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/* $Id: $ */
/* Copyright (C) 1997 Sverre Hvammen Johansen,
* Department of Informatics, University of Oslo.
*
* This program 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; version 2.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "cim.h"
#include "config.h"
/******************************************************************************
REAL PROCEDURE POWRI(r,i) */
double
__rpowri (r, i)
double r;
long i;
{
long k = 1,
s;
double result;
if (i == 0 & r == 0.0)
__rerror ("Power: Illegal parameters");
if (i < 0)
{
i = -i;
s = 1;
}
else
s = 0;
if (i == 0)
return (1.0);
while (__TRUE)
{
if (k & i)
{
result = r;
if ((i ^= k) == 0)
return (s == 1 ? 1.0 / result : result);
k <<= 1;
r *= r;
break;
}
k <<= 1;
r *= r;
}
while (__TRUE)
{
if (k & i)
{
result *= r;
if ((i ^= k) == 0)
return (s == 1 ? 1.0 / result : result);
}
k <<= 1;
r *= r;
}
}
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