From 3cfc0c3ec08a1718da38bfff43544bbc3b25301f Mon Sep 17 00:00:00 2001
From: Salvatore Filippone <salvatore.filippone@cranfield.ac.uk>
Date: Wed, 12 Sep 2018 12:05:50 +0100
Subject: [PATCH] Add new files for BCMATCH tests.

---
 tests/Bcmatch/Makefile        |   46 ++
 tests/Bcmatch/data_input.f90  |  324 ++++++++++
 tests/Bcmatch/mld_d_pde3d.f90 | 1090 +++++++++++++++++++++++++++++++++
 3 files changed, 1460 insertions(+)
 create mode 100644 tests/Bcmatch/Makefile
 create mode 100644 tests/Bcmatch/data_input.f90
 create mode 100644 tests/Bcmatch/mld_d_pde3d.f90

diff --git a/tests/Bcmatch/Makefile b/tests/Bcmatch/Makefile
new file mode 100644
index 00000000..6cc8c8f6
--- /dev/null
+++ b/tests/Bcmatch/Makefile
@@ -0,0 +1,46 @@
+MLDDIR=../..
+MLDINCDIR=$(MLDDIR)/include
+include $(MLDINCDIR)/Make.inc.mld2p4
+MLDMODDIR=$(MLDDIR)/modules
+MLDLIBDIR=$(MLDDIR)/lib
+MLD_LIBS=-L$(MLDLIBDIR) -lpsb_krylov -lmld_prec -lpsb_prec
+FINCLUDES=$(FMFLAG). $(FMFLAG)$(MLDMODDIR) $(FMFLAG)$(MLDINCDIR) $(PSBLAS_INCLUDES) $(FIFLAG).
+
+LINKOPT=
+EXEDIR=./runs
+
+all: mld_s_pde3d mld_d_pde3d mld_s_pde2d mld_d_pde2d 
+
+mld_d_pde3d: mld_d_pde3d.o  data_input.o
+	$(FLINK) $(LINKOPT) mld_d_pde3d.o  data_input.o -o mld_d_pde3d $(MLD_LIBS) $(PSBLAS_LIBS) $(LDLIBS)
+	/bin/mv mld_d_pde3d $(EXEDIR)
+
+mld_s_pde3d: mld_s_pde3d.o   data_input.o
+	$(FLINK) $(LINKOPT) mld_s_pde3d.o  data_input.o -o mld_s_pde3d $(MLD_LIBS) $(PSBLAS_LIBS) $(LDLIBS)
+	/bin/mv mld_s_pde3d $(EXEDIR)
+
+mld_d_pde2d: mld_d_pde2d.o  data_input.o
+	$(FLINK) $(LINKOPT) mld_d_pde2d.o  data_input.o -o mld_d_pde2d $(MLD_LIBS) $(PSBLAS_LIBS) $(LDLIBS)
+	/bin/mv mld_d_pde2d $(EXEDIR)
+
+mld_s_pde2d: mld_s_pde2d.o   data_input.o
+	$(FLINK) $(LINKOPT) mld_s_pde2d.o  data_input.o -o mld_s_pde2d $(MLD_LIBS) $(PSBLAS_LIBS) $(LDLIBS)
+	/bin/mv mld_s_pde2d $(EXEDIR)
+
+mld_d_pde3d.o mld_s_pde3d.o mld_d_pde2d.o mld_s_pde2d.o: data_input.o 
+
+check: all
+	cd runs && ./mld_d_pde2d <mld_pde2d.inp && ./mld_s_pde2d<mld_pde2d.inp
+
+
+clean: 
+	/bin/rm -f data_input.o mld_d_pde3d.o mld_s_pde3d.o mld_d_pde2d.o mld_s_pde2d.o *$(.mod)\
+        $(EXEDIR)/mld_d_pde3d  $(EXEDIR)/mld_s_pde3d $(EXEDIR)/mld_d_pde2d  $(EXEDIR)/mld_s_pde2d 
+
+verycleanlib: 
+	(cd ../..; make veryclean)
+lib:
+	(cd ../../; make library)
+
+
+
diff --git a/tests/Bcmatch/data_input.f90 b/tests/Bcmatch/data_input.f90
new file mode 100644
index 00000000..b25cdeb0
--- /dev/null
+++ b/tests/Bcmatch/data_input.f90
@@ -0,0 +1,324 @@
+!   
+!   
+!                             MLD2P4  version 2.2
+!    MultiLevel Domain Decomposition Parallel Preconditioners Package
+!               based on PSBLAS (Parallel Sparse BLAS version 3.5)
+!    
+!    (C) Copyright 2008-2018 
+!  
+!        Salvatore Filippone  
+!        Pasqua D'Ambra   
+!        Daniela di Serafino   
+!   
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the MLD2P4 group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!   
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE MLD2P4 GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!   
+!  
+module data_input
+  use psb_base_mod, only : psb_spk_, psb_dpk_, psb_ipk_
+  
+  interface read_data
+    module procedure read_char, read_int, read_int_array,&
+         & read_double, read_double_array, &
+         & read_single, read_single_array, read_logical,&
+         & string_read_char, string_read_int, string_read_int_array,&
+         & string_read_double, string_read_double_array,&
+         & string_read_single, string_read_single_array, &
+         & string_read_logical
+  end interface read_data
+  interface trim_string
+    module procedure trim_string
+  end interface
+
+  character(len=4096), private  :: charbuf
+  character, private, parameter :: def_marker="!"
