You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
427 lines
15 KiB
Fortran
427 lines
15 KiB
Fortran
!!$
|
|
!!$ Parallel Sparse BLAS v2.0
|
|
!!$ (C) Copyright 2006 Salvatore Filippone University of Rome Tor Vergata
|
|
!!$ Alfredo Buttari University of Rome Tor Vergata
|
|
!!$
|
|
!!$ 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 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.
|
|
!!$
|
|
!!$
|
|
!!$ CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
|
|
!!$ C C
|
|
!!$ C References: C
|
|
!!$ C [1] Duff, I., Marrone, M., Radicati, G., and Vittoli, C. C
|
|
!!$ C Level 3 basic linear algebra subprograms for sparse C
|
|
!!$ C matrices: a user level interface C
|
|
!!$ C ACM Trans. Math. Softw., 23(3), 379-401, 1997. C
|
|
!!$ C C
|
|
!!$ C C
|
|
!!$ C [2] S. Filippone, M. Colajanni C
|
|
!!$ C PSBLAS: A library for parallel linear algebra C
|
|
!!$ C computation on sparse matrices C
|
|
!!$ C ACM Trans. on Math. Softw., 26(4), 527-550, Dec. 2000. C
|
|
!!$ C C
|
|
!!$ C [3] M. Arioli, I. Duff, M. Ruiz C
|
|
!!$ C Stopping criteria for iterative solvers C
|
|
!!$ C SIAM J. Matrix Anal. Appl., Vol. 13, pp. 138-144, 1992 C
|
|
!!$ C C
|
|
!!$ C C
|
|
!!$ C [4] R. Barrett et al C
|
|
!!$ C Templates for the solution of linear systems C
|
|
!!$ C SIAM, 1993 C
|
|
!!$ C C
|
|
!!$ C C
|
|
!!$ C [5] G. Sleijpen, D. Fokkema C
|
|
!!$ C BICGSTAB(L) for linear equations involving unsymmetric C
|
|
!!$ C matrices with complex spectrum C
|
|
!!$ C Electronic Trans. on Numer. Analysis, Vol. 1, pp. 11-32, C
|
|
!!$ C Sep. 1993 C
|
|
!!$ C C
|
|
!!$ C C
|
|
!!$ CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
|
|
! File: psb_dcgstabl.f90
|
|
!
|
|
! Subroutine: psb_dcgstabl
|
|
!
|
|
! Arguments:
|
|
! a - type(<psb_dspmat_type>). The sparse matrix containing A.
|
|
! prec - type(<psb_prec_type>). The data structure containing the preconditioner.
|
|
! b - real,dimension(:). The right hand side.
|
|
! x - real,dimension(:). The vector of unknowns.
|
|
! eps - real. The error tolerance.
|
|
! desc_a - type(<psb_desc_type>). The communication descriptor.
|
|
! info - integer. Return code
|
|
! itmax - integer(optional). The maximum number of iterations.
|
|
! iter - integer(optional). The number of iterations performed.
|
|
! err - real(optional). The error on return.
|
|
! itrace - integer(optional). The unit to write messages onto.
|
|
! istop - integer(optional). The stopping criterium.
|
|
!
|
|
Subroutine psb_dcgstabl(a,prec,b,x,eps,desc_a,info,&
|
|
&itmax,iter,err,itrace,irst,istop)
|
|
use psb_base_mod
|
|
use psb_prec_mod
|
|
implicit none
|
|
|
|
!!$ parameters
|
|
Type(psb_dspmat_type), Intent(in) :: a
|
|
Type(psb_dprec_type), Intent(in) :: prec
|
|
Type(psb_desc_type), Intent(in) :: desc_a
|
|
Real(Kind(1.d0)), Intent(in) :: b(:)
|
|
Real(Kind(1.d0)), Intent(inout) :: x(:)
|
|
Real(Kind(1.d0)), Intent(in) :: eps
|
|
integer, intent(out) :: info
|
|
Integer, Optional, Intent(in) :: itmax, itrace, irst,istop
|
|
Integer, Optional, Intent(out) :: iter
|
|
Real(Kind(1.d0)), Optional, Intent(out) :: err
|
|
!!$ local data
|
|
Real(Kind(1.d0)), allocatable, target :: aux(:),wwrk(:,:),uh(:,:), rh(:,:)
|
|
Real(Kind(1.d0)), Pointer :: ww(:), q(:), r(:), rt0(:), p(:), v(:), &
|
|
& s(:), t(:), z(:), f(:), gamma(:), gamma1(:), gamma2(:), taum(:,:), sigma(:)
|
|
|
|
Real(Kind(1.d0)) :: rerr
|
|
Integer :: litmax, naux, m, mglob, it, itrace_,&
|
|
& np,me, n_row, n_col, nl, err_act
|
|
Logical, Parameter :: exchange=.True., noexchange=.False.
