! File: fft27t.i90
! Public domain 2004 James Van Buskirk
subroutine fft27t(h)
! 380 adds, 124 muls
   complex(wp), intent(inout) :: h(0:26)
   real(wp) xr1, xi1, xr2, xi2, xr3, xi3, xr4, xi4, xr5, xi5
   real(wp) xr6, xi6, xr7, xi7, xr8, xi8, xr9, xi9, xra, xia
   real(wp) xrb, xib, xrc, xic, xrd, xid, xre, xie
   real(wp) yr1, yi1, yr2, yi2, yr3, yi3, yr4, yi4, yr5, yi5
   real(wp) yr6, yi6, yr7, yi7, yr8, yi8, yr9, yi9, yra, yia
   real(wp) yrb, yib, yrc, yic, yrd, yid
   real(wp) xr3a, xi3a, xr3_a, xi3_a
   real(wp) xr94, xi94, xr9_4, xi9_4
   real(wp) xr67, xi67, xr6_7, xi6_7
   real(wp) xr58, xi58, xr5_8, xi5_8
   real(wp) yr29, yi29, yr2_9, yi2_9
   real(wp) yr83, yi83, yr8_3, yi8_3
   real(wp) yr56, yi56, yr5_6, yi5_6
   real(wp) yr47, yi47, yr4_7, yi4_7
   real(wp) xr396a47, xi396a47, xr258, xi258, pr142, pi142
   real(wp) pr0, pi0, pr1, pi1, pr4, pi4, pr2, pi2, pr3, pi3
   real(wp) pr7, pi7, pr586, pi586
   real(wp) pr5, pi5, pr8, pi8, pr6, pi6
   real(wp) yr285936, yi285936, yr147, yi147, qr142, qi142
   real(wp) qr0, qi0, qr1, qi1, qr4, qi4, qr2, qi2, qr3, qi3
   real(wp) qr7, qi7, qr586, qi586
   real(wp) qr5, qi5, qr8, qi8, qr6, qi6
   real(wp) xrbcd, xibcd, xr1e, xi1e
   real(wp) sr1e, si1e, sr1, si1, sre, sie
   real(wp) ur2, ui2, ur5, ui5, ur8, ui8
   real(wp) ur3, ui3, ur4, ui4, ur6, ui6
   real(wp) ur7, ui7, ur9, ui9, ura, uia
   real(wp) urb, uib, urc, uic, urd, uid
   real(wp) srb, sib, src, sic, srd, sid
   real(wp) sr2, si2, sr3, si3, sr4, si4
   real(wp) sr5, si5, sr6, si6, sr7, si7
   real(wp) sr8, si8, sr9, si9, sra, sia
   real(wp) yrabc, yiabc
   real(wp) trd, tid
   real(wp) vr1, vi1, vr4, vi4, vr7, vi7
   real(wp) vr2, vi2, vr3, vi3, vr5, vi5
   real(wp) vr6, vi6, vr8, vi8, vr9, vi9
   real(wp) vra, via, vrb, vib, vrc, vic
   real(wp) tra, tia, trb, tib, trc, tic
   real(wp) tr1, ti1, tr2, ti2, tr3, ti3
   real(wp)  tr4, ti4, tr5, ti5, tr6, ti6
   real(wp) tr7, ti7, tr8, ti8, tr9, ti9
   real(wp) xr3a_94, xi3a_94, xr94_67, xi94_67
   real(wp) pr1_4, pi1_4, pr4_2, pi4_2
   real(wp) xr34_9a, xi34_9a, xr79_46, xi79_46
   real(wp) pr5_8, pi5_8, pr8_6, pi8_6
   real(wp) xrb_c, xib_c, xrc_d, xic_d
   real(wp) sr258, si258, sr2_5, si2_5, sr5_8, si5_8
   real(wp) yr29_83, yi29_83, yr83_56, yi83_56
   real(wp) qr1_4, qi1_4, qr4_2, qi4_2
   real(wp) yr23_89, yi23_89, yr68_35, yi68_35