+  character, private, parameter :: cmt_marker="%"
+
+contains
+  subroutine get_buffer(file,buffer)
+    integer(psb_ipk_), intent(in)          :: file
+    character(len=*), intent(inout)        :: buffer
+    integer :: idx
+    do 
+      read(file,'(a)',end=999) buffer
+      buffer = adjustl(buffer)
+      idx=index(charbuf,cmt_marker)
+      if (idx == 1 ) then
+        cycle
+      else  
+        exit
+      end if      
+    end do
+999 continue
+    return
+  end subroutine get_buffer
+  
+  subroutine read_logical(val,file,marker)
+    logical, intent(out) :: val
+    integer(psb_ipk_), intent(in)          :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+
+  end subroutine read_logical
+
+  subroutine read_char(val,file,marker)
+    character(len=*), intent(out) :: val
+    integer(psb_ipk_), intent(in)           :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+
+  end subroutine read_char
+
+  subroutine read_int(val,file,marker)
+    integer(psb_ipk_), intent(out) :: val
+    integer(psb_ipk_), intent(in)  :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+
+  end subroutine read_int
+
+  subroutine read_int_array(val,file,marker)
+    integer(psb_ipk_), intent(out) :: val(:)
+    integer(psb_ipk_), intent(in)  :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+    
+  end subroutine read_int_array
+
+  subroutine read_single(val,file,marker)
+    real(psb_spk_), intent(out) :: val
+    integer(psb_ipk_), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+
+  end subroutine read_single
+
+  subroutine read_single_array(val,file,marker)
+    real(psb_spk_), intent(out) :: val(:)
+    integer(psb_ipk_), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+
+  end subroutine read_single_array
+
+  subroutine read_double(val,file,marker)
+    real(psb_dpk_), intent(out) :: val
+    integer(psb_ipk_), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+
+  end subroutine read_double
+
+  subroutine read_double_array(val,file,marker)
+    real(psb_dpk_), intent(out) :: val(:)
+    integer(psb_ipk_), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+
+    call get_buffer(file,charbuf)
+    call read_data(val,charbuf,marker)
+
+  end subroutine read_double_array
+
+  subroutine string_read_char(val,file,marker)
+    character(len=*), intent(out) :: val
+    character(len=*), intent(in)  :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),'(a)') val
+  end subroutine string_read_char
+
+  subroutine string_read_int(val,file,marker)
+    integer(psb_ipk_), intent(out) :: val
+    character(len=*), intent(in)  :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),*) val
+  end subroutine string_read_int
+
+  subroutine string_read_int_array(val,file,marker)
+    integer(psb_ipk_), intent(out) :: val(:)
+    character(len=*), intent(in)  :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),*) val(:)
+  end subroutine string_read_int_array
+
+  subroutine string_read_single(val,file,marker)
+    real(psb_spk_), intent(out) :: val
+    character(len=*), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),*) val
+  end subroutine string_read_single
+
+  subroutine string_read_single_array(val,file,marker)
+    real(psb_spk_), intent(out) :: val(:)
+    character(len=*), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),*) val(:)
+  end subroutine string_read_single_array
+
+  subroutine string_read_double(val,file,marker)
+    real(psb_dpk_), intent(out) :: val
+    character(len=*), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),*) val
+  end subroutine string_read_double
+
+  subroutine string_read_double_array(val,file,marker)
+    real(psb_dpk_), intent(out) :: val(:)
+    character(len=*), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),*) val(:)
+  end subroutine string_read_double_array
+
+  subroutine string_read_logical(val,file,marker)
+    logical, intent(out) :: val
+    character(len=*), intent(in)         :: file
+    character(len=1), optional, intent(in) :: marker
+    character(len=1)    :: marker_
+    character(len=1024) :: charbuf
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    read(file,'(a)')charbuf
+    charbuf = adjustl(charbuf)
+    idx=index(charbuf,marker_)
+    if (idx == 0) idx = len(charbuf)+1
+    read(charbuf(1:idx-1),*) val
+  end subroutine string_read_logical
+
+  function  trim_string(string,marker)
+    character(len=*), intent(in) :: string
+    character(len=1), optional, intent(in) :: marker
+    character(len=len(string))    :: trim_string
+    character(len=1)              :: marker_
+    integer(psb_ipk_) :: idx
+    if (present(marker)) then 
+      marker_ = marker
+    else
+      marker_ = def_marker
+    end if
+    idx=index(string,marker_)
+    trim_string = adjustl(string(idx:))
+  end function trim_string
+end module data_input
+
diff --git a/tests/Bcmatch/mld_d_pde3d.f90 b/tests/Bcmatch/mld_d_pde3d.f90
new file mode 100644
index 00000000..e8a85631
--- /dev/null
+++ b/tests/Bcmatch/mld_d_pde3d.f90
@@ -0,0 +1,1090 @@
+!   
+!   
+!                             MLD2P4  version 2.2
+!    MultiLevel Domain Decomposition Parallel Preconditioners Package
+!               based on PSBLAS (Parallel Sparse BLAS version 3.5)
+!    
+!    (C) Copyright 2008-2018 
+!  
+!        Salvatore Filippone  
+!        Pasqua D'Ambra   
+!        Daniela di Serafino   
+!   
+!    Redistribution and use in source and binary forms, with or without
+!    modification, are permitted provided that the following conditions
+!    are met:
+!      1. Redistributions of source code must retain the above copyright
+!         notice, this list of conditions and the following disclaimer.
+!      2. Redistributions in binary form must reproduce the above copyright
+!         notice, this list of conditions, and the following disclaimer in the
+!         documentation and/or other materials provided with the distribution.
+!      3. The name of the MLD2P4 group or the names of its contributors may
+!         not be used to endorse or promote products derived from this
+!         software without specific written permission.
+!   
+!    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+!    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+!    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+!    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE MLD2P4 GROUP OR ITS CONTRIBUTORS
+!    BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+!    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+!    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+!    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+!    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+!    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+!    POSSIBILITY OF SUCH DAMAGE.
+!   
+!    
+!
+! File: mld_d_pde3d.f90
+!
+! Program: mld_d_pde3d
+! This sample program solves a linear system obtained by discretizing a
+! PDE with Dirichlet BCs. 
+! 
+!
+! The PDE is a general second order equation in 3d
+!
+!   a1 dd(u)  a2 dd(u)    a3 dd(u)    b1 d(u)   b2 d(u)  b3 d(u)  
+! -   ------ -  ------ -  ------ +  -----  +  ------  +  ------ + c u = f
+!      dxdx     dydy       dzdz        dx       dy         dz   
+!
+! with Dirichlet boundary conditions
+!   u = g 
+!
+!  on the unit cube  0<=x,y,z<=1.
+!
+!
+! Note that if b1=b2=b3=c=0., the PDE is the  Laplace equation.
+!
+! There are three choices available for data distribution:
+! 1. A simple BLOCK distribution
+! 2. A ditribution based on arbitrary assignment of indices to processes,
+!    typically from a graph partitioner
+! 3. A 3D distribution in which the unit cube is partitioned
+!    into subcubes, each one assigned to a process.
+!
+module mld_d_pde3d_mod
+  use psb_base_mod, only : psb_dpk_, psb_ipk_, psb_desc_type,&
+       &  psb_dspmat_type, psb_d_vect_type, dzero,&
+       &  psb_d_base_sparse_mat, psb_d_base_vect_type, psb_i_base_vect_type
+
+  interface 
+    function d_func_3d(x,y,z) result(val)
+      import :: psb_dpk_
+      real(psb_dpk_), intent(in) :: x,y,z
+      real(psb_dpk_) :: val
+    end function d_func_3d
+  end interface 
+
+  interface mld_gen_pde3d
+    module procedure  mld_d_gen_pde3d
+  end interface mld_gen_pde3d
+
+  
+contains
+
+  function d_null_func_3d(x,y,z) result(val)
+
+    real(psb_dpk_), intent(in) :: x,y,z
+    real(psb_dpk_) :: val
+    
+    val = dzero
+
+  end function d_null_func_3d
+  !
+  ! functions parametrizing the differential equation 
+  !  
+
+  !
+  ! Note: b1, b2 and b3 are the coefficients of the first
+  ! derivative of the unknown function. The default
+  ! we apply here is to have them zero, so that the resulting
+  ! matrix is symmetric/hermitian and suitable for
+  ! testing with CG and FCG.
+  ! When testing methods for non-hermitian matrices you can
+  ! change the B1/B2/B3 functions to e.g. done/sqrt((3*done))
+  !
