Esempio n. 1
0
void bail_out (int error) {
   long *global_error;
   long *local_error;
   long *pWrk;
   long *pSync_local;

   int i;
   global_error = prk_shmem_malloc(sizeof(long));
   local_error = prk_shmem_malloc(sizeof(long));
   pWrk = prk_shmem_malloc(sizeof(long)*PRK_SHMEM_BCAST_SYNC_SIZE);
   pSync_local = prk_shmem_malloc(sizeof(long)*PRK_SHMEM_BCAST_SYNC_SIZE);
   for (i = 0; i < PRK_SHMEM_BCAST_SYNC_SIZE; i += 1) {
    pSync_local[i] = PRK_SHMEM_SYNC_VALUE;
   }
   local_error [0] = error;
   shmem_barrier_all ();
   shmem_long_max_to_all (global_error, local_error, 1, 0, 0, prk_shmem_n_pes(), pWrk, pSync_local); 
   if (global_error [0] > 0) {
     prk_shmem_finalize ();
     exit (1);
  }
  return;
}
Esempio n. 2
0
int main(int argc, char ** argv) {
 
  int    Num_procs;       /* number of ranks                                     */
  int    Num_procsx, Num_procsy; /* number of ranks in each coord direction      */
  int    my_ID;           /* SHMEM rank                                          */
  int    my_IDx, my_IDy;  /* coordinates of rank in rank grid                    */
  int    right_nbr;       /* global rank of right neighboring tile               */
  int    left_nbr;        /* global rank of left neighboring tile                */
  int    top_nbr;         /* global rank of top neighboring tile                 */
  int    bottom_nbr;      /* global rank of bottom neighboring tile              */
  DTYPE *top_buf_out;     /* communication buffer                                */
  DTYPE *top_buf_in[2];   /*       "         "                                   */
  DTYPE *bottom_buf_out;  /*       "         "                                   */
  DTYPE *bottom_buf_in[2];/*       "         "                                   */
  DTYPE *right_buf_out;   /*       "         "                                   */
  DTYPE *right_buf_in[2]; /*       "         "                                   */
  DTYPE *left_buf_out;    /*       "         "                                   */
  DTYPE *left_buf_in[2];  /*       "         "                                   */
  int    root = 0;
  int    n, width, height;/* linear global and local grid dimension              */
  int    i, j, ii, jj, kk, it, jt, iter, leftover;  /* dummies                   */
  int    istart, iend;    /* bounds of grid tile assigned to calling rank        */
  int    jstart, jend;    /* bounds of grid tile assigned to calling rank        */
  DTYPE  reference_norm;
  DTYPE  f_active_points; /* interior of grid with respect to stencil            */
  int    stencil_size;    /* number of points in the stencil                     */
  DTYPE  flops;           /* floating point ops per iteration                    */
  int    iterations;      /* number of times to run the algorithm                */
  double avgtime,         /* timing parameters                                   */
         *local_stencil_time, *stencil_time; 
  DTYPE  * RESTRICT in;   /* input grid values                                   */
  DTYPE  * RESTRICT out;  /* output grid values                                  */
  long   total_length_in; /* total required length to store input array          */
  long   total_length_out;/* total required length to store output array         */
  int    error=0;         /* error flag                                          */
  DTYPE  weight[2*RADIUS+1][2*RADIUS+1]; /* weights of points in the stencil     */
  int    *arguments;      /* command line parameters                             */
  int    count_case=4;    /* number of neighbors of a rank                       */
  long   *pSync_bcast;    /* work space for collectives                          */
  long   *pSync_reduce;   /* work space for collectives                          */
  double *pWrk_time;      /* work space for collectives                          */
  DTYPE  *pWrk_norm;      /* work space for collectives                          */
  int    *iterflag;       /* synchronization flags                               */
  int    sw;              /* double buffering switch                             */
  DTYPE  *local_norm, *norm; /* local and global error norms                     */

