/*
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *<LicenseText>
 *
 * CitcomS by Louis Moresi, Shijie Zhong, Lijie Han, Eh Tan,
 * Clint Conrad, Michael Gurnis, and Eun-seo Choi.
 * Copyright (C) 1994-2005, California Institute of Technology.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *</LicenseText>
 *
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */
/* Routines here are for intel paragon with MPI */

#include <mpi.h>
#include <math.h>

#include "element_definitions.h"
#include "global_defs.h"
#include "sphere_communication.h"

#include "parallel_related.h"


static void set_horizontal_communicator(struct All_variables*);
static void set_vertical_communicator(struct All_variables*);

static void exchange_node_d(struct All_variables *, double*, int);
static void exchange_node_f(struct All_variables *, float*, int);


/* ============================================ */
/* ============================================ */

void full_parallel_processor_setup(struct All_variables *E)
  {

  int i,j,k,m,me,temp,pid_surf;
  int cap_id_surf;
  int surf_proc_per_cap, proc_per_cap, total_proc;

  me = E->parallel.me;

  if ( E->parallel.nprocx != E->parallel.nprocy ) {
    if (E->parallel.me==0) fprintf(stderr,"!!!! nprocx must equal to nprocy \n");
    parallel_process_termination();
  }

  surf_proc_per_cap = E->parallel.nprocx * E->parallel.nprocy;
  proc_per_cap = surf_proc_per_cap * E->parallel.nprocz;
  total_proc = E->sphere.caps * proc_per_cap;
  E->parallel.total_surf_proc = E->sphere.caps * surf_proc_per_cap;

  if ( total_proc != E->parallel.nproc ) {
    if (E->parallel.me==0) fprintf(stderr,"!!!! # of requested CPU is incorrect (expected: %i got: %i)\n",
				   total_proc, E->parallel.nproc);
    parallel_process_termination();
    }

  /* determine the location of processors in each cap */
  cap_id_surf = me / proc_per_cap;

 /* z-direction first*/
  E->parallel.me_loc[3] = (me - cap_id_surf*proc_per_cap) % E->parallel.nprocz;

 /* x-direction then*/
  E->parallel.me_loc[1] = ((me - cap_id_surf*proc_per_cap - E->parallel.me_loc[3])/E->parallel.nprocz) % E->parallel.nprocx;

 /* y-direction then*/
  E->parallel.me_loc[2] = ((((me - cap_id_surf*proc_per_cap - E->parallel.me_loc[3])/E->parallel.nprocz) - E->parallel.me_loc[1])/E->parallel.nprocx) % E->parallel.nprocy;


/*
the numbering of proc in each caps is as so (example for an xyz = 2x2x2 box):
NOTE: This is different (in a way) than the numbering of the nodes:
the nodeal number has the first oordinate as theta, which goes N-S and
the second oordinate as fi, which goes E-W. Here we use R-L as the first
oordinate and F-B
 0 = lower  left front corner=[000]  4 = lower  left back corner=[010]
 1 = upper  left front corner=[001]  5 = upper  left back corner=[011]
 2 = lower right front corner=[100]  6 = lower right back corner=[110]
 3 = upper right front corner=[101]  7 = upper right back corner=[111]
[xyz] is x=E->parallel.me_loc[1],y=E->parallel.me_loc[2],z=E->parallel.me_loc[3]
*/

  /* determine cap id for each cap in a given processor  */
  pid_surf = me/proc_per_cap; /* cap number (0~11) */
  i = cases[1]; /* 1 for more than 12 processors */

    temp = pid_surf; /* cap number (out of 12) */
    E->sphere.capid[1] = incases1[i].links[temp]; /* id (1~12) of the current cap */

  /* determine which caps are linked with each of 12 caps  */
  /* if the 12 caps are broken, set these up instead */
  if (surf_proc_per_cap > 1) {
     E->sphere.max_connections = 8;
  }

  /* steup location-to-processor map */
  E->parallel.loc2proc_map = (int ****) malloc(E->sphere.caps*sizeof(int ***));
  for (m=0;m<E->sphere.caps;m++)  {
    E->parallel.loc2proc_map[m] = (int ***) malloc(E->parallel.nprocx*sizeof(int **));
    for (i=0;i<E->parallel.nprocx;i++) {
      E->parallel.loc2proc_map[m][i] = (int **) malloc(E->parallel.nprocy*sizeof(int *));
      for (j=0;j<E->parallel.nprocy;j++)
	E->parallel.loc2proc_map[m][i][j] = (int *) malloc(E->parallel.nprocz*sizeof(int));
    }
  }

  for (m=0;m<E->sphere.caps;m++)
    for (i=0;i<E->parallel.nprocx;i++)
      for (j=0;j<E->parallel.nprocy;j++)
	for (k=0;k<E->parallel.nprocz;k++) {
	    E->parallel.loc2proc_map[m][i][j][k] = m*proc_per_cap
	      + j*E->parallel.nprocx*E->parallel.nprocz
	      + i*E->parallel.nprocz + k;
	}

  if (E->control.verbose) {
    fprintf(E->fp_out,"me=%d loc1=%d loc2=%d loc3=%d\n",me,E->parallel.me_loc[1],E->parallel.me_loc[2],E->parallel.me_loc[3]);
      fprintf(E->fp_out,"capid[1]=%d \n",E->sphere.capid[1]);
    for (m=0;m<E->sphere.caps;m++)
      for (j=0;j<E->parallel.nprocy;j++)
	for (i=0;i<E->parallel.nprocx;i++)
	  for (k=0;k<E->parallel.nprocz;k++)
	    fprintf(E->fp_out,"loc2proc_map[cap=%d][x=%d][y=%d][z=%d] = %d\n",
		    m,i,j,k,E->parallel.loc2proc_map[m][i][j][k]);

    fflush(E->fp_out);
  }

  set_vertical_communicator(E);
  set_horizontal_communicator(E);

  E->exchange_node_d = exchange_node_d;
  E->exchange_node_f = exchange_node_f;

  return;
  }



static void set_horizontal_communicator(struct All_variables *E)
{
  MPI_Group world_g, horizon_g;
  int i,j,k,m,n;
  int *processors;

  processors = (int *) malloc((E->parallel.total_surf_proc+1)*sizeof(int));

  k = E->parallel.me_loc[3];
  n = 0;
  for (m=0;m<E->sphere.caps;m++)
    for (i=0;i<E->parallel.nprocx;i++)
      for (j=0;j<E->parallel.nprocy;j++) {
	processors[n] = E->parallel.loc2proc_map[m][i][j][k];
	n++;
      }

