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authorscuri <scuri>2009-08-20 12:35:06 +0000
committerscuri <scuri>2009-08-20 12:35:06 +0000
commit5d735255ddd3cb2f547abd3d03969af3fb7eb04e (patch)
tree8fb66510bc625bb1b08ccb41f1b83fb0f7cb8f19 /src/fftw3/dft/rader.c
parent35733b87eed86e5228f12fa10c98a3d9d22a6073 (diff)
*** empty log message ***
Diffstat (limited to 'src/fftw3/dft/rader.c')
-rw-r--r--src/fftw3/dft/rader.c491
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diff --git a/src/fftw3/dft/rader.c b/src/fftw3/dft/rader.c
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index f31f370..0000000
--- a/src/fftw3/dft/rader.c
+++ /dev/null
@@ -1,491 +0,0 @@
-/*
- * Copyright (c) 2003 Matteo Frigo
- * Copyright (c) 2003 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
- *
- */
-
-#include "dft.h"
-
-/*
- * Compute transforms of prime sizes using Rader's trick: turn them
- * into convolutions of size n - 1, which you then perform via a pair
- * of FFTs. This file contains both nontwiddle (direct) and
- * twiddle (DIT Cooley-Tukey) solvers.
- */
-
-typedef struct {
- solver super;
-} S;
-
-typedef struct {
- plan_dft super;
-
- plan *cld1, *cld2;
- R *omega;
- int n, g, ginv;
- int is, os;
- plan *cld_omega;
-} P;
-
-typedef struct {
- P super;
- plan *cld;
- R *W;
- int os;
- int m;
-} P_dit;
-
-
-static rader_tl *twiddles = 0;
-
-/***************************************************************************/
-
-/* Below, we extensively use the identity that fft(x*)* = ifft(x) in
- order to share data between forward and backward transforms and to
- obviate the necessity of having separate forward and backward
- plans. (Although we often compute separate plans these days anyway
- due to the differing strides, etcetera.)
-
- Of course, since the new FFTW gives us separate pointers to
- the real and imaginary parts, we could have instead used the
- fft(r,i) = ifft(i,r) form of this identity, but it was easier to
- reuse the code from our old version. */
-
-static void apply_aux(int r, int ginv, plan *cld1,plan *cld2, const R *omega,
- R *buf, R r0, R i0, R *ro, R *io, int os)
-{
- int gpower, k;
-
- /* compute DFT of buf, storing in output (except DC): */
- {
- plan_dft *cld = (plan_dft *) cld1;
- cld->apply(cld1, buf, buf+1, ro+os, io+os);
- }
-
- /* set output DC component: */
- ro[0] = r0 + ro[os];
- io[0] = i0 + io[os];
-
- /* now, multiply by omega: */
- for (k = 0; k < r - 1; ++k) {
- E rB, iB, rW, iW;
- rW = omega[2*k];
- iW = omega[2*k+1];
- rB = ro[(k+1)*os];
- iB = io[(k+1)*os];
- ro[(k+1)*os] = rW * rB - iW * iB;
- io[(k+1)*os] = -(rW * iB + iW * rB);
- }
-
- /* this will add input[0] to all of the outputs after the ifft */
- ro[os] += r0;
- io[os] -= i0;
-
- /* inverse FFT: */
- {
- plan_dft *cld = (plan_dft *) cld2;
- cld->apply(cld2, ro+os, io+os, buf, buf+1);
- }
-
- /* finally, do inverse permutation to unshuffle the output: */
