sym7pol.f

来自「网络带宽测试工具」· F 代码 · 共 42 行

      Subroutine sym7pol( n1, n2, n3, m, a, rmr, q, x, y, gamma )
! ---------------------------------------------------------------------
! --- Polynomial (Neumann) preconditioner.
! ---------------------------------------------------------------------
      Use         numerics
      Use         floptime
      Implicit    None

      Integer  :: n1, n2, n3, m
      Real(l_) :: a(n1*n2*n3,0:3), rmr, q(n1*n2*n3), x(n1*n2*n3),
     &            y(n1*n2*n3)
      Real(l_) :: gamma(m+1)
      Real(l_) :: nrm2

      Real(l_) :: t(n1*n2*n3), w(n1*n2*n3)
      Integer  :: i, j, n12, ntot
! ---------------------------------------------------------------------
      n12  = n1*n2
      ntot = n12*n3
!$omp parallel do
      Do j = 1, ntot
         t(j) = q(j)*x(j)
         y(j) = t(j)
         y(j) = gamma(m+1)*y(j)
      End Do
      Do i = 1, m
         Call sym7mxv( n1, n2, n3, a, y, w )
!$omp parallel do
         Do j = 1, ntot
            w(j) = q(j)*w(j)
            y(j) = y(j) - w(j)
            y(j) = y(j) + gamma(m-i+1)*t(j)
         End Do
      End Do
! ---------------------------------------------------------------------
! --- Computation of (r,Mr) where M is the preconditioner.

      rmr = nrm2( ntot, y )
      flops = flops + ntot*( 2 + 4*m )
! ---------------------------------------------------------------------
      End Subroutine sym7pol