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Diff for /OpenXM_contrib/gmp/mpz/Attic/get_d.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 14:12:52
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 /* double mpz_get_d (mpz_t src) -- Return the double approximation to SRC.  /* double mpz_get_d (mpz_t src) -- Return the double approximation to SRC.
   
 Copyright (C) 1996 Free Software Foundation, Inc.  Copyright (C) 1996, 1997, 2000 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. */
   
 #include "gmp.h"  #include "gmp.h"
 #include "gmp-impl.h"  #include "gmp-impl.h"
   #include "longlong.h"
   
   
   static int
   #if __STDC__
   mpn_zero_p (mp_ptr p, mp_size_t n)
   #else
   mpn_zero_p (p, n)
        mp_ptr p;
        mp_size_t n;
   #endif
   {
     mp_size_t i;
   
     for (i = 0; i < n; i++)
       {
         if (p[i] != 0)
           return 0;
       }
   
     return 1;
   }
   
   
 double  double
 #if __STDC__  #if __STDC__
 mpz_get_d (mpz_srcptr src)  mpz_get_d (mpz_srcptr src)
Line 31  mpz_get_d (src)
Line 54  mpz_get_d (src)
 #endif  #endif
 {  {
   double res;    double res;
   mp_size_t size, i, n_limbs_to_use;    mp_size_t size;
   int negative;    int negative;
   mp_ptr qp;    mp_ptr qp;
     mp_limb_t hz, lz;
     int cnt;
   
   size = SIZ(src);    size = SIZ(src);
   if (size == 0)    if (size == 0)
Line 43  mpz_get_d (src)
Line 68  mpz_get_d (src)
   size = ABS (size);    size = ABS (size);
   qp = PTR(src);    qp = PTR(src);
   
   res = qp[size - 1];    if (size == 1)
   n_limbs_to_use = MIN (LIMBS_PER_DOUBLE, size);      {
   for (i = 2; i <= n_limbs_to_use; i++)        res = qp[size - 1];
     res = res * MP_BASE_AS_DOUBLE + qp[size - i];      }
     else if (size == 2)
       {
         res = MP_BASE_AS_DOUBLE * qp[size - 1] + qp[size - 2];
       }
     else
       {
         count_leading_zeros (cnt, qp[size - 1]);
   
   res = __gmp_scale2 (res, (size - n_limbs_to_use) * BITS_PER_MP_LIMB);  #if BITS_PER_MP_LIMB == 32
         if (cnt == 0)
           {
             hz = qp[size - 1];
             lz = qp[size - 2];
           }
         else
           {
             hz = (qp[size - 1] << cnt) | (qp[size - 2] >> BITS_PER_MP_LIMB - cnt);
             lz = (qp[size - 2] << cnt) | (qp[size - 3] >> BITS_PER_MP_LIMB - cnt);
           }
   #if _GMP_IEEE_FLOATS
         /* Take bits from less significant limbs, but only if they may affect
            the result.  */
         if ((lz & 0x7ff) == 0x400)
           {
             if (cnt != 0)
               lz += ((qp[size - 3] << cnt) != 0 || ! mpn_zero_p (qp, size - 3));
             else
               lz += (! mpn_zero_p (qp, size - 2));
           }
   #endif
         res = MP_BASE_AS_DOUBLE * hz + lz;
         res = __gmp_scale2 (res, (size - 2) * BITS_PER_MP_LIMB - cnt);
   #endif
   #if BITS_PER_MP_LIMB == 64
         if (cnt == 0)
           hz = qp[size - 1];
         else
           hz = (qp[size - 1] << cnt) | (qp[size - 2] >> BITS_PER_MP_LIMB - cnt);
   #if _GMP_IEEE_FLOATS
         if ((hz & 0x7ff) == 0x400)
           {
             if (cnt != 0)
               hz += ((qp[size - 2] << cnt) != 0 || ! mpn_zero_p (qp, size - 2));
             else
               hz += (! mpn_zero_p (qp, size - 1));
           }
   #endif
         res = hz;
         res = __gmp_scale2 (res, (size - 1) * BITS_PER_MP_LIMB - cnt);
   #endif
       }
   
   return negative ? -res : res;    return negative ? -res : res;
 }  }
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  Added in v.1.1.1.2
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