- gpower = 1;
- for (k = 0; k < r - 1; ++k, gpower = MULMOD(gpower, ginv, r)) {
- ro[gpower * os] = buf[2*k];
- io[gpower * os] = -buf[2*k+1];
- }
- A(gpower == 1);
-}
-
-static void apply(const plan *ego_, R *ri, R *ii, R *ro, R *io)
-{
- const P *ego = (const P *) ego_;
- int is;
- int k, gpower, g, r;
- R *buf;
-
- r = ego->n; is = ego->is; g = ego->g;
- buf = (R *) MALLOC(sizeof(R) * (r - 1) * 2, BUFFERS);
-
- /* First, permute the input, storing in buf: */
- for (gpower = 1, k = 0; k < r - 1; ++k, gpower = MULMOD(gpower, g, r)) {
- R rA, iA;
- rA = ri[gpower * is];
- iA = ii[gpower * is];
- buf[2*k] = rA; buf[2*k + 1] = iA;
- }
- /* gpower == g^(r-1) mod r == 1 */;
-
- apply_aux(r, ego->ginv, ego->cld1, ego->cld2, ego->omega,
- buf, ri[0], ii[0], ro, io, ego->os);
-
- X(ifree)(buf);
-}
-
-static void apply_dit(const plan *ego_, R *ri, R *ii, R *ro, R *io)
-{
- const P_dit *ego_dit = (const P_dit *) ego_;
- const P *ego;
- plan *cld1, *cld2;
- int os, osm;
- int j, k, gpower, g, ginv, r, m;
- R *buf;
- const R *omega, *W;
-
- {
- plan *cld0 = ego_dit->cld;
- plan_dft *cld = (plan_dft *) cld0;
- cld->apply(cld0, ri, ii, ro, io);
- }
-
- ego = (const P *) ego_;
- cld1 = ego->cld1;
- cld2 = ego->cld2;
- r = ego->n;
- m = ego_dit->m;
- g = ego->g;
- ginv = ego->ginv;
- omega = ego->omega;
- W = ego_dit->W;
- os = ego_dit->os;
- osm = ego->os;
- gpower = 1;
-
- buf = (R *) MALLOC(sizeof(R) * (r - 1) * 2, BUFFERS);
-
- for (j = 0; j < m; ++j, ro += os, io += os, W += 2*(r - 1)) {
- /* First, permute the input and multiply by W, storing in buf: */
- A(gpower == 1);
- for (k = 0; k < r - 1; ++k, gpower = MULMOD(gpower, g, r)) {
- E rA, iA, rW, iW;
- rA = ro[gpower * osm];
- iA = io[gpower * osm];
- rW = W[2*k];
- iW = W[2*k+1];
- buf[2*k] = rW * rA - iW * iA;
- buf[2*k + 1] = rW * iA + iW * rA;
- }
- /* gpower == g^(r-1) mod r == 1 */;
-
- apply_aux(r, ginv, cld1, cld2, omega,
- buf, ro[0], io[0], ro, io, osm);
- }
-
- X(ifree)(buf);
-}
-
-static R *mktwiddle(int m, int r, int g)
-{
- int i, j, gpower;
- int n = r * m;
- R *W;
-
- if ((W = X(rader_tl_find)(m, r, g, twiddles)))
- return W;
-
- W = (R *)MALLOC(sizeof(R) * (r - 1) * m * 2, TWIDDLES);
- for (i = 0; i < m; ++i) {
- for (gpower = 1, j = 0; j < r - 1;
- ++j, gpower = MULMOD(gpower, g, r)) {
- int k = i * (r - 1) + j;
- W[2*k] = X(cos2pi)(i * gpower, n);
- W[2*k+1] = FFT_SIGN * X(sin2pi)(i * gpower, n);
- }
- A(gpower == 1);
- }
-
- X(rader_tl_insert)(m, r, g, W, &twiddles);
- return W;
-}
-
-static void free_twiddle(R *twiddle)
-{
- X(rader_tl_delete)(twiddle, &twiddles);
-}
-
-/***************************************************************************/
-
-static void awake(plan *ego_, int flg)
-{
- P *ego = (P *) ego_;
-
- AWAKE(ego->cld1, flg);
- AWAKE(ego->cld2, flg);
-
- if (flg) {
- if (!ego->omega)
- ego->omega =
- X(dft_rader_mkomega)(ego->cld_omega, ego->n, ego->ginv);
- } else {
