Take adjustable type into account.

src/ppm/ppm_graph_partition_mpi.f90

@@ -105,8 +105,9 @@ CONTAINS
     INTEGER(ppm_metis_idx), OPTIONAL, TARGET, INTENT(in) :: edge_weights(*)
     INTEGER(ppm_metis_int) :: wgtflag
     INTEGER :: part_comm, comm_size, comm_rank, ierror, i, ierror_
-    INTEGER, ALLOCATABLE :: vtxdist(:)
-    INTEGER(ppm_metis_int) :: metis_options(0:2), edge_cut, ncon, num_parts
+    INTEGER(ppm_metis_idx), ALLOCATABLE :: vtxdist(:)
+    INTEGER(ppm_metis_int) :: metis_options(0:2), edge_cut, ncon, num_parts, &
+         accum
     INTEGER :: msg_len
     CHARACTER(len=mpi_max_error_string) :: msg
     TYPE(c_ptr) :: vwgt, adjwgt
@@ -114,6 +115,7 @@ CONTAINS
 #ifndef HAVE_PARMETIS_V3
     REAL(ppm_metis_real), ALLOCATABLE, TARGET :: tpwgts_balance(:, :)
 #endif
+    INTEGER :: ppm_metis_idx_mpidt = mpi_datatype_null
 
     IF (PRESENT(comm)) THEN; part_comm = comm; ELSE; part_comm = mpi_comm_world
     END IF
@@ -131,19 +133,28 @@ CONTAINS
     ! build table of node distribution
     ALLOCATE(vtxdist(0:comm_size))
 
-    i = INT(num_vertices)
-    CALL mpi_allgather(i, 1, MPI_INTEGER, &
-         vtxdist(1:comm_size), 1, MPI_INTEGER, part_comm, ierror)
+    IF (ppm_metis_idx_mpidt == mpi_datatype_null) THEN
+      CALL mpi_type_create_f90_integer(RANGE(num_vertices), &
+           &                           ppm_metis_idx_mpidt, ierror)
+      IF (ierror /= MPI_SUCCESS) THEN
+        CALL mpi_error_string(ierror, msg, msg_len, ierror_)
+        CALL abort_ppm(msg(1:msg_len), filename, __LINE__, comm)
+      END IF
+    END IF
+    CALL mpi_allgather(num_vertices, 1, ppm_metis_idx_mpidt, &
+         vtxdist(1), 1, ppm_metis_idx_mpidt, part_comm, ierror)
     IF (ierror /= MPI_SUCCESS) then
       CALL mpi_error_string(ierror, msg, msg_len, ierror_)
       CALL abort_ppm(msg(1:msg_len), filename, __LINE__, comm)
     END IF
 
-    vtxdist(0) = 1
-    vtxdist(comm_rank + 1) = i
-    DO i = 1, comm_size
-      vtxdist(i) = vtxdist(i) + vtxdist(i - 1)
+    ! compute partial sums of vertices over ranks
+    accum = 1_ppm_metis_idx
+    DO i = 0, comm_size-1
+      vtxdist(i) = accum
+      accum = accum + vtxdist(i+1)
     END DO
+    vtxdist(comm_size) = accum
 
     wgtflag = 0
     IF (PRESENT(vertex_weights)) wgtflag = 2