[Bug fortran/54923] New: Internal unit I/O error when using -malign-double

[Bug fortran/54923] New: Internal unit I/O error when using -malign-double

[gnu.0kn at gishpuppy dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54923

             Bug #: 54923
           Summary: Internal unit I/O error when using -malign-double
    Classification: Unclassified
           Product: gcc
           Version: 4.6.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gnu.0kn@gishpuppy.com


Reading from of integer from character string fails with 
Fortran runtime error: Internal unit I/O error
when compiling with -malign-double.

Background: This occurred when using the usual getarg(1,arg) construct and
linking against FFTW3, which requires data alignment.

Minimal example:
___

      PROGRAM readtest
      IMPLICIT NONE

      CHARACTER*8 arg
      INTEGER inputarg

      arg=" 1 "
      READ(arg,*) inputarg
      PRINT *,"Argument supplied was: ", inputarg

      RETURN
      END
___

Compiling with gfortran without data alignment yields the expected result.
Compiling with -malign-double in the compiler options yields runtime error.

Thank you.

[Bug fortran/54923] Internal unit I/O error when using -malign-double

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54923

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 2012-10-14 02:52:50 UTC ---
You need to compile all libraries with -malign-double.
This includes libgfortran.

[Bug fortran/54923] Internal unit I/O error when using -malign-double

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54923

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|INVALID                     |DUPLICATE

--- Comment #2 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-10-14 04:35:34 UTC ---
> You need to compile all libraries with -malign-double.
> This includes libgfortran.

For a more detailed explanation you may look at pr31696 or pr45724 (also
pr29562).

*** This bug has been marked as a duplicate of bug 31696 ***

[Bug fortran/54923] Internal unit I/O error when using -malign-double

[gnu.0kn at gishpuppy dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54923

--- Comment #3 from Drew <gnu.0kn at gishpuppy dot com> 2012-10-31 03:54:56 UTC ---
After some googling I have found that ABI means application binary interface
and how this affects the problem, thank you.

I would be happy if someone could direct me to a tutorial on how to maintain
two different ABIs on the same machine (so as not to break unaligned code
elsewhere) and how to obtain it precompiled from a package maintainer.

As another workaround, it has been indicated that $LD_PRELOAD may be used to
link to an aligned malloc

http://gcc.gnu.org/ml/fortran/2007-08/msg00320.html

For information on how to do either I, and I'm sure many others attempting to
call SSE functions or DMA transfers from 32 bit gfortran, would be very
thankful.