/*
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
c
c   s7 generates my chunk of the pseudo-random A stream for Benchmark #7
c      single-cpu version does whole stream from 0 to numbufs-1
c
c   Parameters:
c     Provided by calling routine:
c      fd     =  file descriptor for temp file
c      myfirst=  first bufnum for my PE to generate
c      mylast =  last bufnum for my PE to generate
c      seed   =  Seed for randon number generator
c      A      =  Array in which to generate the data, a buffer at a time
c
c   If fd >= 0, then total numbufs>1, write the data to disk
c   If fd <  0, then total numbufs=1, return the data in array A
c
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
*/
#include "bench7.h"

s7 ( int fd, uint64 * A, int myfirst, int mylast, int seed )
{
   // A[2][BUFSIZE] in main, but S7 just uses the 0th buffer
   // so ignore the global shape.

   uint64 PAT1010 = 0XAAAAAAAAAAAAAAAA,
	  PAT0101 = 0X5555555555555555;

   int64 nwds = BUFSIZE;
   int64 negseed = -(long)seed;
   int bufnum;
   int64 myf=0, myl=0;  /* dummy */
   int i, i1, i2;

// generate a buffer-full at a time and write to disk

   for ( bufnum = myfirst; bufnum <= mylast; bufnum++ )
   {
      // bufnum+1 to get same data as Fortran

      get_my_bdata64( bufnum+1, 1, 1, nwds, 1, negseed, A, &myf, &myl );

      // Artificially insert several regions that produce
      //   600-long patterns in the B and C streams and thence
      //   500-long runs of zeros in E-stream

      for ( i = -1; i <= 19; i++ )
      {
         A[ i + 68750  ] = PAT1010;
         A[ i + 78776  ] = PAT0101;
         A[ i + 137500 ] = 0;
         A[ i + 157552 ] = -1;
      }

      //  Create a zero region overlapping end of buff i and start of buff i+1
      //  Region at end of buff is not long enough w/o beginning of next buff
      //  So no trouble checking results: we get 5 regions in each buffer
      //   except the last one, which has 4 regions
      i1 = 4;
      i2 = 6;
      for (i=1; i<=i1; i++)
         A[nwds-i] = 0;
      if (bufnum > 0)
         for (i=0; i<i2; i++)
            A[i] = 0;

      if (fd >= 0)  // if tot numbufs==1, fd has init val -1
      {
         wrtmp(fd, A, nwds);
         syntmp(fd);
      }
   }

   return;
}