   real(wp) qr5_8, qi5_8, qr8_6, qi8_6
   real(wp) yra_b, yia_b, yrb_c, yib_c
   real(wp) tr147, ti147, tr1_4, ti1_4, tr4_7, ti4_7
   real(wp), parameter :: half = 0.50000000000000000000000000000000000_wp
   real(wp), parameter :: dc1 = 0.74539561601309920652221317372530749_wp
   real(wp), parameter :: dc2 = -0.14823702431031304167036101314134772_wp
   real(wp), parameter :: dc3 = 0.21970402268688979797889138920491935_wp
   real(wp), parameter :: dc4 = -0.61578378872604662167493478081466396_wp
   real(wp), parameter :: dc5 = 0.45745002083467400514706857796881122_wp
   real(wp), parameter :: dc6 = -0.51559484974514983368581659481588413_wp
   real(wp), parameter :: dc7 = -0.30341470380616099754464700684974935_wp
   real(wp), parameter :: dc8 = -0.59021793651725125064792718001690654_wp
   real(wp), parameter :: dc9 = -4.4541523082973710438876419516790012E-0002_wp
   real(wp), parameter :: dc10 = -0.64170011478575987529072858010074892_wp
   real(wp), parameter :: dc11 = -0.68456231830949033126446428219722059_wp
   real(wp), parameter :: dc12 = -0.28848255227033350756842089058747534_wp
   real(wp), parameter :: dc13 = 0.76604444311897803520239265055541666_wp
   real(wp), parameter :: dc14 = -0.17364817766693034885171662676931448_wp
   real(wp), parameter :: dc15 = -0.93969262078590838405410927732473123_wp
   real(wp), parameter :: dc16 = -0.55667039922641936645291295204702315_wp
   real(wp), parameter :: dc17 = -0.85286853195244320962825096394007399_wp
   real(wp), parameter :: r3 = 0.86602540378443864676372317075293616_wp
   real(wp), parameter :: ds1 = 0.17666200627729080614912727860039091_wp
   real(wp), parameter :: ds2 = 0.62546118647775297893416761333353415_wp
   real(wp), parameter :: ds3 = 0.73386254247554002501087089468238537_wp
   real(wp), parameter :: ds4 = 0.18435356440473398974809052063225121_wp
   real(wp), parameter :: ds5 = 0.61446201450685419324900952903810861_wp
   real(wp), parameter :: ds6 = 0.38384614376441401479881117974516886_wp
   real(wp), parameter :: ds7 = 0.70339434625797552361120755084494837_wp
   real(wp), parameter :: ds8 = -0.25459516605751335082616721611180600_wp
   real(wp), parameter :: ds9 = 0.76474841716404624053523565479886999_wp
   real(wp), parameter :: ds10 = -3.7374775590997544548059237135055261E-0002_wp
   real(wp), parameter :: ds11 = 0.34380011806891691815438153301084783_wp
