comparison src/fftw-3.3.3/libbench2/verify-r2r.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
+ *
+ */
+
+/* Lots of ugly duplication from verify-lib.c, plus lots of ugliness in
+   general for all of the r2r variants...oh well, for now */
+
+#include "verify.h"
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+typedef struct {
+     bench_problem *p;
+     bench_tensor *probsz;
+     bench_tensor *totalsz;
+     bench_tensor *pckdsz;
+     bench_tensor *pckdvecsz;
+} info;
+
+/*
+ * Utility functions:
+ */
+
+static double dabs(double x) { return (x < 0.0) ? -x : x; }
+static double dmin(double x, double y) { return (x < y) ? x : y; }
+
+static double raerror(R *a, R *b, int n)
+{
+     if (n > 0) {
+          /* compute the relative Linf error */
+          double e = 0.0, mag = 0.0;
+          int i;
+
+          for (i = 0; i < n; ++i) {
+               e = dmax(e, dabs(a[i] - b[i]));
+               mag = dmax(mag, dmin(dabs(a[i]), dabs(b[i])));
+          }
+	  if (dabs(mag) < 1e-14 && dabs(e) < 1e-14)
+	       e = 0.0;
+	  else
+	       e /= mag;
+
+#ifdef HAVE_ISNAN
+          BENCH_ASSERT(!isnan(e));
+#endif
+          return e;
+     } else
+          return 0.0;
+}
+
+#define by2pi(m, n) ((K2PI * (m)) / (n))
+
+/*
+ * Improve accuracy by reducing x to range [0..1/8]
+ * before multiplication by 2 * PI.
+ */
+
+static trigreal bench_sincos(trigreal m, trigreal n, int sinp)
+{
+     /* waiting for C to get tail recursion... */
+     trigreal half_n = n * 0.5;
+     trigreal quarter_n = half_n * 0.5;
+     trigreal eighth_n = quarter_n * 0.5;
+     trigreal sgn = 1.0;
+
+     if (sinp) goto sin;
+ cos:
+     if (m < 0) { m = -m; /* goto cos; */ }
+     if (m > half_n) { m = n - m; goto cos; }
+     if (m > eighth_n) { m = quarter_n - m; goto sin; }
+     return sgn * COS(by2pi(m, n));
+
+ msin:
+     sgn = -sgn;
+ sin:
+     if (m < 0) { m = -m; goto msin; }
+     if (m > half_n) { m = n - m; goto msin; }
+     if (m > eighth_n) { m = quarter_n - m; goto cos; }
+     return sgn * SIN(by2pi(m, n));
+}
+
+static trigreal cos2pi(int m, int n)
+{
+     return bench_sincos((trigreal)m, (trigreal)n, 0);
+}
+
+static trigreal sin2pi(int m, int n)
+{
+     return bench_sincos((trigreal)m, (trigreal)n, 1);
+}
+
+static trigreal cos00(int i, int j, int n)
+{
+     return cos2pi(i * j, n);
+}
+
+static trigreal cos01(int i, int j, int n)
+{
+     return cos00(i, 2*j + 1, 2*n);
+}
+
+static trigreal cos10(int i, int j, int n)
+{
+     return cos00(2*i + 1, j, 2*n);
+}
+
+static trigreal cos11(int i, int j, int n)
+{
+     return cos00(2*i + 1, 2*j + 1, 4*n);
+}
+
+static trigreal sin00(int i, int j, int n)
+{
+     return sin2pi(i * j, n);
+}
+
+static trigreal sin01(int i, int j, int n)
+{
+     return sin00(i, 2*j + 1, 2*n);
+}
+
+static trigreal sin10(int i, int j, int n)
+{
+     return sin00(2*i + 1, j, 2*n);
+}
+
+static trigreal sin11(int i, int j, int n)
+{
+     return sin00(2*i + 1, 2*j + 1, 4*n);
+}
+
+static trigreal realhalf(int i, int j, int n)
+{
+     UNUSED(i);
+     if (j <= n - j)
+	  return 1.0;
+     else
+	  return 0.0;
+}
+
+static trigreal coshalf(int i, int j, int n)
+{
+     if (j <= n - j)
+	  return cos00(i, j, n);
+     else
+	  return cos00(i, n - j, n);
+}
+
+static trigreal unity(int i, int j, int n)
+{
