203   PetscInt        up, down, left, right, i, *idx, nn;  in DMSetUp_DA_2D()  local
373   nn = x * y;  in DMSetUp_DA_2D()
375   PetscCallMPI(MPI_Allgather(&nn, 1, MPIU_INT, ldims, 1, MPIU_INT, comm));  in DMSetUp_DA_2D()
529   nn    = 0;  in DMSetUp_DA_2D()
536       for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
543       for (j = 0; j < x_t; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
545       for (j = 0; j < x; j++) idx[nn++] = bases[rank] + x * (s_y - i + 1) + j;  in DMSetUp_DA_2D()
552       for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
561       for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
563       for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + x * i + s_x - j;  in DMSetUp_DA_2D()
566     for (j = 0; j < x; j++) idx[nn++] = xbase++; /* interior */  in DMSetUp_DA_2D()
572       for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
574       for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + x * (i + 1) - 2 - j;  in DMSetUp_DA_2D()
583       for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
590       for (j = 0; j < x_t; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
592       for (j = 0; j < x; j++) idx[nn++] = bases[rank] + x * (y - i - 1) + j;  in DMSetUp_DA_2D()
599       for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
603   PetscCall(ISCreateBlock(comm, dof, nn, idx, PETSC_USE_POINTER, &from));  in DMSetUp_DA_2D()
621     nn    = 0;  in DMSetUp_DA_2D()
628         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
630         for (j = 0; j < s_x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
636         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
639           for (j = 0; j < x; j++) idx[nn++] = bases[rank] + x * (s_y - i + 1) + j;  in DMSetUp_DA_2D()
641           for (j = 0; j < x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
648         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
650         for (j = 0; j < s_x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
659         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
662           for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + x * i + s_x - j;  in DMSetUp_DA_2D()
664           for (j = 0; j < s_x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
668       for (j = 0; j < x; j++) idx[nn++] = xbase++; /* interior */  in DMSetUp_DA_2D()
674         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
677           for (j = 0; j < s_x; j++) idx[nn++] = bases[rank] + x * (i + 1) - 2 - j;  in DMSetUp_DA_2D()
679           for (j = 0; j < s_x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
689         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
691         for (j = 0; j < s_x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
697         for (j = 0; j < x_t; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
700           for (j = 0; j < x; j++) idx[nn++] = bases[rank] + x * (y - i - 1) + j;  in DMSetUp_DA_2D()
702           for (j = 0; j < x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
709         for (j = 0; j < s_x; j++) idx[nn++] = s_t++;  in DMSetUp_DA_2D()
711         for (j = 0; j < s_x; j++) idx[nn++] = -1;  in DMSetUp_DA_2D()
719   PetscCall(ISLocalToGlobalMappingCreate(comm, dof, nn, idx, PETSC_OWN_POINTER, &da->ltogmap));  in DMSetUp_DA_2D()