  /*******************************************************************************
  ** Initialize the SHMEM environment
  ********************************************************************************/
  prk_shmem_init();

  my_ID=prk_shmem_my_pe();
  Num_procs=prk_shmem_n_pes();

  pSync_bcast        = (long *)   prk_shmem_malloc(PRK_SHMEM_BCAST_SYNC_SIZE*sizeof(long));
  pSync_reduce       = (long *)   prk_shmem_malloc(PRK_SHMEM_REDUCE_SYNC_SIZE*sizeof(long));
  pWrk_time          = (double *) prk_shmem_malloc(PRK_SHMEM_REDUCE_MIN_WRKDATA_SIZE*sizeof(double));
  pWrk_norm          = (DTYPE *)  prk_shmem_malloc(PRK_SHMEM_REDUCE_MIN_WRKDATA_SIZE*sizeof(DTYPE));
  local_stencil_time = (double *) prk_shmem_malloc(sizeof(double));
  stencil_time       = (double *) prk_shmem_malloc(sizeof(double));
  local_norm         = (DTYPE *)  prk_shmem_malloc(sizeof(DTYPE));
  norm               = (DTYPE *)  prk_shmem_malloc(sizeof(DTYPE));
  iterflag           = (int *)    prk_shmem_malloc(2*sizeof(int));
  if (!(pSync_bcast && pSync_reduce && pWrk_time && pWrk_norm && iterflag &&
	local_stencil_time && stencil_time && local_norm && norm))
  {
    printf("Could not allocate scalar variables on rank %d\n", my_ID);
    error = 1;
  }
  bail_out(error);

  for(i=0;i<PRK_SHMEM_BCAST_SYNC_SIZE;i++)
    pSync_bcast[i]=PRK_SHMEM_SYNC_VALUE;

  for(i=0;i<PRK_SHMEM_REDUCE_SYNC_SIZE;i++)
    pSync_reduce[i]=PRK_SHMEM_SYNC_VALUE;

  arguments=(int*)prk_shmem_malloc(2*sizeof(int));
 
  /*******************************************************************************
  ** process, test, and broadcast input parameters    
  ********************************************************************************/
 
  if (my_ID == root) {
#ifndef STAR
    printf("ERROR: Compact stencil not supported\n");
    error = 1;
    goto ENDOFTESTS;
#endif
      
    if (argc != 3){
      printf("Usage: %s <# iterations> <array dimension> \n", 
             *argv);
      error = 1;
      goto ENDOFTESTS;
    }
 
    iterations  = atoi(*++argv); 
    arguments[0]=iterations;

    if (iterations < 1){
      printf("ERROR: iterations must be >= 1 : %d \n",iterations);
      error = 1;
      goto ENDOFTESTS;  
    }
 
    n  = atoi(*++argv);
    arguments[1]=n;
    long nsquare = (long)n * (long)n;

    if (nsquare < Num_procs){ 
      printf("ERROR: grid size must be at least # ranks: %ld\n", nsquare);
      error = 1;
      goto ENDOFTESTS;
    }
 
    if (RADIUS < 0) {
      printf("ERROR: Stencil radius %d should be non-negative\n", RADIUS);
      error = 1;
      goto ENDOFTESTS;  
    }
 
    if (2*RADIUS +1 > n) {
      printf("ERROR: Stencil radius %d exceeds grid size %d\n", RADIUS, n);
      error = 1;
      goto ENDOFTESTS;  
    }
 
    ENDOFTESTS:;  
  }
  bail_out(error);
 
  /* determine best way to create a 2D grid of ranks (closest to square, for 
     best surface/volume ratio); we do this brute force for now
  */
  for (Num_procsx=(int) (sqrt(Num_procs+1)); Num_procsx>0; Num_procsx--) {
    if (!(Num_procs%Num_procsx)) {
      Num_procsy = Num_procs/Num_procsx;
      break;
    }
  }      
  my_IDx = my_ID%Num_procsx;
  my_IDy = my_ID/Num_procsx;
  /* compute neighbors; don't worry about dropping off the edges of the grid */
  right_nbr  = my_ID+1;
  left_nbr   = my_ID-1;
  top_nbr    = my_ID+Num_procsx;
  bottom_nbr = my_ID-Num_procsx;

  iterflag[0] = iterflag[1] = 0;

  if(my_IDx==0)            count_case--;
  if(my_IDx==Num_procsx-1) count_case--;
  if(my_IDy==0)            count_case--;
  if(my_IDy==Num_procsy-1) count_case--;
 
  if (my_ID == root) {
    printf("Parallel Research Kernels version %s\n", PRKVERSION);
    printf("SHMEM stencil execution on 2D grid\n");
    printf("Number of ranks        = %d\n", Num_procs);
    printf("Grid size              = %d\n", n);
    printf("Radius of stencil      = %d\n", RADIUS);
    printf("Tiles in x/y-direction = %d/%d\n", Num_procsx, Num_procsy);
    printf("Type of stencil        = star\n");
#ifdef DOUBLE
    printf("Data type              = double precision\n");
#else
    printf("Data type              = single precision\n");
#endif
#if LOOPGEN
    printf("Script used to expand stencil loop body\n");
#else
    printf("Compact representation of stencil loop body\n");
#endif
#if SPLITFENCE
    printf("Split fence            = ON\n");
#else
    printf("Split fence            = OFF\n");
#endif
    printf("Number of iterations   = %d\n", iterations);
  }

  shmem_barrier_all();
 
  shmem_broadcast32(&arguments[0], &arguments[0], 2, root, 0, 0, Num_procs, pSync_bcast);

  iterations=arguments[0];
  n=arguments[1];

  shmem_barrier_all();
  prk_shmem_free(arguments);
 