|
|
Integer, Parameter :: irmax = 8
|
|
Integer :: itx, i, isvch, ich, ictxt,istop_,j, int_err(5)
|
|
Logical, Parameter :: debug = .False.
|
|
Real(Kind(1.d0)) :: alpha, beta, rho, rho_old, rni, xni, bni, ani,bn2,&
|
|
& omega, tau
|
|
character(len=20) :: name
|
|
|
|
info = 0
|
|
name = 'psb_dcgstabl'
|
|
call psb_erractionsave(err_act)
|
|
|
|
If (debug) Write(0,*) 'entering psb_dbicgstabl'
|
|
ictxt = psb_cd_get_context(desc_a)
|
|
Call psb_info(ictxt, me, np)
|
|
|
|
If (debug) Write(0,*) 'psb_dbicgstabl: from gridinfo',np,me
|
|
|
|
mglob = psb_cd_get_global_rows(desc_a)
|
|
n_row = psb_cd_get_local_rows(desc_a)
|
|
n_col = psb_cd_get_local_cols(desc_a)
|
|
|
|
if (present(istop)) then
|
|
istop_ = istop
|
|
else
|
|
istop_ = 1
|
|
endif
|
|
!
|
|
! ISTOP_ = 1: Normwise backward error, infinity norm
|
|
! ISTOP_ = 2: ||r||/||b|| norm 2
|
|
!
|
|
|
|
if ((istop_ < 1 ).or.(istop_ > 2 ) ) then
|
|
write(0,*) 'psb_bicgstabl: invalid istop',istop_
|
|
info=5001
|
|
int_err=istop_
|
|
err=info
|
|
call psb_errpush(info,name,i_err=int_err)
|
|
goto 9999
|
|
endif
|
|
|
|
If (Present(itmax)) Then
|
|
litmax = itmax
|
|
Else
|
|
litmax = 1000
|
|
Endif
|
|
|
|
If (Present(itrace)) Then
|
|
itrace_ = itrace
|
|
Else
|
|
itrace_ = 0
|
|
End If
|
|
|
|
If (Present(irst)) Then
|
|
nl = irst
|
|
If (debug) Write(0,*) 'present: irst: ',irst,nl
|
|
Else
|
|
nl = 1
|
|
If (debug) Write(0,*) 'not present: irst: ',irst,nl
|
|
Endif
|
|
if (nl <=0 ) then
|
|
write(0,*) 'psb_bicgstabl: invalid irst ',nl
|
|
info=5001
|
|
int_err(1)=nl
|
|
err=info
|
|
call psb_errpush(info,name,i_err=int_err)
|
|
goto 9999
|
|
endif
|
|
|
|
call psb_chkvect(mglob,1,size(x,1),1,1,desc_a,info)
|
|
if(info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_chkvect on X')
|
|
goto 9999
|
|
end if
|
|
call psb_chkvect(mglob,1,size(b,1),1,1,desc_a,info)
|
|
if(info /= 0) then
|
|
info=4010
|
|
call psb_errpush(info,name,a_err='psb_chkvect on B')
|
|
goto 9999
|
|
end if
|
|
|
|
naux=4*n_col
|
|
Allocate(aux(naux),gamma(0:nl),gamma1(nl),&
|
|
&gamma2(nl),taum(nl,nl),sigma(nl), stat=info)
|
|
|
|
If (info.Ne.0) Then
|
|
info=4000
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
End If
|
|
if (info == 0) Call psb_geall(wwrk,desc_a,info,n=10)
|
|
if (info == 0) Call psb_geall(uh,desc_a,info,n=nl+1)
|
|
if (info == 0) Call psb_geall(rh,desc_a,info,n=nl+1)
|
|
if (info == 0) Call psb_geasb(wwrk,desc_a,info)
|
|
if (info == 0) Call psb_geasb(uh,desc_a,info)
|
|
if (info == 0) Call psb_geasb(rh,desc_a,info)
|
|
if (info.ne.0) Then
|
|
info=4011
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
End If
|
|
|
|
q => wwrk(:,1)
|
|
r => wwrk(:,2)
|
|
p => wwrk(:,3)
|
|
v => wwrk(:,4)
|
|
f => wwrk(:,5)
|
|
s => wwrk(:,6)
|
|
t => wwrk(:,7)
|
|
z => wwrk(:,8)
|
|
ww => wwrk(:,9)
|
|
rt0 => wwrk(:,10)
|
|
|
|
! Ensure global coherence for convergence checks.
