/*

 * 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

 *

 */

/* direct RDFT solver, using r2r codelets */

#include "rdft/rdft.h"

typedef struct {

     solver super;

     const kr2r_desc *desc;

     kr2r k;

} S;

typedef struct {

     plan_rdft super;

     INT vl, ivs, ovs;

     stride is, os;

     kr2r k;

     const S *slv;

} P;

static void apply(const plan *ego_, R *I, R *O)

{

     const P *ego = (const P *) ego_;

     ASSERT_ALIGNED_DOUBLE;

     ego->k(I, O, ego->is, ego->os, ego->vl, ego->ivs, ego->ovs);

}

static void destroy(plan *ego_)

{

     P *ego = (P *) ego_;

     X(stride_destroy)(ego->is);

     X(stride_destroy)(ego->os);

}

static void print(const plan *ego_, printer *p)

{

     const P *ego = (const P *) ego_;

     const S *s = ego->slv;

     p->print(p, "(rdft-%s-direct-r2r-%D%v \"%s\")", 

        X(rdft_kind_str)(s->desc->kind), s->desc->n,

        ego->vl, s->desc->nam);

}

static int applicable(const solver *ego_, const problem *p_)

{

     const S *ego = (const S *) ego_;

     const problem_rdft *p = (const problem_rdft *) p_;

     INT vl;

     INT ivs, ovs;

     return (

    1

    && p->sz->rnk == 1

    && p->vecsz->rnk <= 1

    && p->sz->dims[0].n == ego->desc->n

    && p->kind[0] == ego->desc->kind

    /* check strides etc */

    && X(tensor_tornk1)(p->vecsz, &vl, &ivs, &ovs)

    && (0

        /* can operate out-of-place */

        || p->I != p->O

        /* computing one transform */

        || vl == 1

        /* can operate in-place as long as strides are the same */

        || X(tensor_inplace_strides2)(p->sz, p->vecsz)

         )

    );

}

static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr)

{

     const S *ego = (const S *) ego_;

     P *pln;

     const problem_rdft *p;

     iodim *d;

     static const plan_adt padt = {

    X(rdft_solve), X(null_awake), print, destroy

     };

     UNUSED(plnr);

     if (!applicable(ego_, p_))

          return (plan *)0;

     p = (const problem_rdft *) p_;

     pln = MKPLAN_RDFT(P, &padt, apply);

     d = p->sz->dims;

     pln->k = ego->k;

     pln->is = X(mkstride)(d->n, d->is);

     pln->os = X(mkstride)(d->n, d->os);

     X(tensor_tornk1)(p->vecsz, &pln->vl, &pln->ivs, &pln->ovs);

     pln->slv = ego;

     X(ops_zero)(&pln->super.super.ops);

     X(ops_madd2)(pln->vl / ego->desc->genus->vl,

      &ego->desc->ops,

      &pln->super.super.ops);

     pln->super.super.could_prune_now_p = 1;

     return &(pln->super.super);

}

/* constructor */

solver *X(mksolver_rdft_r2r_direct)(kr2r k, const kr2r_desc *desc)

{

     static const solver_adt sadt = { PROBLEM_RDFT, mkplan, 0 };

     S *slv = MKSOLVER(S, &sadt);

     slv->k = k;

     slv->desc = desc;

     return &(slv->super);

}