  /* compute amount of space required for input and solution arrays             */
  
  width = n/Num_procsx;
  leftover = n%Num_procsx;
  if (my_IDx<leftover) {
    istart = (width+1) * my_IDx; 
    iend = istart + width + 1;
  }
  else {
    istart = (width+1) * leftover + width * (my_IDx-leftover);
    iend = istart + width;
  }
  
  width = iend - istart + 1;
  if (width == 0) {
    printf("ERROR: rank %d has no work to do\n", my_ID);
    error = 1;
  }
  bail_out(error);
 
  height = n/Num_procsy;
  leftover = n%Num_procsy;
  if (my_IDy<leftover) {
    jstart = (height+1) * my_IDy; 
    jend = jstart + height + 1;
  }
  else {
    jstart = (height+1) * leftover + height * (my_IDy-leftover);
    jend = jstart + height;
  }
  
  height = jend - jstart + 1;
  if (height == 0) {
    printf("ERROR: rank %d has no work to do\n", my_ID);
    error = 1;
  }
  bail_out(error);
 
  if (width < RADIUS || height < RADIUS) {
    printf("ERROR: rank %d has work tile smaller then stencil radius\n",
           my_ID);
    error = 1;
  }
  bail_out(error);
 
  total_length_in = (width+2*RADIUS);
  total_length_in *= (height+2*RADIUS);
  total_length_in *= sizeof(DTYPE);

  total_length_out = width;
  total_length_out *= height;
  total_length_out *= sizeof(DTYPE);
 
  in  = (DTYPE *) malloc(total_length_in);
  out = (DTYPE *) malloc(total_length_out);
  if (!in || !out) {
    printf("ERROR: rank %d could not allocate space for input/output array\n",
            my_ID);
    error = 1;
  }
  bail_out(error);
 
  /* fill the stencil weights to reflect a discrete divergence operator         */
  for (jj=-RADIUS; jj<=RADIUS; jj++) for (ii=-RADIUS; ii<=RADIUS; ii++)
    WEIGHT(ii,jj) = (DTYPE) 0.0;
  stencil_size = 4*RADIUS+1;

  for (ii=1; ii<=RADIUS; ii++) {
    WEIGHT(0, ii) = WEIGHT( ii,0) =  (DTYPE) (1.0/(2.0*ii*RADIUS));
    WEIGHT(0,-ii) = WEIGHT(-ii,0) = -(DTYPE) (1.0/(2.0*ii*RADIUS));
  }
 
  norm[0] = (DTYPE) 0.0;
  f_active_points = (DTYPE) (n-2*RADIUS)*(DTYPE) (n-2*RADIUS);

  /* intialize the input and output arrays                                     */
  for (j=jstart; j<jend; j++) for (i=istart; i<iend; i++) {
    IN(i,j)  = COEFX*i+COEFY*j;
    OUT(i,j) = (DTYPE)0.0;
  }

  /* allocate communication buffers for halo values                            */
  top_buf_out=(DTYPE*)malloc(2*sizeof(DTYPE)*RADIUS*width);
  if (!top_buf_out) {
    printf("ERROR: Rank %d could not allocate output comm buffers for y-direction\n", my_ID);
    error = 1;
  }
  bail_out(error);
  bottom_buf_out = top_buf_out+RADIUS*width;

  top_buf_in[0]=(DTYPE*)prk_shmem_malloc(4*sizeof(DTYPE)*RADIUS*width);
  if(!top_buf_in)
  {
    printf("ERROR: Rank %d could not allocate input comm buffers for y-direction\n", my_ID);
    error=1;
  }
  bail_out(error);
  top_buf_in[1]    = top_buf_in[0]    + RADIUS*width;
  bottom_buf_in[0] = top_buf_in[1]    + RADIUS*width;
  bottom_buf_in[1] = bottom_buf_in[0] + RADIUS*width;
 
  right_buf_out=(DTYPE*)malloc(2*sizeof(DTYPE)*RADIUS*height);
  if (!right_buf_out) {
    printf("ERROR: Rank %d could not allocate output comm buffers for x-direction\n", my_ID);
    error = 1;
  }
  bail_out(error);
  left_buf_out=right_buf_out+RADIUS*height;

  right_buf_in[0]=(DTYPE*)prk_shmem_malloc(4*sizeof(DTYPE)*RADIUS*height);
  if(!right_buf_in)
  {
    printf("ERROR: Rank %d could not allocate input comm buffers for x-dimension\n", my_ID);
    error=1;
  }
  bail_out(error);
  right_buf_in[1] = right_buf_in[0] + RADIUS*height;
  left_buf_in[0]  = right_buf_in[1] + RADIUS*height;
  left_buf_in[1]  = left_buf_in[0]  + RADIUS*height;

