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psblas3/base/modules/serial/psb_d_nest_base_mat_mod.F90

1194 lines
51 KiB
Fortran

!
! Parallel Sparse BLAS version 3.5
! (C) Copyright 2006-2018
! Salvatore Filippone
! Alfredo Buttari
!
! 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 PSBLAS group or the names of its contributors may
! not be used to endorse or promote products derived from this
! software without specific prior 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 PSBLAS 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: psb_d_nest_base_mat_mod.F90
!
! Module: psb_d_nest_base_mat_mod
! Author: Simone Staccone (Stack-1)
!
! Adapter that makes a block-structured (nested) operator look like a standard
! local sparse matrix to PSBLAS: psb_d_nest_base_mat EXTENDS
! psb_d_base_sparse_mat and implements csmv (the local matrix-vector product).
! Wrapped in a psb_dspmat_type and paired with the composed global descriptor
! (see psb_cd_nest_compose), the nested operator can then be fed to psb_spmm,
! psb_krylov and the AMG4PSBLAS preconditioners unchanged (MATNEST-style).
!
! The local vector handed to csmv lives in the GLOBAL local layout produced by
! psb_cd_nest_compose: the owned entries of all fields are concatenated, followed
! by the global halo. For each field we precompute field_map(field)%global_local_pos,
! the positions in that global local vector of the field's own local vector
! (owned entries first, then the field's ghosts), so we can gather the field
! input sub-vector and scatter the field output sub-vector without further
! communication (the halo exchange is done once by psb_spmm on the global desc).
!
module psb_d_nest_base_mat_mod
use psb_const_mod
use psb_error_mod
use psb_realloc_mod, only : psb_ensure_size
use psb_d_base_mat_mod, only : psb_d_base_sparse_mat
use psb_d_base_vect_mod, only : psb_d_base_vect_type
use psb_i_vect_mod, only : psb_i_vect_type
use psb_desc_mod, only : psb_desc_type
use psb_desc_nest_mod, only : psb_desc_nest_type
use psb_d_nest_mat_mod, only : psb_d_nest_sparse_mat
use psb_d_mat_mod, only : psb_dspmat_type
implicit none
! Per-field gather/scatter map into the global local vector.
! global_local_pos(1 : n_owned) -> the field's owned entries
! global_local_pos(n_owned+1 : size) -> the field's ghost (halo) entries
type :: psb_d_nest_field_map
integer(psb_ipk_) :: n_owned = 0
integer(psb_ipk_), allocatable :: global_local_pos(:)
! same positions as an encapsulated index vector, for the device-capable
! gather/scatter (gth/sct) used by vect_mv; pointer so that its target can
! be synced even when the operator dummy argument is intent(in)
type(psb_i_vect_type), pointer :: gather_pos => null()
end type psb_d_nest_field_map
type, extends(psb_d_base_sparse_mat) :: psb_d_nest_base_mat
integer(psb_ipk_) :: n_fields = 0
type(psb_d_nest_sparse_mat), pointer :: block_storage => null() ! blocks (not owned)
type(psb_desc_nest_type), pointer :: grid_desc => null() ! per-field descriptors (not owned)
type(psb_d_nest_field_map), allocatable :: field_map(:)
contains
procedure, pass(a) :: csmv => psb_d_nest_base_csmv
procedure, pass(a) :: get_nzeros => psb_d_nest_base_get_nzeros
procedure, nopass :: get_fmt => psb_d_nest_base_get_fmt
procedure, pass(a) :: free => psb_d_nest_base_free
! enable the stock PSBLAS preconditioners on the nested operator:
! get_diag is used by DIAG/JACOBI, csgetrow by BJAC (ILU factorizations
! go through the format-agnostic csget path)
procedure, pass(a) :: get_diag => psb_d_nest_base_get_diag
procedure, pass(a) :: csgetrow => psb_d_nest_base_csgetrow
! device-capable matvec on encapsulated vectors: gathers/scatters through
! the vectors' own gth/sct and runs each block through its vect_mv, so
! device block formats execute their device kernels
procedure, pass(a) :: vect_mv => psb_d_nest_base_vect_mv
! full base-class contract (delegating to the blocks):
procedure, pass(a) :: csmm => psb_d_nest_base_csmm
procedure, pass(a) :: cp_to_coo => psb_d_nest_base_cp_to_coo
procedure, pass(a) :: mv_to_coo => psb_d_nest_base_mv_to_coo
procedure, pass(a) :: rowsum => psb_d_nest_base_rowsum
procedure, pass(a) :: arwsum => psb_d_nest_base_arwsum
procedure, pass(a) :: colsum => psb_d_nest_base_colsum
procedure, pass(a) :: aclsum => psb_d_nest_base_aclsum
procedure, pass(a) :: maxval => psb_d_nest_base_maxval
procedure, pass(a) :: spnmi => psb_d_nest_base_csnmi
procedure, pass(a) :: spnm1 => psb_d_nest_base_csnm1
procedure, pass(a) :: scals => psb_d_nest_base_scals
procedure, pass(a) :: scalv => psb_d_nest_base_scal
procedure, pass(a) :: clone => psb_d_nest_base_clone
procedure, pass(a) :: mold => psb_d_nest_base_mold
procedure, pass(a) :: sizeof => psb_d_nest_base_sizeof
! NOT implemented on purpose (base error 700 is the intended behaviour):
! cp_from_coo / mv_from_coo (a nested operator cannot be built from a flat
! matrix without the field structure), csput (insertions go to the blocks
! before assembly), cssv/cssm (triangular solve is undefined for a block
! operator)
end type psb_d_nest_base_mat
private
public :: psb_d_nest_base_mat, psb_d_nest_base_setup, psb_d_nest_apply_block
! field-split interface (for the block preconditioner)
public :: psb_d_nest_get_n_fields, psb_d_nest_get_field_owned, &
& psb_d_nest_get_block, psb_d_nest_get_field_desc, &
& psb_d_nest_restrict_field, psb_d_nest_prolong_field
contains
function psb_d_nest_base_get_fmt() result(format_name)
character(len=5) :: format_name
format_name = 'NEST'
end function psb_d_nest_base_get_fmt
! free: the nested operator does NOT own block_storage / grid_desc (they are
! pointers into the caller), so we only detach them and release the field maps.
