https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79430
--- Comment #33 from Thomas Koenig <tkoenig at gcc dot gnu.org> --- > Could you tell me how just to run a single testcase? Well, I figured that one out. Quite interesting, a different error with valgrind: | Events: event normalization mode '1' ==49974== Source and destination overlap in memcpy(0x7f3dae0, 0x7f3dae0, 176) ==49974== at 0x408B1A8: memcpy (in /usr/lib64/valgrind/vgpreload_memcheck-ppc64-linux.so) ==49974== by 0x441E1A7: __shower_core_MOD_shower_converttopythia (shower_core.f90:4010) ==49974== by 0x440C38B: __shower_core_MOD_shower_make_particle_set (shower_core.f90:451) ==49974== by 0x43E915B: __shower_MOD_evt_shower_make_particle_set (shower.f90:258) ==49974== by 0x43F49C3: __events_MOD_event_evaluate_transforms (events.f90:524) ==49974== by 0x43F3843: __events_MOD_event_generate (events.f90:751) ==49974== by 0x43739EF: __simulations_MOD_simulation_generate (simulations.f90:1639) ==49974== by 0x43992F7: __commands_MOD_cmd_simulate_execute (commands.f90:4501) ==49974== by 0x437CA6B: __commands_MOD_command_list_execute (commands.f90:5835) ==49974== by 0x43BD56B: __whizard_MOD_whizard_process_stream (whizard.f90:348) ==49974== by 0x43BCBF7: __whizard_MOD_whizard_process_file (whizard.f90:323) ==49974== by 0x40B547B: MAIN__ (main.f90:415) ==49974== The code there is temp_parton = final_partons(i + 1) final_partons(i + 1) = final_partons(j) final_partons(j) = temp_parton I have no idea if this is intended or not (if i + 1 is supposed to be identical to j) , but it points to a doubtful use of memcpy with gfortran which I will open a separate PR about.