- X(dft_rader_free_omega)(&ego->omega);
- }
-}
-
-static void awake_dit(plan *ego_, int flg)
-{
- P_dit *ego = (P_dit *) ego_;
-
- AWAKE(ego->cld, flg);
- if (flg)
- ego->W = mktwiddle(ego->m, ego->super.n, ego->super.g);
- else {
- free_twiddle(ego->W);
- ego->W = 0;
- }
-
- awake(ego_, flg);
-}
-
-static void destroy(plan *ego_)
-{
- P *ego = (P *) ego_;
- X(plan_destroy_internal)(ego->cld_omega);
- X(plan_destroy_internal)(ego->cld2);
- X(plan_destroy_internal)(ego->cld1);
-}
-
-static void destroy_dit(plan *ego_)
-{
- P_dit *ego = (P_dit *) ego_;
- X(plan_destroy_internal)(ego->cld);
- destroy(ego_);
-}
-
-static void print_aux(const char *name, const P *ego, printer *p)
-{
- p->print(p, "(%s-%d%ois=%oos=%(%p%)",
- name, ego->n, ego->is, ego->os, ego->cld1);
- if (ego->cld2 != ego->cld1)
- p->print(p, "%(%p%)", ego->cld2);
- if (ego->cld_omega != ego->cld1 && ego->cld_omega != ego->cld2)
- p->print(p, "%(%p%)", ego->cld_omega);
-}
-
-static void print(const plan *ego_, printer *p)
-{
- print_aux("dft-rader", (const P *) ego_, p);
- p->putchr(p, ')');
-}
-
-static void print_dit(const plan *ego_, printer *p)
-{
- const P_dit *ego_dit = (const P_dit *) ego_;
-
- print_aux("dft-rader-dit", (const P *) ego_, p);
- p->print(p, "%(%p%))", ego_dit->cld);
-}
-
-static int applicable0(const solver *ego_, const problem *p_)
-{
- UNUSED(ego_);
- if (DFTP(p_)) {
- const problem_dft *p = (const problem_dft *) p_;
- return (1
- && p->sz->rnk == 1
- && p->vecsz->rnk == 0
- && X(is_prime)(p->sz->dims[0].n)
- );
- }
-
- return 0;
-}
-
-static int applicable0_dit(const solver *ego_, const problem *p_)
-{
- UNUSED(ego_);
- if (DFTP(p_)) {
- const problem_dft *p = (const problem_dft *) p_;
- return (1
- && p->sz->rnk == 1
- && p->vecsz->rnk == 0
- && p->sz->dims[0].n > 1
- );
- }
-
- return 0;
-}
-
-static int applicable(const solver *ego_, const problem *p_,
- const planner *plnr)
-{
- return (!NO_UGLYP(plnr) && applicable0(ego_, p_));
-}
-
-static int applicable_dit(const solver *ego_, const problem *p_,
- const planner *plnr)
-{
- return (!NO_UGLYP(plnr) && applicable0_dit(ego_, p_));
-}
-
-static int mkP(P *pln, int n, int is, int os, R *ro, R *io,
- planner *plnr)
-{
- plan *cld1 = (plan *) 0;
- plan *cld2 = (plan *) 0;
- plan *cld_omega = (plan *) 0;
- R *buf = (R *) 0;
-
- /* initial allocation for the purpose of planning */
- buf = (R *) MALLOC(sizeof(R) * (n - 1) * 2, BUFFERS);
-
- cld1 = X(mkplan_d)(plnr,
- X(mkproblem_dft_d)(X(mktensor_1d)(n - 1, 2, os),
- X(mktensor_1d)(1, 0, 0),
- buf, buf + 1, ro + os, io + os));
- if (!cld1) goto nada;
-
- cld2 = X(mkplan_d)(plnr,
- X(mkproblem_dft_d)(X(mktensor_1d)(n - 1, os, 2),
- X(mktensor_1d)(1, 0, 0),
- ro + os, io + os, buf, buf + 1));
-
- if (!cld2) goto nada;
-
- /* plan for omega array */
- plnr->planner_flags |= ESTIMATE;
- cld_omega = X(mkplan_d)(plnr,
- X(mkproblem_dft_d)(X(mktensor_1d)(n - 1, 2, 2),
- X(mktensor_1d)(1, 0, 0),
