gcc/libgfortran/intrinsics/transpose_generic.c

/* Implementation of the TRANSPOSE intrinsic
   Copyright 2003 Free Software Foundation, Inc.
   Contributed by Tobias Schl<EFBFBD>ter

This file is part of the GNU Fortran 95 runtime library (libgfor).

Libgfor is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

Ligbfor 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with libgfor; see the file COPYING.LIB.  If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "libgfortran.h"

extern void transpose (gfc_array_char *, gfc_array_char *);
export_proto(transpose);

void
transpose (gfc_array_char *ret, gfc_array_char *source)
{
  /* r.* indicates the return array.  */
  index_type rxstride, rystride;
  char *rptr;
  /* s.* indicates the source array.  */
  index_type sxstride, systride;
  const char *sptr;

  index_type xcount, ycount;
  index_type x, y;
  index_type size;

  assert (GFC_DESCRIPTOR_RANK (source) == 2
          && GFC_DESCRIPTOR_RANK (ret) == 2);

  size = GFC_DESCRIPTOR_SIZE (source);

  if (ret->data == NULL)
    {
      assert (ret->dtype == source->dtype);

      ret->dim[0].lbound = 0;
      ret->dim[0].ubound = source->dim[1].ubound - source->dim[1].lbound;
      ret->dim[0].stride = 1;

      ret->dim[1].lbound = 0;
      ret->dim[1].ubound = source->dim[0].ubound - source->dim[0].lbound;
      ret->dim[1].stride = ret->dim[0].ubound+1;

      ret->data = internal_malloc_size (size * size0 ((array_t*)ret));
      ret->base = 0;
    }

  sxstride = source->dim[0].stride * size;
  if (sxstride == 0)
    sxstride = size;
  systride = source->dim[1].stride * size;
  xcount = source->dim[0].ubound + 1 - source->dim[0].lbound;
  ycount = source->dim[1].ubound + 1 - source->dim[1].lbound;

  rxstride = ret->dim[0].stride * size;
  if (rxstride == 0)
    rxstride = size;
  rystride = ret->dim[1].stride * size;

  rptr = ret->data;
  sptr = source->data;

  for (y = 0; y < ycount; y++)
    {
      for (x = 0; x < xcount; x++)
        {
          memcpy (rptr, sptr, size);

          sptr += sxstride;
          rptr += rystride;
        }
      sptr += systride - (sxstride * xcount);
      rptr += rxstride - (rystride * xcount);
    }
}