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-rw-r--r--src/fftw3/rdft/rgeneric.c371
1 files changed, 371 insertions, 0 deletions
diff --git a/src/fftw3/rdft/rgeneric.c b/src/fftw3/rdft/rgeneric.c
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+++ b/src/fftw3/rdft/rgeneric.c
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+/*
+ * Copyright (c) 2003 Matteo Frigo
+ * Copyright (c) 2003 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include "rdft.h"
+
+typedef struct {
+ solver super;
+ rdft_kind kind;
+} S;
+
+typedef struct {
+ plan_rdft super;
+ plan *cld;
+ twid *td;
+ int os;
+ int r, m;
+ rdft_kind kind;
+} P;
+
+/***************************************************************************/
+
+static void apply_dit(const plan *ego_, R *I, R *O)
+{
+ const P *ego = (const P *) ego_;
+ int n, m, r;
+ int i, j, k;
+ int os, osm;
+ E *buf;
+ const R *W;
+ R *X, *YO, *YI;
+ E rsum, isum;
+ int wp, wincr;
+
+ {
+ plan_rdft *cld = (plan_rdft *) ego->cld;
+ cld->apply((plan *) cld, I, O);
+ }
+
+ r = ego->r;
+
+ STACK_MALLOC(E *, buf, r * 2 * sizeof(E));
+
+ osm = (m = ego->m) * (os = ego->os);
+ n = m * r;
+ W = ego->td->W;
+
+ X = O;
+ YO = O + r * osm;
+ YI = O + osm;
+
+ /* compute the transform of the r 0th elements (which are real) */
+ for (i = 0; i + i < r; ++i) {
+ rsum = K(0.0);
+ isum = K(0.0);
+ wincr = m * i;
+ for (j = 0, wp = 0; j < r; ++j) {
+ E tw_r = W[2*wp];
+ E tw_i = W[2*wp+1] ;
+ E re = X[j * osm];
+ rsum += re * tw_r;
+ isum += re * tw_i;
+ wp += wincr;
+ if (wp >= n)
+ wp -= n;
+ }
+ buf[2*i] = rsum;
+ buf[2*i+1] = isum;
+ }
+
+ /* store the transform back onto the A array */
+ X[0] = buf[0];
+ for (i = 1; i + i < r; ++i) {
+ X[i * osm] = buf[2*i];
+ YO[-i * osm] = buf[2*i+1];
+ }
+
+ X += os;
+ YI -= os;
+ YO -= os;
+
+ /* compute the transform of the middle elements (which are complex) */
+ for (k = 1; k + k < m; ++k, X += os, YI -= os, YO -= os) {
+ for (i = 0; i < r; ++i) {
+ rsum = K(0.0);
+ isum = K(0.0);
+ wincr = k + m * i;
+ for (j = 0, wp = 0; j < r; ++j) {
+ E tw_r = W[2*wp];
+ E tw_i = W[2*wp+1] ;
+ E re = X[j * osm];
+ E im = YI[j * osm];
+ rsum += re * tw_r - im * tw_i;
+ isum += re * tw_i + im * tw_r;
+ wp += wincr;
+ if (wp >= n)
+ wp -= n;
+ }
+ buf[2*i] = rsum;
+ buf[2*i+1] = isum;
+ }
+
+ /* store the transform back onto the A array */
+ for (i = 0; i + i < r; ++i) {
+ X[i * osm] = buf[2*i];
+ YO[-i * osm] = buf[2*i+1];
+ }
+ for (; i < r; ++i) {
+ X[i * osm] = -buf[2*i+1];
+ YO[-i * osm] = buf[2*i];
+ }
+ }
+
+ /* no final element, since m is odd */
+
+ STACK_FREE(buf);
+}
+
+static void apply_dif(const plan *ego_, R *I, R *O)
+{
+ const P *ego = (const P *) ego_;
+ int n, m, r;
+ int i, j, k;
+ int is, ism;
+ E *buf;
+ const R *W;
+ R *X, *YO, *YI;
+ E rsum, isum;
+ int wp, wincr;
+
+ r = ego->r;
+
+ STACK_MALLOC(E *, buf, r * 2 * sizeof(E));
+
+ ism = (m = ego->m) * (is = ego->os);
+ n = m * r;
+ W = ego->td->W;
+
+ X = I;
+ YI = I + r * ism;
+ YO = I + ism;
+
+ /*
+ * compute the transform of the r 0th elements (which are halfcomplex)
+ * yielding real numbers
+ */
+ /* copy the input into the temporary array */
+ buf[0] = X[0];
+ for (i = 1; i + i < r; ++i) {
+ buf[2*i] = X[i * ism];
+ buf[2*i+1] = YI[-i * ism];
+ }
+
+ for (i = 0; i < r; ++i) {
+ rsum = K(0.0);
+ wincr = m * i;
+ for (j = 1, wp = wincr; j + j < r; ++j) {
+ E tw_r = W[2*wp];
+ E tw_i = W[2*wp+1];
+ E re = buf[2*j];
+ E im = buf[2*j+1];
+ rsum += re * tw_r + im * tw_i;
+ wp += wincr;
+ if (wp >= n)
+ wp -= n;
+ }
+ X[i * ism] = K(2.0) * rsum + buf[0];
+ }
+
+ X += is;
+ YI -= is;
+ YO -= is;
+
+ /* compute the transform of the middle elements (which are complex) */
+ for (k = 1; k + k < m; ++k, X += is, YI -= is, YO -= is) {
+ /* copy the input into the temporary array */
+ for (i = 0; i + i < r; ++i) {