|
|
call psb_set_coher(ictxt,isvch)
|
|
|
|
if (istop_ == 1) then
|
|
ani = psb_spnrmi(a,desc_a,info)
|
|
bni = psb_geamax(b,desc_a,info)
|
|
else if (istop_ == 2) then
|
|
bn2 = psb_genrm2(b,desc_a,info)
|
|
endif
|
|
if (info.ne.0) Then
|
|
info=4011
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
End If
|
|
|
|
itx = 0
|
|
restart: Do
|
|
!!$
|
|
!!$ r0 = b-ax0
|
|
!!$
|
|
If (debug) Write(0,*) 'restart: ',itx,it
|
|
If (itx.Ge.litmax) Exit restart
|
|
it = 0
|
|
Call psb_geaxpby(done,b,dzero,r,desc_a,info)
|
|
Call psb_spmm(-done,a,x,done,r,desc_a,info,work=aux)
|
|
|
|
call psb_precaply(prec,r,desc_a,info)
|
|
|
|
Call psb_geaxpby(done,r,dzero,rt0,desc_a,info)
|
|
Call psb_geaxpby(done,r,dzero,rh(:,0),desc_a,info)
|
|
Call psb_geaxpby(dzero,r,dzero,uh(:,0),desc_a,info)
|
|
if (info.ne.0) Then
|
|
info=4011
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
End If
|
|
|
|
rho = done
|
|
alpha = dzero
|
|
omega = done
|
|
|
|
If (debug) Write(0,*) 'on entry to amax: b: ',Size(b)
|
|
|
|
if (istop_ == 1) then
|
|
rni = psb_geamax(r,desc_a,info)
|
|
xni = psb_geamax(x,desc_a,info)
|
|
rerr = rni/(ani*xni+bni)
|
|
else if (istop_ == 2) then
|
|
rni = psb_genrm2(r,desc_a,info)
|
|
rerr = rni/bn2
|
|
endif
|
|
if (info.ne.0) Then
|
|
info=4011
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
End If
|
|
|
|
If (rerr<=eps) Then
|
|
Exit restart
|
|
End If
|
|
If (itrace_ > 0) then
|
|
if ((mod(itx,itrace_)==0).and.(me == 0))&
|
|
& write(*,'(a,i4,3(2x,es10.4))') 'bicgstab(l): ',itx,rerr
|
|
end If
|
|
|
|
iteration: Do
|
|
it = it + nl
|
|
itx = itx + nl
|
|
rho = -omega*rho
|
|
If (debug) Write(0,*) 'iteration: ',itx, rho,rh(1,0)
|
|
|
|
Do j = 0, nl -1
|
|
If (debug) Write(0,*) 'bicg part: ',j, nl
|
|
rho_old = rho
|
|
rho = psb_gedot(rh(:,j),rt0,desc_a,info)
|
|
If (rho==dzero) Then
|
|
If (debug) Write(0,*) 'bi-cgstab iteration breakdown r',rho
|
|
Exit iteration
|
|
Endif
|
|
beta = alpha*rho/rho_old
|
|
If (debug) Write(0,*) 'bicg part: ',alpha,beta,rho,rho_old
|
|
rho_old = rho
|
|
Call psb_geaxpby(done,rh(:,0:j),-beta,uh(:,0:j),desc_a,info)
|
|
If (debug) Write(0,*) 'bicg part: ',rh(1,0),beta
|
|
Call psb_spmm(done,a,uh(:,j),dzero,uh(:,j+1),desc_a,info,work=aux)
|
|
|
|
call psb_precaply(prec,uh(:,j+1),desc_a,info)
|
|
|
|
gamma(j) = psb_gedot(uh(:,j+1),rt0,desc_a,info)
|
|
If (gamma(j)==dzero) Then
|
|
If (debug) Write(0,*) 'bi-cgstab iteration breakdown s2',gamma(j)
|
|
Exit iteration
|
|
Endif
|
|
alpha = rho/gamma(j)
|
|
If (debug) Write(0,*) 'bicg part: alpha=r/g ',alpha,rho,gamma(j)
|
|
|
|
Call psb_geaxpby(-alpha,uh(:,1:j+1),done,rh(:,0:j),desc_a,info)
|
|
Call psb_geaxpby(alpha,uh(:,0),done,x,desc_a,info)
|
|
Call psb_spmm(done,a,rh(:,j),dzero,rh(:,j+1),desc_a,info,work=aux)
|
|
|
|
call psb_precaply(prec,rh(:,j+1),desc_a,info)
