comparison src/fftw-3.3.8/rdft/generic.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
+ *
+ */
+
+#include "rdft/rdft.h"
+
+typedef struct {
+     solver super;
+     rdft_kind kind;
+} S;
+
+typedef struct {
+     plan_rdft super;
+     twid *td;
+     INT n, is, os;
+     rdft_kind kind;
+} P;
+
+/***************************************************************************/
+
+static void cdot_r2hc(INT n, const E *x, const R *w, R *or0, R *oi1)
+{
+     INT i;
+
+     E rr = x[0], ri = 0;
+     x += 1;
+     for (i = 1; i + i < n; ++i) {
+	  rr += x[0] * w[0];
+	  ri += x[1] * w[1];
+	  x += 2; w += 2;
+     }
+     *or0 = rr;
+     *oi1 = ri;
+}
+
+static void hartley_r2hc(INT n, const R *xr, INT xs, E *o, R *pr)
+{
+     INT i;
+     E sr;
+     o[0] = sr = xr[0]; o += 1;
+     for (i = 1; i + i < n; ++i) {
+	  R a, b;
+	  a = xr[i * xs];
+	  b =  xr[(n - i) * xs];
+	  sr += (o[0] = a + b);
+#if FFT_SIGN == -1
+	  o[1] = b - a;
+#else
+	  o[1] = a - b;
+#endif
+	  o += 2;
+     }
+     *pr = sr;
+}
+		    
+static void apply_r2hc(const plan *ego_, R *I, R *O)
+{
+     const P *ego = (const P *) ego_;
+     INT i;
+     INT n = ego->n, is = ego->is, os = ego->os;
+     const R *W = ego->td->W;
+     E *buf;
+     size_t bufsz = n * sizeof(E);
+
+     BUF_ALLOC(E *, buf, bufsz);
+     hartley_r2hc(n, I, is, buf, O);
+
+     for (i = 1; i + i < n; ++i) {
+	  cdot_r2hc(n, buf, W, O + i * os, O + (n - i) * os);
+	  W += n - 1;
+     }
+
+     BUF_FREE(buf, bufsz);
+}
+
+
+static void cdot_hc2r(INT n, const E *x, const R *w, R *or0, R *or1)
+{
+     INT i;
+
+     E rr = x[0], ii = 0; 
+     x += 1;
+     for (i = 1; i + i < n; ++i) {
+	  rr += x[0] * w[0];
+	  ii += x[1] * w[1];
+	  x += 2; w += 2;
+     }
+#if FFT_SIGN == -1
+     *or0 = rr - ii;
+     *or1 = rr + ii;
+#else
+     *or0 = rr + ii;
+     *or1 = rr - ii;
+#endif
+}
+
+static void hartley_hc2r(INT n, const R *x, INT xs, E *o, R *pr)
+{
+     INT i;
+     E sr;
+
+     o[0] = sr = x[0]; o += 1;
+     for (i = 1; i + i < n; ++i) {
+	  sr += (o[0] = x[i * xs] + x[i * xs]);
+	  o[1] = x[(n - i) * xs] + x[(n - i) * xs];
+	  o += 2;
+     }
+     *pr = sr;
+}
+
+static void apply_hc2r(const plan *ego_, R *I, R *O)		    
+{
+     const P *ego = (const P *) ego_;
+     INT i;
+     INT n = ego->n, is = ego->is, os = ego->os;
+     const R *W = ego->td->W;
+     E *buf;
+     size_t bufsz = n * sizeof(E);
+
+     BUF_ALLOC(E *, buf, bufsz);
+     hartley_hc2r(n, I, is, buf, O);
+
+     for (i = 1; i + i < n; ++i) {
+	  cdot_hc2r(n, buf, W, O + i * os, O + (n - i) * os);
+	  W += n - 1;
+     }
+
+     BUF_FREE(buf, bufsz);
+}
+
+
+/***************************************************************************/
+
+static void awake(plan *ego_, enum wakefulness wakefulness)
+{
+     P *ego = (P *) ego_;
+     static const tw_instr half_tw[] = {
+	  { TW_HALF, 1, 0 },
+	  { TW_NEXT, 1, 0 }
+     };
+
+     X(twiddle_awake)(wakefulness, &ego->td, half_tw, ego->n, ego->n,
+		      (ego->n - 1) / 2);
+}
+
+static void print(const plan *ego_, printer *p)
+{
+     const P *ego = (const P *) ego_;
+
+     p->print(p, "(rdft-generic-%s-%D)", 
+	      ego->kind == R2HC ? "r2hc" : "hc2r", 
+	      ego->n);
+}
+
+static int applicable(const S *ego, const problem *p_, 
+		      const planner *plnr)
+{
+     const problem_rdft *p = (const problem_rdft *) p_;
+     return (1
+	     && p->sz->rnk == 1
+	     && p->vecsz->rnk == 0
+	     && (p->sz->dims[0].n % 2) == 1 
+	     && CIMPLIES(NO_LARGE_GENERICP(plnr), p->sz->dims[0].n < GENERIC_MIN_BAD)
+	     && CIMPLIES(NO_SLOWP(plnr), p->sz->dims[0].n > GENERIC_MAX_SLOW)
+	     && X(is_prime)(p->sz->dims[0].n)
+	     && p->kind[0] == ego->kind
+	  );
+}
+
+static plan *mkplan(const solver *ego_, const problem *p_, planner *plnr)
+{
+     const S *ego = (const S *)ego_;
+     const problem_rdft *p;
+     P *pln;
+     INT n;
+
+     static const plan_adt padt = {
+	  X(rdft_solve), awake, print, X(plan_null_destroy)
+     };
+
+     if (!applicable(ego, p_, plnr))
+          return (plan *)0;
+
+     p = (const problem_rdft *) p_;
+     pln = MKPLAN_RDFT(P, &padt, 
+		       R2HC_KINDP(p->kind[0]) ? apply_r2hc : apply_hc2r);
+
+     pln->n = n = p->sz->dims[0].n;
+     pln->is = p->sz->dims[0].is;
+     pln->os = p->sz->dims[0].os;
+     pln->td = 0;
+     pln->kind = ego->kind;
+
+     pln->super.super.ops.add = (n-1) * 2.5;
+     pln->super.super.ops.mul = 0;
+     pln->super.super.ops.fma = 0.5 * (n-1) * (n-1) ;
+#if 0 /* these are nice pipelined sequential loads and should cost nothing */
+     pln->super.super.ops.other = (n-1)*(2 + 1 + (n-1));  /* approximate */
+#endif
+
+     return &(pln->super.super);
+}
+
+static solver *mksolver(rdft_kind kind)
+{
+     static const solver_adt sadt = { PROBLEM_RDFT, mkplan, 0 };
+     S *slv = MKSOLVER(S, &sadt);
+     slv->kind = kind;
+     return &(slv->super);
+}
+
+void X(rdft_generic_register)(planner *p)
+{
+     REGISTER_SOLVER(p, mksolver(R2HC));
+     REGISTER_SOLVER(p, mksolver(HC2R));
+}