diff -u -r a/EXAMPLE/EMCURV_Driver.f90 b/EXAMPLE/EMCURV_Driver.f90
--- a/EXAMPLE/EMCURV_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/EMCURV_Driver.f90	2020-07-13 10:55:08.000000000 +0900
@@ -71,6 +71,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	! nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/EXAMPLE/EMCURV_Eigen_Driver.f90 b/EXAMPLE/EMCURV_Eigen_Driver.f90
--- a/EXAMPLE/EMCURV_Eigen_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/EMCURV_Eigen_Driver.f90	2020-07-13 10:55:29.000000000 +0900
@@ -84,6 +84,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	! nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/EXAMPLE/EMCURV_Module.f90 b/EXAMPLE/EMCURV_Module.f90
--- a/EXAMPLE/EMCURV_Module.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/EMCURV_Module.f90	2020-07-13 16:32:29.000000000 +0900
@@ -23,6 +23,7 @@
 module EMCURV_MODULE
 use BPACK_DEFS
 use MISC_Utilities
+use service_routines,only:secnds
 implicit none
 
 	!**** define your application-related variables here
diff -u -r a/EXAMPLE/EMSURF_Driver.f90 b/EXAMPLE/EMSURF_Driver.f90
--- a/EXAMPLE/EMSURF_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/EMSURF_Driver.f90	2020-07-13 10:55:49.000000000 +0900
@@ -64,6 +64,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	! nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/EXAMPLE/EMSURF_Eigen_Driver.f90 b/EXAMPLE/EMSURF_Eigen_Driver.f90
--- a/EXAMPLE/EMSURF_Eigen_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/EMSURF_Eigen_Driver.f90	2020-07-13 10:56:08.000000000 +0900
@@ -82,6 +82,8 @@
 
 	integer nargs,flag
 
+	integer, external :: iargc
+
 	! nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/EXAMPLE/EMSURF_Module.f90 b/EXAMPLE/EMSURF_Module.f90
--- a/EXAMPLE/EMSURF_Module.f90	2020-07-16 17:39:15.000000000 +0900
+++ b/EXAMPLE/EMSURF_Module.f90	2020-07-13 16:34:10.000000000 +0900
@@ -23,6 +23,7 @@
 module EMSURF_MODULE
 use BPACK_DEFS
 use MISC_Utilities
+use service_routines,only:secnds
 implicit none
 
 	!**** define your application-related variables here
diff -u -r a/EXAMPLE/FrontalDist_Driver.f90 b/EXAMPLE/FrontalDist_Driver.f90
--- a/EXAMPLE/FrontalDist_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/FrontalDist_Driver.f90	2020-07-13 10:56:28.000000000 +0900
@@ -279,6 +279,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	! nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/EXAMPLE/Frontal_Driver.f90 b/EXAMPLE/Frontal_Driver.f90
--- a/EXAMPLE/Frontal_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/Frontal_Driver.f90	2020-07-13 10:56:40.000000000 +0900
@@ -272,6 +272,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	! nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/EXAMPLE/FULLMAT_Driver.f90 b/EXAMPLE/FULLMAT_Driver.f90
--- a/EXAMPLE/FULLMAT_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/FULLMAT_Driver.f90	2020-07-13 10:56:53.000000000 +0900
@@ -176,6 +176,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	!**** nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/EXAMPLE/FULLMATKERREG_Driver.f90 b/EXAMPLE/FULLMATKERREG_Driver.f90
--- a/EXAMPLE/FULLMATKERREG_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/FULLMATKERREG_Driver.f90	2020-07-13 16:35:24.000000000 +0900
@@ -22,6 +22,7 @@
 
 module APPLICATION_MODULE
 use BPACK_DEFS
+use service_routines,only:secnds
 implicit none
 
 	!**** define your application-related variables here
diff -u -r a/EXAMPLE/KERREG_Driver.f90 b/EXAMPLE/KERREG_Driver.f90
--- a/EXAMPLE/KERREG_Driver.f90	2020-07-13 09:36:52.000000000 +0900
+++ b/EXAMPLE/KERREG_Driver.f90	2020-07-13 16:39:05.000000000 +0900
@@ -22,6 +22,7 @@
 
 module APPLICATION_MODULE
 use BPACK_DEFS
+use service_routines,only:secnds
 implicit none
 
 	!**** define your application-related variables here
@@ -125,6 +126,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
 	allocate(groupmembers(nmpi))
diff -u -r a/EXAMPLE/SMAT_Driver.f90 b/EXAMPLE/SMAT_Driver.f90
--- a/EXAMPLE/SMAT_Driver.f90	2020-07-13 09:36:53.000000000 +0900
+++ b/EXAMPLE/SMAT_Driver.f90	2020-07-13 10:24:12.000000000 +0900
@@ -268,6 +268,8 @@
 	integer nargs,flag
 	integer v_major,v_minor,v_bugfix
 
