/* Implementation of the TRANSPOSE intrinsic
   Copyright (C) 2003-2016 Free Software Foundation, Inc.
   Contributed by Tobias Schlüter

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

Libgfortran 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 3 of the License, or (at your option) any later version.

Libgfortran 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.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */

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

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

static void
transpose_internal (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(ret);

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

      GFC_DIMENSION_SET(ret->dim[0], 0, GFC_DESCRIPTOR_EXTENT(source,1) - 1,
			1);

      GFC_DIMENSION_SET(ret->dim[1], 0, GFC_DESCRIPTOR_EXTENT(source,0) - 1,
			GFC_DESCRIPTOR_EXTENT(source, 1));

      ret->base_addr = xmallocarray (size0 ((array_t*)ret), size);
      ret->offset = 0;
    }
  else if (unlikely (compile_options.bounds_check))
    {
      index_type ret_extent, src_extent;

      ret_extent = GFC_DESCRIPTOR_EXTENT(ret,0);
      src_extent = GFC_DESCRIPTOR_EXTENT(source,1);

      if (src_extent != ret_extent)
	runtime_error ("Incorrect extent in return value of TRANSPOSE"
		       " intrinsic in dimension 1: is %ld,"
		       " should be %ld", (long int) src_extent,
		       (long int) ret_extent);

      ret_extent = GFC_DESCRIPTOR_EXTENT(ret,1);
      src_extent = GFC_DESCRIPTOR_EXTENT(source,0);

      if (src_extent != ret_extent)
	runtime_error ("Incorrect extent in return value of TRANSPOSE"
		       " intrinsic in dimension 2: is %ld,"
		       " should be %ld", (long int) src_extent,
		       (long int) ret_extent);

    }

  sxstride = GFC_DESCRIPTOR_STRIDE_BYTES(source,0);
  systride = GFC_DESCRIPTOR_STRIDE_BYTES(source,1);
  xcount = GFC_DESCRIPTOR_EXTENT(source,0);
  ycount = GFC_DESCRIPTOR_EXTENT(source,1);

  rxstride = GFC_DESCRIPTOR_STRIDE_BYTES(ret,0);
  rystride = GFC_DESCRIPTOR_STRIDE_BYTES(ret,1);

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

  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);
    }
}


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

void
transpose (gfc_array_char *ret, gfc_array_char *source)
{
  transpose_internal (ret, source);
}


extern void transpose_char (gfc_array_char *, GFC_INTEGER_4,
			    gfc_array_char *, GFC_INTEGER_4);
export_proto(transpose_char);

void
transpose_char (gfc_array_char *ret,
		GFC_INTEGER_4 ret_length __attribute__((unused)),
		gfc_array_char *source,
		GFC_INTEGER_4 source_length __attribute__((unused)))
{
  transpose_internal (ret, source);
}


extern void transpose_char4 (gfc_array_char *, GFC_INTEGER_4,
			     gfc_array_char *, GFC_INTEGER_4);
export_proto(transpose_char4);

void
transpose_char4 (gfc_array_char *ret,
		 GFC_INTEGER_4 ret_length __attribute__((unused)),
		 gfc_array_char *source,
		 GFC_INTEGER_4 source_length __attribute__((unused)))
{
  transpose_internal (ret, source);
}