psblas:

base/comm/psb_dhalo.f90

@@ -49,6 +49,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine  psb_dhalom(x,desc_a,info,alpha,jx,ik,work,tran,mode,data)
@@ -274,6 +275,7 @@ end subroutine psb_dhalom
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine  psb_dhalov(x,desc_a,info,alpha,work,tran,mode,data)

base/comm/psb_ihalo.f90

@@ -50,6 +50,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine  psb_ihalom(x,desc_a,info,alpha,jx,ik,work,tran,mode,data)
@@ -278,6 +279,7 @@ end subroutine psb_ihalom
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine  psb_ihalov(x,desc_a,info,alpha,work,tran,mode,data)

base/comm/psb_zhalo.f90

@@ -49,6 +49,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine  psb_zhalom(x,desc_a,info,alpha,jx,ik,work,tran,mode,data)
@@ -275,6 +276,7 @@ end subroutine psb_zhalom
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine  psb_zhalov(x,desc_a,info,alpha,work,tran,mode,data)

base/internals/psi_crea_ovr_elem.f90

@@ -37,9 +37,9 @@
 !   See also description in base/modules/psb_desc_type.f90
 ! 
 ! Arguments: 
-!    ovr_elem(:) - integer, allocatable      Array containing the output list              
+!    ovr_elem(:,:) - integer, allocatable  Array containing the output list              
-!    desc_a   - type(psb_desc_type).    The communication descriptor.        
+!    desc_a   - type(psb_desc_type).       The communication descriptor.        
-!    info     - integer.                  return code.
+!    info     - integer.                   return code.
 ! 
 subroutine psi_crea_ovr_elem(me,desc_overlap,ovr_elem,info)
 

base/internals/psi_dswapdata.F90

@@ -77,6 +77,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 !
@@ -169,6 +170,12 @@ subroutine psi_dswapdatam(flag,n,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999
@@ -551,7 +558,7 @@ end subroutine psi_dswapdatam
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
-!
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 subroutine psi_dswapdatav(flag,beta,y,desc_a,work,info,data)
 
@@ -646,6 +653,12 @@ subroutine psi_dswapdatav(flag,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999

base/internals/psi_dswaptran.F90

@@ -81,6 +81,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_dswaptranm(flag,n,beta,y,desc_a,work,info,data)
@@ -172,6 +173,12 @@ subroutine psi_dswaptranm(flag,n,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999
@@ -554,6 +561,7 @@ end subroutine psi_dswaptranm
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_dswaptranv(flag,beta,y,desc_a,work,info,data)
@@ -649,6 +657,12 @@ subroutine psi_dswaptranv(flag,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     write(0,*) 'Really wrong?? ',data_, psb_comm_halo_, psb_comm_ovr_, psb_comm_ext_
     call psb_errpush(4010,name,a_err='wrong Data selector')

base/internals/psi_iswapdata.F90

@@ -77,6 +77,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_iswapdatam(flag,n,beta,y,desc_a,work,info,data)
@@ -168,6 +169,12 @@ subroutine psi_iswapdatam(flag,n,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999
@@ -550,6 +557,7 @@ end subroutine psi_iswapdatam
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_iswapdatav(flag,beta,y,desc_a,work,info,data)
@@ -645,6 +653,12 @@ subroutine psi_iswapdatav(flag,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999

base/internals/psi_iswaptran.F90

@@ -81,6 +81,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_iswaptranm(flag,n,beta,y,desc_a,work,info,data)
@@ -171,6 +172,12 @@ subroutine psi_iswaptranm(flag,n,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999
@@ -553,6 +560,7 @@ end subroutine psi_iswaptranm
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_iswaptranv(flag,beta,y,desc_a,work,info,data)
@@ -646,6 +654,12 @@ subroutine psi_iswaptranv(flag,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999

base/internals/psi_zswapdata.F90

@@ -77,6 +77,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_zswapdatam(flag,n,beta,y,desc_a,work,info,data)
@@ -168,6 +169,12 @@ subroutine psi_zswapdatam(flag,n,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999
@@ -550,6 +557,7 @@ end subroutine psi_zswapdatam
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_zswapdatav(flag,beta,y,desc_a,work,info,data)
@@ -645,6 +653,12 @@ subroutine psi_zswapdatav(flag,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999