  MPI_Comm_group(E->parallel.world, &world_g);
  MPI_Group_incl(world_g, E->parallel.total_surf_proc, processors, &horizon_g);
  MPI_Comm_create(E->parallel.world, horizon_g, &(E->parallel.horizontal_comm));

  if (E->control.verbose) {
    fprintf(E->fp_out,"horizontal group of me=%d loc3=%d\n",E->parallel.me,E->parallel.me_loc[3]);
    for (j=0;j<E->parallel.total_surf_proc;j++) {
      fprintf(E->fp_out,"%d proc=%d\n",j,processors[j]);
    }
    fflush(E->fp_out);
  }

  MPI_Group_free(&horizon_g);
  MPI_Group_free(&world_g);
  free((void *) processors);

  return;
}


static void set_vertical_communicator(struct All_variables *E)
{
  MPI_Group world_g, vertical_g;
  int i,j,k,m;
  int *processors;

  processors = (int *)malloc((E->parallel.nprocz+2)*sizeof(int));

  m = E->sphere.capid[1] - 1;  /* assume 1 cap per proc. */
  i = E->parallel.me_loc[1];
  j = E->parallel.me_loc[2];

  for (k=0;k<E->parallel.nprocz;k++) {
      processors[k] = E->parallel.loc2proc_map[m][i][j][k];
  }

  MPI_Comm_group(E->parallel.world, &world_g);
  MPI_Group_incl(world_g, E->parallel.nprocz, processors, &vertical_g);
  MPI_Comm_create(E->parallel.world, vertical_g, &(E->parallel.vertical_comm));

  if (E->control.verbose) {
    fprintf(E->fp_out,"vertical group of me=%d loc1=%d loc2=%d\n",E->parallel.me,E->parallel.me_loc[1],E->parallel.me_loc[2]);
    for (j=0;j<E->parallel.nprocz;j++) {
      fprintf(E->fp_out,"%d proc=%d\n",j,processors[j]);
    }
    fflush(E->fp_out);
  }

  MPI_Group_free(&vertical_g);
  MPI_Group_free(&world_g);
  free((void *) processors);
}


/* =========================================================================
get element information for each processor.
 ========================================================================= */

void full_parallel_domain_decomp0(struct All_variables *E)
  {

  int i,nox,noz,noy,me;

  me = E->parallel.me;

  E->lmesh.elx = E->mesh.elx/E->parallel.nprocx;
  E->lmesh.elz = E->mesh.elz/E->parallel.nprocz;
  E->lmesh.ely = E->mesh.ely/E->parallel.nprocy;
  E->lmesh.nox = E->lmesh.elx + 1;
  E->lmesh.noz = E->lmesh.elz + 1;
  E->lmesh.noy = E->lmesh.ely + 1;

  E->lmesh.exs = E->parallel.me_loc[1]*E->lmesh.elx;
  E->lmesh.eys = E->parallel.me_loc[2]*E->lmesh.ely;
  E->lmesh.ezs = E->parallel.me_loc[3]*E->lmesh.elz;
  E->lmesh.nxs = E->parallel.me_loc[1]*E->lmesh.elx+1;
  E->lmesh.nys = E->parallel.me_loc[2]*E->lmesh.ely+1;
  E->lmesh.nzs = E->parallel.me_loc[3]*E->lmesh.elz+1;

  E->lmesh.nno = E->lmesh.noz*E->lmesh.nox*E->lmesh.noy;
  E->lmesh.nel = E->lmesh.ely*E->lmesh.elx*E->lmesh.elz;
  E->lmesh.npno = E->lmesh.nel;

  E->lmesh.nsf = E->lmesh.nno/E->lmesh.noz;
  E->lmesh.snel = E->lmesh.elx*E->lmesh.ely;

  for(i=E->mesh.levmax;i>=E->mesh.levmin;i--)   {

     if (E->control.NMULTIGRID)  {
        nox = E->lmesh.elx/(int)pow(2.0,(double)(E->mesh.levmax-i))+1;
        noy = E->lmesh.ely/(int)pow(2.0,(double)(E->mesh.levmax-i))+1;
        noz = E->lmesh.elz/(int)pow(2.0,(double)(E->mesh.levmax-i))+1;
        E->parallel.redundant[i]=0;
        }
     else
        { noz = E->lmesh.noz;
          noy = E->lmesh.noy;
          nox = E->lmesh.nox;
        }

     E->lmesh.ELX[i] = nox-1;
     E->lmesh.ELY[i] = noy-1;
     E->lmesh.ELZ[i] = noz-1;
     E->lmesh.NOZ[i] = noz;
     E->lmesh.NOY[i] = noy;
     E->lmesh.NOX[i] = nox;
     E->lmesh.NNO[i] = nox * noz * noy;
     E->lmesh.NNOV[i] = E->lmesh.NNO[i];
     E->lmesh.SNEL[i] = E->lmesh.ELX[i]*E->lmesh.ELY[i];

     E->lmesh.NEL[i] = (nox-1) * (noz-1) * (noy-1);
     E->lmesh.NPNO[i] = E->lmesh.NEL[i] ;

     E->lmesh.NEQ[i] = E->mesh.nsd * E->lmesh.NNOV[i] ;

     E->lmesh.EXS[i] = E->parallel.me_loc[1]*E->lmesh.ELX[i];
     E->lmesh.EYS[i] = E->parallel.me_loc[2]*E->lmesh.ELY[i];
     E->lmesh.EZS[i] = E->parallel.me_loc[3]*E->lmesh.ELZ[i];
     E->lmesh.NXS[i] = E->parallel.me_loc[1]*E->lmesh.ELX[i]+1;
     E->lmesh.NYS[i] = E->parallel.me_loc[2]*E->lmesh.ELY[i]+1;
     E->lmesh.NZS[i] = E->parallel.me_loc[3]*E->lmesh.ELZ[i]+1;
     }

/*
fprintf(stderr,"b %d %d %d %d %d %d %d\n",E->parallel.me,E->parallel.me_loc[1],E->parallel.me_loc[2],E->parallel.me_loc[3],E->lmesh.nzs,E->lmesh.nys,E->lmesh.noy);
*/
/* parallel_process_termination();
*/
  return;
  }



