view Lib/fftw-3.2.1/reodft/reodft11e-r2hc.c @ 1:e86e9c111b29

Updates stuff that potentially fixes the memory leak and also makes it work on Windows and Linux (Need to test). Still have to fix fftw include for linux in Jucer.

/*
 * Copyright (c) 2003, 2007-8 Matteo Frigo
 * Copyright (c) 2003, 2007-8 Massachusetts Institute of Technology
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


/* Do an R{E,O}DFT11 problem via an R2HC problem, with some
   pre/post-processing ala FFTPACK.  Use a trick from: 

     S. C. Chan and K. L. Ho, "Direct methods for computing discrete
     sinusoidal transforms," IEE Proceedings F 137 (6), 433--442 (1990).

   to re-express as an REDFT01 (DCT-III) problem.

   NOTE: We no longer use this algorithm, because it turns out to suffer
   a catastrophic loss of accuracy for certain inputs, apparently because
   its post-processing multiplies the output by a cosine.  Near the zero
   of the cosine, the REDFT01 must produce a near-singular output.
*/

#include "reodft.h"

typedef struct {
     solver super;
} S;

typedef struct {
     plan_rdft super;
     plan *cld;
     twid *td, *td2;
     INT is, os;
     INT n;
     INT vl;
     INT ivs, ovs;
     rdft_kind kind;
} P;

static void apply_re11(const plan *ego_, R *I, R *O)
{
     const P *ego = (const P *) ego_;
     INT is = ego->is, os = ego->os;
     INT i, n = ego->n;
     INT iv, vl = ego->vl;
     INT ivs = ego->ivs, ovs = ego->ovs;
     R *W;
     R *buf;
     E cur;

     buf = (R *) MALLOC(sizeof(R) * n, BUFFERS);

     for (iv = 0; iv < vl; ++iv, I += ivs, O += ovs) {
	  /* I wish that this didn't require an extra pass. */
	  /* FIXME: use recursive/cascade summation for better stability? */
	  buf[n - 1] = cur = K(2.0) * I[is * (n - 1)];
	  for (i = n - 1; i > 0; --i) {
	       E curnew;
	       buf[(i - 1)] = curnew = K(2.0) * I[is * (i - 1)] - cur;
	       cur = curnew;
	  }
	  
	  W = ego->td->W;
	  for (i = 1; i < n - i; ++i) {
	       E a, b, apb, amb, wa, wb;
	       a = buf[i];
	       b = buf[n - i];
	       apb = a + b;
	       amb = a - b;
	       wa = W[2*i];
	       wb = W[2*i + 1];
	       buf[i] = wa * amb + wb * apb; 
	       buf[n - i] = wa * apb - wb * amb; 
	  }
	  if (i == n - i) {
	       buf[i] = K(2.0) * buf[i] * W[2*i];
	  }
	  
	  {
	       plan_rdft *cld = (plan_rdft *) ego->cld;
	       cld->apply((plan *) cld, buf, buf);
	  }
	  
	  W = ego->td2->W;
	  O[0] = W[0] * buf[0];
	  for (i = 1; i < n - i; ++i) {
	       E a, b;
	       INT k;
	       a = buf[i];
	       b = buf[n - i];
	       k = i + i;
	       O[os * (k - 1)] = W[k - 1] * (a - b);
	       O[os * k] = W[k] * (a + b);
	  }
	  if (i == n - i) {
	       O[os * (n - 1)] = W[n - 1] * buf[i];
	  }
     }

     X(ifree)(buf);
}

/* like for rodft01, rodft11 is obtained from redft11 by
   reversing the input and flipping the sign of every other output. */
static void apply_ro11(const plan *ego_, R *I, R *O)
{
     const P *ego = (const P *) ego_;
     INT is = ego->is, os = ego->os;
     INT i, n = ego->n;
     INT iv, vl = ego->vl;
     INT ivs = ego->ivs, ovs = ego->ovs;
     R *W;
     R *buf;
     E cur;

     buf = (R *) MALLOC(sizeof(R) * n, BUFFERS);

     for (iv = 0; iv < vl; ++iv, I += ivs, O += ovs) {
	  /* I wish that this didn't require an extra pass. */
	  /* FIXME: use recursive/cascade summation for better stability? */
	  buf[n - 1] = cur = K(2.0) * I[0];
	  for (i = n - 1; i > 0; --i) {
	       E curnew;
	       buf[(i - 1)] = curnew = K(2.0) * I[is * (n - i)] - cur;
	       cur = curnew;
	  }
	  
	  W = ego->td->W;
	  for (i = 1; i < n - i; ++i) {
	       E a, b, apb, amb, wa, wb;
	       a = buf[i];
	       b = buf[n - i];
	       apb = a + b;
	       amb = a - b;
	       wa = W[2*i];
	       wb = W[2*i + 1];
	       buf[i] = wa * amb + wb * apb; 
	       buf[n - i] = wa * apb - wb * amb; 
	  }
	  if (i == n - i) {
	       buf[i] = K(2.0) * buf[i] * W[2*i];
	  }
	  