base/internals/psi_zswaptran.F90

@@ -81,6 +81,7 @@
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_zswaptranm(flag,n,beta,y,desc_a,work,info,data)
@@ -172,6 +173,12 @@ subroutine psi_zswaptranm(flag,n,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999
@@ -554,6 +561,7 @@ end subroutine psi_zswaptranm
 !                                       psb_comm_halo_    use halo_index
 !                                       psb_comm_ext_     use ext_index 
 !                                       psb_comm_ovrl_    use ovrl_index
+!                                       psb_comm_mov_     use ovr_mst_idx
 !
 !
 subroutine psi_zswaptranv(flag,beta,y,desc_a,work,info,data)
@@ -648,6 +656,12 @@ subroutine psi_zswaptranv(flag,beta,y,desc_a,work,info,data)
     totxch = desc_a%matrix_data(psb_text_xch_)
     idxr   = desc_a%matrix_data(psb_text_rcv_)
     idxs   = desc_a%matrix_data(psb_text_snd_)
+
+  case(psb_comm_mov_) 
+    d_idx => desc_a%ovr_mst_idx
+    totxch = desc_a%matrix_data(psb_tmov_xch_)
+    idxr   = desc_a%matrix_data(psb_tmov_rcv_)
+    idxs   = desc_a%matrix_data(psb_tmov_snd_)
   case default
     call psb_errpush(4010,name,a_err='wrong Data selector')
     goto 9999

base/modules/psb_desc_type.f90

@@ -46,13 +46,15 @@ module psb_descriptor_type
   ! For overlap update. 
   integer, parameter :: psb_none_=0,  psb_sum_=1
   integer, parameter :: psb_avg_=2,  psb_square_root_=3
-  integer, parameter :: psb_zero_=999
+  integer, parameter :: psb_setzero_=4
+
   ! The following are bit fields. 
   integer, parameter :: psb_swap_send_=1, psb_swap_recv_=2
   integer, parameter :: psb_swap_sync_=4, psb_swap_mpi_=8
 
   integer, parameter :: psb_no_comm_=-1
-  integer, parameter :: psb_comm_halo_=1, psb_comm_ovr_=2, psb_comm_ext_=3
+  integer, parameter :: psb_comm_halo_=1, psb_comm_ovr_=2
+  integer, parameter :: psb_comm_ext_=3,  psb_comm_mov_=4
   integer, parameter :: psb_ovt_xhal_ = 123, psb_ovt_asov_=psb_ovt_xhal_+1
 
   !
@@ -71,7 +73,10 @@ module psb_descriptor_type
   integer, parameter :: psb_text_xch_=17
   integer, parameter :: psb_text_snd_=18
   integer, parameter :: psb_text_rcv_=19
-  integer, parameter :: psb_mdata_size_=20
+  integer, parameter :: psb_tmov_xch_=20
+  integer, parameter :: psb_tmov_snd_=21
+  integer, parameter :: psb_tmov_rcv_=22
+  integer, parameter :: psb_mdata_size_=24
   integer, parameter :: psb_desc_asb_=3099
   integer, parameter :: psb_desc_bld_=psb_desc_asb_+1
   integer, parameter :: psb_desc_repl_=3199
@@ -111,6 +116,7 @@ module psb_descriptor_type
   !|     integer, allocatable :: bnd_elem(:)
   !|     integer, allocatable :: ovrlap_index(:)
   !|     integer, allocatable :: ovrlap_elem(:,:)
+  !|     integer, allocatable :: ovr_mst_idx(:)
   !|     integer, allocatable :: loc_to_glob(:)
   !|     integer, allocatable :: glob_to_loc (:)
   !|     integer, allocatable :: hashv(:), glb_lc(:,:), ptree(:)
@@ -253,7 +259,14 @@ module psb_descriptor_type
   !     it only contains the end-of-list marker -1). 
   !
   ! 10. ovrlap_elem contains a list of overlap indices together with their degree
-  !     of overlap, i.e. the number of processes "owning" them.
+  !     of overlap, i.e. the number of processes "owning" the, and the "master"
+  !     process whose value has to be considered authoritative when the need arises.
+  !     
+  ! 11. ovr_mst_idx is a list defining a retrieve of a copy of the values for
+  !     overlap entries from their respecitve "master" processes by means of
+  !     an halo exchange call. This is used for those cases where there is
+  !     an overlap in the base data distribution.
+  !
   ! It is complex, but it does the following:
   !  1. Allows a purely local matrix/stencil buildup phase, requiring only 
   !     one synch point at the end (CDASB)
@@ -272,6 +285,7 @@ module psb_descriptor_type
      integer, allocatable :: bnd_elem(:)
      integer, allocatable :: ovrlap_index(:)
      integer, allocatable :: ovrlap_elem(:,:)
+     integer, allocatable :: ovr_mst_idx(:)
      integer, allocatable :: loc_to_glob(:)
      integer, allocatable :: glob_to_loc (:)
      integer, allocatable :: hashv(:), glb_lc(:,:), ptree(:)
@@ -305,6 +319,7 @@ contains
     if (allocated(desc%bnd_elem))     val = val + 4*size(desc%bnd_elem)
     if (allocated(desc%ovrlap_index)) val = val + 4*size(desc%ovrlap_index)
     if (allocated(desc%ovrlap_elem))  val = val + 4*size(desc%ovrlap_elem)
+    if (allocated(desc%ovr_mst_idx))  val = val + 4*size(desc%ovr_mst_idx)
     if (allocated(desc%loc_to_glob))  val = val + 4*size(desc%loc_to_glob)    
     if (allocated(desc%glob_to_loc))  val = val + 4*size(desc%glob_to_loc)
     if (allocated(desc%hashv))        val = val + 4*size(desc%hashv)