+ buf[2*i] = X[i * ism];
+ buf[2*i+1] = YI[-i * ism];
+ }
+ for (; i < r; ++i) {
+ buf[2*i+1] = -X[i * ism];
+ buf[2*i] = YI[-i * ism];
+ }
+
+ for (i = 0; i < r; ++i) {
+ rsum = K(0.0);
+ isum = K(0.0);
+ wincr = m * i;
+ for (j = 0, wp = k * i; j < r; ++j) {
+ E tw_r = W[2*wp];
+ E tw_i = W[2*wp+1];
+ E re = buf[2*j];
+ E im = buf[2*j+1];
+ rsum += re * tw_r + im * tw_i;
+ isum += im * tw_r - re * tw_i;
+ wp += wincr;
+ if (wp >= n)
+ wp -= n;
+ }
+ X[i * ism] = rsum;
+ YO[i * ism] = isum;
+ }
+ }
+
+ /* no final element, since m is odd */
+
+ STACK_FREE(buf);
+
+ {
+ plan_rdft *cld = (plan_rdft *) ego->cld;
+ cld->apply((plan *) cld, I, O);
+ }
+
+}
+
+/***************************************************************************/
+
+static void awake(plan *ego_, int flg)
+{
+ P *ego = (P *) ego_;
+ static const tw_instr generic_tw[] = {
+ { TW_GENERIC, 0, 0 },
+ { TW_NEXT, 1, 0 }
+ };
+
+ AWAKE(ego->cld, flg);
+ /* FIXME: can we get away with fewer twiddles? */
+ X(twiddle_awake)(flg, &ego->td, generic_tw,
+ ego->r * ego->m, ego->r, ego->m);
+}
+
+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, "(rdft-generic-%s-%d%(%p%))",
+ ego->kind == R2HC ? "r2hc-dit" : "hc2r-dif",
+ ego->r, ego->cld);
+}
+
+static int applicable0(const solver *ego_, const problem *p_)
+{
+ if (RDFTP(p_)) {
+ const S *ego = (const S *) ego_;
+ const problem_rdft *p = (const problem_rdft *) p_;
+ return (1
+ && p->sz->rnk == 1
+ && p->vecsz->rnk == 0
+ && p->sz->dims[0].n > 1
+ && p->sz->dims[0].n % 2 /* ensure r and n/r odd */
+ && p->kind[0] == ego->kind
+ );
+ }
+
+ return 0;
+}
+
+static int applicable(const solver *ego_, const problem *p_,
+ const planner *plnr)
+{
+ if (NO_UGLYP(plnr)) return 0; /* always ugly */
+ if (!applicable0(ego_, p_)) return 0;
+
+ if (NO_LARGE_GENERICP(plnr)) {
+ const problem_rdft *p = (const problem_rdft *) p_;
+ if (X(first_divisor)(p->sz->dims[0].n) >= GENERIC_MIN_BAD) return 0;
+ }
+ return 1;
+}
+
+static plan *mkplan(const solver *ego, const problem *p_, planner *plnr)
+{
+ const problem_rdft *p = (const problem_rdft *) p_;
+ P *pln = 0;
+ int n, r, m;
+ int is, os;
+ plan *cld = (plan *) 0;
+ problem *cldp;
+
+ static const plan_adt padt = {
+ X(rdft_solve), awake, print, destroy
+ };
+
+ if (!applicable(ego, p_, plnr))
+ goto nada;
+
+ n = p->sz->dims[0].n;
+ is = p->sz->dims[0].is;
+ os = p->sz->dims[0].os;
+
+ r = X(first_divisor)(n);
+ m = n / r;
+
+ if (R2HC_KINDP(p->kind[0])) {
+ cldp = X(mkproblem_rdft_d)(X(mktensor_1d)(m, r * is, os),
+ X(mktensor_1d)(r, is, m * os),
+ p->I, p->O, p->kind);
+ }
+ else {
+ cldp = X(mkproblem_rdft_d)(X(mktensor_1d)(m, is, r * os),
+ X(mktensor_1d)(r, m * is, os),
+ p->I, p->O, p->kind);
+ }
+ if (!(cld = X(mkplan_d)(plnr, cldp))) goto nada;
+
+ pln = MKPLAN_RDFT(P, &padt, R2HC_KINDP(p->kind[0]) ? apply_dit:apply_dif);
+
+ pln->os = R2HC_KINDP(p->kind[0]) ? os : is;
+ pln->r = r;
+ pln->m = m;
+ pln->cld = cld;
+ pln->td = 0;
+ pln->kind = p->kind[0];
+
+ X(ops_zero)(&pln->super.super.ops);
+ pln->super.super.ops.add = 4 * r * r;
+ pln->super.super.ops.mul = 4 * r * r;
+ /* loads + stores, minus loads + stores for all DIT codelets */
+ pln->super.super.ops.other = 4 * r + 4 * r * r - (6*r - 2);
+ X(ops_madd)((m - 1)/2, &pln->super.super.ops, &cld->ops,
+ &pln->super.super.ops);
+ pln->super.super.ops.add += 2 * r * r;
+ pln->super.super.ops.mul += 2 * r * r;
+ pln->super.super.ops.other += 3 * r + 3 * r * r - 2*r;
+
+ return &(pln->super.super);
+
+ nada:
+ X(plan_destroy_internal)(cld);
+ X(ifree0)(pln);
+ return (plan *) 0;
+}
+
+/* constructors */
+
+static solver *mksolver(rdft_kind kind)
+{
+ static const solver_adt sadt = { mkplan };
+ 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));
+}
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