[BACK]Return to fdiv_r_2exp.c CVS log [TXT][DIR] Up to [local] / OpenXM_contrib / gmp / mpz

Diff for /OpenXM_contrib/gmp/mpz/Attic/fdiv_r_2exp.c between version 1.1.1.1 and 1.1.1.2

version 1.1.1.1, 2000/01/10 15:35:27 version 1.1.1.2, 2000/09/09 14:12:51
Line 1 
Line 1 
 /* mpz_fdiv_r_2exp -- Divide a integer by 2**CNT and produce a remainder.  /* mpz_fdiv_r_2exp -- Divide a integer by 2**CNT and produce a remainder.
   
 Copyright (C) 1991, 1993, 1994, 1995 Free Software Foundation, Inc.  Copyright (C) 1991, 1993, 1994, 1995, 1998, 1999 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 65  mpz_fdiv_r_2exp (res, in, cnt)
Line 66  mpz_fdiv_r_2exp (res, in, cnt)
   else    else
     {      {
       /* The input operand is smaller than 2**CNT.  We perform a no-op,        /* The input operand is smaller than 2**CNT.  We perform a no-op,
          apart from that we might need to copy IN to RES.  */           apart from that we might need to copy IN to RES, and may need
            to round the result.  */
       res_size = in_size;        res_size = in_size;
       if (res->_mp_alloc < res_size)        if (res->_mp_alloc < res_size)
         _mpz_realloc (res, res_size);          _mpz_realloc (res, res_size);
Line 75  mpz_fdiv_r_2exp (res, in, cnt)
Line 77  mpz_fdiv_r_2exp (res, in, cnt)
   
   if (res != in)    if (res != in)
     MPN_COPY (res->_mp_d, in->_mp_d, limb_cnt);      MPN_COPY (res->_mp_d, in->_mp_d, limb_cnt);
     in_size = in->_mp_size;
   res->_mp_size = res_size;    res->_mp_size = res_size;
   if (in->_mp_size < 0 && res_size != 0)    if (in_size < 0 && res_size != 0)
     {      {
       /* Result should be 2^CNT - RES */        /* Result should be 2^CNT - RES */
       mpz_t tmp;        mpz_t tmp;
       MPZ_TMP_INIT (tmp, limb_cnt + 1);        MPZ_TMP_INIT (tmp, cnt/BITS_PER_MP_LIMB + 2);
       mpz_set_ui (tmp, 1L);        mpz_set_ui (tmp, 1L);
       mpz_mul_2exp (tmp, tmp, cnt);        mpz_mul_2exp (tmp, tmp, cnt);
       mpz_sub (res, tmp, res);        mpz_sub (res, tmp, res);
     }      }
 }  }
   
   /* This is an alternative ending of the above function using just low-level
      functions.  Tested, but perhaps excessive?  */
   #if 0
     if (in->_mp_size < 0 && res_size != 0)
       {
         /* Result should be 2^CNT - RES */
   
         mp_ptr rp;
   
         limb_cnt = cnt / BITS_PER_MP_LIMB;
   
         if (res->_mp_alloc <= limb_cnt)
           _mpz_realloc (res, limb_cnt + 1);
         rp = PTR(res);
         if (res_size > limb_cnt)
           {
             mpn_nz_neg (rp, rp, res_size);
             rp[limb_cnt] &= ~(~(mp_limb_t) 0 << cnt % BITS_PER_MP_LIMB);
             MPN_NORMALIZE_NOT_ZERO (rp, res_size);
           }
         else
           {
             mp_size_t i;
             mpn_nz_neg (rp, rp, res_size);
             for (i = res_size; i < limb_cnt; i++)
               rp[i] = ~ (mp_limb_t) 0;
             res_size = limb_cnt;
             if (cnt % BITS_PER_MP_LIMB != 0)
               {
                 rp[res_size] = ((mp_limb_t) 1 << (cnt % BITS_PER_MP_LIMB)) - 1;
                 res_size++;
               }
             else
               MPN_NORMALIZE_NOT_ZERO (rp, res_size);
           }
       }
     SIZ(res) = res_size;
   }
   
   static void
   mpn_nz_neg (rp, sp, n)
        mp_ptr rp, sp;
        mp_size_t n;
   {
     mp_size_t i;
     mp_limb_t x;
   
     x = sp[0];
     rp[0] = -x;
     for (i = 1; x == 0; i++)
       {
         x = sp[i];
         rp[i] = -x;
       }
   
     for (; i < n; i++)
       {
         rp[i] = ~sp[i];
       }
   }
   #endif
Legend:
Removed from v.1.1.1.1  
changed lines
  Added in v.1.1.1.2
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>