program fake_adi
      implicit none
      integer ldx, ldy, ldz, nx, ny, nz, maxsteps
      parameter (ldx = 128, ldy = 128, ldz = 128)
      parameter (nx = 128, ny = 128, nz = 128)
      parameter (maxsteps = 2)
      real*8 data(ldx,ldy,ldz)
      integer i, j, k, istep
      external rand, dtime
      real*4 dtime, t, t2(2)
      real*8 rand, checksum
c
      do k =1,nz
         do j =1,ny
            do i =1,nx
               data(i,j,k) = rand()
            enddo
         enddo
      enddo
c
      t = dtime(t2)
c
      do istep = 1, maxsteps
c
c*$* assert concurrent call
      do k =1,nz
         do j =1,ny
            call xsweep(data(1,j,k),1,nx)
         enddo
      enddo
c
c*$* assert concurrent call
      do k =1,nz
         do i =1,nx
            call ysweep(data(i,1,k),ldx,ny)
         enddo
      enddo
c
c*$* assert concurrent call
      do j =1,ny
         do i =1,nx
            call zsweep(data(i,j,1),ldx*ldy,nz)
         enddo
      enddo
c
      enddo
c
      t = dtime(t2)
      write(6,1) t
    1 format(1x,'Time: ',f6.3,' seconds')
      checksum = 0.0d0
      do k =1,nz
         do j =1,ny
            do i =1,nx
               checksum = checksum + data(i,j,k)
            enddo
         enddo
      enddo
c
      write(6,2) checksum
    2 format(1x,'Checksum: ',1pe17.10)
c
      end
c---------------------------------------------------------------------
      subroutine xsweep(v,is,n)
      implicit none
      real*8 v(1+is*(n-1))
      integer is, n
      integer i
      real*8 half
      parameter (half = 0.5d0)
c
      do i =2,n
         v(1+is*(i-1)) = v(1+is*(i-1)) + half*v(1+is*(i-2))
      enddo
c
      do i = n-1, 1, -1
         v(1+is*(i-1)) = v(1+is*(i-1)) - half*v(1+is*i)
      enddo
c
      return
      end
c---------------------------------------------------------------------
      subroutine ysweep(v,is,n)
      implicit none
      real*8 v(1+is*(n-1))
      integer is, n
      integer i
      real*8 half
      parameter (half = 0.5d0)
c
      do i =2,n
         v(1+is*(i-1)) = v(1+is*(i-1)) + half*v(1+is*(i-2))
      enddo
c
      do i = n-1, 1, -1
         v(1+is*(i-1)) = v(1+is*(i-1)) - half*v(1+is*i)
      enddo
c
      return
      end
c---------------------------------------------------------------------
      subroutine zsweep(v,is,n)
      implicit none
      real*8 v(1+is*(n-1))
      integer is, n
      integer i
      real*8 half
      parameter (half = 0.5d0)
c
      do i =2,n
         v(1+is*(i-1)) = v(1+is*(i-1)) + half*v(1+is*(i-2))
      enddo
c
      do i = n-1, 1, -1
         v(1+is*(i-1)) = v(1+is*(i-1)) - half*v(1+is*i)
      enddo
c
      return
      end