+  function b1(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) :: b1
+    real(psb_dpk_), intent(in) :: x,y,z
+    b1=dzero
+  end function b1
+  function b2(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) ::  b2
+    real(psb_dpk_), intent(in) :: x,y,z
+    b2=dzero
+  end function b2
+  function b3(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) ::  b3
+    real(psb_dpk_), intent(in) :: x,y,z      
+    b3=dzero
+  end function b3
+  function c(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) ::  c
+    real(psb_dpk_), intent(in) :: x,y,z      
+    c=dzero
+  end function c
+  function a1(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) ::  a1   
+    real(psb_dpk_), intent(in) :: x,y,z
+    a1=done/80
+  end function a1
+  function a2(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) ::  a2
+    real(psb_dpk_), intent(in) :: x,y,z
+    a2=done/80
+  end function a2
+  function a3(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) ::  a3
+    real(psb_dpk_), intent(in) :: x,y,z
+    a3=done/80
+  end function a3
+  function g(x,y,z)
+    use psb_base_mod, only : psb_dpk_, done, dzero
+    implicit none 
+    real(psb_dpk_) ::  g
+    real(psb_dpk_), intent(in) :: x,y,z
+    g = dzero
+    if (x == done) then
+      g = done
+    else if (x == dzero) then 
+      g = exp(y**2-z**2)
+    end if
+  end function g
+
+  
+  !
+  !  subroutine to allocate and fill in the coefficient matrix and
+  !  the rhs. 
+  !
+  subroutine mld_d_gen_pde3d(ictxt,idim,a,bv,xv,desc_a,afmt,info,&
+       & f,amold,vmold,imold,partition,nrl,iv)
+    use psb_base_mod
+    use psb_util_mod
+    !
+    !   Discretizes the partial differential equation
+    ! 
+    !   a1 dd(u)  a2 dd(u)    a3 dd(u)    b1 d(u)   b2 d(u)  b3 d(u)  
+    ! -   ------ -  ------ -  ------ +  -----  +  ------  +  ------ + c u = f
+    !      dxdx     dydy       dzdz        dx       dy         dz   
+    !
+    ! with Dirichlet boundary conditions
+    !   u = g 
+    !
+    !  on the unit cube  0<=x,y,z<=1.
+    !
+    !
+    ! Note that if b1=b2=b3=c=0., the PDE is the  Laplace equation.
+    !
+    implicit none
+    integer(psb_ipk_)     :: idim
+    type(psb_dspmat_type) :: a
+    type(psb_d_vect_type) :: xv,bv
+    type(psb_desc_type)   :: desc_a
+    integer(psb_ipk_)     :: ictxt, info
+    character(len=*)      :: afmt
+    procedure(d_func_3d), optional :: f
+    class(psb_d_base_sparse_mat), optional :: amold
+    class(psb_d_base_vect_type), optional :: vmold 
+    class(psb_i_base_vect_type), optional :: imold
+    integer(psb_ipk_), optional :: partition, nrl,iv(:)
+
+    ! Local variables.
+
+    integer(psb_ipk_), parameter :: nb=20
+    type(psb_d_csc_sparse_mat)  :: acsc
+    type(psb_d_coo_sparse_mat)  :: acoo
+    type(psb_d_csr_sparse_mat)  :: acsr
+    real(psb_dpk_)           :: zt(nb),x,y,z
+    integer(psb_ipk_) :: m,n,nnz,nr,nt,glob_row,nlr,i,j,ii,ib,k, partition_
+    integer(psb_ipk_) :: ix,iy,iz,ia,indx_owner
+    ! For 3D partition
+    integer(psb_ipk_) :: npx,npy,npz, npdims(3),iamx,iamy,iamz,mynx,myny,mynz
+    integer(psb_ipk_), allocatable :: bndx(:),bndy(:),bndz(:)
+    ! Process grid
+    integer(psb_ipk_) :: np, iam
+    integer(psb_ipk_) :: icoeff
+    integer(psb_ipk_), allocatable     :: irow(:),icol(:),myidx(:)
+    real(psb_dpk_), allocatable :: val(:)
+    ! deltah dimension of each grid cell
+    ! deltat discretization time
+    real(psb_dpk_)            :: deltah, sqdeltah, deltah2
+    real(psb_dpk_), parameter :: rhs=dzero,one=done,zero=dzero
+    real(psb_dpk_)    :: t0, t1, t2, t3, tasb, talc, ttot, tgen, tcdasb
+    integer(psb_ipk_) :: err_act
+    procedure(d_func_3d), pointer :: f_
+    character(len=20)  :: name, ch_err,tmpfmt
+
+    info = psb_success_
+    name = 'create_matrix'
+    call psb_erractionsave(err_act)
+
+    call psb_info(ictxt, iam, np)
+
+
+    if (present(f)) then 
+      f_ => f
+    else
+      f_ => d_null_func_3d
+    end if
+
+    deltah   = done/(idim+2)
+    sqdeltah = deltah*deltah
+    deltah2  = (2*done)* deltah
+
+    if (present(partition)) then
+      if ((1<= partition).and.(partition <= 3)) then
+        partition_ = partition
+      else
+        write(*,*) 'Invalid partition choice ',partition,' defaulting to 3'
+        partition_ = 3
+      end if
+    else
+      partition_ = 3
+    end if
+    
+    ! initialize array descriptor and sparse matrix storage. provide an
+    ! estimate of the number of non zeroes 
+    
+    m   = idim*idim*idim
+    n   = m
+    nnz = ((n*7)/(np))
+    if(iam == psb_root_) write(psb_out_unit,'("Generating Matrix (size=",i0,")...")')n
+    t0 = psb_wtime()
+    select case(partition_)
+    case(1)
+      ! A BLOCK partition 
+      if (present(nrl)) then 
+        nr = nrl
+      else
+        !
+        ! Using a simple BLOCK distribution.
+        !
+        nt = (m+np-1)/np
+        nr = max(0,min(nt,m-(iam*nt)))
+      end if
+
+      nt = nr
+      call psb_sum(ictxt,nt) 
+      if (nt /= m) then 
+        write(psb_err_unit,*) iam, 'Initialization error ',nr,nt,m
+        info = -1
+        call psb_barrier(ictxt)
+        call psb_abort(ictxt)
+        return    
+      end if
+
+      !
+      ! First example  of use of CDALL: specify for each process a number of
+      ! contiguous rows
+      ! 
+      call psb_cdall(ictxt,desc_a,info,nl=nr)
+      myidx = desc_a%get_global_indices()
+      nlr = size(myidx)
+
+    case(2)
+      ! A  partition  defined by the user through IV
+      
+      if (present(iv)) then 
+        if (size(iv) /= m) then
+          write(psb_err_unit,*) iam, 'Initialization error: wrong IV size',size(iv),m
+          info = -1
+          call psb_barrier(ictxt)
+          call psb_abort(ictxt)
+          return    
+        end if
+      else
+        write(psb_err_unit,*) iam, 'Initialization error: IV not present'
+        info = -1
+        call psb_barrier(ictxt)
+        call psb_abort(ictxt)
+        return    
+      end if
+
+      !
+      ! Second example  of use of CDALL: specify for each row the
+      ! process that owns it 
+      ! 