subroutine psb_d_nest_base_free(a)
class(psb_d_nest_base_mat), intent(inout) :: a
integer(psb_ipk_) :: i_field, local_info
if (allocated(a%field_map)) then
do i_field = 1, size(a%field_map)
if (associated(a%field_map(i_field)%gather_pos)) then
call a%field_map(i_field)%gather_pos%free(local_info)
deallocate(a%field_map(i_field)%gather_pos)
a%field_map(i_field)%gather_pos => null()
end if
end do
deallocate(a%field_map)
end if
a%block_storage => null()
a%grid_desc => null()
a%n_fields = 0
call a%set_null()
end subroutine psb_d_nest_base_free
function psb_d_nest_base_get_nzeros(a) result(total_nzeros)
class(psb_d_nest_base_mat), intent(in) :: a
integer(psb_ipk_) :: total_nzeros
integer(psb_ipk_) :: i_block_row, j_block_col
total_nzeros = 0
if (associated(a%block_storage)) then
do j_block_col = 1, a%block_storage%ncblocks
do i_block_row = 1, a%block_storage%nrblocks
if (a%block_storage%has_block(i_block_row, j_block_col)) &
& total_nzeros = total_nzeros + &
& a%block_storage%mats(i_block_row, j_block_col)%get_nzeros()
end do
end do
end if
end function psb_d_nest_base_get_nzeros
! get_diag: diagonal of the global operator. In the global-local layout the
! owned entries of field i occupy positions owned_offset+1..owned_offset+n_owned,
! and for owned indices the field-local column k maps to the same global-local
! position as row k, so the global diagonal is the concatenation of the
! diagonals of the diagonal blocks (i,i); absent blocks contribute zeros
! (e.g. the (2,2) block of a saddle-point operator).
subroutine psb_d_nest_base_get_diag(a, d, info)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(out) :: d(:)
integer(psb_ipk_), intent(out) :: info
real(psb_dpk_), allocatable :: block_diag(:)
integer(psb_ipk_) :: i_field, n_owned, owned_offset
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_get_diag'
if (.not. (associated(a%block_storage) .and. allocated(a%field_map))) then
info = psb_err_invalid_mat_state_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
if (size(d) < a%get_nrows()) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='d too small')
return
end if
d(1:a%get_nrows()) = dzero
owned_offset = 0
do i_field = 1, a%n_fields
n_owned = a%field_map(i_field)%n_owned
if (a%block_storage%has_block(i_field, i_field)) then
allocate(block_diag(n_owned), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
call a%block_storage%mats(i_field,i_field)%a%get_diag(block_diag, info)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block get_diag')
return
end if
d(owned_offset+1 : owned_offset+n_owned) = block_diag(1:n_owned)
deallocate(block_diag)
end if
owned_offset = owned_offset + n_owned
end do
end subroutine psb_d_nest_base_get_diag
! csgetrow: extract local rows imin..imax of the global operator as COO
! triplets, with columns in the global-local layout (the operator's column
! space). Each global-local row r belongs to one field i (row k within the
! field); its entries are the union over j of row k of block (i,j), with the
! block-local column c remapped through field_map(j)%global_local_pos(c).
! This is the format-agnostic access path used by the ILU factorizations of
! the BJAC preconditioner (via csget/csgetblk).
subroutine psb_d_nest_base_csgetrow(imin,imax,a,nz,ia,ja,val,info,&
& jmin,jmax,iren,append,nzin,rscale,cscale,chksz)
class(psb_d_nest_base_mat), intent(in) :: a
integer(psb_ipk_), intent(in) :: imin,imax
integer(psb_ipk_), intent(out) :: nz
integer(psb_ipk_), allocatable, intent(inout) :: ia(:), ja(:)
real(psb_dpk_), allocatable, intent(inout) :: val(:)
integer(psb_ipk_),intent(out) :: info
logical, intent(in), optional :: append
integer(psb_ipk_), intent(in), optional :: iren(:)
integer(psb_ipk_), intent(in), optional :: jmin,jmax, nzin
logical, intent(in), optional :: rscale,cscale,chksz
integer(psb_ipk_), allocatable :: block_row_ia(:), block_row_ja(:)
real(psb_dpk_), allocatable :: block_row_val(:)
integer(psb_ipk_) :: jmin_, jmax_, nzin_, out_pos
integer(psb_ipk_) :: r_row, i_field, j_field, k_in_field, owned_offset
integer(psb_ipk_) :: block_nz, t_entry, global_local_col
logical :: append_
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_csgetrow'
if (.not. (associated(a%block_storage) .and. allocated(a%field_map))) then
info = psb_err_invalid_mat_state_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
if (present(iren)) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='iren not supported'); return
end if
if (present(rscale)) then
if (rscale) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='rscale not supported'); return
end if
end if
if (present(cscale)) then
if (cscale) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='cscale not supported'); return
end if
end if
jmin_ = 1
jmax_ = a%get_ncols()
if (present(jmin)) jmin_ = jmin
if (present(jmax)) jmax_ = jmax
append_ = .false.