base/modules/psi_mod.f90

@@ -377,7 +377,7 @@ contains
     integer  :: np,me
     integer  :: ictxt, err_act,nxch,nsnd,nrcv,j,k
     !     ...local array...
-    integer, allocatable  :: idx_out(:)
+    integer, allocatable  :: idx_out(:), tmp_mst_idx(:)
 
     !     ...parameters
     integer :: debug_level, debug_unit
@@ -403,7 +403,7 @@ contains
     ! first the halo index
     if (debug_level>0) write(debug_unit,*) me,'Calling crea_index on halo'
     call psi_crea_index(cdesc,halo_in, idx_out,.false.,nxch,nsnd,nrcv,info)
-    if(info /= 0) then
+    if (info /= 0) then
       call psb_errpush(4010,name,a_err='psi_crea_index')
       goto 9999
     end if
@@ -419,7 +419,7 @@ contains
     ! then ext index
     if (debug_level>0) write(debug_unit,*) me,'Calling crea_index on ext'
     call psi_crea_index(cdesc,ext_in, idx_out,.false.,nxch,nsnd,nrcv,info)
-    if(info /= 0) then
+    if (info /= 0) then
       call psb_errpush(4010,name,a_err='psi_crea_index')
       goto 9999
     end if
@@ -433,12 +433,12 @@ contains
 
     ! then the overlap index
     call psi_crea_index(cdesc,ovrlap_in, idx_out,.true.,nxch,nsnd,nrcv,info)
-    if(info /= 0) then
+    if (info /= 0) then
       call psb_errpush(4010,name,a_err='psi_crea_index')
       goto 9999
     end if
     call psb_transfer(idx_out,cdesc%ovrlap_index,info)
-    if(info /= 0) then
+    if (info /= 0) then
       call psb_errpush(4010,name,a_err='psb_transfer')
       goto 9999
     end if
@@ -447,20 +447,39 @@ contains
     cdesc%matrix_data(psb_tovr_snd_) = nsnd
     cdesc%matrix_data(psb_tovr_rcv_) = nrcv 
 
-    if (debug_level>0) write(debug_unit,*) me,'Calling crea_ovr_elem'
     ! next  ovrlap_elem 
+    if (debug_level>0) write(debug_unit,*) me,'Calling crea_ovr_elem'
     call psi_crea_ovr_elem(me,cdesc%ovrlap_index,cdesc%ovrlap_elem,info)
     if (debug_level>0) write(debug_unit,*) me,'Done crea_ovr_elem'
-    if(info /= 0) then
+    if (info /= 0) then
       call psb_errpush(4010,name,a_err='psi_crea_ovr_elem')
       goto 9999
     end if
+    ! Extract ovr_mst_idx from ovrlap_elem 
+    if (debug_level>0) write(debug_unit,*) me,'Calling bld_ovr_mst'
+    call psi_bld_ovr_mst(me,cdesc%ovrlap_elem,tmp_mst_idx,info)
+    if (info == 0) call psi_crea_index(cdesc,&
+         & tmp_mst_idx,idx_out,.false.,nxch,nsnd,nrcv,info)
+    if (debug_level>0) write(debug_unit,*) me,'Done crea_indx'
+    if (info /= 0) then
+      call psb_errpush(4010,name,a_err='psi_bld_ovr_mst')
+      goto 9999
+    end if
+    call psb_transfer(idx_out,cdesc%ovr_mst_idx,info)
+    if (info /= 0) then
+      call psb_errpush(4010,name,a_err='psb_transfer')
+      goto 9999
+    end if
+
+    cdesc%matrix_data(psb_tmov_xch_) = nxch
+    cdesc%matrix_data(psb_tmov_snd_) = nsnd
+    cdesc%matrix_data(psb_tmov_rcv_) = nrcv 
 