+      call psb_cdall(ictxt,desc_a,info,vg=iv)
+      myidx = desc_a%get_global_indices()
+      nlr = size(myidx)
+
+    case(3)
+      ! A 3-dimensional partition
+
+      ! A nifty MPI function will split the process list
+      npdims = 0
+      call mpi_dims_create(np,3,npdims,info)
+      npx = npdims(1)
+      npy = npdims(2)
+      npz = npdims(3)
+
+      allocate(bndx(0:npx),bndy(0:npy),bndz(0:npz))
+      ! We can reuse idx2ijk for process indices as well. 
+      call idx2ijk(iamx,iamy,iamz,iam,npx,npy,npz,base=0)
+      ! Now let's split the 3D cube in hexahedra
+      call dist1Didx(bndx,idim,npx)
+      mynx = bndx(iamx+1)-bndx(iamx)
+      call dist1Didx(bndy,idim,npy)
+      myny = bndy(iamy+1)-bndy(iamy)
+      call dist1Didx(bndz,idim,npz)
+      mynz = bndz(iamz+1)-bndz(iamz)
+
+      ! How many indices do I own? 
+      nlr = mynx*myny*mynz
+      allocate(myidx(nlr))
+      ! Now, let's generate the list of indices I own
+      nr = 0
+      do i=bndx(iamx),bndx(iamx+1)-1
+        do j=bndy(iamy),bndy(iamy+1)-1
+          do k=bndz(iamz),bndz(iamz+1)-1
+            nr = nr + 1
+            call ijk2idx(myidx(nr),i,j,k,idim,idim,idim)
+          end do
+        end do
+      end do
+      if (nr /= nlr) then
+        write(psb_err_unit,*) iam,iamx,iamy,iamz, 'Initialization error: NR vs NLR ',&
+             & nr,nlr,mynx,myny,mynz
+        info = -1
+        call psb_barrier(ictxt)
+        call psb_abort(ictxt)
+      end if
+
+      !
+      ! Third example  of use of CDALL: specify for each process
+      ! the set of global indices it owns.
+      ! 
+      call psb_cdall(ictxt,desc_a,info,vl=myidx)
+      
+    case default
+      write(psb_err_unit,*) iam, 'Initialization error: should not get here'
+      info = -1
+      call psb_barrier(ictxt)
+      call psb_abort(ictxt)
+      return
+    end select
+
+    
+    if (info == psb_success_) call psb_spall(a,desc_a,info,nnz=nnz)
+    ! define  rhs from boundary conditions; also build initial guess 
+    if (info == psb_success_) call psb_geall(xv,desc_a,info)
+    if (info == psb_success_) call psb_geall(bv,desc_a,info)
+
+    call psb_barrier(ictxt)
+    talc = psb_wtime()-t0
+
+    if (info /= psb_success_) then
+      info=psb_err_from_subroutine_
+      ch_err='allocation rout.'
+      call psb_errpush(info,name,a_err=ch_err)
+      goto 9999
+    end if
+
+    ! we build an auxiliary matrix consisting of one row at a
+    ! time; just a small matrix. might be extended to generate 
+    ! a bunch of rows per call. 
+    ! 
+    allocate(val(20*nb),irow(20*nb),&
+         &icol(20*nb),stat=info)
+    if (info /= psb_success_ ) then 
+      info=psb_err_alloc_dealloc_
+      call psb_errpush(info,name)
+      goto 9999
+    endif
+
+
+    ! loop over rows belonging to current process in a block
+    ! distribution.
+
+    call psb_barrier(ictxt)
+    t1 = psb_wtime()
+    do ii=1, nlr,nb
+      ib = min(nb,nlr-ii+1) 
+      icoeff = 1
+      do k=1,ib
+        i=ii+k-1
+        ! local matrix pointer 
+        glob_row=myidx(i)
+        ! compute gridpoint coordinates
+        call idx2ijk(ix,iy,iz,glob_row,idim,idim,idim)
+        ! x, y, z coordinates
+        x = (ix-1)*deltah
+        y = (iy-1)*deltah
+        z = (iz-1)*deltah
+        zt(k) = f_(x,y,z)
+        ! internal point: build discretization
+        !   
+        !  term depending on   (x-1,y,z)
+        !
+        val(icoeff) = -a1(x,y,z)/sqdeltah-b1(x,y,z)/deltah2
+        if (ix == 1) then 
+          zt(k) = g(dzero,y,z)*(-val(icoeff)) + zt(k)
+        else
+          call ijk2idx(icol(icoeff),ix-1,iy,iz,idim,idim,idim)
+          irow(icoeff) = glob_row
+          icoeff       = icoeff+1
+        endif
+        !  term depending on     (x,y-1,z)
+        val(icoeff)  = -a2(x,y,z)/sqdeltah-b2(x,y,z)/deltah2
+        if (iy == 1) then 
+          zt(k) = g(x,dzero,z)*(-val(icoeff))   + zt(k)
+        else
+          call ijk2idx(icol(icoeff),ix,iy-1,iz,idim,idim,idim)          
+          irow(icoeff) = glob_row
+          icoeff       = icoeff+1
+        endif
+        !  term depending on     (x,y,z-1)
+        val(icoeff)=-a3(x,y,z)/sqdeltah-b3(x,y,z)/deltah2
+        if (iz == 1) then 
+          zt(k) = g(x,y,dzero)*(-val(icoeff))   + zt(k)
+        else
+          call ijk2idx(icol(icoeff),ix,iy,iz-1,idim,idim,idim)          
+          irow(icoeff) = glob_row
+          icoeff       = icoeff+1
+        endif
+
+        !  term depending on     (x,y,z)
+        val(icoeff)=(2*done)*(a1(x,y,z)+a2(x,y,z)+a3(x,y,z))/sqdeltah &
+             & + c(x,y,z)
+        call ijk2idx(icol(icoeff),ix,iy,iz,idim,idim,idim)          
+        irow(icoeff) = glob_row
+        icoeff       = icoeff+1                  
+        !  term depending on     (x,y,z+1)
+        val(icoeff)=-a3(x,y,z)/sqdeltah+b3(x,y,z)/deltah2
+        if (iz == idim) then 
+          zt(k) = g(x,y,done)*(-val(icoeff))   + zt(k)
+        else
+          call ijk2idx(icol(icoeff),ix,iy,iz+1,idim,idim,idim)          
+          irow(icoeff) = glob_row
+          icoeff       = icoeff+1
+        endif
+        !  term depending on     (x,y+1,z)
+        val(icoeff)=-a2(x,y,z)/sqdeltah+b2(x,y,z)/deltah2
+        if (iy == idim) then 
+          zt(k) = g(x,done,z)*(-val(icoeff))   + zt(k)
+        else
+          call ijk2idx(icol(icoeff),ix,iy+1,iz,idim,idim,idim)          
+          irow(icoeff) = glob_row
+          icoeff       = icoeff+1
+        endif
+        !  term depending on     (x+1,y,z)
+        val(icoeff)=-a1(x,y,z)/sqdeltah+b1(x,y,z)/deltah2
+        if (ix==idim) then 
+          zt(k) = g(done,y,z)*(-val(icoeff))   + zt(k)
+        else
+          call ijk2idx(icol(icoeff),ix+1,iy,iz,idim,idim,idim)          
+          irow(icoeff) = glob_row
+          icoeff       = icoeff+1
+        endif
+
+      end do
+      call psb_spins(icoeff-1,irow,icol,val,a,desc_a,info)
+      if(info /= psb_success_) exit
+      call psb_geins(ib,myidx(ii:ii+ib-1),zt(1:ib),bv,desc_a,info)
+      if(info /= psb_success_) exit
+      zt(:)=dzero
+      call psb_geins(ib,myidx(ii:ii+ib-1),zt(1:ib),xv,desc_a,info)
+      if(info /= psb_success_) exit
+    end do
+
+    tgen = psb_wtime()-t1
+    if(info /= psb_success_) then
+      info=psb_err_from_subroutine_
+      ch_err='insert rout.'