  /* make sure all symmetric heaps are allocated before being used  */
  shmem_barrier_all();

  for (iter = 0; iter<=iterations; iter++){

    /* start timer after a warmup iteration */
    if (iter == 1) { 
      shmem_barrier_all();
      local_stencil_time[0] = wtime();
    }
    /* sw determines which incoming buffer to select */
    sw = iter%2;

    /* need to fetch ghost point data from neighbors */

    if (my_IDy < Num_procsy-1) {
      for (kk=0,j=jend-RADIUS; j<=jend-1; j++) for (i=istart; i<=iend; i++) {
          top_buf_out[kk++]= IN(i,j);
      }
      shmem_putmem(bottom_buf_in[sw], top_buf_out, RADIUS*width*sizeof(DTYPE), top_nbr);
#if SPLITFENCE
      shmem_fence();
      shmem_int_inc(&iterflag[sw], top_nbr);
#endif
    }
    if (my_IDy > 0) {
      for (kk=0,j=jstart; j<=jstart+RADIUS-1; j++) for (i=istart; i<=iend; i++) {
          bottom_buf_out[kk++]= IN(i,j);
      }
      shmem_putmem(top_buf_in[sw], bottom_buf_out, RADIUS*width*sizeof(DTYPE), bottom_nbr);
#if SPLITFENCE
      shmem_fence();
      shmem_int_inc(&iterflag[sw], bottom_nbr);
#endif
    }

    if(my_IDx < Num_procsx-1) {
      for(kk=0,j=jstart;j<=jend;j++) for(i=iend-RADIUS;i<=iend-1;i++) {
	right_buf_out[kk++]=IN(i,j);
      }
      shmem_putmem(left_buf_in[sw], right_buf_out, RADIUS*height*sizeof(DTYPE), right_nbr);
#if SPLITFENCE
      shmem_fence();
      shmem_int_inc(&iterflag[sw], right_nbr);
#endif
    }

    if(my_IDx>0) {
      for(kk=0,j=jstart;j<=jend;j++) for(i=istart;i<=istart+RADIUS-1;i++) {
	left_buf_out[kk++]=IN(i,j);
      }
      shmem_putmem(right_buf_in[sw], left_buf_out, RADIUS*height*sizeof(DTYPE), left_nbr);
#if SPLITFENCE
      shmem_fence();
      shmem_int_inc(&iterflag[sw], left_nbr);
#endif
    }

#if SPLITFENCE == 0
    shmem_fence();
    if(my_IDy<Num_procsy-1) shmem_int_inc(&iterflag[sw], top_nbr);
    if(my_IDy>0)            shmem_int_inc(&iterflag[sw], bottom_nbr);
    if(my_IDx<Num_procsx-1) shmem_int_inc(&iterflag[sw], right_nbr);
    if(my_IDx>0)            shmem_int_inc(&iterflag[sw], left_nbr);
#endif

    shmem_int_wait_until(&iterflag[sw], SHMEM_CMP_EQ, count_case*(iter/2+1));

    if (my_IDy < Num_procsy-1) {
      for (kk=0,j=jend; j<=jend+RADIUS-1; j++) for (i=istart; i<=iend; i++) {
          IN(i,j) = top_buf_in[sw][kk++];
      }      
    }
    if (my_IDy > 0) {
      for (kk=0,j=jstart-RADIUS; j<=jstart-1; j++) for (i=istart; i<=iend; i++) {
          IN(i,j) = bottom_buf_in[sw][kk++];
      }      
    }

    if (my_IDx < Num_procsx-1) {
      for (kk=0,j=jstart; j<=jend; j++) for (i=iend; i<=iend+RADIUS-1; i++) {
          IN(i,j) = right_buf_in[sw][kk++];
      }      
    }
    if (my_IDx > 0) {
      for (kk=0,j=jstart; j<=jend; j++) for (i=istart-RADIUS; i<=istart-1; i++) {
          IN(i,j) = left_buf_in[sw][kk++];
      }      
    }
 
