/*

 * 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

 *

 */

#include "ct-hc2c.h"

#include "dft/dft.h"

typedef struct {

     plan_rdft2 super;

     plan *cld;

     plan *cldw;

     INT r;

} P;

static void apply_dit(const plan *ego_, R *r0, R *r1, R *cr, R *ci)

{

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

     plan_rdft *cld;

     plan_hc2c *cldw;

     UNUSED(r1);

     cld = (plan_rdft *) ego->cld;

     cld->apply(ego->cld, r0, cr);

     cldw = (plan_hc2c *) ego->cldw;

     cldw->apply(ego->cldw, cr, ci);

}

static void apply_dif(const plan *ego_, R *r0, R *r1, R *cr, R *ci)

{

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

     plan_rdft *cld;

     plan_hc2c *cldw;

     UNUSED(r1);

     cldw = (plan_hc2c *) ego->cldw;

     cldw->apply(ego->cldw, cr, ci);

     cld = (plan_rdft *) ego->cld;

     cld->apply(ego->cld, cr, r0);

}

static void apply_dit_dft(const plan *ego_, R *r0, R *r1, R *cr, R *ci)

{

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

     plan_dft *cld;

     plan_hc2c *cldw;

     cld = (plan_dft *) ego->cld;

     cld->apply(ego->cld, r0, r1, cr, ci);

     cldw = (plan_hc2c *) ego->cldw;

     cldw->apply(ego->cldw, cr, ci);

}

static void apply_dif_dft(const plan *ego_, R *r0, R *r1, R *cr, R *ci)

{

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

     plan_dft *cld;

     plan_hc2c *cldw;

     cldw = (plan_hc2c *) ego->cldw;

     cldw->apply(ego->cldw, cr, ci);

     cld = (plan_dft *) ego->cld;

     cld->apply(ego->cld, ci, cr, r1, r0);

}

static void awake(plan *ego_, enum wakefulness wakefulness)

{

     P *ego = (P *) ego_;

     X(plan_awake)(ego->cld, wakefulness);

     X(plan_awake)(ego->cldw, wakefulness);

}

static void destroy(plan *ego_)

{

     P *ego = (P *) ego_;

     X(plan_destroy_internal)(ego->cldw);

     X(plan_destroy_internal)(ego->cld);

}

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

{

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

     p->print(p, "(rdft2-ct-%s/%D%(%p%)%(%p%))",

        (ego->super.apply == apply_dit || 

         ego->super.apply == apply_dit_dft)

        ? "dit" : "dif",

        ego->r, ego->cldw, ego->cld);

}

static int applicable0(const hc2c_solver *ego, const problem *p_, planner *plnr)

{

     const problem_rdft2 *p = (const problem_rdft2 *) p_;

     INT r;

     return (1

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

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

       && (/* either the problem is R2HC, which is solved by DIT */

      (p->kind == R2HC)

      ||

      /* or the problem is HC2R, in which case it is solved

         by DIF, which destroys the input */

      (p->kind == HC2R && 

       (p->r0 == p->cr || !NO_DESTROY_INPUTP(plnr))))

       && ((r = X(choose_radix)(ego->r, p->sz->dims[0].n)) > 0)

       && p->sz->dims[0].n > r);

}

static int hc2c_applicable(const hc2c_solver *ego, const problem *p_,

                           planner *plnr)

{

     const problem_rdft2 *p;

     if (!applicable0(ego, p_, plnr))

          return 0;

     p = (const problem_rdft2 *) p_;

     return (0

       || p->vecsz->rnk == 0

       || !NO_VRECURSEP(plnr)

    );

}

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

{

     const hc2c_solver *ego = (const hc2c_solver *) ego_;

     const problem_rdft2 *p;

     P *pln = 0;

     plan *cld = 0, *cldw = 0;

     INT n, r, m, v, ivs, ovs;

     iodim *d;

     static const plan_adt padt = {

    X(rdft2_solve), awake, print, destroy

     };

     if (!hc2c_applicable(ego, p_, plnr))

          return (plan *) 0;

     p = (const problem_rdft2 *) p_;

     d = p->sz->dims;

     n = d[0].n;

     r = X(choose_radix)(ego->r, n);