+     UNUSED(i);
+     UNUSED(j);
+     UNUSED(n);
+     return 1.0;
+}
+
+typedef trigreal (*trigfun)(int, int, int);
+
+static void rarand(R *a, int n)
+{
+     int i;
+
+     /* generate random inputs */
+     for (i = 0; i < n; ++i) {
+	  a[i] = mydrand();
+     }
+}
+
+/* C = A + B */
+static void raadd(R *c, R *a, R *b, int n)
+{
+     int i;
+
+     for (i = 0; i < n; ++i) {
+	  c[i] = a[i] + b[i];
+     }
+}
+
+/* C = A - B */
+static void rasub(R *c, R *a, R *b, int n)
+{
+     int i;
+
+     for (i = 0; i < n; ++i) {
+	  c[i] = a[i] - b[i];
+     }
+}
+
+/* B = rotate left A + rotate right A */
+static void rarolr(R *b, R *a, int n, int nb, int na, 
+		   r2r_kind_t k)
+{
+     int isL0 = 0, isL1 = 0, isR0 = 0, isR1 = 0;
+     int i, ib, ia;
+
+     for (ib = 0; ib < nb; ++ib) {
+	  for (i = 0; i < n - 1; ++i)
+	       for (ia = 0; ia < na; ++ia)
+		    b[(ib * n + i) * na + ia] =
+			 a[(ib * n + i + 1) * na + ia];
+
+	  /* ugly switch to do boundary conditions for various r2r types */
+	  switch (k) {
+	       /* periodic boundaries */
+	      case R2R_DHT:
+	      case R2R_R2HC:
+		   for (ia = 0; ia < na; ++ia) {
+			b[(ib * n + n - 1) * na + ia] = 
+			     a[(ib * n + 0) * na + ia];
+			b[(ib * n + 0) * na + ia] += 
+			     a[(ib * n + n - 1) * na + ia];
+		   }
+		   break;
+		   
+	      case R2R_HC2R: /* ugh (hermitian halfcomplex boundaries) */
+		   if (n > 2) {
+			if (n % 2 == 0)
+			     for (ia = 0; ia < na; ++ia) {
+				  b[(ib * n + n - 1) * na + ia] = 0.0;
+				  b[(ib * n + 0) * na + ia] += 
+				       a[(ib * n + 1) * na + ia];
+				  b[(ib * n + n/2) * na + ia] += 
+				       + a[(ib * n + n/2 - 1) * na + ia]
+				       - a[(ib * n + n/2 + 1) * na + ia];
+				  b[(ib * n + n/2 + 1) * na + ia] += 
+				       - a[(ib * n + n/2) * na + ia];
+			     }
+			else 
+			     for (ia = 0; ia < na; ++ia) {
+				  b[(ib * n + n - 1) * na + ia] = 0.0;
+				  b[(ib * n + 0) * na + ia] += 
+				       a[(ib * n + 1) * na + ia];
+				  b[(ib * n + n/2) * na + ia] += 
+				       + a[(ib * n + n/2) * na + ia]
+				       - a[(ib * n + n/2 + 1) * na + ia];
+				  b[(ib * n + n/2 + 1) * na + ia] += 
+				       - a[(ib * n + n/2 + 1) * na + ia]
+				       - a[(ib * n + n/2) * na + ia];
+			     }
+		   } else /* n <= 2 */ {
+			for (ia = 0; ia < na; ++ia) {
+			     b[(ib * n + n - 1) * na + ia] =
+				  a[(ib * n + 0) * na + ia];
+			     b[(ib * n + 0) * na + ia] += 
+				  a[(ib * n + n - 1) * na + ia];
+			}
+		   }
+		   break;
+		   
+	      /* various even/odd boundary conditions */
+	      case R2R_REDFT00:
+		   isL1 = isR1 = 1;
+		   goto mirrors;
+	      case R2R_REDFT01:
+		   isL1 = 1;
+		   goto mirrors;
+	      case R2R_REDFT10:
+		   isL0 = isR0 = 1;
+		   goto mirrors;
+	      case R2R_REDFT11:
+		   isL0 = 1;
+		   isR0 = -1;
+		   goto mirrors;
+	      case R2R_RODFT00:
+		   goto mirrors;
+	      case R2R_RODFT01:
+		   isR1 = 1;
+		   goto mirrors;
+	      case R2R_RODFT10:
+		   isL0 = isR0 = -1;
+		   goto mirrors;
+	      case R2R_RODFT11:
+		   isL0 = -1;
+		   isR0 = 1;
+		   goto mirrors;
+
+	  mirrors:
+		   
+		   for (ia = 0; ia < na; ++ia)
+			b[(ib * n + n - 1) * na + ia] = 
+			     isR0 * a[(ib * n + n - 1) * na + ia]
+			     + (n > 1 ? isR1 * a[(ib * n + n - 2) * na + ia]
+				: 0);
+		   
