[BACK]Return to rshift.c CVS log [TXT][DIR] Up to [local] / OpenXM_contrib / gmp / mpn / generic

Diff for /OpenXM_contrib/gmp/mpn/generic/Attic/rshift.c between version 1.1.1.1 and 1.1.1.3

version 1.1.1.1, 2000/01/10 15:35:23 version 1.1.1.3, 2003/08/25 16:06:20
Line 1 
Line 1 
 /* mpn_rshift -- Shift right a low-level natural-number integer.  /* mpn_rshift -- Shift right low level.
   
 Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc.  Copyright 1991, 1993, 1994, 1996, 2000, 2001, 2002 Free Software Foundation,
   Inc.
   
 This file is part of the GNU MP Library.  This file is part of the GNU MP Library.
   
 The GNU MP Library is free software; you can redistribute it and/or modify  The GNU MP Library is free software; you can redistribute it and/or modify
 it under the terms of the GNU Library General Public License as published by  it under the terms of the GNU Lesser General Public License as published by
 the Free Software Foundation; either version 2 of the License, or (at your  the Free Software Foundation; either version 2.1 of the License, or (at your
 option) any later version.  option) any later version.
   
 The GNU MP Library is distributed in the hope that it will be useful, but  The GNU MP Library is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 License for more details.  License for more details.
   
 You should have received a copy of the GNU Library General Public License  You should have received a copy of the GNU Lesser General Public License
 along with the GNU MP Library; see the file COPYING.LIB.  If not, write to  along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,  the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 MA 02111-1307, USA. */  MA 02111-1307, USA. */
Line 22  MA 02111-1307, USA. */
Line 23  MA 02111-1307, USA. */
 #include "gmp.h"  #include "gmp.h"
 #include "gmp-impl.h"  #include "gmp-impl.h"
   
 /* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right  /* Shift U (pointed to by up and N limbs long) cnt bits to the right
    and store the USIZE least significant limbs of the result at WP.     and store the n least significant limbs of the result at rp.
    The bits shifted out to the right are returned.     The bits shifted out to the right are returned.
   
    Argument constraints:     Argument constraints:
    1. 0 < CNT < BITS_PER_MP_LIMB     1. 0 < cnt < GMP_NUMB_BITS.
    2. If the result is to be written over the input, WP must be <= UP.     2. If the result is to be written over the input, rp must be <= up.
 */  */
   
 mp_limb_t  mp_limb_t
 #if __STDC__  mpn_rshift (mp_ptr rp, mp_srcptr up, mp_size_t n, unsigned int cnt)
 mpn_rshift (register mp_ptr wp,  
             register mp_srcptr up, mp_size_t usize,  
             register unsigned int cnt)  
 #else  
 mpn_rshift (wp, up, usize, cnt)  
      register mp_ptr wp;  
      register mp_srcptr up;  
      mp_size_t usize;  
      register unsigned int cnt;  
 #endif  
 {  {
   register mp_limb_t high_limb, low_limb;    mp_limb_t high_limb, low_limb;
   register unsigned sh_1, sh_2;    unsigned int tnc;
   register mp_size_t i;    mp_size_t i;
   mp_limb_t retval;    mp_limb_t retval;
   
 #ifdef DEBUG    ASSERT (n >= 1);
   if (usize == 0 || cnt == 0)    ASSERT (cnt >= 1);
     abort ();    ASSERT (cnt < GMP_NUMB_BITS);
 #endif    ASSERT (MPN_SAME_OR_INCR_P (rp, up, n));
   
   sh_1 = cnt;    tnc = GMP_NUMB_BITS - cnt;
     high_limb = *up++;
     retval = (high_limb << tnc) & GMP_NUMB_MASK;
     low_limb = high_limb >> cnt;
   
 #if 0    for (i = n - 1; i != 0; i--)
   if (sh_1 == 0)  
     {      {
       if (wp != up)        high_limb = *up++;
         {        *rp++ = low_limb | ((high_limb << tnc) & GMP_NUMB_MASK);
           /* Copy from low end to high end, to allow specified input/output        low_limb = high_limb >> cnt;
              overlapping.  */  
           for (i = 0; i < usize; i++)  
             wp[i] = up[i];  
         }  
       return usize;  
     }      }
 #endif    *rp = low_limb;
   
   wp -= 1;  
   sh_2 = BITS_PER_MP_LIMB - sh_1;  
   high_limb = up[0];  
   retval = high_limb << sh_2;  
   low_limb = high_limb;  
   
   for (i = 1; i < usize; i++)  
     {  
       high_limb = up[i];  
       wp[i] = (low_limb >> sh_1) | (high_limb << sh_2);  
       low_limb = high_limb;  
     }  
   wp[i] = low_limb >> sh_1;  
   
   return retval;    return retval;
 }  }
Legend:
Removed from v.1.1.1.1  
changed lines
  Added in v.1.1.1.3
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>