cannam@127: /*
cannam@127:  * Copyright (c) 2003, 2007-14 Matteo Frigo
cannam@127:  * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
cannam@127:  *
cannam@127:  * This program is free software; you can redistribute it and/or modify
cannam@127:  * it under the terms of the GNU General Public License as published by
cannam@127:  * the Free Software Foundation; either version 2 of the License, or
cannam@127:  * (at your option) any later version.
cannam@127:  *
cannam@127:  * This program is distributed in the hope that it will be useful,
cannam@127:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
cannam@127:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
cannam@127:  * GNU General Public License for more details.
cannam@127:  *
cannam@127:  * You should have received a copy of the GNU General Public License
cannam@127:  * along with this program; if not, write to the Free Software
cannam@127:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
cannam@127:  *
cannam@127:  */
cannam@127: 
cannam@127: 
cannam@127: #include "rdft.h"
cannam@127: 
cannam@127: /* Check if the vecsz/sz strides are consistent with the problem
cannam@127:    being in-place for vecsz.dim[vdim], or for all dimensions
cannam@127:    if vdim == RNK_MINFTY.  We can't just use tensor_inplace_strides
cannam@127:    because rdft transforms have the unfortunate property of
cannam@127:    differing input and output sizes.   This routine is not
cannam@127:    exhaustive; we only return 1 for the most common case.  */
cannam@127: int X(rdft2_inplace_strides)(const problem_rdft2 *p, int vdim)
cannam@127: {
cannam@127:      INT N, Nc;
cannam@127:      INT rs, cs;
cannam@127:      int i;
cannam@127:      
cannam@127:      for (i = 0; i + 1 < p->sz->rnk; ++i)
cannam@127: 	  if (p->sz->dims[i].is != p->sz->dims[i].os)
cannam@127: 	       return 0;
cannam@127: 
cannam@127:      if (!FINITE_RNK(p->vecsz->rnk) || p->vecsz->rnk == 0)
cannam@127: 	  return 1;
cannam@127:      if (!FINITE_RNK(vdim)) { /* check all vector dimensions */
cannam@127: 	  for (vdim = 0; vdim < p->vecsz->rnk; ++vdim)
cannam@127: 	       if (!X(rdft2_inplace_strides)(p, vdim))
cannam@127: 		    return 0;
cannam@127: 	  return 1;
cannam@127:      }
cannam@127: 
cannam@127:      A(vdim < p->vecsz->rnk);
cannam@127:      if (p->sz->rnk == 0)
cannam@127: 	  return(p->vecsz->dims[vdim].is == p->vecsz->dims[vdim].os);
cannam@127: 
cannam@127:      N = X(tensor_sz)(p->sz);
cannam@127:      Nc = (N / p->sz->dims[p->sz->rnk-1].n) *
cannam@127: 	  (p->sz->dims[p->sz->rnk-1].n/2 + 1);
cannam@127:      X(rdft2_strides)(p->kind, p->sz->dims + p->sz->rnk - 1, &rs, &cs);
cannam@127: 
cannam@127:      /* the factor of 2 comes from the fact that RS is the stride
cannam@127: 	of p->r0 and p->r1, which is twice as large as the strides
cannam@127: 	in the r2r case */
cannam@127:      return(p->vecsz->dims[vdim].is == p->vecsz->dims[vdim].os
cannam@127: 	    && (X(iabs)(2 * p->vecsz->dims[vdim].os)
cannam@127: 		>= X(imax)(2 * Nc * X(iabs)(cs), N * X(iabs)(rs))));
cannam@127: }