src/fftw/fhb_2.c

   1 /*
   2  * Copyright (c) 1997-1999 Massachusetts Institute of Technology
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  *
  18  */
  19
  20 /* This file was automatically generated --- DO NOT EDIT */
  21 /* Generated on Tue May 18 13:55:57 EDT 1999 */
  22
  23 #include <fftw-int.h>
  24 #include <fftw.h>
  25
  26 /* Generated by: ./genfft -magic-alignment-check -magic-twiddle-load-all -magic-variables 4 -magic-loopi -hc2hc-backward 2 */
  27
  28 /*
  29  * This function contains 8 FP additions, 6 FP multiplications,
  30  * (or, 6 additions, 4 multiplications, 2 fused multiply/add),
  31  * 11 stack variables, and 16 memory accesses
  32  */
  33 static const fftw_real K2_000000000 = FFTW_KONST(+2.000000000000000000000000000000000000000000000);
  34
  35 /*
  36  * Generator Id's :
  37  * $Id$
  38  * $Id$
  39  * $Id$
  40  */
  41
  42 void fftw_hc2hc_backward_2(fftw_real *A, const fftw_complex *W, int iostride, int m, int dist)
  43 {
  44      int i;
  45      fftw_real *X;
  46      fftw_real *Y;
  47      X = A;
  48      Y = A + (2 * iostride);
  49      {
  50           fftw_real tmp11;
  51           fftw_real tmp12;
  52           ASSERT_ALIGNED_DOUBLE();
  53           tmp11 = X[0];
  54           tmp12 = X[iostride];
  55           X[iostride] = tmp11 - tmp12;
  56           X[0] = tmp11 + tmp12;
  57      }
  58      X = X + dist;
  59      Y = Y - dist;
  60      for (i = 2; i < m; i = i + 2, X = X + dist, Y = Y - dist, W = W + 1) {
  61           fftw_real tmp3;
  62           fftw_real tmp4;
  63           fftw_real tmp8;
  64           fftw_real tmp5;
  65           fftw_real tmp6;
  66           fftw_real tmp10;
  67           fftw_real tmp7;
  68           fftw_real tmp9;
  69           ASSERT_ALIGNED_DOUBLE();
  70           tmp3 = X[0];
  71           tmp4 = Y[-iostride];
  72           tmp8 = tmp3 - tmp4;
  73           tmp5 = Y[0];
  74           tmp6 = X[iostride];
  75           tmp10 = tmp5 + tmp6;
  76           X[0] = tmp3 + tmp4;
  77           Y[-iostride] = tmp5 - tmp6;
  78           tmp7 = c_re(W[0]);
  79           tmp9 = c_im(W[0]);
  80           X[iostride] = (tmp7 * tmp8) + (tmp9 * tmp10);
  81           Y[0] = (tmp7 * tmp10) - (tmp9 * tmp8);
  82      }
  83      if (i == m) {
  84           fftw_real tmp1;
  85           fftw_real tmp2;
  86           ASSERT_ALIGNED_DOUBLE();
  87           tmp1 = X[0];
  88           X[0] = K2_000000000 * tmp1;
  89           tmp2 = Y[0];
  90           X[iostride] = -(K2_000000000 * tmp2);
  91      }
  92 }
  93
  94 static const int twiddle_order[] =
  95 {1};
  96 fftw_codelet_desc fftw_hc2hc_backward_2_desc =
  97 {
  98      "fftw_hc2hc_backward_2",
  99      (void (*)()) fftw_hc2hc_backward_2,
 100      2,
 101      FFTW_BACKWARD,
 102      FFTW_HC2HC,
 103      58,
 104      1,
 105      twiddle_order,
 106 };