Added support for parallel runs to geometry overlap checking

src/finalize.F90

@@ -36,6 +36,7 @@ contains
       if (output_tallies) then
         if (master) call write_tallies()
       end if
+      if (check_overlaps) call reduce_overlap_count()
     end if
 
 #ifdef PETSC
@@ -69,4 +70,22 @@ contains
 
   end subroutine finalize_run
 
+!===============================================================================
+! REDUCE_OVERLAP_COUNT accumulates cell overlap check counts to master
+!===============================================================================
+
+  subroutine reduce_overlap_count()
+
+#ifdef MPI
+      if (master) then
+        call MPI_REDUCE(MPI_IN_PLACE, overlap_check_cnt, n_cells, &
+             MPI_INTEGER8, MPI_SUM, 0, MPI_COMM_WORLD, mpi_err)
+      else
+        call MPI_REDUCE(overlap_check_cnt, overlap_check_cnt, n_cells, &
+             MPI_INTEGER8, MPI_SUM, 0, MPI_COMM_WORLD, mpi_err)
+      end if
+#endif
+
+  end subroutine reduce_overlap_count
+
 end module finalize

src/global.F90

@@ -275,8 +275,8 @@ module global
   integer :: verbosity = 7
 
   ! Flag for enabling cell overlap checking during transport
-  logical               :: check_overlaps = .false.
-  integer, allocatable  :: overlap_check_cnt(:)
+  logical                  :: check_overlaps = .false.
+  integer(8), allocatable  :: overlap_check_cnt(:)
 
   ! Trace for single particle
   logical    :: trace

src/initialize.F90

@@ -150,7 +150,7 @@ contains
     if (particle_restart_run) run_mode = MODE_PARTICLE
 
     ! Warn if overlap checking is on
-    if (check_overlaps) then
+    if (master .and. check_overlaps) then
       message = ""
       call write_message()
       message = "Cell overlap checking is ON"

src/output.F90

@@ -1504,7 +1504,7 @@ contains
     write(ou,*)
 
 100 format (1X,A,T15,A)
-101 format (1X,I8,T15,I8)
+101 format (1X,I8,T15,I12)
 
   end subroutine print_overlap_check