gcc/libgfortran/intrinsics/eoshift2.c

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/* 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 <assert.h>
#include <string.h>
#include "libgfortran.h"
static const char zeros[16] =
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
/* TODO: make this work for large shifts when
sizeof(int) < sizeof (index_type). */
static void
__eoshift2 (const gfc_array_char * ret, const gfc_array_char * array,
int shift, const gfc_array_char * bound, int which)
{
/* r.* indicates the return array. */
index_type rstride[GFC_MAX_DIMENSIONS - 1];
index_type rstride0;
index_type roffset;
char *rptr;
char *dest;
/* s.* indicates the source array. */
index_type sstride[GFC_MAX_DIMENSIONS - 1];
index_type sstride0;
index_type soffset;
const char *sptr;
const char *src;
/* b.* indicates the bound array. */
index_type bstride[GFC_MAX_DIMENSIONS - 1];
index_type bstride0;
const char *bptr;
index_type count[GFC_MAX_DIMENSIONS - 1];
index_type extent[GFC_MAX_DIMENSIONS - 1];
index_type dim;
index_type size;
index_type len;
index_type n;
size = GFC_DESCRIPTOR_SIZE (ret);
which = which - 1;
extent[0] = 1;
count[0] = 0;
size = GFC_DESCRIPTOR_SIZE (array);
n = 0;
for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++)
{
if (dim == which)
{
roffset = ret->dim[dim].stride * size;
if (roffset == 0)
roffset = size;
soffset = array->dim[dim].stride * size;
if (soffset == 0)
soffset = size;
len = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
}
else
{
count[n] = 0;
extent[n] = array->dim[dim].ubound + 1 - array->dim[dim].lbound;
rstride[n] = ret->dim[dim].stride * size;
sstride[n] = array->dim[dim].stride * size;
if (bound)
bstride[n] = bound->dim[n].stride * size;
else
bstride[n] = 0;
n++;
}
}
if (sstride[0] == 0)
sstride[0] = size;
if (rstride[0] == 0)
rstride[0] = size;
if (bound && bstride[0] == 0)
bstride[0] = size;
dim = GFC_DESCRIPTOR_RANK (array);
rstride0 = rstride[0];
sstride0 = sstride[0];
bstride0 = bstride[0];
rptr = ret->data;
sptr = array->data;
if (bound)
bptr = bound->data;
else
bptr = zeros;
if (shift > 0)
len = len - shift;
else
len = len + shift;
while (rptr)
{
/* Do the shift for this dimension. */
if (shift > 0)
{
src = &sptr[shift * soffset];
dest = rptr;
}
else
{
src = sptr;
dest = &rptr[-shift * roffset];
}
for (n = 0; n < len; n++)
{
memcpy (dest, src, size);
dest += roffset;
src += soffset;
}
if (shift >= 0)
{
n = shift;
}
else
{
dest = rptr;
n = -shift;
}
while (n--)
{
memcpy (dest, bptr, size);
dest += roffset;
}
/* Advance to the next section. */
rptr += rstride0;
sptr += sstride0;
bptr += bstride0;
count[0]++;
n = 0;
while (count[n] == extent[n])
{
/* When we get to the end of a dimension, reset it and increment
the next dimension. */
count[n] = 0;
/* We could precalculate these products, but this is a less
frequently used path so proabably not worth it. */
rptr -= rstride[n] * extent[n];
sptr -= sstride[n] * extent[n];
bptr -= bstride[n] * extent[n];
n++;
if (n >= dim - 1)
{
/* Break out of the loop. */
rptr = NULL;
break;
}
else
{
count[n]++;
rptr += rstride[n];
sptr += sstride[n];
bptr += bstride[n];
}
}
}
}
void
__eoshift2_4 (const gfc_array_char * ret, const gfc_array_char * array,
const GFC_INTEGER_4 * pshift, const gfc_array_char * bound,
const GFC_INTEGER_4 * pdim)
{
__eoshift2 (ret, array, *pshift, bound, pdim ? *pdim : 1);
}
void
__eoshift2_8 (const gfc_array_char * ret, const gfc_array_char * array,
const GFC_INTEGER_8 * pshift, const gfc_array_char * bound,
const GFC_INTEGER_8 * pdim)
{
__eoshift2 (ret, array, *pshift, bound, pdim ? *pdim : 1);
}