   real(wp), parameter :: ds12 = -0.57441598881135709660457988230378796_wp
   real(wp), parameter :: ds13 = 0.64278760968653932632264340990726338_wp
   real(wp), parameter :: ds14 = 0.98480775301220805936674302458952306_wp
   real(wp), parameter :: ds15 = 0.34202014332566873304409961468225968_wp
   real(wp), parameter :: ds16 = 0.66341394816893839620542131963589127_wp
   real(wp), parameter :: ds17 = -0.15038373318043529663927189761250221_wp
   real(wp), parameter :: cc1 = 0.22668159690567746581165180818809266_wp
   real(wp), parameter :: cc2 = -1.2266815969056774658116518081880926_wp
   real(wp), parameter :: cc3 = 1.3054072893322786045931334929227409_wp
   real(wp), parameter :: cc4 = -0.65270364466613930229656674646137046_wp
   real(wp), parameter :: cs1 = 0.53208888623795607040478530111083360_wp
   real(wp), parameter :: cs2 = -1.5320888862379560704047853011108335_wp
   real(wp), parameter :: cs3 = 1.3472963553338606977034332535386297_wp
   xr1 = real(h(0))
   xi1 = aimag(h(0))
   xr2 = real(h(1))+real(h(26))
   xi2 = aimag(h(1))+aimag(h(26))
   xr3 = real(h(4))+real(h(23))
   xi3 = aimag(h(4))+aimag(h(23))
   xr4 = real(h(7))+real(h(20))
   xi4 = aimag(h(7))+aimag(h(20))
   xr5 = real(h(10))+real(h(17))
   xi5 = aimag(h(10))+aimag(h(17))
   xr6 = real(h(13))+real(h(14))
   xi6 = aimag(h(13))+aimag(h(14))
   xr7 = real(h(16))+real(h(11))
   xi7 = aimag(h(16))+aimag(h(11))
   xr8 = real(h(19))+real(h(8))
   xi8 = aimag(h(19))+aimag(h(8))
   xr9 = real(h(22))+real(h(5))
   xi9 = aimag(h(22))+aimag(h(5))
   xra = real(h(25))+real(h(2))
   xia = aimag(h(25))+aimag(h(2))
   xrb = real(h(3))+real(h(24))
   xib = aimag(h(3))+aimag(h(24))
   xrc = real(h(12))+real(h(15))
   xic = aimag(h(12))+aimag(h(15))
   xrd = real(h(21))+real(h(6))
   xid = aimag(h(21))+aimag(h(6))
   xre = real(h(9))+real(h(18))
   xie = aimag(h(9))+aimag(h(18))
   yr1 = real(h(1))-real(h(26))
   yi1 = aimag(h(1))-aimag(h(26))
   yr2 = real(h(4))-real(h(23))
   yi2 = aimag(h(4))-aimag(h(23))
   yr3 = real(h(7))-real(h(20))
   yi3 = aimag(h(7))-aimag(h(20))
   yr4 = real(h(10))-real(h(17))
   yi4 = aimag(h(10))-aimag(h(17))
   yr5 = real(h(13))-real(h(14))
   yi5 = aimag(h(13))-aimag(h(14))
   yr6 = real(h(16))-real(h(11))
   yi6 = aimag(h(16))-aimag(h(11))
   yr7 = real(h(19))-real(h(8))
   yi7 = aimag(h(19))-aimag(h(8))
