[Bug fortran/56503] Wrong compiler error message when compiling with default-real-8 option and using intrinsic dble

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56503

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |kargl at gcc dot gnu.org
         Resolution|                            |INVALID

--- Comment #1 from kargl at gcc dot gnu.org 2013-03-01 21:57:07 UTC ---
(In reply to comment #0)
> Hi!
> 
> I compile the little program beneath with 
> 'gfortran -fdefault-integer-8 -fdefault-real-8' command.
> 
> I get:
> 'call t1 ( dble(r4))
>           1
> Error: Type mismatch in argument 'r' at (1); passed REAL(16) to REAL(8) '
> 
> Since r4 is a single precision variable the dble should make a real*8 of it,
> or?

The error message says 'r' not 'r4'.  The 'r' here comes from
the explicit interface for t1, which has a declaration of 
real*8.  So, if you read the documentation that comes with
your compiler, you see that 'r' has been promoted to real*16.


`-fdefault-double-8'
     Set the `DOUBLE PRECISION' type to an 8 byte wide type.  If
     `-fdefault-real-8' is given, `DOUBLE PRECISION' would instead be
     promoted to 16 bytes if possible, and `-fdefault-double-8' can be
     used to prevent this.

You probably meant to use -freal-4-real-8.  I recommend using none 
of these options and actually writing properly ported code.