/* ============================================
 determine boundary nodes for
 exchange info across the boundaries
 ============================================ */

void full_parallel_domain_boundary_nodes(E)
  struct All_variables *E;
  {

  void parallel_process_termination();

  int m,i,ii,j,k,l,node,el,lnode;
  int lev,ele,elx,elz,ely,nel,nno,nox,noz,noy;
  FILE *fp;
  char output_file[255];

  for(lev=E->mesh.gridmin;lev<=E->mesh.gridmax;lev++)   {
      nel = E->lmesh.NEL[lev];
      elx = E->lmesh.ELX[lev];
      elz = E->lmesh.ELZ[lev];
      ely = E->lmesh.ELY[lev];
      nox = E->lmesh.NOX[lev];
      noy = E->lmesh.NOY[lev];
      noz = E->lmesh.NOZ[lev];
      nno = E->lmesh.NNO[lev];

/* do the ZOY boundary elements first */
      lnode = 0;
      ii =1;              /* left */
      for(j=1;j<=noz;j++)
      for(k=1;k<=noy;k++)  {
        node = j + (k-1)*noz*nox;
        E->parallel.NODE[lev][++lnode].bound[ii] =  node;
        E->NODE[lev][node] = E->NODE[lev][node] | OFFSIDE;
        }

      E->parallel.NUM_NNO[lev].bound[ii] = lnode;


      lnode = 0;
      ii =2;              /* right */
      for(j=1;j<=noz;j++)
      for(k=1;k<=noy;k++)      {
        node = (nox-1)*noz + j + (k-1)*noz*nox;
        E->parallel.NODE[lev][++lnode].bound[ii] =  node;
        E->NODE[lev][node] = E->NODE[lev][node] | OFFSIDE;
        }

      E->parallel.NUM_NNO[lev].bound[ii] = lnode;


/* do XOY boundary elements */
      ii=5;                           /* bottom */
      lnode=0;
      for(k=1;k<=noy;k++)
      for(i=1;i<=nox;i++)   {
        node = (k-1)*nox*noz + (i-1)*noz + 1;
        E->parallel.NODE[lev][++lnode].bound[ii] = node;
        E->NODE[lev][node] = E->NODE[lev][node] | OFFSIDE;
        }

      E->parallel.NUM_NNO[lev].bound[ii] = lnode;

      ii=6;                           /* top  */
      lnode=0;
      for(k=1;k<=noy;k++)
      for(i=1;i<=nox;i++)  {
        node = (k-1)*nox*noz + i*noz;
        E->parallel.NODE[lev][++lnode].bound[ii] = node;
        E->NODE[lev][node] = E->NODE[lev][node] | OFFSIDE;
        }

      E->parallel.NUM_NNO[lev].bound[ii] = lnode;


/* do XOZ boundary elements for 3D */
      ii=3;                           /* front */
      lnode=0;
      for(j=1;j<=noz;j++)
      for(i=1;i<=nox;i++)   {
        node = (i-1)*noz +j;
        E->parallel.NODE[lev][++lnode].bound[ii] = node;
        E->NODE[lev][node] = E->NODE[lev][node] | OFFSIDE;
        }

      E->parallel.NUM_NNO[lev].bound[ii] = lnode;

      ii=4;                           /* rear */
      lnode=0;
      for(j=1;j<=noz;j++)
      for(i=1;i<=nox;i++)   {
        node = noz*nox*(noy-1) + (i-1)*noz +j;
        E->parallel.NODE[lev][++lnode].bound[ii] = node;
        E->NODE[lev][node] = E->NODE[lev][node] | OFFSIDE;
        }

      E->parallel.NUM_NNO[lev].bound[ii] = lnode;

      /* determine the overlapped nodes between caps or between proc */

      /* horizontal direction:
         all nodes at right (ix==nox) and front (iy==1) faces
         are skipped */
      for (lnode=1;lnode<=E->parallel.NUM_NNO[lev].bound[2];lnode++) {
          node = E->parallel.NODE[lev][lnode].bound[2];
          E->NODE[lev][node] = E->NODE[lev][node] | SKIP;
      }

      for (lnode=1;lnode<=E->parallel.NUM_NNO[lev].bound[3];lnode++) {
          node = E->parallel.NODE[lev][lnode].bound[3];
          E->NODE[lev][node] = E->NODE[lev][node] | SKIP;
      }

      /* nodes at N/S poles are skipped by all proc.
         add them back here */

      /* north pole is at the front left proc. of 1st cap */
      if (E->sphere.capid[1] == 1 &&
          E->parallel.me_loc[1] == 0 &&
          E->parallel.me_loc[2] == 0)
          for(j=1;j<=noz;j++) {
              node = j;
              E->NODE[lev][node] = E->NODE[lev][node] & ~SKIP;
          }

      /* south pole is at the back right proc. of final cap */
      if (E->sphere.capid[1] == E->sphere.caps &&
          E->parallel.me_loc[1] == E->parallel.nprocx-1 &&
          E->parallel.me_loc[2] == E->parallel.nprocy-1)
          for(j=1;j<=noz;j++) {
              node = j*nox*noy;
              E->NODE[lev][node] = E->NODE[lev][node] & ~SKIP;
          }

      /* radial direction is easy:
         all top nodes except those at top processors are skipped */
      if (E->parallel.me_loc[3]!=E->parallel.nprocz-1 )
          for (lnode=1;lnode<=E->parallel.NUM_NNO[lev].bound[6];lnode++) {
              node = E->parallel.NODE[lev][lnode].bound[6];
              E->NODE[lev][node] = E->NODE[lev][node] | SKIP;
          }

    }   /* end for level */


if (E->control.verbose) {
 fprintf(E->fp_out,"output_shared_nodes %d \n",E->parallel.me);
 for(lev=E->mesh.gridmax;lev>=E->mesh.gridmin;lev--)
    fprintf(E->fp_out,"lev=%d  me=%d capid=%d\n",lev,E->parallel.me,E->sphere.capid[1]);
    for (ii=1;ii<=6;ii++)
      for (i=1;i<=E->parallel.NUM_NNO[lev].bound[ii];i++)
        fprintf(E->fp_out,"ii=%d   %d %d \n",ii,i,E->parallel.NODE[lev][i].bound[ii]);

    lnode=0;
    for (node=1;node<=E->lmesh.NNO[lev];node++)
      if((E->NODE[lev][node] & SKIP)) {
        lnode++;
        fprintf(E->fp_out,"skip %d %d \n",lnode,node);
        }
 fflush(E->fp_out);
  }
}


