blob: c92b682643815969e1867b06f216a79763d9b71f [file] [log] [blame]
/* Implementation of the NORM2 intrinsic
Copyright (C) 2010-2019 Free Software Foundation, Inc.
Contributed by Tobias Burnus <burnus@net-b.de>
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"
#if defined (HAVE_GFC_REAL_8) && defined (HAVE_GFC_REAL_8) && defined (HAVE_SQRT) && defined (HAVE_FABS)
#define MATHFUNC(funcname) funcname
extern void norm2_r8 (gfc_array_r8 * const restrict,
gfc_array_r8 * const restrict, const index_type * const restrict);
export_proto(norm2_r8);
void
norm2_r8 (gfc_array_r8 * const restrict retarray,
gfc_array_r8 * const restrict array,
const index_type * const restrict pdim)
{
index_type count[GFC_MAX_DIMENSIONS];
index_type extent[GFC_MAX_DIMENSIONS];
index_type sstride[GFC_MAX_DIMENSIONS];
index_type dstride[GFC_MAX_DIMENSIONS];
const GFC_REAL_8 * restrict base;
GFC_REAL_8 * restrict dest;
index_type rank;
index_type n;
index_type len;
index_type delta;
index_type dim;
int continue_loop;
/* Make dim zero based to avoid confusion. */
rank = GFC_DESCRIPTOR_RANK (array) - 1;
dim = (*pdim) - 1;
if (unlikely (dim < 0 || dim > rank))
{
runtime_error ("Dim argument incorrect in NORM intrinsic: "
"is %ld, should be between 1 and %ld",
(long int) dim + 1, (long int) rank + 1);
}
len = GFC_DESCRIPTOR_EXTENT(array,dim);
if (len < 0)
len = 0;
delta = GFC_DESCRIPTOR_STRIDE(array,dim);
for (n = 0; n < dim; n++)
{
sstride[n] = GFC_DESCRIPTOR_STRIDE(array,n);
extent[n] = GFC_DESCRIPTOR_EXTENT(array,n);
if (extent[n] < 0)
extent[n] = 0;
}
for (n = dim; n < rank; n++)
{
sstride[n] = GFC_DESCRIPTOR_STRIDE(array, n + 1);
extent[n] = GFC_DESCRIPTOR_EXTENT(array, n + 1);
if (extent[n] < 0)
extent[n] = 0;
}
if (retarray->base_addr == NULL)
{
size_t alloc_size, str;
for (n = 0; n < rank; n++)
{
if (n == 0)
str = 1;
else
str = GFC_DESCRIPTOR_STRIDE(retarray,n-1) * extent[n-1];
GFC_DIMENSION_SET(retarray->dim[n], 0, extent[n] - 1, str);
}
retarray->offset = 0;
retarray->dtype.rank = rank;
alloc_size = GFC_DESCRIPTOR_STRIDE(retarray,rank-1) * extent[rank-1];
retarray->base_addr = xmallocarray (alloc_size, sizeof (GFC_REAL_8));
if (alloc_size == 0)
{
/* Make sure we have a zero-sized array. */
GFC_DIMENSION_SET(retarray->dim[0], 0, -1, 1);
return;
}
}
else
{
if (rank != GFC_DESCRIPTOR_RANK (retarray))
runtime_error ("rank of return array incorrect in"
" NORM intrinsic: is %ld, should be %ld",
(long int) (GFC_DESCRIPTOR_RANK (retarray)),
(long int) rank);
if (unlikely (compile_options.bounds_check))
bounds_ifunction_return ((array_t *) retarray, extent,
"return value", "NORM");
}
for (n = 0; n < rank; n++)
{
count[n] = 0;
dstride[n] = GFC_DESCRIPTOR_STRIDE(retarray,n);
if (extent[n] <= 0)
return;
}
base = array->base_addr;
dest = retarray->base_addr;
continue_loop = 1;
while (continue_loop)
{
const GFC_REAL_8 * restrict src;
GFC_REAL_8 result;
src = base;
{
GFC_REAL_8 scale;
result = 0;
scale = 1;
if (len <= 0)
*dest = 0;
else
{
#if ! defined HAVE_BACK_ARG
for (n = 0; n < len; n++, src += delta)
{
#endif
if (*src != 0)
{
GFC_REAL_8 absX, val;
absX = MATHFUNC(fabs) (*src);
if (scale < absX)
{
val = scale / absX;
result = 1 + result * val * val;
scale = absX;
}
else
{
val = absX / scale;
result += val * val;
}
}
}
result = scale * MATHFUNC(sqrt) (result);
*dest = result;
}
}
/* Advance to the next element. */
count[0]++;
base += sstride[0];
dest += dstride[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 probably not worth it. */
base -= sstride[n] * extent[n];
dest -= dstride[n] * extent[n];
n++;
if (n >= rank)
{
/* Break out of the loop. */
continue_loop = 0;
break;
}
else
{
count[n]++;
base += sstride[n];
dest += dstride[n];
}
}
}
}
#endif