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Diffstat (limited to 'src/fftw3/rdft/dft-r2hc.c')
| -rw-r--r-- | src/fftw3/rdft/dft-r2hc.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/fftw3/rdft/dft-r2hc.c b/src/fftw3/rdft/dft-r2hc.c new file mode 100644 index 0000000..10abf68 --- /dev/null +++ b/src/fftw3/rdft/dft-r2hc.c @@ -0,0 +1,187 @@ +/* + * 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: dft-r2hc.c,v 1.1 2008/10/17 06:11:29 scuri Exp $ */ + +/* Compute the complex DFT by combining R2HC RDFTs on the real + and imaginary parts. This could be useful for people just wanting + to link to the real codelets and not the complex ones. It could + also even be faster than the complex algorithms for split (as opposed + to interleaved) real/imag complex data. */ + +#include "rdft.h" +#include "dft.h" + +typedef struct { + solver super; +} S; + +typedef struct { + plan_dft super; + plan *cld; + int os; + int n; +} P; + +static void apply(const plan *ego_, R *ri, R *ii, R *ro, R *io) +{ + const P *ego = (const P *) ego_; + int os; + int i, n; + + UNUSED(ii); + + { /* transform vector of real & imag parts: */ + plan_rdft *cld = (plan_rdft *) ego->cld; + cld->apply((plan *) cld, ri, ro); + } + + os = ego->os; + n = ego->n; + for (i = 1; i < (n + 1)/2; ++i) { + R rop, iop, iom, rom; + rop = ro[os * i]; + iop = io[os * i]; + rom = ro[os * (n - i)]; + iom = io[os * (n - i)]; + ro[os * i] = rop - iom; + io[os * i] = iop + rom; + ro[os * (n - i)] = rop + iom; + io[os * (n - i)] = iop - rom; + } +} + +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, "(dft-r2hc-%d%(%p%))", ego->n, ego->cld); +} + +#define ALLOW_RANK0 0 /* disable for now, subject to testing */ + +static int applicable0(const problem *p_) +{ + if (DFTP(p_)) { + const problem_dft *p = (const problem_dft *) p_; + return ((p->sz->rnk == 1 && p->vecsz->rnk == 0) +#if ALLOW_RANK0 + || p->sz->rnk == 0 +#endif + ); + } + + return 0; +} + +static int split(R *r, R *i, int n, int s) +{ + return ((r > i ? r - i : i - r) >= ((int)n) * (s > 0 ? s : -s)); +} + +static int applicable(const problem *p_, const planner *plnr) +{ + if (!applicable0(p_)) return 0; + + { + const problem_dft *p = (const problem_dft *) p_; + if (NO_UGLYP(plnr) && DFT_R2HC_ICKYP(plnr)) return 0; + + if (p->sz->rnk == 1 && + split(p->ri, p->ii, p->sz->dims[0].n, p->sz->dims[0].is) && + split(p->ro, p->io, p->sz->dims[0].n, p->sz->dims[0].os)) + return 1; + + return !(NO_UGLYP(plnr)); + } +} + +static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr) +{ + P *pln; + const problem_dft *p; + plan *cld; + + static const plan_adt padt = { + X(dft_solve), awake, print, destroy + }; + + UNUSED(ego_); + if (!applicable(p_, plnr)) + return (plan *)0; + + p = (const problem_dft *) p_; + + { + tensor *ri_vec = X(mktensor_1d)(2, p->ii - p->ri, p->io - p->ro); + tensor *cld_vec = X(tensor_append)(ri_vec, p->vecsz); + cld = X(mkplan_d)(plnr, + X(mkproblem_rdft_1)(p->sz, cld_vec, + p->ri, p->ro, R2HC)); + X(tensor_destroy2)(ri_vec, cld_vec); + } + if (!cld) return (plan *)0; + + pln = MKPLAN_DFT(P, &padt, apply); + +#if ALLOW_RANK0 + if (p->sz->rnk == 0) { + pln->n = 1; + pln->os = 0; + } + else +#endif + { + 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 += 8 * ((pln->n - 1)/2); + pln->super.super.ops.add += 4 * ((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(dft_r2hc_register)(planner *p) +{ + REGISTER_SOLVER(p, mksolver()); +} |