/* ============================================
 determine communication routs  and boundary ID for
 exchange info across the boundaries
 assuming fault nodes are in the top row of processors
 ============================================ */

static void face_eqn_node_to_pass(struct All_variables *, int, int, int);
static void line_eqn_node_to_pass(struct All_variables *, int, int, int, int, int);

void full_parallel_communication_routs_v(E)
  struct All_variables *E;
  {

  int m,i,ii,j,k,l,node,el,elt,lnode,jj,doff,target;
  int lev,elx,elz,ely,nno,nox,noz,noy,p,kkk,kk,kf,kkkp;
  int me, nprocx,nprocy,nprocz,nprocxz;
  int tscaps,cap,scap,large,npass,lx,ly,lz,temp,layer;

  const int dims=E->mesh.nsd;

  me = E->parallel.me;
  nprocx = E->parallel.nprocx;
  nprocy = E->parallel.nprocy;
  nprocz = E->parallel.nprocz;
  nprocxz = nprocx * nprocz;
  tscaps = E->parallel.total_surf_proc;
  lx = E->parallel.me_loc[1];
  ly = E->parallel.me_loc[2];
  lz = E->parallel.me_loc[3];

        /* determine the communications in horizontal direction        */
  for(lev=E->mesh.gridmax;lev>=E->mesh.gridmin;lev--)       {
    nox = E->lmesh.NOX[lev];
    noz = E->lmesh.NOZ[lev];
    noy = E->lmesh.NOY[lev];

      cap = E->sphere.capid[1] - 1;  /* which cap I am in (0~11) */

      /* -X face */
      npass = ii = 1;
      if (lx != 0)
	target = E->parallel.loc2proc_map[cap][lx-1][ly][lz];
      else
	if ( cap%3 != 0) {
	  temp = (cap+2) % 12;
	  target = E->parallel.loc2proc_map[temp][nprocx-1][ly][lz];
	}
	else {
	  temp = (cap+3) % 12;
	  target = E->parallel.loc2proc_map[temp][ly][0][lz];
	}

      E->parallel.PROCESSOR[lev].pass[npass] = target;
      face_eqn_node_to_pass(E,lev,npass,ii);

      /* +X face */
      npass = ii = 2;
      if (lx != nprocx-1)
	target = E->parallel.loc2proc_map[cap][lx+1][ly][lz];
      else
	if ( cap%3 != 2) {
	  temp = (12+cap-2) % 12;
	  target = E->parallel.loc2proc_map[temp][0][ly][lz];
	}
	else {
	  temp = (12+cap-3) % 12;
	  target = E->parallel.loc2proc_map[temp][ly][nprocy-1][lz];
	}
      E->parallel.PROCESSOR[lev].pass[npass] = target;
      face_eqn_node_to_pass(E,lev,npass,ii);

      /* -Y face */
      npass = ii = 3;
      if (ly != 0)
	target = E->parallel.loc2proc_map[cap][lx][ly-1][lz];
      else
	if ( cap%3 != 0) {
	  temp = cap-1;
	  target = E->parallel.loc2proc_map[temp][lx][nprocy-1][lz];
	}
	else {
	  temp = (12+cap-3) % 12;
	  target = E->parallel.loc2proc_map[temp][0][lx][lz];
	}

      E->parallel.PROCESSOR[lev].pass[npass] = target;
      face_eqn_node_to_pass(E,lev,npass,ii);

      /* +Y face */
      npass = ii = 4;
      if (ly != nprocy-1)
	target = E->parallel.loc2proc_map[cap][lx][ly+1][lz];
      else
	if ( cap%3 != 2) {
	  temp = cap+1;
	  target = E->parallel.loc2proc_map[temp][lx][0][lz];
	}
	else {
	  temp = (cap+3) % 12;
	  target = E->parallel.loc2proc_map[temp][nprocx-1][lx][lz];
	}

      E->parallel.PROCESSOR[lev].pass[npass] = target;
      face_eqn_node_to_pass(E,lev,npass,ii);

      /* do lines parallel to Z */

	/* -X-Y line */
	if (!( (cap%3==1) && (lx==0) && (ly==0) )) {
	  npass ++;
	  if ((cap%3==0) && (lx==0) && (ly==0)) {
	    temp = (cap+6) % 12;
	    target = E->parallel.loc2proc_map[temp][lx][ly][lz];
	  }
	  else if ((cap%3==0) && (lx==0))
	    target = E->parallel.PROCESSOR[lev].pass[1] - nprocz;
	  else if ((cap%3==0) && (ly==0))
	    target = E->parallel.PROCESSOR[lev].pass[3] - nprocxz;
	  else
	    target = E->parallel.PROCESSOR[lev].pass[1] - nprocxz;

	  E->parallel.PROCESSOR[lev].pass[npass] = target;
	  line_eqn_node_to_pass(E,lev,npass,noz,1,1);
	}

	/* +X+Y line */
	if (!( (cap%3==1) && (lx==nprocx-1) && (ly==nprocy-1) )) {
	  npass ++;
	  if ((cap%3==2) && (lx==nprocx-1) && (ly==nprocy-1)) {
	    temp = (cap+6) % 12;
	    target = E->parallel.loc2proc_map[temp][lx][ly][lz];
	  }
	  else if ((cap%3==2) && (lx==nprocx-1))
	    target = E->parallel.PROCESSOR[lev].pass[2] + nprocz;
	  else if ((cap%3==2) && (ly==nprocy-1))
	    target = E->parallel.PROCESSOR[lev].pass[4] + nprocxz;
	  else
	    target = E->parallel.PROCESSOR[lev].pass[2] + nprocxz;

	  E->parallel.PROCESSOR[lev].pass[npass] = target;
	  line_eqn_node_to_pass(E,lev,npass,noz,(noy*nox-1)*noz+1,1);
	}

	/* -X+Y line */
	if (!( (cap%3==2 || cap%3==0) && (lx==0) && (ly==nprocy-1) )) {
	  npass ++;
	  if ((cap%3==2) && (ly==nprocy-1))
	    target = E->parallel.PROCESSOR[lev].pass[4] - nprocxz;
	  else if ((cap%3==0) && (lx==0))
	    target = E->parallel.PROCESSOR[lev].pass[1] + nprocz;
	  else
	    target = E->parallel.PROCESSOR[lev].pass[1] + nprocxz;