    /* Apply the stencil operator */
    for (j=MAX(jstart,RADIUS); j<=MIN(n-RADIUS-1,jend); j++) {
      for (i=MAX(istart,RADIUS); i<=MIN(n-RADIUS-1,iend); i++) {
        #if LOOPGEN
          #include "loop_body_star.incl"
        #else
          for (jj=-RADIUS; jj<=RADIUS; jj++) OUT(i,j) += WEIGHT(0,jj)*IN(i,j+jj);
          for (ii=-RADIUS; ii<0; ii++)       OUT(i,j) += WEIGHT(ii,0)*IN(i+ii,j);
          for (ii=1; ii<=RADIUS; ii++)       OUT(i,j) += WEIGHT(ii,0)*IN(i+ii,j);
        #endif
      }
    }
 
    /* add constant to solution to force refresh of neighbor data, if any */
    for (j=jstart; j<jend; j++) for (i=istart; i<iend; i++) IN(i,j)+= 1.0;
 
  }
 
  local_stencil_time[0] = wtime() - local_stencil_time[0];

  shmem_barrier_all();

  shmem_double_max_to_all(&stencil_time[0], &local_stencil_time[0], 1, 0, 0,
                          Num_procs, pWrk_time, pSync_reduce);
  
  /* compute L1 norm in parallel                                                */
  local_norm[0] = (DTYPE) 0.0;
  for (j=MAX(jstart,RADIUS); j<MIN(n-RADIUS,jend); j++) {
    for (i=MAX(istart,RADIUS); i<MIN(n-RADIUS,iend); i++) {
      local_norm[0] += (DTYPE)ABS(OUT(i,j));
    }
  }

  shmem_barrier_all();
 
#ifdef DOUBLE
  shmem_double_sum_to_all(&norm[0], &local_norm[0], 1, 0, 0, Num_procs, pWrk_norm, pSync_reduce);
#else
  shmem_float_sum_to_all(&norm[0], &local_norm[0], 1, 0, 0, Num_procs, pWrk_norm, pSync_reduce);
#endif
 
  /*******************************************************************************
  ** Analyze and output results.
  ********************************************************************************/
 
/* verify correctness                                                            */
  if (my_ID == root) {
    norm[0] /= f_active_points;
    if (RADIUS > 0) {
      reference_norm = (DTYPE) (iterations+1) * (COEFX + COEFY);
    }
    else {
      reference_norm = (DTYPE) 0.0;
    }
    if (ABS(norm[0]-reference_norm) > EPSILON) {
      printf("ERROR: L1 norm = "FSTR", Reference L1 norm = "FSTR"\n",
             norm[0], reference_norm);
      error = 1;
    }
    else {
      printf("Solution validates\n");
#ifdef VERBOSE
      printf("Reference L1 norm = "FSTR", L1 norm = "FSTR"\n", 
             reference_norm, norm[0]);
#endif
    }
  }
  bail_out(error);
 
  if (my_ID == root) {
    /* flops/stencil: 2 flops (fma) for each point in the stencil, 
       plus one flop for the update of the input of the array        */
    flops = (DTYPE) (2*stencil_size+1) * f_active_points;
    avgtime = stencil_time[0]/iterations;
    printf("Rate (MFlops/s): "FSTR"  Avg time (s): %lf\n",
           1.0E-06 * flops/avgtime, avgtime);
  }
 

  prk_shmem_free(top_buf_in);
  prk_shmem_free(right_buf_in);
  free(top_buf_out);
  free(right_buf_out);

  prk_shmem_free(pSync_bcast);
  prk_shmem_free(pSync_reduce);
  prk_shmem_free(pWrk_time);
  prk_shmem_free(pWrk_norm);

  prk_shmem_finalize();