- buf, buf + 1, buf, buf + 1));
- if (!cld_omega) goto nada;
-
- /* deallocate buffers; let awake() or apply() allocate them for real */
- X(ifree)(buf);
- buf = 0;
-
- pln->cld1 = cld1;
- pln->cld2 = cld2;
- pln->cld_omega = cld_omega;
- pln->omega = 0;
- pln->n = n;
- pln->is = is;
- pln->os = os;
- pln->g = X(find_generator)(n);
- pln->ginv = X(power_mod)(pln->g, n - 2, n);
- A(MULMOD(pln->g, pln->ginv, n) == 1);
-
- X(ops_add)(&cld1->ops, &cld2->ops, &pln->super.super.ops);
- pln->super.super.ops.other += (n - 1) * (4 * 2 + 6) + 6;
- pln->super.super.ops.add += (n - 1) * 2 + 4;
- pln->super.super.ops.mul += (n - 1) * 4;
-
- return 1;
-
- nada:
- X(ifree0)(buf);
- X(plan_destroy_internal)(cld_omega);
- X(plan_destroy_internal)(cld2);
- X(plan_destroy_internal)(cld1);
- return 0;
-}
-
-static plan *mkplan(const solver *ego, const problem *p_, planner *plnr)
-{
- const problem_dft *p = (const problem_dft *) p_;
- P *pln;
- int n;
- int is, os;
-
- static const plan_adt padt = {
- X(dft_solve), awake, print, destroy
- };
-
- if (!applicable(ego, p_, plnr))
- return (plan *) 0;
-
- n = p->sz->dims[0].n;
- is = p->sz->dims[0].is;
- os = p->sz->dims[0].os;
-
- pln = MKPLAN_DFT(P, &padt, apply);
- if (!mkP(pln, n, is, os, p->ro, p->io, plnr)) {
- X(ifree)(pln);
- return (plan *) 0;
- }
- return &(pln->super.super);
-}
-
-static plan *mkplan_dit(const solver *ego, const problem *p_, planner *plnr)
-{
- const problem_dft *p = (const problem_dft *) p_;
- P_dit *pln = 0;
- int n, r, m;
- int is, os;
- plan *cld = (plan *) 0;
-
- static const plan_adt padt = {
- X(dft_solve), awake_dit, print_dit, destroy_dit
- };
-
- if (!applicable_dit(ego, p_, plnr))
- goto nada;
-
- n = p->sz->dims[0].n;
- is = p->sz->dims[0].is;
- os = p->sz->dims[0].os;
-
- r = X(first_divisor)(n);
- m = n / r;
-
- cld = X(mkplan_d)(plnr,
- X(mkproblem_dft_d)(X(mktensor_1d)(m, r * is, os),
- X(mktensor_1d)(r, is, m * os),
- p->ri, p->ii, p->ro, p->io));
- if (!cld) goto nada;
-
- pln = MKPLAN_DFT(P_dit, &padt, apply_dit);
- if (!mkP(&pln->super, r, os*m, os*m, p->ro, p->io, plnr))
- goto nada;
-
- pln->os = os;
- pln->m = m;
- pln->cld = cld;
- pln->W = 0;
-
- pln->super.super.super.ops.add += 2 * (r-1);
- pln->super.super.super.ops.mul += 4 * (r-1);
- X(ops_madd)(m, &pln->super.super.super.ops, &cld->ops,
- &pln->super.super.super.ops);
-
- return &(pln->super.super.super);
-
- nada:
- X(plan_destroy_internal)(cld);
- X(ifree0)(pln);
- return (plan *) 0;
-}
-
-/* constructors */
-
-static solver *mksolver(void)
-{
- static const solver_adt sadt = { mkplan };
- S *slv = MKSOLVER(S, &sadt);
- return &(slv->super);
-}
-
-static solver *mksolver_dit(void)
-{
- static const solver_adt sadt = { mkplan_dit };
- S *slv = MKSOLVER(S, &sadt);
- return &(slv->super);
-}
-
-void X(dft_rader_register)(planner *p)
-{
- REGISTER_SOLVER(p, mksolver());
- REGISTER_SOLVER(p, mksolver_dit());
-}