+      call psb_errpush(info,name,a_err=ch_err)
+      goto 9999
+    end if
+
+    deallocate(val,irow,icol)
+
+    call psb_barrier(ictxt)
+    t1 = psb_wtime()
+    call psb_cdasb(desc_a,info,mold=imold)
+    tcdasb = psb_wtime()-t1
+    call psb_barrier(ictxt)
+    t1 = psb_wtime()
+    if (info == psb_success_) then 
+      if (present(amold)) then 
+        call psb_spasb(a,desc_a,info,dupl=psb_dupl_err_,mold=amold)
+      else
+        call psb_spasb(a,desc_a,info,dupl=psb_dupl_err_,afmt=afmt)
+      end if
+    end if
+    call psb_barrier(ictxt)
+    if(info /= psb_success_) then
+      info=psb_err_from_subroutine_
+      ch_err='asb rout.'
+      call psb_errpush(info,name,a_err=ch_err)
+      goto 9999
+    end if
+    if (info == psb_success_) call psb_geasb(xv,desc_a,info,mold=vmold)
+    if (info == psb_success_) call psb_geasb(bv,desc_a,info,mold=vmold)
+    if(info /= psb_success_) then
+      info=psb_err_from_subroutine_
+      ch_err='asb rout.'
+      call psb_errpush(info,name,a_err=ch_err)
+      goto 9999
+    end if
+    tasb = psb_wtime()-t1
+    call psb_barrier(ictxt)
+    ttot = psb_wtime() - t0 
+
+    call psb_amx(ictxt,talc)
+    call psb_amx(ictxt,tgen)
+    call psb_amx(ictxt,tasb)
+    call psb_amx(ictxt,ttot)
+    if(iam == psb_root_) then
+      tmpfmt = a%get_fmt()
+      write(psb_out_unit,'("The matrix has been generated and assembled in ",a3," format.")')&
+           &   tmpfmt
+      write(psb_out_unit,'("-allocation  time : ",es12.5)') talc
+      write(psb_out_unit,'("-coeff. gen. time : ",es12.5)') tgen
+      write(psb_out_unit,'("-desc asbly  time : ",es12.5)') tcdasb
+      write(psb_out_unit,'("- mat asbly  time : ",es12.5)') tasb
+      write(psb_out_unit,'("-total       time : ",es12.5)') ttot
+
+    end if
+    call psb_erractionrestore(err_act)
+    return
+
+9999 call psb_error_handler(ictxt,err_act)
+
+    return
+  end subroutine mld_d_gen_pde3d
+
+end module mld_d_pde3d_mod
+
+program mld_d_pde3d
+  use psb_base_mod
+  use mld_prec_mod
+  use psb_krylov_mod
+  use psb_util_mod
+  use data_input
+  use mld_d_pde3d_mod
+  implicit none
+
+  ! input parameters
+  character(len=20) :: kmethd, ptype
+  character(len=5)  :: afmt
+  integer(psb_ipk_) :: idim
+
+  ! miscellaneous 
+  real(psb_dpk_) :: t1, t2, tprec, thier, tslv
+
+  ! sparse matrix and preconditioner
+  type(psb_dspmat_type) :: a
+  type(mld_dprec_type)  :: prec
+  ! descriptor
+  type(psb_desc_type)   :: desc_a
+  ! dense vectors
+  type(psb_d_vect_type) :: x,b,r
+  ! parallel environment
+  integer(psb_ipk_) :: ictxt, iam, np
+
+  ! solver parameters
+  integer(psb_ipk_)        :: iter, itmax,itrace, istopc, irst, nlv
+  integer(psb_long_int_k_) :: amatsize, precsize, descsize
+  real(psb_dpk_)   :: err, resmx, resmxp
+
+  ! Krylov solver data
+  type solverdata
+    character(len=40)  :: kmethd      ! Krylov solver
+    integer(psb_ipk_)  :: istopc      ! stopping criterion
+    integer(psb_ipk_)  :: itmax       ! maximum number of iterations
+    integer(psb_ipk_)  :: itrace      ! tracing
+    integer(psb_ipk_)  :: irst        ! restart
+    real(psb_dpk_)     :: eps         ! stopping tolerance
+  end type solverdata
+  type(solverdata)       :: s_choice
+
+  ! preconditioner data
+  type precdata
+
+    ! preconditioner type
+    character(len=40)  :: descr       ! verbose description of the prec
+    character(len=10)  :: ptype       ! preconditioner type
+
+    integer(psb_ipk_)  :: outer_sweeps ! number of outer sweeps: sweeps for 1-level,
+                                       ! AMG cycles for ML
+    ! general AMG data
+    character(len=16)  :: mlcycle      ! AMG cycle type
+    integer(psb_ipk_)  :: maxlevs     ! maximum number of levels in AMG preconditioner
+
+    ! AMG aggregation
+    character(len=16)  :: aggr_prol    ! aggregation type: SMOOTHED, NONSMOOTHED
+    character(len=16)  :: par_aggr_alg    ! parallel aggregation algorithm: DEC, SYMDEC
+    character(len=16)  :: aggr_ord    ! ordering for aggregation: NATURAL, DEGREE
+    character(len=16)  :: aggr_filter ! filtering: FILTER, NO_FILTER
+    real(psb_dpk_)     :: mncrratio  ! minimum aggregation ratio
+    real(psb_dpk_), allocatable :: athresv(:) ! smoothed aggregation threshold vector
+    integer(psb_ipk_)  :: thrvsz      ! size of threshold vector
+    real(psb_dpk_)     :: athres      ! smoothed aggregation threshold
+    integer(psb_ipk_)  :: csize       ! minimum size of coarsest matrix
+
+    ! AMG smoother or pre-smoother; also 1-lev preconditioner
+    character(len=16)  :: smther      ! (pre-)smoother type: BJAC, AS
+    integer(psb_ipk_)  :: jsweeps     ! (pre-)smoother / 1-lev prec. sweeps
+    integer(psb_ipk_)  :: novr        ! number of overlap layers
+    character(len=16)  :: restr       ! restriction over application of AS
+    character(len=16)  :: prol        ! prolongation over application of AS
+    character(len=16)  :: solve       ! local subsolver type: ILU, MILU, ILUT,
+                                      ! UMF, MUMPS, SLU, FWGS, BWGS, JAC
+    integer(psb_ipk_)  :: fill        ! fill-in for incomplete LU factorization
+    real(psb_dpk_)     :: thr         ! threshold for ILUT factorization
+
+    ! AMG post-smoother; ignored by 1-lev preconditioner
+    character(len=16)  :: smther2     ! post-smoother type: BJAC, AS
+    integer(psb_ipk_)  :: jsweeps2    ! post-smoother sweeps
+    integer(psb_ipk_)  :: novr2       ! number of overlap layers
+    character(len=16)  :: restr2      ! restriction  over application of AS
+    character(len=16)  :: prol2       ! prolongation over application of AS
+    character(len=16)  :: solve2      ! local subsolver type: ILU, MILU, ILUT,
+                                      ! UMF, MUMPS, SLU, FWGS, BWGS, JAC
+    integer(psb_ipk_)  :: fill2       ! fill-in for incomplete LU factorization
+    real(psb_dpk_)     :: thr2        ! threshold for ILUT factorization
+
+    ! coarsest-level solver
+    character(len=16)  :: cmat        ! coarsest matrix layout: REPL, DIST
+    character(len=16)  :: csolve      ! coarsest-lev solver: BJAC, SLUDIST (distr.
