comparison src/fftw-3.3.3/rdft/hc2hc-generic.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
+ *
+ */
+
+/* express a hc2hc problem in terms of rdft + multiplication by
+   twiddle factors */
+
+#include "hc2hc.h"
+
+typedef hc2hc_solver S;
+
+typedef struct {
+     plan_hc2hc super;
+
+     INT r, m, s, vl, vs, mstart1, mcount1;
+     plan *cld0;
+     plan *cld;
+     twid *td;
+} P;
+
+
+/**************************************************************/
+static void mktwiddle(P *ego, enum wakefulness wakefulness)
+{
+     static const tw_instr tw[] = { { TW_HALF, 0, 0 }, { TW_NEXT, 1, 0 } };
+
+     /* note that R and M are swapped, to allow for sequential
+	access both to data and twiddles */
+     X(twiddle_awake)(wakefulness, &ego->td, tw, 
+		      ego->r * ego->m, ego->m, ego->r);
+}
+
+static void bytwiddle(const P *ego, R *IO, R sign)
+{
+     INT i, j, k;
+     INT r = ego->r, m = ego->m, s = ego->s, vl = ego->vl, vs = ego->vs;
+     INT ms = m * s;
+     INT mstart1 = ego->mstart1, mcount1 = ego->mcount1;
+     INT wrem = 2 * ((m-1)/2 - mcount1);
+
+     for (i = 0; i < vl; ++i, IO += vs) {
+	  const R *W = ego->td->W;
+
+	  A(m % 2 == 1);
+	  for (k = 1, W += (m - 1) + 2*(mstart1-1); k < r; ++k) {
+	       /* pr := IO + (j + mstart1) * s + k * ms */
+	       R *pr = IO + mstart1 * s + k * ms;
+
+	       /* pi := IO + (m - j - mstart1) * s + k * ms */
+	       R *pi = IO - mstart1 * s + (k + 1) * ms;
+
+	       for (j = 0; j < mcount1; ++j, pr += s, pi -= s) {
+		    E xr = *pr;
+		    E xi = *pi;
+		    E wr = W[0];
+		    E wi = sign * W[1];
+		    *pr = xr * wr - xi * wi;
+		    *pi = xi * wr + xr * wi;
+		    W += 2;
+	       }
+	       W += wrem;
+	  }
+     }
+}
+
+static void swapri(R *IO, INT r, INT m, INT s, INT jstart, INT jend)
+{
+     INT k;
+     INT ms = m * s;
+     INT js = jstart * s;
+     for (k = 0; k + k < r; ++k) {
+	  /* pr := IO + (m - j) * s + k * ms */
+	  R *pr = IO + (k + 1) * ms - js;
+	  /* pi := IO + (m - j) * s + (r - 1 - k) * ms */
+	  R *pi = IO + (r - k) * ms - js;
+	  INT j;
+	  for (j = jstart; j < jend; j += 1, pr -= s, pi -= s) {
+	       R t = *pr;
+	       *pr = *pi;
+	       *pi = t;
+	  }
+     }
+}
+
+static void reorder_dit(const P *ego, R *IO)
+{
+     INT i, k;
+     INT r = ego->r, m = ego->m, s = ego->s, vl = ego->vl, vs = ego->vs;
+     INT ms = m * s;
+     INT mstart1 = ego->mstart1, mend1 = mstart1 + ego->mcount1;
+
+     for (i = 0; i < vl; ++i, IO += vs) {
+	  for (k = 1; k + k < r; ++k) {
+	       R *p0 = IO + k * ms;
+	       R *p1 = IO + (r - k) * ms;
+	       INT j;
+
+	       for (j = mstart1; j < mend1; ++j) {
+		    E rp, ip, im, rm;
+		    rp = p0[j * s];
+		    im = p1[ms - j * s];
+		    rm = p1[j * s];
+		    ip = p0[ms - j * s];
+		    p0[j * s] = rp - im;
+		    p1[ms - j * s] = rp + im;
+		    p1[j * s] = rm - ip;
+		    p0[ms - j * s] = ip + rm;
+	       }
+	  }
+
+	  swapri(IO, r, m, s, mstart1, mend1);
+     }
+}
+
+static void reorder_dif(const P *ego, R *IO)
+{
+     INT i, k;
+     INT r = ego->r, m = ego->m, s = ego->s, vl = ego->vl, vs = ego->vs;
+     INT ms = m * s;
+     INT mstart1 = ego->mstart1, mend1 = mstart1 + ego->mcount1;
+
+     for (i = 0; i < vl; ++i, IO += vs) {
+	  swapri(IO, r, m, s, mstart1, mend1);
+
+	  for (k = 1; k + k < r; ++k) {
+	       R *p0 = IO + k * ms;
+	       R *p1 = IO + (r - k) * ms;
+	       const R half = K(0.5);
+	       INT j;
+
+	       for (j = mstart1; j < mend1; ++j) {
+		    E rp, ip, im, rm;
+		    rp = half * p0[j * s];
+		    im = half * p1[ms - j * s];
+		    rm = half * p1[j * s];
+		    ip = half * p0[ms - j * s];
+		    p0[j * s] = rp + im;
+		    p1[ms - j * s] = im - rp;
+		    p1[j * s] = rm + ip;
+		    p0[ms - j * s] = ip - rm;
+	       }
+	  }
+     }
+}
+
+static int applicable(rdft_kind kind, INT r, INT m, const planner *plnr)
+{
+     return (1 
+	     && (kind == R2HC || kind == HC2R)
+	     && (m % 2)
+	     && (r % 2)
+	     && !NO_SLOWP(plnr)
+	  );
+}
+
+/**************************************************************/
