Chris@10: /*
Chris@10:  * Copyright (c) 2003, 2007-11 Matteo Frigo
Chris@10:  * Copyright (c) 2003, 2007-11 Massachusetts Institute of Technology
Chris@10:  *
Chris@10:  * This program is free software; you can redistribute it and/or modify
Chris@10:  * it under the terms of the GNU General Public License as published by
Chris@10:  * the Free Software Foundation; either version 2 of the License, or
Chris@10:  * (at your option) any later version.
Chris@10:  *
Chris@10:  * This program is distributed in the hope that it will be useful,
Chris@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@10:  * GNU General Public License for more details.
Chris@10:  *
Chris@10:  * You should have received a copy of the GNU General Public License
Chris@10:  * along with this program; if not, write to the Free Software
Chris@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
Chris@10:  *
Chris@10:  */
Chris@10: 
Chris@10: 
Chris@10: #include "rdft.h"
Chris@10: 
Chris@10: /* Check if the vecsz/sz strides are consistent with the problem
Chris@10:    being in-place for vecsz.dim[vdim], or for all dimensions
Chris@10:    if vdim == RNK_MINFTY.  We can't just use tensor_inplace_strides
Chris@10:    because rdft transforms have the unfortunate property of
Chris@10:    differing input and output sizes.   This routine is not
Chris@10:    exhaustive; we only return 1 for the most common case.  */
Chris@10: int X(rdft2_inplace_strides)(const problem_rdft2 *p, int vdim)
Chris@10: {
Chris@10:      INT N, Nc;
Chris@10:      INT rs, cs;
Chris@10:      int i;
Chris@10:      
Chris@10:      for (i = 0; i + 1 < p->sz->rnk; ++i)
Chris@10: 	  if (p->sz->dims[i].is != p->sz->dims[i].os)
Chris@10: 	       return 0;
Chris@10: 
Chris@10:      if (!FINITE_RNK(p->vecsz->rnk) || p->vecsz->rnk == 0)
Chris@10: 	  return 1;
Chris@10:      if (!FINITE_RNK(vdim)) { /* check all vector dimensions */
Chris@10: 	  for (vdim = 0; vdim < p->vecsz->rnk; ++vdim)
Chris@10: 	       if (!X(rdft2_inplace_strides)(p, vdim))
Chris@10: 		    return 0;
Chris@10: 	  return 1;
Chris@10:      }
Chris@10: 
Chris@10:      A(vdim < p->vecsz->rnk);
Chris@10:      if (p->sz->rnk == 0)
Chris@10: 	  return(p->vecsz->dims[vdim].is == p->vecsz->dims[vdim].os);
Chris@10: 
Chris@10:      N = X(tensor_sz)(p->sz);
Chris@10:      Nc = (N / p->sz->dims[p->sz->rnk-1].n) *
Chris@10: 	  (p->sz->dims[p->sz->rnk-1].n/2 + 1);
Chris@10:      X(rdft2_strides)(p->kind, p->sz->dims + p->sz->rnk - 1, &rs, &cs);
Chris@10: 
Chris@10:      /* the factor of 2 comes from the fact that RS is the stride
Chris@10: 	of p->r0 and p->r1, which is twice as large as the strides
Chris@10: 	in the r2r case */
Chris@10:      return(p->vecsz->dims[vdim].is == p->vecsz->dims[vdim].os
Chris@10: 	    && (X(iabs)(2 * p->vecsz->dims[vdim].os)
Chris@10: 		>= X(imax)(2 * Nc * X(iabs)(cs), N * X(iabs)(rs))));
Chris@10: }