gcc/libgfortran/intrinsics/reshape_generic.c
2004-05-13 02:41:07 -04:00

232 lines
6.5 KiB
C

/* Generic implementation of the RESHAPE intrinsic
Copyright 2002 Free Software Foundation, Inc.
Contributed by Paul Brook <paul@nowt.org>
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"
typedef GFC_ARRAY_DESCRIPTOR(1, index_type) shape_type;
typedef GFC_ARRAY_DESCRIPTOR(GFC_MAX_DIMENSIONS, char) parray;
/* The shape parameter is ignored. We can currently deduce the shape from the
return array. */
void
__reshape (parray * ret, parray * source, shape_type * shape,
parray * pad, shape_type * order)
{
/* r.* indicates the return array. */
index_type rcount[GFC_MAX_DIMENSIONS - 1];
index_type rextent[GFC_MAX_DIMENSIONS - 1];
index_type rstride[GFC_MAX_DIMENSIONS - 1];
index_type rstride0;
index_type rdim;
index_type rsize;
char *rptr;
/* s.* indicates the source array. */
index_type scount[GFC_MAX_DIMENSIONS - 1];
index_type sextent[GFC_MAX_DIMENSIONS - 1];
index_type sstride[GFC_MAX_DIMENSIONS - 1];
index_type sstride0;
index_type sdim;
index_type ssize;
const char *sptr;
/* p.* indicates the pad array. */
index_type pcount[GFC_MAX_DIMENSIONS - 1];
index_type pextent[GFC_MAX_DIMENSIONS - 1];
index_type pstride[GFC_MAX_DIMENSIONS - 1];
index_type pdim;
index_type psize;
const char *pptr;
const char *src;
int n;
int dim;
int size;
size = GFC_DESCRIPTOR_SIZE (ret);
if (ret->dim[0].stride == 0)
ret->dim[0].stride = 1;
if (source->dim[0].stride == 0)
source->dim[0].stride = 1;
if (shape->dim[0].stride == 0)
shape->dim[0].stride = 1;
if (pad && pad->dim[0].stride == 0)
pad->dim[0].stride = 1;
if (order && order->dim[0].stride == 0)
order->dim[0].stride = 1;
rdim = GFC_DESCRIPTOR_RANK (ret);
rsize = 1;
for (n = 0; n < rdim; n++)
{
if (order)
dim = order->data[n * order->dim[0].stride] - 1;
else
dim = n;
rcount[n] = 0;
rstride[n] = ret->dim[dim].stride;
rextent[n] = ret->dim[dim].ubound + 1 - ret->dim[dim].lbound;
if (rextent[n] != shape->data[dim * shape->dim[0].stride])
runtime_error ("shape and target do not conform");
if (rsize == rstride[n])
rsize *= rextent[n];
else
rsize = 0;
if (rextent[dim] <= 0)
return;
}
sdim = GFC_DESCRIPTOR_RANK (source);
ssize = 1;
for (n = 0; n < sdim; n++)
{
scount[n] = 0;
sstride[n] = source->dim[n].stride;
sextent[n] = source->dim[n].ubound + 1 - source->dim[n].lbound;
if (sextent[n] <= 0)
abort ();
if (rsize == sstride[n])
ssize *= sextent[n];
else
ssize = 0;
}
if (pad)
{
if (pad->dim[0].stride == 0)
pad->dim[0].stride = 1;
pdim = GFC_DESCRIPTOR_RANK (pad);
psize = 1;
for (n = 0; n < pdim; n++)
{
pcount[n] = 0;
pstride[n] = pad->dim[n].stride;
pextent[n] = pad->dim[n].ubound + 1 - pad->dim[n].lbound;
if (pextent[n] <= 0)
abort ();
if (psize == pstride[n])
psize *= pextent[n];
else
rsize = 0;
}
pptr = pad->data;
}
else
{
pdim = 0;
psize = 1;
pptr = NULL;
}
if (rsize != 0 && ssize != 0 && psize != 0)
{
rsize *= size;
ssize *= size;
psize *= size;
reshape_packed (ret->data, rsize, source->data, ssize,
pad ? pad->data : NULL, psize);
return;
}
rptr = ret->data;
src = sptr = source->data;
rstride0 = rstride[0] * size;
sstride0 = sstride[0] * size;
while (rptr)
{
/* Select between the source and pad arrays. */
memcpy(rptr, src, size);
/* Advance to the next element. */
rptr += rstride0;
src += sstride0;
rcount[0]++;
scount[0]++;
/* Advance to the next destination element. */
n = 0;
while (rcount[n] == rextent[n])
{
/* When we get to the end of a dimension, reset it and increment
the next dimension. */
rcount[n] = 0;
/* We could precalculate these products, but this is a less
frequently used path so proabably not worth it. */
rptr -= rstride[n] * rextent[n] * size;
n++;
if (n == rdim)
{
/* Break out of the loop. */
rptr = NULL;
break;
}
else
{
rcount[n]++;
rptr += rstride[n] * size;
}
}
/* Advance to the next source element. */
n = 0;
while (scount[n] == sextent[n])
{
/* When we get to the end of a dimension, reset it and increment
the next dimension. */
scount[n] = 0;
/* We could precalculate these products, but this is a less
frequently used path so proabably not worth it. */
src -= sstride[n] * sextent[n] * size;
n++;
if (n == sdim)
{
if (sptr && pad)
{
/* Switch to the pad array. */
sptr = NULL;
sdim = pdim;
for (dim = 0; dim < pdim; dim++)
{
scount[dim] = pcount[dim];
sextent[dim] = pextent[dim];
sstride[dim] = pstride[dim];
sstride0 = sstride[0] * size;
}
}
/* We now start again from the beginning of the pad array. */
src = pptr;
break;
}
else
{
scount[n]++;
sptr += sstride[n] * size;
}
}
}
}