+
+static void apply_dit(const plan *ego_, R *IO)
+{
+     const P *ego = (const P *) ego_;
+     INT start;
+     plan_rdft *cld, *cld0;
+
+     bytwiddle(ego, IO, K(-1.0));
+
+     cld0 = (plan_rdft *) ego->cld0;
+     cld0->apply(ego->cld0, IO, IO);
+
+     start = ego->mstart1 * ego->s;
+     cld = (plan_rdft *) ego->cld;
+     cld->apply(ego->cld, IO + start, IO + start);
+
+     reorder_dit(ego, IO);
+}
+
+static void apply_dif(const plan *ego_, R *IO)
+{
+     const P *ego = (const P *) ego_;
+     INT start;
+     plan_rdft *cld, *cld0;
+
+     reorder_dif(ego, IO);
+
+     cld0 = (plan_rdft *) ego->cld0;
+     cld0->apply(ego->cld0, IO, IO);
+
+     start = ego->mstart1 * ego->s;
+     cld = (plan_rdft *) ego->cld;
+     cld->apply(ego->cld, IO + start, IO + start);
+
+     bytwiddle(ego, IO, K(1.0));
+}
+
+
+static void awake(plan *ego_, enum wakefulness wakefulness)
+{
+     P *ego = (P *) ego_;
+     X(plan_awake)(ego->cld0, wakefulness);
+     X(plan_awake)(ego->cld, wakefulness);
+     mktwiddle(ego, wakefulness);
+}
+
+static void destroy(plan *ego_)
+{
+     P *ego = (P *) ego_;
+     X(plan_destroy_internal)(ego->cld);
+     X(plan_destroy_internal)(ego->cld0);
+}
+
+static void print(const plan *ego_, printer *p)
+{
+     const P *ego = (const P *) ego_;
+     p->print(p, "(hc2hc-generic-%s-%D-%D%v%(%p%)%(%p%))", 
+	      ego->super.apply == apply_dit ? "dit" : "dif",
+	      ego->r, ego->m, ego->vl, ego->cld0, ego->cld);
+}
+
+static plan *mkcldw(const hc2hc_solver *ego_, 
+		    rdft_kind kind, INT r, INT m, INT s, INT vl, INT vs, 
+		    INT mstart, INT mcount,
+		    R *IO, planner *plnr)
+{
+     P *pln;
+     plan *cld0 = 0, *cld = 0;
+     INT mstart1, mcount1, mstride;
+
+     static const plan_adt padt = {
+	  0, awake, print, destroy
+     };
+
+     UNUSED(ego_);
+
+     A(mstart >= 0 && mcount > 0 && mstart + mcount <= (m+2)/2);
+
+     if (!applicable(kind, r, m, plnr))
+          return (plan *)0;
+
+     A(m % 2);
+     mstart1 = mstart + (mstart == 0);
+     mcount1 = mcount - (mstart == 0);
+     mstride = m - (mstart + mcount - 1) - mstart1;
+
+     /* 0th (DC) transform (vl of these), if mstart == 0 */
+     cld0 = X(mkplan_d)(plnr, 
+			X(mkproblem_rdft_1_d)(
+			     mstart == 0 ? X(mktensor_1d)(r, m * s, m * s)
+			     : X(mktensor_0d)(),
+			     X(mktensor_1d)(vl, vs, vs),
+			     IO, IO, kind)
+			);
+     if (!cld0) goto nada;
+
+     /* twiddle transforms: there are 2 x mcount1 x vl of these
+	(where 2 corresponds to the real and imaginary parts) ...
+        the 2 x mcount1 loops are combined if mstart=0 and mcount=(m+2)/2. */
+     cld = X(mkplan_d)(plnr, 
+			X(mkproblem_rdft_1_d)(
+			     X(mktensor_1d)(r, m * s, m * s),
+			     X(mktensor_3d)(2, mstride * s, mstride * s,
+					    mcount1, s, s, 
+					    vl, vs, vs),
+			     IO + s * mstart1, IO + s * mstart1, kind)
+	                );
+     if (!cld) goto nada;
+     
+     pln = MKPLAN_HC2HC(P, &padt, (kind == R2HC) ? apply_dit : apply_dif);
+     pln->cld = cld;
+     pln->cld0 = cld0;
+     pln->r = r;
+     pln->m = m;
+     pln->s = s;
+     pln->vl = vl;
+     pln->vs = vs;
+     pln->td = 0;
+     pln->mstart1 = mstart1;
+     pln->mcount1 = mcount1;
+
+     {
+	  double n0 = 0.5 * (r - 1) * (2 * mcount1) * vl;
+	  pln->super.super.ops = cld->ops;
+	  pln->super.super.ops.mul += (kind == R2HC ? 5.0 : 7.0) * n0;
+	  pln->super.super.ops.add += 4.0 * n0;
+	  pln->super.super.ops.other += 11.0 * n0;
+     }
+     return &(pln->super.super);
+
+ nada:
+     X(plan_destroy_internal)(cld);
+     X(plan_destroy_internal)(cld0);
+     return (plan *) 0;
+}
+
+static void regsolver(planner *plnr, INT r)
+{
+     S *slv = (S *)X(mksolver_hc2hc)(sizeof(S), r, mkcldw);
+     REGISTER_SOLVER(plnr, &(slv->super));
+     if (X(mksolver_hc2hc_hook)) {
+	  slv = (S *)X(mksolver_hc2hc_hook)(sizeof(S), r, mkcldw);
+	  REGISTER_SOLVER(plnr, &(slv->super));
+     }
+}
+
+void X(hc2hc_generic_register)(planner *p)
+{
+     regsolver(p, 0);
+}