adea5e16e4
2007-03-14 Thomas Koenig <Thomas.Koenig@online.de> PR libfortran/30690 * all.m4: Quote everything, except for m4 macros. * any.m4: Likewise. * count.m4: Likewise. * cshift1.m4: Likewise. * eoshift1.m4: Likewise. * eoshift3.m4: Likewise. * exponent.m4: Likewise. * fraction.m4: Likewise. * in_pack.m4: Likewise. * in_unpack.m4: Likewise. * matmul.m4: Likewise. * matmull.m4: Likewise. * nearest.m4: Likewise. * pow.m4: Likewise. * product.m4: Likewise. * reshape.m4: Likewise. * rrspacing.m4: Likewise. * set_exponent.m4: Likewise. * shape.m4: Likewise. * spacing.m4: Likewise. * transpose.m4: Likewise. From-SVN: r122927
89 lines
2.4 KiB
Plaintext
89 lines
2.4 KiB
Plaintext
`/* Support routines for the intrinsic power (**) operator.
|
|
Copyright 2004 Free Software Foundation, Inc.
|
|
Contributed by Paul Brook
|
|
|
|
This file is part of the GNU Fortran 95 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 2 of the License, or (at your option) any later version.
|
|
|
|
In addition to the permissions in the GNU General Public License, the
|
|
Free Software Foundation gives you unlimited permission to link the
|
|
compiled version of this file into combinations with other programs,
|
|
and to distribute those combinations without any restriction coming
|
|
from the use of this file. (The General Public License restrictions
|
|
do apply in other respects; for example, they cover modification of
|
|
the file, and distribution when not linked into a combine
|
|
executable.)
|
|
|
|
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.
|
|
|
|
You should have received a copy of the GNU General Public
|
|
License along with libgfortran; see the file COPYING. If not,
|
|
write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
|
|
Boston, MA 02110-1301, USA. */
|
|
|
|
#include "config.h"
|
|
#include "libgfortran.h"'
|
|
include(iparm.m4)dnl
|
|
|
|
/* Use Binary Method to calculate the powi. This is not an optimal but
|
|
a simple and reasonable arithmetic. See section 4.6.3, "Evaluation of
|
|
Powers" of Donald E. Knuth, "Seminumerical Algorithms", Vol. 2, "The Art
|
|
of Computer Programming", 3rd Edition, 1998. */
|
|
|
|
`#if defined (HAVE_'rtype_name`) && defined (HAVE_'atype_name`)'
|
|
|
|
rtype_name `pow_'rtype_code`_'atype_code` ('rtype_name` a, 'atype_name` b);
|
|
export_proto(pow_'rtype_code`_'atype_code`);
|
|
|
|
'rtype_name`
|
|
pow_'rtype_code`_'atype_code` ('rtype_name` a, 'atype_name` b)
|
|
{
|
|
'rtype_name` pow, x;
|
|
'atype_name` n;
|
|
GFC_UINTEGER_'atype_kind` u;
|
|
|
|
n = b;
|
|
x = a;
|
|
pow = 1;
|
|
if (n != 0)
|
|
{
|
|
if (n < 0)
|
|
{
|
|
'ifelse(rtype_letter,i,`dnl
|
|
if (x == 1)
|
|
return 1;
|
|
if (x == -1)
|
|
return (n & 1) ? -1 : 1;
|
|
return (x == 0) ? 1 / x : 0;
|
|
',`
|
|
u = -n;
|
|
x = pow / x;
|
|
')dnl
|
|
` }
|
|
else
|
|
{
|
|
u = n;
|
|
}
|
|
for (;;)
|
|
{
|
|
if (u & 1)
|
|
pow *= x;
|
|
u >>= 1;
|
|
if (u)
|
|
x *= x;
|
|
else
|
|
break;
|
|
}
|
|
}
|
|
return pow;
|
|
}
|
|
|
|
#endif'
|