   yr8 = real(h(22))-real(h(5))
   yi8 = aimag(h(22))-aimag(h(5))
   yr9 = real(h(25))-real(h(2))
   yi9 = aimag(h(25))-aimag(h(2))
   yra = real(h(3))-real(h(24))
   yia = aimag(h(3))-aimag(h(24))
   yrb = real(h(12))-real(h(15))
   yib = aimag(h(12))-aimag(h(15))
   yrc = real(h(21))-real(h(6))
   yic = aimag(h(21))-aimag(h(6))
   yrd = real(h(9))-real(h(18))
   yid = aimag(h(9))-aimag(h(18))
   xr3a = xr3+xra
   xi3a = xi3+xia
   xr3_a = xr3-xra
   xi3_a = xi3-xia
   xr94 = xr9+xr4
   xi94 = xi9+xi4
   xr9_4 = xr9-xr4
   xi9_4 = xi9-xi4
   xr67 = xr6+xr7
   xi67 = xi6+xi7
   xr6_7 = xr6-xr7
   xi6_7 = xi6-xi7
   xr58 = xr5+xr8
   xi58 = xi5+xi8
   xr5_8 = xr5-xr8
   xi5_8 = xi5-xi8
   xr396a47 = xr3a+xr94+xr67
   xi396a47 = xi3a+xi94+xi67
   xr258 = xr2+xr58
   xi258 = xi2+xi58
   xr3a_94 = xr3a-xr94
   xi3a_94 = xi3a-xi94
   xr94_67 = xr94-xr67
   xi94_67 = xi94-xi67
   pr1_4 = xr3a_94-cc2*xr94_67
   pi1_4 = xi3a_94-cc2*xi94_67
   pr4_2 = xr94_67-cc1*xr3a_94
   pi4_2 = xi94_67-cc1*xi3a_94
   pr142 = cc3*xr2+cc4*xr58
   pi142 = cc3*xi2+cc4*xi58
   pr0 = xr258+xr396a47
   pi0 = xi258+xi396a47
   pr1 = pr142+pr1_4
   pi1 = pi142+pi1_4
   pr4 = pr142-pr1_4+pr4_2
   pi4 = pi142-pi1_4+pi4_2
   pr2 = pr142-pr4_2
   pi2 = pi142-pi4_2
   pr3 = xr258-half*xr396a47
   pi3 = xi258-half*xi396a47
   pr7 = xr3_a+xr9_4+xr6_7
   pi7 = xi3_a+xi9_4+xi6_7
   pr586 = cs3*xr5_8
   pi586 = cs3*xi5_8
   xr34_9a = xr3_a-xr9_4
   xi34_9a = xi3_a-xi9_4
   xr79_46 = xr9_4-xr6_7
   xi79_46 = xi9_4-xi6_7
   pr5_8 = xr34_9a-cs1*xr79_46
   pi5_8 = xi34_9a-cs1*xi79_46
   pr8_6 = xr79_46-cs2*xr34_9a
   pi8_6 = xi79_46-cs2*xi34_9a
   pr5 = pr586+pr5_8
   pi5 = pi586+pi5_8
   pr8 = pr586-pr5_8+pr8_6
   pi8 = pi586-pi5_8+pi8_6
   pr6 = pr586-pr8_6
   pi6 = pi586-pi8_6
   xrbcd = xrb+xrc+xrd
   xibcd = xib+xic+xid
   xrb_c = xrb-xrc
   xib_c = xib-xic
   xrc_d = xrc-xrd
   xic_d = xic-xid
   xr1e = xr1+xre
   xi1e = xi1+xie
   ur2 = xr1-half*xre
   ui2 = xi1-half*xie
   sr1e = xr1e+xrbcd
   si1e = xi1e+xibcd
   sr1 = sr1e+pr0
   si1 = si1e+pi0
   sre = sr1e-half*pr0
   sie = si1e-half*pi0
   ur5 = dc13*xrb_c+dc14*xrc_d
   ui5 = dc13*xib_c+dc14*xic_d
   ur8 = dc14*xrb_c+dc15*xrc_d
   ui8 = dc14*xib_c+dc15*xic_d
   ur3 = dc1*pr1+dc2*pr5
   ui3 = dc1*pi1+dc2*pi5
   ur4 = dc3*pr1+dc4*pr5
   ui4 = dc3*pi1+dc4*pi5