+		   for (ia = 0; ia < na; ++ia)
+			b[(ib * n) * na + ia] += 
+			     isL0 * a[(ib * n) * na + ia]
+			     + (n > 1 ? isL1 * a[(ib * n + 1) * na + ia] : 0);
+		   
+	  }
+
+	  for (i = 1; i < n; ++i)
+	       for (ia = 0; ia < na; ++ia)
+		    b[(ib * n + i) * na + ia] +=
+			 a[(ib * n + i - 1) * na + ia];
+     }
+}
+
+static void raphase_shift(R *b, R *a, int n, int nb, int na,
+			 int n0, int k0, trigfun t)
+{
+     int j, jb, ja;
+ 
+     for (jb = 0; jb < nb; ++jb)
+          for (j = 0; j < n; ++j) {
+               trigreal c = 2.0 * t(1, j + k0, n0);
+
+               for (ja = 0; ja < na; ++ja) {
+                    int k = (jb * n + j) * na + ja;
+                    b[k] = a[k] * c;
+               }
+          }
+}
+
+/* A = alpha * A  (real, in place) */
+static void rascale(R *a, R alpha, int n)
+{
+     int i;
+
+     for (i = 0; i < n; ++i) {
+	  a[i] *= alpha;
+     }
+}
+
+/*
+ * compute rdft:
+ */
+
+/* copy real A into real B, using output stride of A and input stride of B */
+typedef struct {
+     dotens2_closure k;
+     R *ra;
+     R *rb;
+} cpyr_closure;
+
+static void cpyr0(dotens2_closure *k_, 
+		  int indxa, int ondxa, int indxb, int ondxb)
+{
+     cpyr_closure *k = (cpyr_closure *)k_;
+     k->rb[indxb] = k->ra[ondxa];
+     UNUSED(indxa); UNUSED(ondxb);
+}
+
+static void cpyr(R *ra, bench_tensor *sza, R *rb, bench_tensor *szb)
+{
+     cpyr_closure k;
+     k.k.apply = cpyr0;
+     k.ra = ra; k.rb = rb;
+     bench_dotens2(sza, szb, &k.k);
+}
+
+static void dofft(info *nfo, R *in, R *out)
+{
+     cpyr(in, nfo->pckdsz, (R *) nfo->p->in, nfo->totalsz);
+     after_problem_rcopy_from(nfo->p, (bench_real *)nfo->p->in);
+     doit(1, nfo->p);
+     after_problem_rcopy_to(nfo->p, (bench_real *)nfo->p->out);
+     cpyr((R *) nfo->p->out, nfo->totalsz, out, nfo->pckdsz);
+}
+
+static double racmp(R *a, R *b, int n, const char *test, double tol)
+{
+     double d = raerror(a, b, n);
+     if (d > tol) {
+	  ovtpvt_err("Found relative error %e (%s)\n", d, test);
+	  {
+	       int i, N;
+	       N = n > 300 && verbose <= 2 ? 300 : n;
+	       for (i = 0; i < N; ++i)
+		    ovtpvt_err("%8d %16.12f   %16.12f\n", i, 
+			       (double) a[i],
+			       (double) b[i]);
+	  }
+	  bench_exit(EXIT_FAILURE);
+     }
+     return d;
+}
+
+/***********************************************************************/
+
+typedef struct {
+     int n; /* physical size */
+     int n0; /* "logical" transform size */
+     int i0, k0; /* shifts of input/output */
+     trigfun ti, ts;  /* impulse/shift trig functions */
+} dim_stuff;
+
+static void impulse_response(int rnk, dim_stuff *d, R impulse_amp,
+			     R *A, int N)
+{
+     if (rnk == 0)
+	  A[0] = impulse_amp;
+     else {
+	  int i;
+	  N /= d->n;
+	  for (i = 0; i < d->n; ++i) {
+	       impulse_response(rnk - 1, d + 1,
+				impulse_amp * d->ti(d->i0, d->k0 + i, d->n0),
+				A + i * N, N);
+	  }
+     }
+}
+
+/***************************************************************************/
+
+/*
+ * Implementation of the FFT tester described in
+ *
+ * Funda Ergün. Testing multivariate linear functions: Overcoming the
+ * generator bottleneck. In Proceedings of the Twenty-Seventh Annual
+ * ACM Symposium on the Theory of Computing, pages 407-416, Las Vegas,
+ * Nevada, 29 May--1 June 1995.
