Mercurial > octave-nkf
view libcruft/fftpack/zfftb1.f @ 7789:82be108cc558
First attempt at single precision tyeps
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corrections to qrupdate single precision routines
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prefer demotion to single over promotion to double
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Add single precision support to log2 function
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Trivial PROJECT file update
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Cache optimized hermitian/transpose methods
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Add tests for tranpose/hermitian and ChangeLog entry for new transpose code
author | David Bateman <dbateman@free.fr> |
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date | Sun, 27 Apr 2008 22:34:17 +0200 |
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subroutine zfftb1 (n,c,ch,wa,ifac) implicit double precision (a-h,o-z) dimension ch(*) ,c(*) ,wa(*) ,ifac(*) nf = ifac(2) na = 0 l1 = 1 iw = 1 do 116 k1=1,nf ip = ifac(k1+2) l2 = ip*l1 ido = n/l2 idot = ido+ido idl1 = idot*l1 if (ip .ne. 4) go to 103 ix2 = iw+idot ix3 = ix2+idot if (na .ne. 0) go to 101 call zpassb4 (idot,l1,c,ch,wa(iw),wa(ix2),wa(ix3)) go to 102 101 call zpassb4 (idot,l1,ch,c,wa(iw),wa(ix2),wa(ix3)) 102 na = 1-na go to 115 103 if (ip .ne. 2) go to 106 if (na .ne. 0) go to 104 call zpassb2 (idot,l1,c,ch,wa(iw)) go to 105 104 call zpassb2 (idot,l1,ch,c,wa(iw)) 105 na = 1-na go to 115 106 if (ip .ne. 3) go to 109 ix2 = iw+idot if (na .ne. 0) go to 107 call zpassb3 (idot,l1,c,ch,wa(iw),wa(ix2)) go to 108 107 call zpassb3 (idot,l1,ch,c,wa(iw),wa(ix2)) 108 na = 1-na go to 115 109 if (ip .ne. 5) go to 112 ix2 = iw+idot ix3 = ix2+idot ix4 = ix3+idot if (na .ne. 0) go to 110 call zpassb5 (idot,l1,c,ch,wa(iw),wa(ix2),wa(ix3),wa(ix4)) go to 111 110 call zpassb5 (idot,l1,ch,c,wa(iw),wa(ix2),wa(ix3),wa(ix4)) 111 na = 1-na go to 115 112 if (na .ne. 0) go to 113 call zpassb (nac,idot,ip,l1,idl1,c,c,c,ch,ch,wa(iw)) go to 114 113 call zpassb (nac,idot,ip,l1,idl1,ch,ch,ch,c,c,wa(iw)) 114 if (nac .ne. 0) na = 1-na 115 l1 = l2 iw = iw+(ip-1)*idot 116 continue if (na .eq. 0) return n2 = n+n do 117 i=1,n2 c(i) = ch(i) 117 continue return end