+                                      ! mat.); UMF, MUMPS, SLU, ILU, ILUT, MILU
+                                      ! (repl. mat.)
+    character(len=16)  :: csbsolve    ! coarsest-lev local subsolver: ILU, ILUT,
+                                      ! MILU, UMF, MUMPS, SLU
+    integer(psb_ipk_)  :: cfill       ! fill-in for incomplete LU factorization
+    real(psb_dpk_)     :: cthres      ! threshold for ILUT factorization
+    integer(psb_ipk_)  :: cjswp       ! sweeps for GS or JAC coarsest-lev subsolver
+
+  end type precdata
+  type(precdata)       :: p_choice
+
+  ! other variables
+  integer(psb_ipk_)  :: info, i, k
+  character(len=20)  :: name,ch_err
+
+  info=psb_success_
+
+
+  call psb_init(ictxt)
+  call psb_info(ictxt,iam,np)
+
+  if (iam < 0) then 
+    ! This should not happen, but just in case
+    call psb_exit(ictxt)
+    stop
+  endif
+  if(psb_get_errstatus() /= 0) goto 9999
+  name='mld_d_pde3d'
+  call psb_set_errverbosity(itwo)
+  !
+  ! Hello world
+  !
+  if (iam == psb_root_) then 
+    write(*,*) 'Welcome to MLD2P4 version: ',mld_version_string_
+    write(*,*) 'This is the ',trim(name),' sample program'
+  end if
+
+  !
+  !  get parameters
+  !
+  call get_parms(ictxt,afmt,idim,s_choice,p_choice)
+
+  !
+  !  allocate and fill in the coefficient matrix, rhs and initial guess 
+  !
+
+  call psb_barrier(ictxt)
+  t1 = psb_wtime()
+  call mld_gen_pde3d(ictxt,idim,a,b,x,desc_a,afmt,info)  
+  call psb_barrier(ictxt)
+  t2 = psb_wtime() - t1
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='mld_gen_pde3d'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+
+  if (iam == psb_root_) &
+       & write(psb_out_unit,'("Overall matrix creation time : ",es12.5)')t2
+  if (iam == psb_root_) &
+       & write(psb_out_unit,'(" ")')
+  !
+  ! initialize the preconditioner
+  !
+  call prec%init(p_choice%ptype,info)
+  select case(trim(psb_toupper(p_choice%ptype)))
+  case ('NONE','NOPREC')
+    ! Do nothing, keep defaults
+
+  case ('JACOBI','GS','FWGS','FBGS')
+    ! 1-level sweeps from "outer_sweeps"
+    call prec%set('smoother_sweeps', p_choice%jsweeps, info)
+    
+  case ('BJAC')
+    call prec%set('smoother_sweeps', p_choice%jsweeps, info)
+    call prec%set('sub_solve',       p_choice%solve,   info)
+    call prec%set('sub_fillin',      p_choice%fill,    info)
+    call prec%set('sub_iluthrs',     p_choice%thr,     info)
+
+  case('AS')
+    call prec%set('smoother_sweeps', p_choice%jsweeps, info)
+    call prec%set('sub_ovr',         p_choice%novr,    info)
+    call prec%set('sub_restr',       p_choice%restr,   info)
+    call prec%set('sub_prol',        p_choice%prol,    info)
+    call prec%set('sub_solve',       p_choice%solve,   info)
+    call prec%set('sub_fillin',      p_choice%fill,    info)
+    call prec%set('sub_iluthrs',     p_choice%thr,     info)
+    
+  case ('ML') 
+    ! multilevel preconditioner
+
+    call prec%set('ml_cycle',        p_choice%mlcycle,    info)
+    call prec%set('outer_sweeps',    p_choice%outer_sweeps,info)
+    if (p_choice%csize>0)&
+         & call prec%set('min_coarse_size', p_choice%csize,      info)
+    if (p_choice%mncrratio>1)&
+         & call prec%set('min_cr_ratio',   p_choice%mncrratio, info)
+    if (p_choice%maxlevs>0)&
+         & call prec%set('max_levs',    p_choice%maxlevs,    info)
+    if (p_choice%athres >= dzero) &
+         & call prec%set('aggr_thresh',     p_choice%athres,  info)
+    if (p_choice%thrvsz>0) then
+      do k=1,min(p_choice%thrvsz,size(prec%precv)-1)
+        call prec%set('aggr_thresh',     p_choice%athresv(k),  info,ilev=(k+1))
+      end do
+    end if
+
+    call prec%set('aggr_prol',       p_choice%aggr_prol,   info)
+    call prec%set('par_aggr_alg',    p_choice%par_aggr_alg,   info)
+    call prec%set('aggr_ord',        p_choice%aggr_ord,   info)
+    call prec%set('aggr_filter',     p_choice%aggr_filter,info)
+
+
+    call prec%set('smoother_type',   p_choice%smther,     info)
+    call prec%set('smoother_sweeps', p_choice%jsweeps,    info)
+
+    select case (psb_toupper(p_choice%smther))
+    case ('GS','BWGS','FBGS','JACOBI')
+      ! do nothing
+    case default
+      call prec%set('sub_ovr',         p_choice%novr,       info)
+      call prec%set('sub_restr',       p_choice%restr,      info)
+      call prec%set('sub_prol',        p_choice%prol,       info)
+      call prec%set('sub_solve',       p_choice%solve,      info)
+      call prec%set('sub_fillin',      p_choice%fill,       info)
+      call prec%set('sub_iluthrs',     p_choice%thr,        info)
+    end select
+
+    if (psb_toupper(p_choice%smther2) /= 'NONE') then
+      call prec%set('smoother_type',   p_choice%smther2,   info,pos='post')
+      call prec%set('smoother_sweeps', p_choice%jsweeps2,  info,pos='post')
+      select case (psb_toupper(p_choice%smther2))
+      case ('GS','BWGS','FBGS','JACOBI')
+        ! do nothing
+      case default
+        call prec%set('sub_ovr',         p_choice%novr2,     info,pos='post')
+        call prec%set('sub_restr',       p_choice%restr2,    info,pos='post')
+        call prec%set('sub_prol',        p_choice%prol2,     info,pos='post')
+        call prec%set('sub_solve',       p_choice%solve2,    info,pos='post')
+        call prec%set('sub_fillin',      p_choice%fill2,     info,pos='post')
+        call prec%set('sub_iluthrs',     p_choice%thr2,      info,pos='post')
+      end select
+    end if
+
+    call prec%set('coarse_solve',    p_choice%csolve,    info)