if (present(append)) append_ = append
nzin_ = 0
if (append_ .and. present(nzin)) nzin_ = nzin
nz = 0
out_pos = nzin_
do r_row = max(imin, 1), min(imax, a%get_nrows())
! locate the field owning global-local row r_row
owned_offset = 0
i_field = 0
do while (i_field < a%n_fields)
i_field = i_field + 1
if (r_row <= owned_offset + a%field_map(i_field)%n_owned) exit
owned_offset = owned_offset + a%field_map(i_field)%n_owned
end do
k_in_field = r_row - owned_offset
do j_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
call a%block_storage%mats(i_field,j_field)%a%csgetrow(k_in_field, k_in_field, &
& block_nz, block_row_ia, block_row_ja, block_row_val, info)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block csgetrow')
return
end if
do t_entry = 1, block_nz
global_local_col = a%field_map(j_field)%global_local_pos(block_row_ja(t_entry))
if ((global_local_col < jmin_) .or. (global_local_col > jmax_)) cycle
out_pos = out_pos + 1
call psb_ensure_size(out_pos, ia, info)
if (info == psb_success_) call psb_ensure_size(out_pos, ja, info)
if (info == psb_success_) call psb_ensure_size(out_pos, val, info)
if (info /= psb_success_) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
ia(out_pos) = r_row
ja(out_pos) = global_local_col
val(out_pos) = block_row_val(t_entry)
nz = nz + 1
end do
end do
end do
end subroutine psb_d_nest_base_csgetrow
! vect_mv: matvec on encapsulated vectors (the path taken by psb_spmm with
! psb_d_vect_type). Instead of falling back to the host-array csmv, it
! (1) gathers each column-field sub-vector through the vector's own gth with
! an encapsulated index vector (a device kernel on device vectors),
! (2) runs each block through its vect_mv (device formats execute their own
! device kernels), with per-field work vectors allocated with mold=x so
! they share the dynamic type of the incoming vectors,
! (3) scatters each row-field result back through the vector's own sct.
! Host/device traffic is limited to the compact field buffers; on plain host
! vectors this is exactly equivalent to the array csmv.
subroutine psb_d_nest_base_vect_mv(alpha, a, x, beta, y, info, trans)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(in) :: alpha, beta
class(psb_d_base_vect_type), intent(inout) :: x
class(psb_d_base_vect_type), intent(inout) :: y
integer(psb_ipk_), intent(out) :: info
character, optional, intent(in) :: trans
class(psb_d_base_vect_type), allocatable :: x_field_vec, y_field_vec
real(psb_dpk_), allocatable :: x_field_buf(:), y_field_buf(:)
real(psb_dpk_) :: block_beta
integer(psb_ipk_) :: i_field, j_field, n_owned, n_local, local_info
logical :: row_has_blocks
character :: trans_
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_vect_mv'
trans_ = 'N'
if (present(trans)) trans_ = trans
if (.not. (associated(a%block_storage) .and. allocated(a%field_map))) then
info = psb_err_invalid_mat_state_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
if (trans_ /= 'N' .and. trans_ /= 'n') then
! transposed product: fall back to host arrays (rare path)
block
real(psb_dpk_), allocatable :: x_host(:), y_host(:)
x_host = x%get_vect()
y_host = y%get_vect()
call psb_d_nest_base_csmv_t(alpha, a, x_host, beta, y_host, info)
call y%bld(y_host)
end block
return
end if
! work vectors share the dynamic type of the incoming vectors
allocate(x_field_vec, mold=x, stat=info)
if (info == 0) allocate(y_field_vec, mold=y, stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
do i_field = 1, a%n_fields
n_owned = a%field_map(i_field)%n_owned
call psb_ensure_size(n_owned, y_field_buf, info)
if (info /= psb_success_) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
row_has_blocks = .false.
block_beta = dzero
do j_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
! gather the column-field sub-vector (owned + ghosts) from x
n_local = size(a%field_map(j_field)%global_local_pos)
call psb_ensure_size(n_local, x_field_buf, info)
if (info /= psb_success_) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
call x%gth(ione, int(n_local, psb_mpk_), &
& a%field_map(j_field)%gather_pos%v, x_field_buf)
call x_field_vec%free(local_info)
call x_field_vec%bld(x_field_buf(1:n_local))
if (.not. row_has_blocks) then
! first block of this row field: (re)build the accumulator at the
! right size, zeroed
y_field_buf(1:n_owned) = dzero
call y_field_vec%free(local_info)
call y_field_vec%bld(y_field_buf(1:n_owned))
row_has_blocks = .true.
end if
! y_field = alpha * A(i,j) * x_field + block_beta * y_field
call a%block_storage%mats(i_field,j_field)%a%spmm(alpha, x_field_vec, &
& block_beta, y_field_vec, info)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block vect_mv')
return
end if
block_beta = done
end do
! scatter the row-field result into y (beta applied on the owned rows);
! a row field with no blocks still rescales its rows by beta
if (row_has_blocks) then
y_field_buf(1:n_owned) = y_field_vec%get_vect()
else
y_field_buf(1:n_owned) = dzero
end if
call y%sct(ione, int(n_owned, psb_mpk_), &
& a%field_map(i_field)%gather_pos%v, y_field_buf, beta)
end do
call x_field_vec%free(local_info)
call y_field_vec%free(local_info)
end subroutine psb_d_nest_base_vect_mv
! Build the per-field gather maps and set the local dimensions, from the nested
! grid descriptor (per-field distribution desc_grid%descs(1,field)) and the
! composed global descriptor desc_global (produced by psb_cd_nest_compose).