  exit(EXIT_SUCCESS);
}
Esempio n. 3
0
int main(int argc, char ** argv)
{
  long Block_order;        /* number of columns owned by rank       */
  int Block_size;          /* size of a single block                */
  int Colblock_size;       /* size of column block                  */
  int Tile_order=32;       /* default Tile order                    */
  int tiling;              /* boolean: true if tiling is used       */
  int Num_procs;           /* number of ranks                       */
  int order;               /* order of overall matrix               */
  int bufferCount;         /* number of input buffers               */
  int targetBuffer;        /* buffer with which to communicate      */
  int send_to, recv_from;  /* ranks with which to communicate       */
  long bytes;              /* combined size of matrices             */
  int my_ID;               /* rank                                  */
  int root=0;              /* rank of root                          */
  int iterations;          /* number of times to do the transpose   */
  long i, j, it, jt, istart;/* dummies                              */
  int iter;                /* index of iteration                    */
  int phase;               /* phase inside staged communication     */
  int colstart;            /* starting column for owning rank       */
  int error;               /* error flag                            */
  double *A_p;             /* original matrix column block          */
  double *B_p;             /* transposed matrix column block        */
  double **Work_in_p;      /* workspace for the transpose function  */
  double *Work_out_p;      /* workspace for the transpose function  */
  double epsilon = 1.e-8;  /* error tolerance                       */
  double avgtime;          /* timing parameters                     */
  long   *pSync_bcast;     /* work space for collectives            */
  long   *pSync_reduce;    /* work space for collectives            */
  double *pWrk;            /* work space for SHMEM collectives      */
  double *local_trans_time, 
         *trans_time;      /* timing parameters                     */
  double *abserr, 
         *abserr_tot;      /* local and aggregate error             */
  int    *send_flag,
         *recv_flag;       /* synchronization flags                 */
  int    *arguments;       /* command line arguments                */

/*********************************************************************
** Initialize the SHMEM environment
*********************************************************************/

  prk_shmem_init();
  my_ID=prk_shmem_my_pe();
  Num_procs=prk_shmem_n_pes();

  if (my_ID == root) {
    printf("Parallel Research Kernels version %s\n", PRKVERSION);
    printf("SHMEM matrix transpose: B = A^T\n");
  }

// initialize sync variables for error checks
  pSync_bcast      = (long *)   prk_shmem_align(prk_get_alignment(),PRK_SHMEM_BCAST_SYNC_SIZE*sizeof(long));
  pSync_reduce     = (long *)   prk_shmem_align(prk_get_alignment(),PRK_SHMEM_REDUCE_SYNC_SIZE*sizeof(long));
  pWrk             = (double *) prk_shmem_align(prk_get_alignment(),sizeof(double) * PRK_SHMEM_REDUCE_MIN_WRKDATA_SIZE);
  local_trans_time = (double *) prk_shmem_align(prk_get_alignment(),sizeof(double));
  trans_time       = (double *) prk_shmem_align(prk_get_alignment(),sizeof(double));
  arguments        = (int *)    prk_shmem_align(prk_get_alignment(),4*sizeof(int));
  abserr           = (double *) prk_shmem_align(prk_get_alignment(),2*sizeof(double));
  abserr_tot       = abserr + 1;
  if (!pSync_bcast || !pSync_reduce || !pWrk || !local_trans_time ||
      !trans_time || !arguments || !abserr) {
    printf("Rank %d could not allocate scalar work space on symm heap\n", my_ID);
    error = 1;
    goto ENDOFTESTS;
  }

  for(i=0;i<PRK_SHMEM_BCAST_SYNC_SIZE;i++)
    pSync_bcast[i]=PRK_SHMEM_SYNC_VALUE;

  for(i=0;i<PRK_SHMEM_REDUCE_SYNC_SIZE;i++)
    pSync_reduce[i]=PRK_SHMEM_SYNC_VALUE;

/*********************************************************************
** process, test and broadcast input parameters
*********************************************************************/
  error = 0;
  if (my_ID == root) {
    if (argc != 4 && argc != 5){
      printf("Usage: %s <# iterations> <matrix order> <# buffers> [Tile size]\n",
                                                               *argv);
      error = 1; goto ENDOFTESTS;
    }

    iterations  = atoi(*++argv);
    arguments[0]=iterations;
    if(iterations < 1){
      printf("ERROR: iterations must be >= 1 : %d \n",iterations);
      error = 1; goto ENDOFTESTS;
    }

    order = atoi(*++argv);
    arguments[1]=order;
    if (order < Num_procs) {
      printf("ERROR: matrix order %d should at least # procs %d\n", 
             order, Num_procs);
      error = 1; goto ENDOFTESTS;
    }
    if (order%Num_procs) {
      printf("ERROR: matrix order %d should be divisible by # procs %d\n",
             order, Num_procs);
      error = 1; goto ENDOFTESTS;
    }

    bufferCount = atoi(*++argv);
    arguments[2]=bufferCount;
    if (Num_procs > 1) {
      if ((bufferCount < 1) || (bufferCount >= Num_procs)) {
        printf("ERROR: bufferCount must be >= 1 and < # procs : %d\n", bufferCount);
        error = 1; goto ENDOFTESTS;
      }
    }

    if (argc == 5) Tile_order = atoi(*++argv);
    arguments[3]=Tile_order;

