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Diffstat (limited to 'src/fftw3/rdft/dht-r2hc.c')
| -rw-r--r-- | src/fftw3/rdft/dht-r2hc.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/fftw3/rdft/dht-r2hc.c b/src/fftw3/rdft/dht-r2hc.c new file mode 100644 index 0000000..e66e614 --- /dev/null +++ b/src/fftw3/rdft/dht-r2hc.c @@ -0,0 +1,148 @@ +/* + * 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 + * + */ + +/* $Id: dht-r2hc.c,v 1.1 2008/10/17 06:11:29 scuri Exp $ */ + +/* Solve a DHT problem (Discrete Hartley Transform) via post-processing + of an R2HC problem. */ + +#include "rdft.h" + +typedef struct { + solver super; +} S; + +typedef struct { + plan_rdft super; + plan *cld; + int os; + int n; +} P; + +static void apply(const plan *ego_, R *I, R *O) +{ + const P *ego = (const P *) ego_; + int os = ego->os; + int i, n = ego->n; + + { + plan_rdft *cld = (plan_rdft *) ego->cld; + cld->apply((plan *) cld, I, O); + } + + for (i = 1; i < n - i; ++i) { + E a, b; + a = O[os * i]; + b = O[os * (n - i)]; +#if FFT_SIGN == -1 + O[os * i] = a - b; + O[os * (n - i)] = a + b; +#else + O[os * i] = a + b; + O[os * (n - i)] = a - b; +#endif + } +} + +static void awake(plan *ego_, int flg) +{ + P *ego = (P *) ego_; + AWAKE(ego->cld, flg); +} + +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, "(dht-r2hc-%d%(%p%))", ego->n, ego->cld); +} + +static int applicable0(const problem *p_, const planner *plnr) +{ + if (RDFTP(p_)) { + const problem_rdft *p = (const problem_rdft *) p_; + return (1 + && !NO_DHT_R2HCP(plnr) + && p->sz->rnk == 1 + && p->vecsz->rnk == 0 + && p->kind[0] == DHT + ); + } + return 0; +} + +static int applicable(const solver *ego, const problem *p, const planner *plnr) +{ + UNUSED(ego); + return (!NO_UGLYP(plnr) && applicable0(p, plnr)); +} + +static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr) +{ + P *pln; + const problem_rdft *p; + plan *cld; + + static const plan_adt padt = { + X(rdft_solve), awake, print, destroy + }; + + if (!applicable(ego_, p_, plnr)) + return (plan *)0; + + p = (const problem_rdft *) p_; + + /* stop infinite loops with rdft-dht.c */ + plnr->problem_flags |= NO_DHT_R2HC; + + cld = X(mkplan_d)(plnr, + X(mkproblem_rdft_1)(p->sz, p->vecsz, p->I, p->O, R2HC)); + if (!cld) return (plan *)0; + + pln = MKPLAN_RDFT(P, &padt, apply); + + pln->n = p->sz->dims[0].n; + pln->os = p->sz->dims[0].os; + pln->cld = cld; + + pln->super.super.ops = cld->ops; + pln->super.super.ops.other += 4 * ((pln->n - 1)/2); + pln->super.super.ops.add += 2 * ((pln->n - 1)/2); + + return &(pln->super.super); +} + +/* constructor */ +static solver *mksolver(void) +{ + static const solver_adt sadt = { mkplan }; + S *slv = MKSOLVER(S, &sadt); + return &(slv->super); +} + +void X(dht_r2hc_register)(planner *p) +{ + REGISTER_SOLVER(p, mksolver()); +} |