   ur6 = dc5*pr4+dc6*pr8
   ui6 = dc5*pi4+dc6*pi8
   ur7 = dc7*pr4+dc8*pr8
   ui7 = dc7*pi4+dc8*pi8
   ur9 = dc9*pr2+dc10*pr6
   ui9 = dc9*pi2+dc10*pi6
   ura = dc11*pr2+dc12*pr6
   uia = dc11*pi2+dc12*pi6
   urb = xr1e-half*xrbcd
   uib = xi1e-half*xibcd
   urc = dc13*pr3+dc16*pr7
   uic = dc13*pi3+dc16*pi7
   urd = dc14*pr3+dc17*pr7
   uid = dc14*pi3+dc17*pi7
   sr258 = ur2+ur5
   si258 = ui2+ui5
   sr2_5 = ur2-ur5+ur8
   si2_5 = ui2-ui5+ui8
   sr5_8 = ur2-ur8
   si5_8 = ui2-ui8
   sr2 = sr258+ur3
   si2 = si258+ui3
   sr3 = sr258-ur3+ur4
   si3 = si258-ui3+ui4
   sr4 = sr258-ur4
   si4 = si258-ui4
   sr5 = sr2_5+ur6
   si5 = si2_5+ui6
   sr6 = sr2_5-ur6+ur7
   si6 = si2_5-ui6+ui7
   sr7 = sr2_5-ur7
   si7 = si2_5-ui7
   sr8 = sr5_8+ur9
   si8 = si5_8+ui9
   sr9 = sr5_8-ur9+ura
   si9 = si5_8-ui9+uia
   sra = sr5_8-ura
   sia = si5_8-uia
   srb = urb+urc
   sib = uib+uic
   src = urb-urc+urd
   sic = uib-uic+uid
   srd = urb-urd
   sid = uib-uid

   yr29 = yr2+yr9
   yi29 = yi2+yi9
   yr2_9 = yr2-yr9
   yi2_9 = yi2-yi9
   yr83 = yr8+yr3
   yi83 = yi8+yi3
   yr8_3 = yr8-yr3
   yi8_3 = yi8-yi3
   yr56 = yr5+yr6
   yi56 = yi5+yi6
   yr5_6 = yr5-yr6
   yi5_6 = yi5-yi6
   yr47 = yr4+yr7
   yi47 = yi4+yi7
   yr4_7 = yr4-yr7
   yi4_7 = yi4-yi7
   yr285936 = yr29+yr83+yr56
   yi285936 = yi29+yi83+yi56
   yr147 = yr1+yr47
   yi147 = yi1+yi47
   yr29_83 = yr29-yr83
   yi29_83 = yi29-yi83
   yr83_56 = yr83-yr56
   yi83_56 = yi83-yi56
   qr1_4 = yr29_83-cc2*yr83_56
   qi1_4 = yi29_83-cc2*yi83_56
   qr4_2 = yr83_56-cc1*yr29_83
   qi4_2 = yi83_56-cc1*yi29_83
   qr142 = cc3*yr1+cc4*yr47
   qi142 = cc3*yi1+cc4*yi47
   qr0 = yr147+yr285936
   qi0 = yi147+yi285936
   qr1 = qr142+qr1_4
   qi1 = qi142+qi1_4
   qr4 = qr142-qr1_4+qr4_2
   qi4 = qi142-qi1_4+qi4_2
   qr2 = qr142-qr4_2
   qi2 = qi142-qi4_2
   qr3 = yr147-half*yr285936
   qi3 = yi147-half*yi285936
   qr7 = yr2_9+yr8_3+yr5_6
   qi7 = yi2_9+yi8_3+yi5_6
   qr586 = cs3*yr4_7
   qi586 = cs3*yi4_7
   yr23_89 = yr2_9-yr8_3
   yi23_89 = yi2_9-yi8_3
   yr68_35 = yr8_3-yr5_6
   yi68_35 = yi8_3-yi5_6
   qr5_8 = yr23_89-cs1*yr68_35
   qi5_8 = yi23_89-cs1*yi68_35
   qr8_6 = yr68_35-cs2*yr23_89
   qi8_6 = yi68_35-cs2*yi23_89
   qr5 = qr586+qr5_8
   qi5 = qi586+qi5_8
   qr8 = qr586-qr5_8+qr8_6
   qi8 = qi586-qi5_8+qi8_6
   qr6 = qr586-qr8_6
   qi6 = qi586-qi8_6
   yrabc = yra+yrb+yrc