     ! finally bnd_elem
     call psi_crea_bnd_elem(idx_out,cdesc,info)
     if (info == 0) call psb_transfer(idx_out,cdesc%bnd_elem,info)
 
-    if(info /= 0) then
+    if (info /= 0) then
       call psb_errpush(4010,name,a_err='psi_crea_bnd_elem')
       goto 9999
     end if
@@ -618,6 +637,12 @@ contains
         ndm = desc_a%ovrlap_elem(i,2)
         x(idx) = x(idx)/real(ndm)
       end do
+    case(psb_setzero_)
+      do i=1,size(desc_a%ovrlap_elem,1)
+        idx = desc_a%ovrlap_elem(i,1)
+        if (me /= desc_a%ovrlap_elem(i,3))&
+             & x(idx) = dzero
+      end do
     case(psb_sum_)
       ! do nothing
 
@@ -684,6 +709,12 @@ contains
         ndm = desc_a%ovrlap_elem(i,2)
         x(idx,:) = x(idx,:)/real(ndm)
       end do
+    case(psb_setzero_)
+      do i=1,size(desc_a%ovrlap_elem,1)
+        idx = desc_a%ovrlap_elem(i,1)
+        if (me /= desc_a%ovrlap_elem(i,3))&
+             & x(idx,:) = dzero
+      end do
     case(psb_sum_)
       ! do nothing
 
@@ -749,6 +780,12 @@ contains
         ndm = desc_a%ovrlap_elem(i,2)
         x(idx) = x(idx)/real(ndm)
       end do
+    case(psb_setzero_)
+      do i=1,size(desc_a%ovrlap_elem,1)
+        idx = desc_a%ovrlap_elem(i,1)
+        if (me /= desc_a%ovrlap_elem(i,3))&
+             & x(idx) = zzero
+      end do
     case(psb_sum_)
       ! do nothing
 
@@ -815,6 +852,12 @@ contains
         ndm = desc_a%ovrlap_elem(i,2)
         x(idx,:) = x(idx,:)/real(ndm)
       end do
+    case(psb_setzero_)
+      do i=1,size(desc_a%ovrlap_elem,1)
+        idx = desc_a%ovrlap_elem(i,1)
+        if (me /= desc_a%ovrlap_elem(i,3))&
+             & x(idx,:) = zzero
+      end do
     case(psb_sum_)
       ! do nothing
 
@@ -881,6 +924,12 @@ contains
         ndm = desc_a%ovrlap_elem(i,2)
         x(idx) = x(idx)/real(ndm)
       end do
+    case(psb_setzero_)
+      do i=1,size(desc_a%ovrlap_elem,1)
+        idx = desc_a%ovrlap_elem(i,1)
+        if (me /= desc_a%ovrlap_elem(i,3))&
+             & x(idx) = izero
+      end do
     case(psb_sum_)
       ! do nothing
 
@@ -948,6 +997,12 @@ contains
         ndm = desc_a%ovrlap_elem(i,2)
         x(idx,:) = x(idx,:)/real(ndm)
       end do
+    case(psb_setzero_)
+      do i=1,size(desc_a%ovrlap_elem,1)
+        idx = desc_a%ovrlap_elem(i,1)
+        if (me /= desc_a%ovrlap_elem(i,3))&
+             & x(idx,:) = izero
+      end do
     case(psb_sum_)
       ! do nothing
 
@@ -1935,6 +1990,59 @@ contains
       end do
     end if
   end subroutine psi_zsctv
+  
+  subroutine psi_bld_ovr_mst(me,ovrlap_elem,mst_idx,info)
+    use psb_const_mod
+    use psb_error_mod
+    use psb_penv_mod
+    use psb_descriptor_type
+    use psb_realloc_mod
+    implicit none
+
+    !     ....scalars parameters....
+    integer, intent(in)               :: me, ovrlap_elem(:,:)
+    integer, allocatable, intent(out) :: mst_idx(:) 
+    integer, intent(out)              :: info
+
+    integer  :: i, j, proc, nov,isz, ip, err_act, idx
+    character(len=20)  :: name
+
+    name='psi_bld_ovr_mst'
+    call psb_get_erraction(err_act)
+
+    nov = size(ovrlap_elem,1)
+    isz = 3*nov+1
+    call psb_realloc(isz,mst_idx,info) 
+    if (info /= 0) then
+      call psb_errpush(4001,name,a_err='reallocate')
+      goto 9999
+    end if
+    mst_idx = -1
+    j = 1
+    do i=1, nov
+      proc = ovrlap_elem(i,3)
+      if (me /= proc) then 
+        idx = ovrlap_elem(i,1)
+        mst_idx(j+0) = proc
+        mst_idx(j+1) = 1
+        mst_idx(j+2) = idx
+        j = j + 3
+      end if
+    end do
+    mst_idx(j) = -1 
+
+    call psb_erractionrestore(err_act)
+    return  
+
+9999 continue
+    call psb_erractionrestore(err_act)
+
+    if (err_act == psb_act_abort_) then
+      call psb_error()
+      return
+    end if
+    return
 