subroutine psb_d_nest_base_setup(nest_op, block_storage, desc_grid, desc_global, info)
type(psb_d_nest_base_mat), intent(inout) :: nest_op
type(psb_d_nest_sparse_mat), target, intent(in) :: block_storage
type(psb_desc_nest_type), target, intent(in) :: desc_grid
type(psb_desc_type), intent(in) :: desc_global
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_) :: n_fields, i_field, i_entry
integer(psb_ipk_) :: n_owned, n_local, n_ghost, owned_offset, local_pos
integer(psb_lpk_) :: global_idx
integer(psb_lpk_), allocatable :: field_global_offset(:)
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_base_setup'
if (desc_grid%nrblocks /= desc_grid%ncblocks) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='nested block structure must be square')
return
end if
n_fields = desc_grid%ncblocks
nest_op%n_fields = n_fields
nest_op%grid_desc => desc_grid
nest_op%block_storage => block_storage
! global field offsets (used to form ghost global indices)
allocate(field_global_offset(n_fields+1), nest_op%field_map(n_fields), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
field_global_offset(1) = 0
do i_field = 1, n_fields
field_global_offset(i_field+1) = field_global_offset(i_field) &
& + desc_grid%descs(1,i_field)%get_global_rows()
end do
owned_offset = 0 ! running owned-local offset in the global local vector
do i_field = 1, n_fields
n_owned = desc_grid%descs(1,i_field)%get_local_rows()
n_local = desc_grid%descs(1,i_field)%get_local_cols()
n_ghost = n_local - n_owned
nest_op%field_map(i_field)%n_owned = n_owned
allocate(nest_op%field_map(i_field)%global_local_pos(n_local), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
! owned entries: contiguous in the global local vector
do i_entry = 1, n_owned
nest_op%field_map(i_field)%global_local_pos(i_entry) = owned_offset + i_entry
end do
! ghost entries: locate the field's ghost global index in the global descriptor
do i_entry = 1, n_ghost
call desc_grid%descs(1,i_field)%l2g(n_owned + i_entry, global_idx, info)
if (info /= 0) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='l2g'); return
end if
call desc_global%g2l(field_global_offset(i_field) + global_idx, local_pos, info)
if (info /= 0) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='g2l'); return
end if
nest_op%field_map(i_field)%global_local_pos(n_owned + i_entry) = local_pos
end do
! encapsulated copy of the positions for the device-capable gth/sct
allocate(nest_op%field_map(i_field)%gather_pos, stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
call nest_op%field_map(i_field)%gather_pos%bld(nest_op%field_map(i_field)%global_local_pos)
owned_offset = owned_offset + n_owned
end do
call nest_op%set_nrows(desc_global%get_local_rows())
call nest_op%set_ncols(desc_global%get_local_cols())
call nest_op%set_asb()
end subroutine psb_d_nest_base_setup
! Local block matrix-vector product: y = alpha * A_nest * x + beta * y.
! x is in the global local layout (owned fields concatenated + global halo);
! y holds the owned entries (global local rows).
subroutine psb_d_nest_base_csmv(alpha, a, x, beta, y, info, trans)
real(psb_dpk_), intent(in) :: alpha, beta, x(:)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(inout) :: y(:)
integer(psb_ipk_), intent(out) :: info
character, optional, intent(in) :: trans
real(psb_dpk_), allocatable :: x_field(:), y_field(:)
integer(psb_ipk_) :: i_block_row, j_block_col, i_entry
integer(psb_ipk_) :: n_local_col_field, n_owned_row_field
character :: trans_op
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_base_csmv'
trans_op = 'N'
if (present(trans)) trans_op = trans
if (trans_op /= 'N' .and. trans_op /= 'n') then
! transposed product: the block structure of A^T is the transpose of the
! block grid, handled by the dedicated kernel below
call psb_d_nest_base_csmv_t(alpha, a, x, beta, y, info)
return
end if
if (.not. associated(a%block_storage)) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
! y <- beta * y
if (beta == dzero) then
y(:) = dzero
else if (beta /= done) then
y(:) = beta * y(:)
end if
do j_block_col = 1, a%n_fields
n_local_col_field = size(a%field_map(j_block_col)%global_local_pos)
allocate(x_field(n_local_col_field), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
! gather the column-field input sub-vector (owned + that field's ghosts)
do i_entry = 1, n_local_col_field
x_field(i_entry) = x(a%field_map(j_block_col)%global_local_pos(i_entry))
end do
do i_block_row = 1, a%n_fields
if (a%block_storage%has_block(i_block_row, j_block_col)) then
n_owned_row_field = a%field_map(i_block_row)%n_owned
allocate(y_field(n_owned_row_field), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
! current row-field output sub-vector (owned)
do i_entry = 1, n_owned_row_field
y_field(i_entry) = y(a%field_map(i_block_row)%global_local_pos(i_entry))
end do
! y_field <- alpha * A(i_block_row, j_block_col) * x_field + y_field
call a%block_storage%mats(i_block_row, j_block_col)%a%csmv( &
& alpha, x_field, done, y_field, info, trans_op)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block csmv')
return
end if
! scatter the row-field output sub-vector back into y
do i_entry = 1, n_owned_row_field
y(a%field_map(i_block_row)%global_local_pos(i_entry)) = y_field(i_entry)
end do
deallocate(y_field)
end if
end do
deallocate(x_field)
end do
end subroutine psb_d_nest_base_csmv
! Transposed matvec kernel: y = alpha * A^T * x + beta * y.
! The block structure of A^T is the transpose of the block grid:
! y(cols of field j) += alpha * sum_i A(i,j)^T * x(owned rows of field i).