|
|
|
|
Enddo
|
|
|
|
Do j=1, nl
|
|
If (debug) Write(0,*) 'mod g-s part: ',j, nl,rh(1,0)
|
|
Do i=1, j-1
|
|
taum(i,j) = psb_gedot(rh(:,i),rh(:,j),desc_a,info)
|
|
taum(i,j) = taum(i,j)/sigma(i)
|
|
Call psb_geaxpby(-taum(i,j),rh(:,i),done,rh(:,j),desc_a,info)
|
|
Enddo
|
|
If (debug) Write(0,*) 'mod g-s part: dot prod '
|
|
sigma(j) = psb_gedot(rh(:,j),rh(:,j),desc_a,info)
|
|
gamma1(j) = psb_gedot(rh(:,0),rh(:,j),desc_a,info)
|
|
If (debug) Write(0,*) 'mod g-s part: gamma1 ', &
|
|
&gamma1(j), sigma(j)
|
|
gamma1(j) = gamma1(j)/sigma(j)
|
|
Enddo
|
|
|
|
gamma(nl) = gamma1(nl)
|
|
omega = gamma(nl)
|
|
|
|
Do j=nl-1,1,-1
|
|
gamma(j) = gamma1(j)
|
|
Do i=j+1,nl
|
|
gamma(j) = gamma(j) - taum(j,i) * gamma(i)
|
|
Enddo
|
|
Enddo
|
|
If (debug) Write(0,*) 'first solve: ', gamma(:)
|
|
|
|
Do j=1,nl-1
|
|
gamma2(j) = gamma(j+1)
|
|
Do i=j+1,nl-1
|
|
gamma2(j) = gamma2(j) + taum(j,i) * gamma(i+1)
|
|
Enddo
|
|
Enddo
|
|
If (debug) Write(0,*) 'second solve: ', gamma(:)
|
|
|
|
Call psb_geaxpby(gamma(1),rh(:,0),done,x,desc_a,info)
|
|
Call psb_geaxpby(-gamma1(nl),rh(:,nl),done,rh(:,0),desc_a,info)
|
|
Call psb_geaxpby(-gamma(nl),uh(:,nl),done,uh(:,0),desc_a,info)
|
|
|
|
Do j=1, nl-1
|
|
Call psb_geaxpby(-gamma(j),uh(:,j),done,uh(:,0),desc_a,info)
|
|
Call psb_geaxpby(gamma2(j),rh(:,j),done,x,desc_a,info)
|
|
Call psb_geaxpby(-gamma1(j),rh(:,j),done,rh(:,0),desc_a,info)
|
|
Enddo
|
|
|
|
if (istop_ == 1) then
|
|
rni = psb_geamax(rh(:,0),desc_a,info)
|
|
xni = psb_geamax(x,desc_a,info)
|
|
rerr = rni/(ani*xni+bni)
|
|
else if (istop_ == 2) then
|
|
rni = psb_genrm2(rh(:,0),desc_a,info)
|
|
rerr = rni/bn2
|
|
endif
|
|
|
|
If (rerr<=eps) Then
|
|
Exit restart
|
|
End If
|
|
If (itx.Ge.litmax) Exit restart
|
|
|
|
If (itrace_ > 0) then
|
|
if ((mod(itx,itrace_)==0).and.(me == 0))&
|
|
& write(*,'(a,i4,3(2x,es10.4))') 'bicgstab(l): ',itx,rerr
|
|
end If
|
|
|
|
End Do iteration
|
|
End Do restart
|
|
|
|
If (itrace_ > 0) then
|
|
if (me == 0) write(*,'(a,i4,3(2x,es10.4))') 'bicgstab(l): ',itx,rerr
|
|
end If
|
|
If (Present(err)) err=rerr
|
|
If (Present(iter)) iter = itx
|
|
If (rerr>eps) Then
|
|
Write(0,*) 'bi-cgstabl failed to converge to ',eps,&
|
|
& ' in ',itx,' iterations '
|
|
End If
|
|
|
|
Deallocate(aux)
|
|
Call psb_gefree(wwrk,desc_a,info)
|
|
Call psb_gefree(uh,desc_a,info)
|
|
Call psb_gefree(rh,desc_a,info)
|
|
|
|
! restore external global coherence behaviour
|
|
call psb_restore_coher(ictxt,isvch)
|
|
|
|
if(info/=0) then
|
|
call psb_errpush(info,name)
|
|
goto 9999
|
|
end if
|
|
|
|
call psb_erractionrestore(err_act)
|
|
return
|
|
|
|
9999 continue
|
|
call psb_erractionrestore(err_act)
|
|
if (err_act.eq.psb_act_abort_) then
|
|
call psb_error()
|
|
return
|
|
end if
|
|
return
|
|
|
|
End Subroutine psb_dcgstabl
|
|
|
|
|