     A((r % 2) == 0);

     m = n / r;

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

     switch (p->kind) {

   case R2HC:

        cldw = ego->mkcldw(ego, R2HC, 

         r, m * d[0].os, 

         m, d[0].os,

         v, ovs,

         p->cr, p->ci, plnr);

        if (!cldw) goto nada;

        switch (ego->hc2ckind) {

      case HC2C_VIA_RDFT:

           cld = X(mkplan_d)(

          plnr, 

          X(mkproblem_rdft_1_d)(

         X(mktensor_1d)(m, (r/2)*d[0].is, d[0].os),

         X(mktensor_3d)(

              2, p->r1 - p->r0, p->ci - p->cr,

              r / 2, d[0].is, m * d[0].os,

              v, ivs, ovs),

         p->r0, p->cr, R2HC) 

          );

           if (!cld) goto nada;

           pln = MKPLAN_RDFT2(P, &padt, apply_dit);

           break;

      case HC2C_VIA_DFT:

           cld = X(mkplan_d)(

          plnr, 

          X(mkproblem_dft_d)(

         X(mktensor_1d)(m, (r/2)*d[0].is, d[0].os),

         X(mktensor_2d)(

              r / 2, d[0].is, m * d[0].os,

              v, ivs, ovs),

         p->r0, p->r1, p->cr, p->ci) 

          );

           if (!cld) goto nada;

           pln = MKPLAN_RDFT2(P, &padt, apply_dit_dft);

           break;

        }

        break;

   case HC2R:

        cldw = ego->mkcldw(ego, HC2R, 

         r, m * d[0].is, 

         m, d[0].is,

         v, ivs,

         p->cr, p->ci, plnr);

        if (!cldw) goto nada;

        switch (ego->hc2ckind) {

      case HC2C_VIA_RDFT:

           cld = X(mkplan_d)(

          plnr, 

          X(mkproblem_rdft_1_d)(

         X(mktensor_1d)(m, d[0].is, (r/2)*d[0].os),

         X(mktensor_3d)(

              2, p->ci - p->cr, p->r1 - p->r0, 

              r / 2, m * d[0].is, d[0].os,

              v, ivs, ovs),

         p->cr, p->r0, HC2R) 

          );

           if (!cld) goto nada;

           pln = MKPLAN_RDFT2(P, &padt, apply_dif);

           break;

      case HC2C_VIA_DFT:

           cld = X(mkplan_d)(

          plnr, 

          X(mkproblem_dft_d)(

         X(mktensor_1d)(m, d[0].is, (r/2)*d[0].os),

         X(mktensor_2d)(

              r / 2, m * d[0].is, d[0].os,

              v, ivs, ovs),

         p->ci, p->cr, p->r1, p->r0) 

          );

           if (!cld) goto nada;

           pln = MKPLAN_RDFT2(P, &padt, apply_dif_dft);

           break;

        }

        break;

   default: 

        A(0);

     }

     pln->cld = cld;

     pln->cldw = cldw;

     pln->r = r;

     X(ops_add)(&cld->ops, &cldw->ops, &pln->super.super.ops);

     /* inherit could_prune_now_p attribute from cldw */

     pln->super.super.could_prune_now_p = cldw->could_prune_now_p;

     return &(pln->super.super);

 nada:

     X(plan_destroy_internal)(cldw);

     X(plan_destroy_internal)(cld);

     return (plan *) 0;

}

hc2c_solver *X(mksolver_hc2c)(size_t size, INT r, 

            hc2c_kind hc2ckind,

            hc2c_mkinferior mkcldw)

{

     static const solver_adt sadt = { PROBLEM_RDFT2, mkplan, 0 };

     hc2c_solver *slv = (hc2c_solver *)X(mksolver)(size, &sadt);

     slv->r = r;

     slv->hc2ckind = hc2ckind;

     slv->mkcldw = mkcldw;

     return slv;

}

plan *X(mkplan_hc2c)(size_t size, const plan_adt *adt, hc2capply apply)

{

     plan_hc2c *ego;

     ego = (plan_hc2c *) X(mkplan)(size, adt);

     ego->apply = apply;

     return &(ego->super);

}