! x is read on the owned rows of each row field; the result lands on ALL the
! local columns of each column field (owned + ghosts); the distributed caller
! (psb_spmm with trans='T') then accumulates the ghost contributions to their
! owners through the transposed halo exchange.
subroutine psb_d_nest_base_csmv_t(alpha, a, x, beta, y, info)
real(psb_dpk_), intent(in) :: alpha, beta, x(:)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(inout) :: y(:)
integer(psb_ipk_), intent(out) :: info
real(psb_dpk_), allocatable :: x_field(:), y_field(:)
integer(psb_ipk_) :: i_block_row, j_block_col, i_entry
integer(psb_ipk_) :: n_local_col_field, n_owned_row_field
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_base_csmv_t'
if (.not. associated(a%block_storage)) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
! y <- beta * y (on the whole column space)
if (beta == dzero) then
y(:) = dzero
else if (beta /= done) then
y(:) = beta * y(:)
end if
do j_block_col = 1, a%n_fields
n_local_col_field = size(a%field_map(j_block_col)%global_local_pos)
allocate(y_field(n_local_col_field), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
! current column-field output sub-vector (owned + ghosts)
do i_entry = 1, n_local_col_field
y_field(i_entry) = y(a%field_map(j_block_col)%global_local_pos(i_entry))
end do
do i_block_row = 1, a%n_fields
if (a%block_storage%has_block(i_block_row, j_block_col)) then
n_owned_row_field = a%field_map(i_block_row)%n_owned
allocate(x_field(n_owned_row_field), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
! gather the row-field input sub-vector (owned rows only)
do i_entry = 1, n_owned_row_field
x_field(i_entry) = x(a%field_map(i_block_row)%global_local_pos(i_entry))
end do
! y_field <- alpha * A(i,j)^T * x_field + y_field
call a%block_storage%mats(i_block_row, j_block_col)%a%csmv( &
& alpha, x_field, done, y_field, info, 'T')
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block csmv T')
return
end if
deallocate(x_field)
end if
end do
! scatter the column-field output sub-vector back into y
do i_entry = 1, n_local_col_field
y(a%field_map(j_block_col)%global_local_pos(i_entry)) = y_field(i_entry)
end do
deallocate(y_field)
end do
end subroutine psb_d_nest_base_csmv_t
! csmm: multi-RHS product, the 2D analogue of csmv (same gather/scatter
! per field, the block product is the block's own csmm)
subroutine psb_d_nest_base_csmm(alpha, a, x, beta, y, info, trans)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(in) :: alpha, beta, x(:,:)
real(psb_dpk_), intent(inout) :: y(:,:)
integer(psb_ipk_), intent(out) :: info
character, optional, intent(in) :: trans
real(psb_dpk_), allocatable :: x_field(:,:), y_field(:,:)
integer(psb_ipk_) :: i_block_row, j_block_col, i_entry
integer(psb_ipk_) :: n_local_col_field, n_owned_row_field, n_rhs
character :: trans_op
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_base_csmm'
trans_op = 'N'
if (present(trans)) trans_op = trans
if (trans_op /= 'N' .and. trans_op /= 'n') then
info = psb_err_transpose_not_n_unsupported_
call psb_errpush(info, name); return
end if
if (.not. associated(a%block_storage)) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
n_rhs = min(size(x,2), size(y,2))
if (beta == dzero) then
y(:,:) = dzero
else if (beta /= done) then
y(:,:) = beta * y(:,:)
end if
do j_block_col = 1, a%n_fields
n_local_col_field = size(a%field_map(j_block_col)%global_local_pos)
allocate(x_field(n_local_col_field, n_rhs), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
do i_entry = 1, n_local_col_field
x_field(i_entry, 1:n_rhs) = x(a%field_map(j_block_col)%global_local_pos(i_entry), 1:n_rhs)
end do
do i_block_row = 1, a%n_fields
if (a%block_storage%has_block(i_block_row, j_block_col)) then
n_owned_row_field = a%field_map(i_block_row)%n_owned
allocate(y_field(n_owned_row_field, n_rhs), stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, name); return
end if
do i_entry = 1, n_owned_row_field
y_field(i_entry, 1:n_rhs) = y(a%field_map(i_block_row)%global_local_pos(i_entry), 1:n_rhs)
end do
call a%block_storage%mats(i_block_row, j_block_col)%a%csmm( &
& alpha, x_field, done, y_field, info, trans_op)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block csmm')
return
end if
do i_entry = 1, n_owned_row_field
y(a%field_map(i_block_row)%global_local_pos(i_entry), 1:n_rhs) = y_field(i_entry, 1:n_rhs)
end do
deallocate(y_field)
end if
end do
deallocate(x_field)
end do
end subroutine psb_d_nest_base_csmm
! cp_to_coo: assemble all the blocks into a single local COO in the
! global-local layout (rows = concatenated owned rows, columns = the
! operator's column space). This is the core conversion hook: the generic
! base-class machinery builds cscnv, csclip, tril/triu, ... on top of it.