+ *
+ * Also: F. Ergun, S. R. Kumar, and D. Sivakumar, "Self-testing without
+ * the generator bottleneck," SIAM J. on Computing 29 (5), 1630-51 (2000).
+ */
+
+static double rlinear(int n, info *nfo, R *inA, R *inB, R *inC, R *outA,
+		      R *outB, R *outC, R *tmp, int rounds, double tol)
+{
+     double e = 0.0;
+     int j;
+
+     for (j = 0; j < rounds; ++j) {
+	  R alpha, beta;
+	  alpha = mydrand();
+	  beta = mydrand();
+	  rarand(inA, n);
+	  rarand(inB, n);
+	  dofft(nfo, inA, outA);
+	  dofft(nfo, inB, outB);
+
+	  rascale(outA, alpha, n);
+	  rascale(outB, beta, n);
+	  raadd(tmp, outA, outB, n);
+	  rascale(inA, alpha, n);
+	  rascale(inB, beta, n);
+	  raadd(inC, inA, inB, n);
+	  dofft(nfo, inC, outC);
+
+	  e = dmax(e, racmp(outC, tmp, n, "linear", tol));
+     }
+     return e;
+}
+
+static double rimpulse(dim_stuff *d, R impulse_amp,
+		       int n, int vecn, info *nfo, 
+		       R *inA, R *inB, R *inC,
+		       R *outA, R *outB, R *outC,
+		       R *tmp, int rounds, double tol)
+{
+     double e = 0.0;
+     int N = n * vecn;
+     int i;
+     int j;
+
+     /* test 2: check that the unit impulse is transformed properly */
+
+     for (i = 0; i < N; ++i) {
+	  /* pls */
+	  inA[i] = 0.0;
+     }
+     for (i = 0; i < vecn; ++i) {
+	  inA[i * n] = (i+1) / (double)(vecn+1);
+     
+	  /* transform of the pls */
+	  impulse_response(nfo->probsz->rnk, d, impulse_amp * inA[i * n],
+			   outA + i * n, n);
+     }
+
+     dofft(nfo, inA, tmp);
+     e = dmax(e, racmp(tmp, outA, N, "impulse 1", tol));
+
+     for (j = 0; j < rounds; ++j) {
+          rarand(inB, N);
+          rasub(inC, inA, inB, N);
+          dofft(nfo, inB, outB);
+          dofft(nfo, inC, outC);
+          raadd(tmp, outB, outC, N);
+          e = dmax(e, racmp(tmp, outA, N, "impulse", tol));
+     }
+     return e;
+}
+
+static double t_shift(int n, int vecn, info *nfo, 
+		      R *inA, R *inB, R *outA, R *outB, R *tmp,
+		      int rounds, double tol,
+		      dim_stuff *d)
+{
+     double e = 0.0;
+     int nb, na, dim, N = n * vecn;
+     int i, j;
+     bench_tensor *sz = nfo->probsz;
+
+     /* test 3: check the time-shift property */
+     /* the paper performs more tests, but this code should be fine too */
+
+     nb = 1;
+     na = n;
+
+     /* check shifts across all SZ dimensions */
+     for (dim = 0; dim < sz->rnk; ++dim) {
+	  int ncur = sz->dims[dim].n;
+
+	  na /= ncur;
+
+	  for (j = 0; j < rounds; ++j) {
+	       rarand(inA, N);
+
+	       for (i = 0; i < vecn; ++i) {
+		    rarolr(inB + i * n, inA + i*n, ncur, nb,na, 
+			  nfo->p->k[dim]);
+	       }
+	       dofft(nfo, inA, outA);
+	       dofft(nfo, inB, outB);
+	       for (i = 0; i < vecn; ++i) 
+		    raphase_shift(tmp + i * n, outA + i * n, ncur, 
