! icbp : iso_c_binding for parpack

subroutine pssaupd_c(comm, ido, bmat, n, which, nev, tol, resid, ncv, v, ldv,&
                     iparam, ipntr, workd, workl, lworkl, info)              &
                     bind(c, name="pssaupd_c")
  use :: iso_c_binding
  implicit none
#include "arpackicb.h"
  integer(kind=i_int),    value,               intent(in)    :: comm
  integer(kind=i_int),                         intent(inout) :: ido
  character(kind=c_char), dimension(1),        intent(in)    :: bmat
  integer(kind=i_int),    value,               intent(in)    :: n
  character(kind=c_char), dimension(2),        intent(in)    :: which
  integer(kind=i_int),    value,               intent(in)    :: nev
  real(kind=c_float),     value,               intent(in)    :: tol
  real(kind=c_float),     dimension(n),        intent(inout) :: resid
  integer(kind=i_int),    value,               intent(in)    :: ncv
  real(kind=c_float),     dimension(ldv, ncv), intent(out)   :: v
  integer(kind=i_int),    value,               intent(in)    :: ldv
  integer(kind=i_int),    dimension(11),       intent(inout) :: iparam
  integer(kind=i_int),    dimension(11),       intent(out)   :: ipntr
  real(kind=c_float),     dimension(3*n),      intent(out)   :: workd
  real(kind=c_float),     dimension(lworkl),   intent(out)   :: workl
  integer(kind=i_int),    value,               intent(in)    :: lworkl
  integer(kind=i_int),                         intent(inout) :: info
  call pssaupd(comm, ido, bmat, n, which, nev, tol, resid, ncv, v, ldv,&
               iparam, ipntr, workd, workl, lworkl, info)
end subroutine pssaupd_c

subroutine psseupd_c(comm, rvec, howmny, select, d, z, ldz, sigma,&
                     bmat, n, which, nev, tol, resid, ncv, v, ldv,&
                     iparam, ipntr, workd, workl, lworkl, info)   &
                     bind(c, name="psseupd_c")
  use :: iso_c_binding
  implicit none
#include "arpackicb.h"
  integer(kind=i_int),    value,               intent(in)    :: comm
  integer(kind=i_int),    value,               intent(in)    :: rvec
  character(kind=c_char), dimension(1),        intent(in)    :: howmny
  integer(kind=i_int),    dimension(ncv),      intent(in)    :: select
  real(kind=c_float),     dimension(nev),      intent(out)   :: d
  real(kind=c_float),     dimension(n, nev),   intent(out)   :: z
  integer(kind=i_int),    value,               intent(in)    :: ldz
  real(kind=c_float),     value,               intent(in)    :: sigma
  character(kind=c_char), dimension(1),        intent(in)    :: bmat
  integer(kind=i_int),    value,               intent(in)    :: n
  character(kind=c_char), dimension(2),        intent(in)    :: which
  integer(kind=i_int),    value,               intent(in)    :: nev
  real(kind=c_float),     value,               intent(in)    :: tol
  real(kind=c_float),     dimension(n),        intent(inout) :: resid
  integer(kind=i_int),    value,               intent(in)    :: ncv
  real(kind=c_float),     dimension(ldv, ncv), intent(out)   :: v
  integer(kind=i_int),    value,               intent(in)    :: ldv
  integer(kind=i_int),    dimension(7),        intent(inout) :: iparam
  integer(kind=i_int),    dimension(11),       intent(out)   :: ipntr
  real(kind=c_float),     dimension(3*n),      intent(out)   :: workd
  real(kind=c_float),     dimension(lworkl),   intent(out)   :: workl
  integer(kind=i_int),    value,               intent(in)    :: lworkl
  integer(kind=i_int),                         intent(inout) :: info

  ! convert parameters if needed.

  logical :: rv
  logical, dimension(ncv) :: slt
  integer :: idx

  rv = .false.
  if (rvec .ne. 0) rv = .true.

  slt = .false.
  do idx=1, ncv
    if (select(idx) .ne. 0) slt(idx) = .true.
  enddo

  ! call arpack.

  call psseupd(comm, rv, howmny, slt, d, z, ldz, sigma,     &
               bmat, n, which, nev, tol, resid, ncv, v, ldv,&
               iparam, ipntr, workd, workl, lworkl, info)
end subroutine psseupd_c