subroutine radf5(ido, l1, cc, ch, wa1, wa2, wa3, wa4)
use fftpack_kind, only: dp => rk
implicit none
integer, intent(in) :: ido, l1
real(dp), intent(in) :: cc(ido, l1, 5), wa1(*), wa2(*), wa3(*), wa4(*)
real(dp), intent(out) :: ch(ido, 5, l1)
real(dp) :: ci2, ci3, ci4, ci5, cr2, cr3, &
cr4, cr5, di2, di3, di4, di5, dr2, dr3, &
dr4, dr5
real(dp) :: ti2, ti3, ti4, ti5, tr2, tr3, &
tr4, tr5
integer :: i, ic, idp2, k
real(dp), parameter :: pi = acos(-1.0_dp)
real(dp), parameter :: tr11 = cos(2.0_dp*pi/5.0_dp)
real(dp), parameter :: ti11 = sin(2.0_dp*pi/5.0_dp)
real(dp), parameter :: tr12 = cos(4.0_dp*pi/5.0_dp)
real(dp), parameter :: ti12 = sin(4.0_dp*pi/5.0_dp)
do k = 1, l1
cr2 = cc(1, k, 5) + cc(1, k, 2)
ci5 = cc(1, k, 5) - cc(1, k, 2)
cr3 = cc(1, k, 4) + cc(1, k, 3)
ci4 = cc(1, k, 4) - cc(1, k, 3)
ch(1, 1, k) = cc(1, k, 1) + cr2 + cr3
ch(ido, 2, k) = cc(1, k, 1) + tr11*cr2 + tr12*cr3
ch(1, 3, k) = ti11*ci5 + ti12*ci4
ch(ido, 4, k) = cc(1, k, 1) + tr12*cr2 + tr11*cr3
ch(1, 5, k) = ti12*ci5 - ti11*ci4
end do
if (ido == 1) return
idp2 = ido + 2
do k = 1, l1
do i = 3, ido, 2
ic = idp2 - i
dr2 = wa1(i - 2)*cc(i - 1, k, 2) + wa1(i - 1)*cc(i, k, 2)
di2 = wa1(i - 2)*cc(i, k, 2) - wa1(i - 1)*cc(i - 1, k, 2)
dr3 = wa2(i - 2)*cc(i - 1, k, 3) + wa2(i - 1)*cc(i, k, 3)
di3 = wa2(i - 2)*cc(i, k, 3) - wa2(i - 1)*cc(i - 1, k, 3)
dr4 = wa3(i - 2)*cc(i - 1, k, 4) + wa3(i - 1)*cc(i, k, 4)
di4 = wa3(i - 2)*cc(i, k, 4) - wa3(i - 1)*cc(i - 1, k, 4)
dr5 = wa4(i - 2)*cc(i - 1, k, 5) + wa4(i - 1)*cc(i, k, 5)
di5 = wa4(i - 2)*cc(i, k, 5) - wa4(i - 1)*cc(i - 1, k, 5)
cr2 = dr2 + dr5
ci5 = dr5 - dr2
cr5 = di2 - di5
ci2 = di2 + di5
cr3 = dr3 + dr4
ci4 = dr4 - dr3
cr4 = di3 - di4
ci3 = di3 + di4
ch(i - 1, 1, k) = cc(i - 1, k, 1) + cr2 + cr3
ch(i, 1, k) = cc(i, k, 1) + ci2 + ci3
tr2 = cc(i - 1, k, 1) + tr11*cr2 + tr12*cr3
ti2 = cc(i, k, 1) + tr11*ci2 + tr12*ci3
tr3 = cc(i - 1, k, 1) + tr12*cr2 + tr11*cr3
ti3 = cc(i, k, 1) + tr12*ci2 + tr11*ci3
tr5 = ti11*cr5 + ti12*cr4
ti5 = ti11*ci5 + ti12*ci4
tr4 = ti12*cr5 - ti11*cr4
ti4 = ti12*ci5 - ti11*ci4
ch(i - 1, 3, k) = tr2 + tr5
ch(ic - 1, 2, k) = tr2 - tr5
ch(i, 3, k) = ti2 + ti5
ch(ic, 2, k) = ti5 - ti2
ch(i - 1, 5, k) = tr3 + tr4
ch(ic - 1, 4, k) = tr3 - tr4
ch(i, 5, k) = ti3 + ti4
ch(ic, 4, k) = ti4 - ti3
end do
end do
end subroutine radf5