	  {
	       plan_rdft *cld = (plan_rdft *) ego->cld;
	       cld->apply((plan *) cld, buf, buf);
	  }
	  
	  W = ego->td2->W;
	  O[0] = W[0] * buf[0];
	  for (i = 1; i < n - i; ++i) {
	       E a, b;
	       INT k;
	       a = buf[i];
	       b = buf[n - i];
	       k = i + i;
	       O[os * (k - 1)] = W[k - 1] * (b - a);
	       O[os * k] = W[k] * (a + b);
	  }
	  if (i == n - i) {
	       O[os * (n - 1)] = -W[n - 1] * buf[i];
	  }
     }

     X(ifree)(buf);
}

static void awake(plan *ego_, enum wakefulness wakefulness)
{
     P *ego = (P *) ego_;
     static const tw_instr reodft010e_tw[] = {
          { TW_COS, 0, 1 },
          { TW_SIN, 0, 1 },
          { TW_NEXT, 1, 0 }
     };
     static const tw_instr reodft11e_tw[] = {
          { TW_COS, 1, 1 },
          { TW_NEXT, 2, 0 }
     };

     X(plan_awake)(ego->cld, wakefulness);

     X(twiddle_awake)(wakefulness,
		      &ego->td, reodft010e_tw, 4*ego->n, 1, ego->n/2+1);
     X(twiddle_awake)(wakefulness,
		      &ego->td2, reodft11e_tw, 8*ego->n, 1, ego->n * 2);
}

static void destroy(plan *ego_)
{
     P *ego = (P *) ego_;
     X(plan_destroy_internal)(ego->cld);
}

static void print(const plan *ego_, printer *p)
{
     const P *ego = (const P *) ego_;
     p->print(p, "(%se-r2hc-%D%v%(%p%))",
	      X(rdft_kind_str)(ego->kind), ego->n, ego->vl, ego->cld);
}

static int applicable0(const solver *ego_, const problem *p_)
{
     const problem_rdft *p = (const problem_rdft *) p_;

     UNUSED(ego_);

     return (1
	     && p->sz->rnk == 1
	     && p->vecsz->rnk <= 1
	     && (p->kind[0] == REDFT11 || p->kind[0] == RODFT11)
	  );
}

static int applicable(const solver *ego, const problem *p, const planner *plnr)
{
     return (!NO_SLOWP(plnr) && applicable0(ego, p));
}

static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr)
{
     P *pln;
     const problem_rdft *p;
     plan *cld;
     R *buf;
     INT n;
     opcnt ops;

     static const plan_adt padt = {
	  X(rdft_solve), awake, print, destroy
     };

     if (!applicable(ego_, p_, plnr))
          return (plan *)0;

     p = (const problem_rdft *) p_;

     n = p->sz->dims[0].n;
     buf = (R *) MALLOC(sizeof(R) * n, BUFFERS);

     cld = X(mkplan_d)(plnr, X(mkproblem_rdft_1_d)(X(mktensor_1d)(n, 1, 1),
                                                   X(mktensor_0d)(),
                                                   buf, buf, R2HC));
     X(ifree)(buf);
     if (!cld)
          return (plan *)0;

     pln = MKPLAN_RDFT(P, &padt, p->kind[0]==REDFT11 ? apply_re11:apply_ro11);
     pln->n = n;
     pln->is = p->sz->dims[0].is;
     pln->os = p->sz->dims[0].os;
     pln->cld = cld;
     pln->td = pln->td2 = 0;
     pln->kind = p->kind[0];
     
     X(tensor_tornk1)(p->vecsz, &pln->vl, &pln->ivs, &pln->ovs);
     
     X(ops_zero)(&ops);
     ops.other = 5 + (n-1) * 2 + (n-1)/2 * 12 + (1 - n % 2) * 6;
     ops.add = (n - 1) * 1 + (n-1)/2 * 6;
     ops.mul = 2 + (n-1) * 1 + (n-1)/2 * 6 + (1 - n % 2) * 3;

     X(ops_zero)(&pln->super.super.ops);
     X(ops_madd2)(pln->vl, &ops, &pln->super.super.ops);
     X(ops_madd2)(pln->vl, &cld->ops, &pln->super.super.ops);

     return &(pln->super.super);
}

/* constructor */
static solver *mksolver(void)
{
     static const solver_adt sadt = { PROBLEM_RDFT, mkplan, 0 };
     S *slv = MKSOLVER(S, &sadt);
     return &(slv->super);
}

void X(reodft11e_r2hc_register)(planner *p)
{
     REGISTER_SOLVER(p, mksolver());
}