comparison src/fftw-3.3.3/rdft/dht-r2hc.c @ 10:37bf6b4a2645

Add FFTW3

+/*
+ * Copyright (c) 2003, 2007-11 Matteo Frigo
+ * Copyright (c) 2003, 2007-11 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
+ *
+ */
+
+
+/* Solve a DHT problem (Discrete Hartley Transform) via post-processing
+   of an R2HC problem. */
+
+#include "rdft.h"
+
+typedef struct {
+     solver super;
+} S;
+
+typedef struct {
+     plan_rdft super;
+     plan *cld;
+     INT os;
+     INT n;
+} P;
+
+static void apply(const plan *ego_, R *I, R *O)
+{
+     const P *ego = (const P *) ego_;
+     INT os = ego->os;
+     INT i, n = ego->n;
+
+     {
+	  plan_rdft *cld = (plan_rdft *) ego->cld;
+	  cld->apply((plan *) cld, I, O);
+     }
+
+     for (i = 1; i < n - i; ++i) {
+	  E a, b;
+	  a = O[os * i];
+	  b = O[os * (n - i)];
+#if FFT_SIGN == -1
+	  O[os * i] = a - b;
+	  O[os * (n - i)] = a + b;
+#else
+	  O[os * i] = a + b;
+	  O[os * (n - i)] = a - b;
+#endif
+     }
+}
+
+static void awake(plan *ego_, enum wakefulness wakefulness)
+{
+     P *ego = (P *) ego_;
+     X(plan_awake)(ego->cld, 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, "(dht-r2hc-%D%(%p%))", ego->n, ego->cld);
+}
+
+static int applicable0(const problem *p_, const planner *plnr)
+{
+     const problem_rdft *p = (const problem_rdft *) p_;
+     return (1
+	     && !NO_DHT_R2HCP(plnr)
+	     && p->sz->rnk == 1
+	     && p->vecsz->rnk == 0
+	     && p->kind[0] == DHT
+	  );
+}
+
+static int applicable(const solver *ego, const problem *p, const planner *plnr)
+{
+     UNUSED(ego);
+     return (!NO_SLOWP(plnr) && applicable0(p, plnr));
+}
+
+static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr)
+{
+     P *pln;
+     const problem_rdft *p;
+     plan *cld;
+
+     static const plan_adt padt = {
+	  X(rdft_solve), awake, print, destroy
+     };
+
+     if (!applicable(ego_, p_, plnr))
+          return (plan *)0;
+
+     p = (const problem_rdft *) p_;
+
+     /* NO_DHT_R2HC stops infinite loops with rdft-dht.c */
+     cld = X(mkplan_f_d)(plnr, 
+			 X(mkproblem_rdft_1)(p->sz, p->vecsz, 
+					     p->I, p->O, R2HC),
+			 NO_DHT_R2HC, 0, 0);
+     if (!cld) return (plan *)0;
+
+     pln = MKPLAN_RDFT(P, &padt, apply);
+
+     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 += 4 * ((pln->n - 1)/2);
+     pln->super.super.ops.add += 2 * ((pln->n - 1)/2);
+
+     return &(pln->super.super);
+}
+
+/* constructor */
+static solver *mksolver(void)
+{
+     static const solver_adt sadt = { PROBLEM_RDFT, mkplan, 0 };
+     S *slv = MKSOLVER(S, &sadt);
+     return &(slv->super);
+}
+
+void X(dht_r2hc_register)(planner *p)
+{
+     REGISTER_SOLVER(p, mksolver());
+}