+  end subroutine psi_bld_ovr_mst
 
 end module psi_mod

base/tools/psb_cdcpy.f90

@@ -84,6 +84,7 @@ subroutine psb_cdcpy(desc_in, desc_out, info)
   if (info == 0)   call psb_safe_cpy(desc_in%ovrlap_index,desc_out%ovrlap_index,info)
   if (info == 0)   call psb_safe_cpy(desc_in%bnd_elem,desc_out%bnd_elem,info)
   if (info == 0)   call psb_safe_cpy(desc_in%ovrlap_elem,desc_out%ovrlap_elem,info)
+  if (info == 0)   call psb_safe_cpy(desc_in%ovr_mst_idx,desc_out%ovr_mst_idx,info)
   if (info == 0)   call psb_safe_cpy(desc_in%loc_to_glob,desc_out%loc_to_glob,info)
   if (info == 0)   call psb_safe_cpy(desc_in%glob_to_loc,desc_out%glob_to_loc,info)
   if (info == 0)   call psb_safe_cpy(desc_in%lprm,desc_out%lprm,info)

base/tools/psb_cdfree.f90

@@ -155,6 +155,14 @@ subroutine psb_cdfree(desc_a,info)
   end if
 
   !deallocate ovrlap_index  field
+  deallocate(desc_a%ovr_mst_idx,stat=info)
+  if (info /= 0) then
+    info=2055
+    call psb_errpush(info,name)
+    goto 9999
+  end if
+
+
   deallocate(desc_a%lprm,stat=info)
   if (info /= 0) then 
     info=2057

base/tools/psb_cdtransfer.f90

@@ -88,6 +88,8 @@ subroutine psb_cdtransfer(desc_in, desc_out, info)
        & call psb_transfer( desc_in%ovrlap_elem ,    desc_out%ovrlap_elem  , info)
   if (info == 0)  &
        & call psb_transfer( desc_in%ovrlap_index,    desc_out%ovrlap_index , info)
+  if (info == 0)  &
+       & call psb_transfer( desc_in%ovr_mst_idx ,    desc_out%ovr_mst_idx  , info)
   if (info == 0)  &
        & call psb_transfer( desc_in%ext_index   ,    desc_out%ext_index    , info)
   if (info == 0)  &

prec/psb_dbjac_aply.f90

@@ -122,7 +122,7 @@ subroutine psb_dbjac_aply(alpha,prec,x,beta,y,desc_data,trans,work,info)
       if(info /=0) goto 9999
 
     end select
-
+    
 
   case default
     info = 4001
@@ -130,6 +130,8 @@ subroutine psb_dbjac_aply(alpha,prec,x,beta,y,desc_data,trans,work,info)
     goto 9999
   end select
 
+  call psb_halo(y,desc_data,info,data=psb_comm_mov_)
+
   if (n_col <= size(work)) then 
     if ((4*n_col+n_col) <= size(work)) then 
     else

prec/psb_dprc_aply.f90

@@ -74,9 +74,6 @@ subroutine psb_dprc_aply(prec,x,y,desc_data,info,trans, work)
 
   call psb_gprec_aply(done,prec,x,dzero,y,desc_data,trans_,work_,info)
 
-  ! If the original distribution has an overlap we should fix that. 
-  call psb_ovrl(y,desc_data,info,update=psb_avg_)
-
   if (present(work)) then 
   else
     deallocate(work_)

prec/psb_zbjac_aply.f90

@@ -138,6 +138,8 @@ subroutine psb_zbjac_aply(alpha,prec,x,beta,y,desc_data,trans,work,info)
     goto 9999
   end select
 
+  call psb_halo(y,desc_data,info,data=psb_comm_mov_)
+
   if (n_col <= size(work)) then 
     if ((4*n_col+n_col) <= size(work)) then 
     else

prec/psb_zprc_aply.f90

@@ -76,7 +76,6 @@ subroutine psb_zprc_aply(prec,x,y,desc_data,info,trans, work)
   call psb_gprec_aply(zone,prec,x,zzero,y,desc_data,trans_,work_,info)
 
   ! If the original distribution has an overlap we should fix that. 
-  call psb_ovrl(y,desc_data,info,update=psb_avg_)
 
   if (present(work)) then 
   else