1 files changed, 61 insertions, 0 deletions
diff --git a/src/fftw3/rdft/rdft2-inplace-strides.c b/src/fftw3/rdft/rdft2-inplace-strides.c
new file mode 100644
index 0000000..2171672
--- /dev/null
+++ b/src/fftw3/rdft/rdft2-inplace-strides.c
@@ -0,0 +1,61 @@
+/*
+ * 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
+ *
+ */
+
+/* $Id: rdft2-inplace-strides.c,v 1.1 2008/10/17 06:11:29 scuri Exp $ */
+
+#include "rdft.h"
+
+/* Check if the vecsz/sz strides are consistent with the problem
+   being in-place for vecsz.dim[vdim], or for all dimensions
+   if vdim == RNK_MINFTY.  We can't just use tensor_inplace_strides
+   because rdft transforms have the unfortunate property of
+   differing input and output sizes.   This routine is not
+   exhaustive; we only return 1 for the most common case.  */
+int X(rdft2_inplace_strides)(const problem_rdft2 *p, int vdim)
+{
+     int N, Nc;
+     int is, os;
+     int i;
+     
+     for (i = 0; i + 1 < p->sz->rnk; ++i)
+	  if (p->sz->dims[i].is != p->sz->dims[i].os)
+	       return 0;
+
+     if (!FINITE_RNK(p->vecsz->rnk) || p->vecsz->rnk == 0)
+	  return 1;
+     if (!FINITE_RNK(vdim)) { /* check all vector dimensions */
+	  for (vdim = 0; vdim < p->vecsz->rnk; ++vdim)
+	       if (!X(rdft2_inplace_strides)(p, vdim))
+		    return 0;
+	  return 1;
+     }
+
+     A(vdim < p->vecsz->rnk);
+     if (p->sz->rnk == 0)
+	  return(p->vecsz->dims[vdim].is == p->vecsz->dims[vdim].os);
+
+     N = X(tensor_sz)(p->sz);
+     Nc = (N / p->sz->dims[p->sz->rnk-1].n) *
+	  (p->sz->dims[p->sz->rnk-1].n/2 + 1);
+     X(rdft2_strides)(p->kind, p->sz->dims + p->sz->rnk - 1, &is, &os);
+     return(p->vecsz->dims[vdim].is == p->vecsz->dims[vdim].os
+	    && X(iabs)(p->vecsz->dims[vdim].os)
+	    >= X(imax)(Nc * X(iabs)(os), N * X(iabs)(is)));
+}