subroutine psb_d_nest_base_cp_to_coo(a, b, info)
use psb_d_base_mat_mod, only : psb_d_coo_sparse_mat
class(psb_d_nest_base_mat), intent(in) :: a
class(psb_d_coo_sparse_mat), intent(inout) :: b
integer(psb_ipk_), intent(out) :: info
type(psb_d_coo_sparse_mat) :: block_coo
integer(psb_ipk_) :: i_field, j_field, k_entry, n_entries, out_pos, owned_offset
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_cp_to_coo'
if (.not. (associated(a%block_storage) .and. allocated(a%field_map))) then
info = psb_err_invalid_mat_state_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
call b%allocate(a%get_nrows(), a%get_ncols(), a%get_nzeros())
out_pos = 0
owned_offset = 0
do i_field = 1, a%n_fields
do j_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
call a%block_storage%mats(i_field,j_field)%a%cp_to_coo(block_coo, info)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block cp_to_coo')
return
end if
n_entries = block_coo%get_nzeros()
do k_entry = 1, n_entries
b%ia(out_pos+k_entry) = owned_offset + block_coo%ia(k_entry)
b%ja(out_pos+k_entry) = a%field_map(j_field)%global_local_pos(block_coo%ja(k_entry))
b%val(out_pos+k_entry) = block_coo%val(k_entry)
end do
out_pos = out_pos + n_entries
call block_coo%free()
end do
owned_offset = owned_offset + a%field_map(i_field)%n_owned
end do
call b%set_nzeros(out_pos)
call b%set_dupl(psb_dupl_add_)
call b%fix(info)
if (info /= psb_success_) &
& call psb_errpush(psb_err_from_subroutine_, name, a_err='coo fix')
end subroutine psb_d_nest_base_cp_to_coo
! mv_to_coo: the adapter does not own the blocks, so "move" degenerates to
! copy + detach of the adapter
subroutine psb_d_nest_base_mv_to_coo(a, b, info)
use psb_d_base_mat_mod, only : psb_d_coo_sparse_mat
class(psb_d_nest_base_mat), intent(inout) :: a
class(psb_d_coo_sparse_mat), intent(inout) :: b
integer(psb_ipk_), intent(out) :: info
call a%cp_to_coo(b, info)
if (info == psb_success_) call a%free()
end subroutine psb_d_nest_base_mv_to_coo
! rowsum/arwsum: (absolute) row sums, accumulated across the blocks of each
! row field; d is in the global-local row layout
subroutine psb_d_nest_base_rowsum(d, a)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(out) :: d(:)
call psb_d_nest_base_sum_rows(d, a, absolute=.false.)
end subroutine psb_d_nest_base_rowsum
subroutine psb_d_nest_base_arwsum(d, a)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(out) :: d(:)
call psb_d_nest_base_sum_rows(d, a, absolute=.true.)
end subroutine psb_d_nest_base_arwsum
subroutine psb_d_nest_base_sum_rows(d, a, absolute)
real(psb_dpk_), intent(out) :: d(:)
class(psb_d_nest_base_mat), intent(in) :: a
logical, intent(in) :: absolute
real(psb_dpk_), allocatable :: block_sums(:)
integer(psb_ipk_) :: i_field, j_field, k_entry, n_owned, owned_offset
d(:) = dzero
if (.not. associated(a%block_storage)) return
owned_offset = 0
do i_field = 1, a%n_fields
n_owned = a%field_map(i_field)%n_owned
allocate(block_sums(n_owned))
do j_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
if (absolute) then
call a%block_storage%mats(i_field,j_field)%a%arwsum(block_sums)
else
call a%block_storage%mats(i_field,j_field)%a%rowsum(block_sums)
end if
do k_entry = 1, n_owned
d(owned_offset+k_entry) = d(owned_offset+k_entry) + block_sums(k_entry)
end do
end do
deallocate(block_sums)
owned_offset = owned_offset + n_owned
end do
end subroutine psb_d_nest_base_sum_rows
! colsum/aclsum: (absolute) column sums in the operator's column space,
! accumulated across the blocks of each column field
subroutine psb_d_nest_base_colsum(d, a)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(out) :: d(:)
call psb_d_nest_base_sum_cols(d, a, absolute=.false.)
end subroutine psb_d_nest_base_colsum
subroutine psb_d_nest_base_aclsum(d, a)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_), intent(out) :: d(:)
call psb_d_nest_base_sum_cols(d, a, absolute=.true.)
end subroutine psb_d_nest_base_aclsum
subroutine psb_d_nest_base_sum_cols(d, a, absolute)
real(psb_dpk_), intent(out) :: d(:)
class(psb_d_nest_base_mat), intent(in) :: a
logical, intent(in) :: absolute
real(psb_dpk_), allocatable :: field_sums(:), block_sums(:)
integer(psb_ipk_) :: i_field, j_field, k_entry, n_local
d(:) = dzero
if (.not. associated(a%block_storage)) return
do j_field = 1, a%n_fields
n_local = size(a%field_map(j_field)%global_local_pos)
allocate(field_sums(n_local), block_sums(n_local))
field_sums(:) = dzero
do i_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
if (absolute) then
call a%block_storage%mats(i_field,j_field)%a%aclsum(block_sums)
else
call a%block_storage%mats(i_field,j_field)%a%colsum(block_sums)
end if
field_sums(1:n_local) = field_sums(1:n_local) + block_sums(1:n_local)
end do
do k_entry = 1, n_local
d(a%field_map(j_field)%global_local_pos(k_entry)) = field_sums(k_entry)
end do
deallocate(field_sums, block_sums)
end do
end subroutine psb_d_nest_base_sum_cols
! maxval / infinity norm / 1-norm, by delegation/accumulation over blocks
function psb_d_nest_base_maxval(a) result(res)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_) :: res
integer(psb_ipk_) :: i_field, j_field
res = dzero
if (.not. associated(a%block_storage)) return
do j_field = 1, a%n_fields
do i_field = 1, a%n_fields
if (a%block_storage%has_block(i_field, j_field)) &
& res = max(res, a%block_storage%mats(i_field,j_field)%a%maxval())
end do
end do
end function psb_d_nest_base_maxval
function psb_d_nest_base_csnmi(a) result(res)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_) :: res
real(psb_dpk_), allocatable :: row_sums(:)
res = dzero
if (a%get_nrows() <= 0) return
allocate(row_sums(a%get_nrows()))
call psb_d_nest_base_sum_rows(row_sums, a, absolute=.true.)