+    if (psb_toupper(p_choice%csolve) == 'BJAC') &
+         &  call prec%set('coarse_subsolve', p_choice%csbsolve,  info)
+    call prec%set('coarse_mat',      p_choice%cmat,      info)
+    call prec%set('coarse_fillin',   p_choice%cfill,     info)
+    call prec%set('coarse_iluthrs',  p_choice%cthres,    info)
+    call prec%set('coarse_sweeps',   p_choice%cjswp,     info)
+
+  end select
+  
+  ! build the preconditioner
+  call psb_barrier(ictxt)
+  t1 = psb_wtime()
+  call prec%hierarchy_build(a,desc_a,info)
+  thier = psb_wtime()-t1
+  if (info /= psb_success_) then
+    call psb_errpush(psb_err_from_subroutine_,name,a_err='mld_hierarchy_bld')
+    goto 9999
+  end if
+  call psb_barrier(ictxt)
+  t1 = psb_wtime()
+  call prec%smoothers_build(a,desc_a,info)
+  tprec = psb_wtime()-t1
+  if (info /= psb_success_) then
+    call psb_errpush(psb_err_from_subroutine_,name,a_err='mld_smoothers_bld')
+    goto 9999
+  end if
+
+  call psb_amx(ictxt, thier)
+  call psb_amx(ictxt, tprec)
+
+  if(iam == psb_root_) then
+    write(psb_out_unit,'(" ")')
+    write(psb_out_unit,'("Preconditioner: ",a)') trim(p_choice%descr)
+    write(psb_out_unit,'("Preconditioner time: ",es12.5)')thier+tprec
+    write(psb_out_unit,'(" ")')
+  end if
+
+  !
+  ! iterative method parameters 
+  !
+  call psb_barrier(ictxt)
+  t1 = psb_wtime()
+  call psb_krylov(s_choice%kmethd,a,prec,b,x,s_choice%eps,&
+       & desc_a,info,itmax=s_choice%itmax,iter=iter,err=err,itrace=s_choice%itrace,&
+       & istop=s_choice%istopc,irst=s_choice%irst)
+  call psb_barrier(ictxt)
+  tslv = psb_wtime() - t1
+
+  call psb_amx(ictxt,tslv)
+
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='solver routine'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+
+  call psb_barrier(ictxt)
+  tslv = psb_wtime() - t1
+  call psb_amx(ictxt,tslv)
+
+  ! compute residual norms
+  call psb_geall(r,desc_a,info)
+  call r%zero()
+  call psb_geasb(r,desc_a,info)
+  call psb_geaxpby(done,b,dzero,r,desc_a,info)
+  call psb_spmm(-done,a,x,done,r,desc_a,info)
+  resmx  = psb_genrm2(r,desc_a,info)
+  resmxp = psb_geamax(r,desc_a,info)
+
+  amatsize = a%sizeof()
+  descsize = desc_a%sizeof()
+  precsize = prec%sizeof()
+  call psb_sum(ictxt,amatsize)
+  call psb_sum(ictxt,descsize)
+  call psb_sum(ictxt,precsize)
+  call prec%descr(iout=psb_out_unit)
+  if (iam == psb_root_) then 
+    write(psb_out_unit,'("Computed solution on ",i8," processors")')  np
+    write(psb_out_unit,'("Krylov method                      : ",a)') trim(s_choice%kmethd)
+    write(psb_out_unit,'("Preconditioner                     : ",a)') trim(p_choice%descr)
+    write(psb_out_unit,'("Iterations to convergence          : ",i12)')    iter
+    write(psb_out_unit,'("Relative error estimate on exit    : ",es12.5)') err
+    write(psb_out_unit,'("Number of levels in hierarchy      : ",i12)')    prec%get_nlevs()
+    write(psb_out_unit,'("Time to build hierarchy            : ",es12.5)') thier
+    write(psb_out_unit,'("Time to build smoothers            : ",es12.5)') tprec
+    write(psb_out_unit,'("Total time for preconditioner      : ",es12.5)') tprec+thier
+    write(psb_out_unit,'("Time to solve system               : ",es12.5)') tslv
+    write(psb_out_unit,'("Time per iteration                 : ",es12.5)') tslv/iter
+    write(psb_out_unit,'("Total time                         : ",es12.5)') tslv+tprec+thier
+    write(psb_out_unit,'("Residual 2-norm                    : ",es12.5)') resmx
+    write(psb_out_unit,'("Residual inf-norm                  : ",es12.5)') resmxp
+    write(psb_out_unit,'("Total memory occupation for A      : ",i12)') amatsize
+    write(psb_out_unit,'("Total memory occupation for DESC_A : ",i12)') descsize
+    write(psb_out_unit,'("Total memory occupation for PREC   : ",i12)') precsize
+    write(psb_out_unit,'("Storage format for A               : ",a  )') a%get_fmt()
+    write(psb_out_unit,'("Storage format for DESC_A          : ",a  )') desc_a%get_fmt()
+
+  end if
+
+  !  
+  !  cleanup storage and exit
+  !
+  call psb_gefree(b,desc_a,info)
+  call psb_gefree(x,desc_a,info)
+  call psb_spfree(a,desc_a,info)
+  call prec%free(info)
+  call psb_cdfree(desc_a,info)
+  if(info /= psb_success_) then
+    info=psb_err_from_subroutine_
+    ch_err='free routine'
+    call psb_errpush(info,name,a_err=ch_err)
+    goto 9999
+  end if
+  call psb_exit(ictxt)
+  stop
+
+9999 continue
+  call psb_error(ictxt)
+
+contains
+  !
+  ! get iteration parameters from standard input
+  !
+  !
+  ! get iteration parameters from standard input
+  !
+  subroutine get_parms(icontxt,afmt,idim,solve,prec)
+
+    use psb_base_mod
+    implicit none
+
+    integer(psb_ipk_)   :: icontxt, idim
+    character(len=*)    :: afmt
+    type(solverdata)    :: solve
+    type(precdata)      :: prec
+    integer(psb_ipk_)   :: iam, nm, np, inp_unit
+    character(len=1024)   :: filename
+
+    call psb_info(icontxt,iam,np)
+
+    if (iam == psb_root_) then
+      if (command_argument_count()>0) then
+        call get_command_argument(1,filename)
+        inp_unit = 30
+        open(inp_unit,file=filename,action='read',iostat=info)
+        if (info /= 0) then
+          write(psb_err_unit,*) 'Could not open file ',filename,' for input'
+          call psb_abort(icontxt)
+          stop
+        else
+          write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
+        end if
+      else
+        inp_unit=psb_inp_unit
+      end if
+      ! read input data
+      !