   yiabc = yia+yib+yic
   yra_b = yra-yrb
   yia_b = yia-yib
   yrb_c = yrb-yrc
   yib_c = yib-yic
   vr1 = r3*yrd
   vi1 = r3*yid
   trd = r3*qr0
   tid = r3*qi0
   vr4 = ds13*yra_b+ds14*yrb_c
   vi4 = ds13*yia_b+ds14*yib_c
   vr7 = ds14*yra_b+ds15*yrb_c
   vi7 = ds14*yia_b+ds15*yib_c
   vr2 = ds1*qr1+ds2*qr5
   vi2 = ds1*qi1+ds2*qi5
   vr3 = ds3*qr1+ds4*qr5
   vi3 = ds3*qi1+ds4*qi5
   vr5 = ds5*qr4+ds6*qr8
   vi5 = ds5*qi4+ds6*qi8
   vr6 = ds7*qr4+ds8*qr8
   vi6 = ds7*qi4+ds8*qi8
   vr8 = ds9*qr2+ds10*qr6
   vi8 = ds9*qi2+ds10*qi6
   vr9 = ds11*qr2+ds12*qr6
   vi9 = ds11*qi2+ds12*qi6
   vra = r3*yrabc
   via = r3*yiabc
   vrb = ds13*qr3+ds16*qr7
   vib = ds13*qi3+ds16*qi7
   vrc = ds14*qr3+ds17*qr7
   vic = ds14*qi3+ds17*qi7
   tr147 = vr1+vr4
   ti147 = vi1+vi4
   tr1_4 = vr1-vr4+vr7
   ti1_4 = vi1-vi4+vi7
   tr4_7 = vr1-vr7
   ti4_7 = vi1-vi7
   tr1 = tr147+vr2
   ti1 = ti147+vi2
   tr2 = tr147-vr2+vr3
   ti2 = ti147-vi2+vi3
   tr3 = tr147-vr3
   ti3 = ti147-vi3
   tr4 = tr1_4+vr5
   ti4 = ti1_4+vi5
   tr5 = tr1_4-vr5+vr6
   ti5 = ti1_4-vi5+vi6
   tr6 = tr1_4-vr6
   ti6 = ti1_4-vi6
   tr7 = tr4_7+vr8
   ti7 = ti4_7+vi8
   tr8 = tr4_7-vr8+vr9
   ti8 = ti4_7-vi8+vi9
   tr9 = tr4_7-vr9
   ti9 = ti4_7-vi9
   tra = vra+vrb
   tia = via+vib
   trb = vra-vrb+vrc
   tib = via-vib+vic
   trc = vra-vrc
   tic = via-vic

   h(0) = cmplx(sr1,si1,wp)
   h(1) = cmplx(sr2+ti1,si2-tr1,wp)
   h(2) = cmplx(sra-ti9,sia+tr9,wp)
   h(3) = cmplx(srb+tia,sib-tra,wp)
   h(4) = cmplx(sr5+ti4,si5-tr4,wp)
   h(5) = cmplx(sr7-ti6,si7+tr6,wp)
   h(6) = cmplx(srd-tic,sid+trc,wp)
   h(7) = cmplx(sr8+ti7,si8-tr7,wp)
   h(8) = cmplx(sr4-ti3,si4+tr3,wp)
   h(9) = cmplx(sre+tid,sie-trd,wp)
   h(10) = cmplx(sr3+ti2,si3-tr2,wp)
   h(11) = cmplx(sr9-ti8,si9+tr8,wp)
   h(12) = cmplx(src+tib,sic-trb,wp)
   h(13) = cmplx(sr6+ti5,si6-tr5,wp)
   h(14) = cmplx(sr6-ti5,si6+tr5,wp)
   h(15) = cmplx(src-tib,sic+trb,wp)
   h(16) = cmplx(sr9+ti8,si9-tr8,wp)
   h(17) = cmplx(sr3-ti2,si3+tr2,wp)
   h(18) = cmplx(sre-tid,sie+trd,wp)
   h(19) = cmplx(sr4+ti3,si4-tr3,wp)
   h(20) = cmplx(sr8-ti7,si8+tr7,wp)
   h(21) = cmplx(srd+tic,sid-trc,wp)
   h(22) = cmplx(sr7+ti6,si7-tr6,wp)
   h(23) = cmplx(sr5-ti4,si5+tr4,wp)
   h(24) = cmplx(srb-tia,sib+tra,wp)
   h(25) = cmplx(sra+ti9,sia-tr9,wp)
   h(26) = cmplx(sr2-ti1,si2+tr1,wp)
end subroutine fft27t