+				 nb, na, d[dim].n0, d[dim].k0, d[dim].ts);
+	       e = dmax(e, racmp(tmp, outB, N, "time shift", tol));
+	  }
+
+	  nb *= ncur;
+     }
+     return e;
+}
+
+/***********************************************************************/
+
+void verify_r2r(bench_problem *p, int rounds, double tol, errors *e)
+{
+     R *inA, *inB, *inC, *outA, *outB, *outC, *tmp;
+     info nfo;
+     int n, vecn, N;
+     double impulse_amp = 1.0;
+     dim_stuff *d;
+     int i;
+
+     if (rounds == 0)
+	  rounds = 20;  /* default value */
+
+     n = tensor_sz(p->sz);
+     vecn = tensor_sz(p->vecsz);
+     N = n * vecn;
+
+     d = (dim_stuff *) bench_malloc(sizeof(dim_stuff) * p->sz->rnk);
+     for (i = 0; i < p->sz->rnk; ++i) {
+	  int n0, i0, k0;
+	  trigfun ti, ts;
+
+	  d[i].n = n0 = p->sz->dims[i].n;
+	  if (p->k[i] > R2R_DHT)
+	       n0 = 2 * (n0 + (p->k[i] == R2R_REDFT00 ? -1 : 
+			       (p->k[i] == R2R_RODFT00 ? 1 : 0)));
+	  
+	  switch (p->k[i]) {
+	      case R2R_R2HC:
+		   i0 = k0 = 0;
+		   ti = realhalf;
+		   ts = coshalf;
+		   break;
+	      case R2R_DHT:
+		   i0 = k0 = 0;
+		   ti = unity;
+		   ts = cos00;
+		   break;
+	      case R2R_HC2R:
+		   i0 = k0 = 0;
+		   ti = unity;
+		   ts = cos00;
+		   break;
+	      case R2R_REDFT00:
+		   i0 = k0 = 0;
+		   ti = ts = cos00;
+		   break;
+	      case R2R_REDFT01:
+		   i0 = k0 = 0;
+		   ti = ts = cos01;
+		   break;
+	      case R2R_REDFT10:
+		   i0 = k0 = 0;
+		   ti = cos10; impulse_amp *= 2.0;
+		   ts = cos00;
+		   break;
+	      case R2R_REDFT11:
+		   i0 = k0 = 0;
+		   ti = cos11; impulse_amp *= 2.0;
+		   ts = cos01;
+		   break;
+	      case R2R_RODFT00:
+		   i0 = k0 = 1;
+		   ti = sin00; impulse_amp *= 2.0;
+		   ts = cos00;
+		   break;
+	      case R2R_RODFT01:
+		   i0 = 1; k0 = 0;
+		   ti = sin01; impulse_amp *= n == 1 ? 1.0 : 2.0;
+		   ts = cos01;
+		   break;
+	      case R2R_RODFT10:
+		   i0 = 0; k0 = 1;
+		   ti = sin10; impulse_amp *= 2.0;
+		   ts = cos00;
+		   break;
+	      case R2R_RODFT11:
+		   i0 = k0 = 0;
+		   ti = sin11; impulse_amp *= 2.0;
+		   ts = cos01;
+		   break;
+	      default:
+		   BENCH_ASSERT(0);
+		   return;
+	  }
+
+	  d[i].n0 = n0;
+	  d[i].i0 = i0;
+	  d[i].k0 = k0;
+	  d[i].ti = ti;
+	  d[i].ts = ts;
+     }
+
+
+     inA = (R *) bench_malloc(N * sizeof(R));
+     inB = (R *) bench_malloc(N * sizeof(R));
+     inC = (R *) bench_malloc(N * sizeof(R));
+     outA = (R *) bench_malloc(N * sizeof(R));
+     outB = (R *) bench_malloc(N * sizeof(R));
+     outC = (R *) bench_malloc(N * sizeof(R));
+     tmp = (R *) bench_malloc(N * sizeof(R));
+
+     nfo.p = p;
+     nfo.probsz = p->sz;
+     nfo.totalsz = tensor_append(p->vecsz, nfo.probsz);
