pow_ii.c

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/*

  Copyright (C) 2000, 2001 Silicon Graphics, Inc.  All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2.1 of the GNU Lesser General Public License 
  as published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

  Further, this software is distributed without any warranty that it is
  free of the rightful claim of any third person regarding infringement 
  or the like.  Any license provided herein, whether implied or 
  otherwise, applies only to this software file.  Patent licenses, if
  any, provided herein do not apply to combinations of this program with 
  other software, or any other product whatsoever.  

  You should have received a copy of the GNU Lesser General Public 
  License along with this program; if not, write the Free Software 
  Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, 
  USA.

  Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pky,
  Mountain View, CA 94043, or:

  http://www.sgi.com

  For further information regarding this notice, see:

  http://oss.sgi.com/projects/GenInfo/NoticeExplan

*/


/* $Header: /m_home/m_utkej/Argonne/cvs2svn/cvs/Open64/osprey1.0/libF77/pow_ii.c,v 1.1.1.1 2002-05-22 20:09:13 dsystem Exp $ */

#include "cmplrs/host.h"

int32 __powii(int32 ap, int32 n)
{
int32 pow;
/* 10/9/89 fix bug 5116 */

if(n != 0) {
        if (n<0) {
                /* if ap <> 1 or -1, then any other integer raised to
                 * a negative power would return a fraction, which is 
                 * rounded to 0.  if ap = 1 or -1 then depending on the
                 * power, if the power is odd, then result = -1, else = 1
                 */
                if ((ap!=1)&&(ap!=-1)) return(0); 
                n = -n;
                }
        pow=1;
        for( ; ; )
                {
                if(n & 01)
                        pow *= ap;
                if(n >>= 1)
                        ap *= ap;
                else
                        return(pow);
                }
     }
else return(1);
}

int64 __powll(int64 ap, int64 n)
{
int64 pow;
/* 10/9/89 fix bug 5116 */

if(n != 0) { 
        if (n<0) {
                /* if ap <> 1 or -1, then any other integer raised to
                 * a negative power would return a fraction, which is 
                 * rounded to 0.  if ap = 1 or -1 then depending on the
                 * power, if the power is odd, then result = -1, else = 1
                 */
                if ((ap!=1)&&(ap!=-1)) return(0); 
                n = -n;
                }
        pow=1;
        for( ; ; )
                {
                if(n & 01)
                        pow = pow * ap;
                if(n >>= 1)
                        ap = ap * ap;
                else
                        return(pow);
                }
     }
else return(1);
}

int64 __powli(int64 ap, int32 n)
{
int64 pow;
/* 10/9/89 fix bug 5116 */

if(n != 0) {
        if (n<0) {
                /* if ap <> 1 or -1, then any other integer raised to
                 * a negative power would return a fraction, which is 
                 * rounded to 0.  if ap = 1 or -1 then depending on the
                 * power, if the power is odd, then result = -1, else = 1
                 */
                if ((ap!=1)&&(ap!=-1)) return(0); 
                n = -n;
                }
        pow=1;
        for( ; ; )
                {
                if(n & 01)
                        pow = pow * ap;
                if(n >>= 1)
                        ap = ap * ap;
                else
                        return(pow);
                }
     }
else return(1);
}

int32 __powil(int32 ap, int64 n)
{
int32 pow;
/* 10/9/89 fix bug 5116 */

if(n != 0) {
        if (n<0) {
                /* if ap <> 1 or -1, then any other integer raised to
                 * a negative power would return a fraction, which is 
                 * rounded to 0.  if ap = 1 or -1 then depending on the
                 * power, if the power is odd, then result = -1, else = 1
                 */
                if ((ap!=1)&&(ap!=-1)) return(0); 
                n = -n;
                }
        pow=1;
        for( ; ; )
                {
                if(n & 01)
                        pow = pow * ap;
                if(n >>= 1)
                        ap = ap * ap;
                else
                        return(pow);
                }
     }
else return(1);
}

/* By-reference versions for backward compatibility. */

int32 pow_ii(int32 *ap, int32 *bp)
{
int32 pow;
pow=__powii(*ap,*bp);
return pow;
}

int64 pow_il(int32 *ap, int64 *bp)
{
int64 pow;
pow=__powil(*ap,*bp);
return pow;
}

int64 pow_li(int64 *ap, int32 *bp)
{
int64 pow;
pow=__powli(*ap,*bp);
return pow;
}

int64 pow_ll(int64 *ap, int64 *bp)
{
int64 pow;
pow=__powll(*ap,*bp);
return pow;
}