res = maxval(row_sums)
end function psb_d_nest_base_csnmi
function psb_d_nest_base_csnm1(a) result(res)
class(psb_d_nest_base_mat), intent(in) :: a
real(psb_dpk_) :: res
real(psb_dpk_), allocatable :: col_sums(:)
res = dzero
if (a%get_ncols() <= 0) return
allocate(col_sums(a%get_ncols()))
call psb_d_nest_base_sum_cols(col_sums, a, absolute=.true.)
res = maxval(col_sums)
end function psb_d_nest_base_csnm1
! scals/scal: scaling acts on the underlying blocks (the operator is a view)
subroutine psb_d_nest_base_scals(d, a, info)
class(psb_d_nest_base_mat), intent(inout) :: a
real(psb_dpk_), intent(in) :: d
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_) :: i_field, j_field
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_scals'
if (.not. associated(a%block_storage)) then
info = psb_err_invalid_mat_state_; call psb_errpush(info, name); return
end if
do j_field = 1, a%n_fields
do i_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
call a%block_storage%mats(i_field,j_field)%a%scal(d, info)
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block scal'); return
end if
end do
end do
end subroutine psb_d_nest_base_scals
subroutine psb_d_nest_base_scal(d, a, info, side)
class(psb_d_nest_base_mat), intent(inout) :: a
real(psb_dpk_), intent(in) :: d(:)
integer(psb_ipk_), intent(out) :: info
character, intent(in), optional :: side
real(psb_dpk_), allocatable :: d_field(:)
integer(psb_ipk_) :: i_field, j_field, k_entry, n_owned, n_local, owned_offset
character :: side_
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_scal'
side_ = 'L'
if (present(side)) side_ = side
if (.not. associated(a%block_storage)) then
info = psb_err_invalid_mat_state_; call psb_errpush(info, name); return
end if
if (side_ == 'L' .or. side_ == 'l') then
! row scaling: each row field uses its owned slice of d
owned_offset = 0
do i_field = 1, a%n_fields
n_owned = a%field_map(i_field)%n_owned
do j_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
call a%block_storage%mats(i_field,j_field)%a%scal( &
& d(owned_offset+1:owned_offset+n_owned), info, side='L')
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block scal L'); return
end if
end do
owned_offset = owned_offset + n_owned
end do
else
! column scaling: each column field gathers its slice of d
do j_field = 1, a%n_fields
n_local = size(a%field_map(j_field)%global_local_pos)
allocate(d_field(n_local))
do k_entry = 1, n_local
d_field(k_entry) = d(a%field_map(j_field)%global_local_pos(k_entry))
end do
do i_field = 1, a%n_fields
if (.not. a%block_storage%has_block(i_field, j_field)) cycle
call a%block_storage%mats(i_field,j_field)%a%scal(d_field, info, side='R')
if (info /= psb_success_) then
call psb_errpush(psb_err_from_subroutine_, name, a_err='block scal R'); return
end if
end do
deallocate(d_field)
end do
end if
end subroutine psb_d_nest_base_scal
! clone: the adapter is a view, so the clone shares the blocks and the grid
! descriptor (pointers) while re-owning its private gather index vectors
subroutine psb_d_nest_base_clone(a, b, info)
class(psb_d_nest_base_mat), intent(inout) :: a
class(psb_d_base_sparse_mat), allocatable, intent(inout) :: b
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_) :: i_field
info = psb_success_
if (allocated(b)) deallocate(b)
allocate(b, source=a, stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, 'psb_d_nest_clone'); return
end if
select type (b_nest => b)
type is (psb_d_nest_base_mat)
if (allocated(b_nest%field_map)) then
do i_field = 1, size(b_nest%field_map)
! the sourced copy shares a's gather_pos targets: re-own fresh copies
b_nest%field_map(i_field)%gather_pos => null()
allocate(b_nest%field_map(i_field)%gather_pos, stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, 'psb_d_nest_clone'); return
end if
call b_nest%field_map(i_field)%gather_pos%bld( &
& b_nest%field_map(i_field)%global_local_pos)
end do
end if
end select
end subroutine psb_d_nest_base_clone
subroutine psb_d_nest_base_mold(a, b, info)
class(psb_d_nest_base_mat), intent(in) :: a
class(psb_d_base_sparse_mat), allocatable, intent(inout) :: b
integer(psb_ipk_), intent(out) :: info
info = psb_success_
if (allocated(b)) deallocate(b)
allocate(b, mold=a, stat=info)
if (info /= 0) then
info = psb_err_alloc_dealloc_; call psb_errpush(info, 'psb_d_nest_mold')
end if
end subroutine psb_d_nest_base_mold
! sizeof: blocks + gather maps (the adapter does not own the descriptors)
function psb_d_nest_base_sizeof(a) result(res)
class(psb_d_nest_base_mat), intent(in) :: a
integer(psb_epk_) :: res
integer(psb_ipk_) :: i_field
res = 8
if (associated(a%block_storage)) res = res + a%block_storage%sizeof()
if (allocated(a%field_map)) then
do i_field = 1, size(a%field_map)
if (allocated(a%field_map(i_field)%global_local_pos)) &
& res = res + psb_sizeof_ip * size(a%field_map(i_field)%global_local_pos)
end do
end if
end function psb_d_nest_base_sizeof
! Selective (regime 2) application of a SINGLE block:
! y_field = alpha * A(i_block_row, j_block_col) * x_field + beta * y_field
! x_field is the column-field local vector (owned + ghosts) ALREADY halo-exchanged
! by the caller; y_field is the row-field owned local vector. The caller chooses
! the exchange regime (the union halo, or just this block's halo), so this
! routine is purely local. It is FORMAT-AGNOSTIC: it dispatches to the block's
! own polymorphic csmv, so the block may be CSR, COO, ... independently of the
! other blocks. (The full-operator matvec, regime 1, is psb_d_nest_base_csmv.)
