[Bug fortran/33445] New: openmp invalid multi-thread runtime result (-ffree-form only!)

["fred2 at qnet dot com" <gcc-bugzilla at gcc dot gnu dot org>]

fortran code using openmp fails at runtime for multiple threads under
-ffree-form (but NOT -ffixed-form).
possibly due solely to treatment of continuation characters?

(tested only under gcc 4.1.2 (fedora core 7)

$ gcc -v
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
--disable-dssi --enable-plugin
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --enable-java-maintainer-mode
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --with-cpu=generic
--host=x86_64-redhat-linux
Thread model: posix
gcc version 4.1.2 20070502 (Red Hat 4.1.2-12)

error vs. compilation flags:

source_file     gfortran_flags          OMP_NUM_THREADS run_time_result
(stdout)

md.f            (none)                  N/A (serial)    ok
md.f            -fopenmp                1               ok
md.f            -fopenmp                2               ok

mdfree.f        -ffree-form             N/A (serial)    ok
mdfree.f        -fopenmp -ffree-form    1               ok
mdfree.f        -fopenmp -ffree-form    2               NaN

mdfree.f90      (none)                  N/A (serial)    ok
mdfree.f90      -fopenmp                1               ok
mdfree.f90      -fopenmp                2               NaN



md.f is from http://www.openmp.org/drupal/samples/md.html
(note: nsteps is reduced from 1000 to 100 to speed up testing).

mdfree.f replaces the fixed-form continuation characters (in column 6) w/
the free-form (&):

$ diff md.f mdfree.f
41,42c41,42
<       call compute(nparts,ndim,box,position,velocity,mass,
<      .                                      force,potential,kinetic)
---
>       call compute(nparts,ndim,box,position,velocity,mass, &
>                                             force,potential,kinetic)
47,48c47,48
<           call compute(nparts,ndim,box,position,velocity,mass,
<      .                                      force,potential,kinetic)
---
>           call compute(nparts,ndim,box,position,velocity,mass, &
>                                             force,potential,kinetic)

mdfree.f90 is just renamed mdfree.f.


-- 
           Summary: openmp invalid multi-thread runtime result (-ffree-form
                    only!)
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: fred2 at qnet dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33445