diff options
Diffstat (limited to 'src/fftw3/reodft/redft00e-r2hc-pad.c')
| -rw-r--r-- | src/fftw3/reodft/redft00e-r2hc-pad.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/src/fftw3/reodft/redft00e-r2hc-pad.c b/src/fftw3/reodft/redft00e-r2hc-pad.c new file mode 100644 index 0000000..ec3fa35 --- /dev/null +++ b/src/fftw3/reodft/redft00e-r2hc-pad.c @@ -0,0 +1,201 @@ +/* + * 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: redft00e-r2hc-pad.c,v 1.1 2008/10/17 06:13:18 scuri Exp $ */ + +/* Do a REDFT00 problem via an R2HC problem, padded symmetrically to + twice the size. This is asymptotically a factor of ~2 worse than + redft00e-r2hc.c (the algorithm used in e.g. FFTPACK and Numerical + Recipes), but we abandoned the latter after we discovered that it + has intrinsic accuracy problems. */ + +#include "reodft.h" + +typedef struct { + solver super; +} S; + +typedef struct { + plan_rdft super; + plan *cld, *cldcpy; + int is; + int n; + int vl; + int ivs, ovs; +} P; + +static void apply(const plan *ego_, R *I, R *O) +{ + const P *ego = (const P *) ego_; + int is = ego->is; + int i, n = ego->n; + int iv, vl = ego->vl; + int ivs = ego->ivs, ovs = ego->ovs; + R *buf; + + buf = (R *) MALLOC(sizeof(R) * (2*n), BUFFERS); + + for (iv = 0; iv < vl; ++iv, I += ivs, O += ovs) { + buf[0] = I[0]; + for (i = 1; i < n; ++i) { + R a = I[i * is]; + buf[i] = a; + buf[2*n - i] = a; + } + buf[i] = I[i * is]; /* i == n, Nyquist */ + + /* r2hc transform of size 2*n */ + { + plan_rdft *cld = (plan_rdft *) ego->cld; + cld->apply((plan *) cld, buf, buf); + } + + /* copy n+1 real numbers (real parts of hc array) from buf to O */ + { + plan_rdft *cldcpy = (plan_rdft *) ego->cldcpy; + cldcpy->apply((plan *) cldcpy, buf, O); + } + } + + X(ifree)(buf); +} + +static void awake(plan *ego_, int flg) +{ + P *ego = (P *) ego_; + AWAKE(ego->cld, flg); + AWAKE(ego->cldcpy, flg); +} + +static void destroy(plan *ego_) +{ + P *ego = (P *) ego_; + X(plan_destroy_internal)(ego->cldcpy); + X(plan_destroy_internal)(ego->cld); +} + +static void print(const plan *ego_, printer *p) +{ + const P *ego = (const P *) ego_; + p->print(p, "(redft00e-r2hc-pad-%d%v%(%p%)%(%p%))", + ego->n + 1, ego->vl, ego->cld, ego->cldcpy); +} + +static int applicable0(const solver *ego_, const problem *p_) +{ + UNUSED(ego_); + if (RDFTP(p_)) { + const problem_rdft *p = (const problem_rdft *) p_; + return (1 + && p->sz->rnk == 1 + && p->vecsz->rnk <= 1 + && p->kind[0] == REDFT00 + && p->sz->dims[0].n > 1 /* n == 1 is not well-defined */ + ); + } + + return 0; +} + +static int applicable(const solver *ego, const problem *p, const planner *plnr) +{ + return (!NO_UGLYP(plnr) && applicable0(ego, p)); +} + +static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr) +{ + P *pln; + const problem_rdft *p; + plan *cld = (plan *) 0, *cldcpy; + R *buf = (R *) 0; + int n; + int vl, ivs, ovs; + opcnt ops; + + static const plan_adt padt = { + X(rdft_solve), awake, print, destroy + }; + + if (!applicable(ego_, p_, plnr)) + goto nada; + + p = (const problem_rdft *) p_; + + n = p->sz->dims[0].n - 1; + A(n > 0); + buf = (R *) MALLOC(sizeof(R) * (2*n), BUFFERS); + + cld = X(mkplan_d)(plnr,X(mkproblem_rdft_1_d)(X(mktensor_1d)(2*n,1,1), + X(mktensor_0d)(), + buf, buf, R2HC)); + if (!cld) + goto nada; + + X(tensor_tornk1)(p->vecsz, &vl, &ivs, &ovs); + cldcpy = + X(mkplan_d)(plnr, + X(mkproblem_rdft_1_d)(X(mktensor_0d)(), + X(mktensor_1d)(n+1,1, + p->sz->dims[0].os), + buf, TAINT(p->O, ovs), R2HC)); + if (!cldcpy) + goto nada; + + X(ifree)(buf); + + pln = MKPLAN_RDFT(P, &padt, apply); + + pln->n = n; + pln->is = p->sz->dims[0].is; + pln->cld = cld; + pln->cldcpy = cldcpy; + pln->vl = vl; + pln->ivs = ivs; + pln->ovs = ovs; + + X(ops_zero)(&ops); + ops.other = n + 2*n; /* loads + stores (input -> buf) */ + + 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); + X(ops_madd2)(pln->vl, &cldcpy->ops, &pln->super.super.ops); + + return &(pln->super.super); + + nada: + X(ifree0)(buf); + if (cld) + X(plan_destroy_internal)(cld); + return (plan *)0; +} + +/* constructor */ +static solver *mksolver(void) +{ + static const solver_adt sadt = { mkplan }; + S *slv = MKSOLVER(S, &sadt); + return &(slv->super); +} + +void X(redft00e_r2hc_pad_register)(planner *p) +{ + REGISTER_SOLVER(p, mksolver()); +} |