comparison src/fftw-3.3.8/rdft/dft-r2hc.c @ 167:bd3cc4d1df30

Add FFTW 3.3.8 source, and a Linux build

+/*
+ * 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
+ *
+ */
+
+
+/* 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/rdft.h"
+#include "dft/dft.h"
+
+typedef struct {
+     solver super;
+} S;
+
+typedef struct {
+     plan_dft super;
+     plan *cld;
+     INT ishift, oshift;
+     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 n;
+
+     UNUSED(ii);
+
+     { /* transform vector of real & imag parts: */
+	  plan_rdft *cld = (plan_rdft *) ego->cld;
+	  cld->apply((plan *) cld, ri + ego->ishift, ro + ego->oshift);
+     }
+
+     n = ego->n;
+     if (n > 1) {
+	  INT i, os = ego->os;
+	  for (i = 1; i < (n + 1)/2; ++i) {
+	       E 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_, 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, "(dft-r2hc-%D%(%p%))", ego->n, ego->cld);
+}
+
+
+static int applicable0(const problem *p_)
+{
+     const problem_dft *p = (const problem_dft *) p_;
+     return ((p->sz->rnk == 1 && p->vecsz->rnk == 0)
+	     || (p->sz->rnk == 0 && FINITE_RNK(p->vecsz->rnk))
+	  );
+}
+
+static int splitp(R *r, R *i, INT n, INT s)
+{
+     return ((r > i ? (r - i) : (i - r)) >= n * (s > 0 ? s : 0-s));
+}
+
+static int applicable(const problem *p_, const planner *plnr)
+{
+     if (!applicable0(p_)) return 0;
+
+     {
+	  const problem_dft *p = (const problem_dft *) p_;
+
+	  /* rank-0 problems are always OK */
+	  if (p->sz->rnk == 0) return 1;
+
+	  /* this solver is ok for split arrays */
+	  if (p->sz->rnk == 1 &&
+	      splitp(p->ri, p->ii, p->sz->dims[0].n, p->sz->dims[0].is) &&
+	      splitp(p->ro, p->io, p->sz->dims[0].n, p->sz->dims[0].os))
+	       return 1;
+
+	  return !(NO_DFT_R2HCP(plnr));
+     }
+}
+
+static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr)
+{
+     P *pln;
+     const problem_dft *p;
+     plan *cld;
+     INT ishift = 0, oshift = 0;
+
+     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);
+	  int i;
+	  for (i = 0; i < cld_vec->rnk; ++i) { /* make all istrides > 0 */
+	       if (cld_vec->dims[i].is < 0) {
+		    INT nm1 = cld_vec->dims[i].n - 1;
+		    ishift -= nm1 * (cld_vec->dims[i].is *= -1);
+		    oshift -= nm1 * (cld_vec->dims[i].os *= -1);
+	       }
+	  }
+	  cld = X(mkplan_d)(plnr, 
+			    X(mkproblem_rdft_1)(p->sz, cld_vec, 
+						p->ri + ishift, 
+						p->ro + oshift, R2HC));
+	  X(tensor_destroy2)(ri_vec, cld_vec);
+     }
+     if (!cld) return (plan *)0;
+
+     pln = MKPLAN_DFT(P, &padt, apply);
+
+     if (p->sz->rnk == 0) {
+	  pln->n = 1;
+	  pln->os = 0;
+     }
+     else {
+	  pln->n = p->sz->dims[0].n;
+	  pln->os = p->sz->dims[0].os;
+     }
+     pln->ishift = ishift;
+     pln->oshift = oshift;
+
+     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);
+     pln->super.super.ops.other += 1; /* estimator hack for nop plans */
+
+     return &(pln->super.super);
+}
+
+/* constructor */
+static solver *mksolver(void)
+{
+     static const solver_adt sadt = { PROBLEM_DFT, mkplan, 0 };
+     S *slv = MKSOLVER(S, &sadt);
+     return &(slv->super);
+}
+
+void X(dft_r2hc_register)(planner *p)
+{
+     REGISTER_SOLVER(p, mksolver());
+}