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