    ENDOFTESTS:;
  }
  bail_out(error);

  if (my_ID == root) {
    printf("Number of ranks      = %d\n", Num_procs);
    printf("Matrix order         = %d\n", order);
    printf("Number of iterations = %d\n", iterations);
    printf("Number of buffers    = %d\n", bufferCount);
    if ((Tile_order > 0) && (Tile_order < order))
          printf("Tile size            = %d\n", Tile_order);
    else  printf("Untiled\n");
  }
  
  shmem_barrier_all();

  /*  Broadcast input data to all ranks */
  shmem_broadcast32(&arguments[0], &arguments[0], 4, root, 0, 0, Num_procs, pSync_bcast);

  iterations=arguments[0];
  order=arguments[1];
  bufferCount=arguments[2];
  Tile_order=arguments[3];

  shmem_barrier_all();
  prk_shmem_free(arguments);

  /* a non-positive tile size means no tiling of the local transpose */
  tiling = (Tile_order > 0) && (Tile_order < order);
  bytes = 2 * sizeof(double) * order * order;

/*********************************************************************
** The matrix is broken up into column blocks that are mapped one to a 
** rank.  Each column block is made up of Num_procs smaller square 
** blocks of order block_order.
*********************************************************************/

  Block_order    = order/Num_procs;
  colstart       = Block_order * my_ID;
  Colblock_size  = order * Block_order;
  Block_size     = Block_order * Block_order;

/*********************************************************************
** Create the column block of the test matrix, the row block of the 
** transposed matrix, and workspace (workspace only if #procs>1)
*********************************************************************/
  A_p = (double *)prk_malloc(Colblock_size*sizeof(double));
  if (A_p == NULL){
    printf(" Error allocating space for original matrix on node %d\n",my_ID);
    error = 1;
  }
  bail_out(error);

  B_p = (double *)prk_malloc(Colblock_size*sizeof(double));
  if (B_p == NULL){
    printf(" Error allocating space for transpose matrix on node %d\n",my_ID);
    error = 1;
  }
  bail_out(error);

  if (Num_procs>1) {
    Work_in_p   = (double**)prk_malloc(bufferCount*sizeof(double));
    Work_out_p = (double *) prk_malloc(Block_size*sizeof(double));
    recv_flag  = (int*)     prk_shmem_align(prk_get_alignment(),bufferCount*sizeof(int));
    if ((Work_in_p == NULL)||(Work_out_p==NULL) || (recv_flag == NULL)){
      printf(" Error allocating space for work or flags on node %d\n",my_ID);
      error = 1;
    }

    if (bufferCount < (Num_procs - 1)) {
      send_flag = (int*) prk_shmem_align(prk_get_alignment(), (Num_procs-1) * sizeof(int));

      if (send_flag == NULL) {
	printf("Error allocating space for flags on node %d\n", my_ID);
	error = 1;
      }
    }

    bail_out(error);

    for(i=0;i<bufferCount;i++) {
      Work_in_p[i]=(double *) prk_shmem_align(prk_get_alignment(),Block_size*sizeof(double));
      if (Work_in_p[i] == NULL) {
        printf(" Error allocating space for work on node %d\n",my_ID);
        error = 1;
      }
      bail_out(error);
    }

    if (bufferCount < (Num_procs - 1)) {
      for(i=0;i<(Num_procs-1);i++)
        send_flag[i]=0;
    }

    for(i=0;i<bufferCount;i++)
      recv_flag[i]=0;
  }
  
  /* Fill the original column matrices                                              */
  istart = 0;  
  for (j=0;j<Block_order;j++) 
    for (i=0;i<order; i++)  {
      A(i,j) = (double) (order*(j+colstart) + i);
      B(i,j) = 0.0;
  }

  shmem_barrier_all();

  if (bufferCount < (Num_procs - 1)) {
    if (Num_procs > 1) {
      for ( i = 0; i < bufferCount; i++) {
        recv_from = (my_ID + i + 1)%Num_procs;
        shmem_int_inc(&send_flag[i], recv_from);
      }
    }
  }

  shmem_barrier_all();

  for (iter = 0; iter<=iterations; iter++){

    /* start timer after a warmup iteration                                        */
    if (iter == 1) { 
      shmem_barrier_all();
      local_trans_time[0] = wtime();
    }

