program main
c This program calculates the variance of the first 10**9 integers
c using both cpus on the dual processor Macintosh.
c To compile with the Absoft Fortran compiler, use:
c f77 -O -Q92 adder.f MacMP.f "{SharedLibraries}"MPLibrary -o adder.out
      implicit none
      integer TickCount
      external TickCount
      integer NINT
      parameter (NINT=1000000000)
      integer n, n1, n2, start1, start2
      integer start_program, end_program
      double precision sum11, sum12, sum21, sum22, mean, mesq
      integer idtask, nproc, nargs
      external adder
      nargs = 4
      n = NINT
      n1 = NINT/2
      n2 = NINT
      start1 = 0
      start2 = n1
      start_program = TickCount()
      
      call MP_INIT(nproc)
c Use second cpu to compute partial sums for second group
      call MP_TASKSTART(idtask,adder,nargs,n2,start2,sum21,sum22)
c Use main cpu to compute partial sums for first group
      call adder(n1,start1,sum11,sum12)
c Wait for second cpu to complete
      call MP_TASKWAIT(idtask)
      call MP_END()

c Add partial sums together
      mean = (sum11 + sum21) / n
      mesq = (sum12 + sum22) / n

      write (*,'(i15,1x,f20.3,1x,f21.3)') n, mean, mesq - (mean * mean)

      end_program = TickCount()
      write (*,*)
      write (*,'("time in sec: ",f7.2)') (end_program-start_program)/60.
      write (*,*) 'hit carriage return to quit'
      pause
      stop
      end


      subroutine adder(n,start,s1,s2)
      integer n, start
      double precision s1, s2
      integer i
      double precision ls1, ls2
      ls1 = 0
      ls2 = 0
      do 10 i = start, n-1
      ls1 = ls1 + dble(i)
      ls2 = ls2 + dble(i)*i
   10 continue
      s1 = ls1
      s2 = ls2
      return
      end