subroutine psb_d_nest_apply_block(nest_op, i_block_row, j_block_col, alpha, x_field, beta, y_field, info)
type(psb_d_nest_base_mat), intent(in) :: nest_op
integer(psb_ipk_), intent(in) :: i_block_row, j_block_col
real(psb_dpk_), intent(in) :: alpha, beta, x_field(:)
real(psb_dpk_), intent(inout) :: y_field(:)
integer(psb_ipk_), intent(out) :: info
character(len=24) :: name
info = psb_success_
name = 'psb_d_nest_apply_block'
if (.not. associated(nest_op%block_storage)) then
info = psb_err_invalid_input_
call psb_errpush(info, name, a_err='nested operator not set up')
return
end if
if (.not. nest_op%block_storage%has_block(i_block_row, j_block_col)) then
! absent block contributes zero: y_field <- beta * y_field
if (beta == dzero) then
y_field(:) = dzero
else if (beta /= done) then
y_field(:) = beta * y_field(:)
end if
return
end if
! polymorphic dispatch: the block applies its own format (CSR/COO/...)
call nest_op%block_storage%mats(i_block_row, j_block_col)%a%csmv( &
& alpha, x_field, beta, y_field, info)
if (info /= psb_success_) &
& call psb_errpush(psb_err_from_subroutine_, name, a_err='block csmv')
end subroutine psb_d_nest_apply_block
! ====================================================================
! Field-split interface (for the block preconditioner).
! Exposes the field structure so a fieldsplit/Schur preconditioner can:
! - know how many fields there are and their owned sizes;
! - get a block as a standard psb_dspmat_type (sub-preconditioner on A,
! Schur-complement matvecs with B / B^T);
! - get a field descriptor (run a field-level Krylov / halo exchange);
! - restrict the global vector to a field sub-vector and prolong it back.
! ====================================================================
function psb_d_nest_get_n_fields(nest_op) result(n_fields)
type(psb_d_nest_base_mat), intent(in) :: nest_op
integer(psb_ipk_) :: n_fields
n_fields = nest_op%n_fields
end function psb_d_nest_get_n_fields
function psb_d_nest_get_field_owned(nest_op, field) result(n_owned)
type(psb_d_nest_base_mat), intent(in) :: nest_op
integer(psb_ipk_), intent(in) :: field
integer(psb_ipk_) :: n_owned
n_owned = 0
if (allocated(nest_op%field_map) .and. field >= 1 .and. field <= nest_op%n_fields) &
& n_owned = nest_op%field_map(field)%n_owned
end function psb_d_nest_get_field_owned
! Pointer to block (i,j) as a standard psb_dspmat_type (null if absent).
function psb_d_nest_get_block(nest_op, i_block_row, j_block_col) result(block_ptr)
type(psb_d_nest_base_mat), target, intent(in) :: nest_op
integer(psb_ipk_), intent(in) :: i_block_row, j_block_col
type(psb_dspmat_type), pointer :: block_ptr
block_ptr => null()
if (associated(nest_op%block_storage)) then
if (nest_op%block_storage%has_block(i_block_row, j_block_col)) &
& block_ptr => nest_op%block_storage%mats(i_block_row, j_block_col)
end if
end function psb_d_nest_get_block
! Pointer to field k's descriptor (null if not set up).
function psb_d_nest_get_field_desc(nest_op, field) result(desc_ptr)
type(psb_d_nest_base_mat), target, intent(in) :: nest_op
integer(psb_ipk_), intent(in) :: field
type(psb_desc_type), pointer :: desc_ptr
desc_ptr => null()
if (associated(nest_op%grid_desc) .and. field >= 1 .and. field <= nest_op%n_fields) &
& desc_ptr => nest_op%grid_desc%descs(1, field)
end function psb_d_nest_get_field_desc
! Restrict: extract field k's OWNED sub-vector from the global local vector.
subroutine psb_d_nest_restrict_field(nest_op, field, x_global, x_field, info)
type(psb_d_nest_base_mat), intent(in) :: nest_op
integer(psb_ipk_), intent(in) :: field
real(psb_dpk_), intent(in) :: x_global(:)
real(psb_dpk_), intent(out) :: x_field(:)
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_) :: i_entry, n_owned
info = psb_success_
if (field < 1 .or. field > nest_op%n_fields) then
info = psb_err_invalid_input_; return
end if
n_owned = nest_op%field_map(field)%n_owned
do i_entry = 1, n_owned
x_field(i_entry) = x_global(nest_op%field_map(field)%global_local_pos(i_entry))
end do
end subroutine psb_d_nest_restrict_field
! Prolong: insert field k's OWNED sub-vector into the global local vector.
subroutine psb_d_nest_prolong_field(nest_op, field, x_field, x_global, info)
type(psb_d_nest_base_mat), intent(in) :: nest_op
integer(psb_ipk_), intent(in) :: field
real(psb_dpk_), intent(in) :: x_field(:)
real(psb_dpk_), intent(inout) :: x_global(:)
integer(psb_ipk_), intent(out) :: info
integer(psb_ipk_) :: i_entry, n_owned
info = psb_success_
if (field < 1 .or. field > nest_op%n_fields) then
info = psb_err_invalid_input_; return
end if
n_owned = nest_op%field_map(field)%n_owned
do i_entry = 1, n_owned
x_global(nest_op%field_map(field)%global_local_pos(i_entry)) = x_field(i_entry)
end do
end subroutine psb_d_nest_prolong_field
end module psb_d_nest_base_mat_mod