+     nfo.pckdsz = verify_pack(nfo.totalsz, 1);
+     nfo.pckdvecsz = verify_pack(p->vecsz, tensor_sz(nfo.probsz));
+
+     e->i = rimpulse(d, impulse_amp, n, vecn, &nfo,
+		     inA, inB, inC, outA, outB, outC, tmp, rounds, tol);
+     e->l = rlinear(N, &nfo, inA, inB, inC, outA, outB, outC, tmp, rounds,tol);
+     e->s = t_shift(n, vecn, &nfo, inA, inB, outA, outB, tmp, 
+		    rounds, tol, d);
+
+     /* grr, verify-lib.c:preserves_input() only works for complex */
+     if (!p->in_place && !p->destroy_input) {
+	  bench_tensor *totalsz_swap, *pckdsz_swap;
+	  totalsz_swap = tensor_copy_swapio(nfo.totalsz);
+	  pckdsz_swap = tensor_copy_swapio(nfo.pckdsz);
+
+	  for (i = 0; i < rounds; ++i) {
+	       rarand(inA, N);
+	       dofft(&nfo, inA, outB);
+	       cpyr((R *) nfo.p->in, totalsz_swap, inB, pckdsz_swap);
+	       racmp(inB, inA, N, "preserves_input", 0.0);
+	  }
+
+	  tensor_destroy(totalsz_swap);
+	  tensor_destroy(pckdsz_swap);
+     }
+
+     tensor_destroy(nfo.totalsz);
+     tensor_destroy(nfo.pckdsz);
+     tensor_destroy(nfo.pckdvecsz);
+     bench_free(tmp);
+     bench_free(outC);
+     bench_free(outB);
+     bench_free(outA);
+     bench_free(inC);
+     bench_free(inB);
+     bench_free(inA);
+     bench_free(d);
+}
+
+
+typedef struct {
+     dofft_closure k;
+     bench_problem *p;
+     int n0;
+} dofft_r2r_closure;
+
+static void cpyr1(int n, R *in, int is, R *out, int os, R scale)
+{
+     int i;
+     for (i = 0; i < n; ++i)
+	  out[i * os] = in[i * is] * scale;
+}
+
+static void mke00(C *a, int n, int c)
+{
+     int i;
+     for (i = 1; i + i < n; ++i)
+	  a[n - i][c] = a[i][c];
+}
+
+static void mkre00(C *a, int n)
+{
+     mkreal(a, n);
+     mke00(a, n, 0);
+}
+
+static void mkimag(C *a, int n)
+{
+     int i;
+     for (i = 0; i < n; ++i)
+	  c_re(a[i]) = 0.0;
+}
+
+static void mko00(C *a, int n, int c)
+{
+     int i;
+     a[0][c] = 0.0;
+     for (i = 1; i + i < n; ++i)
+	  a[n - i][c] = -a[i][c];
+     if (i + i == n)
+	  a[i][c] = 0.0;
+}
+
+static void mkro00(C *a, int n)
+{
+     mkreal(a, n);
+     mko00(a, n, 0);
+}
+
+static void mkio00(C *a, int n)
+{
+     mkimag(a, n);
+     mko00(a, n, 1);
+}
+
+static void mkre01(C *a, int n) /* n should be be multiple of 4 */
+{
+     R a0;
+     a0 = c_re(a[0]);
+     mko00(a, n/2, 0);
+     c_re(a[n/2]) = -(c_re(a[0]) = a0);
+     mkre00(a, n);
+}
+
+static void mkro01(C *a, int n) /* n should be be multiple of 4 */
+{
+     c_re(a[0]) = c_im(a[0]) = 0.0;
+     mkre00(a, n/2);
+     mkro00(a, n);
+}
+
+static void mkoddonly(C *a, int n)
+{
+     int i;
+     for (i = 0; i < n; i += 2)
+	  c_re(a[i]) = c_im(a[i]) = 0.0;
+}
+
+static void mkre10(C *a, int n)
+{
+     mkoddonly(a, n);
+     mkre00(a, n);
+}
+