+      call read_data(afmt,inp_unit)            ! matrix storage format
+      call read_data(idim,inp_unit)            ! Discretization grid size
+      ! Krylov solver data
+      call read_data(solve%kmethd,inp_unit)    ! Krylov solver
+      call read_data(solve%istopc,inp_unit)    ! stopping criterion
+      call read_data(solve%itmax,inp_unit)     ! max num iterations
+      call read_data(solve%itrace,inp_unit)    ! tracing
+      call read_data(solve%irst,inp_unit)      ! restart
+      call read_data(solve%eps,inp_unit)       ! tolerance
+      ! preconditioner type
+      call read_data(prec%descr,inp_unit)      ! verbose description of the prec
+      call read_data(prec%ptype,inp_unit)      ! preconditioner type
+      ! First smoother / 1-lev preconditioner
+      call read_data(prec%smther,inp_unit)     ! smoother type
+      call read_data(prec%jsweeps,inp_unit)    ! (pre-)smoother / 1-lev prec sweeps
+      call read_data(prec%novr,inp_unit)       ! number of overlap layers
+      call read_data(prec%restr,inp_unit)      ! restriction  over application of AS
+      call read_data(prec%prol,inp_unit)       ! prolongation over application of AS
+      call read_data(prec%solve,inp_unit)      ! local subsolver
+      call read_data(prec%fill,inp_unit)       ! fill-in for incomplete LU
+      call read_data(prec%thr,inp_unit)        ! threshold for ILUT
+      ! Second smoother/ AMG post-smoother (if NONE ignored in main)
+      call read_data(prec%smther2,inp_unit)     ! smoother type
+      call read_data(prec%jsweeps2,inp_unit)    ! (post-)smoother sweeps
+      call read_data(prec%novr2,inp_unit)       ! number of overlap layers
+      call read_data(prec%restr2,inp_unit)      ! restriction  over application of AS
+      call read_data(prec%prol2,inp_unit)       ! prolongation over application of AS
+      call read_data(prec%solve2,inp_unit)      ! local subsolver
+      call read_data(prec%fill2,inp_unit)       ! fill-in for incomplete LU
+      call read_data(prec%thr2,inp_unit)        ! threshold for ILUT
+      ! general AMG data
+      call read_data(prec%mlcycle,inp_unit)     ! AMG cycle type
+      call read_data(prec%outer_sweeps,inp_unit) ! number of 1lev/outer sweeps
+      call read_data(prec%maxlevs,inp_unit)    ! max number of levels in AMG prec
+      call read_data(prec%csize,inp_unit)       ! min size coarsest mat
+      ! aggregation
+      call read_data(prec%aggr_prol,inp_unit)    ! aggregation type
+      call read_data(prec%par_aggr_alg,inp_unit)    ! parallel aggregation alg
+      call read_data(prec%aggr_ord,inp_unit)    ! ordering for aggregation
+      call read_data(prec%aggr_filter,inp_unit) ! filtering
+      call read_data(prec%mncrratio,inp_unit)  ! minimum aggregation ratio
+      call read_data(prec%thrvsz,inp_unit)      ! size of aggr thresh vector
+      if (prec%thrvsz > 0) then
+        call psb_realloc(prec%thrvsz,prec%athresv,info)
+        call read_data(prec%athresv,inp_unit)   ! aggr thresh vector
+      else
+        read(inp_unit,*)                        ! dummy read to skip a record
+      end if
+      call read_data(prec%athres,inp_unit)      ! smoothed aggr thresh
+      ! coasest-level solver
+      call read_data(prec%csolve,inp_unit)      ! coarsest-lev solver
+      call read_data(prec%csbsolve,inp_unit)    ! coarsest-lev subsolver
+      call read_data(prec%cmat,inp_unit)        ! coarsest mat layout
+      call read_data(prec%cfill,inp_unit)       ! fill-in for incompl LU
+      call read_data(prec%cthres,inp_unit)      ! Threshold for ILUT
+      call read_data(prec%cjswp,inp_unit)       ! sweeps for GS/JAC subsolver
+      if (inp_unit /= psb_inp_unit) then
+        close(inp_unit)
+      end if
+    end if
+
+    call psb_bcast(icontxt,afmt)
+    call psb_bcast(icontxt,idim)
+
+    call psb_bcast(icontxt,solve%kmethd)
+    call psb_bcast(icontxt,solve%istopc)
+    call psb_bcast(icontxt,solve%itmax)
+    call psb_bcast(icontxt,solve%itrace)
+    call psb_bcast(icontxt,solve%irst)
+    call psb_bcast(icontxt,solve%eps)
+
+    call psb_bcast(icontxt,prec%descr)
+    call psb_bcast(icontxt,prec%ptype)
+
+    ! broadcast first (pre-)smoother / 1-lev prec data
+    call psb_bcast(icontxt,prec%smther)     
+    call psb_bcast(icontxt,prec%jsweeps)
+    call psb_bcast(icontxt,prec%novr)
+    call psb_bcast(icontxt,prec%restr)
+    call psb_bcast(icontxt,prec%prol)
+    call psb_bcast(icontxt,prec%solve)
+    call psb_bcast(icontxt,prec%fill)
+    call psb_bcast(icontxt,prec%thr)
+    ! broadcast second (post-)smoother 
+    call psb_bcast(icontxt,prec%smther2)
+    call psb_bcast(icontxt,prec%jsweeps2)
+    call psb_bcast(icontxt,prec%novr2)
+    call psb_bcast(icontxt,prec%restr2)
+    call psb_bcast(icontxt,prec%prol2)
+    call psb_bcast(icontxt,prec%solve2)
+    call psb_bcast(icontxt,prec%fill2)
+    call psb_bcast(icontxt,prec%thr2)
+    
+    ! broadcast AMG parameters
+    call psb_bcast(icontxt,prec%mlcycle)
+    call psb_bcast(icontxt,prec%outer_sweeps)
+    call psb_bcast(icontxt,prec%maxlevs)
+    
+    call psb_bcast(icontxt,prec%aggr_prol)
+    call psb_bcast(icontxt,prec%par_aggr_alg)
+    call psb_bcast(icontxt,prec%aggr_ord)
+    call psb_bcast(icontxt,prec%aggr_filter)
+    call psb_bcast(icontxt,prec%mncrratio)
+    call psb_bcast(ictxt,prec%thrvsz)
+    if (prec%thrvsz > 0) then
+      if (iam /= psb_root_) call psb_realloc(prec%thrvsz,prec%athresv,info)
+      call psb_bcast(ictxt,prec%athresv)
+    end if
+    call psb_bcast(ictxt,prec%athres)
+    
+    call psb_bcast(icontxt,prec%csize)
+    call psb_bcast(icontxt,prec%cmat)
+    call psb_bcast(icontxt,prec%csolve)
+    call psb_bcast(icontxt,prec%csbsolve)
+    call psb_bcast(icontxt,prec%cfill)
+    call psb_bcast(icontxt,prec%cthres)
+    call psb_bcast(icontxt,prec%cjswp)
+
+
+  end subroutine get_parms
+
+end program mld_d_pde3d