	  E->parallel.PROCESSOR[lev].pass[npass] = target;
	  line_eqn_node_to_pass(E,lev,npass,noz,(noy-1)*nox*noz+1,1);
	}

	/* +X-Y line */
	if (!( (cap%3==2 || cap%3==0) && (lx==nprocx-1) && (ly==0) )) {
	  npass ++;
	  if ((cap%3==2) && (lx==nprocx-1))
	    target = E->parallel.PROCESSOR[lev].pass[2] - nprocz;
	  else if ((cap%3==0) && (ly==0))
	    target = E->parallel.PROCESSOR[lev].pass[3] + nprocxz;
	  else
	    target = E->parallel.PROCESSOR[lev].pass[2] - nprocxz;

	  E->parallel.PROCESSOR[lev].pass[npass] = target;
	  line_eqn_node_to_pass(E,lev,npass,noz,(nox-1)*noz+1,1);
	}


      E->parallel.TNUM_PASS[lev] = npass;

  }   /* end for lev  */

  /* determine the communications in vertical direction        */
  for(lev=E->mesh.gridmax;lev>=E->mesh.gridmin;lev--)       {
    kkk = 0;
    for(ii=5;ii<=6;ii++)       {    /* do top & bottom */
      E->parallel.NUM_PASSz[lev].bound[ii] = 1;
      if(lz==0 && ii==5)
	E->parallel.NUM_PASSz[lev].bound[ii] = 0;
      else if(lz==nprocz-1 && ii==6)
	E->parallel.NUM_PASSz[lev].bound[ii] = 0;

      for (p=1;p<=E->parallel.NUM_PASSz[lev].bound[ii];p++)  {
	kkk ++;
	/* determine the pass ID for ii-th boundary and p-th pass */
	kkkp = kkk + E->sphere.max_connections;

	E->parallel.NUM_NODEz[lev].pass[kkk] = 0;
	E->parallel.NUM_NEQz[lev].pass[kkk] = 0;

	  cap = E->sphere.capid[1] - 1;  /* which cap I am in (0~11) */
	  E->parallel.PROCESSORz[lev].pass[kkk] =
	    E->parallel.loc2proc_map[cap][lx][ly][lz+((ii==5)?-1:1)];

	  jj=0;  kk=0;
	  for (k=1;k<=E->parallel.NUM_NNO[lev].bound[ii];k++)   {
	    node = E->parallel.NODE[lev][k].bound[ii];
	    E->parallel.EXCHANGE_NODE[lev][++kk].pass[kkkp] = node;
	    for(doff=1;doff<=dims;doff++)
	      E->parallel.EXCHANGE_ID[lev][++jj].pass[kkkp] =
		E->ID[lev][node].doff[doff];
	  }
	  E->parallel.NUM_NODE[lev].pass[kkkp] = kk;
	  E->parallel.NUM_NEQ[lev].pass[kkkp] = jj;
	  E->parallel.NUM_NODEz[lev].pass[kkk] += kk;
	  E->parallel.NUM_NEQz[lev].pass[kkk] += jj;

      }   /* end for loop p */
    }     /* end for j */

    E->parallel.TNUM_PASSz[lev] = kkk;
  }        /* end for level */



  if(E->control.verbose) {
    for(lev=E->mesh.gridmax;lev>=E->mesh.gridmin;lev--) {
      fprintf(E->fp_out,"output_communication route surface for lev=%d \n",lev);
	fprintf(E->fp_out,"  me= %d cap=%d pass  %d \n",E->parallel.me,E->sphere.capid[1],E->parallel.TNUM_PASS[lev]);
	for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {
	  fprintf(E->fp_out,"proc %d and pass  %d to proc %d with %d eqn and %d node\n",E->parallel.me,k,E->parallel.PROCESSOR[lev].pass[k],E->parallel.NUM_NEQ[lev].pass[k],E->parallel.NUM_NODE[lev].pass[k]);
	  fprintf(E->fp_out,"Eqn:\n");  
	  for (ii=1;ii<=E->parallel.NUM_NEQ[lev].pass[k];ii++)  
	    fprintf(E->fp_out,"%d %d\n",ii,E->parallel.EXCHANGE_ID[lev][ii].pass[k]);  
	  fprintf(E->fp_out,"Node:\n");  
	  for (ii=1;ii<=E->parallel.NUM_NODE[lev].pass[k];ii++)  
	    fprintf(E->fp_out,"%d %d\n",ii,E->parallel.EXCHANGE_NODE[lev][ii].pass[k]);  
	}

      fprintf(E->fp_out,"output_communication route vertical \n");
      fprintf(E->fp_out," me= %d pass  %d \n",E->parallel.me,E->parallel.TNUM_PASSz[lev]);
      for (k=1;k<=E->parallel.TNUM_PASSz[lev];k++)   {
	kkkp = k + E->sphere.max_connections;
	fprintf(E->fp_out,"proc %d and pass  %d to proc %d\n",E->parallel.me,k,E->parallel.PROCESSORz[lev].pass[k]);
	  fprintf(E->fp_out,"cap=%d eqn=%d node=%d\n",E->sphere.capid[1],E->parallel.NUM_NEQ[lev].pass[kkkp],E->parallel.NUM_NODE[lev].pass[kkkp]);
	  for (ii=1;ii<=E->parallel.NUM_NEQ[lev].pass[kkkp];ii++) 
	    fprintf(E->fp_out,"%d %d\n",ii,E->parallel.EXCHANGE_ID[lev][ii].pass[kkkp]); 
	  for (ii=1;ii<=E->parallel.NUM_NODE[lev].pass[kkkp];ii++) 
	    fprintf(E->fp_out,"%d %d\n",ii,E->parallel.EXCHANGE_NODE[lev][ii].pass[kkkp]); 
      }
    }
    fflush(E->fp_out);
  }
}


/* ============================================
 determine communication routs for
 exchange info across the boundaries on the surfaces
 assuming fault nodes are in the top row of processors
 ============================================ */

void full_parallel_communication_routs_s(E)
  struct All_variables *E;
{

  int i,ii,j,k,l,node,el,elt,lnode,jj,doff;
  int lev,nno,nox,noz,noy,kkk,kk,kf;
  int me,m, nprocz;
  void parallel_process_termination();

  const int dims=E->mesh.nsd;

  me = E->parallel.me;
  nprocz = E->parallel.nprocz;