+static void mkio10(C *a, int n)
+{
+     mkoddonly(a, n);
+     mkio00(a, n);
+}
+
+static void mkre11(C *a, int n)
+{
+     mkoddonly(a, n);
+     mko00(a, n/2, 0);
+     mkre00(a, n);
+}
+
+static void mkro11(C *a, int n)
+{
+     mkoddonly(a, n);
+     mkre00(a, n/2);
+     mkro00(a, n);
+}
+
+static void mkio11(C *a, int n)
+{
+     mkoddonly(a, n);
+     mke00(a, n/2, 1);
+     mkio00(a, n);
+}
+
+static void r2r_apply(dofft_closure *k_, bench_complex *in, bench_complex *out)
+{
+     dofft_r2r_closure *k = (dofft_r2r_closure *)k_;
+     bench_problem *p = k->p;
+     bench_real *ri, *ro;
+     int n, is, os;
+
+     n = p->sz->dims[0].n;
+     is = p->sz->dims[0].is;
+     os = p->sz->dims[0].os;
+
+     ri = (bench_real *) p->in;
+     ro = (bench_real *) p->out;
+
+     switch (p->k[0]) {
+	 case R2R_R2HC:
+	      cpyr1(n, &c_re(in[0]), 2, ri, is, 1.0);
+	      break;
+	 case R2R_HC2R:
+	      cpyr1(n/2 + 1, &c_re(in[0]), 2, ri, is, 1.0);
+	      cpyr1((n+1)/2 - 1, &c_im(in[n-1]), -2, ri + is*(n-1), -is, 1.0);
+	      break;
+	 case R2R_REDFT00:
+	      cpyr1(n, &c_re(in[0]), 2, ri, is, 1.0);
+	      break;
+	 case R2R_RODFT00:
+	      cpyr1(n, &c_re(in[1]), 2, ri, is, 1.0);
+	      break;
+	 case R2R_REDFT01:
+	      cpyr1(n, &c_re(in[0]), 2, ri, is, 1.0);
+	      break;
+	 case R2R_REDFT10:
+	      cpyr1(n, &c_re(in[1]), 4, ri, is, 1.0);
+	      break;
+	 case R2R_RODFT01:
+	      cpyr1(n, &c_re(in[1]), 2, ri, is, 1.0);
+	      break;
+	 case R2R_RODFT10:
+	      cpyr1(n, &c_im(in[1]), 4, ri, is, 1.0);
+	      break;
+	 case R2R_REDFT11:
+	      cpyr1(n, &c_re(in[1]), 4, ri, is, 1.0);
+	      break;
+	 case R2R_RODFT11:
+	      cpyr1(n, &c_re(in[1]), 4, ri, is, 1.0);
+	      break;
+	 default:
+	      BENCH_ASSERT(0); /* not yet implemented */
+     }
+
+     after_problem_rcopy_from(p, ri);
+     doit(1, p);
+     after_problem_rcopy_to(p, ro);
+
+     switch (p->k[0]) {
+	 case R2R_R2HC:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_re(in[0]), 2, 1.0);
+	      cpyr1(n/2 + 1, ro, os, &c_re(out[0]), 2, 1.0);
+	      cpyr1((n+1)/2 - 1, ro + os*(n-1), -os, &c_im(out[1]), 2, 1.0);
+	      c_im(out[0]) = 0.0;
+	      if (n % 2 == 0)
+		   c_im(out[n/2]) = 0.0;
+	      mkhermitian1(out, n);
+	      break;
+	 case R2R_HC2R:
+	      if (k->k.recopy_input) {
+		   cpyr1(n/2 + 1, ri, is, &c_re(in[0]), 2, 1.0);
+		   cpyr1((n+1)/2 - 1, ri + is*(n-1), -is, &c_im(in[1]), 2,1.0);
+	      }
+	      cpyr1(n, ro, os, &c_re(out[0]), 2, 1.0);
+	      mkreal(out, n);
+	      break;
+	 case R2R_REDFT00:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_re(in[0]), 2, 1.0);
+	      cpyr1(n, ro, os, &c_re(out[0]), 2, 1.0);
+	      mkre00(out, k->n0);
+	      break;
