C $Header: /home/ubuntu/mnt/e9_copy/MITgcm_contrib/dgoldberg/streamice_oad_files/streamice_vel_solve_openad.F,v 1.5 2014/12/13 14:22:53 dgoldberg Exp $
C $Name:  $

#include "STREAMICE_OPTIONS.h"
#ifdef ALLOW_AUTODIFF
# include "AUTODIFF_OPTIONS.h"
#endif

C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|

CBOP
      SUBROUTINE STREAMICE_VEL_SOLVE_OPENAD ( myThid, maxNLIter, 
     &                                maxCGiter, myiter )
C     /============================================================\
C     | SUBROUTINE                                                 |
C     | o                                                          |
C     |============================================================|
C     |                                                            |
C     \============================================================/
      IMPLICIT NONE

C     === Global variables ===
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "STREAMICE.h"
#include "STREAMICE_CG.h"


#ifdef ALLOW_AUTODIFF_TAMC
# include "tamc.h"
#endif

C     !INPUT/OUTPUT ARGUMENTS
      INTEGER myThid
      INTEGER maxNLIter
      INTEGER maxCGIter
      INTEGER myIter

#ifdef ALLOW_STREAMICE

C     LOCAL VARIABLES

      INTEGER i, j, k, l, bi, bj, loopiter
      CHARACTER*(MAX_LEN_MBUF) msgBuf      

      INTEGER NL_iter 
      _RL err_last_change, cgtol
      LOGICAL CONVERGED

#ifdef ALLOW_OPENAD
      INTEGER ADJ_ITER
      LOGICAL ADJ_CONVERGED
#endif



#ifdef ALLOW_OPENAD
      isinloop0 =0
      isinloop1 =1
      isinloop2 =2
#endif


      IF (STREAMICE_ppm_driving_stress) THEN
       CALL STREAMICE_DRIVING_STRESS_PPM (myThid)
      ELSE
       CALL STREAMICE_DRIVING_STRESS (myThid)
      ENDIF

#ifdef STREAMICE_STRESS_BOUNDARY_CONTROL
      _EXCH_XY_RL( taudx_SI , myThid )
      _EXCH_XY_RL( taudy_SI , myThid )
      CALL STREAMICE_FORCED_BUTTRESS (myThid)
#endif

      CALL TIMER_START ('STREAMICE_VEL_SOLVE',myThid)

      cgtol = streamice_cg_tol
      nl_iter = 0
      CONVERGED = .false.
      err_last_change = 1 _d 1
      
      _EXCH_XY_RL( taudx_SI , myThid )
      _EXCH_XY_RL( taudy_SI , myThid )

       DO bj = myByLo(myThid), myByHi(myThid)
        DO bi = myBxLo(myThid), myBxHi(myThid)
         DO j=1-OLy,sNy+OLy
          DO i=1-OLx,sNx+OLx
!           U_streamice (i,j,bi,bj)=U_streamice (i,j,bi,bj)+
!     &       0.0*u_new_SI (i,j,bi,bj)
!           V_streamice (i,j,bi,bj)=V_streamice (i,j,bi,bj)+
!     &       0.0*v_new_SI (i,j,bi,bj)
           U_streamice (i,j,bi,bj)=0.0*U_streamice (i,j,bi,bj)+
     &       0.0*u_new_SI (i,j,bi,bj)
           V_streamice (i,j,bi,bj)=0.0*V_streamice (i,j,bi,bj)+
     &       0.0*v_new_SI (i,j,bi,bj)
          ENDDO
         ENDDO
        ENDDO
       ENDDO
#ifndef ALLOW_OPENAD
      CALL STREAMICE_VEL_PHISTAGE ( 
     I                   myThid, 
     I                   maxNLIter, 
     I                   maxCGiter, 
     O                   cgtol, 
     O                   nL_iter,
     O                   CONVERGED,
     O                   err_last_change,
     I                   isinloop0)
#else
      CALL STREAMICE_VEL_PHISTAGE ( 
     I                   myThid, 
     I                   maxNLIter, 
     I                   maxCGiter, 
     O                   cgtol, 
     O                   nL_iter,
     O                   adj_iter,
     O                   CONVERGED,
     O                   ADJ_CONVERGED,
     O                   err_last_change,
     I                   isinloop0)
#endif

      DO loopiter=1,maxNLIter

C     To avoid using "exit", loop goes through all iterations
C       but after convergence loop does nothing

!        IF (.not.CONVERGED) THEN

#ifndef ALLOW_OPENAD
      CALL STREAMICE_VEL_PHISTAGE ( 
     I                   myThid, 
     I                   maxNLIter, 
     I                   maxCGiter, 
     O                   cgtol, 
     O                   nL_iter,
     O                   CONVERGED,
     O                   err_last_change,
     I                   isinloop1)
#else
      CALL STREAMICE_VEL_PHISTAGE ( 
     I                   myThid, 
     I                   maxNLIter, 
     I                   maxCGiter, 
     O                   cgtol, 
     O                   nL_iter,
     O                   adj_iter,
     O                   CONVERGED,
     O                   ADJ_CONVERGED,
     O                   err_last_change,
     I                   isinloop1)
#endif



      ENDDO

#ifndef ALLOW_OPENAD
      CALL STREAMICE_VEL_PHISTAGE ( 
     I                   myThid, 
     I                   maxNLIter, 
     I                   maxCGiter, 
     O                   cgtol, 
     O                   nL_iter,
     O                   CONVERGED,
     O                   err_last_change,
     I                   isinloop2)
#else
      CALL STREAMICE_VEL_PHISTAGE ( 
     I                   myThid, 
     I                   maxNLIter, 
     I                   maxCGiter, 
     O                   cgtol, 
     O                   nL_iter,
     O                   adj_iter,
     O                   CONVERGED,
     O                   ADJ_CONVERGED,
     O                   err_last_change,
     I                   isinloop2)
#endif



C END NL ITER. LOOP
C-------------------------------------------------------------------

      if (nl_iter .lt. streamice_max_nl_iter) then
       WRITE(msgBuf,'(A,I5,A)') 'VELOCITY SOLVE CONVERGED, ',
     &         nl_iter, ' iterations'
       CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
     &                     SQUEEZE_RIGHT , 1)
      else
       WRITE(msgBuf,'(A,I5,A)') 'VELOCITY SOLVE NOT CONVERGED IN ',
     &         nl_iter, ' iterations'
       CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,
     &                     SQUEEZE_RIGHT , 1)
      endif

      _EXCH_XY_RL(U_streamice, myThid)
      _EXCH_XY_RL(V_streamice, myThid)

      CALL TIMER_STOP ('STREAMICE_VEL_SOLVE',myThid)

#endif
      RETURN
      END