        /* determine the communications in horizontal direction        */
  for(lev=E->mesh.gridmax;lev>=E->mesh.gridmin;lev--)       {
    nox = E->lmesh.NOX[lev];
    noz = E->lmesh.NOZ[lev];
    noy = E->lmesh.NOY[lev];

      j = E->sphere.capid[1];

      for (kkk=1;kkk<=E->parallel.TNUM_PASS[lev];kkk++) {
        if (kkk<=4) {  /* first 4 communications are for XZ and YZ planes */
          ii = kkk;
          E->parallel.NUM_sNODE[lev].pass[kkk] =
                           E->parallel.NUM_NNO[lev].bound[ii]/noz;

          for (k=1;k<=E->parallel.NUM_sNODE[lev].pass[kkk];k++)   {
            lnode = k;
            node = (E->parallel.NODE[lev][lnode].bound[ii]-1)/noz + 1;
            E->parallel.EXCHANGE_sNODE[lev][k].pass[kkk] = node;
            }  /* end for node k */
          }      /* end for first 4 communications */

        else  {         /* the last FOUR communications are for lines */
          E->parallel.NUM_sNODE[lev].pass[kkk]=1;

          for (k=1;k<=E->parallel.NUM_sNODE[lev].pass[kkk];k++)   {
            node = E->parallel.EXCHANGE_NODE[lev][k].pass[kkk]/noz + 1;
            E->parallel.EXCHANGE_sNODE[lev][k].pass[kkk] = node;
            }  /* end for node k */
          }  /* end for the last FOUR communications */

        }   /* end for kkk  */

    }   /* end for lev  */

  if(E->control.verbose) {
    for(lev=E->mesh.gridmax;lev>=E->mesh.gridmin;lev--) {
      fprintf(E->fp_out,"output_communication route surface for lev=%d \n",lev);
	fprintf(E->fp_out,"  me= %d cap=%d pass  %d \n",E->parallel.me,E->sphere.capid[1],E->parallel.TNUM_PASS[lev]);
	for (k=1;k<=E->parallel.TNUM_PASS[lev];k++) {
	  fprintf(E->fp_out,"proc %d and pass  %d to proc %d with %d node\n",E->parallel.me,k,E->parallel.PROCESSOR[lev].pass[k],E->parallel.NUM_sNODE[lev].pass[k]);
	  fprintf(E->fp_out,"Node:\n");
	  for (ii=1;ii<=E->parallel.NUM_sNODE[lev].pass[k];ii++)
	    fprintf(E->fp_out,"%d %d\n",ii,E->parallel.EXCHANGE_sNODE[lev][ii].pass[k]);
	}

    }
    fflush(E->fp_out);
  }

  return;
}



/* ================================================ */
/* ================================================ */

static void face_eqn_node_to_pass(E,lev,npass,bd)
  struct All_variables *E;
  int lev,npass,bd;
{
  int jj,kk,node,doff;
  const int dims=E->mesh.nsd;

  E->parallel.NUM_NODE[lev].pass[npass] = E->parallel.NUM_NNO[lev].bound[bd];

  jj = 0;
  for (kk=1;kk<=E->parallel.NUM_NODE[lev].pass[npass];kk++)   {
    node = E->parallel.NODE[lev][kk].bound[bd];
    E->parallel.EXCHANGE_NODE[lev][kk].pass[npass] = node;
    for(doff=1;doff<=dims;doff++)
      E->parallel.EXCHANGE_ID[lev][++jj].pass[npass] = E->ID[lev][node].doff[doff];
  }

  E->parallel.NUM_NEQ[lev].pass[npass] = jj;
}

/* ================================================ */
/* ================================================ */

static void line_eqn_node_to_pass(E,lev,npass,num_node,offset,stride)
  struct All_variables *E;
  int lev,npass,num_node,offset,stride;
{
  int jj,kk,node,doff;
  const int dims=E->mesh.nsd;

  E->parallel.NUM_NODE[lev].pass[npass] = num_node;

  jj=0;
  for (kk=1;kk<=E->parallel.NUM_NODE[lev].pass[npass];kk++)   {
    node = (kk-1)*stride + offset;
    E->parallel.EXCHANGE_NODE[lev][kk].pass[npass] = node;
    for(doff=1;doff<=dims;doff++)
      E->parallel.EXCHANGE_ID[lev][++jj].pass[npass] = E->ID[lev][node].doff[doff];
  }

  E->parallel.NUM_NEQ[lev].pass[npass] = jj;
}

void full_exchange_id_d(E, U, lev)
 struct All_variables *E;
 double *U;
 int lev;
 {

 int ii,j,jj,m,k,kk,t_cap,idb,msginfo[8];
 double *S[73],*R[73], *RV, *SV;
 int mid_recv, sizeofk;

 MPI_Status status[100];
 MPI_Status status1;
 MPI_Request request[100];

   for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)  {
     sizeofk = (1+E->parallel.NUM_NEQ[lev].pass[k])*sizeof(double);
     S[k]=(double *)malloc( sizeofk );
     R[k]=(double *)malloc( sizeofk );
   }

 sizeofk = 0;
 for (k=1;k<=E->parallel.TNUM_PASSz[lev];k++)  {
   kk = (1+E->parallel.NUM_NEQz[lev].pass[k])*sizeof(double);
   sizeofk = max(sizeofk, kk);
 }
 RV=(double *)malloc( sizeofk );
 SV=(double *)malloc( sizeofk );

  idb=0;
    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)     {

      for (j=1;j<=E->parallel.NUM_NEQ[lev].pass[k];j++) {
        S[k][j-1] = U[ E->parallel.EXCHANGE_ID[lev][j].pass[k] ];
	}

      if (E->parallel.PROCESSOR[lev].pass[k] != E->parallel.me &&
	  E->parallel.PROCESSOR[lev].pass[k] != -1) {
	  idb ++;
          MPI_Isend(S[k], E->parallel.NUM_NEQ[lev].pass[k], MPI_DOUBLE,
		    E->parallel.PROCESSOR[lev].pass[k], 1,
		    E->parallel.world, &request[idb-1]);
      }
    }           /* for k */