+	integer, external :: iargc
+
 	! nmpi and groupmembers should be provided by the user
 	call MPI_Init(ierr)
 	call MPI_Comm_size(MPI_Comm_World,nmpi,ierr)
diff -u -r a/SRC/BPACK_constr.f90 b/SRC/BPACK_constr.f90
--- a/SRC/BPACK_constr.f90	2020-07-17 14:25:38.000000000 +0900
+++ b/SRC/BPACK_constr.f90	2020-07-13 09:25:41.000000000 +0900
@@ -1043,9 +1043,11 @@
 	curr=>lstr%head
 	curc=>lstc%head
 	do nn=1,Ninter
-	select type(ptrr=>curr%item)
+	ptrr=>curr%item
+	select type(ptrr)
 	type is(iarray)
-	select type(ptrc=>curc%item)
+	ptrc=>curc%item
+	select type(ptrc)
 	type is(iarray)
 		call Hmat_MapIntersec2Block_Loc(blocks_o,option,stats,msh,ptree,inters,nn,ptrr,ptrc,lstblk)
 	end select
@@ -1097,9 +1099,11 @@
 	curc=>blocks%lstc%head
 	allocate(blocks%inters(blocks%lstr%num_nods))
 	do nn=1,blocks%lstr%num_nods ! loop all lists of list of rows and columns
-	select type(ptrr=>curr%item)
+	ptrr=>curr%item
+	select type(ptrr)
 	type is (iarray)
-	select type(ptrc=>curc%item)
+	ptrc=>curc%item
+	select type(ptrc)
 	type is (iarray)
 		blocks%inters(nn)%nr=ptrr%num_nods
 		allocate(blocks%inters(nn)%rows(ptrr%num_nods))
@@ -1323,9 +1327,11 @@
 	curr=>lstr%head
 	curc=>lstc%head
 	do nn=1,Ninter
-	select type(ptrr=>curr%item)
+	ptrr=>curr%item
+	select type(ptrr)
 	type is(iarray)
-	select type(ptrc=>curc%item)
+	ptrc=>curc%item
+	select type(ptrc)
 	type is(iarray)
 		select case(option%format)
 		case(HODLR)
@@ -1383,9 +1389,11 @@
 	curc=>blocks%lstc%head
 	allocate(blocks%inters(blocks%lstr%num_nods))
 	do nn=1,blocks%lstr%num_nods ! loop all lists of list of rows and columns
-	select type(ptrr=>curr%item)
+	ptrr=>curr%item
+	select type(ptrr)
 	type is (iarray)
-	select type(ptrc=>curc%item)
+	ptrc=>curc%item
+	select type(ptrc)
 	type is (iarray)
 		blocks%inters(nn)%nr=ptrr%num_nods
 		allocate(blocks%inters(nn)%rows(ptrr%num_nods))
diff -u -r a/SRC/BPACK_defs.f90 b/SRC/BPACK_defs.f90
--- a/SRC/BPACK_defs.f90	2020-07-17 14:24:58.000000000 +0900
+++ b/SRC/BPACK_defs.f90	2020-07-10 17:25:39.000000000 +0900
@@ -245,7 +245,7 @@
          ! integer data_type  ! the block data_type, need better documentation later
 		 ! integer nested_num ! depreciated
 		 integer,allocatable :: ipiv(:)	! permutation of the LU of the dense diagonal blocks
-		 integer blockinfo_MPI(MPI_Header)
+		 integer blockinfo_MPI(MPI_Header) 
          integer length_Butterfly_index_MPI ! length of the index message, the first INDEX_Header integers are 1. decpreciated 2. rankmax 3. level_butterfly. 4. num_blocks
          integer length_Butterfly_data_MPI ! length of the value message
          DT,allocatable :: fullmat_MPI(:) ! massage for the dense blocks
@@ -379,7 +379,7 @@
 		integer forwardN15flag ! 1 use N^1.5 algorithm. 0: use NlogN pseudo skeleton algorithm
 		real(kind=8) tol_comp      ! matrix construction tolerance
 		integer::Nmin_leaf ! leaf sizes of HODLR tree
-		integer nogeo
+		integer nogeo 
 		integer xyzsort ! clustering methods given geometrical points: CKD: cartesian kd tree SKD: spherical kd tree (only for 3D points) TM: (2 mins no recursive)
 		integer::RecLR_leaf ! bottom level operations in a recursive merge-based LR compression: SVD, RRQR, ACA, BACA
 		real(kind=8):: near_para ! parameters used to determine whether two groups are nearfield or farfield pair
diff -u -r a/SRC/BPACK_utilities.f90 b/SRC/BPACK_utilities.f90
--- a/SRC/BPACK_utilities.f90	2020-07-10 16:23:52.000000000 +0900
+++ b/SRC/BPACK_utilities.f90	2020-07-13 09:06:56.000000000 +0900
@@ -478,6 +478,8 @@
 	integer nargs,flag
 	character(len=1024)  :: strings,strings1
 
+        integer, external :: iargc
+
 	nargs = iargc()
 	flag=1
 	do while(flag==1)
diff -u -r a/SRC/MISC_linkedlist.f90 b/SRC/MISC_linkedlist.f90
--- a/SRC/MISC_linkedlist.f90	2020-07-10 12:47:03.000000000 +0900
+++ b/SRC/MISC_linkedlist.f90	2020-07-10 15:43:40.000000000 +0900
@@ -283,8 +283,8 @@
 !    equal to the given complex value.
 !
 subroutine nod_assign_nod_to_nod( LHS, RHS )
-type(nod), intent(inout) :: LHS
-type(nod), intent(in) :: RHS
+type(nod), intent(inout), target :: LHS
+type(nod), intent(in), target :: RHS
 type(nod),pointer:: cur
 class(*),pointer :: ptrl,ptrr,ptr
 integer ii
@@ -300,9 +300,11 @@
 
 if(allocated(RHS%item))then
 	allocate(LHS%item, source=RHS%item)
-	select TYPE(ptrr=>RHS%item)
+	ptrr=>RHS%item
+	select TYPE(ptrr)
 		type is (list)
-			select TYPE(ptrl=>LHS%item)
+			ptrl=>LHS%item
+			select TYPE(ptrl)
 			type is (list)
 				ptrl%num_nods=0
 				ptrl%head=>null()