
  foo = x - 1
end function

Running the complete program then yields:

          41
  1370438451  1370438451



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