    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {

      if (E->parallel.PROCESSOR[lev].pass[k] != E->parallel.me &&
	  E->parallel.PROCESSOR[lev].pass[k] != -1) {
         idb++;
	 MPI_Irecv(R[k],E->parallel.NUM_NEQ[lev].pass[k], MPI_DOUBLE,
		   E->parallel.PROCESSOR[lev].pass[k], 1,
		   E->parallel.world, &request[idb-1]);
      }
      else {
	for (j=1;j<=E->parallel.NUM_NEQ[lev].pass[k];j++)
           U[ E->parallel.EXCHANGE_ID[lev][j].pass[k] ] += S[k][j-1];
      }
    }      /* for k */

  MPI_Waitall(idb,request,status);

    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {

      if (E->parallel.PROCESSOR[lev].pass[k] != E->parallel.me &&
	  E->parallel.PROCESSOR[lev].pass[k] != -1) {
	for (j=1;j<=E->parallel.NUM_NEQ[lev].pass[k];j++)
	  U[ E->parallel.EXCHANGE_ID[lev][j].pass[k] ] += R[k][j-1];
      }
    }

  /* for vertical direction  */

  for (k=1;k<=E->parallel.TNUM_PASSz[lev];k++)  {
    jj = 0;
    kk = k + E->sphere.max_connections;

      for (j=1;j<=E->parallel.NUM_NEQ[lev].pass[kk];j++)
        SV[jj++] = U[ E->parallel.EXCHANGE_ID[lev][j].pass[kk] ];

    MPI_Sendrecv(SV, E->parallel.NUM_NEQz[lev].pass[k], MPI_DOUBLE,
		 E->parallel.PROCESSORz[lev].pass[k], 1,
                 RV, E->parallel.NUM_NEQz[lev].pass[k], MPI_DOUBLE,
		 E->parallel.PROCESSORz[lev].pass[k], 1,
		 E->parallel.world, &status1);

    jj = 0;
      for (j=1;j<=E->parallel.NUM_NEQ[lev].pass[kk];j++)
        U[ E->parallel.EXCHANGE_ID[lev][j].pass[kk] ] += RV[jj++];
  }

   for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)  {
     free((void*) S[k]);
     free((void*) R[k]);
   }

 free((void*) SV);
 free((void*) RV);
}


/* ================================================ */
/* ================================================ */
static void exchange_node_d(E, U, lev)
 struct All_variables *E;
 double *U;
 int lev;
 {

 int ii,j,jj,m,k,kk,t_cap,idb,msginfo[8];
 double *S[73],*R[73], *RV, *SV;
 int mid_recv, sizeofk;

 MPI_Status status[100];
 MPI_Status status1;
 MPI_Request request[100];

 kk=0;
   for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)  {
     ++kk;
     sizeofk = (1+E->parallel.NUM_NODE[lev].pass[k])*sizeof(double);
     S[kk]=(double *)malloc( sizeofk );
     R[kk]=(double *)malloc( sizeofk );
   }

 idb= 0;
 for (k=1;k<=E->parallel.TNUM_PASSz[lev];k++)  {
   sizeofk = (1+E->parallel.NUM_NODEz[lev].pass[k])*sizeof(double);
   idb = max(idb,sizeofk);
 }

 RV=(double *)malloc( idb );
 SV=(double *)malloc( idb );

  idb=0;
    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)     {
      kk=k;

      for (j=1;j<=E->parallel.NUM_NODE[lev].pass[k];j++)
        S[kk][j-1] = U[ E->parallel.EXCHANGE_NODE[lev][j].pass[k] ];

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me) {
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
         idb ++;
        MPI_Isend(S[kk],E->parallel.NUM_NODE[lev].pass[k],MPI_DOUBLE,
             E->parallel.PROCESSOR[lev].pass[k],1,E->parallel.world,&request[idb-1]);
	}
         }
      }           /* for k */

    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {
      kk=k;

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me)  {
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
         idb++;
         MPI_Irecv(R[kk],E->parallel.NUM_NODE[lev].pass[k],MPI_DOUBLE,
         E->parallel.PROCESSOR[lev].pass[k],1,E->parallel.world,&request[idb-1]);
         }
      }

      else   {
	kk=k;
         for (j=1;j<=E->parallel.NUM_NODE[lev].pass[k];j++)
           U[ E->parallel.EXCHANGE_NODE[lev][j].pass[k] ] += S[kk][j-1];
         }
      }      /* for k */

  MPI_Waitall(idb,request,status);

    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {
      kk=k;

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me)
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
        for (j=1;j<=E->parallel.NUM_NODE[lev].pass[k];j++)
           U[ E->parallel.EXCHANGE_NODE[lev][j].pass[k] ] += R[kk][j-1];
      }
    }

                /* for vertical direction  */

  for (k=1;k<=E->parallel.TNUM_PASSz[lev];k++)  {
    jj = 0;
    kk = k + E->sphere.max_connections;

    for (j=1;j<=E->parallel.NUM_NODE[lev].pass[kk];j++)
      SV[jj++] = U[ E->parallel.EXCHANGE_NODE[lev][j].pass[kk] ];

    MPI_Sendrecv(SV,E->parallel.NUM_NODEz[lev].pass[k],MPI_DOUBLE,
             E->parallel.PROCESSORz[lev].pass[k],1,
                 RV,E->parallel.NUM_NODEz[lev].pass[k],MPI_DOUBLE,
             E->parallel.PROCESSORz[lev].pass[k],1,E->parallel.world,&status1);

    jj = 0;
    for (j=1;j<=E->parallel.NUM_NODE[lev].pass[kk];j++)
      U[ E->parallel.EXCHANGE_NODE[lev][j].pass[kk] ] += RV[jj++];
    }

  kk = 0;
   for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)  {
     kk++;
     free((void*) S[kk]);
     free((void*) R[kk]);
   }

 free((void*) SV);
 free((void*) RV);
}

/* ================================================ */
/* ================================================ */

static void exchange_node_f(E, U, lev)
 struct All_variables *E;
 float *U;
 int lev;
 {

 int ii,j,jj,m,k,kk,t_cap,idb,msginfo[8];

 float *S[73],*R[73], *RV, *SV;
 int mid_recv, sizeofk;

