furnace/extern/fftw/dft/dftw-generic.c

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/*
* Copyright (c) 2003, 2007-14 Matteo Frigo
* Copyright (c) 2003, 2007-14 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
/* express a twiddle problem in terms of dft + multiplication by
twiddle factors */
#include "dft/ct.h"
typedef ct_solver S;
typedef struct {
plan_dftw super;
INT r, rs, m, mb, me, ms, v, vs;
plan *cld;
twid *td;
const S *slv;
int dec;
} P;
static void mktwiddle(P *ego, enum wakefulness wakefulness)
{
static const tw_instr tw[] = { { TW_FULL, 0, 0 }, { TW_NEXT, 1, 0 } };
/* note that R and M are swapped, to allow for sequential
access both to data and twiddles */
X(twiddle_awake)(wakefulness, &ego->td, tw,
ego->r * ego->m, ego->m, ego->r);
}
static void bytwiddle(const P *ego, R *rio, R *iio)
{
INT iv, ir, im;
INT r = ego->r, rs = ego->rs;
INT m = ego->m, mb = ego->mb, me = ego->me, ms = ego->ms;
INT v = ego->v, vs = ego->vs;
const R *W = ego->td->W;
mb += (mb == 0); /* skip m=0 iteration */
for (iv = 0; iv < v; ++iv) {
for (ir = 1; ir < r; ++ir) {
for (im = mb; im < me; ++im) {
R *pr = rio + ms * im + rs * ir;
R *pi = iio + ms * im + rs * ir;
E xr = *pr;
E xi = *pi;
E wr = W[2 * im + (2 * (m-1)) * ir - 2];
E wi = W[2 * im + (2 * (m-1)) * ir - 1];
*pr = xr * wr + xi * wi;
*pi = xi * wr - xr * wi;
}
}
rio += vs;
iio += vs;
}
}
static int applicable(INT irs, INT ors, INT ivs, INT ovs,
const planner *plnr)
{
return (1
&& irs == ors
&& ivs == ovs
&& !NO_SLOWP(plnr)
);
}
static void apply_dit(const plan *ego_, R *rio, R *iio)
{
const P *ego = (const P *) ego_;
plan_dft *cld;
INT dm = ego->ms * ego->mb;
bytwiddle(ego, rio, iio);
cld = (plan_dft *) ego->cld;
cld->apply(ego->cld, rio + dm, iio + dm, rio + dm, iio + dm);
}
static void apply_dif(const plan *ego_, R *rio, R *iio)
{
const P *ego = (const P *) ego_;
plan_dft *cld;
INT dm = ego->ms * ego->mb;
cld = (plan_dft *) ego->cld;
cld->apply(ego->cld, rio + dm, iio + dm, rio + dm, iio + dm);
bytwiddle(ego, rio, iio);
}
static void awake(plan *ego_, enum wakefulness wakefulness)
{
P *ego = (P *) ego_;
X(plan_awake)(ego->cld, wakefulness);
mktwiddle(ego, wakefulness);
}
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, "(dftw-generic-%s-%D-%D%v%(%p%))",
ego->dec == DECDIT ? "dit" : "dif",
ego->r, ego->m, ego->v, ego->cld);
}
static plan *mkcldw(const ct_solver *ego_,
INT r, INT irs, INT ors,
INT m, INT ms,
INT v, INT ivs, INT ovs,
INT mstart, INT mcount,
R *rio, R *iio,
planner *plnr)
{
const S *ego = (const S *)ego_;
P *pln;
plan *cld = 0;
INT dm = ms * mstart;
static const plan_adt padt = {
0, awake, print, destroy
};
A(mstart >= 0 && mstart + mcount <= m);
if (!applicable(irs, ors, ivs, ovs, plnr))
return (plan *)0;
cld = X(mkplan_d)(plnr,
X(mkproblem_dft_d)(
X(mktensor_1d)(r, irs, irs),
X(mktensor_2d)(mcount, ms, ms, v, ivs, ivs),
rio + dm, iio + dm, rio + dm, iio + dm)
);
if (!cld) goto nada;
pln = MKPLAN_DFTW(P, &padt, ego->dec == DECDIT ? apply_dit : apply_dif);
pln->slv = ego;
pln->cld = cld;
pln->r = r;
pln->rs = irs;
pln->m = m;
pln->ms = ms;
pln->v = v;
pln->vs = ivs;
pln->mb = mstart;
pln->me = mstart + mcount;
pln->dec = ego->dec;
pln->td = 0;
{
double n0 = (r - 1) * (mcount - 1) * v;
pln->super.super.ops = cld->ops;
pln->super.super.ops.mul += 8 * n0;
pln->super.super.ops.add += 4 * n0;
pln->super.super.ops.other += 8 * n0;
}
return &(pln->super.super);
nada:
X(plan_destroy_internal)(cld);
return (plan *) 0;
}
static void regsolver(planner *plnr, INT r, int dec)
{
S *slv = (S *)X(mksolver_ct)(sizeof(S), r, dec, mkcldw, 0);
REGISTER_SOLVER(plnr, &(slv->super));
if (X(mksolver_ct_hook)) {
slv = (S *)X(mksolver_ct_hook)(sizeof(S), r, dec, mkcldw, 0);
REGISTER_SOLVER(plnr, &(slv->super));
}
}
void X(ct_generic_register)(planner *p)
{
regsolver(p, 0, DECDIT);
regsolver(p, 0, DECDIF);
}