+	 case R2R_RODFT00:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_im(in[1]), 2, -1.0);
+	      cpyr1(n, ro, os, &c_im(out[1]), 2, -1.0);
+	      mkio00(out, k->n0);
+	      break;
+	 case R2R_REDFT01:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_re(in[0]), 2, 1.0);
+	      cpyr1(n, ro, os, &c_re(out[1]), 4, 2.0);
+	      mkre10(out, k->n0);
+	      break;
+	 case R2R_REDFT10:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_re(in[1]), 4, 2.0);
+	      cpyr1(n, ro, os, &c_re(out[0]), 2, 1.0);
+	      mkre01(out, k->n0);
+	      break;
+	 case R2R_RODFT01:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_re(in[1]), 2, 1.0);
+	      cpyr1(n, ro, os, &c_im(out[1]), 4, -2.0);
+	      mkio10(out, k->n0);
+	      break;
+	 case R2R_RODFT10:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_im(in[1]), 4, -2.0);
+	      cpyr1(n, ro, os, &c_re(out[1]), 2, 1.0);
+	      mkro01(out, k->n0);
+	      break;
+	 case R2R_REDFT11:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_re(in[1]), 4, 2.0);
+	      cpyr1(n, ro, os, &c_re(out[1]), 4, 2.0);
+	      mkre11(out, k->n0);
+	      break;
+	 case R2R_RODFT11:
+	      if (k->k.recopy_input)
+		   cpyr1(n, ri, is, &c_im(in[1]), 4, -2.0);
+	      cpyr1(n, ro, os, &c_im(out[1]), 4, -2.0);
+	      mkio11(out, k->n0);
+	      break;
+	 default:
+	      BENCH_ASSERT(0); /* not yet implemented */
+     }
+}
+
+void accuracy_r2r(bench_problem *p, int rounds, int impulse_rounds,
+		  double t[6])
+{
+     dofft_r2r_closure k;
+     int n, n0 = 1;
+     C *a, *b;
+     aconstrain constrain = 0;
+
+     BENCH_ASSERT(p->kind == PROBLEM_R2R);
+     BENCH_ASSERT(p->sz->rnk == 1);
+     BENCH_ASSERT(p->vecsz->rnk == 0);
+
+     k.k.apply = r2r_apply;
+     k.k.recopy_input = 0;
+     k.p = p;
+     n = tensor_sz(p->sz);
+     
+     switch (p->k[0]) {
+         case R2R_R2HC: constrain = mkreal; n0 = n; break;
+         case R2R_HC2R: constrain = mkhermitian1; n0 = n; break;
+         case R2R_REDFT00: constrain = mkre00; n0 = 2*(n-1); break;
+         case R2R_RODFT00: constrain = mkro00; n0 = 2*(n+1); break;
+         case R2R_REDFT01: constrain = mkre01; n0 = 4*n; break;
+         case R2R_REDFT10: constrain = mkre10; n0 = 4*n; break;
+         case R2R_RODFT01: constrain = mkro01; n0 = 4*n; break;
+         case R2R_RODFT10: constrain = mkio10; n0 = 4*n; break;
+         case R2R_REDFT11: constrain = mkre11; n0 = 8*n; break;
+         case R2R_RODFT11: constrain = mkro11; n0 = 8*n; break;
+	 default: BENCH_ASSERT(0); /* not yet implemented */
+     }
+     k.n0 = n0;
+
+     a = (C *) bench_malloc(n0 * sizeof(C));
+     b = (C *) bench_malloc(n0 * sizeof(C));
+     accuracy_test(&k.k, constrain, -1, n0, a, b, rounds, impulse_rounds, t);
+     bench_free(b);
+     bench_free(a);
+}