    /* do the local transpose                                                     */
    istart = colstart; 
    if (!tiling) {
      for (i=0; i<Block_order; i++) 
        for (j=0; j<Block_order; j++) {
          B(j,i) += A(i,j);
          A(i,j) += 1.0;
	}
    }
    else {
      for (i=0; i<Block_order; i+=Tile_order) 
        for (j=0; j<Block_order; j+=Tile_order) 
          for (it=i; it<MIN(Block_order,i+Tile_order); it++)
            for (jt=j; jt<MIN(Block_order,j+Tile_order);jt++) {
              B(jt,it) += A(it,jt); 
              A(it,jt) += 1.0;
            }
    }

    for (phase=1; phase<Num_procs; phase++){
      recv_from = (my_ID + phase            )%Num_procs;
      send_to   = (my_ID - phase + Num_procs)%Num_procs;

      targetBuffer = (iter * (Num_procs - 1) + (phase - 1)) % bufferCount;

      istart = send_to*Block_order; 
      if (!tiling) {
        for (i=0; i<Block_order; i++) 
          for (j=0; j<Block_order; j++){
	    Work_out(j,i) = A(i,j);
            A(i,j) += 1.0;
	  }
      }
      else {
        for (i=0; i<Block_order; i+=Tile_order) 
          for (j=0; j<Block_order; j+=Tile_order) 
            for (it=i; it<MIN(Block_order,i+Tile_order); it++)
              for (jt=j; jt<MIN(Block_order,j+Tile_order);jt++) {
                Work_out(jt,it) = A(it,jt); 
                A(it,jt) += 1.0;
	      }
      }

      if (bufferCount < (Num_procs - 1))
        shmem_int_wait_until(&send_flag[phase-1], SHMEM_CMP_EQ, iter+1);

      shmem_double_put(&Work_in_p[targetBuffer][0], &Work_out_p[0], Block_size, send_to);
      shmem_fence();
      shmem_int_inc(&recv_flag[targetBuffer], send_to);

      i = (iter * (Num_procs - 1) + phase) / bufferCount;

      if ((iter * (Num_procs - 1) + phase) % bufferCount)
	i++;

      shmem_int_wait_until(&recv_flag[targetBuffer], SHMEM_CMP_EQ, i);

      istart = recv_from*Block_order; 
      /* scatter received block to transposed matrix; no need to tile */
      for (j=0; j<Block_order; j++)
        for (i=0; i<Block_order; i++) 
          B(i,j) += Work_in(targetBuffer, i,j);

      if (bufferCount < (Num_procs - 1)) {
        if ((phase + bufferCount) < Num_procs)
	  recv_from = (my_ID + phase + bufferCount) % Num_procs;
        else
	  recv_from = (my_ID + phase + bufferCount + 1 - Num_procs) % Num_procs;

        shmem_int_inc(&send_flag[(phase+bufferCount-1)%(Num_procs-1)], recv_from);
      }
    }  /* end of phase loop  */
  } /* end of iterations */

  local_trans_time[0] = wtime() - local_trans_time[0];

  shmem_barrier_all();
  shmem_double_max_to_all(trans_time, local_trans_time, 1, 0, 0, Num_procs, pWrk, pSync_reduce);

  abserr[0] = 0.0;
  istart = 0;
  double addit = ((double)(iterations+1) * (double) (iterations))/2.0;
  for (j=0;j<Block_order;j++) for (i=0;i<order; i++) {
      abserr[0] += ABS(B(i,j) - (double)((order*i + j+colstart)*(iterations+1)+addit));
  }

  shmem_barrier_all();
  shmem_double_sum_to_all(abserr_tot, abserr, 1, 0, 0, Num_procs, pWrk, pSync_reduce);

  if (my_ID == root) {
    if (abserr_tot[0] <= epsilon) {
      printf("Solution validates\n");
      avgtime = trans_time[0]/(double)iterations;
      printf("Rate (MB/s): %lf Avg time (s): %lf\n",1.0E-06*bytes/avgtime, avgtime);
#ifdef VERBOSE
      printf("Summed errors: %f \n", abserr[0]);
#endif
    }
    else {
      printf("ERROR: Aggregate squared error %e exceeds threshold %e\n", abserr[0], epsilon);
      error = 1;
    }
  }

  bail_out(error);

  if (Num_procs>1) 
  {
    if (bufferCount < (Num_procs - 1))
      prk_shmem_free(send_flag);

    prk_shmem_free(recv_flag);
    prk_free(Work_out_p);

    for(i=0;i<bufferCount;i++)
      prk_shmem_free(Work_in_p[i]);

    prk_free(Work_in_p);
  }

  prk_shmem_free(pSync_bcast);
  prk_shmem_free(pSync_reduce);
  prk_shmem_free(pWrk);

  prk_shmem_finalize();
  exit(EXIT_SUCCESS);

}  /* end of main */