 MPI_Status status[100];
 MPI_Status status1;
 MPI_Request request[100];

 kk=0;
   for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)  {
     ++kk;
     sizeofk = (1+E->parallel.NUM_NODE[lev].pass[k])*sizeof(float);
     S[kk]=(float *)malloc( sizeofk );
     R[kk]=(float *)malloc( sizeofk );
   }

 idb= 0;
 for (k=1;k<=E->parallel.TNUM_PASSz[lev];k++)  {
   sizeofk = (1+E->parallel.NUM_NODEz[lev].pass[k])*sizeof(float);
   idb = max(idb,sizeofk);
 }

 RV=(float *)malloc( idb );
 SV=(float *)malloc( idb );

  idb=0;
    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)     {
      kk=k;

      for (j=1;j<=E->parallel.NUM_NODE[lev].pass[k];j++)
        S[kk][j-1] = U[ E->parallel.EXCHANGE_NODE[lev][j].pass[k] ];

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me) {
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
         idb ++;
        MPI_Isend(S[kk],E->parallel.NUM_NODE[lev].pass[k],MPI_FLOAT,
             E->parallel.PROCESSOR[lev].pass[k],1,E->parallel.world,&request[idb-1]);
	}
         }
      }           /* for k */

    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {
      kk=k;

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me)  {
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
         idb++;
         MPI_Irecv(R[kk],E->parallel.NUM_NODE[lev].pass[k],MPI_FLOAT,
         E->parallel.PROCESSOR[lev].pass[k],1,E->parallel.world,&request[idb-1]);
         }
      }

      else   {
	kk=k;
         for (j=1;j<=E->parallel.NUM_NODE[lev].pass[k];j++)
           U[ E->parallel.EXCHANGE_NODE[lev][j].pass[k] ] += S[kk][j-1];
         }
      }      /* for k */

  MPI_Waitall(idb,request,status);

    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {
      kk=k;

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me)
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
        for (j=1;j<=E->parallel.NUM_NODE[lev].pass[k];j++)
           U[ E->parallel.EXCHANGE_NODE[lev][j].pass[k] ] += R[kk][j-1];
      }
    }

                /* for vertical direction  */

  for (k=1;k<=E->parallel.TNUM_PASSz[lev];k++)  {
    jj = 0;
    kk = k + E->sphere.max_connections;

    for (j=1;j<=E->parallel.NUM_NODE[lev].pass[kk];j++)
      SV[jj++] = U[ E->parallel.EXCHANGE_NODE[lev][j].pass[kk] ];

    MPI_Sendrecv(SV,E->parallel.NUM_NODEz[lev].pass[k],MPI_FLOAT,
             E->parallel.PROCESSORz[lev].pass[k],1,
                 RV,E->parallel.NUM_NODEz[lev].pass[k],MPI_FLOAT,
             E->parallel.PROCESSORz[lev].pass[k],1,E->parallel.world,&status1);

    jj = 0;
    for (j=1;j<=E->parallel.NUM_NODE[lev].pass[kk];j++)
      U[ E->parallel.EXCHANGE_NODE[lev][j].pass[kk] ] += RV[jj++];
    }

  kk = 0;
   for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)  {
     kk++;
     free((void*) S[kk]);
     free((void*) R[kk]);
   }

 free((void*) SV);
 free((void*) RV);
}

void full_exchange_snode_f(struct All_variables *E, float *U1, float *U2, int lev)
 {

 int ii,j,k,m,kk,t_cap,idb,msginfo[8];
 float *S[73],*R[73];
 int mid_recv, sizeofk;

 MPI_Status status[100];
 MPI_Status status1;
 MPI_Request request[100];

   kk=0;
     for (k=1;k<=E->parallel.TNUM_PASS[E->mesh.levmax];k++)  {
       ++kk;
       sizeofk = (1+2*E->parallel.NUM_sNODE[E->mesh.levmax].pass[k])*sizeof(float);
       S[kk]=(float *)malloc( sizeofk );
       R[kk]=(float *)malloc( sizeofk );
       }

  idb=0;
  /* sending */
    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)     {
      kk=k;

      /* pack */
      for (j=1;j<=E->parallel.NUM_sNODE[lev].pass[k];j++)  {
        S[kk][j-1] = U1[ E->parallel.EXCHANGE_sNODE[lev][j].pass[k] ];
        S[kk][j-1+E->parallel.NUM_sNODE[lev].pass[k]]
                   = U2[ E->parallel.EXCHANGE_sNODE[lev][j].pass[k] ];
        }

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me) {
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
         idb ++;
         MPI_Isend(S[kk],2*E->parallel.NUM_sNODE[lev].pass[k],MPI_FLOAT,
             E->parallel.PROCESSOR[lev].pass[k],1,E->parallel.world,&request[idb-1]);
         }
      }
      }           /* for k */

  /* receiving */
    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {
      kk=k;

      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me)  {
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {

         idb ++;
         MPI_Irecv(R[kk],2*E->parallel.NUM_sNODE[lev].pass[k],MPI_FLOAT,
           E->parallel.PROCESSOR[lev].pass[k],1,E->parallel.world,&request[idb-1]);
         }
      }

      else   {
	kk=k;
         for (j=1;j<=E->parallel.NUM_sNODE[lev].pass[k];j++)     {
           U1[ E->parallel.EXCHANGE_sNODE[lev][j].pass[k] ] += S[kk][j-1];
           U2[ E->parallel.EXCHANGE_sNODE[lev][j].pass[k] ] +=
                               S[kk][j-1+E->parallel.NUM_sNODE[lev].pass[k]];
           }
         }
      }      /* for k */

  MPI_Waitall(idb,request,status);

    for (k=1;k<=E->parallel.TNUM_PASS[lev];k++)   {
      kk=k;

      /* unpack */
      if (E->parallel.PROCESSOR[lev].pass[k]!=E->parallel.me)
	if (E->parallel.PROCESSOR[lev].pass[k]!=-1) {
        for (j=1;j<=E->parallel.NUM_sNODE[lev].pass[k];j++)    {
           U1[ E->parallel.EXCHANGE_sNODE[lev][j].pass[k] ] += R[kk][j-1];
           U2[ E->parallel.EXCHANGE_sNODE[lev][j].pass[k] ] +=
                              R[kk][j-1+E->parallel.NUM_sNODE[lev].pass[k]];
           }
	}
      }

  kk=0;
    for (k=1;k<=E->parallel.TNUM_PASS[E->mesh.levmax];k++)  {
      ++kk;
      free((void*) S[kk]);
      free((void*) R[kk]);
    }
}